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Diffstat (limited to 'libsylph/md5_hmac.c')
| -rw-r--r-- | libsylph/md5_hmac.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/libsylph/md5_hmac.c b/libsylph/md5_hmac.c new file mode 100644 index 00000000..46c0f523 --- /dev/null +++ b/libsylph/md5_hmac.c @@ -0,0 +1,135 @@ +/* + * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client + * Copyright (C) 1999-2005 Hiroyuki Yamamoto + * + * 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 2, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include <glib.h> +#include <string.h> + +#include "md5.h" +#include "md5_hmac.h" + +/* +** Function: md5_hmac_get +** taken from the file rfc2104.txt +** originally written by Martin Schaaf <mascha@ma-scha.de> +** rewritten by Hiroyuki Yamamoto <hiro-y@kcn.ne.jp> +*/ +static SMD5* +md5_hmac_get(const guchar *text, gint text_len, + const guchar *key, gint key_len) +{ + SMD5 *md5; + guchar k_ipad[64]; /* inner padding - + * key XORd with ipad + */ + guchar k_opad[64]; /* outer padding - + * key XORd with opad + */ + guchar digest[S_GNET_MD5_HASH_LENGTH]; + gint i; + + /* start out by storing key in pads */ + memset(k_ipad, 0, sizeof k_ipad); + memset(k_opad, 0, sizeof k_opad); + + if (key_len > 64) { + /* if key is longer than 64 bytes reset it to key=MD5(key) */ + SMD5 *tmd5; + + tmd5 = s_gnet_md5_new_incremental(); + s_gnet_md5_update(tmd5, key, key_len); + s_gnet_md5_final(tmd5); + memcpy(k_ipad, s_gnet_md5_get_digest(tmd5), + S_GNET_MD5_HASH_LENGTH); + memcpy(k_opad, s_gnet_md5_get_digest(tmd5), + S_GNET_MD5_HASH_LENGTH); + s_gnet_md5_delete(tmd5); + } else { + memcpy(k_ipad, key, key_len); + memcpy(k_opad, key, key_len); + } + + /* + * the HMAC_MD5 transform looks like: + * + * MD5(K XOR opad, MD5(K XOR ipad, text)) + * + * where K is an n byte key + * ipad is the byte 0x36 repeated 64 times + * opad is the byte 0x5c repeated 64 times + * and text is the data being protected + */ + + + /* XOR key with ipad and opad values */ + for (i = 0; i < 64; i++) { + k_ipad[i] ^= 0x36; + k_opad[i] ^= 0x5c; + } + + /* + * perform inner MD5 + */ + md5 = s_gnet_md5_new_incremental(); /* init context for 1st + * pass */ + s_gnet_md5_update(md5, k_ipad, 64); /* start with inner pad */ + s_gnet_md5_update(md5, text, text_len); /* then text of datagram */ + s_gnet_md5_final(md5); /* finish up 1st pass */ + memcpy(digest, s_gnet_md5_get_digest(md5), S_GNET_MD5_HASH_LENGTH); + s_gnet_md5_delete(md5); + + /* + * perform outer MD5 + */ + md5 = s_gnet_md5_new_incremental(); /* init context for 2nd + * pass */ + s_gnet_md5_update(md5, k_opad, 64); /* start with outer pad */ + s_gnet_md5_update(md5, digest, 16); /* then results of 1st + * hash */ + s_gnet_md5_final(md5); /* finish up 2nd pass */ + + return md5; +} + +void +md5_hmac(guchar *digest, + const guchar *text, gint text_len, + const guchar *key, gint key_len) +{ + SMD5 *md5; + + md5 = md5_hmac_get(text, text_len, key, key_len); + memcpy(digest, s_gnet_md5_get_digest(md5), S_GNET_MD5_HASH_LENGTH); + s_gnet_md5_delete(md5); +} + +void +md5_hex_hmac(gchar *hexdigest, + const guchar *text, gint text_len, + const guchar *key, gint key_len) +{ + SMD5 *md5; + + md5 = md5_hmac_get(text, text_len, key, key_len); + s_gnet_md5_copy_string(md5, hexdigest); + hexdigest[S_GNET_MD5_HASH_LENGTH * 2] = '\0'; +} |