| 1 | /* SASL server API implementation |
| 2 | * Rob Siemborski |
| 3 | * Tim Martin |
| 4 | * $Id: checkpw.c,v 1.49 2002/03/07 19:14:04 ken3 Exp $ |
| 5 | */ |
| 6 | /* |
| 7 | * Copyright (c) 2001 Carnegie Mellon University. All rights reserved. |
| 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 | * |
| 13 | * 1. Redistributions of source code must retain the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer. |
| 15 | * |
| 16 | * 2. Redistributions in binary form must reproduce the above copyright |
| 17 | * notice, this list of conditions and the following disclaimer in |
| 18 | * the documentation and/or other materials provided with the |
| 19 | * distribution. |
| 20 | * |
| 21 | * 3. The name "Carnegie Mellon University" must not be used to |
| 22 | * endorse or promote products derived from this software without |
| 23 | * prior written permission. For permission or any other legal |
| 24 | * details, please contact |
| 25 | * Office of Technology Transfer |
| 26 | * Carnegie Mellon University |
| 27 | * 5000 Forbes Avenue |
| 28 | * Pittsburgh, PA 15213-3890 |
| 29 | * (412) 268-4387, fax: (412) 268-7395 |
| 30 | * tech-transfer@andrew.cmu.edu |
| 31 | * |
| 32 | * 4. Redistributions of any form whatsoever must retain the following |
| 33 | * acknowledgment: |
| 34 | * "This product includes software developed by Computing Services |
| 35 | * at Carnegie Mellon University (http://www.cmu.edu/computing/)." |
| 36 | * |
| 37 | * CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO |
| 38 | * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY |
| 39 | * AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE |
| 40 | * FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
| 41 | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN |
| 42 | * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING |
| 43 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
| 44 | */ |
| 45 | |
| 46 | /* |
| 47 | * Taken from Cyrus-SASL library and adapted by Alexander S. Sabourenkov |
| 48 | * Oct 2001 - Apr 2002: Slightly modified by Philip Hazel. |
| 49 | * Aug 2003: new code for saslauthd from Alexander S. Sabourenkov incorporated |
| 50 | * by Philip Hazel (minor mods to avoid compiler warnings) |
| 51 | * Oct 2006: (PH) removed redundant tests on "reply" being NULL - some were |
| 52 | * missing, and confused someone who was using this code for some |
| 53 | * other purpose. Here in Exim, "reply" is never NULL. |
| 54 | * |
| 55 | * screwdriver@lxnt.info |
| 56 | * |
| 57 | */ |
| 58 | |
| 59 | /* Originally this module supported only the pwcheck daemon, which is where its |
| 60 | name comes from. Nowadays it supports saslauthd as well; pwcheck is in fact |
| 61 | deprecated. The definitions of CYRUS_PWCHECK_SOCKET and CYRUS_SASLAUTHD_SOCKET |
| 62 | determine whether the facilities are actually supported or not. */ |
| 63 | |
| 64 | |
| 65 | #include "../exim.h" |
