[PATCH 05/16] integrity: Export a function to retrieve hash algo used in digital signature

Vivek Goyal
2013-09-10T21:45:02Z

A function to retrieve hash algo used in digital signature.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
---
security/integrity/digsig.c | 26 ++++++++++++++++++++++++++
security/integrity/integrity.h | 7 +++++++
2 files changed, 33 insertions(+)

diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index f1259bd..153cff4 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -16,6 +16,8 @@
#include <linux/rbtree.h>
#include <linux/key-type.h>
#include <linux/digsig.h>
+#include <crypto/hash.h>
+#include <crypto/public_key.h>

#include "integrity.h"

@@ -27,6 +29,30 @@ static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
"_ima",
};

+int integrity_digsig_get_hash_algo(char *sig)
+{
+ uint8_t hash_algo;
+
+ if (sig[0] == 1) {
+ hash_algo = ((struct signature_hdr *)sig)->hash;
+ switch (hash_algo) {
+ case 0:
+ return PKEY_HASH_SHA1;
+ case 1:
+ return PKEY_HASH_SHA256;
+ default:
+ return -ENOPKG;
+ }
+ } else if (sig[0] == 2 ) {
+ hash_algo = ((struct signature_v2_hdr *)sig)->hash_algo;
+ if (hash_algo >= PKEY_HASH__LAST)
+ return -ENOPKG;
+ return hash_algo;
+ }
+
+ return -EBADMSG;
+}
+
/* Get size of digital signature */
int integrity_get_digsig_size(char *sig)
{
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 130eb3b..284bb8d 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -15,6 +15,7 @@
#include <linux/integrity.h>
#include <crypto/sha.h>
#include <linux/key.h>
+#include <crypto/public_key.h>

/* iint action cache flags */
#define IMA_MEASURE 0x00000001
@@ -105,8 +106,14 @@ int integrity_digsig_verify_keyring(struct key *keyring, const char *sig,
int siglen, const char *digest, int digestlen);
extern int integrity_get_digsig_size(char *sig);

+extern int integrity_digsig_get_hash_algo(char *sig);
#else

+static inline int integrity_digsig_get_hash_algo(char *sig)
+{
+ return -EOPNOTSUPP;
+}
+
static inline int integrity_digsig_verify(const unsigned int id,
const char *sig, int siglen,
const char *digest, int digestlen)
--
1.8.3.1