* [PATCH RFC v2 02/12] KEYS: CA link restriction
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Add a new link restriction. Restrict the addition of keys in a keyring
based on the key to be added being a CA (self-signed) or by being
vouched for by a key in either the built-in or the secondary trusted
keyrings.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: Removed secondary keyring references
---
certs/system_keyring.c | 21 +++++++++++
crypto/asymmetric_keys/restrict.c | 60 +++++++++++++++++++++++++++++++
include/crypto/public_key.h | 5 +++
include/keys/system_keyring.h | 6 ++++
4 files changed, 92 insertions(+)
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 692365dee2bd..0a7b16c28a72 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -21,6 +21,9 @@
static struct key *builtin_trusted_keys;
#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
static struct key *secondary_trusted_keys;
+#define system_trusted_keys secondary_trusted_keys
+#else
+#define system_trusted_keys builtin_trusted_keys
#endif
#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
static struct key *platform_trusted_keys;
@@ -45,6 +48,24 @@ int restrict_link_by_builtin_trusted(struct key *dest_keyring,
builtin_trusted_keys);
}
+/**
+ * restrict_link_by_system_trusted_or_ca - Restrict keyring
+ * addition by being a CA or vouched by the system trusted keyrings.
+ *
+ * Restrict the addition of keys in a keyring based on the key-to-be-added
+ * being a CA (self signed) or by being vouched for by a key in either
+ * the built-in or the secondary system keyrings.
+ */
+int restrict_link_by_system_trusted_or_ca(
+ struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *restrict_key)
+{
+ return restrict_link_by_ca(dest_keyring, type, payload,
+ system_trusted_keys);
+}
+
#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
/**
* restrict_link_by_builtin_and_secondary_trusted - Restrict keyring
diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c
index 84cefe3b3585..75e4379226e8 100644
--- a/crypto/asymmetric_keys/restrict.c
+++ b/crypto/asymmetric_keys/restrict.c
@@ -108,6 +108,66 @@ int restrict_link_by_signature(struct key *dest_keyring,
return ret;
}
+/**
+ * restrict_link_by_ca - Restrict additions to a ring of public keys
+ * based on it being a CA
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @trusted: A key or ring of keys that can be used to vouch for the new cert.
+ *
+ * Check if the new certificate is a CA or if they key can be vouched for
+ * by keys already linked in the destination keyring or the trusted
+ * keyring. If one of those is the signing key or it is self signed, then
+ * mark the new certificate as being ok to link.
+ *
+ * Returns 0 if the new certificate was accepted, -ENOKEY if we could not find
+ * a matching parent certificate in the trusted list. -ENOPKG if the signature
+ * uses unsupported crypto, or some other error if there is a matching
+ * certificate but the signature check cannot be performed.
+ */
+int restrict_link_by_ca(struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *trust_keyring)
+{
+ const struct public_key_signature *sig;
+ const struct public_key *pkey;
+ struct key *key;
+ int ret;
+
+ if (type != &key_type_asymmetric)
+ return -EOPNOTSUPP;
+
+ sig = payload->data[asym_auth];
+ if (!sig)
+ return -ENOPKG;
+
+ if (!sig->auth_ids[0] && !sig->auth_ids[1])
+ return -ENOKEY;
+
+ pkey = payload->data[asym_crypto];
+ if (!pkey)
+ return -ENOPKG;
+
+ ret = public_key_verify_signature(pkey, sig);
+ if (!ret)
+ return 0;
+
+ if (!trust_keyring)
+ return -ENOKEY;
+
+ key = find_asymmetric_key(trust_keyring,
+ sig->auth_ids[0], sig->auth_ids[1],
+ false);
+ if (IS_ERR(key))
+ return -ENOKEY;
+
+ ret = verify_signature(key, sig);
+ key_put(key);
+ return ret;
+}
+
static bool match_either_id(const struct asymmetric_key_ids *pair,
const struct asymmetric_key_id *single)
{
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 47accec68cb0..545af1ea57de 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -71,6 +71,11 @@ extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
const union key_payload *payload,
struct key *trusted);
+extern int restrict_link_by_ca(struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *trust_keyring);
+
extern int query_asymmetric_key(const struct kernel_pkey_params *,
struct kernel_pkey_query *);
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index 6acd3cf13a18..2041254d74f4 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -28,6 +28,12 @@ static inline __init int load_module_cert(struct key *keyring)
#endif
+extern int restrict_link_by_system_trusted_or_ca(
+ struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *restrict_key);
+
#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
extern int restrict_link_by_builtin_and_secondary_trusted(
struct key *keyring,
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 01/12] integrity: Introduce a Linux keyring for the Machine Owner Key (MOK)
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Many UEFI Linux distributions boot using shim. The UEFI shim provides
what is called Machine Owner Keys (MOK). Shim uses both the UEFI Secure
Boot DB and MOK keys to validate the next step in the boot chain. The
MOK facility can be used to import user generated keys. These keys can
be used to sign an end-users development kernel build. When Linux
boots, both UEFI Secure Boot DB and MOK keys get loaded in the Linux
.platform keyring.
Add a new Linux keyring called .mok. This keyring shall contain just
MOK keys and not the remaining keys in the platform keyring. This new
.mok keyring will be used in follow on patches. Unlike keys in the
platform keyring, keys contained in the .mok keyring will be trusted
within the kernel if the end-user has chosen to do so.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: Removed destory keyring code
---
security/integrity/Makefile | 3 ++-
security/integrity/digsig.c | 1 +
security/integrity/integrity.h | 3 ++-
.../integrity/platform_certs/mok_keyring.c | 21 +++++++++++++++++++
4 files changed, 26 insertions(+), 2 deletions(-)
create mode 100644 security/integrity/platform_certs/mok_keyring.c
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index 7ee39d66cf16..8e2e98cba1f6 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -9,7 +9,8 @@ integrity-y := iint.o
integrity-$(CONFIG_INTEGRITY_AUDIT) += integrity_audit.o
integrity-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o
integrity-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o
-integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o
+integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o \
+ platform_certs/mok_keyring.o
integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \
platform_certs/load_uefi.o \
platform_certs/keyring_handler.o
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 3b06a01bd0fd..e07334504ef1 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -30,6 +30,7 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
".ima",
#endif
".platform",
+ ".mok",
};
#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 547425c20e11..e0e17ccba2e6 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -151,7 +151,8 @@ int integrity_kernel_read(struct file *file, loff_t offset,
#define INTEGRITY_KEYRING_EVM 0
#define INTEGRITY_KEYRING_IMA 1
#define INTEGRITY_KEYRING_PLATFORM 2
-#define INTEGRITY_KEYRING_MAX 3
+#define INTEGRITY_KEYRING_MOK 3
+#define INTEGRITY_KEYRING_MAX 4
extern struct dentry *integrity_dir;
diff --git a/security/integrity/platform_certs/mok_keyring.c b/security/integrity/platform_certs/mok_keyring.c
new file mode 100644
index 000000000000..b1ee45b77731
--- /dev/null
+++ b/security/integrity/platform_certs/mok_keyring.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * MOK keyring routines.
+ *
+ * Copyright (c) 2021, Oracle and/or its affiliates.
+ */
+
+#include "../integrity.h"
+
+static __init int mok_keyring_init(void)
+{
+ int rc;
+
+ rc = integrity_init_keyring(INTEGRITY_KEYRING_MOK);
+ if (rc)
+ return rc;
+
+ pr_notice("MOK Keyring initialized\n");
+ return 0;
+}
+device_initcall(mok_keyring_init);
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 00/12] Enroll kernel keys thru MOK
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
Many UEFI Linux distributions boot using shim. The UEFI shim provides
what is called Machine Owner Keys (MOK). Shim uses both the UEFI Secure
Boot DB and MOK keys to validate the next step in the boot chain. The
MOK facility can be used to import user generated keys. These keys can
be used to sign an end-user development kernel build. When Linux boots,
pre-boot keys (both UEFI Secure Boot DB and MOK keys) get loaded in the
Linux .platform keyring.
Currently, pre-boot keys are not trusted within the Linux trust boundary
[1]. These platform keys can only be used for kexec. If an end-user
wants to use their own key within the Linux trust boundary, they must
either compile it into the kernel themselves or use the insert-sys-cert
script. Both options present a problem. Many end-users do not want to
compile their own kernels. With the insert-sys-cert option, there are
missing upstream changes [2]. Also, with the insert-sys-cert option,
the end-user must re-sign their kernel again with their own key, and
then insert that key into the MOK db. Another problem with
insert-sys-cert is that only a single key can be inserted into a
compressed kernel.
Having the ability to insert a key into the Linux trust boundary opens
up various possibilities. The end-user can use a pre-built kernel and
sign their own kernel modules. It also opens up the ability for an
end-user to more easily use digital signature based IMA-appraisal. To
get a key into the ima keyring, it must be signed by a key within the
Linux trust boundary.
Downstream Linux distros try to have a single signed kernel for each
architecture. Each end-user may use this kernel in entirely different
ways. Some downstream kernels have chosen to always trust platform keys
within the Linux trust boundary for kernel module signing. These
kernels have no way of using digital signature base IMA appraisal.
This series introduces a new Linux kernel keyring containing the Machine
Owner Keys (MOK) called .mok. It also adds a new MOK variable to shim.
This variable allows the end-user to decide if they want to trust keys
enrolled in the MOK within the Linux trust boundary. By default,
nothing changes; MOK keys are not trusted within the Linux kernel. They
are only trusted after the end-user makes the decision themselves. The
end-user would set this through mokutil using a new --trust-mok option
[3]. This would work similar to how the kernel uses MOK variables to
enable/disable signature validation as well as use/ignore the db.
When shim boots, it mirrors the new MokTML Boot Services variable to a
new MokListTrustedRT Runtime Services variable and extends PCR14.
MokListTrustedRT is written without EFI_VARIABLE_NON_VOLATILE set,
preventing an end-user from setting it after booting and doing a kexec.
When the kernel boots, if MokListTrustedRT is set and
EFI_VARIABLE_NON_VOLATILE is not set, the MokListRT is loaded into the
mok keyring instead of the platform keyring. Mimi has suggested that
only CA keys or keys that can be vouched for by other kernel keys be
loaded into this keyring. All other certs will load into the platform
keyring instead.
The .mok keyring contains a new keyring permission that only allows CA
keys to be loaded. If the permission fails, the key is later loaded into
the platform keyring. After all keys are added into the .mok keyring,
they are linked to either the builtin or secondary trusted keyring.
After the link is created, keys contained in the .mok keyring will
automatically be searched when searching either builtin or secondary
trusted keys.
Secure Boot keys will never be trusted. They will always be loaded into
the platform keyring. If an end-user wanted to trust one, they would
need to enroll it into the MOK.
I have included links to both the mokutil [3] and shim [4] changes I
have made to support this new functionality.
V2 changes:
- The .mok keyring persists past boot
- Removed the unrestricted move into the secondary keyring
- Removed the keyring move bypass patch
- Added restrictions to allow the .mok to be linked to either the
builtin or secondary keyrings
- Secondary keyring dependency has been removed
[1] https://lore.kernel.org/lkml/1556221605.24945.3.camel@HansenPartnership.com/
[2] https://lore.kernel.org/patchwork/cover/902768/
[3] https://github.com/esnowberg/mokutil/tree/0.3.0-mokvars-v2
[4] https://github.com/esnowberg/shim/tree/mokvars-v2
Eric Snowberg (12):
integrity: Introduce a Linux keyring for the Machine Owner Key (MOK)
KEYS: CA link restriction
integrity: Trust MOK keys if MokListTrustedRT found
integrity: add add_to_mok_keyring
integrity: restrict INTEGRITY_KEYRING_MOK to
restrict_link_by_system_trusted_or_ca
integrity: accessor function to get trust_moklist
integrity: add new keyring handler for mok keys
integrity: Suppress error message for keys added to the mok keyring
KEYS: add a reference to mok keyring
KEYS: link system_trusted_keys to mok_trusted_keys
integrity: Do not allow mok keyring updates following init
integrity: store reference to mok keyring
certs/system_keyring.c | 47 ++++++++++
crypto/asymmetric_keys/restrict.c | 60 +++++++++++++
include/crypto/public_key.h | 5 ++
include/keys/system_keyring.h | 10 +++
security/integrity/Makefile | 3 +-
security/integrity/digsig.c | 16 +++-
security/integrity/integrity.h | 12 ++-
.../platform_certs/keyring_handler.c | 17 +++-
.../platform_certs/keyring_handler.h | 5 ++
security/integrity/platform_certs/load_uefi.c | 4 +-
.../integrity/platform_certs/mok_keyring.c | 85 +++++++++++++++++++
11 files changed, 256 insertions(+), 8 deletions(-)
create mode 100644 security/integrity/platform_certs/mok_keyring.c
base-commit: ff1176468d368232b684f75e82563369208bc371
--
2.18.4
^ permalink raw reply
* [PATCH RFC v2 05/12] integrity: restrict INTEGRITY_KEYRING_MOK to restrict_link_by_system_trusted_or_ca
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Set the restriction check for INTEGRITY_KEYRING_MOK keys to
restrict_link_by_system_trusted_or_ca. This will only allow keys
into the mok keyring that are either a CA or trusted by a key contained
within the builtin or secondary trusted keyring.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: Added !IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING check so mok
keyring gets created even when it isn't enabled
---
security/integrity/digsig.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index e07334504ef1..2f6898c89f60 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -132,7 +132,7 @@ int __init integrity_init_keyring(const unsigned int id)
goto out;
}
- if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING))
+ if (!IS_ENABLED(CONFIG_INTEGRITY_TRUSTED_KEYRING) && id != INTEGRITY_KEYRING_MOK)
return 0;
restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
@@ -140,6 +140,11 @@ int __init integrity_init_keyring(const unsigned int id)
return -ENOMEM;
restriction->check = restrict_link_to_ima;
+ if (id == INTEGRITY_KEYRING_MOK)
+ restriction->check = restrict_link_by_system_trusted_or_ca;
+ else
+ restriction->check = restrict_link_to_ima;
+
perm |= KEY_USR_WRITE;
out:
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 10/12] KEYS: link system_trusted_keys to mok_trusted_keys
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Allow the .mok keyring to be linked to either the builtin_trusted_keys
or the secondary_trusted_keys. If CONFIG_SECONDARY_TRUSTED_KEYRING is
enabled, mok keys are linked to the secondary_trusted_keys. Otherwise
they are linked to the builtin_trusted_keys. After the link is created,
keys contained in the .mok keyring will automatically be searched when
searching either builtin_trusted_keys or secondary_trusted_keys.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v2: Initial version
---
certs/system_keyring.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index dcaf74102ab2..b27ae30eaadc 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -45,6 +45,15 @@ int restrict_link_by_builtin_trusted(struct key *dest_keyring,
const union key_payload *payload,
struct key *restriction_key)
{
+ /* If the secondary trusted keyring is not enabled, we may link
+ * through to the mok keyring and the search may follow that link.
+ */
+ if (mok_trusted_keys && type == &key_type_keyring &&
+ dest_keyring == builtin_trusted_keys &&
+ payload == &mok_trusted_keys->payload)
+ /* Allow the mok keyring to be added to the builtin */
+ return 0;
+
return restrict_link_by_signature(dest_keyring, type, payload,
builtin_trusted_keys);
}
@@ -91,6 +100,15 @@ int restrict_link_by_builtin_and_secondary_trusted(
/* Allow the builtin keyring to be added to the secondary */
return 0;
+ /* If we have a secondary trusted keyring, it may contain a link
+ * through to the mok keyring and the search may follow that link.
+ */
+ if (mok_trusted_keys && type == &key_type_keyring &&
+ dest_keyring == secondary_trusted_keys &&
+ payload == &mok_trusted_keys->payload)
+ /* Allow the mok keyring to be added to the secondary */
+ return 0;
+
return restrict_link_by_signature(dest_keyring, type, payload,
secondary_trusted_keys);
}
@@ -321,5 +339,8 @@ void __init set_platform_trusted_keys(struct key *keyring)
void __init set_mok_trusted_keys(struct key *keyring)
{
mok_trusted_keys = keyring;
+
+ if (key_link(system_trusted_keys, mok_trusted_keys) < 0)
+ panic("Can't link (mok) trusted keyrings\n");
}
#endif
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 12/12] integrity: store reference to mok keyring
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Store a reference to the mok keyring in system keyring code. The
reference is only set when trust_moklist is true. This prevents the mok
keyring from linking to either the builtin or secondary trusted keyrings
with an empty mok list.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v2: Initial version
---
security/integrity/digsig.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 3a12cc85b528..cf13f4c56517 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -112,6 +112,8 @@ static int __init __integrity_init_keyring(const unsigned int id,
} else {
if (id == INTEGRITY_KEYRING_PLATFORM)
set_platform_trusted_keys(keyring[id]);
+ if (id == INTEGRITY_KEYRING_MOK && trust_moklist())
+ set_mok_trusted_keys(keyring[id]);
if (id == INTEGRITY_KEYRING_IMA)
load_module_cert(keyring[id]);
}
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 11/12] integrity: Do not allow mok keyring updates following init
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
The mok keyring is setup during init. No additional keys should be allowed
to be added afterwards. Leave the permission as read only.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v2: Initial version
---
security/integrity/digsig.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index be4860c596b9..3a12cc85b528 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -145,7 +145,8 @@ int __init integrity_init_keyring(const unsigned int id)
else
restriction->check = restrict_link_to_ima;
- perm |= KEY_USR_WRITE;
+ if (id != INTEGRITY_KEYRING_MOK)
+ perm |= KEY_USR_WRITE;
out:
return __integrity_init_keyring(id, perm, restriction);
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 03/12] integrity: Trust MOK keys if MokListTrustedRT found
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
A new Machine Owner Key (MOK) variable called MokListTrustedRT has been
introduced in shim. When this UEFI variable is set, it indicates the
end-user has made the decision themself that they wish to trust MOK keys
within the Linux trust boundary. It is not an error if this variable
does not exist. If it does not exist, the MOK keys should not be trusted
within the kernel.
MOK variables are mirrored from Boot Services to Runtime Services. When
shim sees the new MokTML BS variable, it will create a new variable
(before Exit Boot Services is called) called MokListTrustedRT without
EFI_VARIABLE_NON_VOLATILE set. Following Exit Boot Services, UEFI
variables can only be set and created with SetVariable if both
EFI_VARIABLE_RUNTIME_ACCESS & EFI_VARIABLE_NON_VOLATILE are set.
Therefore, this can not be defeated by simply creating a
MokListTrustedRT variable from Linux, the existence of
EFI_VARIABLE_NON_VOLATILE will cause uefi_check_trust_mok_keys to return
false.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: removed mok_keyring_trust_setup function
---
.../integrity/platform_certs/mok_keyring.c | 27 +++++++++++++++++++
1 file changed, 27 insertions(+)
diff --git a/security/integrity/platform_certs/mok_keyring.c b/security/integrity/platform_certs/mok_keyring.c
index b1ee45b77731..fe4f2d336260 100644
--- a/security/integrity/platform_certs/mok_keyring.c
+++ b/security/integrity/platform_certs/mok_keyring.c
@@ -5,6 +5,7 @@
* Copyright (c) 2021, Oracle and/or its affiliates.
*/
+#include <linux/efi.h>
#include "../integrity.h"
static __init int mok_keyring_init(void)
@@ -19,3 +20,29 @@ static __init int mok_keyring_init(void)
return 0;
}
device_initcall(mok_keyring_init);
+
+/*
+ * Try to load the MokListTrustedRT UEFI variable to see if we should trust
+ * the mok keys within the kernel. It is not an error if this variable
+ * does not exist. If it does not exist, mok keys should not be trusted
+ * within the kernel.
+ */
+static __init bool uefi_check_trust_mok_keys(void)
+{
+ efi_status_t status;
+ unsigned int mtrust = 0;
+ unsigned long size = sizeof(mtrust);
+ efi_guid_t guid = EFI_SHIM_LOCK_GUID;
+ u32 attr;
+
+ status = efi.get_variable(L"MokListTrustedRT", &guid, &attr, &size, &mtrust);
+
+ /*
+ * The EFI_VARIABLE_NON_VOLATILE check is to verify MokListTrustedRT
+ * was set thru shim mirrioring and not by a user from the host os.
+ * According to the UEFI spec, once EBS is performed, SetVariable()
+ * will succeed only when both EFI_VARIABLE_RUNTIME_ACCESS &
+ * EFI_VARIABLE_NON_VOLATILE are set.
+ */
+ return (status == EFI_SUCCESS && (!(attr & EFI_VARIABLE_NON_VOLATILE)));
+}
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 07/12] integrity: add new keyring handler for mok keys
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Currently both Secure Boot DB and Machine Owner Keys (MOK) go through
the same keyring handler (get_handler_for_db). With the addition of the
new mok keyring, the end-user may choose to trust MOK keys.
Introduce a new keyring handler specific for mok keys. If mok keys are
trusted by the end-user, use the new keyring handler instead.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: Unmodified from v1
---
.../integrity/platform_certs/keyring_handler.c | 17 ++++++++++++++++-
.../integrity/platform_certs/keyring_handler.h | 5 +++++
security/integrity/platform_certs/load_uefi.c | 4 ++--
3 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c
index 5604bd57c990..1e15b65abc9f 100644
--- a/security/integrity/platform_certs/keyring_handler.c
+++ b/security/integrity/platform_certs/keyring_handler.c
@@ -66,7 +66,7 @@ static __init void uefi_revocation_list_x509(const char *source,
/*
* Return the appropriate handler for particular signature list types found in
- * the UEFI db and MokListRT tables.
+ * the UEFI db tables.
*/
__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
{
@@ -75,6 +75,21 @@ __init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
return 0;
}
+/*
+ * Return the appropriate handler for particular signature list types found in
+ * the MokListRT tables.
+ */
+__init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
+{
+ if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0) {
+ if (trust_moklist())
+ return add_to_mok_keyring;
+ else
+ return add_to_platform_keyring;
+ }
+ return 0;
+}
+
/*
* Return the appropriate handler for particular signature list types found in
* the UEFI dbx and MokListXRT tables.
diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h
index 2462bfa08fe3..284558f30411 100644
--- a/security/integrity/platform_certs/keyring_handler.h
+++ b/security/integrity/platform_certs/keyring_handler.h
@@ -24,6 +24,11 @@ void blacklist_binary(const char *source, const void *data, size_t len);
*/
efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type);
+/*
+ * Return the handler for particular signature list types found in the mok.
+ */
+efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type);
+
/*
* Return the handler for particular signature list types found in the dbx.
*/
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index f290f78c3f30..c1bfd1cd7cc3 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -94,7 +94,7 @@ static int __init load_moklist_certs(void)
rc = parse_efi_signature_list("UEFI:MokListRT (MOKvar table)",
mokvar_entry->data,
mokvar_entry->data_size,
- get_handler_for_db);
+ get_handler_for_mok);
/* All done if that worked. */
if (!rc)
return rc;
@@ -109,7 +109,7 @@ static int __init load_moklist_certs(void)
mok = get_cert_list(L"MokListRT", &mok_var, &moksize, &status);
if (mok) {
rc = parse_efi_signature_list("UEFI:MokListRT",
- mok, moksize, get_handler_for_db);
+ mok, moksize, get_handler_for_mok);
kfree(mok);
if (rc)
pr_err("Couldn't parse MokListRT signatures: %d\n", rc);
--
2.18.4
^ permalink raw reply related
* [PATCH RFC v2 04/12] integrity: add add_to_mok_keyring
From: Eric Snowberg @ 2021-07-26 17:13 UTC (permalink / raw)
To: keyrings, linux-integrity, zohar, dhowells, dwmw2, herbert, davem,
jarkko, jmorris, serge
Cc: eric.snowberg, keescook, gregkh, torvalds, scott.branden,
weiyongjun1, nayna, ebiggers, ardb, nramas, lszubowi,
linux-kernel, linux-crypto, linux-security-module,
James.Bottomley, pjones, glin, konrad.wilk
In-Reply-To: <20210726171319.3133879-1-eric.snowberg@oracle.com>
Add the ability to load Machine Owner Key (MOK) keys to the mok keyring.
If the permissions do not allow the key to be added to the mok keyring
this is not an error, add it to the platform keyring instead.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: Unmodified from v1
---
security/integrity/integrity.h | 4 ++++
.../integrity/platform_certs/mok_keyring.c | 21 +++++++++++++++++++
2 files changed, 25 insertions(+)
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index e0e17ccba2e6..60d5c7ba05b2 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -278,9 +278,13 @@ integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
void __init add_to_platform_keyring(const char *source, const void *data,
size_t len);
+void __init add_to_mok_keyring(const char *source, const void *data, size_t len);
#else
static inline void __init add_to_platform_keyring(const char *source,
const void *data, size_t len)
{
}
+void __init add_to_mok_keyring(const char *source, const void *data, size_t len)
+{
+}
#endif
diff --git a/security/integrity/platform_certs/mok_keyring.c b/security/integrity/platform_certs/mok_keyring.c
index fe4f2d336260..f260edac0863 100644
--- a/security/integrity/platform_certs/mok_keyring.c
+++ b/security/integrity/platform_certs/mok_keyring.c
@@ -21,6 +21,27 @@ static __init int mok_keyring_init(void)
}
device_initcall(mok_keyring_init);
+void __init add_to_mok_keyring(const char *source, const void *data, size_t len)
+{
+ key_perm_t perm;
+ int rc;
+
+ perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW;
+ rc = integrity_load_cert(INTEGRITY_KEYRING_MOK, source, data, len, perm);
+
+ /*
+ * If the mok keyring restrictions prevented the cert from loading,
+ * this is not an error. Just load it into the platform keyring
+ * instead.
+ */
+ if (rc)
+ rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source,
+ data, len, perm);
+
+ if (rc)
+ pr_info("Error adding keys to mok keyring %s\n", source);
+}
+
/*
* Try to load the MokListTrustedRT UEFI variable to see if we should trust
* the mok keys within the kernel. It is not an error if this variable
--
2.18.4
^ permalink raw reply related
* [RFC][PATCH v2 06/12] diglim: Interfaces - digest_list_add, digest_list_del
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce <securityfs>/integrity/diglim/digest_list_add, which can be used
to upload a digest list and add the digests to the hash table; passed data
are interpreted as file path if the first byte is / or as the digest list
itself otherwise. ima_measure_critical_data() is called to calculate the
digest of the digest list and eventually, if an appropriate rule is set in
the IMA policy, to measure it.
Also introduce <securityfs>/integrity/diglim/digest_list_del, which can be
used to upload a digest list and delete the digests from the hash table;
data are interpreted in the same way as described for digest_list_add.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
.../security/diglim/implementation.rst | 9 +
MAINTAINERS | 1 +
include/linux/kernel_read_file.h | 1 +
security/integrity/diglim/Makefile | 2 +-
security/integrity/diglim/diglim.h | 2 +
security/integrity/diglim/fs.c | 239 ++++++++++++++++++
security/integrity/integrity.h | 4 +
7 files changed, 257 insertions(+), 1 deletion(-)
create mode 100644 security/integrity/diglim/fs.c
diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst
index 9d679567a037..fc0cd8810a80 100644
--- a/Documentation/security/diglim/implementation.rst
+++ b/Documentation/security/diglim/implementation.rst
@@ -244,3 +244,12 @@ back when one of the steps fails.
#. digest_list_parse() deletes the struct digest_list_item on unsuccessful
add or successful delete.
+
+
+Interfaces
+----------
+
+This section introduces the interfaces in
+``<securityfs>/integrity/diglim`` necessary to interact with DIGLIM.