| 66 | #include "pwcheck.h" |
| 67 | |
| 68 | |
| 69 | #if defined(CYRUS_PWCHECK_SOCKET) || defined(CYRUS_SASLAUTHD_SOCKET) |
| 70 | |
| 71 | #include <sys/uio.h> |
| 72 | |
| 73 | static int retry_read(int, void *, unsigned ); |
| 74 | static int retry_writev(int, struct iovec *, int ); |
| 75 | static int read_string(int, uschar **); |
| 76 | static int write_string(int, const uschar *, int); |
| 77 | |
| 78 | #endif |
| 79 | |
| 80 | |
| 81 | /* A dummy function that always fails if pwcheck support is not |
| 82 | wanted. */ |
| 83 | |
| 84 | #ifndef CYRUS_PWCHECK_SOCKET |
| 85 | int pwcheck_verify_password(const char *userid, |
| 86 | const char *passwd, |
| 87 | const char **reply) |
| 88 | { |
| 89 | userid = userid; /* Keep picky compilers happy */ |
| 90 | passwd = passwd; |
| 91 | *reply = "pwcheck support is not included in this Exim binary"; |
| 92 | return PWCHECK_FAIL; |
| 93 | } |
| 94 | |
| 95 | |
| 96 | /* This is the real function */ |
| 97 | |
| 98 | #else |
| 99 | |
| 100 | /* taken from cyrus-sasl file checkpw.c */ |
| 101 | /* pwcheck daemon-authenticated login */ |
| 102 | int pwcheck_verify_password(const char *userid, |
| 103 | const char *passwd, |
| 104 | const char **reply) |
| 105 | { |
| 106 | int s, start, r, n; |
| 107 | struct sockaddr_un srvaddr; |
| 108 | struct iovec iov[2]; |
| 109 | static char response[1024]; |
| 110 | |
| 111 | *reply = NULL; |
| 112 | |
| 113 | s = socket(AF_UNIX, SOCK_STREAM, 0); |
| 114 | if (s == -1) { return PWCHECK_FAIL; } |
| 115 | |
| 116 | memset((char *)&srvaddr, 0, sizeof(srvaddr)); |
| 117 | srvaddr.sun_family = AF_UNIX; |
| 118 | strncpy(srvaddr.sun_path, CYRUS_PWCHECK_SOCKET, sizeof(srvaddr.sun_path)); |
| 119 | r = connect(s, (struct sockaddr *)&srvaddr, sizeof(srvaddr)); |
| 120 | if (r == -1) { |
| 121 | DEBUG(D_auth) |
| 122 | debug_printf("Cannot connect to pwcheck daemon (at '%s')\n",CYRUS_PWCHECK_SOCKET); |
| 123 | *reply = "cannot connect to pwcheck daemon"; |
| 124 | return PWCHECK_FAIL; |
| 125 | } |
| 126 | |
| 127 | iov[0].iov_base = (char *)userid; |
| 128 | iov[0].iov_len = strlen(userid)+1; |
| 129 | iov[1].iov_base = (char *)passwd; |
| 130 | iov[1].iov_len = strlen(passwd)+1; |
| 131 | |
| 132 | retry_writev(s, iov, 2); |
| 133 | |
| 134 | start = 0; |
| 135 | while (start < sizeof(response) - 1) { |
| 136 | n = read(s, response+start, sizeof(response) - 1 - start); |
| 137 | if (n < 1) break; |
| 138 | start += n; |
| 139 | } |
| 140 | |
| 141 | (void)close(s); |
| 142 | |
| 143 | if (start > 1 && !strncmp(response, "OK", 2)) { |
| 144 | return PWCHECK_OK; |
| 145 | } |
| 146 | |
| 147 | response[start] = '\0'; |
| 148 | *reply = response; |
| 149 | return PWCHECK_NO; |
| 150 | } |
| 151 | |
| 152 | #endif |
| 153 | |
| 154 | |
| 155 | |
| 156 | /* A dummy function that always fails if saslauthd support is not |
| 157 | wanted. */ |
| 158 | |
| 159 | #ifndef CYRUS_SASLAUTHD_SOCKET |
