xref: /netbsd-src/crypto/external/bsd/libsaslc/dist/src/mech_crammd5.c (revision c2f76ff004a2cb67efe5b12d97bd3ef7fe89e18d)
1 /* $Id: mech_crammd5.c,v 1.1.1.1 2010/11/27 21:23:59 agc 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 
38 #include <saslc.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <string.h>
42 #include "saslc_private.h"
43 #include "mech.h"
44 #include "crypto.h"
45 
46 /* local headers */
47 
48 /* properties */
49 #define SASLC_CRAM_MD5_AUTHID		"AUTHID"
50 #define SASLC_CRAM_MD5_PASSWORD		"PASSWD"
51 
52 static int saslc__mech_crammd5_cont(saslc_sess_t *, const void *, size_t,
53     void **, size_t *);
54 
55 /**
56  * @brief doing one step of the sasl authentication
57  * @param sess sasl session
58  * @param in input data
59  * @param inlen input data length
60  * @param out place to store output data
61  * @param outlen output data length
62  * @return MECH_OK - success,
63  * MECH_STEP - more steps are needed,
64  * MECH_ERROR - error
65  */
66 
67 static int
68 saslc__mech_crammd5_cont(saslc_sess_t *sess, const void *in, size_t inlen,
69     void **out, size_t *outlen)
70 {
71 	const char *authid, *passwd;
72 	char *digest, *name;
73 	int len;
74 
75 	/* server is doing first step, but some clients may call this function
76 	 * before getting data from server */
77 	if (inlen == 0) {
78 		*out = NULL;
79 		*outlen = 0;
80 		return MECH_STEP;
81 	}
82 
83 	if ((authid = saslc_sess_getprop(sess, SASLC_CRAM_MD5_AUTHID))
84 	    == NULL) {
85 		saslc__error_set(ERR(sess), ERROR_MECH,
86 		    "authid is required for an authentication");
87 		return MECH_ERROR;
88 	}
89 
90 	if ((passwd = saslc_sess_getprop(sess, SASLC_CRAM_MD5_PASSWORD))
91 	    == NULL) {
92 		saslc__error_set(ERR(sess), ERROR_MECH,
93 		    "passwd is required for an authentication");
94 		return MECH_ERROR;
95 	}
96 
97 
98 	digest = saslc__crypto_hmac_md5((const unsigned char *)passwd,
99 	    strlen(passwd), in, inlen);
100 
101 	if ((len = asprintf(&name, "%s %s", authid, digest)) == -1) {
102 		free(digest);
103 		saslc__error_set_errno(ERR(sess), ERROR_NOMEM);
104 		return MECH_ERROR;
105 	}
106 	*out = name;
107 	*outlen = len + 1;
108 
109 	free(digest);
110 
111 	return MECH_OK;
112 }
113 
114 /* mechanism definition */
115 const saslc__mech_t saslc__mech_crammd5 = {
116 	"CRAM-MD5", /* name */
117 	FLAG_DICTIONARY, /* flags */
118 	saslc__mech_generic_create, /* create */
119 	saslc__mech_crammd5_cont, /* step */
120 	NULL, /* encode */
121 	NULL, /* decode */
122 	saslc__mech_generic_destroy /* destroy */
123 };
124