dma(8): Upgrade to v0.7.
[dragonfly.git] / libexec / dma / crypto.c
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1/*
2 * Copyright (c) 2008 The DragonFly Project. All rights reserved.
3 *
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthias Schmidt <matthias@dragonflybsd.org>, University of Marburg,
6 * Germany.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
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
17 * distribution.
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.
21 *
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
33 * SUCH DAMAGE.
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34 */
35
f67beddd 36#include <openssl/x509.h>
7b68d8ae 37#include <openssl/md5.h>
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38#include <openssl/ssl.h>
39#include <openssl/err.h>
40#include <openssl/pem.h>
41#include <openssl/rand.h>
42
43#include <syslog.h>
44
45#include "dma.h"
46
f67beddd 47static int
405f48ee 48init_cert_file(SSL_CTX *ctx, const char *path)
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49{
50 int error;
51
52 /* Load certificate into ctx */
53 error = SSL_CTX_use_certificate_chain_file(ctx, path);
54 if (error < 1) {
405f48ee 55 syslog(LOG_ERR, "SSL: Cannot load certificate `%s': %s", path, ssl_errstr());
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56 return (-1);
57 }
58
59 /* Add private key to ctx */
60 error = SSL_CTX_use_PrivateKey_file(ctx, path, SSL_FILETYPE_PEM);
61 if (error < 1) {
405f48ee 62 syslog(LOG_ERR, "SSL: Cannot load private key `%s': %s", path, ssl_errstr());
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63 return (-1);
64 }
65
66 /*
67 * Check the consistency of a private key with the corresponding
68 * certificate
69 */
70 error = SSL_CTX_check_private_key(ctx);
71 if (error < 1) {
405f48ee 72 syslog(LOG_ERR, "SSL: Cannot check private key: %s", ssl_errstr());
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73 return (-1);
74 }
75
76 return (0);
77}
78
79int
405f48ee 80smtp_init_crypto(int fd, int feature)
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81{
82 SSL_CTX *ctx = NULL;
01185282 83 const SSL_METHOD *meth = NULL;
f67beddd 84 X509 *cert;
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85 int error;
86
ea921663 87 /* XXX clean up on error/close */
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88 /* Init SSL library */
89 SSL_library_init();
e2c88018 90 SSL_load_error_strings();
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91
92 meth = TLSv1_client_method();
93
94 ctx = SSL_CTX_new(meth);
95 if (ctx == NULL) {
405f48ee 96 syslog(LOG_WARNING, "remote delivery deferred: SSL init failed: %s", ssl_errstr());
e2c88018 97 return (1);
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98 }
99
100 /* User supplied a certificate */
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101 if (config.certfile != NULL) {
102 error = init_cert_file(ctx, config.certfile);
e2c88018 103 if (error) {
405f48ee 104 syslog(LOG_WARNING, "remote delivery deferred");
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105 return (1);
106 }
107 }
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108
109 /*
110 * If the user wants STARTTLS, we have to send EHLO here
111 */
112 if (((feature & SECURETRANS) != 0) &&
113 (feature & STARTTLS) != 0) {
114 /* TLS init phase, disable SSL_write */
ca259d14 115 config.features |= NOSSL;
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116
117 send_remote_command(fd, "EHLO %s", hostname());
7b68d8ae 118 if (read_remote(fd, 0, NULL) == 2) {
f67beddd 119 send_remote_command(fd, "STARTTLS");
7b68d8ae 120 if (read_remote(fd, 0, NULL) != 2) {
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121 if ((feature & TLS_OPP) == 0) {
122 syslog(LOG_ERR, "remote delivery deferred: STARTTLS not available: %s", neterr);
123 return (1);
124 } else {
125 syslog(LOG_INFO, "in opportunistic TLS mode, STARTTLS not available: %s", neterr);
126 return (0);
127 }
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128 }
129 }
130 /* End of TLS init phase, enable SSL_write/read */
ca259d14 131 config.features &= ~NOSSL;
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132 }
133
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134 config.ssl = SSL_new(ctx);
135 if (config.ssl == NULL) {
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136 syslog(LOG_NOTICE, "remote delivery deferred: SSL struct creation failed: %s",
137 ssl_errstr());
e2c88018 138 return (1);
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139 }
140
141 /* Set ssl to work in client mode */
ca259d14 142 SSL_set_connect_state(config.ssl);
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143
144 /* Set fd for SSL in/output */
ca259d14 145 error = SSL_set_fd(config.ssl, fd);
f67beddd 146 if (error == 0) {
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147 syslog(LOG_NOTICE, "remote delivery deferred: SSL set fd failed: %s",
148 ssl_errstr());
e2c88018 149 return (1);
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150 }
151
152 /* Open SSL connection */
ca259d14 153 error = SSL_connect(config.ssl);
f67beddd 154 if (error < 0) {
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155 syslog(LOG_ERR, "remote delivery deferred: SSL handshake failed fatally: %s",
156 ssl_errstr());
e2c88018 157 return (1);
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158 }
159
160 /* Get peer certificate */
ca259d14 161 cert = SSL_get_peer_certificate(config.ssl);
f67beddd 162 if (cert == NULL) {
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163 syslog(LOG_WARNING, "remote delivery deferred: Peer did not provide certificate: %s",
164 ssl_errstr());
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165 }
166 X509_free(cert);
167
168 return (0);
169}
170
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171/*
172 * hmac_md5() taken out of RFC 2104. This RFC was written by H. Krawczyk,
173 * M. Bellare and R. Canetti.