+
+.. kernel-doc:: security/integrity/diglim/fs.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 77c3613c600a..0672128fae7f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5464,6 +5464,7 @@ F: Documentation/security/diglim/introduction.rst
F: include/linux/diglim.h
F: include/uapi/linux/diglim.h
F: security/integrity/diglim/diglim.h
+F: security/integrity/diglim/fs.c
F: security/integrity/diglim/methods.c
F: security/integrity/diglim/parser.c
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
index 575ffa1031d3..636ecdfdc616 100644
--- a/include/linux/kernel_read_file.h
+++ b/include/linux/kernel_read_file.h
@@ -14,6 +14,7 @@
id(KEXEC_INITRAMFS, kexec-initramfs) \
id(POLICY, security-policy) \
id(X509_CERTIFICATE, x509-certificate) \
+ id(DIGEST_LIST, digest-list) \
id(MAX_ID, )
#define __fid_enumify(ENUM, dummy) READING_ ## ENUM,
diff --git a/security/integrity/diglim/Makefile b/security/integrity/diglim/Makefile
index 34e4e154fff3..ac345afdf5dd 100644
--- a/security/integrity/diglim/Makefile
+++ b/security/integrity/diglim/Makefile
@@ -5,4 +5,4 @@
obj-$(CONFIG_DIGLIM) += diglim.o
-diglim-y := methods.o parser.o
+diglim-y := methods.o parser.o fs.o
diff --git a/security/integrity/diglim/diglim.h b/security/integrity/diglim/diglim.h
index 3adc218a0325..819703175eda 100644
--- a/security/integrity/diglim/diglim.h
+++ b/security/integrity/diglim/diglim.h
@@ -22,6 +22,8 @@
#include <linux/hash_info.h>
#include <linux/diglim.h>
+#include "../integrity.h"
+
#define MAX_DIGEST_SIZE 64
#define HASH_BITS 10
#define DIGLIM_HTABLE_SIZE (1 << HASH_BITS)
diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c
new file mode 100644
index 000000000000..07a0d75a0e33
--- /dev/null
+++ b/security/integrity/diglim/fs.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Functions for the interfaces exposed in securityfs.
+ */
+
+#include <linux/fcntl.h>
+#include <linux/kernel_read_file.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/seq_file.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/parser.h>
+#include <linux/vmalloc.h>
+#include <linux/namei.h>
+#include <linux/ima.h>
+
+#include "diglim.h"
+
+#define MAX_DIGEST_LIST_SIZE (64 * 1024 * 1024 - 1)
+
+static struct dentry *diglim_dir;
+/**
+ * DOC: digest_list_add
+ *
+ * digest_list_add can be used to upload a digest list and add the digests
+ * to the hash table; passed data are interpreted as file path if the first
+ * byte is ``/`` or as the digest list itself otherwise.
+ *
+ * ima_measure_critical_data() is called to calculate the digest of the
+ * digest list and eventually, if an appropriate rule is set in the IMA
+ * policy, to measure it.
+ */
+static struct dentry *digest_list_add_dentry;
+/**
+ * DOC: digest_list_del
+ *
+ * digest_list_del can be used to upload a digest list and delete the
+ * digests from the hash table; data are interpreted in the same way as
+ * described for digest_list_add.
+ */
+static struct dentry *digest_list_del_dentry;
+char digest_label[NAME_MAX + 1];
+
+/*
+ * digest_list_read: read and parse the digest list from the path
+ */
+static ssize_t digest_list_read(char *path, enum ops op)
+{
+ void *data = NULL;
+ char *datap;
+ size_t size;
+ u8 actions = 0;
+ struct file *file;
+ char event_name[NAME_MAX + 9 + 1];
+ u8 digest[IMA_MAX_DIGEST_SIZE] = { 0 };
+ enum hash_algo algo;
+ int rc, pathlen = strlen(path);
+
+ /* Remove \n. */
+ datap = path;
+ strsep(&datap, "\n");
+
+ file = filp_open(path, O_RDONLY, 0);
+ if (IS_ERR(file)) {
+ pr_err("unable to open file: %s (%ld)", path, PTR_ERR(file));
+ return PTR_ERR(file);
+ }
+
+ rc = kernel_read_file(file, 0, &data, INT_MAX, NULL,
+ READING_DIGEST_LIST);
+ if (rc < 0) {
+ pr_err("unable to read file: %s (%d)", path, rc);
+ goto out;
+ }
+
+ size = rc;
+
+ snprintf(event_name, sizeof(event_name), "%s_file_%s",
+ op == DIGEST_LIST_ADD ? "add" : "del",
+ file_dentry(file)->d_name.name);
+
+ rc = ima_measure_critical_data("diglim", event_name, data, size, false,
+ digest, sizeof(digest));
+ if (rc < 0 && rc != -EEXIST)
+ goto out_vfree;
+
+ algo = ima_get_current_hash_algo();
+
+ if (!rc || rc == -EEXIST)
+ actions |= (1 << COMPACT_ACTION_IMA_MEASURED);
+
+ rc = digest_list_parse(size, data, op, actions, digest, algo, "");
+ if (rc < 0)
+ pr_err("unable to upload digest list %s (%d)\n", path, rc);
+out_vfree:
+ vfree(data);
+out:
+ fput(file);
+
+ if (rc < 0)
+ return rc;
+
+ return pathlen;
+}
+
+/*
+ * digest_list_write: write the digest list path or the digest list itself
+ */
+static ssize_t digest_list_write(struct file *file, const char __user *buf,
+ size_t datalen, loff_t *ppos)
+{
+ char *data;
+ ssize_t result;
+ enum ops op = DIGEST_LIST_ADD;
+ struct dentry *dentry = file_dentry(file);
+ u8 digest[IMA_MAX_DIGEST_SIZE];
+ char event_name[NAME_MAX + 11 + 1];
+ enum hash_algo algo;
+ u8 actions = 0;
+
+ /* No partial writes. */
+ result = -EINVAL;
+ if (*ppos != 0)
+ goto out;
+
+ result = -EFBIG;
+ if (datalen > MAX_DIGEST_LIST_SIZE)
+ goto out;
+
+ data = memdup_user_nul(buf, datalen);
+ if (IS_ERR(data)) {
+ result = PTR_ERR(data);
+ goto out;
+ }
+
+ if (dentry == digest_list_del_dentry)
+ op = DIGEST_LIST_DEL;
+
+ result = -EPERM;
+
+ if (data[0] == '/') {
+ result = digest_list_read(data, op);
+ } else {
+ snprintf(event_name, sizeof(event_name), "%s_buffer_%s",
+ op == DIGEST_LIST_ADD ? "add" : "del", digest_label);
+
+ result = ima_measure_critical_data("diglim", event_name, data,
+ datalen, false, digest,
+ sizeof(digest));
+ if (result < 0 && result != -EEXIST) {
+ pr_err("failed to measure buffer digest (%ld)\n",
+ result);
+ goto out_kfree;
+ }
+
+ algo = ima_get_current_hash_algo();
+
+ if (!result || result == -EEXIST)
+ actions |= (1 << COMPACT_ACTION_IMA_MEASURED);
+
+ result = digest_list_parse(datalen, data, op, actions, digest,
+ algo, "");
+ if (result != datalen) {
+ pr_err("unable to upload generated digest list\n");
+ result = -EINVAL;
+ }
+ }
+out_kfree:
+ kfree(data);
+out:
+ return result;
+}
+
+static unsigned long flags;
+
+/*
+ * digest_list_open: sequentialize access to the add/del files
+ */
+static int digest_list_open(struct inode *inode, struct file *filp)
+{
+ if ((filp->f_flags & O_ACCMODE) != O_WRONLY)
+ return -EACCES;
+
+ if (test_and_set_bit(0, &flags))
+ return -EBUSY;
+
+ return 0;
+}
+
+/*
+ * digest_list_release - release the add/del files
+ */
+static int digest_list_release(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &flags);
+ return 0;
+}
+
+static const struct file_operations digest_list_upload_ops = {
+ .open = digest_list_open,
+ .write = digest_list_write,
+ .read = seq_read,
+ .release = digest_list_release,
+ .llseek = generic_file_llseek,
+};
+
+static int __init diglim_fs_init(void)
+{
+ diglim_dir = securityfs_create_dir("diglim", integrity_dir);
+ if (IS_ERR(diglim_dir))
+ return -1;
+
+ digest_list_add_dentry = securityfs_create_file("digest_list_add", 0200,
+ diglim_dir, NULL,
+ &digest_list_upload_ops);
+ if (IS_ERR(digest_list_add_dentry))
+ goto out;
+
+ digest_list_del_dentry = securityfs_create_file("digest_list_del", 0200,
+ diglim_dir, NULL,
+ &digest_list_upload_ops);
+ if (IS_ERR(digest_list_del_dentry))
+ goto out;
+
+ return 0;
+out:
+ securityfs_remove(digest_list_del_dentry);
+ securityfs_remove(digest_list_add_dentry);
+ securityfs_remove(diglim_dir);
+ return -1;
+}
+
+late_initcall(diglim_fs_init);
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 547425c20e11..ac45e1599c2d 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -6,6 +6,9 @@
* Mimi Zohar <zohar@us.ibm.com>
*/
+#ifndef __INTEGRITY_H
+#define __INTEGRITY_H
+
#ifdef pr_fmt
#undef pr_fmt
#endif
@@ -283,3 +286,4 @@ static inline void __init add_to_platform_keyring(const char *source,
{
}
#endif
+#endif /*__INTEGRITY_H*/
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 05/12] diglim: Parser
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the necessary functions to parse a digest list and to execute the
requested operation.
The main function is digest_list_parse(), which coordinates the various
steps required to add or delete a digest list, and has the logic to roll
back when one of the steps fails.
A more detailed description about the steps can be found in
Documentation/security/diglim/implementation.rst
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
.../security/diglim/implementation.rst | 35 +++
MAINTAINERS | 1 +
security/integrity/diglim/Makefile | 2 +-
security/integrity/diglim/diglim.h | 3 +
security/integrity/diglim/parser.c | 274 ++++++++++++++++++
5 files changed, 314 insertions(+), 1 deletion(-)
create mode 100644 security/integrity/diglim/parser.c
diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst
index 54af23b2f5f1..9d679567a037 100644
--- a/Documentation/security/diglim/implementation.rst
+++ b/Documentation/security/diglim/implementation.rst
@@ -209,3 +209,38 @@ This section introduces the methods requires to manage the three objects
defined.
.. kernel-doc:: security/integrity/diglim/methods.c
+
+
+Parser
+------
+
+This section introduces the necessary functions to parse a digest list and
+to execute the requested operation.
+
+.. kernel-doc:: security/integrity/diglim/parser.c
+
+The main function is digest_list_parse(), which coordinates the various
+steps required to add or delete a digest list, and has the logic to roll
+back when one of the steps fails.
+
+#. Calls digest_list_validate() to validate the passed buffer containing
+ the digest list to ensure that the format is correct.
+
+#. Calls get_digest_list() to create a new digest_list_item for the add
+ operation, or to retrieve the existing one for the delete operation.
+ get_digest_list() refuses to add digest lists that were previously
+ added and to delete digest lists that weren't previously added. Also,
+ get_digest_list() refuses to delete digest lists if there are actions
+ done at addition time that are not currently being performed (it would
+ guarantee that also deletion is notified to remote verifiers).
+
+#. Calls _digest_list_parse() which takes the created/retrieved
+ struct digest_list_item and adds or delete the digests included in the
+ digest list.
+
+#. If an error occurred, performs a rollback to the previous state, by
+ calling _digest_list_parse() with the opposite operation and the buffer
+ size at the time the error occurred.
+
+#. digest_list_parse() deletes the struct digest_list_item on unsuccessful
+ add or successful delete.
diff --git a/MAINTAINERS b/MAINTAINERS
index 9e085a36654a..77c3613c600a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5465,6 +5465,7 @@ F: include/linux/diglim.h
F: include/uapi/linux/diglim.h
F: security/integrity/diglim/diglim.h
F: security/integrity/diglim/methods.c
+F: security/integrity/diglim/parser.c
DIOLAN U2C-12 I2C DRIVER
M: Guenter Roeck <linux@roeck-us.net>
diff --git a/security/integrity/diglim/Makefile b/security/integrity/diglim/Makefile
index b761ed8cfb3e..34e4e154fff3 100644
--- a/security/integrity/diglim/Makefile
+++ b/security/integrity/diglim/Makefile
@@ -5,4 +5,4 @@
obj-$(CONFIG_DIGLIM) += diglim.o
-diglim-y := methods.o
+diglim-y := methods.o parser.o
diff --git a/security/integrity/diglim/diglim.h b/security/integrity/diglim/diglim.h
index 25851e7d4906..3adc218a0325 100644
--- a/security/integrity/diglim/diglim.h
+++ b/security/integrity/diglim/diglim.h
@@ -149,4 +149,7 @@ struct digest_item *digest_list_add(u8 *digest, enum hash_algo algo,
const char *label);
void digest_list_del(u8 *digest, enum hash_algo algo, u8 actions,
struct digest_list_item *digest_list);
+
+int digest_list_parse(loff_t size, void *buf, enum ops op, u8 actions,
+ u8 *digest, enum hash_algo algo, const char *label);
#endif /*__DIGLIM_INTERNAL_H*/
diff --git a/security/integrity/diglim/parser.c b/security/integrity/diglim/parser.c
new file mode 100644
index 000000000000..89a48945b460
--- /dev/null
+++ b/security/integrity/diglim/parser.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Functions to parse digest lists.
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+
+#include "diglim.h"
+#include "../integrity.h"
+
+/**
+ * digest_list_validate - validate format of digest list
+ * @size: buffer size
+ * @buf: buffer containing the digest list
+ *
+ * This function validates the format of the passed digest list.
+ *
+ * Return: 0 if the digest list was successfully validated, -EINVAL otherwise.
+ */
+static int digest_list_validate(loff_t size, void *buf)
+{
+ void *bufp = buf, *bufendp = buf + size;
+ struct compact_list_hdr *hdr;
+ size_t digest_len;
+
+ while (bufp < bufendp) {
+ if (bufp + sizeof(*hdr) > bufendp) {
+ pr_err("invalid data\n");
+ return -EINVAL;
+ }
+
+ hdr = bufp;
+
+ if (hdr->version != 1) {
+ pr_err("unsupported version\n");
+ return -EINVAL;
+ }
+
+ if (hdr->_reserved != 0) {
+ pr_err("unexpected value for _reserved field\n");
+ return -EINVAL;
+ }
+
+ hdr->type = le16_to_cpu(hdr->type);
+ hdr->modifiers = le16_to_cpu(hdr->modifiers);
+ hdr->algo = le16_to_cpu(hdr->algo);
+ hdr->count = le32_to_cpu(hdr->count);
+ hdr->datalen = le32_to_cpu(hdr->datalen);
+
+ if (hdr->algo >= HASH_ALGO__LAST) {
+ pr_err("invalid hash algorithm\n");
+ return -EINVAL;
+ }
+
+ digest_len = hash_digest_size[hdr->algo];
+
+ if (hdr->type >= COMPACT__LAST ||
+ hdr->type == COMPACT_DIGEST_LIST) {
+ pr_err("invalid type %d\n", hdr->type);
+ return -EINVAL;
+ }
+
+ bufp += sizeof(*hdr);
+
+ if (hdr->datalen != hdr->count * digest_len ||
+ bufp + hdr->datalen > bufendp) {
+ pr_err("invalid data\n");
+ return -EINVAL;
+ }
+
+ bufp += hdr->count * digest_len;
+ }
+
+ return 0;
+}
+
+/**
+ * _digest_list_parse - parse digest list and add/delete digests
+ * @size: buffer size
+ * @buf: buffer containing the digest list
+ * @op: operation to be performed
+ * @digest_list: digest list digests being added/deleted belong to
+ *
+ * This function parses the digest list and adds or delete the digests in the
+ * found digest blocks.
+ *
+ * Return: the buffer size if all digests were successfully added or deleted,
+ * the size of the already parsed buffer on error.
+ */
+static int _digest_list_parse(loff_t size, void *buf, enum ops op,
+ struct digest_list_item *digest_list)
+{
+ void *bufp = buf, *bufendp = buf + size;
+ struct compact_list_hdr *hdr;
+ struct digest_item *d = ERR_PTR(-EINVAL);
+ size_t digest_len;
+ int i;
+
+ while (bufp < bufendp) {
+ if (bufp + sizeof(*hdr) > bufendp)
+ break;
+
+ hdr = bufp;
+ bufp += sizeof(*hdr);
+
+ digest_len = hash_digest_size[hdr->algo];
+
+ for (i = 0; i < hdr->count && bufp + digest_len <= bufendp;
+ i++, bufp += digest_len) {
+ switch (op) {
+ case DIGEST_LIST_ADD:
+ d = digest_add(bufp, hdr->algo, hdr->type,
+ digest_list, bufp - buf,
+ (void *)hdr - buf);
+ if (IS_ERR(d)) {
+ pr_err(
+ "failed to add a digest from %s\n",
+ digest_list->label);
+ goto out;
+ }
+
+ break;
+ case DIGEST_LIST_DEL:
+ digest_del(bufp, hdr->algo, hdr->type,
+ digest_list, bufp - buf,
+ (void *)hdr - buf);
+ break;
+ default:
+ break;
+ }
+ }
+ }
+out:
+ return bufp - buf;
+}
+
+/**
+ * get_digest_list - get the digest list extracted digests will be associated to
+ * @size: buffer size
+ * @buf: buffer containing the digest list
+ * @op: digest list operation
+ * @actions: actions performed on the digest list being processed
+ * @digest: digest of the digest list
+ * @algo: digest algorithm
+ * @label: label to identify the digest list (e.g. file name)
+ *
+ * This function retrieves the digest list item for the passed digest and
+ * algorithm. If it is not found at addition time, this function creates a new
+ * one.
+ *
+ * This function prevents the imbalance of digests (references left after
+ * delete) by ensuring that only digest lists that were previously added can be
+ * deleted.
+ *
+ * This function also ensures that the actions done at the time of addition are
+ * also performed at the time of deletion (it would guarantee that also deletion
+ * is notified to remote verifiers).
+ *
+ * Return: the retrieved/created digest list item on success, an error pointer
+ * otherwise.
+ */
+static struct digest_list_item *get_digest_list(loff_t size, void *buf,
+ enum ops op, u8 actions,
+ u8 *digest, enum hash_algo algo,
+ const char *label)
+{
+ struct digest_item *d;
+ struct digest_list_item *digest_list;
+ int digest_len = hash_digest_size[algo];
+
+ switch (op) {
+ case DIGEST_LIST_ADD:
+ /* Add digest list to be associated to each digest. */
+ d = digest_list_add(digest, algo, size, buf, actions, label);
+ if (IS_ERR(d))
+ return (void *)d;
+
+ digest_list = list_first_entry(&d->refs,
+ struct digest_list_item_ref, list)->digest_list;
+ break;
+ case DIGEST_LIST_DEL:
+ /* Lookup digest list to delete the references. */
+ d = __digest_lookup(digest, algo, COMPACT_DIGEST_LIST, NULL,
+ NULL);
+ if (!d) {
+ print_hex_dump(KERN_ERR,
+ "digest list digest not found: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ return ERR_PTR(-ENOENT);
+ }
+
+ digest_list = list_first_entry(&d->refs,
+ struct digest_list_item_ref, list)->digest_list;
+
+ /*
+ * Reject deletion if there are actions done at addition time
+ * that are currently not being performed.
+ */
+ if ((digest_list->actions & actions) != digest_list->actions) {
+ pr_err("missing actions, add: %d, del: %d\n",
+ digest_list->actions, actions);
+ return ERR_PTR(-EPERM);
+ }
+
+ break;
+ default:
+ return ERR_PTR(-EINVAL);
+ }
+
+ return digest_list;
+}
+
+/**
+ * digest_list_parse - parse a digest list
+ * @size: buffer size
+ * @buf: buffer containing the digest list
+ * @op: digest list operation
+ * @actions: actions performed on the digest list being processed
+ * @digest: digest of the digest list
+ * @algo: digest algorithm
+ * @label: label to identify the digest list (e.g. file name)
+ *
+ * This function parses the passed digest list and executed the requested
+ * operation. If the operation cannot be successfully executed, this function
+ * performs a rollback to the previous state.
+ *
+ * Return: the buffer size on success, a negative value otherwise.
+ */
+int digest_list_parse(loff_t size, void *buf, enum ops op, u8 actions,
+ u8 *digest, enum hash_algo algo, const char *label)
+{
+ struct digest_list_item *digest_list;
+ enum ops rollback_op = (op == DIGEST_LIST_ADD) ?
+ DIGEST_LIST_DEL : DIGEST_LIST_ADD;
+ int ret, rollback_size;
+
+ ret = digest_list_validate(size, buf);
+ if (ret < 0)
+ return ret;
+
+ digest_list = get_digest_list(size, buf, op, actions, digest, algo,
+ label);
+ if (IS_ERR(digest_list))
+ return PTR_ERR(digest_list);
+
+ ret = _digest_list_parse(size, buf, op, digest_list);
+ if (ret < 0)
+ goto out;
+
+ if (ret != size) {
+ rollback_size = ret;
+
+ ret = _digest_list_parse(rollback_size, buf, rollback_op,
+ digest_list);
+ if (ret != rollback_size)
+ pr_err("rollback failed\n");
+
+ ret = -EINVAL;
+ }
+out:
+ /* Delete digest list on unsuccessful add or successful delete. */
+ if ((op == DIGEST_LIST_ADD && ret < 0) ||
+ (op == DIGEST_LIST_DEL && ret == size))
+ digest_list_del(digest, algo, actions, digest_list);
+
+ return ret;
+}
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 12/12] diglim: Tests
From: Roberto Sassu @ 2021-07-26 16:37 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce a number of tests to ensure that DIGLIM works as expected:
- digest_list_add_del_test_file_upload;
- digest_list_add_del_test_file_upload_fault;
- digest_list_add_del_test_buffer_upload;
- digest_list_add_del_test_buffer_upload_fault;
- digest_list_fuzzing_test;
- digest_list_add_del_test_file_upload_measured;
- digest_list_check_measurement_list_test_file_upload;
- digest_list_check_measurement_list_test_buffer_upload.
The tests are in tools/testing/selftests/diglim/selftest.c.
A description of the tests can be found in
Documentation/security/diglim/tests.rst.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
Documentation/security/diglim/index.rst | 1 +
Documentation/security/diglim/tests.rst | 66 +
MAINTAINERS | 2 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/diglim/Makefile | 19 +
tools/testing/selftests/diglim/common.c | 115 ++
tools/testing/selftests/diglim/common.h | 31 +
tools/testing/selftests/diglim/config | 3 +
tools/testing/selftests/diglim/selftest.c | 1382 +++++++++++++++++++++
9 files changed, 1620 insertions(+)
create mode 100644 Documentation/security/diglim/tests.rst
create mode 100644 tools/testing/selftests/diglim/Makefile
create mode 100644 tools/testing/selftests/diglim/common.c
create mode 100644 tools/testing/selftests/diglim/common.h
create mode 100644 tools/testing/selftests/diglim/config
create mode 100644 tools/testing/selftests/diglim/selftest.c
diff --git a/Documentation/security/diglim/index.rst b/Documentation/security/diglim/index.rst
index 0f28c5ad71c0..d4ba4ce50a59 100644
--- a/Documentation/security/diglim/index.rst
+++ b/Documentation/security/diglim/index.rst
@@ -11,3 +11,4 @@ Digest Lists Integrity Module (DIGLIM)
architecture
implementation
remote_attestation
+ tests
diff --git a/Documentation/security/diglim/tests.rst b/Documentation/security/diglim/tests.rst
new file mode 100644
index 000000000000..d58ddbaeeb55
--- /dev/null
+++ b/Documentation/security/diglim/tests.rst
@@ -0,0 +1,66 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Testing
+=======
+
+This section introduces a number of tests to ensure that DIGLIM works as
+expected:
+
+- ``digest_list_add_del_test_file_upload``;
+- ``digest_list_add_del_test_file_upload_fault``;
+- ``digest_list_add_del_test_buffer_upload``;
+- ``digest_list_add_del_test_buffer_upload_fault``;
+- ``digest_list_fuzzing_test``;
+- ``digest_list_add_del_test_file_upload_measured``;
+- ``digest_list_check_measurement_list_test_file_upload``;
+- ``digest_list_check_measurement_list_test_buffer_upload``.
+
+The tests are in ``tools/testing/selftests/diglim/selftest.c``.
+
+The first four tests randomly perform add, delete and query of digest
+lists. They internally keep track at any time of the digest lists that are
+currently uploaded to the kernel.
+
+Also, digest lists are generated randomly by selecting an arbitrary digest
+algorithm and an arbitrary number of digests. To ensure a good number of
+collisions, digests are a sequence of zeros, except for the first four
+bytes that are set with a random number within a defined range.
+
+When a query operation is selected, a digest is chosen by getting another
+random number within the same range. Then, the tests count how many times
+the digest is found in the internally stored digest lists and in the query
+result obtained from the kernel. The tests are successful if the obtained
+numbers are the same.
+
+The ``file_upload`` variant creates a temporary file from a generated
+digest list and sends its path to the kernel, so that the file is uploaded.
+The ``buffer_upload`` variant directly sends the digest list buffer to the
+kernel (it will be done by the user space parser after it converts a digest
+list not in the compact format).
+
+The ``fault`` variant performs the test by enabling the ad-hoc fault
+injection mechanism in the kernel (accessible through
+``<debugfs>/fail_diglim``). The fault injection mechanism randomly injects
+errors during the addition and deletion of digest lists. When an error
+occurs, the rollback mechanism performs the reverse operation until the
+point the error occurred, so that the kernel is left in the same state as
+when the requested operation began. Since the kernel returns the error to
+user space, the tests also know that the operation didn't succeed and
+behave accordingly (they also revert the internal state).
+
+The fuzzing test simply sends randomly generated digest lists to the
+kernel, to ensure that the parser is robust enough to handle malformed
+data.
+
+The ``measured`` variant of the ``digest_list_add_del_test`` series checks
+whether the digest lists actions are properly set after adding an IMA rule
+to measure the digest lists.
+
+The ``digest_list_check_measurement_list_test`` tests verify the remote
+attestation functionality. They verify whether IMA creates a measurement
+entry for each addition and deletion of a digest list, and that the
+deletion is forbidden if IMA created a measurement entry only for the
+addition.
+
+The ``file_upload`` variant uploads a file, while the ``buffer_upload``
+variant uploads a buffer.
diff --git a/MAINTAINERS b/MAINTAINERS
index a7c502685109..e63061e63363 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5462,12 +5462,14 @@ F: Documentation/security/diglim/implementation.rst
F: Documentation/security/diglim/index.rst
F: Documentation/security/diglim/introduction.rst
F: Documentation/security/diglim/remote_attestation.rst
+F: Documentation/security/diglim/tests.rst
F: include/linux/diglim.h
F: include/uapi/linux/diglim.h
F: security/integrity/diglim/diglim.h
F: security/integrity/diglim/fs.c
F: security/integrity/diglim/methods.c
F: security/integrity/diglim/parser.c
+F: tools/testing/selftests/diglim/
DIOLAN U2C-12 I2C DRIVER
M: Guenter Roeck <linux@roeck-us.net>
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index fb010a35d61a..37460b308e07 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -8,6 +8,7 @@ TARGETS += clone3
TARGETS += core
TARGETS += cpufreq
TARGETS += cpu-hotplug
+TARGETS += diglim
TARGETS += drivers/dma-buf
TARGETS += efivarfs
TARGETS += exec
diff --git a/tools/testing/selftests/diglim/Makefile b/tools/testing/selftests/diglim/Makefile
new file mode 100644
index 000000000000..100c219955d7
--- /dev/null
+++ b/tools/testing/selftests/diglim/Makefile
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0
+LDFLAGS += -lcrypto
+
+CFLAGS += -O2 -Wall -Wl,-no-as-needed -g -I./ -I../../../../usr/include/ \
+ -L$(OUTPUT) -Wl,-rpath=./ -ggdb
+LDLIBS += -lpthread
+
+OVERRIDE_TARGETS = 1
+
+TEST_GEN_PROGS = selftest
+TEST_GEN_PROGS_EXTENDED = libcommon.so
+
+include ../lib.mk
+
+$(OUTPUT)/libcommon.so: common.c
+ $(CC) $(CFLAGS) -shared -fPIC $< $(LDLIBS) -o $@
+
+$(OUTPUT)/selftest: selftest.c $(TEST_GEN_PROGS_EXTENDED)
+ $(CC) $(CFLAGS) $< -o $@ $(LDFLAGS) -lcommon
diff --git a/tools/testing/selftests/diglim/common.c b/tools/testing/selftests/diglim/common.c
new file mode 100644
index 000000000000..88ff48fed308
--- /dev/null
+++ b/tools/testing/selftests/diglim/common.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Common functions.
