* [PATCH v4 04/11] security: keys: trusted: Include TPM2 creation data
2022-11-03 18:01 [PATCH v4 00/11] Encrypted Hibernation Evan Green
@ 2022-11-03 18:01 ` Evan Green
2022-11-04 18:33 ` Kees Cook
2022-11-03 18:01 ` [PATCH v4 05/11] security: keys: trusted: Allow storage of PCR values in " Evan Green
2022-11-03 18:01 ` [PATCH v4 06/11] security: keys: trusted: Verify " Evan Green
2 siblings, 1 reply; 9+ messages in thread
From: Evan Green @ 2022-11-03 18:01 UTC (permalink / raw)
To: linux-kernel
Cc: corbet, linux-pm, rjw, gwendal, apronin, Pavel Machek, Kees Cook,
Matthew Garrett, linux-integrity, jejb, zohar, dlunev,
Eric Biggers, Ben Boeckel, jarkko, Evan Green, David Howells,
James Morris, Paul Moore, Serge E. Hallyn, keyrings,
linux-security-module
In addition to the private key and public key, the TPM2_Create
command may also return creation data, a creation hash, and a creation
ticket. These fields allow the TPM to attest to the contents of a
specified set of PCRs at the time the trusted key was created. Encrypted
hibernation will use this to ensure that PCRs settable only by the
kernel were set properly at the time of creation, indicating this is an
authentic hibernate key.
Encode these additional parameters into the ASN.1 created to represent
the key blob. The new fields are made optional so that they don't bloat
key blobs which don't need them, and to ensure interoperability with
old blobs.
Signed-off-by: Evan Green <evgreen@chromium.org>
---
(no changes since v3)
Changes in v3:
- Fix SoB and -- note ordering (Kees)
- Add comments describing the TPM2 spec type names for the new fields
in tpm2key.asn1 (Kees)
- Add len buffer checks in tpm2_key_encode() (Kees)
This is a replacement for Matthew's original patch here:
https://patchwork.kernel.org/patch/12096489/
That patch was written before the exported key format was switched to
ASN.1. This patch accomplishes the same thing (saving, loading, and
getting pointers to the creation data) while utilizing the new ASN.1
format.
---
include/keys/trusted-type.h | 8 +
security/keys/trusted-keys/tpm2key.asn1 | 15 +-
security/keys/trusted-keys/trusted_tpm2.c | 216 +++++++++++++++++++---
3 files changed, 213 insertions(+), 26 deletions(-)
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index 4eb64548a74f1a..209086fed240a5 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -22,15 +22,23 @@
#define MAX_BLOB_SIZE 512
#define MAX_PCRINFO_SIZE 64
#define MAX_DIGEST_SIZE 64
+#define MAX_CREATION_DATA 412
+#define MAX_TK 76
struct trusted_key_payload {
struct rcu_head rcu;
unsigned int key_len;
unsigned int blob_len;
+ unsigned int creation_len;
+ unsigned int creation_hash_len;
+ unsigned int tk_len;
unsigned char migratable;
unsigned char old_format;
unsigned char key[MAX_KEY_SIZE + 1];
unsigned char blob[MAX_BLOB_SIZE];
+ unsigned char *creation;
+ unsigned char *creation_hash;
+ unsigned char *tk;
};
struct trusted_key_options {
diff --git a/security/keys/trusted-keys/tpm2key.asn1 b/security/keys/trusted-keys/tpm2key.asn1
index f57f869ad60068..608f8d9ca95fa8 100644
--- a/security/keys/trusted-keys/tpm2key.asn1
+++ b/security/keys/trusted-keys/tpm2key.asn1
@@ -7,5 +7,18 @@ TPMKey ::= SEQUENCE {
emptyAuth [0] EXPLICIT BOOLEAN OPTIONAL,
parent INTEGER ({tpm2_key_parent}),
pubkey OCTET STRING ({tpm2_key_pub}),
- privkey OCTET STRING ({tpm2_key_priv})
+ privkey OCTET STRING ({tpm2_key_priv}),
+ ---
+ --- A TPM2B_CREATION_DATA struct as returned from the TPM2_Create command.
+ ---
+ creationData [1] EXPLICIT OCTET STRING OPTIONAL ({tpm2_key_creation_data}),
+ ---
+ --- A TPM2B_DIGEST of the creationHash as returned from the TPM2_Create
+ --- command.
