Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[linux.git] / crypto / asymmetric_keys / pkcs7_verify.c

diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c
index 11bee67fa9ccefab8ae89ce9cc6509c75c7ddbf2..ce49820caa97fb885766798060677361742f3645 100644 (file)
--- a/crypto/asymmetric_keys/pkcs7_verify.c
+++ b/crypto/asymmetric_keys/pkcs7_verify.c
@@ -12,6 +12,7 @@
 #include <linux/err.h>
 #include <linux/asn1.h>
 #include <crypto/hash.h>
+#include <crypto/hash_info.h>
 #include <crypto/public_key.h>
 #include "pkcs7_parser.h"
 
@@ -29,6 +30,10 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
 
        kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo);
 
+       /* The digest was calculated already. */
+       if (sig->digest)
+               return 0;
+
        if (!sinfo->sig->hash_algo)
                return -ENOPKG;
 
@@ -117,6 +122,34 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7,
        return ret;
 }
 
+int pkcs7_get_digest(struct pkcs7_message *pkcs7, const u8 **buf, u32 *len,
+                    enum hash_algo *hash_algo)
+{
+       struct pkcs7_signed_info *sinfo = pkcs7->signed_infos;
+       int i, ret;
+
+       /*
+        * This function doesn't support messages with more than one signature.
+        */
+       if (sinfo == NULL || sinfo->next != NULL)
+               return -EBADMSG;
+
+       ret = pkcs7_digest(pkcs7, sinfo);
+       if (ret)
+               return ret;
+
+       *buf = sinfo->sig->digest;
+       *len = sinfo->sig->digest_size;
+
+       for (i = 0; i < HASH_ALGO__LAST; i++)
+               if (!strcmp(hash_algo_name[i], sinfo->sig->hash_algo)) {
+                       *hash_algo = i;
+                       break;
+               }
+
+       return 0;
+}
+
 /*
  * Find the key (X.509 certificate) to use to verify a PKCS#7 message.  PKCS#7
  * uses the issuer's name and the issuing certificate serial number for