Fix packet authentication.

[tinc] / src / gcrypt / digest.c

diff --git a/src/gcrypt/digest.c b/src/gcrypt/digest.c
index 34f9d28..066600f 100644 (file)
--- a/src/gcrypt/digest.c
+++ b/src/gcrypt/digest.c
@@ -87,6 +87,7 @@ static bool digest_open(digest_t *digest, int algo, int maclength) {
                digest->maclength = maclength;
        
        digest->algo = algo;
+       digest->hmac = NULL;
 
        return true;
 }
@@ -118,24 +119,45 @@ bool digest_open_sha1(digest_t *digest, int maclength) {
 }
 
 void digest_close(digest_t *digest) {
+       if(digest->hmac)
+               gcry_md_close(digest->hmac);
+       digest->hmac = NULL;
+}
+
+bool digest_set_key(digest_t *digest, const void *key, size_t len) {
+       if(!digest->hmac)
+               gcry_md_open(&digest->hmac, digest->algo, GCRY_MD_FLAG_HMAC);
+       if(!digest->hmac)
+               return false;
+
+       return !gcry_md_setkey(digest->hmac, key, len);
 }
 
 bool digest_create(digest_t *digest, const void *indata, size_t inlen, void *outdata) {
        unsigned int len = gcry_md_get_algo_dlen(digest->algo);
-       char tmpdata[len];
 
-       gcry_md_hash_buffer(digest->algo, tmpdata, indata, inlen);
-       memcpy(outdata, tmpdata, digest->maclength);
+       if(digest->hmac) {
+               char *tmpdata;
+               gcry_md_reset(digest->hmac);
+               gcry_md_write(digest->hmac, indata, inlen);
+               tmpdata = gcry_md_read(digest->hmac, digest->algo);
+               if(!tmpdata)
+                       return false;
+               memcpy(outdata, tmpdata, digest->maclength);
+       } else {
+               char tmpdata[len];
+               gcry_md_hash_buffer(digest->algo, tmpdata, indata, inlen);
+               memcpy(outdata, tmpdata, digest->maclength);
+       }
 
        return true;
 }
 
 bool digest_verify(digest_t *digest, const void *indata, size_t inlen, const void *cmpdata) {
-       unsigned int len = gcry_md_get_algo_dlen(digest->algo);
+       unsigned int len = digest->maclength;
        char outdata[len];
 
-       gcry_md_hash_buffer(digest->algo, outdata, indata, inlen);
-       return !memcmp(cmpdata, outdata, digest->maclength);
+       return digest_create(digest, indata, inlen, outdata) && !memcmp(cmpdata, outdata, len);
 }
 
 int digest_get_nid(const digest_t *digest) {