+ ---
+ creationHash [2] EXPLICIT OCTET STRING OPTIONAL ({tpm2_key_creation_hash}),
+ ---
+ --- A TPMT_TK_CREATION ticket as returned from the TPM2_Create command.
+ ---
+ creationTk [3] EXPLICIT OCTET STRING OPTIONAL ({tpm2_key_creation_tk})
}
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index 2b2c8eb258d5bd..e1388d7d799a36 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -33,19 +33,54 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
u8 *src, u32 len)
{
const int SCRATCH_SIZE = PAGE_SIZE;
+ u8 *end = src + len;
u8 *scratch = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
u8 *work = scratch, *work1;
u8 *end_work = scratch + SCRATCH_SIZE;
u8 *priv, *pub;
+ u8 *creation_data = NULL, *creation_hash = NULL, *creation_tk = NULL;
+ u16 creation_data_len, creation_hash_len = 0, creation_tk_len = 0;
u16 priv_len, pub_len;
+ int rc;
+
+ if (src + 2 > end)
+ return -EINVAL;
priv_len = get_unaligned_be16(src) + 2;
priv = src;
src += priv_len;
-
+ if (src + 2 > end)
+ return -EINVAL;
pub_len = get_unaligned_be16(src) + 2;
pub = src;
+ src += pub_len;
+ if (src + 2 > end)
+ return -EINVAL;
+ creation_data_len = get_unaligned_be16(src);
+ if (creation_data_len) {
+ creation_data_len += 2;
+ creation_data = src;
+ src += creation_data_len;
+ if (src + 2 > end)
+ return -EINVAL;
+
+ creation_hash_len = get_unaligned_be16(src) + 2;
+ creation_hash = src;
+ src += creation_hash_len;
+ if (src + 2 > end)
+ return -EINVAL;
+
+ /*
+ * The creation ticket (TPMT_TK_CREATION) consists of a 2 byte
+ * tag, 4 byte handle, and then a TPM2B_DIGEST, which is a 2
+ * byte length followed by data.
+ */
+ creation_tk_len = get_unaligned_be16(src + 6) + 8;
+ creation_tk = src;
+ if (creation_tk + creation_tk_len > end)
+ return -EINVAL;
+ }
if (!scratch)
return -ENOMEM;
@@ -63,26 +98,81 @@ static int tpm2_key_encode(struct trusted_key_payload *payload,
}
/*
- * Assume both octet strings will encode to a 2 byte definite length
+ * Assume each octet string will encode to a 2 byte definite length.
+ * Each optional octet string consumes one extra byte.
*
- * Note: For a well behaved TPM, this warning should never
- * trigger, so if it does there's something nefarious going on
+ * Note: For a well behaved TPM, this warning should never trigger, so
+ * if it does there's something nefarious going on
*/
- if (WARN(work - scratch + pub_len + priv_len + 14 > SCRATCH_SIZE,
- "BUG: scratch buffer is too small"))
- return -EINVAL;
+ if (WARN(work - scratch + pub_len + priv_len + creation_data_len +
+ creation_hash_len + creation_tk_len + (7 * 5) + 3 >
+ SCRATCH_SIZE,
+ "BUG: scratch buffer is too small")) {
+ rc = -EINVAL;
+ goto err;
+ }
work = asn1_encode_integer(work, end_work, options->keyhandle);
work = asn1_encode_octet_string(work, end_work, pub, pub_len);
work = asn1_encode_octet_string(work, end_work, priv, priv_len);
+ if (creation_data_len) {
+ u8 *scratch2 = kmalloc(SCRATCH_SIZE, GFP_KERNEL);
+ u8 *work2;
+ u8 *end_work2 = scratch2 + SCRATCH_SIZE;
+
+ if (!scratch2) {
+ rc = -ENOMEM;
+ goto err;
+ }
+
+ work2 = asn1_encode_octet_string(scratch2,
+ end_work2,
+ creation_data,
+ creation_data_len);
+
+ work = asn1_encode_tag(work,
+ end_work,
+ 1,
+ scratch2,
+ work2 - scratch2);
+
+ work2 = asn1_encode_octet_string(scratch2,
+ end_work2,
+ creation_hash,
+ creation_hash_len);
+
+ work = asn1_encode_tag(work,
+ end_work,
+ 2,
+ scratch2,
+ work2 - scratch2);
+
+ work2 = asn1_encode_octet_string(scratch2,
+ end_work2,
+ creation_tk,
+ creation_tk_len);
+
+ work = asn1_encode_tag(work,
+ end_work,
+ 3,
+ scratch2,
+ work2 - scratch2);
+
+ kfree(scratch2);
+ }
