1 /* $NetBSD: mech_crammd5.c,v 1.4 2011/02/12 23:21:32 christos Exp $ */
2
3 /* Copyright (c) 2010 The NetBSD Foundation, Inc.
4 * All rights reserved.
5 *
6 * This code is derived from software contributed to The NetBSD Foundation
7 * by Mateusz Kocielski.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the NetBSD
20 * Foundation, Inc. and its contributors.
21 * 4. Neither the name of The NetBSD Foundation nor the names of its
22 * contributors may be used to endorse or promote products derived
23 * from this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
26 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37 #include <sys/cdefs.h>
38 __RCSID("$NetBSD: mech_crammd5.c,v 1.4 2011/02/12 23:21:32 christos Exp $");
39
40 #include <sys/param.h>
41
42 #include <saslc.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46
47 #include "crypto.h"
48 #include "mech.h"
49 #include "saslc_private.h"
50
51
52 /* See RFC 2195. */
53
54 /* properties */
55 #define SASLC_CRAMMD5_AUTHCID SASLC_PROP_AUTHCID
56 #define SASLC_CRAMMD5_PASSWD SASLC_PROP_PASSWD
57
58 /**
59 * @brief do one step of the sasl authentication
60 * @param sess sasl session
61 * @param in input data
62 * @param inlen input data length
63 * @param out place to store output data
64 * @param outlen output data length
65 * @return MECH_OK - success,
66 * MECH_STEP - more steps are needed,
67 * MECH_ERROR - error
68 */
69 static int
saslc__mech_crammd5_cont(saslc_sess_t * sess,const void * in,size_t inlen,void ** out,size_t * outlen)70 saslc__mech_crammd5_cont(saslc_sess_t *sess, const void *in, size_t inlen,
71 void **out, size_t *outlen)
72 {
73 const char *authcid, *passwd;
74 char *digest, *name;
75 int len, rv;
76
77 /* in case we are called before getting challenge from server */
78 if (inlen == 0) {
79 *out = NULL;
80 *outlen = 0;
81 return MECH_STEP;
82 }
83 if ((authcid = saslc_sess_getprop(sess, SASLC_CRAMMD5_AUTHCID))
84 == NULL) {
85 saslc__error_set(ERR(sess), ERROR_MECH,
86 "authcid is required for an authentication");
87 return MECH_ERROR;
88 }
89 if ((passwd = saslc_sess_getprop(sess, SASLC_CRAMMD5_PASSWD))
90 == NULL) {
91 saslc__error_set(ERR(sess), ERROR_MECH,
92 "passwd is required for an authentication");
93 return MECH_ERROR;
94 }
95 digest = saslc__crypto_hmac_md5_hex((const unsigned char *)passwd,
96 strlen(passwd), in, inlen);
97 if (digest == NULL) {
98 saslc__error_set_errno(ERR(sess), ERROR_NOMEM);
99 return MECH_ERROR;
100 }
101 if ((len = asprintf(&name, "%s %s", authcid, digest)) == -1) {
102 saslc__error_set_errno(ERR(sess), ERROR_NOMEM);
103 rv = MECH_ERROR;
104 }
105 else {
106 *out = name;
107 *outlen = len; /* don't count the '\0' byte */
108 rv = MECH_OK;
109 }
110 memset(digest, 0, HMAC_MD5_DIGEST_LENGTH);
111 free(digest);
112 return rv;
113 }
114
115 /* mechanism definition */
116 const saslc__mech_t saslc__mech_crammd5 = {
117 .name = "CRAM-MD5",
118 .flags = FLAG_DICTIONARY,
119 .create = saslc__mech_generic_create,
120 .cont = saslc__mech_crammd5_cont,
121 .encode = NULL,
122 .decode = NULL,
123 .destroy = saslc__mech_generic_destroy
124 };
125