[PATCH RFC 05/12] integrity: Introduce mok keyring

Eric Snowberg
2021-07-07T02:45:17Z

Introduce a new keyring called mok. This keyring will be used during
boot. Afterwards it will be destroyed.

Follow on patches will use this keyring to load trusted MOK keys.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
security/integrity/Makefile | 3 ++-
security/integrity/digsig.c | 1 +
security/integrity/integrity.h | 7 ++++-
security/integrity/platform_certs/load_uefi.c | 1 +
.../integrity/platform_certs/mok_keyring.c | 26 +++++++++++++++++++
5 files changed, 36 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 a8436c6b93ec..56800a5f1e10 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 f801b2076f01..5126c80bd0d4 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;

@@ -282,9 +283,13 @@ 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 destroy_mok_keyring(void);
#else
static inline void __init add_to_platform_keyring(const char *source,
const void *data, size_t len)
{
}
+static inline void __init destroy_mok_keyring(void)
+{
+}
#endif
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index f290f78c3f30..94faa4b32441 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -193,6 +193,7 @@ static int __init load_uefi_certs(void)

/* Load the MokListRT certs */
rc = load_moklist_certs();
+ destroy_mok_keyring();

return rc;
}
diff --git a/security/integrity/platform_certs/mok_keyring.c b/security/integrity/platform_certs/mok_keyring.c
new file mode 100644
index 000000000000..2b0d17caf8fd
--- /dev/null
+++ b/security/integrity/platform_certs/mok_keyring.c
@@ -0,0 +1,26 @@
+// 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);
+
+void __init destroy_mok_keyring(void)
+{
+ return integrity_destroy_keyring(INTEGRITY_KEYRING_MOK);
+}
--
2.18.4