work1 = payload->blob;
work1 = asn1_encode_sequence(work1, work1 + sizeof(payload->blob),
scratch, work - scratch);
- if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed"))
- return PTR_ERR(work1);
+ if (WARN(IS_ERR(work1), "BUG: ASN.1 encoder failed")) {
+ rc = PTR_ERR(work1);
+ goto err;
+ }
return work1 - payload->blob;
+err:
+ kfree(scratch);
+ return rc;
}
struct tpm2_key_context {
@@ -91,15 +181,21 @@ struct tpm2_key_context {
u32 pub_len;
const u8 *priv;
u32 priv_len;
+ const u8 *creation_data;
+ u32 creation_data_len;
+ const u8 *creation_hash;
+ u32 creation_hash_len;
+ const u8 *creation_tk;
+ u32 creation_tk_len;
};
static int tpm2_key_decode(struct trusted_key_payload *payload,
- struct trusted_key_options *options,
- u8 **buf)
+ struct trusted_key_options *options)
{
+ u64 data_len;
int ret;
struct tpm2_key_context ctx;
- u8 *blob;
+ u8 *blob, *buf;
memset(&ctx, 0, sizeof(ctx));
@@ -108,21 +204,57 @@ static int tpm2_key_decode(struct trusted_key_payload *payload,
if (ret < 0)
return ret;
- if (ctx.priv_len + ctx.pub_len > MAX_BLOB_SIZE)
+ data_len = ctx.priv_len + ctx.pub_len + ctx.creation_data_len +
+ ctx.creation_hash_len + ctx.creation_tk_len;
+
+ if (data_len > MAX_BLOB_SIZE)
return -EINVAL;
- blob = kmalloc(ctx.priv_len + ctx.pub_len + 4, GFP_KERNEL);
- if (!blob)
+ buf = kmalloc(data_len + 4, GFP_KERNEL);
+ if (!buf)
return -ENOMEM;
- *buf = blob;
+ blob = buf;
options->keyhandle = ctx.parent;
memcpy(blob, ctx.priv, ctx.priv_len);
blob += ctx.priv_len;
memcpy(blob, ctx.pub, ctx.pub_len);
+ blob += ctx.pub_len;
+ if (ctx.creation_data_len) {
+ memcpy(blob, ctx.creation_data, ctx.creation_data_len);
+ blob += ctx.creation_data_len;
+ }
+
+ if (ctx.creation_hash_len) {
+ memcpy(blob, ctx.creation_hash, ctx.creation_hash_len);
+ blob += ctx.creation_hash_len;
+ }
+
+ if (ctx.creation_tk_len) {
+ memcpy(blob, ctx.creation_tk, ctx.creation_tk_len);
+ blob += ctx.creation_tk_len;
+ }
+
+ /*
+ * Copy the buffer back into the payload blob since the creation
+ * info will be used after loading.
+ */
+ payload->blob_len = blob - buf;
+ memcpy(payload->blob, buf, payload->blob_len);
+ if (ctx.creation_data_len) {
+ payload->creation = payload->blob + ctx.priv_len + ctx.pub_len;
+ payload->creation_len = ctx.creation_data_len;
+ payload->creation_hash = payload->creation + ctx.creation_data_len;
+ payload->creation_hash_len = ctx.creation_hash_len;
+ payload->tk = payload->creation_hash +
+ payload->creation_hash_len;
+
+ payload->tk_len = ctx.creation_tk_len;
+ }
+ kfree(buf);
return 0;
}
@@ -185,6 +317,42 @@ int tpm2_key_priv(void *context, size_t hdrlen,
return 0;
}
+int tpm2_key_creation_data(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key_context *ctx = context;
+
+ ctx->creation_data = value;
+ ctx->creation_data_len = vlen;
+
+ return 0;
+}
+
+int tpm2_key_creation_hash(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key_context *ctx = context;
+
+ ctx->creation_hash = value;
+ ctx->creation_hash_len = vlen;
+
+ return 0;
+}
+
+int tpm2_key_creation_tk(void *context, size_t hdrlen,
+ unsigned char tag,
+ const void *value, size_t vlen)
+{
+ struct tpm2_key_context *ctx = context;
+
+ ctx->creation_tk = value;
+ ctx->creation_tk_len = vlen;
+
+ return 0;
+}
+
/**
* tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
*
@@ -229,6 +397,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
struct trusted_key_options *options)
{
int blob_len = 0;
+ unsigned int offset;
struct tpm_buf buf;
u32 hash;
u32 flags;
@@ -317,13 +486,14 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
rc = -E2BIG;
goto out;
}
- if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