| 160 | int saslauthd_verify_password(const uschar *userid, |
| 161 | const uschar *passwd, |
| 162 | const uschar *service, |
| 163 | const uschar *realm, |
| 164 | const uschar **reply) |
| 165 | { |
| 166 | userid = userid; /* Keep picky compilers happy */ |
| 167 | passwd = passwd; |
| 168 | service = service; |
| 169 | realm = realm; |
| 170 | *reply = US"saslauthd support is not included in this Exim binary"; |
| 171 | return PWCHECK_FAIL; |
| 172 | } |
| 173 | |
| 174 | |
| 175 | /* This is the real function */ |
| 176 | |
| 177 | #else |
| 178 | /* written from scratch */ |
| 179 | /* saslauthd daemon-authenticated login */ |
| 180 | |
| 181 | int saslauthd_verify_password(const uschar *userid, |
| 182 | const uschar *password, |
| 183 | const uschar *service, |
| 184 | const uschar *realm, |
| 185 | const uschar **reply) |
| 186 | { |
| 187 | uschar *daemon_reply = NULL; |
| 188 | int s, r; |
| 189 | struct sockaddr_un srvaddr; |
| 190 | |
| 191 | DEBUG(D_auth) |
| 192 | debug_printf("saslauthd userid='%s' servicename='%s'" |
| 193 | " realm='%s'\n", userid, service, realm ); |
| 194 | |
| 195 | *reply = NULL; |
| 196 | |
| 197 | s = socket(AF_UNIX, SOCK_STREAM, 0); |
| 198 | if (s == -1) { |
| 199 | *reply = CUstrerror(errno); |
| 200 | return PWCHECK_FAIL; |
| 201 | } |
| 202 | |
| 203 | memset((char *)&srvaddr, 0, sizeof(srvaddr)); |
| 204 | srvaddr.sun_family = AF_UNIX; |
| 205 | strncpy(srvaddr.sun_path, CYRUS_SASLAUTHD_SOCKET, |
| 206 | sizeof(srvaddr.sun_path)); |
| 207 | r = connect(s, (struct sockaddr *)&srvaddr, sizeof(srvaddr)); |
| 208 | if (r == -1) { |
| 209 | DEBUG(D_auth) |
| 210 | debug_printf("Cannot connect to saslauthd daemon (at '%s'): %s\n", |
| 211 | CYRUS_SASLAUTHD_SOCKET, strerror(errno)); |
| 212 | *reply = string_sprintf("cannot connect to saslauthd daemon at " |
| 213 | "%s: %s", CYRUS_SASLAUTHD_SOCKET, |
| 214 | strerror(errno)); |
| 215 | return PWCHECK_FAIL; |
| 216 | } |
| 217 | |
| 218 | if ( write_string(s, userid, Ustrlen(userid)) < 0) { |
| 219 | DEBUG(D_auth) |
| 220 | debug_printf("Failed to send userid to saslauthd daemon \n"); |
| 221 | (void)close(s); |
| 222 | return PWCHECK_FAIL; |
| 223 | } |
| 224 | |
| 225 | if ( write_string(s, password, Ustrlen(password)) < 0) { |
| 226 | DEBUG(D_auth) |
| 227 | debug_printf("Failed to send password to saslauthd daemon \n"); |
| 228 | (void)close(s); |
| 229 | return PWCHECK_FAIL; |
| 230 | } |
| 231 | |
| 232 | memset((void *)password, 0, Ustrlen(password)); |
| 233 | |
| 234 | if ( write_string(s, service, Ustrlen(service)) < 0) { |
| 235 | DEBUG(D_auth) |
| 236 | debug_printf("Failed to send service name to saslauthd daemon \n"); |
| 237 | (void)close(s); |
| 238 | return PWCHECK_FAIL; |
| 239 | } |
| 240 | |
| 241 | if ( write_string(s, realm, Ustrlen(realm)) < 0) { |
| 242 | DEBUG(D_auth) |
| 243 | debug_printf("Failed to send realm to saslauthd daemon \n"); |
