X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fhmac-md5.c;h=3f8b82787124b2f55eebf13fe082b151220ea77e;hb=bed5facc8ba8813aec741ae883a5021f4bc6339e;hp=ecd071496049b0e23d75b83712aa80cf00ac92c9;hpb=11ad180881e62f7d8758936af419c2cc88e9cf79;p=gnulib.git

diff --git a/lib/hmac-md5.c b/lib/hmac-md5.c
index ecd071496..3f8b82787 100644
--- a/lib/hmac-md5.c
+++ b/lib/hmac-md5.c
@@ -1,5 +1,5 @@
 /* hmac-md5.c -- hashed message authentication codes
-   Copyright (C) 2005 Free Software Foundation, Inc.
+   Copyright (C) 2005-2006, 2009-2012 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -12,14 +12,11 @@
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
-   along with this program; if not, write to the Free Software Foundation,
-   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
 
 /* Written by Simon Josefsson.  */
 
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
+#include <config.h>
 
 #include "hmac.h"
 
@@ -33,7 +30,7 @@
 
 int
 hmac_md5 (const void *key, size_t keylen,
-	  const void *in, size_t inlen, void *resbuf)
+          const void *in, size_t inlen, void *resbuf)
 {
   struct md5_ctx inner;
   struct md5_ctx outer;
@@ -41,6 +38,8 @@ hmac_md5 (const void *key, size_t keylen,
   char block[64];
   char innerhash[16];
 
+  /* Reduce the key's size, so that it becomes <= 64 bytes large.  */
+
   if (keylen > 64)
     {
       struct md5_ctx keyhash;
@@ -53,6 +52,8 @@ hmac_md5 (const void *key, size_t keylen,
       keylen = 16;
     }
 
+  /* Compute INNERHASH from KEY and IN.  */
+
   md5_init_ctx (&inner);
 
   memset (block, IPAD, sizeof (block));
@@ -63,6 +64,8 @@ hmac_md5 (const void *key, size_t keylen,
 
   md5_finish_ctx (&inner, innerhash);
 
+  /* Compute result from KEY and INNERHASH.  */
+
   md5_init_ctx (&outer);
 
   memset (block, OPAD, sizeof (block));