1 /* $Id: mech_crammd5.c,v 1.2 2011/01/29 23:35:31 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; 73 int len; 74 75 authid = saslc_sess_getprop(sess, SASLC_CRAM_MD5_AUTHID); 76 if (authid == NULL) { 77 saslc__error_set(ERR(sess), ERROR_MECH, 78 "authid is required for an authentication"); 79 return MECH_ERROR; 80 } 81 82 passwd = saslc_sess_getprop(sess, SASLC_CRAM_MD5_PASSWORD); 83 if (passwd == NULL) { 84 saslc__error_set(ERR(sess), ERROR_MECH, 85 "passwd is required for an authentication"); 86 return MECH_ERROR; 87 } 88 89 /* server is doing first step, but some clients may call this function 90 * before getting data from server */ 91 if (inlen == 0) { 92 *out = NULL; 93 *outlen = 0; 94 return MECH_STEP; 95 } 96 97 digest = saslc__crypto_hmac_md5((const unsigned char *)passwd, 98 strlen(passwd), in, inlen); 99 100 if (digest == NULL) { 101 saslc__error_set_errno(ERR(sess), ERROR_NOMEM); 102 return MECH_ERROR; 103 } 104 105 len = asprintf((char **)out, "%s %s", authid, digest); 106 107 /* no longer need to keep the digest */ 108 free(digest); 109 110 if (len == -1) { 111 saslc__error_set_errno(ERR(sess), ERROR_NOMEM); 112 return MECH_ERROR; 113 } 114 115 *outlen = (size_t)len + 1; 116 117 return MECH_OK; 118 } 119 120 /* mechanism definition */ 121 const saslc__mech_t saslc__mech_crammd5 = { 122 "CRAM-MD5", /* name */ 123 saslc__mech_generic_create, /* create */ 124 saslc__mech_crammd5_cont, /* step */ 125 saslc__mech_generic_encode, /* encode */ 126 saslc__mech_generic_decode, /* decode */ 127 saslc__mech_generic_destroy /* destroy */ 128 }; 129