| 244 | (void)close(s); |
| 245 | return PWCHECK_FAIL; |
| 246 | } |
| 247 | |
| 248 | if ( read_string(s, &daemon_reply ) < 2) { |
| 249 | DEBUG(D_auth) |
| 250 | debug_printf("Corrupted answer '%s' received. \n", daemon_reply); |
| 251 | (void)close(s); |
| 252 | return PWCHECK_FAIL; |
| 253 | } |
| 254 | |
| 255 | (void)close(s); |
| 256 | |
| 257 | DEBUG(D_auth) |
| 258 | debug_printf("Answer '%s' received. \n", daemon_reply); |
| 259 | |
| 260 | *reply = daemon_reply; |
| 261 | |
| 262 | if ( (daemon_reply[0] == 'O') && (daemon_reply[1] == 'K') ) |
| 263 | return PWCHECK_OK; |
| 264 | |
| 265 | if ( (daemon_reply[0] == 'N') && (daemon_reply[1] == 'O') ) |
| 266 | return PWCHECK_NO; |
| 267 | |
| 268 | return PWCHECK_FAIL; |
| 269 | } |
| 270 | |
| 271 | #endif |
| 272 | |
| 273 | |
| 274 | /* helper functions */ |
| 275 | #if defined(CYRUS_PWCHECK_SOCKET) || defined(CYRUS_SASLAUTHD_SOCKET) |
| 276 | |
| 277 | #define MAX_REQ_LEN 1024 |
| 278 | |
| 279 | /* written from scratch */ |
| 280 | |
| 281 | /* FUNCTION: read_string */ |
| 282 | |
| 283 | /* SYNOPSIS |
| 284 | * read a sasld-style counted string into |
| 285 | * store-allocated buffer, set pointer to the buffer, |
| 286 | * return number of bytes read or -1 on failure. |
| 287 | * END SYNOPSIS */ |
| 288 | |
| 289 | static int read_string(int fd, uschar **retval) { |
| 290 | unsigned short count; |
| 291 | int rc; |
| 292 | |
| 293 | rc = (retry_read(fd, &count, sizeof(count)) < (int) sizeof(count)); |
| 294 | if (!rc) { |
| 295 | count = ntohs(count); |
| 296 | if (count > MAX_REQ_LEN) { |
| 297 | return -1; |
| 298 | } else { |
| 299 | *retval = store_get(count + 1); |
| 300 | rc = (retry_read(fd, *retval, count) < (int) count); |
| 301 | (*retval)[count] = '\0'; |
| 302 | return count; |
| 303 | } |
| 304 | } |
| 305 | return -1; |
| 306 | } |
| 307 | |
| 308 | |
| 309 | /* FUNCTION: write_string */ |
| 310 | |
| 311 | /* SYNOPSIS |
| 312 | * write a sasld-style counted string into given fd |
| 313 | * written bytes on success, -1 on failure. |
| 314 | * END SYNOPSIS */ |
| 315 | |
| 316 | static int write_string(int fd, const uschar *string, int len) { |
| 317 | unsigned short count; |
| 318 | int rc; |
| 319 | struct iovec iov[2]; |
| 320 | |
| 321 | count = htons(len); |
| 322 | |
| 323 | iov[0].iov_base = (void *) &count; |
| 324 | iov[0].iov_len = sizeof(count); |
| 325 | iov[1].iov_base = (void *) string; |
| 326 | iov[1].iov_len = len; |
| 327 | |
| 328 | rc = retry_writev(fd, iov, 2); |
| 329 | |
| 330 | return rc; |
| 331 | } |
| 332 | |
| 333 | |
| 334 | /* taken from cyrus-sasl file saslauthd/saslauthd-unix.c */ |
| 335 | |
| 336 | /* FUNCTION: retry_read */ |
| 337 | |
| 338 | /* SYNOPSIS |
| 339 | * Keep calling the read() system call with 'fd', 'buf', and 'nbyte' |
| 340 | * until all the data is read in or an error occurs. |
| 341 | * END SYNOPSIS */ |
| 342 | static int retry_read(int fd, void *inbuf, unsigned nbyte) |
