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 */
69static int
70saslc__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 */
116const 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