[PATCH v5 01/10] IMA: Added KEYRING_CHECK func in IMA policy to measure keys

Lakshmi Ramasubramanian
2019-11-11T19:33:11Z

IMA policy needs to support a func to enable measurement of
asymmetric keys.

This patch defines a new IMA policy func namely KEYRING_CHECK to
measure asymmetric keys.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
---
Documentation/ABI/testing/ima_policy | 6 ++++++
security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_policy.c | 4 +++-
3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy
index 29aaedf33246..341df49b5ad1 100644
--- a/Documentation/ABI/testing/ima_policy
+++ b/Documentation/ABI/testing/ima_policy
@@ -30,6 +30,7 @@ Description:
[FIRMWARE_CHECK]
[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
[KEXEC_CMDLINE]
+ [KEYRING_CHECK]
mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
[[^]MAY_EXEC]
fsmagic:= hex value
@@ -113,3 +114,8 @@ Description:
Example of appraise rule allowing modsig appended signatures:

appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
+
+ Example of measure rule using KEYRING_CHECK to measure
+ all keys:
+
+ measure func=KEYRING_CHECK
diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index df4ca482fb53..7f23405b2718 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -193,6 +193,7 @@ static inline unsigned long ima_hash_key(u8 *digest)
hook(KEXEC_INITRAMFS_CHECK) \
hook(POLICY_CHECK) \
hook(KEXEC_CMDLINE) \
+ hook(KEYRING_CHECK) \
hook(MAX_CHECK)
#define __ima_hook_enumify(ENUM) ENUM,

diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
index f19a895ad7cd..9ca32ffaaa9d 100644
--- a/security/integrity/ima/ima_policy.c
+++ b/security/integrity/ima/ima_policy.c
@@ -373,7 +373,7 @@ static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
{
int i;

- if (func == KEXEC_CMDLINE) {
+ if ((func == KEXEC_CMDLINE) || (func == KEYRING_CHECK)) {
if ((rule->flags & IMA_FUNC) && (rule->func == func))
return true;
return false;
@@ -997,6 +997,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
entry->func = POLICY_CHECK;
else if (strcmp(args[0].from, "KEXEC_CMDLINE") == 0)
entry->func = KEXEC_CMDLINE;
+ else if (strcmp(args[0].from, "KEYRING_CHECK") == 0)
+ entry->func = KEYRING_CHECK;
else
result = -EINVAL;
if (!result)
--
2.17.1