gosthash2012: Simplify `pad'

[openssl-gost/engine.git] / gosthash2012.c

diff --git a/gosthash2012.c b/gosthash2012.c
index e94273df0635022fa38c99e921fc97a76b178629..201fe317ec23fb954e023c6b7a9fc48b5b0993eb 100644 (file)
--- a/gosthash2012.c
+++ b/gosthash2012.c
@@ -35,21 +35,22 @@ void init_gost2012_hash_ctx(gost2012_hash_ctx * CTX,
     memset(CTX, 0, sizeof(gost2012_hash_ctx));
 
     CTX->digest_size = digest_size;
+    /*
+     * IV for 512-bit hash should be 0^512
+     * IV for 256-bit hash should be (00000001)^64
+     *
+     * It's already zeroed when CTX is cleared above, so we only
+     * need to set it to 0x01-s for 256-bit hash.
+     */
     if (digest_size == 256)
         memset(&CTX->h, 0x01, sizeof(uint512_u));
-    else
-        memset(&CTX->h, 0x00, sizeof(uint512_u));
 }
 
 static INLINE void pad(gost2012_hash_ctx * CTX)
 {
-    unsigned char buf[64];
-
-    memset(&buf, 0x00, sizeof buf);
-    memcpy(&buf, CTX->buffer, CTX->bufsize);
+    memset(&(CTX->buffer[CTX->bufsize]), 0, sizeof(CTX->buffer) - CTX->bufsize);
+    CTX->buffer[CTX->bufsize] = 1;
 
-    buf[CTX->bufsize] = 0x01;
-    memcpy(CTX->buffer, &buf, sizeof buf);
 }
 
 static INLINE void add512(const union uint512_u *x,