1 /* hmac-sha1.c -- hashed message authentication codes
2 Copyright (C) 2005 Free Software Foundation, Inc.
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2, or (at your option)
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software Foundation,
16 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 /* Written by Simon Josefsson. */
35 hmac_sha1 (const void *key, size_t keylen,
36 const void *in, size_t inlen, void *resbuf)
38 struct sha1_ctx inner;
39 struct sha1_ctx outer;
46 struct sha1_ctx keyhash;
48 sha1_init_ctx (&keyhash);
49 sha1_process_bytes (key, keylen, &keyhash);
50 sha1_finish_ctx (&keyhash, optkeybuf);
56 sha1_init_ctx (&inner);
58 memset (block, IPAD, sizeof (block));
59 memxor (block, key, keylen);
61 sha1_process_block (block, 64, &inner);
62 sha1_process_bytes (in, inlen, &inner);
64 sha1_finish_ctx (&inner, innerhash);
66 sha1_init_ctx (&outer);
68 memset (block, OPAD, sizeof (block));
69 memxor (block, key, keylen);
71 sha1_process_block (block, 64, &outer);
72 sha1_process_bytes (innerhash, 20, &outer);
74 sha1_finish_ctx (&outer, resbuf);