+ */
+
+#include <sys/random.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <malloc.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/types.h>
+#include <linux/hash_info.h>
+
+#include "common.h"
+
+int write_buffer(char *path, char *buffer, size_t buffer_len, int uid)
+{
+ ssize_t to_write = buffer_len, written = 0;
+ int ret = 0, ret_seteuid, fd, cur_uid = geteuid();
+
+ fd = open(path, O_WRONLY);
+ if (fd < 0)
+ return -errno;
+
+ if (uid >= 0) {
+ ret_seteuid = seteuid(uid);
+ if (ret_seteuid < 0)
+ return ret_seteuid;
+ }
+
+ while (to_write) {
+ written = write(fd, buffer + buffer_len - to_write, to_write);
+ if (written <= 0) {
+ ret = -errno;
+ break;
+ }
+
+ to_write -= written;
+ }
+
+ if (uid >= 0) {
+ ret_seteuid = seteuid(cur_uid);
+ if (ret_seteuid < 0)
+ return ret_seteuid;
+ }
+
+ close(fd);
+ return ret;
+}
+
+int read_buffer(char *path, char **buffer, size_t *buffer_len, bool alloc,
+ bool is_char)
+{
+ ssize_t len = 0, read_len;
+ int ret = 0, fd;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ if (alloc) {
+ *buffer = NULL;
+ *buffer_len = 0;
+ }
+
+ while (1) {
+ if (alloc) {
+ if (*buffer_len == len) {
+ *buffer_len += BUFFER_SIZE;
+ *buffer = realloc(*buffer, *buffer_len + 1);
+ if (!*buffer) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+ }
+
+ read_len = read(fd, *buffer + len, *buffer_len - len);
+ if (read_len < 0) {
+ ret = -errno;
+ goto out;
+ }
+
+ if (!read_len)
+ break;
+
+ len += read_len;
+ }
+
+ *buffer_len = len;
+ if (is_char)
+ (*buffer)[(*buffer_len)++] = '\0';
+out:
+ close(fd);
+ if (ret < 0) {
+ if (alloc) {
+ free(*buffer);
+ *buffer = NULL;
+ }
+ }
+
+ return ret;
+}
diff --git a/tools/testing/selftests/diglim/common.h b/tools/testing/selftests/diglim/common.h
new file mode 100644
index 000000000000..d3e5808c06e8
--- /dev/null
+++ b/tools/testing/selftests/diglim/common.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Header of common.c
+ */
+
+#include <sys/random.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <malloc.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/types.h>
+#include <linux/hash_info.h>
+
+#define BUFFER_SIZE 1024
+
+int write_buffer(char *path, char *buffer, size_t buffer_len, int uid);
+int read_buffer(char *path, char **buffer, size_t *buffer_len, bool alloc,
+ bool is_char);
diff --git a/tools/testing/selftests/diglim/config b/tools/testing/selftests/diglim/config
new file mode 100644
index 000000000000..faafc742974c
--- /dev/null
+++ b/tools/testing/selftests/diglim/config
@@ -0,0 +1,3 @@
+CONFIG_DIGEST_LISTS=y
+CONFIG_FAULT_INJECTION=y
+CONFIG_FAULT_INJECTION_DEBUG_FS=y
diff --git a/tools/testing/selftests/diglim/selftest.c b/tools/testing/selftests/diglim/selftest.c
new file mode 100644
index 000000000000..efcd83409b39
--- /dev/null
+++ b/tools/testing/selftests/diglim/selftest.c
@@ -0,0 +1,1382 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Functions to test DIGLIM.
+ */
+
+#include <sys/random.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <malloc.h>
+#include <unistd.h>
+#include <string.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/types.h>
+#include <linux/hash_info.h>
+#include <linux/diglim.h>
+
+#include <openssl/evp.h>
+
+#include "common.h"
+#include "../kselftest_harness.h"
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef uint32_t u32;
+typedef uint64_t u64;
+
+#define MD5_DIGEST_SIZE 16
+#define SHA1_DIGEST_SIZE 20
+#define RMD160_DIGEST_SIZE 20
+#define SHA256_DIGEST_SIZE 32
+#define SHA384_DIGEST_SIZE 48
+#define SHA512_DIGEST_SIZE 64
+#define SHA224_DIGEST_SIZE 28
+#define RMD128_DIGEST_SIZE 16
+#define RMD256_DIGEST_SIZE 32
+#define RMD320_DIGEST_SIZE 40
+#define WP256_DIGEST_SIZE 32
+#define WP384_DIGEST_SIZE 48
+#define WP512_DIGEST_SIZE 64
+#define TGR128_DIGEST_SIZE 16
+#define TGR160_DIGEST_SIZE 20
+#define TGR192_DIGEST_SIZE 24
+#define SM3256_DIGEST_SIZE 32
+#define STREEBOG256_DIGEST_SIZE 32
+#define STREEBOG512_DIGEST_SIZE 64
+
+#define DIGEST_LIST_PATH_TEMPLATE "/tmp/digest_list.XXXXXX"
+
+#define INTEGRITY_DIR "/sys/kernel/security/integrity"
+
+#define DIGEST_LIST_DIR INTEGRITY_DIR "/diglim"
+#define DIGEST_QUERY_PATH DIGEST_LIST_DIR "/digest_query"
+#define DIGEST_LABEL_PATH DIGEST_LIST_DIR "/digest_label"
+#define DIGEST_LIST_ADD_PATH DIGEST_LIST_DIR "/digest_list_add"
+#define DIGEST_LIST_DEL_PATH DIGEST_LIST_DIR "/digest_list_del"
+#define DIGEST_LISTS_LOADED_PATH DIGEST_LIST_DIR "/digest_lists_loaded"
+#define DIGESTS_COUNT DIGEST_LIST_DIR "/digests_count"
+
+#define IMA_POLICY_PATH INTEGRITY_DIR "/ima/policy"
+#define IMA_MEASUREMENTS_PATH INTEGRITY_DIR "/ima/ascii_runtime_measurements"
+
+#define DIGEST_LIST_DEBUGFS_DIR "/sys/kernel/debug/fail_diglim"
+#define DIGEST_LIST_DEBUGFS_TASK_FILTER DIGEST_LIST_DEBUGFS_DIR "/task-filter"
+#define DIGEST_LIST_DEBUGFS_PROBABILITY DIGEST_LIST_DEBUGFS_DIR "/probability"
+#define DIGEST_LIST_DEBUGFS_TIMES DIGEST_LIST_DEBUGFS_DIR "/times"
+#define DIGEST_LIST_DEBUGFS_VERBOSE DIGEST_LIST_DEBUGFS_DIR "/verbose"
+#define PROCFS_SELF_FAULT "/proc/self/make-it-fail"
+
+#define MAX_LINE_LENGTH 512
+#define LABEL_LEN 32
+#define MAX_DIGEST_COUNT 100
+#define MAX_DIGEST_LISTS 100
+#define MAX_DIGEST_BLOCKS 10
+#define MAX_DIGEST_VALUE 10
+#define MAX_SEARCH_ATTEMPTS 10
+#define NUM_QUERIES 1000
+#define MAX_DIGEST_LIST_SIZE 10000
+#define NUM_ITERATIONS 100000
+
+enum upload_types { UPLOAD_FILE, UPLOAD_BUFFER };
+
+const char *const hash_algo_name[HASH_ALGO__LAST] = {
+ [HASH_ALGO_MD4] = "md4",
+ [HASH_ALGO_MD5] = "md5",
+ [HASH_ALGO_SHA1] = "sha1",
+ [HASH_ALGO_RIPE_MD_160] = "rmd160",
+ [HASH_ALGO_SHA256] = "sha256",
+ [HASH_ALGO_SHA384] = "sha384",
+ [HASH_ALGO_SHA512] = "sha512",
+ [HASH_ALGO_SHA224] = "sha224",
+ [HASH_ALGO_RIPE_MD_128] = "rmd128",
+ [HASH_ALGO_RIPE_MD_256] = "rmd256",
+ [HASH_ALGO_RIPE_MD_320] = "rmd320",
+ [HASH_ALGO_WP_256] = "wp256",
+ [HASH_ALGO_WP_384] = "wp384",
+ [HASH_ALGO_WP_512] = "wp512",
+ [HASH_ALGO_TGR_128] = "tgr128",
+ [HASH_ALGO_TGR_160] = "tgr160",
+ [HASH_ALGO_TGR_192] = "tgr192",
+ [HASH_ALGO_SM3_256] = "sm3",
+ [HASH_ALGO_STREEBOG_256] = "streebog256",
+ [HASH_ALGO_STREEBOG_512] = "streebog512",
+};
+
+const int hash_digest_size[HASH_ALGO__LAST] = {
+ [HASH_ALGO_MD4] = MD5_DIGEST_SIZE,
+ [HASH_ALGO_MD5] = MD5_DIGEST_SIZE,
+ [HASH_ALGO_SHA1] = SHA1_DIGEST_SIZE,
+ [HASH_ALGO_RIPE_MD_160] = RMD160_DIGEST_SIZE,
+ [HASH_ALGO_SHA256] = SHA256_DIGEST_SIZE,
+ [HASH_ALGO_SHA384] = SHA384_DIGEST_SIZE,
+ [HASH_ALGO_SHA512] = SHA512_DIGEST_SIZE,
+ [HASH_ALGO_SHA224] = SHA224_DIGEST_SIZE,
+ [HASH_ALGO_RIPE_MD_128] = RMD128_DIGEST_SIZE,
+ [HASH_ALGO_RIPE_MD_256] = RMD256_DIGEST_SIZE,
+ [HASH_ALGO_RIPE_MD_320] = RMD320_DIGEST_SIZE,
+ [HASH_ALGO_WP_256] = WP256_DIGEST_SIZE,
+ [HASH_ALGO_WP_384] = WP384_DIGEST_SIZE,
+ [HASH_ALGO_WP_512] = WP512_DIGEST_SIZE,
+ [HASH_ALGO_TGR_128] = TGR128_DIGEST_SIZE,
+ [HASH_ALGO_TGR_160] = TGR160_DIGEST_SIZE,
+ [HASH_ALGO_TGR_192] = TGR192_DIGEST_SIZE,
+ [HASH_ALGO_SM3_256] = SM3256_DIGEST_SIZE,
+ [HASH_ALGO_STREEBOG_256] = STREEBOG256_DIGEST_SIZE,
+ [HASH_ALGO_STREEBOG_512] = STREEBOG512_DIGEST_SIZE,
+};
+
+struct digest_list_item {
+ unsigned long long size;
+ u8 *buf;
+ u8 actions;
+ char digest_str[64 * 2 + 1];
+ enum hash_algo algo;
+ char filename_suffix[6 + 1];
+};
+
+static const char hex_asc[] = "0123456789abcdef";
+
+#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
+
+static inline char *hex_byte_pack(char *buf, unsigned char byte)
+{
+ *buf++ = hex_asc_hi(byte);
+ *buf++ = hex_asc_lo(byte);
+ return buf;
+}
+
+/* from lib/hexdump.c (Linux kernel) */
+static int hex_to_bin(char ch)
+{
+ if ((ch >= '0') && (ch <= '9'))
+ return ch - '0';
+ ch = tolower(ch);
+ if ((ch >= 'a') && (ch <= 'f'))
+ return ch - 'a' + 10;
+ return -1;
+}
+
+int _hex2bin(unsigned char *dst, const char *src, size_t count)
+{
+ while (count--) {
+ int hi = hex_to_bin(*src++);
+ int lo = hex_to_bin(*src++);
+
+ if ((hi < 0) || (lo < 0))
+ return -1;
+
+ *dst++ = (hi << 4) | lo;
+ }
+ return 0;
+}
+
+char *_bin2hex(char *dst, const void *src, size_t count)
+{
+ const unsigned char *_src = src;
+
+ while (count--)
+ dst = hex_byte_pack(dst, *_src++);
+ return dst;
+}
+
+u32 num_max_digest_lists = MAX_DIGEST_LISTS;
+u32 digest_lists_pos;
+struct digest_list_item *digest_lists[MAX_DIGEST_LISTS];
+
+enum hash_algo ima_hash_algo = HASH_ALGO__LAST;
+
+static enum hash_algo get_ima_hash_algo(void)
+{
+ char *measurement_list, *measurement_list_ptr;
+ size_t measurement_list_len;
+ int ret, i = 0;
+
+ if (ima_hash_algo != HASH_ALGO__LAST)
+ return ima_hash_algo;
+
+ ret = read_buffer(IMA_MEASUREMENTS_PATH, &measurement_list,
+ &measurement_list_len, true, true);
+ if (ret < 0)
+ return HASH_ALGO_SHA256;
+
+ measurement_list_ptr = measurement_list;
+ while ((strsep(&measurement_list_ptr, " ")) && i++ < 2)
+ ;
+
+ for (i = 0; i < HASH_ALGO__LAST; i++) {
+ if (!strncmp(hash_algo_name[i], measurement_list_ptr,
+ strlen(hash_algo_name[i]))) {
+ ima_hash_algo = i;
+ break;
+ }
+ }
+
+ free(measurement_list);
+ return ima_hash_algo;
+}
+
+int calc_digest(u8 *digest, void *data, u64 len, enum hash_algo algo)
+{
+ EVP_MD_CTX *mdctx;
+ const EVP_MD *md;
+ int ret = -EINVAL;
+
+ OpenSSL_add_all_algorithms();
+
+ md = EVP_get_digestbyname(hash_algo_name[algo]);
+ if (!md)
+ goto out;
+
+ mdctx = EVP_MD_CTX_create();
+ if (!mdctx)
+ goto out;
+
+ if (EVP_DigestInit_ex(mdctx, md, NULL) != 1)
+ goto out_mdctx;
+
+ if (EVP_DigestUpdate(mdctx, data, len) != 1)
+ goto out_mdctx;
+
+ if (EVP_DigestFinal_ex(mdctx, digest, NULL) != 1)
+ goto out_mdctx;
+
+ ret = 0;
+out_mdctx:
+ EVP_MD_CTX_destroy(mdctx);
+out:
+ EVP_cleanup();
+ return ret;
+}
+
+int calc_file_digest(u8 *digest, char *path, enum hash_algo algo)
+{
+ void *data = MAP_FAILED;
+ struct stat st;
+ int fd, ret = 0;
+
+ if (stat(path, &st) == -1)
+ return -EACCES;
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ if (st.st_size) {
+ data = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ if (data == MAP_FAILED) {
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ ret = calc_digest(digest, data, st.st_size, algo);
+out:
+ if (data != MAP_FAILED)
+ munmap(data, st.st_size);
+
+ close(fd);
+ return ret;
+}
+
+static struct digest_list_item *digest_list_generate(void)
+{
+ struct digest_list_item *digest_list;
+ struct compact_list_hdr *hdr_array = NULL;
+ u8 *buf_ptr;
+ u32 num_digest_blocks = 0;
+ u8 digest[64];
+ int ret, i, j;
+
+ digest_list = calloc(1, sizeof(*digest_list));
+ if (!digest_list)
+ return NULL;
+
+ while (!num_digest_blocks) {
+ ret = getrandom(&num_digest_blocks,
+ sizeof(num_digest_blocks), 0);
+ if (ret < 0)
+ goto out;
+
+ num_digest_blocks = num_digest_blocks % MAX_DIGEST_BLOCKS;
+ }
+
+ hdr_array = calloc(num_digest_blocks, sizeof(*hdr_array));
+ if (!hdr_array)
+ goto out;
+
+ for (i = 0; i < num_digest_blocks; i++) {
+ ret = getrandom(&hdr_array[i], sizeof(hdr_array[i]), 0);
+ if (ret < 0)
+ goto out;
+
+ hdr_array[i].version = 1;
+ hdr_array[i]._reserved = 0;
+ /* COMPACT_DIGEST_LIST type is not allowed. */
+ hdr_array[i].type = hdr_array[i].type % (COMPACT__LAST - 1);
+ hdr_array[i].modifiers =
+ hdr_array[i].modifiers % (1 << COMPACT_MOD_IMMUTABLE) + 1;
+ hdr_array[i].algo = hdr_array[i].algo % HASH_ALGO_RIPE_MD_128;
+ hdr_array[i].count = hdr_array[i].count % MAX_DIGEST_COUNT;
+
+ while (!hdr_array[i].count) {
+ ret = getrandom(&hdr_array[i].count,
+ sizeof(hdr_array[i].count), 0);
+ if (ret < 0)
+ goto out;
+
+ hdr_array[i].count =
+ hdr_array[i].count % MAX_DIGEST_COUNT;
+ }
+
+ hdr_array[i].datalen =
+ hdr_array[i].count * hash_digest_size[hdr_array[i].algo];
+
+ digest_list->size += sizeof(*hdr_array) + hdr_array[i].datalen;
+ }
+
+ digest_list->buf = calloc(digest_list->size, sizeof(unsigned char));
+ if (!digest_list->buf) {
+ free(digest_list);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ buf_ptr = digest_list->buf;
+
+ for (i = 0; i < num_digest_blocks; i++) {
+ memcpy(buf_ptr, &hdr_array[i], sizeof(*hdr_array));
+ buf_ptr += sizeof(*hdr_array);
+
+ for (j = 0; j < hdr_array[i].count; j++) {
+ ret = getrandom(buf_ptr, sizeof(u32), 0);
+ if (ret < 0)
+ goto out;
+
+ *(u32 *)buf_ptr = *(u32 *)buf_ptr % MAX_DIGEST_VALUE;
+ buf_ptr += hash_digest_size[hdr_array[i].algo];
+ }
+ }
+
+ digest_list->algo = get_ima_hash_algo();
+ if (digest_list->algo == HASH_ALGO__LAST) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = calc_digest(digest, digest_list->buf, digest_list->size,
+ digest_list->algo);
+ if (ret < 0)
+ goto out;
+
+ _bin2hex(digest_list->digest_str, digest,
+ hash_digest_size[digest_list->algo]);
+
+ ret = 0;
+out:
+ if (ret < 0) {
+ free(digest_list->buf);
+ free(digest_list);
+ }
+
+ free(hdr_array);
+ return !ret ? digest_list : NULL;
+}
+
+static struct digest_list_item *digest_list_generate_random(void)
+{
+ struct digest_list_item *digest_list;
+ struct compact_list_hdr *hdr;
+ u32 size = 0;
+ u8 digest[64];
+ int ret;
+
+ digest_list = calloc(1, sizeof(*digest_list));
+ if (!digest_list)
+ return NULL;
+
+ while (!size) {
+ ret = getrandom(&size, sizeof(size), 0);
+ if (ret < 0)
+ goto out;
+
+ size = size % MAX_DIGEST_LIST_SIZE;
+ }
+
+ digest_list->size = size;
+ digest_list->buf = calloc(digest_list->size, sizeof(unsigned char));
+ if (!digest_list->buf) {
+ free(digest_list);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = getrandom(digest_list->buf, digest_list->size, 0);
+ if (ret < 0)
+ goto out;
+
+ hdr = (struct compact_list_hdr *)digest_list->buf;
+ hdr->version = 1;
+ hdr->_reserved = 0;
+ hdr->type = hdr->type % (COMPACT__LAST - 1);
+ hdr->algo = hdr->algo % HASH_ALGO__LAST;
+
+ digest_list->algo = get_ima_hash_algo();
+ if (digest_list->algo == HASH_ALGO__LAST) {
+ ret = -ENOENT;
+ goto out;
+ }
+
+ ret = calc_digest(digest, digest_list->buf, digest_list->size,
+ digest_list->algo);
+ if (ret < 0)
+ goto out;
+
+ _bin2hex(digest_list->digest_str, digest,
+ hash_digest_size[digest_list->algo]);
+
+ ret = 0;
+out:
+ if (ret < 0) {
+ free(digest_list->buf);
+ free(digest_list);
+ }
+
+ return !ret ? digest_list : NULL;
+}
+
+static int digest_list_upload(struct digest_list_item *digest_list, enum ops op,
+ enum upload_types upload_type, int uid)
+{
+ char path_template[] = DIGEST_LIST_PATH_TEMPLATE;
+ char *path_upload = DIGEST_LIST_ADD_PATH, *basename;
+ unsigned char *buffer = digest_list->buf;
+ size_t buffer_len = digest_list->size;
+ unsigned char rnd[3];
+ int ret = 0, fd;
+
+ if (op == DIGEST_LIST_ADD) {
+ if (upload_type == UPLOAD_FILE) {
+ fd = mkstemp(path_template);
+ if (fd < 0)
+ return -EPERM;
+
+ fchmod(fd, 0644);
+ close(fd);
+ ret = write_buffer(path_template,
+ (char *)digest_list->buf,
+ digest_list->size, -1);
+ if (ret < 0)
+ goto out;
+
+ buffer = (unsigned char *)path_template;
+ buffer_len = strlen(path_template);
+ } else {
+ ret = getrandom(rnd, sizeof(rnd), 0);
+ if (ret < 0)
+ goto out;
+
+ _bin2hex(path_template +
+ sizeof(DIGEST_LIST_PATH_TEMPLATE) - 7, rnd,
+ sizeof(rnd));
+ }
+
+ memcpy(digest_list->filename_suffix,
+ path_template + sizeof(DIGEST_LIST_PATH_TEMPLATE) - 7,
+ 6);
+ } else {
+ memcpy(path_template + sizeof(DIGEST_LIST_PATH_TEMPLATE) - 7,
+ digest_list->filename_suffix, 6);
+ path_upload = DIGEST_LIST_DEL_PATH;
+ if (upload_type == UPLOAD_FILE) {
+ buffer = (unsigned char *)path_template;
+ buffer_len = strlen(path_template);
+ }
+ }
+
+ if (upload_type == UPLOAD_BUFFER) {
+ basename = strrchr(path_template, '/') + 1;
+ ret = write_buffer(DIGEST_LABEL_PATH, basename,
+ strlen(basename), -1);
+ if (ret < 0)
+ goto out;
+ }
+
+ ret = write_buffer(path_upload, (char *)buffer, buffer_len, uid);
+out:
+ if ((op == DIGEST_LIST_ADD && ret < 0) ||
+ (op == DIGEST_LIST_DEL && !ret))
+ unlink(path_template);
+
+ return ret;
+}
+
+static int digest_list_check(struct digest_list_item *digest_list, enum ops op)
+{
+ char path[PATH_MAX];
+ u8 digest_list_buf[MAX_LINE_LENGTH];
+ char digest_list_info[MAX_LINE_LENGTH];
+ ssize_t size = digest_list->size;
+ struct compact_list_hdr *hdr;
+ struct stat st;
+ int ret = 0, i, fd, path_len, len, read_len;
+
+ path_len = snprintf(path, sizeof(path), "%s/%s-%s-digest_list.%s.ascii",
+ DIGEST_LISTS_LOADED_PATH,
+ hash_algo_name[digest_list->algo],
+ digest_list->digest_str,
+ digest_list->filename_suffix);
+
+ path[path_len - 6] = '\0';
+
+ if (op == DIGEST_LIST_DEL) {
+ if (stat(path, &st) != -1)
+ return -EEXIST;
+
+ path[path_len - 6] = '.';
+
+ if (stat(path, &st) != -1)
+ return -EEXIST;
+
+ return 0;
+ }
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ while (size) {
+ len = read(fd, digest_list_buf, sizeof(digest_list_buf));
+ if (len <= 0) {
+ ret = -errno;
+ goto out;
+ }
+
+ if (memcmp(digest_list_buf,
+ digest_list->buf + digest_list->size - size, len)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ size -= len;
+ }
+
+ close(fd);
+
+ path[path_len - 6] = '.';
+
+ fd = open(path, O_RDONLY);
+ if (fd < 0)
+ return -errno;
+
+ size = digest_list->size;
+ while (size) {
+ hdr = (struct compact_list_hdr *)(digest_list->buf +
+ digest_list->size - size);
+
+ /* From digest_list_show_common(). */
+ len = snprintf(digest_list_info, sizeof(digest_list_info),
+ "actions: %d, version: %d, algo: %s, type: %d, modifiers: %d, count: %d, datalen: %d\n",
+ digest_list->actions, hdr->version,
+ hash_algo_name[hdr->algo], hdr->type, hdr->modifiers,
+ hdr->count, hdr->datalen);
+
+ read_len = read(fd, digest_list_buf, len);
+
+ if (read_len != len ||
+ memcmp(digest_list_info, digest_list_buf, len)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ size -= sizeof(*hdr);
+
+ for (i = 0; i < hdr->count; i++) {
+ _bin2hex(digest_list_info,
+ digest_list->buf + digest_list->size - size,
+ hash_digest_size[hdr->algo]);
+
+ read_len = read(fd, digest_list_buf,
+ hash_digest_size[hdr->algo] * 2 + 1);
+
+ if (read_len != hash_digest_size[hdr->algo] * 2 + 1 ||
+ memcmp(digest_list_info, digest_list_buf,
+ read_len - 1) ||
+ digest_list_buf[read_len - 1] != '\n') {
+ ret = -EIO;
+ goto out;
+ }
+
+ size -= hash_digest_size[hdr->algo];
+ }
+ }
+out:
+ close(fd);
+ return ret;
+}
+
+static int digest_list_query(u8 *digest, enum hash_algo algo,
+ char **query_result)
+{
+ ssize_t len, to_write, written;
+ char query[256] = { 0 };
+ size_t query_result_len;
+ int ret = 0, fd;
+
+ len = snprintf(query, sizeof(query), "%s-", hash_algo_name[algo]);
+
+ _bin2hex(query + len, digest, hash_digest_size[algo]);
+ len += hash_digest_size[algo] * 2 + 1;
+
+ fd = open(DIGEST_QUERY_PATH, O_WRONLY);
+ if (fd < 0)
+ return -errno;
+
+ to_write = len;
+
+ while (to_write) {
+ written = write(fd, query + len - to_write, to_write);
+ if (written <= 0) {
+ ret = -errno;
+ break;
+ }
+
+ to_write -= written;
+ }
+
+ close(fd);
+ if (ret < 0)
+ return ret;
+
+ return read_buffer(DIGEST_QUERY_PATH, query_result, &query_result_len,
+ true, true);
+}
+
+static int *get_count_gen_lists(u8 *digest, enum hash_algo algo,
+ bool is_digest_list)
+{
+ struct compact_list_hdr *hdr;
+ u8 *buf_ptr;
+ unsigned long long size;
+ struct digest_list_item *digest_list;
+ u8 digest_list_digest[64];
+ int i, j, *count;
+
+ count = calloc(num_max_digest_lists, sizeof(*count));
+ if (!count)
+ return count;
+
+ for (i = 0; i < num_max_digest_lists; i++) {
+ if (!digest_lists[i])
+ continue;
+
+ digest_list = digest_lists[i];
+ size = digest_lists[i]->size;
+ buf_ptr = digest_lists[i]->buf;
+
+ if (is_digest_list) {
+ _hex2bin(digest_list_digest, digest_list->digest_str,
+ hash_digest_size[digest_list->algo]);
+ if (!memcmp(digest_list_digest, digest,
+ hash_digest_size[digest_list->algo]))
+ count[i]++;
+
+ continue;
+ }
+
+ while (size) {
+ hdr = (struct compact_list_hdr *)buf_ptr;
+ if (hdr->algo != algo) {
+ buf_ptr += sizeof(*hdr) + hdr->datalen;
+ size -= sizeof(*hdr) + hdr->datalen;
+ continue;
+ }
+
+ buf_ptr += sizeof(*hdr);
+ size -= sizeof(*hdr);
+
+ for (j = 0; j < hdr->count; j++) {
+ if (!memcmp(digest, buf_ptr,
+ hash_digest_size[algo]))
+ count[i]++;
+ buf_ptr += hash_digest_size[algo];
+ size -= hash_digest_size[algo];
+ }
+ }
+ }
+
+ return count;
+}
+
+static int *get_count_kernel_query(u8 *digest, enum hash_algo algo,
+ bool is_digest_list)
+{
+ char *query_result = NULL, *query_result_ptr, *line;
+ char digest_list_info[MAX_LINE_LENGTH];
+ char label[256];
+ struct compact_list_hdr *hdr;
+ struct digest_list_item *digest_list;
+ unsigned long long size, size_info;
+ int ret, i, *count = NULL;
+
+ count = calloc(num_max_digest_lists, sizeof(*count));
+ if (!count)
+ return count;
+
+ ret = digest_list_query(digest, algo, &query_result);
+ if (ret < 0)
+ goto out;
+
+ query_result_ptr = query_result;
+
+ while ((line = strsep(&query_result_ptr, "\n"))) {
+ if (!strlen(line))
+ continue;
+
+ for (i = 0; i < num_max_digest_lists; i++) {
+ if (!digest_lists[i])
+ continue;
+
+ digest_list = digest_lists[i];
+ size = digest_list->size;
+
+ if (is_digest_list) {
+ snprintf(label, sizeof(label),
+ "%s-%s-digest_list.%s",
+ hash_algo_name[digest_list->algo],
+ digest_list->digest_str,
+ digest_list->filename_suffix);
+
+ /* From digest_query_show(). */
+ size_info = snprintf(digest_list_info,
+ sizeof(digest_list_info),
+ "%s (actions: %d): type: %d, size: %lld\n",
+ label, digest_list->actions,
+ COMPACT_DIGEST_LIST, size);
+
+ /* strsep() replaced '\n' with '\0' in line. */
+ digest_list_info[size_info - 1] = '\0';
+
+ if (!strcmp(digest_list_info, line))
+ count[i]++;
+
+ continue;
+ }
+
+ while (size) {
+ hdr =
+ (struct compact_list_hdr *)(digest_list->buf +
+ digest_list->size - size);
+ size -= sizeof(*hdr) + hdr->datalen;
+
+ snprintf(label, sizeof(label),
+ "%s-%s-digest_list.%s",
+ hash_algo_name[digest_list->algo],
+ digest_list->digest_str,
+ digest_list->filename_suffix);
+
+ /* From digest_query_show(). */
+ size_info = snprintf(digest_list_info,
+ sizeof(digest_list_info),
+ "%s (actions: %d): version: %d, algo: %s, type: %d, modifiers: %d, count: %d, datalen: %d\n",
+ label, digest_list->actions,
+ hdr->version,
+ hash_algo_name[hdr->algo], hdr->type,
+ hdr->modifiers, hdr->count,
+ hdr->datalen);
+
+ /* strsep() replaced '\n' with '\0' in line. */
+ digest_list_info[size_info - 1] = '\0';
+
+ if (!strcmp(digest_list_info, line)) {
+ count[i]++;
+ break;
+ }
+ }
+ }
+ }
+out:
+ free(query_result);
+ if (ret < 0)
+ free(count);
+
+ return (!ret) ? count : NULL;
+}
+
+static int compare_count(u8 *digest, enum hash_algo algo,
+ bool is_digest_list, struct __test_metadata *_metadata)
+{
+ int *count_gen_list_array, *count_kernel_query_array;
+ int count_gen_list = 0, count_kernel_query = 0;
