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-rw-r--r--libsylph/md5_hmac.c135
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+/*
+ * 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';
+}