[PATCH v11 4/6] KEYS: Call the IMA hook to measure keys

Lakshmi Ramasubramanian
2019-12-11T16:47:41Z

Call the IMA hook from key_create_or_update() function to measure
the payload when a new key is created or an existing key is updated.

This patch adds the call to the IMA hook from key_create_or_update()
function to measure the key on key create or update.

Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
include/linux/ima.h | 14 ++++++++++++++
security/keys/key.c | 10 ++++++++++
2 files changed, 24 insertions(+)

diff --git a/include/linux/ima.h b/include/linux/ima.h
index 6d904754d858..3b89136bc218 100644
--- a/include/linux/ima.h
+++ b/include/linux/ima.h
@@ -101,6 +101,20 @@ static inline void ima_add_kexec_buffer(struct kimage *image)
{}
#endif

+#if defined(CONFIG_IMA) && defined(CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE)
+extern void ima_post_key_create_or_update(struct key *keyring,
+ struct key *key,
+ const void *payload, size_t plen,
+ unsigned long flags, bool create);
+#else
+static inline void ima_post_key_create_or_update(struct key *keyring,
+ struct key *key,
+ const void *payload,
+ size_t plen,
+ unsigned long flags,
+ bool create) {}
+#endif /* CONFIG_IMA && CONFIG_ASYMMETRIC_PUBLIC_KEY_SUBTYPE */
+
#ifdef CONFIG_IMA_APPRAISE
extern bool is_ima_appraise_enabled(void);
extern void ima_inode_post_setattr(struct dentry *dentry);
diff --git a/security/keys/key.c b/security/keys/key.c
index 764f4c57913e..718bf7217420 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -13,6 +13,7 @@
#include <linux/security.h>
#include <linux/workqueue.h>
#include <linux/random.h>
+#include <linux/ima.h>
#include <linux/err.h>
#include "internal.h"

@@ -936,6 +937,9 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
goto error_link_end;
}

+ ima_post_key_create_or_update(keyring, key, payload, plen,
+ flags, true);
+
key_ref = make_key_ref(key, is_key_possessed(keyring_ref));

error_link_end:
@@ -965,6 +969,12 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
}

key_ref = __key_update(key_ref, &prep);
+
+ if (!IS_ERR(key_ref))
+ ima_post_key_create_or_update(keyring, key,
+ payload, plen,
+ flags, false);
+
goto error_free_prep;
}
EXPORT_SYMBOL(key_create_or_update);
--
2.17.1