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174 *
175 * text pointer to data stream
176 * text_len length of data stream
177 * key pointer to authentication key
178 * key_len length of authentication key
179 * digest caller digest to be filled int
180 */
7b68d8ae 181void
bc7baf1d 182hmac_md5(unsigned char *text, int text_len, unsigned char *key, int key_len,
c8b07ee5 183 unsigned char* digest)
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184{
185 MD5_CTX context;
186 unsigned char k_ipad[65]; /* inner padding -
187 * key XORd with ipad
188 */
189 unsigned char k_opad[65]; /* outer padding -
190 * key XORd with opad
191 */
192 unsigned char tk[16];
193 int i;
194 /* if key is longer than 64 bytes reset it to key=MD5(key) */
195 if (key_len > 64) {
196
197 MD5_CTX tctx;
198
199 MD5_Init(&tctx);
200 MD5_Update(&tctx, key, key_len);
201 MD5_Final(tk, &tctx);
202
203 key = tk;
204 key_len = 16;
205 }
206
207 /*
208 * the HMAC_MD5 transform looks like:
209 *
210 * MD5(K XOR opad, MD5(K XOR ipad, text))
211 *
212 * where K is an n byte key
213 * ipad is the byte 0x36 repeated 64 times
214 *
215 * opad is the byte 0x5c repeated 64 times
216 * and text is the data being protected
217 */
218
219 /* start out by storing key in pads */
220 bzero( k_ipad, sizeof k_ipad);
221 bzero( k_opad, sizeof k_opad);
222 bcopy( key, k_ipad, key_len);
223 bcopy( key, k_opad, key_len);
224
225 /* XOR key with ipad and opad values */
226 for (i=0; i<64; i++) {
227 k_ipad[i] ^= 0x36;
228 k_opad[i] ^= 0x5c;
229 }
230 /*
231 * perform inner MD5
232 */
233 MD5_Init(&context); /* init context for 1st
234 * pass */
235 MD5_Update(&context, k_ipad, 64); /* start with inner pad */
236 MD5_Update(&context, text, text_len); /* then text of datagram */
237 MD5_Final(digest, &context); /* finish up 1st pass */
238 /*
239 * perform outer MD5
240 */
241 MD5_Init(&context); /* init context for 2nd
242 * pass */
243 MD5_Update(&context, k_opad, 64); /* start with outer pad */
244 MD5_Update(&context, digest, 16); /* then results of 1st
245 * hash */
246 MD5_Final(digest, &context); /* finish up 2nd pass */
247}
248
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249/*
250 * CRAM-MD5 authentication
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251 */
252int
405f48ee 253smtp_auth_md5(int fd, char *login, char *password)
f67beddd 254{
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255 unsigned char digest[BUF_SIZE];
256 char buffer[BUF_SIZE], ascii_digest[33];
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257 char *temp;
258 int len, i;
259 static char hextab[] = "0123456789abcdef";
260
261 temp = calloc(BUF_SIZE, 1);
262 memset(buffer, 0, sizeof(buffer));
263 memset(digest, 0, sizeof(digest));
264 memset(ascii_digest, 0, sizeof(ascii_digest));
265
266 /* Send AUTH command according to RFC 2554 */
267 send_remote_command(fd, "AUTH CRAM-MD5");
268 if (read_remote(fd, sizeof(buffer), buffer) != 3) {
34599d02 269 syslog(LOG_DEBUG, "smarthost authentication:"
405f48ee 270 " AUTH cram-md5 not available: %s", neterr);
7b68d8ae 271 /* if cram-md5 is not available */
c8b07ee5 272 free(temp);
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273 return (-1);
274 }
275
276 /* skip 3 char status + 1 char space */
277 base64_decode(buffer + 4, temp);
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278 hmac_md5((unsigned char *)temp, strlen(temp),
279 (unsigned char *)password, strlen(password), digest);
5d7fe8bb 280 free(temp);
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281
282 ascii_digest[32] = 0;
283 for (i = 0; i < 16; i++) {
284 ascii_digest[2*i] = hextab[digest[i] >> 4];
285 ascii_digest[2*i+1] = hextab[digest[i] & 15];
286 }
287
288 /* prepare answer */
289 snprintf(buffer, BUF_SIZE, "%s %s", login, ascii_digest);
290
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291 /* encode answer */
292 len = base64_encode(buffer, strlen(buffer), &temp);
5d7fe8bb 293 if (len < 0) {
405f48ee 294 syslog(LOG_ERR, "can not encode auth reply: %m");
7b68d8ae 295 return (-1);
5d7fe8bb 296 }
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297
298 /* send answer */
299 send_remote_command(fd, "%s", temp);
5d7fe8bb 300 free(temp);
7b68d8ae 301 if (read_remote(fd, 0, NULL) != 2) {
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302 syslog(LOG_WARNING, "remote delivery deferred:"
303 " AUTH cram-md5 failed: %s", neterr);
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304 return (-2);
305 }
306
307 return (0);
f67beddd 308}