1 files changed, 81 insertions, 0 deletions
diff --git a/libextra/gl/hmac-md5.c b/libextra/gl/hmac-md5.c
new file mode 100644
index 0000000000..a6811c275c
--- /dev/null
+++ b/libextra/gl/hmac-md5.c
@@ -0,0 +1,81 @@
+/* hmac-md5.c -- hashed message authentication codes
+   Copyright (C) 2005, 2006 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
+   the Free Software Foundation; either version 3, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   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.  */
+
+/* Written by Simon Josefsson.  */
+
+#include <config.h>
+
+#include "hmac.h"
+
+#include "memxor.h"
+#include "md5.h"
+
+#include <string.h>
+
+#define IPAD 0x36
+#define OPAD 0x5c
+
+int
+hmac_md5 (const void *key, size_t keylen,
+	  const void *in, size_t inlen, void *resbuf)
+{
+  struct md5_ctx inner;
+  struct md5_ctx outer;
+  char optkeybuf[16];
+  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;
+
+      md5_init_ctx (&keyhash);
+      md5_process_bytes (key, keylen, &keyhash);
+      md5_finish_ctx (&keyhash, optkeybuf);
+
+      key = optkeybuf;
+      keylen = 16;
+    }
+
+  /* Compute INNERHASH from KEY and IN.  */
+
+  md5_init_ctx (&inner);
+
+  memset (block, IPAD, sizeof (block));
+  memxor (block, key, keylen);
+
+  md5_process_block (block, 64, &inner);
+  md5_process_bytes (in, inlen, &inner);
+
+  md5_finish_ctx (&inner, innerhash);
+
+  /* Compute result from KEY and INNERHASH.  */
+
+  md5_init_ctx (&outer);
+
+  memset (block, OPAD, sizeof (block));
+  memxor (block, key, keylen);
+
+  md5_process_block (block, 64, &outer);
+  md5_process_bytes (innerhash, 16, &outer);
+
+  md5_finish_ctx (&outer, resbuf);
+
+  return 0;
+}