+ offset = TPM_HEADER_SIZE + 4;
+ if (tpm_buf_length(&buf) < offset + blob_len) {
rc = -EFAULT;
goto out;
}
blob_len = tpm2_key_encode(payload, options,
- &buf.data[TPM_HEADER_SIZE + 4],
+ &buf.data[offset],
blob_len);
out:
@@ -370,13 +540,11 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
int rc;
u32 attrs;
- rc = tpm2_key_decode(payload, options, &blob);
- if (rc) {
- /* old form */
- blob = payload->blob;
+ rc = tpm2_key_decode(payload, options);
+ if (rc)
payload->old_format = 1;
- }
+ blob = payload->blob;
/* new format carries keyhandle but old format doesn't */
if (!options->keyhandle)
return -EINVAL;
@@ -433,8 +601,6 @@ static int tpm2_load_cmd(struct tpm_chip *chip,
(__be32 *) &buf.data[TPM_HEADER_SIZE]);
out:
- if (blob != payload->blob)
- kfree(blob);
tpm_buf_destroy(&buf);
if (rc > 0)
--
2.38.1.431.g37b22c650d-goog
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v4 05/11] security: keys: trusted: Allow storage of PCR values in creation data
2022-11-03 18:01 [PATCH v4 00/11] Encrypted Hibernation Evan Green
2022-11-03 18:01 ` [PATCH v4 04/11] security: keys: trusted: Include TPM2 creation data Evan Green
@ 2022-11-03 18:01 ` Evan Green
2022-11-04 18:34 ` Kees Cook
2022-11-03 18:01 ` [PATCH v4 06/11] security: keys: trusted: Verify " Evan Green
2 siblings, 1 reply; 9+ messages in thread
From: Evan Green @ 2022-11-03 18:01 UTC (permalink / raw)
To: linux-kernel
Cc: corbet, linux-pm, rjw, gwendal, apronin, Pavel Machek, Kees Cook,
Matthew Garrett, linux-integrity, jejb, zohar, dlunev,
Eric Biggers, Ben Boeckel, jarkko, Matthew Garrett,
Matthew Garrett, Evan Green, Ben Boeckel, David Howells,
James Morris, Paul Moore, Serge E. Hallyn, keyrings, linux-doc,
linux-security-module
From: Matthew Garrett <matthewgarrett@google.com>
When TPMs generate keys, they can also generate some information
describing the state of the PCRs at creation time. This data can then
later be certified by the TPM, allowing verification of the PCR values.
This allows us to determine the state of the system at the time a key
was generated. Add an additional argument to the trusted key creation
options, allowing the user to provide the set of PCRs that should have
their values incorporated into the creation data.
Link: https://lore.kernel.org/lkml/20210220013255.1083202-6-matthewgarrett@google.com/
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Evan Green <evgreen@chromium.org>
Reviewed-by: Ben Boeckel <linux@me.benboeckel.net>
---
(no changes since v3)
Changes in v3:
- Clarified creationpcrs documentation (Ben)
.../security/keys/trusted-encrypted.rst | 6 +++++
include/keys/trusted-type.h | 1 +
security/keys/trusted-keys/trusted_tpm1.c | 9 +++++++
security/keys/trusted-keys/trusted_tpm2.c | 25 +++++++++++++++++--
4 files changed, 39 insertions(+), 2 deletions(-)
diff --git a/Documentation/security/keys/trusted-encrypted.rst b/Documentation/security/keys/trusted-encrypted.rst
index 9bc9db8ec6517c..a1872964fe862f 100644
--- a/Documentation/security/keys/trusted-encrypted.rst
+++ b/Documentation/security/keys/trusted-encrypted.rst
@@ -199,6 +199,12 @@ Usage::
policyhandle= handle to an authorization policy session that defines the
same policy and with the same hash algorithm as was used to
seal the key.
+ creationpcrs= hex integer representing the set of PCRs to be
+ included in the creation data. For each bit set, the
+ corresponding PCR will be included in the key creation
+ data. Bit 0 corresponds to PCR0. Currently only the first
+ PC standard 24 PCRs are supported on the currently active
+ bank. Leading zeroes are optional. TPM2 only.