+ char digest_str[64 * 2 + 1] = { 0 };
+ int i;
+
+ count_gen_list_array = get_count_gen_lists(digest, algo,
+ is_digest_list);
+ if (!count_gen_list_array)
+ return -EINVAL;
+
+ count_kernel_query_array = get_count_kernel_query(digest, algo,
+ is_digest_list);
+ if (!count_kernel_query_array) {
+ free(count_gen_list_array);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < num_max_digest_lists; i++) {
+ count_gen_list += count_gen_list_array[i];
+ count_kernel_query += count_kernel_query_array[i];
+ }
+
+ _bin2hex(digest_str, digest, hash_digest_size[algo]);
+
+ TH_LOG("digest: %s, algo: %s, gen list digests: %d, kernel digests: %d",
+ digest_str, hash_algo_name[algo], count_gen_list,
+ count_kernel_query);
+ free(count_gen_list_array);
+ free(count_kernel_query_array);
+ return (count_gen_list == count_kernel_query) ? 0 : -EINVAL;
+}
+
+static void digest_list_delete_all(struct __test_metadata *_metadata,
+ enum upload_types upload_type)
+{
+ int ret, i;
+
+ for (i = 0; i < MAX_DIGEST_LISTS; i++) {
+ if (!digest_lists[i])
+ continue;
+
+ ret = digest_list_upload(digest_lists[i], DIGEST_LIST_DEL,
+ upload_type, -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed\n");
+ }
+
+ free(digest_lists[i]->buf);
+ free(digest_lists[i]);
+ digest_lists[i] = NULL;
+ }
+}
+
+FIXTURE(test)
+{
+ enum upload_types upload_type;
+};
+
+FIXTURE_SETUP(test)
+{
+}
+
+FIXTURE_TEARDOWN(test)
+{
+ digest_list_delete_all(_metadata, self->upload_type);
+}
+
+static int enable_fault_injection(void)
+{
+ int ret;
+
+ ret = write_buffer(DIGEST_LIST_DEBUGFS_TASK_FILTER, "Y", 1, -1);
+ if (ret < 0)
+ return ret;
+
+ ret = write_buffer(DIGEST_LIST_DEBUGFS_PROBABILITY, "1", 1, -1);
+ if (ret < 0)
+ return ret;
+
+ ret = write_buffer(DIGEST_LIST_DEBUGFS_TIMES, "10000", 5, -1);
+ if (ret < 0)
+ return ret;
+
+ ret = write_buffer(DIGEST_LIST_DEBUGFS_VERBOSE, "1", 1, -1);
+ if (ret < 0)
+ return ret;
+
+ ret = write_buffer(PROCFS_SELF_FAULT, "1", 1, -1);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static void digest_list_add_del_test(struct __test_metadata *_metadata,
+ int fault_injection,
+ enum upload_types upload_type)
+{
+ u32 value;
+ enum ops op;
+ enum hash_algo algo;
+ u8 digest[64];
+ int ret, i, cur_queries = 1;
+
+ while (cur_queries <= NUM_QUERIES) {
+ ret = getrandom(&op, 1, 0);
+ ASSERT_EQ(1, ret) {
+ TH_LOG("getrandom() failed\n");
+ }
+
+ op = op % 2;
+
+ switch (op) {
+ case DIGEST_LIST_ADD:
+ TH_LOG("add digest list...");
+ for (digest_lists_pos = 0;
+ digest_lists_pos < num_max_digest_lists;
+ digest_lists_pos++)
+ if (!digest_lists[digest_lists_pos])
+ break;
+
+ if (digest_lists_pos == num_max_digest_lists)
+ continue;
+
+ digest_lists[digest_lists_pos] = digest_list_generate();
+ ASSERT_NE(NULL, digest_lists[digest_lists_pos]) {
+ TH_LOG("digest_list_generate() failed");
+ }
+
+ ret = digest_list_upload(digest_lists[digest_lists_pos],
+ op, upload_type, -1);
+ /* Handle failures from fault injection. */
+ if (fault_injection && ret < 0) {
+ TH_LOG("handle failure...");
+ ret = digest_list_check(
+ digest_lists[digest_lists_pos],
+ DIGEST_LIST_DEL);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ free(digest_lists[digest_lists_pos]->buf);
+ free(digest_lists[digest_lists_pos]);
+ digest_lists[digest_lists_pos] = NULL;
+ break;
+ }
+
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[digest_lists_pos],
+ op);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ break;
+ case DIGEST_LIST_DEL:
+ TH_LOG("delete digest list...");
+ for (digest_lists_pos = 0;
+ digest_lists_pos < num_max_digest_lists;
+ digest_lists_pos++)
+ if (digest_lists[digest_lists_pos])
+ break;
+
+ if (digest_lists_pos == num_max_digest_lists)
+ continue;
+
+ for (i = 0; i < MAX_SEARCH_ATTEMPTS; i++) {
+ ret = getrandom(&digest_lists_pos,
+ sizeof(digest_lists_pos), 0);
+ ASSERT_EQ(sizeof(digest_lists_pos), ret) {
+ TH_LOG("getrandom() failed");
+ }
+
+ digest_lists_pos =
+ digest_lists_pos % num_max_digest_lists;
+
+ if (digest_lists[digest_lists_pos])
+ break;
+ }
+
+ if (i == MAX_SEARCH_ATTEMPTS) {
+ for (digest_lists_pos = 0;
+ digest_lists_pos < num_max_digest_lists;
+ digest_lists_pos++)
+ if (digest_lists[digest_lists_pos])
+ break;
+
+ if (digest_lists_pos == num_max_digest_lists)
+ continue;
+ }
+
+ ret = digest_list_upload(digest_lists[digest_lists_pos],
+ op, upload_type, -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[digest_lists_pos],
+ op);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ free(digest_lists[digest_lists_pos]->buf);
+ free(digest_lists[digest_lists_pos]);
+ digest_lists[digest_lists_pos] = NULL;
+ break;
+ default:
+ break;
+ }
+
+ ret = getrandom(&value, sizeof(value), 0);
+ ASSERT_EQ(sizeof(value), ret) {
+ TH_LOG("getrandom() failed");
+ }
+
+ value = value % 10;
+
+ if (value != 1)
+ continue;
+
+ ret = getrandom(&value, sizeof(value), 0);
+ ASSERT_EQ(sizeof(value), ret) {
+ TH_LOG("getrandom() failed");
+ }
+
+ value = value % MAX_DIGEST_VALUE;
+
+ ret = getrandom(&algo, sizeof(algo), 0);
+ ASSERT_EQ(sizeof(algo), ret) {
+ TH_LOG("getrandom() failed");
+ }
+
+ algo = algo % HASH_ALGO_RIPE_MD_128;
+
+ memset(digest, 0, sizeof(digest));
+ *(u32 *)digest = value;
+
+ ret = compare_count(digest, algo, false, _metadata);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("count mismatch");
+ }
+
+ ret = getrandom(&value, sizeof(value), 0);
+ ASSERT_EQ(sizeof(value), ret) {
+ TH_LOG("getrandom() failed");
+ }
+
+ value = value % MAX_DIGEST_LISTS;
+
+ if (digest_lists[value] != NULL) {
+ _hex2bin(digest, digest_lists[value]->digest_str,
+ hash_digest_size[digest_lists[value]->algo]);
+
+ ret = compare_count(digest, digest_lists[value]->algo,
+ true, _metadata);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("count mismatch");
+ }
+ }
+
+ TH_LOG("query digest lists (%d/%d)...", cur_queries,
+ NUM_QUERIES);
+
+ cur_queries++;
+ }
+}
+
+TEST_F_TIMEOUT(test, digest_list_add_del_test_file_upload, UINT_MAX)
+{
+ self->upload_type = UPLOAD_FILE;
+ digest_list_add_del_test(_metadata, 0, self->upload_type);
+}
+
+TEST_F_TIMEOUT(test, digest_list_add_del_test_file_upload_fault, UINT_MAX)
+{
+ int ret;
+
+ self->upload_type = UPLOAD_FILE;
+
+ ret = enable_fault_injection();
+ ASSERT_EQ(0, ret) {
+ TH_LOG("enable_fault_injection() failed");
+ }
+
+ digest_list_add_del_test(_metadata, 1, self->upload_type);
+}
+
+TEST_F_TIMEOUT(test, digest_list_add_del_test_buffer_upload, UINT_MAX)
+{
+ self->upload_type = UPLOAD_BUFFER;
+ digest_list_add_del_test(_metadata, 0, self->upload_type);
+}
+
+TEST_F_TIMEOUT(test, digest_list_add_del_test_buffer_upload_fault, UINT_MAX)
+{
+ int ret;
+
+ self->upload_type = UPLOAD_BUFFER;
+
+ ret = enable_fault_injection();
+ ASSERT_EQ(0, ret) {
+ TH_LOG("enable_fault_injection() failed");
+ }
+
+ digest_list_add_del_test(_metadata, 1, self->upload_type);
+}
+
+FIXTURE(test_fuzzing)
+{
+};
+
+FIXTURE_SETUP(test_fuzzing)
+{
+}
+
+FIXTURE_TEARDOWN(test_fuzzing)
+{
+}
+
+TEST_F_TIMEOUT(test_fuzzing, digest_list_fuzzing_test, UINT_MAX)
+{
+ char digests_count_before[256] = { 0 };
+ char *digests_count_before_ptr = digests_count_before;
+ char digests_count_after[256] = { 0 };
+ char *digests_count_after_ptr = digests_count_after;
+ size_t len = sizeof(digests_count_before) - 1;
+ int ret, i;
+
+ ret = read_buffer(DIGESTS_COUNT, &digests_count_before_ptr, &len,
+ false, true);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("read_buffer() failed");
+ }
+
+ for (i = 1; i <= NUM_ITERATIONS; i++) {
+ TH_LOG("add digest list (%d/%d)...", i, NUM_ITERATIONS);
+
+ digest_lists[0] = digest_list_generate_random();
+ ASSERT_NE(NULL, digest_lists[0]) {
+ TH_LOG("digest_list_generate() failed");
+ }
+
+ ret = digest_list_upload(digest_lists[0], DIGEST_LIST_ADD,
+ UPLOAD_FILE, -1);
+ if (!ret) {
+ ret = digest_list_check(digest_lists[0],
+ DIGEST_LIST_ADD);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ ret = digest_list_upload(digest_lists[0],
+ DIGEST_LIST_DEL, UPLOAD_FILE,
+ -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[0],
+ DIGEST_LIST_DEL);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+ }
+
+ free(digest_lists[0]->buf);
+ free(digest_lists[0]);
+ digest_lists[0] = NULL;
+ }
+
+ ret = read_buffer(DIGESTS_COUNT, &digests_count_after_ptr, &len, false,
+ true);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("read_buffer() failed");
+ }
+
+ ASSERT_STREQ(digests_count_before, digests_count_after);
+}
+
+#define IMA_MEASURE_RULES "dont_measure func=CRITICAL_DATA label=diglim euid=1000 \nmeasure func=CRITICAL_DATA label=diglim \n"
+
+/* This must be the last group of tests, otherwise an OOM will likely occur. */
+FIXTURE(test_measure)
+{
+};
+
+FIXTURE_SETUP(test_measure)
+{
+ char *cur_ima_policy = NULL;
+ size_t cur_ima_policy_len = 0;
+ bool rule_found = false;
+ int ret;
+
+ ret = read_buffer(IMA_POLICY_PATH, &cur_ima_policy, &cur_ima_policy_len,
+ true, true);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("read_buffer() failed");
+ }
+
+ rule_found = (strstr(cur_ima_policy, IMA_MEASURE_RULES) != NULL);
+ free(cur_ima_policy);
+
+ if (!rule_found) {
+ ret = write_buffer(IMA_POLICY_PATH, IMA_MEASURE_RULES,
+ sizeof(IMA_MEASURE_RULES), -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("write_buffer() failed");
+ }
+ }
+}
+
+FIXTURE_TEARDOWN(test_measure)
+{
+}
+
+TEST_F_TIMEOUT(test_measure, digest_list_add_del_test_file_upload_measured,
+ UINT_MAX)
+{
+ int ret;
+
+ digest_lists[0] = digest_list_generate();
+ ASSERT_NE(NULL, digest_lists[0]) {
+ TH_LOG("digest_list_generate() failed");
+ }
+
+ digest_lists[0]->actions |= (1 << COMPACT_ACTION_IMA_MEASURED);
+
+ ret = digest_list_upload(digest_lists[0], DIGEST_LIST_ADD, UPLOAD_FILE,
+ -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[0], DIGEST_LIST_ADD);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ ret = digest_list_upload(digest_lists[0], DIGEST_LIST_DEL, UPLOAD_FILE,
+ -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[0], DIGEST_LIST_DEL);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ free(digest_lists[0]->buf);
+ free(digest_lists[0]);
+ digest_lists[0] = NULL;
+}
+
+void digest_list_check_measurement_list_test_common(
+ struct __test_metadata *_metadata,
+ enum upload_types upload_type)
+{
+ char *measurement_list = NULL;
+ size_t measurement_list_len;
+ char event_digest_name[512];
+ bool entry_found;
+ int ret;
+
+ digest_lists[0] = digest_list_generate();
+ ASSERT_NE(NULL, digest_lists[0]) {
+ TH_LOG("digest_list_generate() failed");
+ }
+
+ digest_lists[0]->actions |= (1 << COMPACT_ACTION_IMA_MEASURED);
+
+ ret = digest_list_upload(digest_lists[0], DIGEST_LIST_ADD, upload_type,
+ -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[0], DIGEST_LIST_ADD);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ ret = read_buffer(IMA_MEASUREMENTS_PATH, &measurement_list,
+ &measurement_list_len, true, true);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("read_buffer() failed");
+ }
+
+ snprintf(event_digest_name, sizeof(event_digest_name),
+ "%s:%s add_%s_digest_list.%s",
+ hash_algo_name[digest_lists[0]->algo],
+ digest_lists[0]->digest_str,
+ upload_type == UPLOAD_FILE ? "file" : "buffer",
+ digest_lists[0]->filename_suffix);
+
+ entry_found = (strstr(measurement_list, event_digest_name) != NULL);
+ free(measurement_list);
+
+ ASSERT_EQ(true, entry_found) {
+ TH_LOG("digest list not found in measurement list");
+ }
+
+ ret = digest_list_upload(digest_lists[0], DIGEST_LIST_DEL, upload_type,
+ 1000);
+ ASSERT_NE(0, ret) {
+ TH_LOG("digest_list_upload() success unexpected");
+ }
+
+ ret = digest_list_upload(digest_lists[0], DIGEST_LIST_DEL, upload_type,
+ -1);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_upload() failed");
+ }
+
+ ret = digest_list_check(digest_lists[0], DIGEST_LIST_DEL);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("digest_list_check() failed");
+ }
+
+ measurement_list = NULL;
+
+ ret = read_buffer(IMA_MEASUREMENTS_PATH, &measurement_list,
+ &measurement_list_len, true, true);
+ ASSERT_EQ(0, ret) {
+ TH_LOG("read_buffer() failed");
+ }
+
+ snprintf(event_digest_name, sizeof(event_digest_name),
+ "%s:%s del_%s_digest_list.%s",
+ hash_algo_name[digest_lists[0]->algo],
+ digest_lists[0]->digest_str,
+ upload_type == UPLOAD_FILE ? "file" : "buffer",
+ digest_lists[0]->filename_suffix);
+
+ entry_found = (strstr(measurement_list, event_digest_name) != NULL);
+ free(measurement_list);
+
+ ASSERT_EQ(true, entry_found) {
+ TH_LOG("digest list not found in measurement list");
+ }
+
+ free(digest_lists[0]->buf);
+ free(digest_lists[0]);
+ digest_lists[0] = NULL;
+}
+
+TEST_F_TIMEOUT(test_measure,
+ digest_list_check_measurement_list_test_file_upload, UINT_MAX)
+{
+ digest_list_check_measurement_list_test_common(_metadata, UPLOAD_FILE);
+}
+
+TEST_F_TIMEOUT(test_measure,
+ digest_list_check_measurement_list_test_buffer_upload, UINT_MAX)
+{
+ digest_list_check_measurement_list_test_common(_metadata,
+ UPLOAD_BUFFER);
+}
+
+TEST_HARNESS_MAIN
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 11/12] diglim: Remote Attestation
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Add more information about remote attestation with IMA and DIGLIM in
Documentation/security/diglim/remote_attestation.rst.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
Documentation/security/diglim/index.rst | 1 +
.../security/diglim/remote_attestation.rst | 87 +++++++++++++++++++
MAINTAINERS | 1 +
3 files changed, 89 insertions(+)
create mode 100644 Documentation/security/diglim/remote_attestation.rst
diff --git a/Documentation/security/diglim/index.rst b/Documentation/security/diglim/index.rst
index 4771134c2f0d..0f28c5ad71c0 100644
--- a/Documentation/security/diglim/index.rst
+++ b/Documentation/security/diglim/index.rst
@@ -10,3 +10,4 @@ Digest Lists Integrity Module (DIGLIM)
introduction
architecture
implementation
+ remote_attestation
diff --git a/Documentation/security/diglim/remote_attestation.rst b/Documentation/security/diglim/remote_attestation.rst
new file mode 100644
index 000000000000..83fd7581c460
--- /dev/null
+++ b/Documentation/security/diglim/remote_attestation.rst
@@ -0,0 +1,87 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Remote Attestation
+==================
+
+When a digest list is added or deleted through the ``digest_list_add`` or
+``digest_list_del`` interfaces, its buffer is sent to the IMA function
+``ima_measure_critical_data()``. The primary reason for it is to calculate
+the buffer digest, so that the digest list itself is searchable in the hash
+table.
+
+``ima_measure_critical_data()`` can be also used to create a new
+measurement entry each time this function is called, if there is an
+appropriate rule in the IMA policy. Given that this function is called
+during an addition or deletion of a digest list, a remote verifier can
+infer from the measurement list precise information about what has been
+uploaded to the kernel.
+
+To enable this functionality, the following rule must be added to the IMA
+policy:
+
+::
+
+ measure func=CRITICAL_DATA label=diglim
+
+
+When a file is uploaded, the workflow and the resulting IMA measurement
+list are:
+
+.. code-block:: bash
+
+ # echo $PWD/0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_list_add
+ # echo $PWD/0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_list_del
+ # cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements
+ ...
+ 10 <template digest> ima-buf sha256:<buffer digest> add_file_0-file_list-compact-cat <buffer>
+ 10 <template digest> ima-buf sha256:<buffer digest> del_file_0-file_list-compact-cat <buffer>
+
+When a buffer is uploaded, the workflow and the resulting IMA measurement
+list are:
+
+.. code-block:: bash
+
+ # echo 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_label
+ # cat 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_list_add
+ # echo 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_label
+ # cat 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_list_del
+ # cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements
+ ...
+ 10 <template digest> ima-buf sha256:<buffer digest> add_buffer_0-file_list-compact-cat <buffer>
+ 10 <template digest> ima-buf sha256:<buffer digest> del_buffer_0-file_list-compact-cat <buffer>
+
+In the second case, the digest list label must be set explicitly, as the
+kernel cannot determine it by itself (in the first case it is derived from
+the name of the file uploaded).
+
+The confirmation that the digest list has been processed by IMA can be
+obtained by reading the ASCII representation of the digest list:
+
+.. code-block:: bash
+
+ # cat /sys/kernel/security/integrity/diglim/digest_lists_loaded/sha256-<digest list digest>-0-file_list-compact-cat.ascii
+ actions: 1, version: 1, algo: sha256, type: 2, modifiers: 1, count: 1, datalen: 32
+ 87e5bd81850e11eeec2d3bb696b626b2a7f45673241cbbd64769c83580432869
+
+In this output, ``actions`` is set to 1 (``COMPACT_ACTION_IMA_MEASURED``
+bit set).
+
+
+DIGLIM guarantees that the information reported in the IMA measurement list
+is complete. If digest list loading is not recorded, digest query results
+are ignored by IMA. If the addition was recorded, deletion can be performed
+only if also the deletion is recorded. This can be seen in the following
+sequence of commands:
+
+.. code-block:: bash
+
+ # echo 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_label
+ # cat 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_list_add
+ # echo 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_label
+ # /tmp/cat 0-file_list-compact-cat > /sys/kernel/security/integrity/diglim/digest_list_del
+ diglim: actions mismatch, add: 1, del: 0
+ diglim: unable to upload generated digest list
+ /tmp/cat: write error: Invalid argument
+
+Digest list measurement is avoided with the execution of ``/tmp/cat``, for
+which a dont_measure rule was previously added in the IMA policy.
diff --git a/MAINTAINERS b/MAINTAINERS
index 0672128fae7f..a7c502685109 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5461,6 +5461,7 @@ F: Documentation/security/diglim/architecture.rst
F: Documentation/security/diglim/implementation.rst
F: Documentation/security/diglim/index.rst
F: Documentation/security/diglim/introduction.rst
+F: Documentation/security/diglim/remote_attestation.rst
F: include/linux/diglim.h
F: include/uapi/linux/diglim.h
F: security/integrity/diglim/diglim.h
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 10/12] diglim: Interfaces - digests_count
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu, kernel test robot
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the digests_count interface, which shows the current number of
digests stored in the hash table by type.
Reported-by: kernel test robot <lkp@intel.com> (frame size warning)
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
security/integrity/diglim/fs.c | 48 ++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c
index f1c1fc56448a..3b1d9616cb62 100644
--- a/security/integrity/diglim/fs.c
+++ b/security/integrity/diglim/fs.c
@@ -23,6 +23,7 @@
#include "diglim.h"
#define MAX_DIGEST_LIST_SIZE (64 * 1024 * 1024 - 1)
+#define TMPBUF_SIZE 512
static struct dentry *diglim_dir;
/**
@@ -36,6 +37,13 @@ static struct dentry *diglim_dir;
* removed.
*/
static struct dentry *digest_lists_loaded_dir;
+/**
+ * DOC: digests_count
+ *
+ * digests_count shows the current number of digests stored in the hash
+ * table by type.
+ */
+static struct dentry *digests_count;
/**
* DOC: digest_label
*
@@ -73,6 +81,39 @@ static struct dentry *digest_list_del_dentry;
char digest_query[CRYPTO_MAX_ALG_NAME + 1 + IMA_MAX_DIGEST_SIZE * 2 + 1];
char digest_label[NAME_MAX + 1];
+static char *types_str[COMPACT__LAST] = {
+ [COMPACT_PARSER] = "Parser",
+ [COMPACT_FILE] = "File",
+ [COMPACT_METADATA] = "Metadata",
+ [COMPACT_DIGEST_LIST] = "Digest list",
+};
+
+static ssize_t diglim_show_htable_len(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ char *tmpbuf;
+ ssize_t ret, len = 0;
+ int i;
+
+ tmpbuf = kmalloc(TMPBUF_SIZE, GFP_KERNEL);
+ if (!tmpbuf)
+ return -ENOMEM;
+
+ for (i = COMPACT_PARSER; i < COMPACT__LAST; i++)
+ len += scnprintf(tmpbuf + len, TMPBUF_SIZE - len,
+ "%s digests: %lu\n", types_str[i],
+ htable[i].len);
+
+ ret = simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
+ kfree(tmpbuf);
+ return ret;
+}
+
+static const struct file_operations htable_len_ops = {
+ .read = diglim_show_htable_len,
+ .llseek = generic_file_llseek,
+};
+
static int parse_digest_list_filename(const char *digest_list_filename,
u8 *digest, enum hash_algo *algo)
{
@@ -696,6 +737,12 @@ static int __init diglim_fs_init(void)
if (IS_ERR(digest_lists_loaded_dir))
goto out;
+ digests_count = securityfs_create_file("digests_count", 0440,
+ diglim_dir, NULL,
+ &htable_len_ops);
+ if (IS_ERR(digests_count))
+ goto out;
+
digest_list_add_dentry = securityfs_create_file("digest_list_add", 0200,
diglim_dir, NULL,
&digest_list_upload_ops);
@@ -726,6 +773,7 @@ static int __init diglim_fs_init(void)
securityfs_remove(digest_label_dentry);
securityfs_remove(digest_list_del_dentry);
securityfs_remove(digest_list_add_dentry);
+ securityfs_remove(digests_count);
securityfs_remove(digest_lists_loaded_dir);
securityfs_remove(diglim_dir);
return -1;
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 07/12] diglim: Interfaces - digest_lists_loaded
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the digest_lists_loaded directory in
<securityfs>/integrity/diglim.
It contains two files for each loaded digest list: one shows the digest
list in binary format, and the other (with .ascii prefix) shows the digest
list in ASCII format.
Files are added and removed at the same time digest lists are added and
removed.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
security/integrity/diglim/fs.c | 307 ++++++++++++++++++++++++++++++++-
1 file changed, 304 insertions(+), 3 deletions(-)
diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c
index 07a0d75a0e33..caf2923c9146 100644
--- a/security/integrity/diglim/fs.c
+++ b/security/integrity/diglim/fs.c
@@ -25,6 +25,17 @@
#define MAX_DIGEST_LIST_SIZE (64 * 1024 * 1024 - 1)
static struct dentry *diglim_dir;
+/**
+ * DOC: digest_lists_loaded
+ *
+ * digest_lists_loaded is a directory containing two files for each
+ * loaded digest list: one shows the digest list in binary format, and the
+ * other (with .ascii prefix) shows the digest list in ASCII format.
+ *
+ * Files are added and removed at the same time digest lists are added and
+ * removed.
