(md5_init): Use memcpy for initializing the state vector.

(COMPRESS): New macro, wrapping _nettle_md5_compress.
(md5_update): Use MD_UPDATE.
(md5_digest): Inline md5_final processing. Use MD_PAD and
_nettle_write_le32.
(md5_final): Deleted.

Rev: nettle/md5.c:1.3

md5.c

@@ -38,110 +38,50 @@
 #include "macros.h"
 #include "nettle-write.h"
 
-static void
-md5_final(struct md5_ctx *ctx);
-
 void
 md5_init(struct md5_ctx *ctx)
 {
-  ctx->digest[0] = 0x67452301;
-  ctx->digest[1] = 0xefcdab89;
-  ctx->digest[2] = 0x98badcfe;
-  ctx->digest[3] = 0x10325476;
-  
-  ctx->count_l = ctx->count_h = 0;
+  const uint32_t iv[_MD5_DIGEST_LENGTH] =
+    {
+      0x67452301,
+      0xefcdab89,
+      0x98badcfe,
+      0x10325476,
+    };
+  memcpy(ctx->state, iv, sizeof(ctx->state));
+  ctx->count_low = ctx->count_high = 0;
   ctx->index = 0;
 }
 
-#define MD5_INCR(ctx) ((ctx)->count_h += !++(ctx)->count_l)
+#define COMPRESS(ctx, data) (_nettle_md5_compress((ctx)->state, (data)))
 
 void
 md5_update(struct md5_ctx *ctx,
 	   unsigned length,
 	   const uint8_t *data)
 {
-  if (ctx->index)
-    {
-      /* Try to fill partial block */
-      unsigned left = MD5_DATA_SIZE - ctx->index;
-      if (length < left)
-	{
-	  memcpy(ctx->block + ctx->index, data, length);
-	  ctx->index += length;
-	  return; /* Finished */
-	}
-      else
-	{
-	  memcpy(ctx->block + ctx->index, data, left);
-
-	  _nettle_md5_compress(ctx->digest, ctx->block);
-	  MD5_INCR(ctx);
-	  
-	  data += left;
-	  length -= left;
-	}
-    }
-  while (length >= MD5_DATA_SIZE)
-    {
-      _nettle_md5_compress(ctx->digest, data);
-      MD5_INCR(ctx);
-
-      data += MD5_DATA_SIZE;
-      length -= MD5_DATA_SIZE;
-    }
-  if ((ctx->index = length))     /* This assignment is intended */
-    /* Buffer leftovers */
-    memcpy(ctx->block, data, length);
+  MD_UPDATE(ctx, length, data, COMPRESS, MD_INCR(ctx));
 }
 
 void
 md5_digest(struct md5_ctx *ctx,
 	   unsigned length,
 	   uint8_t *digest)
-{  
-  assert(length <= MD5_DIGEST_SIZE);
-
-  md5_final(ctx);
-  _nettle_write_le32(length, digest, ctx->digest);
-  md5_init(ctx);
-}
-
-/* Final wrapup - pad to MD5_DATA_SIZE-byte boundary with the bit
- * pattern 1 0* (64-bit count of bits processed, LSB-first) */
-
-static void
-md5_final(struct md5_ctx *ctx)
 {
-  uint32_t bitcount_high;
-  uint32_t bitcount_low;
-  unsigned i;
+  uint32_t high, low;
   
-  i = ctx->index;
+  assert(length <= MD5_DIGEST_SIZE);
 
-  /* Set the first char of padding to 0x80. This is safe since there
-   * is always at least one byte free */
-  assert(i < MD5_DATA_SIZE);
-  ctx->block[i++] = 0x80;
+  MD_PAD(ctx, 8, COMPRESS);
 
-  if (i > (MD5_DATA_SIZE - 8))
-    {
-      /* No room for length in this block. Process it and
-	 pad with another one */
-      memset(ctx->block + i, 0, MD5_DATA_SIZE - i);
-      
-      _nettle_md5_compress(ctx->digest, ctx->block);
-      i = 0;
-    }
-  if (i < (MD5_DATA_SIZE - 8))
-    memset(ctx->block + i, 0, (MD5_DATA_SIZE - 8) - i);
-    
-  /* There are 512 = 2^9 bits in one block 
-   * Little-endian order => Least significant word first */
+  /* There are 512 = 2^9 bits in one block */  
+  high = (ctx->count_high << 9) | (ctx->count_low >> 23);
+  low = (ctx->count_low << 9) | (ctx->index << 3);
 
-  bitcount_low = (ctx->count_l << 9) | (ctx->index << 3);
-  bitcount_high = (ctx->count_h << 9) | (ctx->count_l >> 23);
-  LE_WRITE_UINT32(ctx->block + (MD5_DATA_SIZE - 8), bitcount_low);
-  LE_WRITE_UINT32(ctx->block + (MD5_DATA_SIZE - 4), bitcount_high);
-  
-  _nettle_md5_compress(ctx->digest, ctx->block);
+  LE_WRITE_UINT32(ctx->block + (MD5_DATA_SIZE - 8), low);
+  LE_WRITE_UINT32(ctx->block + (MD5_DATA_SIZE - 4), high);
+  _nettle_md5_compress(ctx->state, ctx->block);
+
+  _nettle_write_le32(length, digest, ctx->state);
+  md5_init(ctx);
 }