| 343 | { |
| 344 | int n; |
| 345 | int nread = 0; |
| 346 | char *buf = (char *)inbuf; |
| 347 | |
| 348 | if (nbyte == 0) return 0; |
| 349 | |
| 350 | for (;;) { |
| 351 | n = read(fd, buf, nbyte); |
| 352 | if (n == 0) { |
| 353 | /* end of file */ |
| 354 | return -1; |
| 355 | } |
| 356 | if (n == -1) { |
| 357 | if (errno == EINTR) continue; |
| 358 | return -1; |
| 359 | } |
| 360 | |
| 361 | nread += n; |
| 362 | |
| 363 | if (n >= (int) nbyte) return nread; |
| 364 | |
| 365 | buf += n; |
| 366 | nbyte -= n; |
| 367 | } |
| 368 | } |
| 369 | |
| 370 | /* END FUNCTION: retry_read */ |
| 371 | |
| 372 | /* FUNCTION: retry_writev */ |
| 373 | |
| 374 | /* SYNOPSIS |
| 375 | * Keep calling the writev() system call with 'fd', 'iov', and 'iovcnt' |
| 376 | * until all the data is written out or an error occurs. |
| 377 | * END SYNOPSIS */ |
| 378 | |
| 379 | static int /* R: bytes written, or -1 on error */ |
| 380 | retry_writev ( |
| 381 | /* PARAMETERS */ |
| 382 | int fd, /* I: fd to write on */ |
| 383 | struct iovec *iov, /* U: iovec array base |
| 384 | * modified as data written */ |
| 385 | int iovcnt /* I: number of iovec entries */ |
| 386 | /* END PARAMETERS */ |
| 387 | ) |
| 388 | { |
| 389 | /* VARIABLES */ |
| 390 | int n; /* return value from writev() */ |
| 391 | int i; /* loop counter */ |
| 392 | int written; /* bytes written so far */ |
| 393 | static int iov_max; /* max number of iovec entries */ |
| 394 | /* END VARIABLES */ |
| 395 | |
| 396 | /* initialization */ |
| 397 | #ifdef MAXIOV |
| 398 | iov_max = MAXIOV; |
| 399 | #else /* ! MAXIOV */ |
| 400 | # ifdef IOV_MAX |
| 401 | iov_max = IOV_MAX; |
| 402 | # else /* ! IOV_MAX */ |
| 403 | iov_max = 8192; |
| 404 | # endif /* ! IOV_MAX */ |
| 405 | #endif /* ! MAXIOV */ |
| 406 | written = 0; |
| 407 | |
| 408 | for (;;) { |
| 409 | |
| 410 | while (iovcnt && iov[0].iov_len == 0) { |
| 411 | iov++; |
| 412 | iovcnt--; |
| 413 | } |
| 414 | |
| 415 | if (!iovcnt) { |
| 416 | return written; |
| 417 | } |
| 418 | |
| 419 | n = writev(fd, iov, iovcnt > iov_max ? iov_max : iovcnt); |
| 420 | if (n == -1) { |
| 421 | if (errno == EINVAL && iov_max > 10) { |
| 422 | iov_max /= 2; |
| 423 | continue; |
| 424 | } |
| 425 | if (errno == EINTR) { |
| 426 | continue; |
| 427 | } |
| 428 | return -1; |
| 429 | } else { |
| 430 | written += n; |
| 431 | } |
| 432 | |
| 433 | for (i = 0; i < iovcnt; i++) { |
| 434 | if (iov[i].iov_len > (unsigned) n) { |
| 435 | iov[i].iov_base = (char *)iov[i].iov_base + n; |
| 436 | iov[i].iov_len -= n; |
| 437 | break; |
| 438 | } |
| 439 | n -= iov[i].iov_len; |
| 440 | iov[i].iov_len = 0; |
| 441 | } |
| 442 | |
| 443 | if (i == iovcnt) { |
| 444 | return written; |
| 445 | } |
| 446 | } |
| 447 | /* NOTREACHED */ |
| 448 | } |
| 449 | |
| 450 | /* END FUNCTION: retry_writev */ |
| 451 | #endif |
| 452 | |
| 453 | /* End of auths/pwcheck.c */ |