+ */
+static struct dentry *digest_lists_loaded_dir;
/**
* DOC: digest_list_add
*
@@ -47,6 +58,245 @@ static struct dentry *digest_list_add_dentry;
static struct dentry *digest_list_del_dentry;
char digest_label[NAME_MAX + 1];
+static int parse_digest_list_filename(const char *digest_list_filename,
+ u8 *digest, enum hash_algo *algo)
+{
+ int i;
+
+ for (i = 0; i < HASH_ALGO__LAST; i++)
+ if (!strncmp(digest_list_filename, hash_algo_name[i],
+ strlen(hash_algo_name[i])))
+ break;
+
+ if (i == HASH_ALGO__LAST)
+ return -ENOENT;
+
+ *algo = i;
+ return hex2bin(digest, strchr(digest_list_filename, '-') + 1,
+ hash_digest_size[*algo]);
+}
+
+/* *pos is the offset of the digest list data to show. */
+static void *digest_list_start(struct seq_file *m, loff_t *pos)
+{
+ struct digest_item *d;
+ u8 digest[IMA_MAX_DIGEST_SIZE];
+ enum hash_algo algo;
+ struct digest_list_item *digest_list;
+ int ret;
+
+ if (m->private) {
+ digest_list = (struct digest_list_item *)m->private;
+
+ if (*pos == digest_list->size)
+ return NULL;
+
+ return digest_list->buf + *pos;
+ }
+
+ ret = parse_digest_list_filename(file_dentry(m->file)->d_name.name,
+ digest, &algo);
+ if (ret < 0)
+ return NULL;
+
+ d = __digest_lookup(digest, algo, COMPACT_DIGEST_LIST, NULL, NULL);
+ if (!d)
+ return NULL;
+
+ digest_list = list_first_entry(&d->refs,
+ struct digest_list_item_ref, list)->digest_list;
+ m->private = digest_list;
+ return digest_list->buf;
+}
+
+static void *digest_list_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct compact_list_hdr *hdr;
+ struct digest_list_item *digest_list =
+ (struct digest_list_item *)m->private;
+ void *bufp = digest_list->buf;
+ bool is_header = false;
+
+ /* Determine if v points to a header or a digest. */
+ while (bufp <= v) {
+ hdr = (struct compact_list_hdr *)bufp;
+ if (bufp == v) {
+ is_header = true;
+ break;
+ }
+
+ bufp += sizeof(*hdr) + hdr->datalen;
+ }
+
+ if (is_header)
+ *pos += sizeof(*hdr);
+ else
+ *pos += hash_digest_size[hdr->algo];
+
+ if (*pos == digest_list->size)
+ return NULL;
+
+ return digest_list->buf + *pos;
+}
+
+static void digest_list_stop(struct seq_file *m, void *v)
+{
+}
+
+static void print_digest(struct seq_file *m, u8 *digest, u32 size)
+{
+ u32 i;
+
+ for (i = 0; i < size; i++)
+ seq_printf(m, "%02x", *(digest + i));
+}
+
+static void digest_list_putc(struct seq_file *m, void *data, int datalen)
+{
+ while (datalen--)
+ seq_putc(m, *(char *)data++);
+}
+
+static int digest_list_show_common(struct seq_file *m, void *v, bool binary)
+{
+ struct compact_list_hdr *hdr;
+ struct digest_list_item *digest_list =
+ (struct digest_list_item *)m->private;
+ void *bufp = digest_list->buf;
+ bool is_header = false;
+
+ /* Determine if v points to a header or a digest. */
+ while (bufp <= v) {
+ hdr = (struct compact_list_hdr *)bufp;
+ if (bufp == v) {
+ is_header = true;
+ break;
+ }
+
+ bufp += sizeof(*hdr) + hdr->datalen;
+ }
+
+ if (is_header) {
+ if (binary)
+ digest_list_putc(m, v, sizeof(*hdr));
+ else
+ seq_printf(m,
+ "actions: %d, version: %d, algo: %s, type: %d, modifiers: %d, count: %d, datalen: %d\n",
+ digest_list->actions, hdr->version,
+ hash_algo_name[hdr->algo], hdr->type,
+ hdr->modifiers, hdr->count, hdr->datalen);
+ return 0;
+ }
+
+ if (binary) {
+ digest_list_putc(m, v, hash_digest_size[hdr->algo]);
+ } else {
+ print_digest(m, v, hash_digest_size[hdr->algo]);
+ seq_puts(m, "\n");
+ }
+
+ return 0;
+}
+
+static int digest_list_show(struct seq_file *m, void *v)
+{
+ return digest_list_show_common(m, v, true);
+}
+
+static int digest_list_ascii_show(struct seq_file *m, void *v)
+{
+ return digest_list_show_common(m, v, false);
+}
+
+static const struct seq_operations digest_list_seqops = {
+ .start = digest_list_start,
+ .next = digest_list_next,
+ .stop = digest_list_stop,
+ .show = digest_list_show
+};
+
+static int digest_list_seq_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &digest_list_seqops);
+}
+
+static const struct file_operations digest_list_ops = {
+ .open = digest_list_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static const struct seq_operations digest_list_ascii_seqops = {
+ .start = digest_list_start,
+ .next = digest_list_next,
+ .stop = digest_list_stop,
+ .show = digest_list_ascii_show
+};
+
+static int digest_list_ascii_seq_open(struct inode *inode, struct file *file)
+{
+ return seq_open(file, &digest_list_ascii_seqops);
+}
+
+static const struct file_operations digest_list_ascii_ops = {
+ .open = digest_list_ascii_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = seq_release,
+};
+
+static int digest_list_get_secfs_files(char *label, u8 *digest,
+ enum hash_algo algo, enum ops op,
+ struct dentry **dentry,
+ struct dentry **dentry_ascii)
+{
+ char digest_list_filename[NAME_MAX + 1] = { 0 };
+ u8 digest_str[IMA_MAX_DIGEST_SIZE * 2 + 1] = { 0 };
+ char *dot, *label_ptr;
+
+ label_ptr = strrchr(label, '/');
+ if (label_ptr)
+ label = label_ptr + 1;
+
+ bin2hex(digest_str, digest, hash_digest_size[algo]);
+
+ snprintf(digest_list_filename, sizeof(digest_list_filename),
+ "%s-%s-%s.ascii", hash_algo_name[algo], digest_str, label);
+
+ dot = strrchr(digest_list_filename, '.');
+
+ *dot = '\0';
+ if (op == DIGEST_LIST_ADD)
+ *dentry = securityfs_create_file(digest_list_filename, 0440,
+ digest_lists_loaded_dir, NULL,
+ &digest_list_ops);
+ else
+ *dentry = lookup_positive_unlocked(digest_list_filename,
+ digest_lists_loaded_dir,
+ strlen(digest_list_filename));
+ *dot = '.';
+ if (IS_ERR(*dentry))
+ return PTR_ERR(*dentry);
+
+ if (op == DIGEST_LIST_ADD)
+ *dentry_ascii = securityfs_create_file(digest_list_filename,
+ 0440, digest_lists_loaded_dir,
+ NULL, &digest_list_ascii_ops);
+ else
+ *dentry_ascii = lookup_positive_unlocked(digest_list_filename,
+ digest_lists_loaded_dir,
+ strlen(digest_list_filename));
+ if (IS_ERR(*dentry_ascii)) {
+ if (op == DIGEST_LIST_ADD)
+ securityfs_remove(*dentry);
+
+ return PTR_ERR(*dentry_ascii);
+ }
+
+ return 0;
+}
+
/*
* digest_list_read: read and parse the digest list from the path
*/
@@ -60,6 +310,7 @@ static ssize_t digest_list_read(char *path, enum ops op)
char event_name[NAME_MAX + 9 + 1];
u8 digest[IMA_MAX_DIGEST_SIZE] = { 0 };
enum hash_algo algo;
+ struct dentry *dentry, *dentry_ascii;
int rc, pathlen = strlen(path);
/* Remove \n. */
@@ -95,9 +346,27 @@ static ssize_t digest_list_read(char *path, enum ops op)
if (!rc || rc == -EEXIST)
actions |= (1 << COMPACT_ACTION_IMA_MEASURED);
- rc = digest_list_parse(size, data, op, actions, digest, algo, "");
+ rc = digest_list_get_secfs_files(path, digest, algo, op, &dentry,
+ &dentry_ascii);
+ if (rc < 0)
+ goto out_vfree;
+
+ rc = digest_list_parse(size, data, op, actions, digest, algo,
+ dentry->d_name.name);
if (rc < 0)
pr_err("unable to upload digest list %s (%d)\n", path, rc);
+
+ /* Release reference taken in digest_list_get_secfs_files(). */
+ if (op == DIGEST_LIST_DEL) {
+ dput(dentry);
+ dput(dentry_ascii);
+ }
+
+ if ((rc < 0 && op == DIGEST_LIST_ADD) ||
+ (rc == size && op == DIGEST_LIST_DEL)) {
+ securityfs_remove(dentry);
+ securityfs_remove(dentry_ascii);
+ }
out_vfree:
vfree(data);
out:
@@ -116,9 +385,10 @@ static ssize_t digest_list_write(struct file *file, const char __user *buf,
size_t datalen, loff_t *ppos)
{
char *data;
+ char *digest_label_ptr;
ssize_t result;
enum ops op = DIGEST_LIST_ADD;
- struct dentry *dentry = file_dentry(file);
+ struct dentry *dentry = file_dentry(file), *dentry_ascii;
u8 digest[IMA_MAX_DIGEST_SIZE];
char event_name[NAME_MAX + 11 + 1];
enum hash_algo algo;
@@ -147,6 +417,10 @@ static ssize_t digest_list_write(struct file *file, const char __user *buf,
if (data[0] == '/') {
result = digest_list_read(data, op);
} else {
+ /* Remove \n. */
+ digest_label_ptr = digest_label;
+ strsep(&digest_label_ptr, "\n");
+
snprintf(event_name, sizeof(event_name), "%s_buffer_%s",
op == DIGEST_LIST_ADD ? "add" : "del", digest_label);
@@ -164,12 +438,33 @@ static ssize_t digest_list_write(struct file *file, const char __user *buf,
if (!result || result == -EEXIST)
actions |= (1 << COMPACT_ACTION_IMA_MEASURED);
+ result = digest_list_get_secfs_files(digest_label[0] != '\0' ?
+ digest_label : "parser",
+ digest, algo, op,
+ &dentry, &dentry_ascii);
+ if (result < 0)
+ goto out_kfree;
+
+ memset(digest_label, 0, sizeof(digest_label));
+
result = digest_list_parse(datalen, data, op, actions, digest,
- algo, "");
+ algo, dentry->d_name.name);
if (result != datalen) {
pr_err("unable to upload generated digest list\n");
result = -EINVAL;
}
+
+ /* Release reference taken in digest_list_get_secfs_files(). */
+ if (op == DIGEST_LIST_DEL) {
+ dput(dentry);
+ dput(dentry_ascii);
+ }
+
+ if ((result < 0 && op == DIGEST_LIST_ADD) ||
+ (result == datalen && op == DIGEST_LIST_DEL)) {
+ securityfs_remove(dentry);
+ securityfs_remove(dentry_ascii);
+ }
}
out_kfree:
kfree(data);
@@ -216,6 +511,11 @@ static int __init diglim_fs_init(void)
if (IS_ERR(diglim_dir))
return -1;
+ digest_lists_loaded_dir = securityfs_create_dir("digest_lists_loaded",
+ diglim_dir);
+ if (IS_ERR(digest_lists_loaded_dir))
+ goto out;
+
digest_list_add_dentry = securityfs_create_file("digest_list_add", 0200,
diglim_dir, NULL,
&digest_list_upload_ops);
@@ -232,6 +532,7 @@ static int __init diglim_fs_init(void)
out:
securityfs_remove(digest_list_del_dentry);
securityfs_remove(digest_list_add_dentry);
+ securityfs_remove(digest_lists_loaded_dir);
securityfs_remove(diglim_dir);
return -1;
}
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 09/12] diglim: Interfaces - digest_query
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the digest_query interface, which allows to write a query in the
format <algo>-<digest> and to obtain all digest lists that include that
digest.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
security/integrity/diglim/fs.c | 154 +++++++++++++++++++++++++++++++++
1 file changed, 154 insertions(+)
diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c
index 8958e987f708..f1c1fc56448a 100644
--- a/security/integrity/diglim/fs.c
+++ b/security/integrity/diglim/fs.c
@@ -43,6 +43,13 @@ static struct dentry *digest_lists_loaded_dir;
* list (buffer) loaded through digest_list_add.
*/
static struct dentry *digest_label_dentry;
+/**
+ * DOC: digest_query
+ *
+ * digest_query allows to write a query in the format <algo>-<digest> and
+ * to obtain all digest lists that include that digest.
+ */
+static struct dentry *digest_query_dentry;
/**
* DOC: digest_list_add
*
@@ -63,6 +70,7 @@ static struct dentry *digest_list_add_dentry;
* described for digest_list_add.
*/
static struct dentry *digest_list_del_dentry;
+char digest_query[CRYPTO_MAX_ALG_NAME + 1 + IMA_MAX_DIGEST_SIZE * 2 + 1];
char digest_label[NAME_MAX + 1];
static int parse_digest_list_filename(const char *digest_list_filename,
@@ -253,6 +261,84 @@ static const struct file_operations digest_list_ascii_ops = {
.release = seq_release,
};
+/*
+ * *pos is the n-th reference to show among all the references in all digest
+ * items found with the query.
+ */
+static void *digest_query_start(struct seq_file *m, loff_t *pos)
+{
+ struct digest_item *d;
+ u8 digest[IMA_MAX_DIGEST_SIZE];
+ enum hash_algo algo;
+ loff_t count = 0;
+ enum compact_types type = 0;
+ struct digest_list_item_ref *ref;
+ int ret;
+
+ ret = parse_digest_list_filename(digest_query, digest, &algo);
+ if (ret < 0)
+ return NULL;
+
+ for (type = 0; type < COMPACT__LAST; type++) {
+ d = __digest_lookup(digest, algo, type, NULL, NULL);
+ if (!d)
+ continue;
+
+ list_for_each_entry(ref, &d->refs, list) {
+ if (count++ == *pos) {
+ m->private = d;
+ return ref;
+ }
+ }
+ }
+
+ return NULL;
+}
+
+static void *digest_query_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct digest_item *d = (struct digest_item *)m->private;
+ struct digest_list_item_ref *cur_ref = (struct digest_list_item_ref *)v;
+ struct digest_list_item_ref *ref;
+
+ (*pos)++;
+
+ list_for_each_entry(ref, &d->refs, list) {
+ if (ref != cur_ref)
+ continue;
+
+ if (!list_is_last(&cur_ref->list, &d->refs))
+ return list_next_entry(cur_ref, list);
+ }
+
+ return NULL;
+}
+
+static void digest_query_stop(struct seq_file *m, void *v)
+{
+}
+
+static int digest_query_show(struct seq_file *m, void *v)
+{
+ struct digest_list_item_ref *ref = (struct digest_list_item_ref *)v;
+ struct digest_list_item *digest_list = ref->digest_list;
+ struct compact_list_hdr *hdr = get_hdr_ref(ref);
+
+ if (!ref->digest_offset) {
+ seq_printf(m, "%s (actions: %d): type: %d, size: %lld\n",
+ digest_list->label, digest_list->actions,
+ COMPACT_DIGEST_LIST, digest_list->size);
+ return 0;
+ }
+
+ seq_printf(m,
+ "%s (actions: %d): version: %d, algo: %s, type: %d, modifiers: %d, count: %d, datalen: %d\n",
+ digest_list->label, digest_list->actions, hdr->version,
+ hash_algo_name[hdr->algo], hdr->type, hdr->modifiers,
+ hdr->count, hdr->datalen);
+ return 0;
+}
+
static int digest_list_get_secfs_files(char *label, u8 *digest,
enum hash_algo algo, enum ops op,
struct dentry **dentry,
@@ -538,6 +624,67 @@ static const struct file_operations digest_label_ops = {
.llseek = generic_file_llseek,
};
+static const struct seq_operations digest_query_seqops = {
+ .start = digest_query_start,
+ .next = digest_query_next,
+ .stop = digest_query_stop,
+ .show = digest_query_show,
+};
+
+/*
+ * digest_query_open: sequentialize access to the add/del/query files
+ */
+static int digest_query_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(0, &flags))
+ return -EBUSY;
+
+ if (file->f_flags & O_WRONLY)
+ return 0;
+
+ return seq_open(file, &digest_query_seqops);
+}
+
+/*
+ * digest_query_write: write digest query (<algo>-<digest>).
+ */
+static ssize_t digest_query_write(struct file *file, const char __user *buf,
+ size_t datalen, loff_t *ppos)
+{
+ int rc;
+
+ if (datalen >= sizeof(digest_query))
+ return -EINVAL;
+
+ rc = copy_from_user(digest_query, buf, datalen);
+ if (rc)
+ return -EFAULT;
+
+ digest_query[datalen] = '\0';
+ return datalen;
+}
+
+/*
+ * digest_query_release - release the query file
+ */
+static int digest_query_release(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &flags);
+
+ if (file->f_flags & O_WRONLY)
+ return 0;
+
+ return seq_release(inode, file);
+}
+
+static const struct file_operations digest_query_ops = {
+ .open = digest_query_open,
+ .write = digest_query_write,
+ .read = seq_read,
+ .release = digest_query_release,
+ .llseek = generic_file_llseek,
+};
+
static int __init diglim_fs_init(void)
{
diglim_dir = securityfs_create_dir("diglim", integrity_dir);
@@ -567,8 +714,15 @@ static int __init diglim_fs_init(void)
if (IS_ERR(digest_label_dentry))
goto out;
+ digest_query_dentry = securityfs_create_file("digest_query", 0600,
+ diglim_dir, NULL,
+ &digest_query_ops);
+ if (IS_ERR(digest_query_dentry))
+ goto out;
+
return 0;
out:
+ securityfs_remove(digest_query_dentry);
securityfs_remove(digest_label_dentry);
securityfs_remove(digest_list_del_dentry);
securityfs_remove(digest_list_add_dentry);
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 03/12] diglim: Objects
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Define the objects to manage digest lists:
- digest_list_item: a digest list loaded into the kernel;
- digest_list_item_ref: a reference to a digest list;
- digest_item: a digest of a digest list.
Also define some helpers for the objects. More information can be found in
Documentation/security/diglim/implementation.rst.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
.../security/diglim/implementation.rst | 105 ++++++++++++++
MAINTAINERS | 1 +
security/integrity/diglim/diglim.h | 134 ++++++++++++++++++
3 files changed, 240 insertions(+)
create mode 100644 security/integrity/diglim/diglim.h
diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst
index 59a180b3bb3f..6002049612a1 100644
--- a/Documentation/security/diglim/implementation.rst
+++ b/Documentation/security/diglim/implementation.rst
@@ -95,3 +95,108 @@ with digest lists:
- ``DIGEST_LIST_ADD``: the digest list is being added;
- ``DIGEST_LIST_DEL``: the digest list is being deleted.
+
+
+Objects
+-------
+
+This section defines the objects to manage digest lists.
+
+.. kernel-doc:: security/integrity/diglim/diglim.h
+
+They are represented in the following class diagram:
+
+::
+
+ digest_offset,
+ hdr_offset---------------+
+ |
+ |
+ +------------------+ | +----------------------+
+ | digest_list_item |--- N:1 ---| digest_list_item_ref |
+ +------------------+ +----------------------+
+ |
+ 1:N
+ |
+ +-------------+
+ | digest_item |
+ +-------------+
+
+A ``digest_list_item`` is associated to one or multiple
+``digest_list_item_ref``, one for each digest it contains. However,
+a ``digest_list_item_ref`` is associated to only one ``digest_list_item``,
+as it represents a single location within a specific digest list.
+
+Given that a ``digest_list_item_ref`` represents a single location, it is
+associated to only one ``digest_item``. However, a ``digest_item`` can have
+multiple references (as it might appears multiple times within the same
+digest list or in different digest lists, if it is duplicated).
+
+All digest list references are stored for a given digest, so that a query
+result can include the OR of the modifiers and actions of each referenced
+digest list.
+
+The relationship between the described objects can be graphically
+represented as:
+
+::
+
+ Hash table +-------------+ +-------------+
+ PARSER +-----+ | digest_item | | digest_item |
+ FILE | key |-->| |-->...-->| |
+ METADATA +-----+ |ref0|...|refN| |ref0|...|refN|
+ +-------------+ +-------------+
+ ref0: | | refN:
+ digest_offset | +-----------------------------+ digest_offset
+ hdr_offset | | hdr_offset
+ | |
+ V V
+ +--------------------+
+ | digest_list_item |
+ | |
+ | size, buf, actions |
+ +--------------------+
+ ^
+ |
+ Hash table +-------------+ +-------------+
+ DIGEST_LIST +-----+ |ref0 | |ref0 |
+ | key |-->| |-->...-->| |
+ +-----+ | digest_item | | digest_item |
+ +-------------+ +-------------+
+
+The reference for the digest of the digest list differs from the references
+for the other digest types. ``digest_offset`` and ``hdr_offset`` are set to
+zero, so that the digest of the digest list is retrieved from the
+``digest_list_item`` structure directly (see ``get_digest()`` below).
+
+Finally, this section defines useful helpers to access a digest or the
+header the digest belongs to. For example:
+
+::
+
+ static inline struct compact_list_hdr *get_hdr(
+ struct digest_list_item *digest_list,
+ loff_t hdr_offset)
+ {
+ return (struct compact_list_hdr *)(digest_list->buf + hdr_offset);
+ }
+
+the header can be obtained by summing the address of the digest list buffer
+in the ``digest_list_item`` structure with ``hdr_offset``.
+
+Similarly:
+
+::
+
+ static inline u8 *get_digest(struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset)
+ {
+ /* Digest list digest is stored in a different place. */
+ if (!digest_offset)
+ return digest_list->digest;
+ return digest_list->buf + digest_offset;
+ }
+
+the digest can be obtained by summing the address of the digest list buffer
+with ``digest_offset`` (except for the digest lists, where the digest is
+stored in the ``digest`` field of the ``digest_list_item`` structure).
diff --git a/MAINTAINERS b/MAINTAINERS
index f61f5239468a..f7592d41367d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5462,6 +5462,7 @@ F: Documentation/security/diglim/implementation.rst
F: Documentation/security/diglim/index.rst
F: Documentation/security/diglim/introduction.rst
F: include/uapi/linux/diglim.h
+F: security/integrity/diglim/diglim.h
DIOLAN U2C-12 I2C DRIVER
M: Guenter Roeck <linux@roeck-us.net>
diff --git a/security/integrity/diglim/diglim.h b/security/integrity/diglim/diglim.h
new file mode 100644
index 000000000000..578253d7e1d1
--- /dev/null
+++ b/security/integrity/diglim/diglim.h
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Definitions only used inside DIGLIM.
+ */
+
+#ifndef __DIGLIM_INTERNAL_H
+#define __DIGLIM_INTERNAL_H
+
+#include <linux/types.h>
+#include <linux/crypto.h>
+#include <linux/fs.h>
+#include <linux/security.h>
+#include <linux/hash.h>
+#include <linux/tpm.h>
+#include <linux/audit.h>
+#include <crypto/hash_info.h>
+#include <linux/hash_info.h>
+#include <uapi/linux/diglim.h>
+
+#define MAX_DIGEST_SIZE 64
+#define HASH_BITS 10
+#define DIGLIM_HTABLE_SIZE (1 << HASH_BITS)
+
+/**
+ * struct digest_list_item - a digest list loaded into the kernel
+ *
+ * @size: size of the digest list buffer
+ * @buf: digest list buffer
+ * @digest: digest of the digest list
+ * @label: label used to identify the digest list (e.g. file name)
+ * @actions: actions performed on the digest list
+ * @algo: digest algorithm
+ */
+struct digest_list_item {
+ loff_t size;
+ u8 *buf;
+ u8 digest[64];
+ const char *label;
+ u8 actions;
+ enum hash_algo algo;
+};
+
+/**
+ * struct digest_list_item_ref - a reference to a digest list
+ *
+ * @list: linked list pointers
+ * @digest_list: pointer to struct digest_list_item
+ * @digest_offset: offset of the digest in the referenced digest list
+ * @hdr_offset: offset of the header the digest refers to in the digest list
+ */
+struct digest_list_item_ref {
+ struct list_head list;
+ struct digest_list_item *digest_list;
+ u32 digest_offset;
+ u32 hdr_offset;
+};
+
+/**
+ * struct digest_item - a digest of a digest list
+ *
+ * @hnext: pointers of the hash table
+ * @refs: linked list of struct digest_list_item_ref
+ */
+struct digest_item {
+ struct hlist_node hnext;
+ struct list_head refs;
+};
+
+struct h_table {
+ unsigned long len;
+ struct hlist_head queue[DIGLIM_HTABLE_SIZE];
+};
+
+static inline unsigned int hash_key(u8 *digest)
+{
+ return (digest[0] | digest[1] << 8) % DIGLIM_HTABLE_SIZE;
+}
+
+static inline struct compact_list_hdr *get_hdr(
+ struct digest_list_item *digest_list,
+ loff_t hdr_offset)
+{
+ return (struct compact_list_hdr *)(digest_list->buf + hdr_offset);
+}
+
+static inline enum hash_algo get_algo(struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset)
+{
+ /* Digest list digest algorithm is stored in a different place. */
+ if (!digest_offset)
+ return digest_list->algo;
+
+ return get_hdr(digest_list, hdr_offset)->algo;
+}
+
+static inline u8 *get_digest(struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset)
+{
+ /* Digest list digest is stored in a different place. */
+ if (!digest_offset)
+ return digest_list->digest;
+
+ return digest_list->buf + digest_offset;
+}
+
+static inline struct compact_list_hdr *get_hdr_ref(
+ struct digest_list_item_ref *ref)
+{
+ return get_hdr(ref->digest_list, ref->hdr_offset);
+}
+
+static inline enum hash_algo get_algo_ref(struct digest_list_item_ref *ref)
+{
+ /* Digest list digest algorithm is stored in a different place. */
+ if (!ref->digest_offset)
+ return ref->digest_list->algo;
+
+ return get_hdr_ref(ref)->algo;
+}
+
+static inline u8 *get_digest_ref(struct digest_list_item_ref *ref)
+{
+ /* Digest list digest is stored in a different place. */
+ if (!ref->digest_offset)
+ return ref->digest_list->digest;
+
+ return ref->digest_list->buf + ref->digest_offset;
+}
+#endif /*__DIGLIM_INTERNAL_H*/
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 08/12] diglim: Interfaces - digest_label
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the digest_label interface. It can be used to set a label to be
applied to the next digest list (buffer) loaded through digest_list_add.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
security/integrity/diglim/fs.c | 40 ++++++++++++++++++++++++++++++++++
1 file changed, 40 insertions(+)
diff --git a/security/integrity/diglim/fs.c b/security/integrity/diglim/fs.c
index caf2923c9146..8958e987f708 100644
--- a/security/integrity/diglim/fs.c
+++ b/security/integrity/diglim/fs.c
@@ -36,6 +36,13 @@ static struct dentry *diglim_dir;
* removed.
*/
static struct dentry *digest_lists_loaded_dir;
+/**
+ * DOC: digest_label
+ *
+ * digest_label can be used to set a label to be applied to the next digest
+ * list (buffer) loaded through digest_list_add.
+ */
+static struct dentry *digest_label_dentry;
/**
* DOC: digest_list_add
*
@@ -505,6 +512,32 @@ static const struct file_operations digest_list_upload_ops = {
.llseek = generic_file_llseek,
};
+/*
+ * digest_label_write: write label for next uploaded digest list.
+ */
+static ssize_t digest_label_write(struct file *file, const char __user *buf,
+ size_t datalen, loff_t *ppos)
+{
+ int rc;
+
+ if (datalen >= sizeof(digest_label))
+ return -EINVAL;
+
+ rc = copy_from_user(digest_label, buf, datalen);
+ if (rc)
+ return -EFAULT;
+
+ digest_label[datalen] = '\0';
+ return datalen;
+}
+
+static const struct file_operations digest_label_ops = {
+ .open = generic_file_open,
+ .write = digest_label_write,
+ .read = seq_read,
+ .llseek = generic_file_llseek,
+};
+
static int __init diglim_fs_init(void)
{
diglim_dir = securityfs_create_dir("diglim", integrity_dir);
@@ -528,8 +561,15 @@ static int __init diglim_fs_init(void)
if (IS_ERR(digest_list_del_dentry))
goto out;
+ digest_label_dentry = securityfs_create_file("digest_label", 0600,
+ diglim_dir, NULL,
+ &digest_label_ops);
+ if (IS_ERR(digest_label_dentry))
+ goto out;
+
return 0;
out:
+ securityfs_remove(digest_label_dentry);
securityfs_remove(digest_list_del_dentry);
securityfs_remove(digest_list_add_dentry);
securityfs_remove(digest_lists_loaded_dir);
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 04/12] diglim: Methods
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the methods requires to manage the three objects defined.
- digest_item methods:
- digest_add()
- digest_del()
- __digest_lookup()
- diglim_digest_get_info()
- digest_list_item_ref methods:
- digest_list_ref_add()
- digest_list_ref_del()
- digest_list_item methods:
- digest_list_add()
- digest_list_del()
More information about these functions can be found in
Documentation/security/diglim/implementation.rst.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
.../security/diglim/implementation.rst | 9 +
MAINTAINERS | 2 +
include/linux/diglim.h | 28 +
security/integrity/Kconfig | 1 +
security/integrity/Makefile | 1 +
security/integrity/diglim/Kconfig | 11 +
security/integrity/diglim/Makefile | 8 +
security/integrity/diglim/diglim.h | 20 +-
security/integrity/diglim/methods.c | 499 ++++++++++++++++++
9 files changed, 578 insertions(+), 1 deletion(-)
create mode 100644 include/linux/diglim.h
create mode 100644 security/integrity/diglim/Kconfig
create mode 100644 security/integrity/diglim/Makefile
create mode 100644 security/integrity/diglim/methods.c
diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst
index 6002049612a1..54af23b2f5f1 100644
--- a/Documentation/security/diglim/implementation.rst
+++ b/Documentation/security/diglim/implementation.rst
@@ -200,3 +200,12 @@ Similarly:
the digest can be obtained by summing the address of the digest list buffer
with ``digest_offset`` (except for the digest lists, where the digest is
stored in the ``digest`` field of the ``digest_list_item`` structure).
