KEYS: Call the IMA hook to measure keys

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>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

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);

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 @@ error:
 	}
 
 	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);