"keyctl print" returns an ascii hex copy of the sealed key, which is in standard
TPM_STORED_DATA format. The key length for new keys are always in bytes.
diff --git a/include/keys/trusted-type.h b/include/keys/trusted-type.h
index 209086fed240a5..8523d41507b2a4 100644
--- a/include/keys/trusted-type.h
+++ b/include/keys/trusted-type.h
@@ -54,6 +54,7 @@ struct trusted_key_options {
uint32_t policydigest_len;
unsigned char policydigest[MAX_DIGEST_SIZE];
uint32_t policyhandle;
+ uint32_t creation_pcrs;
};
struct trusted_key_ops {
diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c
index aa108bea6739b3..2975827c01bec0 100644
--- a/security/keys/trusted-keys/trusted_tpm1.c
+++ b/security/keys/trusted-keys/trusted_tpm1.c
@@ -713,6 +713,7 @@ enum {
Opt_hash,
Opt_policydigest,
Opt_policyhandle,
+ Opt_creationpcrs,
};
static const match_table_t key_tokens = {
@@ -725,6 +726,7 @@ static const match_table_t key_tokens = {
{Opt_hash, "hash=%s"},
{Opt_policydigest, "policydigest=%s"},
{Opt_policyhandle, "policyhandle=%s"},
+ {Opt_creationpcrs, "creationpcrs=%s"},
{Opt_err, NULL}
};
@@ -858,6 +860,13 @@ static int getoptions(char *c, struct trusted_key_payload *pay,
return -EINVAL;
opt->policyhandle = handle;
break;
+ case Opt_creationpcrs:
+ if (!tpm2)
+ return -EINVAL;
+ res = kstrtoint(args[0].from, 16, &opt->creation_pcrs);
+ if (res < 0)
+ return -EINVAL;
+ break;
default:
return -EINVAL;
}
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index e1388d7d799a36..a7ad83bc0e5396 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -401,7 +401,7 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
struct tpm_buf buf;
u32 hash;
u32 flags;
- int i;
+ int i, j;
int rc;
for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
@@ -470,7 +470,28 @@ int tpm2_seal_trusted(struct tpm_chip *chip,
tpm_buf_append_u16(&buf, 0);
/* creation PCR */
- tpm_buf_append_u32(&buf, 0);
+ if (options->creation_pcrs) {
+ /* One bank */
+ tpm_buf_append_u32(&buf, 1);
+ /* Which bank to use */
+ tpm_buf_append_u16(&buf, hash);
+ /* Length of the PCR bitmask */
+ tpm_buf_append_u8(&buf, 3);
+ /* PCR bitmask */
+ for (i = 0; i < 3; i++) {
+ char tmp = 0;
+
+ for (j = 0; j < 8; j++) {
+ char bit = (i * 8) + j;
+
+ if (options->creation_pcrs & (1 << bit))
+ tmp |= (1 << j);
+ }
+ tpm_buf_append_u8(&buf, tmp);
+ }
+ } else {
+ tpm_buf_append_u32(&buf, 0);
+ }
if (buf.flags & TPM_BUF_OVERFLOW) {
rc = -E2BIG;
--
2.38.1.431.g37b22c650d-goog
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v4 06/11] security: keys: trusted: Verify creation data
2022-11-03 18:01 [PATCH v4 00/11] Encrypted Hibernation Evan Green
2022-11-03 18:01 ` [PATCH v4 04/11] security: keys: trusted: Include TPM2 creation data Evan Green
2022-11-03 18:01 ` [PATCH v4 05/11] security: keys: trusted: Allow storage of PCR values in " Evan Green
@ 2022-11-03 18:01 ` Evan Green
2022-11-04 18:35 ` Kees Cook
2 siblings, 1 reply; 9+ messages in thread
From: Evan Green @ 2022-11-03 18:01 UTC (permalink / raw)
To: linux-kernel
Cc: corbet, linux-pm, rjw, gwendal, apronin, Pavel Machek, Kees Cook,
Matthew Garrett, linux-integrity, jejb, zohar, dlunev,
Eric Biggers, Ben Boeckel, jarkko, Evan Green, Matthew Garrett,
David Howells, James Morris, Matthew Garrett, Paul Moore,
Serge E. Hallyn, axelj, keyrings, linux-security-module
If a loaded key contains creation data, ask the TPM to verify that
creation data. This allows users like encrypted hibernate to know that
the loaded and parsed creation data has not been tampered with.