+
+
+Methods
+-------
+
+This section introduces the methods requires to manage the three objects
+defined.
+
+.. kernel-doc:: security/integrity/diglim/methods.c
diff --git a/MAINTAINERS b/MAINTAINERS
index f7592d41367d..9e085a36654a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5461,8 +5461,10 @@ F: Documentation/security/diglim/architecture.rst
F: Documentation/security/diglim/implementation.rst
F: Documentation/security/diglim/index.rst
F: Documentation/security/diglim/introduction.rst
+F: include/linux/diglim.h
F: include/uapi/linux/diglim.h
F: security/integrity/diglim/diglim.h
+F: security/integrity/diglim/methods.c
DIOLAN U2C-12 I2C DRIVER
M: Guenter Roeck <linux@roeck-us.net>
diff --git a/include/linux/diglim.h b/include/linux/diglim.h
new file mode 100644
index 000000000000..d4b4548a288b
--- /dev/null
+++ b/include/linux/diglim.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * DIGLIM functions available for use by kernel subsystems.
+ */
+
+#ifndef __DIGLIM_H
+#define __DIGLIM_H
+
+#include <crypto/hash_info.h>
+#include <uapi/linux/diglim.h>
+
+#ifdef CONFIG_DIGLIM
+extern int diglim_digest_get_info(u8 *digest, enum hash_algo algo,
+ enum compact_types type, u16 *modifiers,
+ u8 *actions);
+#else
+static inline int diglim_digest_get_info(u8 *digest, enum hash_algo algo,
+ enum compact_types type,
+ u16 *modifiers, u8 *actions)
+{
+ return -ENOENT;
+}
+#endif /*CONFIG_DIGLIM*/
+#endif /*__DIGLIM_H*/
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 71f0177e8716..8f94f4dcc052 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -98,5 +98,6 @@ config INTEGRITY_AUDIT
source "security/integrity/ima/Kconfig"
source "security/integrity/evm/Kconfig"
+source "security/integrity/diglim/Kconfig"
endif # if INTEGRITY
diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index 7ee39d66cf16..d6166550a6b8 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -19,3 +19,4 @@ integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \
platform_certs/keyring_handler.o
obj-$(CONFIG_IMA) += ima/
obj-$(CONFIG_EVM) += evm/
+obj-$(CONFIG_DIGLIM) += diglim/
diff --git a/security/integrity/diglim/Kconfig b/security/integrity/diglim/Kconfig
new file mode 100644
index 000000000000..436a76a14337
--- /dev/null
+++ b/security/integrity/diglim/Kconfig
@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Digest Lists Integrity Module (DIGLIM)
+#
+config DIGLIM
+ bool "Digest Lists Integrity Module (DIGLIM)"
+ select SECURITYFS
+ select CRYPTO
+ select CRYPTO_HASH_INFO
+ help
+ DIGLIM provides reference values for file content and metadata,
+ that can be used for measurement and appraisal with IMA.
diff --git a/security/integrity/diglim/Makefile b/security/integrity/diglim/Makefile
new file mode 100644
index 000000000000..b761ed8cfb3e
--- /dev/null
+++ b/security/integrity/diglim/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for building Digest Lists Integrity Module (DIGLIM).
+#
+
+obj-$(CONFIG_DIGLIM) += diglim.o
+
+diglim-y := methods.o
diff --git a/security/integrity/diglim/diglim.h b/security/integrity/diglim/diglim.h
index 578253d7e1d1..25851e7d4906 100644
--- a/security/integrity/diglim/diglim.h
+++ b/security/integrity/diglim/diglim.h
@@ -20,7 +20,7 @@
#include <linux/audit.h>
#include <crypto/hash_info.h>
#include <linux/hash_info.h>
-#include <uapi/linux/diglim.h>
+#include <linux/diglim.h>
#define MAX_DIGEST_SIZE 64
#define HASH_BITS 10
@@ -81,6 +81,8 @@ static inline unsigned int hash_key(u8 *digest)
return (digest[0] | digest[1] << 8) % DIGLIM_HTABLE_SIZE;
}
+extern struct h_table htable[COMPACT__LAST];
+
static inline struct compact_list_hdr *get_hdr(
struct digest_list_item *digest_list,
loff_t hdr_offset)
@@ -131,4 +133,20 @@ static inline u8 *get_digest_ref(struct digest_list_item_ref *ref)
return ref->digest_list->buf + ref->digest_offset;
}
+
+struct digest_item *__digest_lookup(u8 *digest, enum hash_algo algo,
+ enum compact_types type, u16 *modifiers,
+ u8 *actions);
+struct digest_item *digest_add(u8 *digest, enum hash_algo algo,
+ enum compact_types type,
+ struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset);
+void digest_del(u8 *digest, enum hash_algo algo, enum compact_types type,
+ struct digest_list_item *digest_list, loff_t digest_offset,
+ loff_t hdr_offset);
+struct digest_item *digest_list_add(u8 *digest, enum hash_algo algo,
+ loff_t size, u8 *buf, u8 actions,
+ const char *label);
+void digest_list_del(u8 *digest, enum hash_algo algo, u8 actions,
+ struct digest_list_item *digest_list);
#endif /*__DIGLIM_INTERNAL_H*/
diff --git a/security/integrity/diglim/methods.c b/security/integrity/diglim/methods.c
new file mode 100644
index 000000000000..7ed61399cfe8
--- /dev/null
+++ b/security/integrity/diglim/methods.c
@@ -0,0 +1,499 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2005,2006,2007,2008 IBM Corporation
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * Functions to manage digest lists.
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/module.h>
+#include <linux/fault-inject.h>
+
+#include "diglim.h"
+#include "../integrity.h"
+
+/* Define a cache for each object type. */
+static struct kmem_cache *digest_list_item_cache __read_mostly;
+static struct kmem_cache *digest_list_item_ref_cache __read_mostly;
+static struct kmem_cache *digest_item_cache __read_mostly;
+
+/* Define a hash table for each digest type. */
+struct h_table htable[COMPACT__LAST] = {{
+ .queue[0 ... DIGLIM_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
+}};
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+static DECLARE_FAULT_ATTR(fail_diglim);
+
+static int __init fail_diglim_debugfs(void)
+{
+ struct dentry *dir = fault_create_debugfs_attr("fail_diglim", NULL,
+ &fail_diglim);
+
+ return PTR_ERR_OR_ZERO(dir);
+}
+
+static inline bool should_fail_diglim(void)
+{
+ return should_fail(&fail_diglim, 1);
+}
+
+late_initcall(fail_diglim_debugfs);
+#else
+static inline bool should_fail_diglim(void)
+{
+ return false;
+}
+#endif
+
+/**
+ * __digest_lookup - lookup digest and return associated modifiers and actions
+ * @digest: digest to lookup
+ * @algo: digest algorithm
+ * @type: type of digest to lookup (e.g. file, metadata)
+ * @modifiers: modifiers (attributes) associated to the found digest
+ * @actions: actions performed by IMA on the digest list containing the digest
+ *
+ * This function searches the given digest in the hash table depending on the
+ * passed type and sets the modifiers and actions associated to the digest, if
+ * the pointers are not NULL.
+ *
+ * This function is not intended for external use, as the returned digest item
+ * could be freed at any time after it has been returned.
+ * diglim_digest_get_info() should be used instead by external callers, as it
+ * only returns the modifiers and the actions associated to the digest at the
+ * time the digest is searched.
+ *
+ * RCU protects both the hash table and the linked list of references to the
+ * digest lists containing the found digest.
+ *
+ * Return: a digest_item structure if the digest is found, NULL otherwise.
+ */
+struct digest_item *__digest_lookup(u8 *digest, enum hash_algo algo,
+ enum compact_types type, u16 *modifiers,
+ u8 *actions)
+{
+ struct digest_item *d = NULL;
+ struct digest_list_item_ref *ref;
+ int digest_len = hash_digest_size[algo];
+ unsigned int key = hash_key(digest);
+ bool found = false;
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(d, &htable[type].queue[key], hnext) {
+ list_for_each_entry_rcu(ref, &d->refs, list) {
+ if (get_algo_ref(ref) != algo ||
+ memcmp(get_digest_ref(ref), digest, digest_len))
+ break;
+
+ found = true;
+
+ /* There is no need to scan all digest list refs. */
+ if (!modifiers || !actions)
+ break;
+
+ /*
+ * The resulting modifiers and actions are the OR of the
+ * modifiers and actions for each digest list.
+ */
+ *modifiers |= get_hdr_ref(ref)->modifiers;
+ *actions |= ref->digest_list->actions;
+ }
+
+ if (found)
+ break;
+ }
+
+ rcu_read_unlock();
+ return d;
+}
+
+/**
+ * diglim_digest_get_info - lookup digest and return modifiers and actions
+ * @digest: digest to lookup
+ * @algo: digest algorithm
+ * @type: type of digest to lookup (e.g. file, metadata)
+ * @modifiers: modifiers (attributes) associated to the found digest
+ * @actions: actions performed by IMA on the digest lists containing the digest
+ *
+ * This function searches the given digest in the hash table depending on the
+ * passed type and sets the modifiers and actions associated to the digest, if
+ * the pointers are not NULL.
+ *
+ * This function is safe for external use, as it does not return pointers of
+ * objects that can be freed without the caller notices it.
+ *
+ * Return: 0 if the digest is found, -ENOENT otherwise.
+ */
+int diglim_digest_get_info(u8 *digest, enum hash_algo algo,
+ enum compact_types type, u16 *modifiers, u8 *actions)
+{
+ struct digest_item *d;
+
+ d = __digest_lookup(digest, algo, type, modifiers, actions);
+ if (!d)
+ return -ENOENT;
+
+ return 0;
+}
+
+/**
+ * digest_list_ref_add - add reference to a digest list
+ * @d: digest a new reference is added to
+ * @digest_list: digest list whose reference is being added
+ * @digest_offset: offset of the digest in the buffer of the digest list
+ * @hdr_offset: offset of the header within the digest list the digest refers to
+ *
+ * This function adds a new reference to an existing digest list for a given
+ * digest. The reference is described by the digest_list_item_ref structure and
+ * consists of a pointer of the digest list, the offset of the digest to the
+ * beginning of the digest list buffer and the offset of the header the digest
+ * refers to (each digest list might be composed of several digest blocks, each
+ * prefixed by a header describing the attributes of those digests).
+ *
+ * Return: 0 if a new digest list reference was successfully added, a negative
+ * value otherwise.
+ */
+static int digest_list_ref_add(struct digest_item *d,
+ struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset)
+{
+ struct digest_list_item_ref *new_ref = NULL;
+ u8 *digest = get_digest(digest_list, digest_offset, hdr_offset);
+ enum hash_algo algo = get_algo(digest_list, digest_offset, hdr_offset);
+ int digest_len = hash_digest_size[algo];
+
+ /* Allocate a new reference. */
+ if (!should_fail_diglim())
+ new_ref = kmem_cache_alloc(digest_list_item_ref_cache,
+ GFP_KERNEL);
+ if (!new_ref) {
+ print_hex_dump(KERN_ERR, "digest list ref allocation failed: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ return -ENOMEM;
+ }
+
+ /* Set the new reference. */
+ new_ref->digest_list = digest_list;
+ /* Converting loff_t -> u32 is fine as long as the digest list < 4G. */
+ new_ref->digest_offset = digest_offset;
+ new_ref->hdr_offset = hdr_offset;
+
+ list_add_tail_rcu(&new_ref->list, &d->refs);
+
+ print_hex_dump_debug("add digest list ref: ", DUMP_PREFIX_NONE,
+ digest_len, 1, digest, digest_len, true);
+ return 0;
+}
+
+/**
+ * digest_list_ref_del - del reference to a digest list
+ * @d: digest a reference is deleted from
+ * @digest_list: digest list whose reference is being deleted
+ * @digest_offset: offset of the digest in the buffer of the digest list
+ * @hdr_offset: offset of the header within the digest list the digest refers to
+ *
+ * This function searches the reference to an already loaded digest list in the
+ * linked list of references stored for each digest item. If the reference is
+ * found (if not, it is a bug), the function deletes it from the linked list.
+ */
+static void digest_list_ref_del(struct digest_item *d,
+ struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset)
+{
+ struct digest_list_item_ref *ref;
+ u8 *digest = get_digest(digest_list, digest_offset, hdr_offset);
+ enum hash_algo algo = get_algo(digest_list, digest_offset, hdr_offset);
+ int digest_len = hash_digest_size[algo];
+
+ /* Search for a digest list reference. */
+ list_for_each_entry(ref, &d->refs, list)
+ if (ref->digest_list == digest_list)
+ break;
+
+ if (!ref) {
+ print_hex_dump(KERN_ERR, "digest list ref not found: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ return;
+ }
+
+ list_del_rcu(&ref->list);
+ kmem_cache_free(digest_list_item_ref_cache, ref);
+
+ print_hex_dump_debug("del digest list ref: ", DUMP_PREFIX_NONE,
+ digest_len, 1, digest, digest_len, true);
+}
+
+/**
+ * digest_add - add a new digest
+ * @digest: digest in binary form
+ * @algo: digest algorithm
+ * @type: digest type
+ * @digest_list: digest list the new digest belongs to
+ * @digest_offset: offset of the digest in the buffer of the digest list
+ * @hdr_offset: offset of the header within the digest list the digest refers to
+ *
+ * This function first searches if the digest is already in the hash table for
+ * the given type. The digest is searched by comparing the passed digest and
+ * algorithm with the digest obtained from the first digest list reference
+ * (buffer + digest_offset), or from the digest field of a digest list item,
+ * for a digest list.
+ *
+ * If the digest exists, only a new reference is added (there might be multiple
+ * references to the same digest list).
+ *
+ * If the digest is not found, a new digest item is allocated and a reference to
+ * the passed digest list is added to that item. The digest item is finally
+ * added to the hash table for the given type.
+ *
+ * Proper locking must be provided by the caller.
+ *
+ * Return: a new or the found digest item on success, an error pointer
+ * otherwise.
+ */
+struct digest_item *digest_add(u8 *digest, enum hash_algo algo,
+ enum compact_types type,
+ struct digest_list_item *digest_list,
+ loff_t digest_offset, loff_t hdr_offset)
+{
+ int digest_len = hash_digest_size[algo];
+ struct digest_item *d;
+ int ret;
+
+ /* Search the digest. */
+ d = __digest_lookup(digest, algo, type, NULL, NULL);
+ if (d) {
+ /*
+ * Add a new digest list reference to the existing digest item.
+ */
+ ret = digest_list_ref_add(d, digest_list, digest_offset,
+ hdr_offset);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ print_hex_dump_debug("digest add duplicate: ", DUMP_PREFIX_NONE,
+ digest_len, 1, digest, digest_len, true);
+ return d;
+ }
+
+ /* Allocate a new digest item. */
+ if (!should_fail_diglim())
+ d = kmem_cache_alloc(digest_item_cache, GFP_KERNEL);
+ if (!d) {
+ print_hex_dump_debug("digest allocation failed: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ INIT_LIST_HEAD(&d->refs);
+
+ /* Add a new digest list reference to the new digest item. */
+ ret = digest_list_ref_add(d, digest_list, digest_offset, hdr_offset);
+ if (ret < 0) {
+ kmem_cache_free(digest_item_cache, d);
+ return ERR_PTR(ret);
+ }
+
+ /* Add the new digest item to the hash table for the given type. */
+ hlist_add_head_rcu(&d->hnext, &htable[type].queue[hash_key(digest)]);
+ htable[type].len++;
+
+ print_hex_dump_debug("digest add: ", DUMP_PREFIX_NONE, digest_len, 1,
+ digest, digest_len, true);
+ return d;
+}
+
+/**
+ * digest_del - delete a digest with one reference, or just a reference
+ * @digest: digest in binary form
+ * @algo: digest algorithm
+ * @type: digest type
+ * @digest_list: digest list the digest belongs to
+ * @digest_offset: offset of the digest in the buffer of the digest list
+ * @hdr_offset: offset of the header within the digest list the digest refers to
+ *
+ * This function is called when a digest list is being removed. The digest is
+ * first searched in the hash table for the given type. If it is found (if not,
+ * it is a bug, because digest lists can be deleted only if they were added
+ * previously), a reference of the passed digest list is deleted from the linked
+ * list of references of the digest item.
+ *
+ * If the last reference was deleted, the digest item is also deleted and
+ * removed from the hash table.
+ *
+ * Proper locking must be provided by the caller.
+ */
+void digest_del(u8 *digest, enum hash_algo algo, enum compact_types type,
+ struct digest_list_item *digest_list, loff_t digest_offset,
+ loff_t hdr_offset)
+{
+ struct digest_item *d;
+ int digest_len = hash_digest_size[algo];
+
+ /* Search the digest. */
+ d = __digest_lookup(digest, algo, type, NULL, NULL);
+ if (!d) {
+ print_hex_dump(KERN_ERR, "digest not found: ", DUMP_PREFIX_NONE,
+ digest_len, 1, digest, digest_len, true);
+ return;
+ }
+
+ /* Delete a reference of the passed digest list. */
+ digest_list_ref_del(d, digest_list, digest_offset, hdr_offset);
+
+ print_hex_dump_debug(!list_empty(&d->refs) ?
+ "digest del duplicate: " : "digest del: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+
+ /* Return if there are still references. */
+ if (!list_empty(&d->refs))
+ return;
+
+ /*
+ * Remove the digest item from the hash table and free it if there are
+ * no more references left.
+ */
+ hlist_del_rcu(&d->hnext);
+ htable[type].len--;
+ kmem_cache_free(digest_item_cache, d);
+}
+
+/**
+ * digest_list_add - add a new digest list
+ * @digest: digest of the digest list in binary form
+ * @algo: digest algorithm
+ * @size: digest list size
+ * @buf: digest list buffer
+ * @actions: actions (measure/appraise) performed by IMA on the digest list
+ * @label: label to be used to identify the digest list
+ *
+ * This function allocates a new digest list item, which contains the buffer,
+ * size, actions performed by IMA and a label. Each digest list item is
+ * associated to a digest item representing the digest of the digest list.
+ *
+ * This function prevents the same digest list to be added multiple times by
+ * searching its digest in the hash table for the COMPACT_DIGEST_LIST type.
+ *
+ * The passed buffer is copied in a new memory area, to avoid to reference
+ * memory that could be freed by the caller.
+ *
+ * If allocation of a new digest list and the associated buffer was successful,
+ * its digest is added to the hash table for the COMPACT_DIGEST_LIST type.
+ *
+ * Proper locking must be provided by the caller.
+ *
+ * Return: the digest item associated to the digest list item on success, an
+ * error pointer otherwise.
+ */
+struct digest_item *digest_list_add(u8 *digest, enum hash_algo algo,
+ loff_t size, u8 *buf, u8 actions,
+ const char *label)
+{
+ struct digest_item *d;
+ struct digest_list_item *digest_list = NULL;
+ int digest_len = hash_digest_size[algo];
+
+ /* Search the digest of the digest list. */
+ d = __digest_lookup(digest, algo, COMPACT_DIGEST_LIST, NULL, NULL);
+ if (d) {
+ print_hex_dump(KERN_ERR, "digest list already uploaded: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ return ERR_PTR(-EEXIST);
+ }
+
+ /* Allocate a new digest list. */
+ if (!should_fail_diglim())
+ digest_list = kmem_cache_alloc(digest_list_item_cache,
+ GFP_KERNEL);
+ if (!digest_list) {
+ print_hex_dump(KERN_ERR, "digest list allocation failed: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ digest_list->buf = NULL;
+ digest_list->size = size;
+
+ if (!should_fail_diglim())
+ digest_list->buf = kmemdup(buf, size, GFP_KERNEL);
+ if (!digest_list->buf) {
+ print_hex_dump(KERN_ERR, "digest list allocation failed: ",
+ DUMP_PREFIX_NONE, digest_len, 1, digest,
+ digest_len, true);
+ kmem_cache_free(digest_list_item_cache, digest_list);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ digest_list->actions = actions;
+ memcpy(digest_list->digest, digest, hash_digest_size[algo]);
+ digest_list->algo = algo;
+ digest_list->label = label;
+
+ /* Add the digest of the digest list to the hash table. */
+ d = digest_add(digest, algo, COMPACT_DIGEST_LIST, digest_list, 0, 0);
+ if (IS_ERR(d)) {
+ kfree(digest_list->buf);
+ kmem_cache_free(digest_list_item_cache, digest_list);
+ }
+
+ return d;
+}
+
+/**
+ * digest_list_del - delete an existing digest list
+ * @digest: digest of the digest list in binary form
+ * @algo: digest algorithm
+ * @actions: actions (measure/appraise) performed by IMA on the digest list
+ * @digest_list: digest list to delete
+ *
+ * This function searches the digest of the digest list in the hash table for
+ * the COMPACT_DIGEST_LIST type. If it is found, this function frees the buffer
+ * and the digest list item allocated in digest_list_add().
+ *
+ * This function will be executed only for digest lists that were previously
+ * added.
+ *
+ * Proper locking must be provided by the caller.
+ */
+void digest_list_del(u8 *digest, enum hash_algo algo, u8 actions,
+ struct digest_list_item *digest_list)
+{
+ /* Delete the digest item associated to the digest list. */
+ digest_del(digest, algo, COMPACT_DIGEST_LIST, digest_list, 0, 0);
+
+ /*
+ * Free the buffer and the digest list item allocated when the digest
+ * list was added.
+ */
+ kfree(digest_list->buf);
+ kmem_cache_free(digest_list_item_cache, digest_list);
+}
+
+static int __init digest_list_cache_init(void)
+{
+ digest_list_item_cache = kmem_cache_create("digest_list_item_cache",
+ sizeof(struct digest_list_item),
+ 0, SLAB_PANIC, NULL);
+
+ digest_list_item_ref_cache = kmem_cache_create(
+ "digest_list_item_ref_cache",
+ sizeof(struct digest_list_item_ref), 0,
+ SLAB_PANIC, NULL);
+
+ digest_item_cache = kmem_cache_create("digest_item_cache",
+ sizeof(struct digest_item), 0,
+ SLAB_PANIC, NULL);
+
+ return 0;
+}
+
+late_initcall(digest_list_cache_init)
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 02/12] diglim: Basic definitions
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Introduce the basic definitions, exported to user space, to use digest
lists. The definitions, added to include/uapi/linux/diglim.h, are
documented in Documentation/security/diglim/implementation.rst.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
.../security/diglim/implementation.rst | 97 +++++++++++++++++++
Documentation/security/diglim/index.rst | 1 +
MAINTAINERS | 2 +
include/uapi/linux/diglim.h | 51 ++++++++++
4 files changed, 151 insertions(+)
create mode 100644 Documentation/security/diglim/implementation.rst
create mode 100644 include/uapi/linux/diglim.h
diff --git a/Documentation/security/diglim/implementation.rst b/Documentation/security/diglim/implementation.rst
new file mode 100644
index 000000000000..59a180b3bb3f
--- /dev/null
+++ b/Documentation/security/diglim/implementation.rst
@@ -0,0 +1,97 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Implementation
+==============
+
+This section describes the implementation of DIGLIM.
+
+
+Basic Definitions
+-----------------
+
+This section introduces the basic definitions required to use DIGLIM.
+
+
+Compact Digest List Format
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/uapi/linux/diglim.h
+ :identifiers: compact_list_hdr
+
+Compact Types
+.............
+
+Digests can be of different types:
+
+- ``COMPACT_PARSER``: digests of executables which are given the ability to
+ parse digest lists not in the compact format and to upload to the kernel
+ the digest list converted to the compact format;
+- ``COMPACT_FILE``: digests of regular files;
+- ``COMPACT_METADATA``: digests of file metadata (e.g. the digest
+ calculated by EVM to verify a portable signature);
+- ``COMPACT_DIGEST_LIST``: digests of digest lists (only used internally by
+ the kernel).
+
+Different users of DIGLIM might query digests with different compact types.
+For example, IMA would be interested in COMPACT_FILE, as it deals with
+regular files, while EVM would be interested in COMPACT_METADATA, as it
+verifies file metadata.
+
+
+Compact Modifiers
+.................
+
+Digests can also have specific attributes called modifiers (bit position):
+
+- ``COMPACT_MOD_IMMUTABLE``: file content or metadata should not be
+ modifiable.
+
+IMA might use this information to deny open for writing, or EVM to deny
+setxattr operations.
+
+
+Actions
+.......
+
+This section defines a set of possible actions that have been executed on
+the digest lists (bit position):
+
+- ``COMPACT_ACTION_IMA_MEASURED``: the digest list has been measured by
+ IMA;
+- ``COMPACT_ACTION_IMA_APPRAISED``: the digest list has been successfully
+ appraised by IMA;
+- ``COMPACT_ACTION_IMA_APPRAISED_DIGSIG``: the digest list has been
+ successfully appraised by IMA by verifying a digital signature.
+
+This information might help users of DIGLIM to decide whether to use the
+result of a queried digest.
+
+For example, if a digest belongs to a digest list that was not measured
+before, IMA should ignore the result of the query, as the measurement list
+sent to remote verifiers would lack which digests have been uploaded to the
+kernel.
+
+
+Compact Digest List Example
+...........................
+
+::
+
+ version: 1, type: 2, modifiers: 0 algo: 4, count: 3, datalen: 96
+ <SHA256 digest1><SHA256 digest2><SHA256 digest3>
+ version: 1, type: 3, modifiers: 1 algo: 6, count: 2, datalen: 128
+ <SHA512 digest1><SHA512 digest2>
+
+This digest list consists of two blocks. The first block contains three
+SHA256 digests of regular files. The second block contains two SHA512
+digests of immutable metadata.
+
+
+Compact Digest List Operations
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Finally, this section defines the possible operations that can be performed
+with digest lists:
+
+- ``DIGEST_LIST_ADD``: the digest list is being added;
+- ``DIGEST_LIST_DEL``: the digest list is being deleted.
diff --git a/Documentation/security/diglim/index.rst b/Documentation/security/diglim/index.rst
index 0fc5ab019bc0..4771134c2f0d 100644
--- a/Documentation/security/diglim/index.rst
+++ b/Documentation/security/diglim/index.rst
@@ -9,3 +9,4 @@ Digest Lists Integrity Module (DIGLIM)
introduction
architecture
+ implementation
diff --git a/MAINTAINERS b/MAINTAINERS
index c914dadd7e65..f61f5239468a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5458,8 +5458,10 @@ L: linux-integrity@vger.kernel.org
S: Supported
T: git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
F: Documentation/security/diglim/architecture.rst
+F: Documentation/security/diglim/implementation.rst
F: Documentation/security/diglim/index.rst
F: Documentation/security/diglim/introduction.rst
+F: include/uapi/linux/diglim.h
DIOLAN U2C-12 I2C DRIVER
M: Guenter Roeck <linux@roeck-us.net>
diff --git a/include/uapi/linux/diglim.h b/include/uapi/linux/diglim.h
new file mode 100644
index 000000000000..8a33d1f0fefb
--- /dev/null
+++ b/include/uapi/linux/diglim.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright (C) 2017-2021 Huawei Technologies Duesseldorf GmbH
+ *
+ * Author: Roberto Sassu <roberto.sassu@huawei.com>
+ *
+ * DIGLIM definitions exported to user space, useful for generating digest
+ * lists.
+ */
+
+#ifndef _UAPI__LINUX_DIGLIM_H
+#define _UAPI__LINUX_DIGLIM_H
+
+#include <linux/types.h>
+#include <linux/hash_info.h>
+
+enum compact_types { COMPACT_KEY, COMPACT_PARSER, COMPACT_FILE,
+ COMPACT_METADATA, COMPACT_DIGEST_LIST, COMPACT__LAST };
+
+enum compact_modifiers { COMPACT_MOD_IMMUTABLE, COMPACT_MOD__LAST };
+
+enum compact_actions { COMPACT_ACTION_IMA_MEASURED,
+ COMPACT_ACTION_IMA_APPRAISED,
+ COMPACT_ACTION_IMA_APPRAISED_DIGSIG,
+ COMPACT_ACTION__LAST };
+
+enum ops { DIGEST_LIST_ADD, DIGEST_LIST_DEL, DIGEST_LIST_OP__LAST };
+
+/**
+ * struct compact_list_hdr - header of the following concatenated digests
+ * @version: version of the digest list
+ * @_reserved: field reserved for future use
+ * @type: type of digest list among enum compact_types
+ * @modifiers: additional attributes among (1 << enum compact_modifiers)
+ * @algo: digest algorithm
+ * @count: number of digests
+ * @datalen: length of concatenated digests
+ *
+ * A digest list is a set of blocks composed by struct compact_list_hdr and
+ * the following concatenated digests.
