2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
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
16 * the documentation and/or other materials provided with the
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
29 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
30 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
31 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
32 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 #include <openssl/x509.h>
37 #include <openssl/md5.h>
38 #include <openssl/ssl.h>
39 #include <openssl/err.h>
40 #include <openssl/pem.h>
41 #include <openssl/rand.h>
49 init_cert_file(SSL_CTX *ctx, const char *path)
53 /* Load certificate into ctx */
54 error = SSL_CTX_use_certificate_chain_file(ctx, path);
56 syslog(LOG_ERR, "SSL: Cannot load certificate `%s': %s", path, ssl_errstr());
60 /* Add private key to ctx */
61 error = SSL_CTX_use_PrivateKey_file(ctx, path, SSL_FILETYPE_PEM);
63 syslog(LOG_ERR, "SSL: Cannot load private key `%s': %s", path, ssl_errstr());
68 * Check the consistency of a private key with the corresponding
71 error = SSL_CTX_check_private_key(ctx);
73 syslog(LOG_ERR, "SSL: Cannot check private key: %s", ssl_errstr());
81 smtp_init_crypto(int fd, int feature)
84 #if (OPENSSL_VERSION_NUMBER >= 0x00909000L)
85 const SSL_METHOD *meth = NULL;
87 SSL_METHOD *meth = NULL;
92 /* XXX clean up on error/close */
93 /* Init SSL library */
95 SSL_load_error_strings();
97 // Allow any possible version
98 #if (OPENSSL_VERSION_NUMBER >= 0x10100000L)
99 meth = TLS_client_method();
101 meth = SSLv23_client_method();
104 ctx = SSL_CTX_new(meth);
106 syslog(LOG_WARNING, "remote delivery deferred: SSL init failed: %s", ssl_errstr());
110 /* User supplied a certificate */
111 if (config.certfile != NULL) {
112 error = init_cert_file(ctx, config.certfile);
114 syslog(LOG_WARNING, "remote delivery deferred");
120 * If the user wants STARTTLS, we have to send EHLO here
122 if (((feature & SECURETRANS) != 0) &&
123 (feature & STARTTLS) != 0) {
124 /* TLS init phase, disable SSL_write */
125 config.features |= NOSSL;
127 send_remote_command(fd, "EHLO %s", hostname());
128 if (read_remote(fd, 0, NULL) == 2) {
129 send_remote_command(fd, "STARTTLS");
130 if (read_remote(fd, 0, NULL) != 2) {
131 if ((feature & TLS_OPP) == 0) {
132 syslog(LOG_ERR, "remote delivery deferred: STARTTLS not available: %s", neterr);
135 syslog(LOG_INFO, "in opportunistic TLS mode, STARTTLS not available: %s", neterr);
140 /* End of TLS init phase, enable SSL_write/read */
141 config.features &= ~NOSSL;
144 config.ssl = SSL_new(ctx);
145 if (config.ssl == NULL) {
146 syslog(LOG_NOTICE, "remote delivery deferred: SSL struct creation failed: %s",
151 /* Set ssl to work in client mode */
152 SSL_set_connect_state(config.ssl);
154 /* Set fd for SSL in/output */
155 error = SSL_set_fd(config.ssl, fd);
157 syslog(LOG_NOTICE, "remote delivery deferred: SSL set fd failed: %s",
162 /* Open SSL connection */
163 error = SSL_connect(config.ssl);
165 syslog(LOG_ERR, "remote delivery deferred: SSL handshake failed fatally: %s",
170 /* Get peer certificate */
171 cert = SSL_get_peer_certificate(config.ssl);
173 syslog(LOG_WARNING, "remote delivery deferred: Peer did not provide certificate: %s",
182 * hmac_md5() taken out of RFC 2104. This RFC was written by H. Krawczyk,
183 * M. Bellare and R. Canetti.
185 * text pointer to data stream
186 * text_len length of data stream
187 * key pointer to authentication key
188 * key_len length of authentication key
189 * digest caller digest to be filled int
192 hmac_md5(unsigned char *text, int text_len, unsigned char *key, int key_len,
193 unsigned char* digest)
196 unsigned char k_ipad[65]; /* inner padding -
199 unsigned char k_opad[65]; /* outer padding -
202 unsigned char tk[16];
204 /* if key is longer than 64 bytes reset it to key=MD5(key) */
210 MD5_Update(&tctx, key, key_len);
211 MD5_Final(tk, &tctx);
218 * the HMAC_MD5 transform looks like:
220 * MD5(K XOR opad, MD5(K XOR ipad, text))
222 * where K is an n byte key
223 * ipad is the byte 0x36 repeated 64 times
225 * opad is the byte 0x5c repeated 64 times
226 * and text is the data being protected
229 /* start out by storing key in pads */
230 bzero( k_ipad, sizeof k_ipad);
231 bzero( k_opad, sizeof k_opad);
232 bcopy( key, k_ipad, key_len);
233 bcopy( key, k_opad, key_len);
235 /* XOR key with ipad and opad values */
236 for (i=0; i<64; i++) {
243 MD5_Init(&context); /* init context for 1st
245 MD5_Update(&context, k_ipad, 64); /* start with inner pad */
246 MD5_Update(&context, text, text_len); /* then text of datagram */
247 MD5_Final(digest, &context); /* finish up 1st pass */
251 MD5_Init(&context); /* init context for 2nd
253 MD5_Update(&context, k_opad, 64); /* start with outer pad */
254 MD5_Update(&context, digest, 16); /* then results of 1st
256 MD5_Final(digest, &context); /* finish up 2nd pass */
260 * CRAM-MD5 authentication
263 smtp_auth_md5(int fd, char *login, char *password)
265 unsigned char digest[BUF_SIZE];
266 char buffer[BUF_SIZE], ascii_digest[33];
269 static char hextab[] = "0123456789abcdef";
271 temp = calloc(BUF_SIZE, 1);
272 memset(buffer, 0, sizeof(buffer));
273 memset(digest, 0, sizeof(digest));
274 memset(ascii_digest, 0, sizeof(ascii_digest));
276 /* Send AUTH command according to RFC 2554 */
277 send_remote_command(fd, "AUTH CRAM-MD5");
278 if (read_remote(fd, sizeof(buffer), buffer) != 3) {
279 syslog(LOG_DEBUG, "smarthost authentication:"
280 " AUTH cram-md5 not available: %s", neterr);
281 /* if cram-md5 is not available */
286 /* skip 3 char status + 1 char space */
287 base64_decode(buffer + 4, temp);
288 hmac_md5((unsigned char *)temp, strlen(temp),
289 (unsigned char *)password, strlen(password), digest);
292 ascii_digest[32] = 0;
293 for (i = 0; i < 16; i++) {
294 ascii_digest[2*i] = hextab[digest[i] >> 4];
295 ascii_digest[2*i+1] = hextab[digest[i] & 15];
299 snprintf(buffer, BUF_SIZE, "%s %s", login, ascii_digest);
302 len = base64_encode(buffer, strlen(buffer), &temp);
304 syslog(LOG_ERR, "can not encode auth reply: %m");
309 send_remote_command(fd, "%s", temp);
311 if (read_remote(fd, 0, NULL) != 2) {
312 syslog(LOG_WARNING, "remote delivery deferred:"
313 " AUTH cram-md5 failed: %s", neterr);