Suggested-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Evan Green <evgreen@chromium.org>
---
Source material for this change is at:
https://patchwork.kernel.org/project/linux-pm/patch/20210220013255.1083202-9-matthewgarrett@google.com/
(no changes since v3)
Changes in v3:
- Changed funky tag to suggested-by (Kees). Matthew, holler if you want
something different.
Changes in v2:
- Adjust hash len by 2 due to new ASN.1 storage, and add underflow
check.
include/linux/tpm.h | 1 +
security/keys/trusted-keys/trusted_tpm2.c | 77 ++++++++++++++++++++++-
2 files changed, 77 insertions(+), 1 deletion(-)
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 70134e6551745f..9c2ee3e30ffa5d 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -224,6 +224,7 @@ enum tpm2_command_codes {
TPM2_CC_SELF_TEST = 0x0143,
TPM2_CC_STARTUP = 0x0144,
TPM2_CC_SHUTDOWN = 0x0145,
+ TPM2_CC_CERTIFYCREATION = 0x014A,
TPM2_CC_NV_READ = 0x014E,
TPM2_CC_CREATE = 0x0153,
TPM2_CC_LOAD = 0x0157,
diff --git a/security/keys/trusted-keys/trusted_tpm2.c b/security/keys/trusted-keys/trusted_tpm2.c
index a7ad83bc0e5396..c76a1b5a2e8471 100644
--- a/security/keys/trusted-keys/trusted_tpm2.c
+++ b/security/keys/trusted-keys/trusted_tpm2.c
@@ -703,6 +703,74 @@ static int tpm2_unseal_cmd(struct tpm_chip *chip,
return rc;
}
+/**
+ * tpm2_certify_creation() - execute a TPM2_CertifyCreation command
+ *
+ * @chip: TPM chip to use
+ * @payload: the key data in clear and encrypted form
+ * @blob_handle: the loaded TPM handle of the key
+ *
+ * Return: 0 on success
+ * -EINVAL on tpm error status
+ * < 0 error from tpm_send or tpm_buf_init
+ */
+static int tpm2_certify_creation(struct tpm_chip *chip,
+ struct trusted_key_payload *payload,
+ u32 blob_handle)
+{
+ struct tpm_header *head;
+ struct tpm_buf buf;
+ int rc;
+
+ rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CERTIFYCREATION);
+ if (rc)
+ return rc;
+
+ /* Use TPM_RH_NULL for signHandle */
+ tpm_buf_append_u32(&buf, 0x40000007);
+
+ /* Object handle */
+ tpm_buf_append_u32(&buf, blob_handle);
+
+ /* Auth */
+ tpm_buf_append_u32(&buf, 9);
+ tpm_buf_append_u32(&buf, TPM2_RS_PW);
+ tpm_buf_append_u16(&buf, 0);
+ tpm_buf_append_u8(&buf, 0);
+ tpm_buf_append_u16(&buf, 0);
+
+ /* Qualifying data */
+ tpm_buf_append_u16(&buf, 0);
+
+ /* Creation data hash */
+ if (payload->creation_hash_len < 2) {
+ rc = -EINVAL;
+ goto out;
+ }
+
+ tpm_buf_append_u16(&buf, payload->creation_hash_len - 2);
+ tpm_buf_append(&buf, payload->creation_hash + 2,
+ payload->creation_hash_len - 2);
+
+ /* signature scheme */
+ tpm_buf_append_u16(&buf, TPM_ALG_NULL);
+
+ /* creation ticket */
+ tpm_buf_append(&buf, payload->tk, payload->tk_len);
+
+ rc = tpm_transmit_cmd(chip, &buf, 6, "certifying creation data");
+ if (rc)
+ goto out;
+
+ head = (struct tpm_header *)buf.data;
+
+ if (be32_to_cpu(head->return_code) != TPM2_RC_SUCCESS)
+ rc = -EINVAL;
+out:
+ tpm_buf_destroy(&buf);
+ return rc;
+}
+
/**
* tpm2_unseal_trusted() - unseal the payload of a trusted key
*
@@ -728,8 +796,15 @@ int tpm2_unseal_trusted(struct tpm_chip *chip,
goto out;
rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
- tpm2_flush_context(chip, blob_handle);
+ if (rc)
+ goto flush;
+
+ if (payload->creation_len)
+ rc = tpm2_certify_creation(chip, payload, blob_handle);
+
+flush:
+ tpm2_flush_context(chip, blob_handle);
out:
tpm_put_ops(chip);
--
2.38.1.431.g37b22c650d-goog
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