+ */
+struct compact_list_hdr {
+ __u8 version;
+ __u8 _reserved;
+ __le16 type;
+ __le16 modifiers;
+ __le16 algo;
+ __le32 count;
+ __le32 datalen;
+} __packed;
+#endif /*_UAPI__LINUX_DIGLIM_H*/
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 01/12] diglim: Overview
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
In-Reply-To: <20210726163700.2092768-1-roberto.sassu@huawei.com>
Add an overview of DIGLIM to Documentation/security/diglim/introduction.rst
and the architecture to Documentation/security/diglim/architecture.rst
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
.../security/diglim/architecture.rst | 45 ++
Documentation/security/diglim/index.rst | 11 +
.../security/diglim/introduction.rst | 631 ++++++++++++++++++
Documentation/security/index.rst | 1 +
MAINTAINERS | 9 +
5 files changed, 697 insertions(+)
create mode 100644 Documentation/security/diglim/architecture.rst
create mode 100644 Documentation/security/diglim/index.rst
create mode 100644 Documentation/security/diglim/introduction.rst
diff --git a/Documentation/security/diglim/architecture.rst b/Documentation/security/diglim/architecture.rst
new file mode 100644
index 000000000000..a54fe2453715
--- /dev/null
+++ b/Documentation/security/diglim/architecture.rst
@@ -0,0 +1,45 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Architecture
+============
+
+This section introduces the high level architecture of DIGLIM.
+
+::
+
+ 5. add/delete from hash table and add refs to digest list
+ +---------------------------------------------+
+ | +-----+ +-------------+ +--+
+ | | key |-->| digest refs |-->...-->| |
+ V +-----+ +-------------+ +--+
+ +-------------+ +-----+ +-------------+
+ | digest list | | key |-->| digest refs |
+ | (compact) | +-----+ +-------------+
+ +-------------+ +-----+ +-------------+
+ ^ 4. copy to | key |-->| digest refs |
+ | kernel memory +-----+ +-------------+ kernel space
+ --------------------------------------------------------------------------
+ ^ ^ user space
+ |<----------------+ 3b. upload |
+ +-------------+ +------------+ | 6. query digest
+ | digest list | | user space | 2b. convert
+ | (compact) | | parser |
+ +-------------+ +------------+
+ 1a. upload ^ 1b. read
+ |
+ +------------+
+ | RPM header |
+ +------------+
+
+
+As mentioned before, digest lists can be uploaded directly if they are in
+the compact format (step 1a) or can be uploaded indirectly by the user
+space parser if they are in an alternative format (steps 1b-3b).
+
+During upload, the kernel makes a copy of the digest list to the kernel
+memory (step 4), and creates the necessary structures to index the digests
+(hash table and a linked list of digest list references to locate the
+digests in the digest list) (step 5).
+
+Finally, digests can be searched from user space through a securityfs file
+(step 6) or by the kernel itself.
diff --git a/Documentation/security/diglim/index.rst b/Documentation/security/diglim/index.rst
new file mode 100644
index 000000000000..0fc5ab019bc0
--- /dev/null
+++ b/Documentation/security/diglim/index.rst
@@ -0,0 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================================
+Digest Lists Integrity Module (DIGLIM)
+======================================
+
+.. toctree::
+ :maxdepth: 1
+
+ introduction
+ architecture
diff --git a/Documentation/security/diglim/introduction.rst b/Documentation/security/diglim/introduction.rst
new file mode 100644
index 000000000000..d8d8b2a17222
--- /dev/null
+++ b/Documentation/security/diglim/introduction.rst
@@ -0,0 +1,631 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Introduction
+============
+
+Digest Lists Integrity Module (DIGLIM) is a new component added to the
+integrity subsystem in the kernel, primarily aiming to aid Integrity
+Measurement Architecture (IMA) in the process of checking the integrity of
+file content and metadata. It accomplishes this task by storing reference
+values coming from software vendors and by reporting whether or not the
+digest of file content or metadata calculated by IMA (or EVM) is found
+among those values. In this way, IMA can decide, depending on the result of
+a query, if a measurement should be taken or access to the file should be
+granted. The `Security Assumptions`_ section explains more in detail why
+this component has been placed in the kernel.
+
+The main benefits of using IMA in conjunction with DIGLIM are the ability
+to implement advanced remote attestation schemes based on the usage of a
+TPM key for establishing a TLS secure channel [1][2], and to reduce the
+burden on Linux distribution vendors to extend secure boot at OS level to
+applications.
+
+DIGLIM does not have the complexity of feature-rich databases. In fact, its
+main functionality comes from the hash table primitives already in the
+kernel. It does not have an ad-hoc storage module, it just indexes data in
+a fixed format (digest lists, a set of concatenated digests preceded by a
+header), copied to kernel memory as they are. Lastly, it does not support
+database-oriented languages such as SQL, but only accepts a digest and its
+algorithm as a query.
+
+The only digest list format supported by DIGLIM is called ``compact``.
+However, Linux distribution vendors don't have to generate new digest lists
+in this format for the packages they release, as already available
+information, such as RPM headers and DEB package metadata, can be already
+used as a source for reference values (they already include file digests),
+with a user space parser taking care of the conversion to the compact
+format.
+
+Although one might perceive that storing file or metadata digests for a
+Linux distribution would significantly increase the memory usage, this does
+not seem to be the case. As an anticipation of the evaluation done in the
+`Preliminary Performance Evaluation`_ section, protecting binaries and
+shared libraries of a minimal Fedora 33 installation requires 208K of
+memory for the digest lists plus 556K for indexing.
+
+In exchange for a slightly increased memory usage, DIGLIM improves the
+performance of the integrity subsystem. In the considered scenario, IMA
+measurement and appraisal with digest lists requires respectively less than
+one quarter and less than half the time, compared to the current solution.
+
+DIGLIM also keeps track of whether digest lists have been processed in some
+way (e.g. measured or appraised by IMA). This is important for example for
+remote attestation, so that remote verifiers understand what has been
+uploaded to the kernel.
+
+DIGLIM behaves like a transactional database, i.e. it has the ability to
+roll back to the beginning of the transaction if an error occurred during
+the addition of a digest list (the deletion operation always succeeds).
+This capability has been tested with an ad-hoc fault injection mechanism
+capable of simulating failures during the operations.
+
+Finally, DIGLIM exposes to user space, through securityfs, the digest lists
+currently loaded, the number of digests added, a query interface and an
+interface to set digest list labels.
+
+[1] LSS EU 2019
+
+- slides:
+ https://static.sched.com/hosted_files/lsseu2019/bd/secure_attested_communication_channels_lss_eu_2019.pdf
+- video: https://youtu.be/mffdQgkvDNY
+
+[2] FutureTPM EU project, final review meeting demo
+
+- slides:
+ https://futuretpm.eu/images/07-3-FutureTPM-Final-Review-Slides-WP6-Device-Management-Use-Case-HWDU.pdf
+- video: https://vimeo.com/528251864/4c1d55abcd
+
+
+Binary Integrity
+----------------
+
+Integrity is a fundamental security property in information systems.
+Integrity could be described as the condition in which a generic
+component is just after it has been released by the entity that created it.
+
+One way to check whether a component is in this condition (called binary
+integrity) is to calculate its digest and to compare it with a reference
+value (i.e. the digest calculated in controlled conditions, when the
+component is released).
+
+IMA, a software part of the integrity subsystem, can perform such
+evaluation and execute different actions:
+
+- store the digest in an integrity-protected measurement list, so that it
+ can be sent to a remote verifier for analysis;
+- compare the calculated digest with a reference value (usually protected
+ with a signature) and deny operations if the file is found corrupted;
+- store the digest in the system log.
+
+
+Contribution
+------------
+
+DIGLIM further enhances the capabilities offered by IMA-based solutions
+and, at the same time, makes them more practical to adopt by reusing
+existing sources as reference values for integrity decisions.
+
+Possible sources for digest lists are:
+
+- RPM headers;
+- Debian repository metadata.
+
+
+Benefits for IMA Measurement
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+One of the issues that arises when files are measured by the OS is that,
+due to parallel execution, the order in which file accesses happen cannot
+be predicted. Since the TPM Platform Configuration Register (PCR) extend
+operation, executed after each file measurement, cryptographically binds
+the current measurement to the previous ones, the PCR value at the end of a
+workload cannot be predicted too.
+
+Thus, even if the usage of a TPM key, bound to a PCR value, should be
+allowed when only good files were accessed, the TPM could unexpectedly deny
+an operation on that key if files accesses did not happen as stated by the
+key policy (which allows only one of the possible sequences).
+
+DIGLIM solves this issue by making the PCR value stable over the time and
+not dependent on file accesses. The following figure depicts the current
+and the new approaches:
+
+::
+
+ IMA measurement list (current)
+
+ entry# 1st boot 2nd boot 3rd boot
+ +----+---------------+ +----+---------------+ +----+---------------+
+ 1: | 10 | file1 measur. | | 10 | file3 measur. | | 10 | file2 measur. |
+ +----+---------------+ +----+---------------+ +----+---------------+
+ 2: | 10 | file2 measur. | | 10 | file2 measur. | | 10 | file3 measur. |
+ +----+---------------+ +----+---------------+ +----+---------------+
+ 3: | 10 | file3 measur. | | 10 | file1 measur. | | 10 | file4 measur. |
+ +----+---------------+ +----+---------------+ +----+---------------+
+
+ PCR: Extend != Extend != Extend
+ file1, file2, file3 file3, file2, file1 file2, file3, file4
+
+
+ PCR Extend definition:
+
+ PCR(new value) = Hash(Hash(meas. entry), PCR(previous value))
+
+A new entry in the measurement list is created by IMA for each file access.
+Assuming that ``file1``, ``file2`` and ``file3`` are files provided by the
+software vendor, ``file4`` is an unknown file, the first two PCR values
+above represent a good system state, the third a bad system state. The PCR
+values are the result of the PCR extend operation performed for each
+measurement entry with the digest of the measurement entry as an input.
+
+::
+
+ IMA measurement list (with DIGLIM)
+
+ dlist
+ +--------------+
+ | header |
+ +--------------+
+ | file1 digest |
+ | file2 digest |
+ | file3 digest |
+ +--------------+
+
+``dlist`` is a digest list containing the digest of ``file1``, ``file2``
+and ``file3``. In the intended scenario, it is generated by a software
+vendor at the end of the building process, and retrieved by the
+administrator of the system where the digest list is loaded.
+
+::
+
+ entry# 1st boot 2nd boot 3rd boot
+ +----+---------------+ +----+---------------+ +----+---------------+
+ 0: | 11 | dlist measur. | | 11 | dlist measur. | | 11 | dlist measur. |
+ +----+---------------+ +----+---------------+ +----+---------------+
+ 1: < file1 measur. skip > < file3 measur. skip > < file2 measur. skip >
+
+ 2: < file2 measur. skip > < file2 measur. skip > < file3 measur. skip >
+ +----+---------------+
+ 3: < file3 measur. skip > < file1 measur. skip > | 11 | file4 measur. |
+ +----+---------------+
+
+ PCR: Extend = Extend != Extend
+ dlist dlist dlist, file4
+
+
+The first entry in the measurement list contains the digest of the digest
+list uploaded to the kernel at kernel initialization time.
+
+When a file is accessed, IMA queries DIGLIM with the calculated file digest
+and, if it is found, IMA skips the measurement.
+
+Thus, the only information sent to remote verifiers are: the list of
+files that could possibly be accessed (from the digest list), but not if
+they were accessed and when; the measurement of unknown files.
+
+Despite providing less information, this solution has the advantage that
+the good system state (i.e. when only ``file1``, ``file2`` and ``file3``
+are accessed) now can be represented with a deterministic PCR value (the
+PCR is extended only with the measurement of the digest list). Also, the
+bad system state can still be distinguished from the good state (the PCR is
+extended also with the measurement of ``file4``).
+
+If a TPM key is bound to the good PCR value, the TPM would allow the key to
+be used if ``file1``, ``file2`` or ``file3`` are accessed, regardless of
+the sequence in which they are accessed (the PCR value does not change),
+and would revoke the permission when the unknown ``file4`` is accessed (the
+PCR value changes). If a system is able to establish a TLS connection with
+a peer, this implicitly means that the system was in a good state (i.e.
+``file4`` was not accessed, otherwise the TPM would have denied the usage
+of the TPM key due to the key policy).
+
+
+Benefits for IMA Appraisal
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Extending secure boot to applications means being able to verify the
+provenance of files accessed. IMA does it by verifying file signatures with
+a key that it trusts, which requires Linux distribution vendors to
+additionally include in the package header a signature for each file that
+must be verified (there is the dedicated ``RPMTAG_FILESIGNATURES`` section
+in the RPM header).
+
+The proposed approach would be instead to verify data provenance from
+already available metadata (file digests) in existing packages. IMA would
+verify the signature of package metadata and search file digests extracted
+from package metadata and added to the hash table in the kernel.
+
+For RPMs, file digests can be found in the ``RPMTAG_FILEDIGESTS`` section
+of ``RPMTAG_IMMUTABLE``, whose signature is in ``RPMTAG_RSAHEADER``. For
+DEBs, file digests (unsafe to use due to a weak digest algorithm) can be
+found in the ``md5sum`` file, which can be indirectly verified from
+``Release.gpg``.
+
+The following figure highlights the differences between the current and the
+proposed approach.
+
+::
+
+ IMA appraisal (current solution, with file signatures):
+
+ appraise
+ +-----------+
+ V |
+ +-------------------------+-----+ +-------+-----+ |
+ | RPM header | | ima rpm | file1 | sig | |
+ | ... | | plugin +-------+-----+ +-----+
+ | file1 sig [to be added] | sig |--------> ... | IMA |
+ | ... | | +-------+-----+ +-----+
+ | fileN sig [to be added] | | | fileN | sig |
+ +-------------------------+-----+ +-------+-----+
+
+In this case, file signatures must be added to the RPM header, so that the
+``ima`` rpm plugin can extract them together with the file content. The RPM
+header signature is not used.
+
+::
+
+ IMA appraisal (with DIGLIM):
+
+ kernel hash table
+ with RPM header content
+ +---+ +--------------+
+ | |--->| file1 digest |
+ +---+ +--------------+
+ ...
+ +---+ appraise (file1)
+ | | <--------------+
+ +----------------+-----+ +---+ |
+ | RPM header | | ^ |
+ | ... | | digest_list | |
+ | file1 digest | sig | rpm plugin | +-------+ +-----+
+ | ... | |-------------+--->| file1 | | IMA |
+ | fileN digest | | +-------+ +-----+
+ +----------------+-----+ |
+ ^ |
+ +------------------------------------+
+ appraise (RPM header)
+
+In this case, the RPM header is used as it is, and its signature is used
+for IMA appraisal. Then, the ``digest_list`` rpm plugin executes the user
+space parser to parse the RPM header and add the extracted digests to an
+hash table in the kernel. IMA appraisal of the files in the RPM package
+consists in searching their digest in the hash table.
+
+Other than reusing available information as digest list, another advantage
+is the lower computational overhead compared to the solution with file
+signatures (only one signature verification for many files and digest
+lookup, instead of per file signature verification, see `Preliminary
+Performance Evaluation`_ for more details).
+
+
+Lifecycle
+---------
+
+The lifecycle of DIGLIM is represented in the following figure:
+
+::
+
+ Vendor premises (release process with modifications):
+
+ +------------+ +-----------------------+ +------------------------+
+ | 1. build a | | 2. generate and sign | | 3. publish the package |
+ | package |-->| a digest list from |-->| and digest list in |
+ | | | packaged files | | a repository |
+ +------------+ +-----------------------+ +------------------------+
+ |
+ |
+ User premises: |
+ V
+ +---------------------+ +------------------------+ +-----------------+
+ | 6. use digest lists | | 5. download the digest | | 4. download and |
+ | for measurement |<--| list and upload to |<--| install the |
+ | and/or appraisal | | the kernel | | package |
+ +---------------------+ +------------------------+ +-----------------+
+
+The figure above represents all the steps when a digest list is
+generated separately. However, as mentioned in `Contribution`_, in most
+cases existing packages can be already used as a source for digest lists,
+limiting the effort for software vendors.
+
+If, for example, RPMs are used as a source for digest lists, the figure
+above becomes:
+
+::
+
+ Vendor premises (release process without modifications):
+
+ +------------+ +------------------------+
+ | 1. build a | | 2. publish the package |
+ | package |-->| in a repository |---------------------+
+ | | | | |
+ +------------+ +------------------------+ |
+ |
+ |
+ User premises: |
+ V
+ +---------------------+ +------------------------+ +-----------------+
+ | 5. use digest lists | | 4. extract digest list | | 3. download and |
+ | for measurement |<--| from the package |<--| install the |
+ | and/or appraisal | | and upload to the | | package |
+ | | | kernel | | |
+ +---------------------+ +------------------------+ +-----------------+
+
+Step 4 can be performed with the ``digest_list`` rpm plugin and the user
+space parser, without changes to rpm itself.
+
+
+Security Assumptions
+--------------------
+
+As mentioned in the `Introduction`_, DIGLIM will be primarily used in
+conjunction with IMA to enforce a mandatory policy on all user space
+processes, including those owned by root. Even root, in a system with a
+locked-down kernel, cannot affect the enforcement of the mandatory policy
+or, if changes are permitted, it cannot do so without being detected.
+
+Given that the target of the enforcement are user space processes, DIGLIM
+cannot be placed in the target, as a Mandatory Access Control (MAC) design
+is required to have the components responsible to enforce the mandatory
+policy separated from the target.
+
+While locking-down a system and limiting actions with a mandatory policy is
+generally perceived by users as an obstacle, it has noteworthy benefits for
+the users themselves.
+
+First, it would timely block attempts by malicious software to steal or
+misuse user assets. Although users could query the package managers to
+detect them, detection would happen after the fact, or it wouldn't happen
+at all if the malicious software tampered with package managers. With a
+mandatory policy enforced by the kernel, users would still be able to
+decide which software they want to be executed except that, unlike package
+managers, the kernel is not affected by user space processes or root.
+
+Second, it might make systems more easily verifiable from outside, due to
+the limited actions the system allows. When users connect to a server, not
+only they would be able to verify the server identity, which is already
+possible with communication protocols like TLS, but also if the software
+running on that server can be trusted to handle their sensitive data.
+
+
+Adoption
+--------
+
+A former version of DIGLIM is used in the following OSes:
+
+- openEuler 20.09
+ https://github.com/openeuler-mirror/kernel/tree/openEuler-20.09
+
+- openEuler 21.03
+ https://github.com/openeuler-mirror/kernel/tree/openEuler-21.03
+
+Originally, DIGLIM was part of IMA (known as IMA Digest Lists). In this
+version, it has been redesigned as a standalone module with an API that
+makes its functionality accessible by IMA and, eventually, other
+subsystems.
+
+User Space Support
+------------------
+
+Digest lists can be generated and managed with ``digest-list-tools``:
+
+https://github.com/openeuler-mirror/digest-list-tools
+
+It includes two main applications:
+
+- ``gen_digest_lists``: generates digest lists from files in the
+ filesystem or from the RPM database (more digest list sources can be
+ supported);
+- ``manage_digest_lists``: converts and uploads digest lists to the
+ kernel.
+
+Integration with rpm is done with the ``digest_list`` plugin:
+
+https://gitee.com/src-openeuler/rpm/blob/master/Add-digest-list-plugin.patch
+
+This plugin writes the RPM header and its signature to a file, so that the
+file is ready to be appraised by IMA, and calls the user space parser to
+convert and upload the digest list to the kernel.
+
+
+Simple Usage Example (Tested with Fedora 33)
+--------------------------------------------
+
+1. Digest list generation (RPM headers and their signature are copied to
+ the specified directory):
+
+.. code-block:: bash
+
+ # mkdir /etc/digest_lists
+ # gen_digest_lists -t file -f rpm+db -d /etc/digest_lists -o add
+
+2. Digest list upload with the user space parser:
+
+.. code-block:: bash
+
+ # manage_digest_lists -p add-digest -d /etc/digest_lists
+
+3. First digest list query:
+
+.. code-block:: bash
+
+ # echo sha256-$(sha256sum /bin/cat) > /sys/kernel/security/integrity/diglim/digest_query
+ # cat /sys/kernel/security/integrity/diglim/digest_query
+ sha256-[...]-0-file_list-rpm-coreutils-8.32-18.fc33.x86_64 (actions: 0): version: 1, algo: sha256, type: 2, modifiers: 1, count: 106, datalen: 3392
+
+4. Second digest list query:
+
+.. code-block:: bash
+
+ # echo sha256-$(sha256sum /bin/zip) > /sys/kernel/security/integrity/diglim/digest_query
+ # cat /sys/kernel/security/integrity/diglim/digest_query
+ sha256-[...]-0-file_list-rpm-zip-3.0-27.fc33.x86_64 (actions: 0): version: 1, algo: sha256, type: 2, modifiers: 1, count: 4, datalen: 128
+
+
+Preliminary Performance Evaluation
+----------------------------------
+
+This section provides an initial estimation of the overhead introduced by
+DIGLIM. The estimation has been performed on a Fedora 33 virtual machine
+with 1447 packages installed. The virtual machine has 16 vCPU (host CPU:
+AMD Ryzen Threadripper PRO 3955WX 16-Cores) and 2G of RAM (host memory:
+64G). The virtual machine also has a vTPM with libtpms and swtpm as
+backend.
+
+After writing the RPM headers to files, the size of the directory
+containing them is 36M.
+
+After converting the RPM headers to the compact digest list, the size of
+the data being uploaded to the kernel is 3.6M.
+
+The time to load the entire RPM database is 0.628s.
+
+After loading the digest lists to the kernel, the slab usage due to
+indexing is (obtained with slab_nomerge in the kernel command line):
+
+::
+
+ OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
+ 118144 118144 100% 0,03K 923 128 3692K digest_list_item_ref_cache
+ 102400 102400 100% 0,03K 800 128 3200K digest_item_cache
+ 2646 2646 100% 0,09K 63 42 252K digest_list_item_cache
+
+The stats, obtained from the ``digests_count`` interface, introduced later,
+are:
+
+::
+
+ Parser digests: 0
+ File digests: 99100
+ Metadata digests: 0
+ Digest list digests: 1423
+
+On this installation, this would be the worst case in which all files are
+measured and/or appraised, which is currently not recommended without
+enforcing an integrity policy protecting mutable files. Infoflow LSM is a
+component to accomplish this task:
+
+https://patchwork.kernel.org/project/linux-integrity/cover/20190818235745.1417-1-roberto.sassu@huawei.com/
+
+The first manageable goal of IMA with DIGLIM is to use an execution policy,
+with measurement and/or appraisal of files executed or mapped in memory as
+executable (in addition to kernel modules and firmware). In this
+case, the digest list contains the digest only for those files. The numbers
+above change as follows.
+
+After converting the RPM headers to the compact digest list, the size of
+the data being uploaded to the kernel is 208K.
+
+The time to load the digest of binaries and shared libraries is 0.062s.
+
+After loading the digest lists to the kernel, the slab usage due to
+indexing is:
+
+::
+
+ OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
+ 7168 7168 100% 0,03K 56 128 224K digest_list_item_ref_cache
+ 7168 7168 100% 0,03K 56 128 224K digest_item_cache
+ 1134 1134 100% 0,09K 27 42 108K digest_list_item_cache
+
+
+The stats, obtained from the ``digests_count`` interface, are:
+
+::
+
+ Parser digests: 0
+ File digests: 5986
+ Metadata digests: 0
+ Digest list digests: 1104
+
+
+Comparison with IMA
+~~~~~~~~~~~~~~~~~~~
+
+This section compares the performance between the current solution for IMA
+measurement and appraisal, and IMA with DIGLIM.
+
+
+Workload A (without DIGLIM):
+
+#. cat file[0-5985] > /dev/null
+
+
+Workload B (with DIGLIM):
+
+#. echo $PWD/0-file_list-compact-file[0-1103] > <securityfs>/integrity/diglim/digest_list_add
+#. cat file[0-5985] > /dev/null
+
+
+Workload A execution time without IMA policy:
+
+::
+
+ real 0m0,155s
+ user 0m0,008s
+ sys 0m0,066s
+
+
+Measurement
+...........
+
+IMA policy:
+
+::
+
+ measure fowner=2000 func=FILE_CHECK mask=MAY_READ use_diglim=allow pcr=11 ima_template=ima-sig
+
+``use_diglim`` is a policy keyword not yet supported by IMA.
+
+
+Workload A execution time with IMA and 5986 files with signature measured:
+
+::
+
+ real 0m8,273s
+ user 0m0,008s
+ sys 0m2,537s
+
+
+Workload B execution time with IMA, 1104 digest lists with signature
+measured and uploaded to the kernel, and 5986 files with signature accessed
+but not measured (due to the file digest being found in the hash table):
+
+::
+
+ real 0m1,837s
+ user 0m0,036s
+ sys 0m0,583s
+
+
+Appraisal
+.........
+
+IMA policy:
+
+::
+
+ appraise fowner=2000 func=FILE_CHECK mask=MAY_READ use_diglim=allow
+
+``use_diglim`` is a policy keyword not yet supported by IMA.
+
+
+Workload A execution time with IMA and 5986 files with file signature
+appraised:
+
+::
+
+ real 0m2,197s
+ user 0m0,011s
+ sys 0m2,022s
+
+
+Workload B execution time with IMA, 1104 digest lists with signature
+appraised and uploaded to the kernel, and with 5986 files with signature
+not verified (due to the file digest being found in the hash table):
+
+::
+
+ real 0m0,982s
+ user 0m0,020s
+ sys 0m0,865s
diff --git a/Documentation/security/index.rst b/Documentation/security/index.rst
index 16335de04e8c..6c3aea41c55b 100644
--- a/Documentation/security/index.rst
+++ b/Documentation/security/index.rst
@@ -17,3 +17,4 @@ Security Documentation
tpm/index
digsig
landlock
+ diglim/index
diff --git a/MAINTAINERS b/MAINTAINERS
index 6c8be735cc91..c914dadd7e65 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5452,6 +5452,15 @@ L: linux-gpio@vger.kernel.org
S: Maintained
F: drivers/gpio/gpio-gpio-mm.c
+DIGLIM
+M: Roberto Sassu <roberto.sassu@huawei.com>
+L: linux-integrity@vger.kernel.org
+S: Supported
+T: git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git
+F: Documentation/security/diglim/architecture.rst
+F: Documentation/security/diglim/index.rst
+F: Documentation/security/diglim/introduction.rst
+
DIOLAN U2C-12 I2C DRIVER
M: Guenter Roeck <linux@roeck-us.net>
L: linux-i2c@vger.kernel.org
--
2.25.1
^ permalink raw reply related
* [RFC][PATCH v2 00/12] integrity: Introduce DIGLIM
From: Roberto Sassu @ 2021-07-26 16:36 UTC (permalink / raw)
To: zohar, gregkh, mchehab+huawei
Cc: linux-integrity, linux-security-module, linux-doc,
linux-kselftest, linux-kernel, Roberto Sassu
This patch set depends on:
- https://lore.kernel.org/linux-integrity/20210723085304.1760138-1-roberto.sassu@huawei.com/
- https://lore.kernel.org/linux-integrity/20210705115650.3373599-1-roberto.sassu@huawei.com/
I still kept pointer math to optimize the size of the digest_list_item_ref
structure. Replacing offsets with pointers would cause the size of the
structure to double. I could do this in the next version of the patch set
if the size change is acceptable.
Digest Lists Integrity Module (DIGLIM) is a new component added to the
integrity subsystem in the kernel, primarily aiming to aid Integrity
Measurement Architecture (IMA) in the process of checking the integrity
of file content and metadata. It accomplishes this task by storing
reference values coming from software vendors and by reporting whether
or not the digest of file content or metadata calculated by IMA (or EVM)
is found among those values. In this way, IMA can decide, depending on
the result of a query, if a measurement should be taken or access to the
file should be granted. The Security Assumptions section explains more
in detail why this component has been placed in the kernel.
The main benefits of using IMA in conjunction with DIGLIM are the
ability to implement advanced remote attestation schemes based on the
usage of a TPM key for establishing a TLS secure channel [1][2], and to
reduce the burden on Linux distribution vendors to extend secure boot at
OS level to applications.
DIGLIM does not have the complexity of feature-rich databases. In fact,
its main functionality comes from the hash table primitives already in
the kernel. It does not have an ad-hoc storage module, it just indexes
data in a fixed format (digest lists, a set of concatenated digests
preceded by a header), copied to kernel memory as they are. Lastly, it
does not support database-oriented languages such as SQL, but only
accepts a digest and its algorithm as a query.
The only digest list format supported by DIGLIM is called compact.
However, Linux distribution vendors don't have to generate new digest
lists in this format for the packages they release, as already available
information, such as RPM headers and DEB package metadata, can be
already used as a source for reference values (they already include file
digests), with a user space parser taking care of the conversion to the
compact format.
Although one might perceive that storing file or metadata digests for a
Linux distribution would significantly increase the memory usage, this
does not seem to be the case. As an anticipation of the evaluation done
in the Preliminary Performance Evaluation section, protecting binaries
and shared libraries of a minimal Fedora 33 installation requires 208K
of memory for the digest lists plus 556K for indexing.
In exchange for a slightly increased memory usage, DIGLIM improves the
performance of the integrity subsystem. In the considered scenario, IMA
measurement and appraisal with digest lists requires respectively less
than one quarter and less than half the time, compared to the current
solution.
DIGLIM also keeps track of whether digest lists have been processed in
some way (e.g. measured or appraised by IMA). This is important for
example for remote attestation, so that remote verifiers understand what
has been uploaded to the kernel.
DIGLIM behaves like a transactional database, i.e. it has the ability to
roll back to the beginning of the transaction if an error occurred
during the addition of a digest list (the deletion operation always
succeeds). This capability has been tested with an ad-hoc fault
injection mechanism capable of simulating failures during the
operations.
Finally, DIGLIM exposes to user space, through securityfs, the digest
lists currently loaded, the number of digests added, a query interface
and an interface to set digest list labels.
[1] LSS EU 2019
- slides:
https://static.sched.com/hosted_files/lsseu2019/bd/secure_attested_communication_channels_lss_eu_2019.pdf
- video: https://youtu.be/mffdQgkvDNY
[2] FutureTPM EU project, final review meeting demo
- slides:
https://futuretpm.eu/images/07-3-FutureTPM-Final-Review-Slides-WP6-Device-Management-Use-Case-HWDU.pdf
- video: https://vimeo.com/528251864/4c1d55abcd
Binary Integrity
Integrity is a fundamental security property in information systems.
Integrity could be described as the condition in which a generic
component is just after it has been released by the entity that created
it.
One way to check whether a component is in this condition (called binary
integrity) is to calculate its digest and to compare it with a reference
value (i.e. the digest calculated in controlled conditions, when the
component is released).
IMA, a software part of the integrity subsystem, can perform such
evaluation and execute different actions:
- store the digest in an integrity-protected measurement list, so that
it can be sent to a remote verifier for analysis;
- compare the calculated digest with a reference value (usually
protected with a signature) and deny operations if the file is found
corrupted;
- store the digest in the system log.
Contribution
DIGLIM further enhances the capabilities offered by IMA-based solutions
and, at the same time, makes them more practical to adopt by reusing
existing sources as reference values for integrity decisions.
Possible sources for digest lists are:
- RPM headers;
- Debian repository metadata.
Benefits for IMA Measurement
One of the issues that arises when files are measured by the OS is that,
due to parallel execution, the order in which file accesses happen
cannot be predicted. Since the TPM Platform Configuration Register (PCR)
extend operation, executed after each file measurement,
cryptographically binds the current measurement to the previous ones,
the PCR value at the end of a workload cannot be predicted too.
Thus, even if the usage of a TPM key, bound to a PCR value, should be
allowed when only good files were accessed, the TPM could unexpectedly
deny an operation on that key if files accesses did not happen as stated
by the key policy (which allows only one of the possible sequences).
DIGLIM solves this issue by making the PCR value stable over the time
and not dependent on file accesses. The following figure depicts the
current and the new approaches:
IMA measurement list (current)
entry# 1st boot 2nd boot 3rd boot
+----+---------------+ +----+---------------+ +----+---------------+
1: | 10 | file1 measur. | | 10 | file3 measur. | | 10 | file2 measur. |
+----+---------------+ +----+---------------+ +----+---------------+
2: | 10 | file2 measur. | | 10 | file2 measur. | | 10 | file3 measur. |
+----+---------------+ +----+---------------+ +----+---------------+
3: | 10 | file3 measur. | | 10 | file1 measur. | | 10 | file4 measur. |
+----+---------------+ +----+---------------+ +----+---------------+
PCR: Extend != Extend != Extend
file1, file2, file3 file3, file2, file1 file2, file3, file4
PCR Extend definition:
PCR(new value) = Hash(Hash(meas. entry), PCR(previous value))
A new entry in the measurement list is created by IMA for each file
access. Assuming that file1, file2 and file3 are files provided by the
software vendor, file4 is an unknown file, the first two PCR values
above represent a good system state, the third a bad system state. The
PCR values are the result of the PCR extend operation performed for each
measurement entry with the digest of the measurement entry as an input.
IMA measurement list (with DIGLIM)
dlist
+--------------+
| header |
+--------------+
| file1 digest |
| file2 digest |
| file3 digest |
+--------------+
dlist is a digest list containing the digest of file1, file2 and file3.
In the intended scenario, it is generated by a software vendor at the
end of the building process, and retrieved by the administrator of the
system where the digest list is loaded.
entry# 1st boot 2nd boot 3rd boot
+----+---------------+ +----+---------------+ +----+---------------+
0: | 11 | dlist measur. | | 11 | dlist measur. | | 11 | dlist measur. |
+----+---------------+ +----+---------------+ +----+---------------+
1: < file1 measur. skip > < file3 measur. skip > < file2 measur. skip >
2: < file2 measur. skip > < file2 measur. skip > < file3 measur. skip >
+----+---------------+
3: < file3 measur. skip > < file1 measur. skip > | 11 | file4 measur. |
+----+---------------+
PCR: Extend = Extend != Extend
dlist dlist dlist, file4
The first entry in the measurement list contains the digest of the
digest list uploaded to the kernel at kernel initialization time.
When a file is accessed, IMA queries DIGLIM with the calculated file
digest and, if it is found, IMA skips the measurement.
Thus, the only information sent to remote verifiers are: the list of
files that could possibly be accessed (from the digest list), but not if
they were accessed and when; the measurement of unknown files.
Despite providing less information, this solution has the advantage that
the good system state (i.e. when only file1, file2 and file3 are
accessed) now can be represented with a deterministic PCR value (the PCR
is extended only with the measurement of the digest list). Also, the bad
system state can still be distinguished from the good state (the PCR is
extended also with the measurement of file4).
If a TPM key is bound to the good PCR value, the TPM would allow the key
to be used if file1, file2 or file3 are accessed, regardless of the
sequence in which they are accessed (the PCR value does not change), and
would revoke the permission when the unknown file4 is accessed (the PCR
value changes). If a system is able to establish a TLS connection with a
peer, this implicitly means that the system was in a good state (i.e.
file4 was not accessed, otherwise the TPM would have denied the usage of
the TPM key due to the key policy).
Benefits for IMA Appraisal
Extending secure boot to applications means being able to verify the
provenance of files accessed. IMA does it by verifying file signatures
with a key that it trusts, which requires Linux distribution vendors to
additionally include in the package header a signature for each file
that must be verified (there is the dedicated RPMTAG_FILESIGNATURES
section in the RPM header).
The proposed approach would be instead to verify data provenance from
already available metadata (file digests) in existing packages. IMA
would verify the signature of package metadata and search file digests
extracted from package metadata and added to the hash table in the
kernel.
For RPMs, file digests can be found in the RPMTAG_FILEDIGESTS section of
RPMTAG_IMMUTABLE, whose signature is in RPMTAG_RSAHEADER. For DEBs, file
digests (unsafe to use due to a weak digest algorithm) can be found in
the md5sum file, which can be indirectly verified from Release.gpg.
The following figure highlights the differences between the current and
the proposed approach.
IMA appraisal (current solution, with file signatures):
appraise
+-----------+
V |
+-------------------------+-----+ +-------+-----+ |
| RPM header | | ima rpm | file1 | sig | |
| ... | | plugin +-------+-----+ +-----+
| file1 sig [to be added] | sig |--------> ... | IMA |
| ... | | +-------+-----+ +-----+
| fileN sig [to be added] | | | fileN | sig |
+-------------------------+-----+ +-------+-----+
In this case, file signatures must be added to the RPM header, so that
the ima rpm plugin can extract them together with the file content. The
RPM header signature is not used.
IMA appraisal (with DIGLIM):
kernel hash table
with RPM header content
+---+ +--------------+
| |--->| file1 digest |
+---+ +--------------+
...
+---+ appraise (file1)
| | <--------------+
+----------------+-----+ +---+ |
| RPM header | | ^ |
| ... | | digest_list | |
| file1 digest | sig | rpm plugin | +-------+ +-----+
| ... | |-------------+--->| file1 | | IMA |
| fileN digest | | +-------+ +-----+
+----------------+-----+ |
^ |
+------------------------------------+
appraise (RPM header)
In this case, the RPM header is used as it is, and its signature is used
for IMA appraisal. Then, the digest_list rpm plugin executes the user
space parser to parse the RPM header and add the extracted digests to an
hash table in the kernel. IMA appraisal of the files in the RPM package
consists in searching their digest in the hash table.
Other than reusing available information as digest list, another
advantage is the lower computational overhead compared to the solution
with file signatures (only one signature verification for many files and
digest lookup, instead of per file signature verification, see
Preliminary Performance Evaluation for more details).
Lifecycle
The lifecycle of DIGLIM is represented in the following figure:
Vendor premises (release process with modifications):
+------------+ +-----------------------+ +------------------------+
| 1. build a | | 2. generate and sign | | 3. publish the package |
| package |-->| a digest list from |-->| and digest list in |
| | | packaged files | | a repository |
+------------+ +-----------------------+ +------------------------+
|
|
User premises: |
V
+---------------------+ +------------------------+ +-----------------+
| 6. use digest lists | | 5. download the digest | | 4. download and |
| for measurement |<--| list and upload to |<--| install the |
| and/or appraisal | | the kernel | | package |
+---------------------+ +------------------------+ +-----------------+
The figure above represents all the steps when a digest list is
generated separately. However, as mentioned in Contribution, in most
cases existing packages can be already used as a source for digest
lists, limiting the effort for software vendors.
If, for example, RPMs are used as a source for digest lists, the figure
above becomes:
Vendor premises (release process without modifications):
+------------+ +------------------------+
| 1. build a | | 2. publish the package |
| package |-->| in a repository |---------------------+
| | | | |
+------------+ +------------------------+ |
|
|
User premises: |
V
+---------------------+ +------------------------+ +-----------------+
| 5. use digest lists | | 4. extract digest list | | 3. download and |
| for measurement |<--| from the package |<--| install the |
| and/or appraisal | | and upload to the | | package |
| | | kernel | | |
+---------------------+ +------------------------+ +-----------------+
Step 4 can be performed with the digest_list rpm plugin and the user
space parser, without changes to rpm itself.
Security Assumptions
As mentioned in the Introduction, DIGLIM will be primarily used in
conjunction with IMA to enforce a mandatory policy on all user space
processes, including those owned by root. Even root, in a system with a
locked-down kernel, cannot affect the enforcement of the mandatory
policy or, if changes are permitted, it cannot do so without being
detected.
Given that the target of the enforcement are user space processes,
DIGLIM cannot be placed in the target, as a Mandatory Access Control
(MAC) design is required to have the components responsible to enforce
the mandatory policy separated from the target.
While locking-down a system and limiting actions with a mandatory policy
is generally perceived by users as an obstacle, it has noteworthy
benefits for the users themselves.
First, it would timely block attempts by malicious software to steal or
misuse user assets. Although users could query the package managers to
detect them, detection would happen after the fact, or it wouldn't
happen at all if the malicious software tampered with package managers.
With a mandatory policy enforced by the kernel, users would still be
able to decide which software they want to be executed except that,
unlike package managers, the kernel is not affected by user space
processes or root.
Second, it might make systems more easily verifiable from outside, due
to the limited actions the system allows. When users connect to a
server, not only they would be able to verify the server identity, which
is already possible with communication protocols like TLS, but also if
the software running on that server can be trusted to handle their
sensitive data.
Adoption
A former version of DIGLIM is used in the following OSes:
- openEuler 20.09
https://github.com/openeuler-mirror/kernel/tree/openEuler-20.09
- openEuler 21.03
https://github.com/openeuler-mirror/kernel/tree/openEuler-21.03
Originally, DIGLIM was part of IMA (known as IMA Digest Lists). In this
version, it has been redesigned as a standalone module with an API that
makes its functionality accessible by IMA and, eventually, other
subsystems.
User Space Support
Digest lists can be generated and managed with digest-list-tools:
https://github.com/openeuler-mirror/digest-list-tools
It includes two main applications:
- gen_digest_lists: generates digest lists from files in the
filesystem or from the RPM database (more digest list sources can be
supported);
- manage_digest_lists: converts and uploads digest lists to the
kernel.
Integration with rpm is done with the digest_list plugin:
https://gitee.com/src-openeuler/rpm/blob/master/Add-digest-list-plugin.patch
This plugin writes the RPM header and its signature to a file, so that
the file is ready to be appraised by IMA, and calls the user space
parser to convert and upload the digest list to the kernel.
Simple Usage Example (Tested with Fedora 33)
1. Digest list generation (RPM headers and their signature are copied
to the specified directory):
# mkdir /etc/digest_lists
# gen_digest_lists -t file -f rpm+db -d /etc/digest_lists -o add
2. Digest list upload with the user space parser:
# manage_digest_lists -p add-digest -d /etc/digest_lists
3. First digest list query:
# echo sha256-$(sha256sum /bin/cat) > /sys/kernel/security/integrity/diglim/digest_query
# cat /sys/kernel/security/integrity/diglim/digest_query
sha256-[...]-0-file_list-rpm-coreutils-8.32-18.fc33.x86_64 (actions: 0): version: 1, algo: sha256, type: 2, modifiers: 1, count: 106, datalen: 3392
4. Second digest list query:
# echo sha256-$(sha256sum /bin/zip) > /sys/kernel/security/integrity/diglim/digest_query
# cat /sys/kernel/security/integrity/diglim/digest_query
sha256-[...]-0-file_list-rpm-zip-3.0-27.fc33.x86_64 (actions: 0): version: 1, algo: sha256, type: 2, modifiers: 1, count: 4, datalen: 128
Preliminary Performance Evaluation
This section provides an initial estimation of the overhead introduced
by DIGLIM. The estimation has been performed on a Fedora 33 virtual
machine with 1447 packages installed. The virtual machine has 16 vCPU
(host CPU: AMD Ryzen Threadripper PRO 3955WX 16-Cores) and 2G of RAM
(host memory: 64G). The virtual machine also has a vTPM with libtpms and
swtpm as backend.
After writing the RPM headers to files, the size of the directory
containing them is 36M.
After converting the RPM headers to the compact digest list, the size of
the data being uploaded to the kernel is 3.6M.
The time to load the entire RPM database is 0.628s.
After loading the digest lists to the kernel, the slab usage due to
indexing is (obtained with slab_nomerge in the kernel command line):
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
118144 118144 100% 0,03K 923 128 3692K digest_list_item_ref_cache
102400 102400 100% 0,03K 800 128 3200K digest_item_cache
2646 2646 100% 0,09K 63 42 252K digest_list_item_cache
The stats, obtained from the digests_count interface, introduced later,
are:
Parser digests: 0
File digests: 99100
Metadata digests: 0
Digest list digests: 1423
On this installation, this would be the worst case in which all files
are measured and/or appraised, which is currently not recommended
without enforcing an integrity policy protecting mutable files. Infoflow
LSM is a component to accomplish this task:
https://patchwork.kernel.org/project/linux-integrity/cover/20190818235745.1417-1-roberto.sassu@huawei.com/
The first manageable goal of IMA with DIGLIM is to use an execution
policy, with measurement and/or appraisal of files executed or mapped in
memory as executable (in addition to kernel modules and firmware). In
this case, the digest list contains the digest only for those files. The
numbers above change as follows.
After converting the RPM headers to the compact digest list, the size of
the data being uploaded to the kernel is 208K.
The time to load the digest of binaries and shared libraries is 0.062s.
After loading the digest lists to the kernel, the slab usage due to
indexing is:
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
7168 7168 100% 0,03K 56 128 224K digest_list_item_ref_cache
7168 7168 100% 0,03K 56 128 224K digest_item_cache
1134 1134 100% 0,09K 27 42 108K digest_list_item_cache
The stats, obtained from the digests_count interface, are:
Parser digests: 0
File digests: 5986
Metadata digests: 0
Digest list digests: 1104
Comparison with IMA
This section compares the performance between the current solution for
IMA measurement and appraisal, and IMA with DIGLIM.
Workload A (without DIGLIM):
1. cat file[0-5985] > /dev/null
Workload B (with DIGLIM):
1. echo $PWD/0-file_list-compact-file[0-1103] >
<securityfs>/integrity/diglim/digest_list_add
2. cat file[0-5985] > /dev/null
Workload A execution time without IMA policy:
real 0m0,155s
user 0m0,008s
sys 0m0,066s
Measurement
IMA policy:
measure fowner=2000 func=FILE_CHECK mask=MAY_READ use_diglim=allow pcr=11 ima_template=ima-sig
use_diglim is a policy keyword not yet supported by IMA.
Workload A execution time with IMA and 5986 files with signature
measured:
real 0m8,273s
user 0m0,008s
sys 0m2,537s
Workload B execution time with IMA, 1104 digest lists with signature
measured and uploaded to the kernel, and 5986 files with signature
accessed but not measured (due to the file digest being found in the
hash table):
real 0m1,837s
user 0m0,036s
sys 0m0,583s
Appraisal
IMA policy:
appraise fowner=2000 func=FILE_CHECK mask=MAY_READ use_diglim=allow
use_diglim is a policy keyword not yet supported by IMA.
Workload A execution time with IMA and 5986 files with file signature
appraised:
real 0m2,197s
user 0m0,011s
sys 0m2,022s
Workload B execution time with IMA, 1104 digest lists with signature
appraised and uploaded to the kernel, and with 5986 files with signature
not verified (due to the file digest being found in the hash table):
real 0m0,982s
user 0m0,020s
sys 0m0,865s
Changelog
v1:
- remove 'ima: Add digest, algo, measured parameters to
ima_measure_critical_data()', replaced by:
https://lore.kernel.org/linux-integrity/20210705090922.3321178-1-roberto.sassu@huawei.com/
- add 'Lifecycle' subsection to better clarify how digest lists are
generated and used (suggested by Greg KH)
- remove 'Possible Usages' subsection and add 'Benefits for IMA
Measurement' and 'Benefits for IMA Appraisal' subsubsections
- add 'Preliminary Performance Evaluation' subsection
- declare digest_offset and hdr_offset in the digest_list_item_ref
structure as u32 (sufficient for digest lists of 4G) to make room for a
list_head structure (digest_list_item_ref size: 32)
- implement digest list reference management with a linked list instead of
an array
- reorder structure members for better alignment (suggested by Mauro)
- rename digest_lookup() to __digest_lookup() (suggested by Mauro)
- introduce an object cache for each defined structure
- replace atomic_long_t with unsigned long in h_table structure definition
(suggested by Greg KH)
- remove GPL2 license text and file names (suggested by Greg KH)
- ensure that the _reserved field of compact_list_hdr is equal to zero
(suggested by Greg KH)
- dynamically allocate the buffer in digest_lists_show_htable_len() to
avoid frame size warning (reported by kernel test robot, dynamic
allocation suggested by Mauro)
- split documentation in multiple files and reference the source code
(suggested by Mauro)
- use #ifdef in include/linux/diglim.h
- improve generation of event name for IMA measurements
- add new patch to introduce the 'Remote Attestation' section in the
documentation
- fix assignment of actions variable in digest_list_read() and
digest_list_write()
- always release dentry reference when digest_list_get_secfs_files() is
called
- rewrite add/del and query interfaces to take advantage of m->private
- prevent deletion of a digest list only if there are actions done at
addition time that are not currently being performed
- fix doc warnings (replace Returns with Return:)
- perform queries of digest list digests in the existing tests
- add new tests: digest_list_add_del_test_file_upload_measured,
digest_list_check_measurement_list_test_file_upload and
digest_list_check_measurement_list_test_buffer_upload
- don't return a value from digest_del(), digest_list_ref_del, and
digest_list_del()
- improve Makefile for tests
Roberto Sassu (12):
diglim: Overview
diglim: Basic definitions
diglim: Objects
diglim: Methods
diglim: Parser
diglim: Interfaces - digest_list_add, digest_list_del
diglim: Interfaces - digest_lists_loaded
diglim: Interfaces - digest_label
diglim: Interfaces - digest_query
diglim: Interfaces - digests_count
diglim: Remote Attestation
diglim: Tests
.../security/diglim/architecture.rst | 45 +
.../security/diglim/implementation.rst | 255 +++
Documentation/security/diglim/index.rst | 14 +
.../security/diglim/introduction.rst | 631 ++++++++
.../security/diglim/remote_attestation.rst | 87 ++
Documentation/security/diglim/tests.rst | 66 +
Documentation/security/index.rst | 1 +
MAINTAINERS | 19 +
include/linux/diglim.h | 28 +
include/linux/kernel_read_file.h | 1 +
include/uapi/linux/diglim.h | 51 +
security/integrity/Kconfig | 1 +
security/integrity/Makefile | 1 +
security/integrity/diglim/Kconfig | 11 +
security/integrity/diglim/Makefile | 8 +
security/integrity/diglim/diglim.h | 157 ++
security/integrity/diglim/fs.c | 782 ++++++++++
security/integrity/diglim/methods.c | 499 ++++++
security/integrity/diglim/parser.c | 274 ++++
security/integrity/integrity.h | 4 +
tools/testing/selftests/Makefile | 1 +
tools/testing/selftests/diglim/Makefile | 19 +
tools/testing/selftests/diglim/common.c | 115 ++
tools/testing/selftests/diglim/common.h | 31 +
tools/testing/selftests/diglim/config | 3 +
tools/testing/selftests/diglim/selftest.c | 1382 +++++++++++++++++
26 files changed, 4486 insertions(+)
create mode 100644 Documentation/security/diglim/architecture.rst
create mode 100644 Documentation/security/diglim/implementation.rst
create mode 100644 Documentation/security/diglim/index.rst
create mode 100644 Documentation/security/diglim/introduction.rst
create mode 100644 Documentation/security/diglim/remote_attestation.rst
create mode 100644 Documentation/security/diglim/tests.rst
create mode 100644 include/linux/diglim.h
create mode 100644 include/uapi/linux/diglim.h
create mode 100644 security/integrity/diglim/Kconfig
create mode 100644 security/integrity/diglim/Makefile
create mode 100644 security/integrity/diglim/diglim.h
create mode 100644 security/integrity/diglim/fs.c
create mode 100644 security/integrity/diglim/methods.c
create mode 100644 security/integrity/diglim/parser.c
create mode 100644 tools/testing/selftests/diglim/Makefile
create mode 100644 tools/testing/selftests/diglim/common.c
create mode 100644 tools/testing/selftests/diglim/common.h
create mode 100644 tools/testing/selftests/diglim/config
create mode 100644 tools/testing/selftests/diglim/selftest.c
--
2.25.1
^ permalink raw reply
* Re: [PATCH RFC 0/9] sk_buff: optimize layout for GRO
From: Casey Schaufler @ 2021-07-26 15:13 UTC (permalink / raw)
To: Florian Westphal
Cc: Paul Moore, Paolo Abeni, netdev, David S. Miller, Jakub Kicinski,
Eric Dumazet, linux-security-module, selinux, Casey Schaufler
In-Reply-To: <20210725225200.GL9904@breakpoint.cc>
On 7/25/2021 3:52 PM, Florian Westphal wrote:
> Casey Schaufler <casey@schaufler-ca.com> wrote:
>> RedHat and android use SELinux and will want this. Ubuntu doesn't
>> yet, but netfilter in in the AppArmor task list. Tizen definitely
>> uses it with Smack. The notion that security modules are only used
>> in fringe cases is antiquated.
> I was not talking about LSM in general, I was referring to the
> extended info that Paul mentioned.
>
> If thats indeed going to be used on every distro then skb extensions
> are not suitable for this, it would result in extr akmalloc for every
> skb.
I am explicitly talking about the use of secmarks. All my
references are uses of secmarks.
>>> It certainly makes more sense to me than doing lookups
>>> in a hashtable based on a ID
>> Agreed. The data burden required to support a hash scheme
>> for the security module stacking case is staggering.
> It depends on the type of data (and its lifetime).
>
> I suspect you have something that is more like skb->dev/dst,
> i.e. reference to object that persists after the skb is free'd.
Just so. Only to make it more complicated, SELinux and Smack,
the two LSMs currently using secmarks, use them differently.
SELinux uses u32 "secids" natively, but Smack suffers serious
performance degradation because it has to look up (efficiently,
but look up nonetheless) the real Smack value on every packet.
Please, I know about hash caches, cache hashes and all sorts
of clever tricks to reduce the impact. Nothing beats having the
end value up front.
^ permalink raw reply
* [PATCH][V2] security: keys: trusted: Fix memory leaks on allocated blob
From: Colin King @ 2021-07-26 11:44 UTC (permalink / raw)
To: James Bottomley, Jarkko Sakkinen, Mimi Zohar, David Howells,
James Morris, Serge E . Hallyn, linux-integrity, keyrings,
linux-security-module
Cc: kernel-janitors, linux-kernel
From: Colin Ian King <colin.king@canonical.com>
There are several error return paths that don't kfree the allocated
blob, leading to memory leaks. Ensure blob is initialized to null as
some of the error return paths in function tpm2_key_decode do not
change blob. Add an error return path to kfree blob and use this on
the current leaky returns.
Addresses-Coverity: ("Resource leak")
Fixes: f2219745250f ("security: keys: trusted: use ASN.1 TPM2 key format for the blobs")
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
V2: Add a couple more leaky return path fixes as noted by Sumit Garg
Add the if (blob != payload->blob) check on the kfree as
noted by Dan Carpenter
---
security/keys/trusted-keys/trusted_tpm2.c | 39 ++++++++++++++++-------
1 file changed, 27 insertions(+), 12 deletions(-)
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 0165da386289..a2cfdfdf17fa 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -366,7 +366,7 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
unsigned int private_len;
unsigned int public_len;
unsigned int blob_len;
- u8 *blob, *pub;
+ u8 *blob = NULL, *pub;
int rc;
u32 attrs;
@@ -378,22 +378,30 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
}
/* new format carries keyhandle but old format doesn't */
- if (!options->keyhandle)
- return -EINVAL;
+ if (!options->keyhandle) {
+ rc = -EINVAL;
+ goto err;
+ }
/* must be big enough for at least the two be16 size counts */
- if (payload->blob_len < 4)
- return -EINVAL;
+ if (payload->blob_len < 4) {
+ rc = -EINVAL;
+ goto err;
+ }
private_len = get_unaligned_be16(blob);
/* must be big enough for following public_len */
- if (private_len + 2 + 2 > (payload->blob_len))
- return -E2BIG;
+ if (private_len + 2 + 2 > (payload->blob_len)) {
+ rc = -E2BIG;
+ goto err;
+ }
public_len = get_unaligned_be16(blob + 2 + private_len);
- if (private_len + 2 + public_len + 2 > payload->blob_len)
- return -E2BIG;
+ if (private_len + 2 + public_len + 2 > payload->blob_len) {
+ rc = -E2BIG;
+ goto err;
+ }
pub = blob + 2 + private_len + 2;
/* key attributes are always at offset 4 */
@@ -406,12 +414,14 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
payload->migratable = 1;
blob_len = private_len + public_len + 4;
- if (blob_len > payload->blob_len)
- return -E2BIG;
+ if (blob_len > payload->blob_len) {
+ rc = -E2BIG;
+ goto err;
+ }
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
if (rc)
- return rc;
+ goto err;
tpm_buf_append_u32(&buf, options->keyhandle);
tpm2_buf_append_auth(&buf, TPM2_RS_PW,
@@ -441,6 +451,11 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
rc = -EPERM;
return rc;
+
+err:
+ if (blob != payload->blob)
+ kfree(blob);
+ return rc;
}
/**
--
2.31.1
^ permalink raw reply related
page: next (older) | prev (newer) | latest
- recent:[subjects (threaded)|topics (new)|topics (active)]
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox