1 /*- 2 * Copyright 1998 Juniper Networks, Inc. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/lib/libradius/radlib.c 339270 2018-10-09 21:28:26Z gjb $ 27 */ 28 29 #include <sys/cdefs.h> 30 31 #include <sys/types.h> 32 #include <sys/socket.h> 33 #include <sys/time.h> 34 #include <netinet/in.h> 35 #include <arpa/inet.h> 36 #ifdef WITH_SSL 37 #include <openssl/hmac.h> 38 #include <openssl/md5.h> 39 #define MD5Init MD5_Init 40 #define MD5Update MD5_Update 41 #define MD5Final MD5_Final 42 #else 43 #define MD5_DIGEST_LENGTH 16 44 #include <md5.h> 45 #endif 46 47 #define MAX_FIELDS 7 48 49 /* We need the MPPE_KEY_LEN define */ 50 #ifdef WANT_NETGRAPH7 51 #include <netgraph7/mppc/ng_mppc.h> 52 #else 53 #include <netgraph/mppc/ng_mppc.h> 54 #endif 55 56 #include <errno.h> 57 #include <netdb.h> 58 #include <stdarg.h> 59 #include <stddef.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 #include <unistd.h> 64 65 #include "radlib_private.h" 66 67 static void clear_password(struct rad_handle *); 68 static void generr(struct rad_handle *, const char *, ...) 69 __printflike(2, 3); 70 static void insert_scrambled_password(struct rad_handle *, int); 71 static void insert_request_authenticator(struct rad_handle *, int); 72 static void insert_message_authenticator(struct rad_handle *, int); 73 static int is_valid_response(struct rad_handle *, int, 74 const struct sockaddr_in *); 75 static int put_password_attr(struct rad_handle *, int, 76 const void *, size_t); 77 static int put_raw_attr(struct rad_handle *, int, 78 const void *, size_t); 79 static int split(char *, const char *[], int, char *, size_t); 80 81 static void 82 clear_password(struct rad_handle *h) 83 { 84 if (h->pass_len != 0) { 85 memset(h->pass, 0, h->pass_len); 86 h->pass_len = 0; 87 } 88 h->pass_pos = 0; 89 } 90 91 static void 92 generr(struct rad_handle *h, const char *format, ...) 93 { 94 va_list ap; 95 96 va_start(ap, format); 97 vsnprintf(h->errmsg, ERRSIZE, format, ap); 98 va_end(ap); 99 } 100 101 static void 102 insert_scrambled_password(struct rad_handle *h, int srv) 103 { 104 MD5_CTX ctx; 105 unsigned char md5[MD5_DIGEST_LENGTH]; 106 const struct rad_server *srvp; 107 int padded_len; 108 int pos; 109 110 srvp = &h->servers[srv]; 111 padded_len = h->pass_len == 0 ? 16 : (h->pass_len+15) & ~0xf; 112 113 memcpy(md5, &h->out[POS_AUTH], LEN_AUTH); 114 for (pos = 0; pos < padded_len; pos += 16) { 115 int i; 116 117 /* Calculate the new scrambler */ 118 MD5Init(&ctx); 119 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 120 MD5Update(&ctx, md5, 16); 121 MD5Final(md5, &ctx); 122 123 /* 124 * Mix in the current chunk of the password, and copy 125 * the result into the right place in the request. Also 126 * modify the scrambler in place, since we will use this 127 * in calculating the scrambler for next time. 128 */ 129 for (i = 0; i < 16; i++) 130 h->out[h->pass_pos + pos + i] = 131 md5[i] ^= h->pass[pos + i]; 132 } 133 } 134 135 static void 136 insert_request_authenticator(struct rad_handle *h, int resp) 137 { 138 MD5_CTX ctx; 139 const struct rad_server *srvp; 140 141 srvp = &h->servers[h->srv]; 142 143 /* Create the request authenticator */ 144 MD5Init(&ctx); 145 MD5Update(&ctx, &h->out[POS_CODE], POS_AUTH - POS_CODE); 146 if (resp) 147 MD5Update(&ctx, &h->in[POS_AUTH], LEN_AUTH); 148 else 149 MD5Update(&ctx, &h->out[POS_AUTH], LEN_AUTH); 150 MD5Update(&ctx, &h->out[POS_ATTRS], h->out_len - POS_ATTRS); 151 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 152 MD5Final(&h->out[POS_AUTH], &ctx); 153 } 154 155 static void 156 insert_message_authenticator(struct rad_handle *h, int resp) 157 { 158 #ifdef WITH_SSL 159 u_char md[EVP_MAX_MD_SIZE]; 160 u_int md_len; 161 const struct rad_server *srvp; 162 HMAC_CTX *ctx; 163 srvp = &h->servers[h->srv]; 164 165 if (h->authentic_pos != 0) { 166 ctx = HMAC_CTX_new(); 167 HMAC_Init_ex(ctx, srvp->secret, strlen(srvp->secret), EVP_md5(), NULL); 168 HMAC_Update(ctx, &h->out[POS_CODE], POS_AUTH - POS_CODE); 169 if (resp) 170 HMAC_Update(ctx, &h->in[POS_AUTH], LEN_AUTH); 171 else 172 HMAC_Update(ctx, &h->out[POS_AUTH], LEN_AUTH); 173 HMAC_Update(ctx, &h->out[POS_ATTRS], 174 h->out_len - POS_ATTRS); 175 HMAC_Final(ctx, md, &md_len); 176 HMAC_CTX_free(ctx); 177 memcpy(&h->out[h->authentic_pos + 2], md, md_len); 178 } 179 #endif 180 } 181 182 /* 183 * Return true if the current response is valid for a request to the 184 * specified server. 185 */ 186 static int 187 is_valid_response(struct rad_handle *h, int srv, 188 const struct sockaddr_in *from) 189 { 190 MD5_CTX ctx; 191 unsigned char md5[MD5_DIGEST_LENGTH]; 192 const struct rad_server *srvp; 193 int len; 194 #ifdef WITH_SSL 195 HMAC_CTX *hctx; 196 u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE]; 197 u_int md_len; 198 int pos; 199 #endif 200 201 srvp = &h->servers[srv]; 202 203 /* Check the source address */ 204 if (from->sin_family != srvp->addr.sin_family || 205 from->sin_addr.s_addr != srvp->addr.sin_addr.s_addr || 206 from->sin_port != srvp->addr.sin_port) 207 return 0; 208 209 /* Check the message length */ 210 if (h->in_len < POS_ATTRS) 211 return 0; 212 len = h->in[POS_LENGTH] << 8 | h->in[POS_LENGTH+1]; 213 if (len > h->in_len) 214 return 0; 215 216 /* Check the response authenticator */ 217 MD5Init(&ctx); 218 MD5Update(&ctx, &h->in[POS_CODE], POS_AUTH - POS_CODE); 219 MD5Update(&ctx, &h->out[POS_AUTH], LEN_AUTH); 220 MD5Update(&ctx, &h->in[POS_ATTRS], len - POS_ATTRS); 221 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 222 MD5Final(md5, &ctx); 223 if (memcmp(&h->in[POS_AUTH], md5, sizeof md5) != 0) 224 return 0; 225 226 #ifdef WITH_SSL 227 /* 228 * For non accounting responses check the message authenticator, 229 * if any. 230 */ 231 if (h->in[POS_CODE] != RAD_ACCOUNTING_RESPONSE) { 232 233 memcpy(resp, h->in, MSGSIZE); 234 pos = POS_ATTRS; 235 236 /* Search and verify the Message-Authenticator */ 237 hctx = HMAC_CTX_new(); 238 while (pos < len - 2) { 239 240 if (h->in[pos] == RAD_MESSAGE_AUTHENTIC) { 241 /* zero fill the Message-Authenticator */ 242 memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH); 243 244 HMAC_Init_ex(hctx, srvp->secret, 245 strlen(srvp->secret), EVP_md5(), NULL); 246 HMAC_Update(hctx, &h->in[POS_CODE], 247 POS_AUTH - POS_CODE); 248 HMAC_Update(hctx, &h->out[POS_AUTH], 249 LEN_AUTH); 250 HMAC_Update(hctx, &resp[POS_ATTRS], 251 h->in_len - POS_ATTRS); 252 HMAC_Final(hctx, md, &md_len); 253 HMAC_CTX_reset(hctx); 254 if (memcmp(md, &h->in[pos + 2], 255 MD5_DIGEST_LENGTH) != 0) { 256 HMAC_CTX_free(hctx); 257 return 0; 258 } 259 break; 260 } 261 pos += h->in[pos + 1]; 262 } 263 HMAC_CTX_free(hctx); 264 } 265 #endif 266 return 1; 267 } 268 269 /* 270 * Return true if the current request is valid for the specified server. 271 */ 272 static int 273 is_valid_request(struct rad_handle *h) 274 { 275 MD5_CTX ctx; 276 unsigned char md5[MD5_DIGEST_LENGTH]; 277 const struct rad_server *srvp; 278 int len; 279 #ifdef WITH_SSL 280 HMAC_CTX *hctx; 281 u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE]; 282 u_int md_len; 283 int pos; 284 #endif 285 286 srvp = &h->servers[h->srv]; 287 288 /* Check the message length */ 289 if (h->in_len < POS_ATTRS) 290 return (0); 291 len = h->in[POS_LENGTH] << 8 | h->in[POS_LENGTH+1]; 292 if (len > h->in_len) 293 return (0); 294 295 if (h->in[POS_CODE] != RAD_ACCESS_REQUEST) { 296 uint32_t zeroes[4] = { 0, 0, 0, 0 }; 297 /* Check the request authenticator */ 298 MD5Init(&ctx); 299 MD5Update(&ctx, &h->in[POS_CODE], POS_AUTH - POS_CODE); 300 MD5Update(&ctx, zeroes, LEN_AUTH); 301 MD5Update(&ctx, &h->in[POS_ATTRS], len - POS_ATTRS); 302 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 303 MD5Final(md5, &ctx); 304 if (memcmp(&h->in[POS_AUTH], md5, sizeof md5) != 0) 305 return (0); 306 } 307 308 #ifdef WITH_SSL 309 /* Search and verify the Message-Authenticator */ 310 pos = POS_ATTRS; 311 hctx = HMAC_CTX_new(); 312 while (pos < len - 2) { 313 if (h->in[pos] == RAD_MESSAGE_AUTHENTIC) { 314 memcpy(resp, h->in, MSGSIZE); 315 /* zero fill the Request-Authenticator */ 316 if (h->in[POS_CODE] != RAD_ACCESS_REQUEST) 317 memset(&resp[POS_AUTH], 0, LEN_AUTH); 318 /* zero fill the Message-Authenticator */ 319 memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH); 320 321 HMAC_Init_ex(hctx, srvp->secret, 322 strlen(srvp->secret), EVP_md5(), NULL); 323 HMAC_Update(hctx, resp, h->in_len); 324 HMAC_Final(hctx, md, &md_len); 325 HMAC_CTX_reset(hctx); 326 if (memcmp(md, &h->in[pos + 2], 327 MD5_DIGEST_LENGTH) != 0) { 328 HMAC_CTX_free(hctx); 329 return (0); 330 } 331 break; 332 } 333 pos += h->in[pos + 1]; 334 } 335 HMAC_CTX_free(hctx); 336 #endif 337 return (1); 338 } 339 340 static int 341 put_password_attr(struct rad_handle *h, int type, const void *value, size_t len) 342 { 343 int padded_len; 344 int pad_len; 345 346 if (h->pass_pos != 0) { 347 generr(h, "Multiple User-Password attributes specified"); 348 return -1; 349 } 350 if (len > PASSSIZE) 351 len = PASSSIZE; 352 padded_len = len == 0 ? 16 : (len+15) & ~0xf; 353 pad_len = padded_len - len; 354 355 /* 356 * Put in a place-holder attribute containing all zeros, and 357 * remember where it is so we can fill it in later. 358 */ 359 clear_password(h); 360 put_raw_attr(h, type, h->pass, padded_len); 361 h->pass_pos = h->out_len - padded_len; 362 363 /* Save the cleartext password, padded as necessary */ 364 memcpy(h->pass, value, len); 365 h->pass_len = len; 366 memset(h->pass + len, 0, pad_len); 367 return 0; 368 } 369 370 static int 371 put_raw_attr(struct rad_handle *h, int type, const void *value, size_t len) 372 { 373 if (len > 253) { 374 generr(h, "Attribute too long"); 375 return -1; 376 } 377 if (h->out_len + 2 + len > MSGSIZE) { 378 generr(h, "Maximum message length exceeded"); 379 return -1; 380 } 381 h->out[h->out_len++] = type; 382 h->out[h->out_len++] = len + 2; 383 memcpy(&h->out[h->out_len], value, len); 384 h->out_len += len; 385 return 0; 386 } 387 388 int 389 rad_add_server(struct rad_handle *h, const char *host, int port, 390 const char *secret, int timeout, int tries) 391 { 392 struct in_addr bindto; 393 bindto.s_addr = INADDR_ANY; 394 395 return rad_add_server_ex(h, host, port, secret, timeout, tries, 396 DEAD_TIME, &bindto); 397 } 398 399 int 400 rad_add_server_ex(struct rad_handle *h, const char *host, int port, 401 const char *secret, int timeout, int tries, int dead_time, 402 struct in_addr *bindto) 403 { 404 struct rad_server *srvp; 405 406 if (h->num_servers >= MAXSERVERS) { 407 generr(h, "Too many RADIUS servers specified"); 408 return -1; 409 } 410 srvp = &h->servers[h->num_servers]; 411 412 memset(&srvp->addr, 0, sizeof srvp->addr); 413 srvp->addr.sin_len = sizeof srvp->addr; 414 srvp->addr.sin_family = AF_INET; 415 if (!inet_aton(host, &srvp->addr.sin_addr)) { 416 struct hostent *hent; 417 418 if ((hent = gethostbyname(host)) == NULL) { 419 generr(h, "%s: host not found", host); 420 return -1; 421 } 422 memcpy(&srvp->addr.sin_addr, hent->h_addr, 423 sizeof srvp->addr.sin_addr); 424 } 425 if (port != 0) 426 srvp->addr.sin_port = htons((u_short)port); 427 else { 428 struct servent *sent; 429 430 if (h->type == RADIUS_AUTH) 431 srvp->addr.sin_port = 432 (sent = getservbyname("radius", "udp")) != NULL ? 433 sent->s_port : htons(RADIUS_PORT); 434 else 435 srvp->addr.sin_port = 436 (sent = getservbyname("radacct", "udp")) != NULL ? 437 sent->s_port : htons(RADACCT_PORT); 438 } 439 if ((srvp->secret = strdup(secret)) == NULL) { 440 generr(h, "Out of memory"); 441 return -1; 442 } 443 srvp->timeout = timeout; 444 srvp->max_tries = tries; 445 srvp->num_tries = 0; 446 srvp->is_dead = 0; 447 srvp->dead_time = dead_time; 448 srvp->next_probe = 0; 449 srvp->bindto = bindto->s_addr; 450 h->num_servers++; 451 return 0; 452 } 453 454 void 455 rad_close(struct rad_handle *h) 456 { 457 int srv; 458 459 if (h->fd != -1) 460 close(h->fd); 461 for (srv = 0; srv < h->num_servers; srv++) { 462 memset(h->servers[srv].secret, 0, 463 strlen(h->servers[srv].secret)); 464 free(h->servers[srv].secret); 465 } 466 clear_password(h); 467 free(h); 468 } 469 470 void 471 rad_bind_to(struct rad_handle *h, in_addr_t addr) 472 { 473 474 h->bindto = addr; 475 } 476 477 int 478 rad_config(struct rad_handle *h, const char *path) 479 { 480 FILE *fp; 481 char buf[MAXCONFLINE]; 482 int linenum; 483 int retval; 484 485 if (path == NULL) 486 path = PATH_RADIUS_CONF; 487 if ((fp = fopen(path, "r")) == NULL) { 488 generr(h, "Cannot open \"%s\": %s", path, strerror(errno)); 489 return -1; 490 } 491 retval = 0; 492 linenum = 0; 493 while (fgets(buf, sizeof buf, fp) != NULL) { 494 int len; 495 const char *fields[MAX_FIELDS]; 496 int nfields; 497 char msg[ERRSIZE]; 498 const char *type; 499 const char *host; 500 const char *port_str; 501 const char *secret; 502 const char *timeout_str; 503 const char *maxtries_str; 504 const char *dead_time_str; 505 const char *bindto_str; 506 char *res, *host_dup; 507 char *end; 508 const char *wanttype; 509 unsigned long timeout; 510 unsigned long maxtries; 511 unsigned long dead_time; 512 int port; 513 struct in_addr bindto; 514 int i; 515 516 linenum++; 517 len = strlen(buf); 518 /* We know len > 0, else fgets would have returned NULL. */ 519 if (buf[len - 1] != '\n') { 520 if (len == sizeof buf - 1) 521 generr(h, "%s:%d: line too long", path, 522 linenum); 523 else 524 generr(h, "%s:%d: missing newline", path, 525 linenum); 526 retval = -1; 527 break; 528 } 529 buf[len - 1] = '\0'; 530 531 /* Extract the fields from the line. */ 532 nfields = split(buf, fields, MAX_FIELDS, msg, sizeof msg); 533 if (nfields == -1) { 534 generr(h, "%s:%d: %s", path, linenum, msg); 535 retval = -1; 536 break; 537 } 538 if (nfields == 0) 539 continue; 540 /* 541 * The first field should contain "auth" or "acct" for 542 * authentication or accounting, respectively. But older 543 * versions of the file didn't have that field. Default 544 * it to "auth" for backward compatibility. 545 */ 546 if (strcmp(fields[0], "auth") != 0 && 547 strcmp(fields[0], "acct") != 0) { 548 if (nfields >= MAX_FIELDS) { 549 generr(h, "%s:%d: invalid service type", path, 550 linenum); 551 retval = -1; 552 break; 553 } 554 nfields++; 555 for (i = nfields; --i > 0; ) 556 fields[i] = fields[i - 1]; 557 fields[0] = "auth"; 558 } 559 if (nfields < 3) { 560 generr(h, "%s:%d: missing shared secret", path, 561 linenum); 562 retval = -1; 563 break; 564 } 565 type = fields[0]; 566 host = fields[1]; 567 secret = fields[2]; 568 timeout_str = fields[3]; 569 maxtries_str = fields[4]; 570 dead_time_str = fields[5]; 571 bindto_str = fields[6]; 572 573 /* Ignore the line if it is for the wrong service type. */ 574 wanttype = h->type == RADIUS_AUTH ? "auth" : "acct"; 575 if (strcmp(type, wanttype) != 0) 576 continue; 577 578 /* Parse and validate the fields. */ 579 if ((host_dup = strdup(host)) == NULL) { 580 generr(h, "%s:%d: malloc failed", path, linenum); 581 retval = -1; 582 break; 583 } 584 res = host_dup; 585 host = strsep(&res, ":"); 586 port_str = strsep(&res, ":"); 587 if (port_str != NULL) { 588 port = strtoul(port_str, &end, 10); 589 if (*end != '\0') { 590 free(host_dup); 591 generr(h, "%s:%d: invalid port", path, 592 linenum); 593 retval = -1; 594 break; 595 } 596 } else 597 port = 0; 598 if (timeout_str != NULL) { 599 timeout = strtoul(timeout_str, &end, 10); 600 if (*end != '\0') { 601 free(host_dup); 602 generr(h, "%s:%d: invalid timeout", path, 603 linenum); 604 retval = -1; 605 break; 606 } 607 } else 608 timeout = TIMEOUT; 609 if (maxtries_str != NULL) { 610 maxtries = strtoul(maxtries_str, &end, 10); 611 if (*end != '\0') { 612 free(host_dup); 613 generr(h, "%s:%d: invalid maxtries", path, 614 linenum); 615 retval = -1; 616 break; 617 } 618 } else 619 maxtries = MAXTRIES; 620 621 if (dead_time_str != NULL) { 622 dead_time = strtoul(dead_time_str, &end, 10); 623 if (*end != '\0') { 624 free(host_dup); 625 generr(h, "%s:%d: invalid dead_time", path, 626 linenum); 627 retval = -1; 628 break; 629 } 630 } else 631 dead_time = DEAD_TIME; 632 633 if (bindto_str != NULL) { 634 bindto.s_addr = inet_addr(bindto_str); 635 if (bindto.s_addr == INADDR_NONE) { 636 free(host_dup); 637 generr(h, "%s:%d: invalid bindto", path, 638 linenum); 639 retval = -1; 640 break; 641 } 642 } else 643 bindto.s_addr = INADDR_ANY; 644 645 if (rad_add_server_ex(h, host, port, secret, timeout, maxtries, 646 dead_time, &bindto) == -1) { 647 free(host_dup); 648 strcpy(msg, h->errmsg); 649 generr(h, "%s:%d: %s", path, linenum, msg); 650 retval = -1; 651 break; 652 } 653 free(host_dup); 654 } 655 /* Clear out the buffer to wipe a possible copy of a shared secret */ 656 memset(buf, 0, sizeof buf); 657 fclose(fp); 658 return retval; 659 } 660 661 /* 662 * rad_init_send_request() must have previously been called. 663 * Returns: 664 * 0 The application should select on *fd with a timeout of tv before 665 * calling rad_continue_send_request again. 666 * < 0 Failure 667 * > 0 Success 668 */ 669 int 670 rad_continue_send_request(struct rad_handle *h, int selected, int *fd, 671 struct timeval *tv) 672 { 673 int n, cur_srv; 674 time_t now; 675 struct sockaddr_in sin; 676 677 if (h->type == RADIUS_SERVER) { 678 generr(h, "denied function call"); 679 return (-1); 680 } 681 if (selected) { 682 struct sockaddr_in from; 683 socklen_t fromlen; 684 685 fromlen = sizeof from; 686 h->in_len = recvfrom(h->fd, h->in, 687 MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen); 688 if (h->in_len == -1) { 689 generr(h, "recvfrom: %s", strerror(errno)); 690 return -1; 691 } 692 if (is_valid_response(h, h->srv, &from)) { 693 h->in_len = h->in[POS_LENGTH] << 8 | 694 h->in[POS_LENGTH+1]; 695 h->in_pos = POS_ATTRS; 696 return h->in[POS_CODE]; 697 } 698 } 699 700 /* 701 * Scan round-robin to the next server that has some 702 * tries left. There is guaranteed to be one, or we 703 * would have exited this loop by now. 704 */ 705 cur_srv = h->srv; 706 now = time(NULL); 707 if (h->servers[h->srv].num_tries >= h->servers[h->srv].max_tries) { 708 /* Set next probe time for this server */ 709 if (h->servers[h->srv].dead_time) { 710 h->servers[h->srv].is_dead = 1; 711 h->servers[h->srv].next_probe = now + 712 h->servers[h->srv].dead_time; 713 } 714 do { 715 h->srv++; 716 if (h->srv >= h->num_servers) 717 h->srv = 0; 718 if (h->servers[h->srv].is_dead == 0) 719 break; 720 if (h->servers[h->srv].dead_time && 721 h->servers[h->srv].next_probe <= now) { 722 h->servers[h->srv].is_dead = 0; 723 h->servers[h->srv].num_tries = 0; 724 break; 725 } 726 } while (h->srv != cur_srv); 727 728 if (h->srv == cur_srv) { 729 generr(h, "No valid RADIUS responses received"); 730 return (-1); 731 } 732 } 733 734 /* Rebind */ 735 if (h->bindto != h->servers[h->srv].bindto) { 736 h->bindto = h->servers[h->srv].bindto; 737 close(h->fd); 738 if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) { 739 generr(h, "Cannot create socket: %s", strerror(errno)); 740 return -1; 741 } 742 memset(&sin, 0, sizeof sin); 743 sin.sin_len = sizeof sin; 744 sin.sin_family = AF_INET; 745 sin.sin_addr.s_addr = h->bindto; 746 sin.sin_port = 0; 747 if (bind(h->fd, (const struct sockaddr *)&sin, 748 sizeof sin) == -1) { 749 generr(h, "bind: %s", strerror(errno)); 750 close(h->fd); 751 h->fd = -1; 752 return (-1); 753 } 754 } 755 756 if (h->out[POS_CODE] == RAD_ACCESS_REQUEST) { 757 /* Insert the scrambled password into the request */ 758 if (h->pass_pos != 0) 759 insert_scrambled_password(h, h->srv); 760 } 761 insert_message_authenticator(h, 0); 762 763 if (h->out[POS_CODE] != RAD_ACCESS_REQUEST) { 764 /* Insert the request authenticator into the request */ 765 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 766 insert_request_authenticator(h, 0); 767 } 768 769 /* Send the request */ 770 n = sendto(h->fd, h->out, h->out_len, 0, 771 (const struct sockaddr *)&h->servers[h->srv].addr, 772 sizeof h->servers[h->srv].addr); 773 if (n != h->out_len) 774 tv->tv_sec = 1; /* Do not wait full timeout if send failed. */ 775 else 776 tv->tv_sec = h->servers[h->srv].timeout; 777 h->servers[h->srv].num_tries++; 778 tv->tv_usec = 0; 779 *fd = h->fd; 780 781 return 0; 782 } 783 784 int 785 rad_receive_request(struct rad_handle *h) 786 { 787 struct sockaddr_in from; 788 socklen_t fromlen; 789 int n; 790 791 if (h->type != RADIUS_SERVER) { 792 generr(h, "denied function call"); 793 return (-1); 794 } 795 h->srv = -1; 796 fromlen = sizeof(from); 797 h->in_len = recvfrom(h->fd, h->in, 798 MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen); 799 if (h->in_len == -1) { 800 generr(h, "recvfrom: %s", strerror(errno)); 801 return (-1); 802 } 803 for (n = 0; n < h->num_servers; n++) { 804 if (h->servers[n].addr.sin_addr.s_addr == from.sin_addr.s_addr) { 805 h->servers[n].addr.sin_port = from.sin_port; 806 h->srv = n; 807 break; 808 } 809 } 810 if (h->srv == -1) 811 return (-2); 812 if (is_valid_request(h)) { 813 h->in_len = h->in[POS_LENGTH] << 8 | 814 h->in[POS_LENGTH+1]; 815 h->in_pos = POS_ATTRS; 816 return (h->in[POS_CODE]); 817 } 818 return (-3); 819 } 820 821 int 822 rad_send_response(struct rad_handle *h) 823 { 824 int n; 825 826 if (h->type != RADIUS_SERVER) { 827 generr(h, "denied function call"); 828 return (-1); 829 } 830 /* Fill in the length field in the message */ 831 h->out[POS_LENGTH] = h->out_len >> 8; 832 h->out[POS_LENGTH+1] = h->out_len; 833 834 insert_message_authenticator(h, 835 (h->in[POS_CODE] == RAD_ACCESS_REQUEST) ? 1 : 0); 836 insert_request_authenticator(h, 1); 837 838 /* Send the request */ 839 n = sendto(h->fd, h->out, h->out_len, 0, 840 (const struct sockaddr *)&h->servers[h->srv].addr, 841 sizeof h->servers[h->srv].addr); 842 if (n != h->out_len) { 843 if (n == -1) 844 generr(h, "sendto: %s", strerror(errno)); 845 else 846 generr(h, "sendto: short write"); 847 return -1; 848 } 849 850 return 0; 851 } 852 853 int 854 rad_create_request(struct rad_handle *h, int code) 855 { 856 int i; 857 858 if (h->type == RADIUS_SERVER) { 859 generr(h, "denied function call"); 860 return (-1); 861 } 862 if (h->num_servers == 0) { 863 generr(h, "No RADIUS servers specified"); 864 return (-1); 865 } 866 h->out[POS_CODE] = code; 867 h->out[POS_IDENT] = ++h->ident; 868 if (code == RAD_ACCESS_REQUEST) { 869 /* Create a random authenticator */ 870 for (i = 0; i < LEN_AUTH; i += 2) { 871 long r; 872 r = random(); 873 h->out[POS_AUTH+i] = (u_char)r; 874 h->out[POS_AUTH+i+1] = (u_char)(r >> 8); 875 } 876 } else 877 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 878 h->out_len = POS_ATTRS; 879 clear_password(h); 880 h->authentic_pos = 0; 881 h->out_created = 1; 882 return 0; 883 } 884 885 int 886 rad_create_response(struct rad_handle *h, int code) 887 { 888 889 if (h->type != RADIUS_SERVER) { 890 generr(h, "denied function call"); 891 return (-1); 892 } 893 h->out[POS_CODE] = code; 894 h->out[POS_IDENT] = h->in[POS_IDENT]; 895 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 896 h->out_len = POS_ATTRS; 897 clear_password(h); 898 h->authentic_pos = 0; 899 h->out_created = 1; 900 return 0; 901 } 902 903 struct in_addr 904 rad_cvt_addr(const void *data) 905 { 906 struct in_addr value; 907 908 memcpy(&value.s_addr, data, sizeof value.s_addr); 909 return value; 910 } 911 912 struct in6_addr 913 rad_cvt_addr6(const void *data) 914 { 915 struct in6_addr value; 916 917 memcpy(&value.s6_addr, data, sizeof value.s6_addr); 918 return value; 919 } 920 921 u_int32_t 922 rad_cvt_int(const void *data) 923 { 924 u_int32_t value; 925 926 memcpy(&value, data, sizeof value); 927 return ntohl(value); 928 } 929 930 char * 931 rad_cvt_string(const void *data, size_t len) 932 { 933 char *s; 934 935 s = malloc(len + 1); 936 if (s != NULL) { 937 memcpy(s, data, len); 938 s[len] = '\0'; 939 } 940 return s; 941 } 942 943 /* 944 * Returns the attribute type. If none are left, returns 0. On failure, 945 * returns -1. 946 */ 947 int 948 rad_get_attr(struct rad_handle *h, const void **value, size_t *len) 949 { 950 int type; 951 952 if (h->in_pos >= h->in_len) 953 return 0; 954 if (h->in_pos + 2 > h->in_len) { 955 generr(h, "Malformed attribute in response"); 956 return -1; 957 } 958 type = h->in[h->in_pos++]; 959 *len = h->in[h->in_pos++] - 2; 960 if (h->in_pos + (int)*len > h->in_len) { 961 generr(h, "Malformed attribute in response"); 962 return -1; 963 } 964 *value = &h->in[h->in_pos]; 965 h->in_pos += *len; 966 return type; 967 } 968 969 /* 970 * Returns -1 on error, 0 to indicate no event and >0 for success 971 */ 972 int 973 rad_init_send_request(struct rad_handle *h, int *fd, struct timeval *tv) 974 { 975 int srv; 976 time_t now; 977 struct sockaddr_in sin; 978 979 if (h->type == RADIUS_SERVER) { 980 generr(h, "denied function call"); 981 return (-1); 982 } 983 /* Make sure we have a socket to use */ 984 if (h->fd == -1) { 985 if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) { 986 generr(h, "Cannot create socket: %s", strerror(errno)); 987 return -1; 988 } 989 memset(&sin, 0, sizeof sin); 990 sin.sin_len = sizeof sin; 991 sin.sin_family = AF_INET; 992 sin.sin_addr.s_addr = h->bindto; 993 sin.sin_port = htons(0); 994 if (bind(h->fd, (const struct sockaddr *)&sin, 995 sizeof sin) == -1) { 996 generr(h, "bind: %s", strerror(errno)); 997 close(h->fd); 998 h->fd = -1; 999 return -1; 1000 } 1001 } 1002 1003 if (h->out[POS_CODE] != RAD_ACCESS_REQUEST) { 1004 /* Make sure no password given */ 1005 if (h->pass_pos || h->chap_pass) { 1006 generr(h, "User or Chap Password" 1007 " in accounting request"); 1008 return -1; 1009 } 1010 } else { 1011 if (h->eap_msg == 0) { 1012 /* Make sure the user gave us a password */ 1013 if (h->pass_pos == 0 && !h->chap_pass) { 1014 generr(h, "No User or Chap Password" 1015 " attributes given"); 1016 return -1; 1017 } 1018 if (h->pass_pos != 0 && h->chap_pass) { 1019 generr(h, "Both User and Chap Password" 1020 " attributes given"); 1021 return -1; 1022 } 1023 } 1024 } 1025 1026 /* Fill in the length field in the message */ 1027 h->out[POS_LENGTH] = h->out_len >> 8; 1028 h->out[POS_LENGTH+1] = h->out_len; 1029 1030 h->srv = 0; 1031 now = time(NULL); 1032 for (srv = 0; srv < h->num_servers; srv++) 1033 h->servers[srv].num_tries = 0; 1034 /* Find a first good server. */ 1035 for (srv = 0; srv < h->num_servers; srv++) { 1036 if (h->servers[srv].is_dead == 0) 1037 break; 1038 if (h->servers[srv].dead_time && 1039 h->servers[srv].next_probe <= now) { 1040 h->servers[srv].is_dead = 0; 1041 break; 1042 } 1043 h->srv++; 1044 } 1045 1046 /* If all servers was dead on the last probe, try from beginning */ 1047 if (h->srv == h->num_servers) { 1048 for (srv = 0; srv < h->num_servers; srv++) { 1049 h->servers[srv].is_dead = 0; 1050 h->servers[srv].next_probe = 0; 1051 } 1052 h->srv = 0; 1053 } 1054 1055 return rad_continue_send_request(h, 0, fd, tv); 1056 } 1057 1058 /* 1059 * Create and initialize a rad_handle structure, and return it to the 1060 * caller. Can fail only if the necessary memory cannot be allocated. 1061 * In that case, it returns NULL. 1062 */ 1063 struct rad_handle * 1064 rad_auth_open(void) 1065 { 1066 struct rad_handle *h; 1067 1068 h = (struct rad_handle *)malloc(sizeof(struct rad_handle)); 1069 if (h != NULL) { 1070 srandomdev(); 1071 h->fd = -1; 1072 h->num_servers = 0; 1073 h->ident = random(); 1074 h->errmsg[0] = '\0'; 1075 memset(h->pass, 0, sizeof h->pass); 1076 h->pass_len = 0; 1077 h->pass_pos = 0; 1078 h->chap_pass = 0; 1079 h->authentic_pos = 0; 1080 h->type = RADIUS_AUTH; 1081 h->out_created = 0; 1082 h->eap_msg = 0; 1083 h->bindto = INADDR_ANY; 1084 } 1085 return h; 1086 } 1087 1088 struct rad_handle * 1089 rad_acct_open(void) 1090 { 1091 struct rad_handle *h; 1092 1093 h = rad_open(); 1094 if (h != NULL) 1095 h->type = RADIUS_ACCT; 1096 return h; 1097 } 1098 1099 struct rad_handle * 1100 rad_server_open(int fd) 1101 { 1102 struct rad_handle *h; 1103 1104 h = rad_open(); 1105 if (h != NULL) { 1106 h->type = RADIUS_SERVER; 1107 h->fd = fd; 1108 } 1109 return h; 1110 } 1111 1112 struct rad_handle * 1113 rad_open(void) 1114 { 1115 return rad_auth_open(); 1116 } 1117 1118 int 1119 rad_put_addr(struct rad_handle *h, int type, struct in_addr addr) 1120 { 1121 return rad_put_attr(h, type, &addr.s_addr, sizeof addr.s_addr); 1122 } 1123 1124 int 1125 rad_put_addr6(struct rad_handle *h, int type, struct in6_addr addr) 1126 { 1127 1128 return rad_put_attr(h, type, &addr.s6_addr, sizeof addr.s6_addr); 1129 } 1130 1131 int 1132 rad_put_attr(struct rad_handle *h, int type, const void *value, size_t len) 1133 { 1134 int result; 1135 1136 if (!h->out_created) { 1137 generr(h, "Please call rad_create_request()" 1138 " before putting attributes"); 1139 return -1; 1140 } 1141 1142 if (h->out[POS_CODE] == RAD_ACCOUNTING_REQUEST) { 1143 if (type == RAD_EAP_MESSAGE) { 1144 generr(h, "EAP-Message attribute is not valid" 1145 " in accounting requests"); 1146 return -1; 1147 } 1148 } 1149 1150 /* 1151 * When proxying EAP Messages, the Message Authenticator 1152 * MUST be present; see RFC 3579. 1153 */ 1154 if (type == RAD_EAP_MESSAGE) { 1155 if (rad_put_message_authentic(h) == -1) 1156 return -1; 1157 } 1158 1159 if (type == RAD_USER_PASSWORD) { 1160 result = put_password_attr(h, type, value, len); 1161 } else if (type == RAD_MESSAGE_AUTHENTIC) { 1162 result = rad_put_message_authentic(h); 1163 } else { 1164 result = put_raw_attr(h, type, value, len); 1165 if (result == 0) { 1166 if (type == RAD_CHAP_PASSWORD) 1167 h->chap_pass = 1; 1168 else if (type == RAD_EAP_MESSAGE) 1169 h->eap_msg = 1; 1170 } 1171 } 1172 1173 return result; 1174 } 1175 1176 int 1177 rad_put_int(struct rad_handle *h, int type, u_int32_t value) 1178 { 1179 u_int32_t nvalue; 1180 1181 nvalue = htonl(value); 1182 return rad_put_attr(h, type, &nvalue, sizeof nvalue); 1183 } 1184 1185 int 1186 rad_put_string(struct rad_handle *h, int type, const char *str) 1187 { 1188 return rad_put_attr(h, type, str, strlen(str)); 1189 } 1190 1191 int 1192 rad_put_message_authentic(struct rad_handle *h) 1193 { 1194 #ifdef WITH_SSL 1195 u_char md_zero[MD5_DIGEST_LENGTH]; 1196 1197 if (h->out[POS_CODE] == RAD_ACCOUNTING_REQUEST) { 1198 generr(h, "Message-Authenticator is not valid" 1199 " in accounting requests"); 1200 return -1; 1201 } 1202 1203 if (h->authentic_pos == 0) { 1204 h->authentic_pos = h->out_len; 1205 memset(md_zero, 0, sizeof(md_zero)); 1206 return (put_raw_attr(h, RAD_MESSAGE_AUTHENTIC, md_zero, 1207 sizeof(md_zero))); 1208 } 1209 return 0; 1210 #else 1211 generr(h, "Message Authenticator not supported," 1212 " please recompile libradius with SSL support"); 1213 return -1; 1214 #endif 1215 } 1216 1217 /* 1218 * Returns the response type code on success, or -1 on failure. 1219 */ 1220 int 1221 rad_send_request(struct rad_handle *h) 1222 { 1223 struct timeval timelimit; 1224 struct timeval tv; 1225 int fd; 1226 int n; 1227 1228 n = rad_init_send_request(h, &fd, &tv); 1229 1230 if (n != 0) 1231 return n; 1232 1233 gettimeofday(&timelimit, NULL); 1234 timeradd(&tv, &timelimit, &timelimit); 1235 1236 for ( ; ; ) { 1237 fd_set readfds; 1238 1239 FD_ZERO(&readfds); 1240 FD_SET(fd, &readfds); 1241 1242 n = select(fd + 1, &readfds, NULL, NULL, &tv); 1243 1244 if (n == -1) { 1245 generr(h, "select: %s", strerror(errno)); 1246 return -1; 1247 } 1248 1249 if (!FD_ISSET(fd, &readfds)) { 1250 /* Compute a new timeout */ 1251 gettimeofday(&tv, NULL); 1252 timersub(&timelimit, &tv, &tv); 1253 if (tv.tv_sec > 0 || (tv.tv_sec == 0 && tv.tv_usec > 0)) 1254 /* Continue the select */ 1255 continue; 1256 } 1257 1258 n = rad_continue_send_request(h, n, &fd, &tv); 1259 1260 if (n != 0) 1261 return n; 1262 1263 gettimeofday(&timelimit, NULL); 1264 timeradd(&tv, &timelimit, &timelimit); 1265 } 1266 } 1267 1268 const char * 1269 rad_strerror(struct rad_handle *h) 1270 { 1271 return h->errmsg; 1272 } 1273 1274 /* 1275 * Destructively split a string into fields separated by white space. 1276 * `#' at the beginning of a field begins a comment that extends to the 1277 * end of the string. Fields may be quoted with `"'. Inside quoted 1278 * strings, the backslash escapes `\"' and `\\' are honored. 1279 * 1280 * Pointers to up to the first maxfields fields are stored in the fields 1281 * array. Missing fields get NULL pointers. 1282 * 1283 * The return value is the actual number of fields parsed, and is always 1284 * <= maxfields. 1285 * 1286 * On a syntax error, places a message in the msg string, and returns -1. 1287 */ 1288 static int 1289 split(char *str, const char *fields[], int maxfields, char *msg, size_t msglen) 1290 { 1291 char *p; 1292 int i; 1293 static const char ws[] = " \t"; 1294 1295 for (i = 0; i < maxfields; i++) 1296 fields[i] = NULL; 1297 p = str; 1298 i = 0; 1299 while (*p != '\0') { 1300 p += strspn(p, ws); 1301 if (*p == '#' || *p == '\0') 1302 break; 1303 if (i >= maxfields) { 1304 snprintf(msg, msglen, "line has too many fields"); 1305 return -1; 1306 } 1307 if (*p == '"') { 1308 char *dst; 1309 1310 dst = ++p; 1311 fields[i] = dst; 1312 while (*p != '"') { 1313 if (*p == '\\') { 1314 p++; 1315 if (*p != '"' && *p != '\\' && 1316 *p != '\0') { 1317 snprintf(msg, msglen, 1318 "invalid `\\' escape"); 1319 return -1; 1320 } 1321 } 1322 if (*p == '\0') { 1323 snprintf(msg, msglen, 1324 "unterminated quoted string"); 1325 return -1; 1326 } 1327 *dst++ = *p++; 1328 } 1329 *dst = '\0'; 1330 p++; 1331 if (*fields[i] == '\0') { 1332 snprintf(msg, msglen, 1333 "empty quoted string not permitted"); 1334 return -1; 1335 } 1336 if (*p != '\0' && strspn(p, ws) == 0) { 1337 snprintf(msg, msglen, "quoted string not" 1338 " followed by white space"); 1339 return -1; 1340 } 1341 } else { 1342 fields[i] = p; 1343 p += strcspn(p, ws); 1344 if (*p != '\0') 1345 *p++ = '\0'; 1346 } 1347 i++; 1348 } 1349 return i; 1350 } 1351 1352 int 1353 rad_get_vendor_attr(u_int32_t *vendor, const void **data, size_t *len) 1354 { 1355 const struct vendor_attribute *attr; 1356 1357 attr = (const struct vendor_attribute *)*data; 1358 *vendor = ntohl(attr->vendor_value); 1359 *data = attr->attrib_data; 1360 *len = attr->attrib_len - 2; 1361 1362 return (attr->attrib_type); 1363 } 1364 1365 int 1366 rad_put_vendor_addr(struct rad_handle *h, int vendor, int type, 1367 struct in_addr addr) 1368 { 1369 return (rad_put_vendor_attr(h, vendor, type, &addr.s_addr, 1370 sizeof addr.s_addr)); 1371 } 1372 1373 int 1374 rad_put_vendor_addr6(struct rad_handle *h, int vendor, int type, 1375 struct in6_addr addr) 1376 { 1377 1378 return (rad_put_vendor_attr(h, vendor, type, &addr.s6_addr, 1379 sizeof addr.s6_addr)); 1380 } 1381 1382 int 1383 rad_put_vendor_attr(struct rad_handle *h, int vendor, int type, 1384 const void *value, size_t len) 1385 { 1386 struct vendor_attribute *attr; 1387 int res; 1388 1389 if (!h->out_created) { 1390 generr(h, "Please call rad_create_request()" 1391 " before putting attributes"); 1392 return -1; 1393 } 1394 1395 if ((attr = malloc(len + 6)) == NULL) { 1396 generr(h, "malloc failure (%zu bytes)", len + 6); 1397 return -1; 1398 } 1399 1400 attr->vendor_value = htonl(vendor); 1401 attr->attrib_type = type; 1402 attr->attrib_len = len + 2; 1403 memcpy(attr->attrib_data, value, len); 1404 1405 res = put_raw_attr(h, RAD_VENDOR_SPECIFIC, attr, len + 6); 1406 free(attr); 1407 if (res == 0 && vendor == RAD_VENDOR_MICROSOFT 1408 && (type == RAD_MICROSOFT_MS_CHAP_RESPONSE 1409 || type == RAD_MICROSOFT_MS_CHAP2_RESPONSE)) { 1410 h->chap_pass = 1; 1411 } 1412 return (res); 1413 } 1414 1415 int 1416 rad_put_vendor_int(struct rad_handle *h, int vendor, int type, u_int32_t i) 1417 { 1418 u_int32_t value; 1419 1420 value = htonl(i); 1421 return (rad_put_vendor_attr(h, vendor, type, &value, sizeof value)); 1422 } 1423 1424 int 1425 rad_put_vendor_string(struct rad_handle *h, int vendor, int type, 1426 const char *str) 1427 { 1428 return (rad_put_vendor_attr(h, vendor, type, str, strlen(str))); 1429 } 1430 1431 ssize_t 1432 rad_request_authenticator(struct rad_handle *h, char *buf, size_t len) 1433 { 1434 if (len < LEN_AUTH) 1435 return (-1); 1436 memcpy(buf, h->out + POS_AUTH, LEN_AUTH); 1437 if (len > LEN_AUTH) 1438 buf[LEN_AUTH] = '\0'; 1439 return (LEN_AUTH); 1440 } 1441 1442 u_char * 1443 rad_demangle(struct rad_handle *h, const void *mangled, size_t mlen) 1444 { 1445 char R[LEN_AUTH]; 1446 const char *S; 1447 int i, Ppos; 1448 MD5_CTX Context; 1449 u_char b[MD5_DIGEST_LENGTH], *demangled; 1450 const u_char *C; 1451 1452 if ((mlen % 16 != 0) || mlen > 128) { 1453 generr(h, "Cannot interpret mangled data of length %lu", 1454 (u_long)mlen); 1455 return NULL; 1456 } 1457 1458 C = mangled; 1459 1460 /* We need the shared secret as Salt */ 1461 S = rad_server_secret(h); 1462 1463 /* We need the request authenticator */ 1464 if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) { 1465 generr(h, "Cannot obtain the RADIUS request authenticator"); 1466 return NULL; 1467 } 1468 1469 demangled = malloc(mlen); 1470 if (!demangled) 1471 return NULL; 1472 1473 MD5Init(&Context); 1474 MD5Update(&Context, S, strlen(S)); 1475 MD5Update(&Context, R, LEN_AUTH); 1476 MD5Final(b, &Context); 1477 Ppos = 0; 1478 while (mlen) { 1479 1480 mlen -= 16; 1481 for (i = 0; i < 16; i++) 1482 demangled[Ppos++] = C[i] ^ b[i]; 1483 1484 if (mlen) { 1485 MD5Init(&Context); 1486 MD5Update(&Context, S, strlen(S)); 1487 MD5Update(&Context, C, 16); 1488 MD5Final(b, &Context); 1489 } 1490 1491 C += 16; 1492 } 1493 1494 return demangled; 1495 } 1496 1497 u_char * 1498 rad_demangle_mppe_key(struct rad_handle *h, const void *mangled, 1499 size_t mlen, size_t *len) 1500 { 1501 char R[LEN_AUTH]; /* variable names as per rfc2548 */ 1502 const char *S; 1503 u_char b[MD5_DIGEST_LENGTH], *demangled; 1504 const u_char *A, *C; 1505 MD5_CTX Context; 1506 int Slen, i, Clen, Ppos; 1507 u_char *P; 1508 1509 if (mlen % 16 != SALT_LEN) { 1510 generr(h, "Cannot interpret mangled data of length %lu", 1511 (u_long)mlen); 1512 return NULL; 1513 } 1514 1515 /* We need the RADIUS Request-Authenticator */ 1516 if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) { 1517 generr(h, "Cannot obtain the RADIUS request authenticator"); 1518 return NULL; 1519 } 1520 1521 A = (const u_char *)mangled; /* Salt comes first */ 1522 C = (const u_char *)mangled + SALT_LEN; /* Then the ciphertext */ 1523 Clen = mlen - SALT_LEN; 1524 S = rad_server_secret(h); /* We need the RADIUS secret */ 1525 Slen = strlen(S); 1526 P = alloca(Clen); /* We derive our plaintext */ 1527 1528 MD5Init(&Context); 1529 MD5Update(&Context, S, Slen); 1530 MD5Update(&Context, R, LEN_AUTH); 1531 MD5Update(&Context, A, SALT_LEN); 1532 MD5Final(b, &Context); 1533 Ppos = 0; 1534 1535 while (Clen) { 1536 Clen -= 16; 1537 1538 for (i = 0; i < 16; i++) 1539 P[Ppos++] = C[i] ^ b[i]; 1540 1541 if (Clen) { 1542 MD5Init(&Context); 1543 MD5Update(&Context, S, Slen); 1544 MD5Update(&Context, C, 16); 1545 MD5Final(b, &Context); 1546 } 1547 1548 C += 16; 1549 } 1550 1551 /* 1552 * The resulting plain text consists of a one-byte length, the text and 1553 * maybe some padding. 1554 */ 1555 *len = *P; 1556 if (*len > mlen - 1) { 1557 generr(h, "Mangled data seems to be garbage %zu %zu", 1558 *len, mlen-1); 1559 return NULL; 1560 } 1561 1562 if (*len > MPPE_KEY_LEN * 2) { 1563 generr(h, "Key to long (%zu) for me max. %d", 1564 *len, MPPE_KEY_LEN * 2); 1565 return NULL; 1566 } 1567 demangled = malloc(*len); 1568 if (!demangled) 1569 return NULL; 1570 1571 memcpy(demangled, P + 1, *len); 1572 return demangled; 1573 } 1574 1575 const char * 1576 rad_server_secret(struct rad_handle *h) 1577 { 1578 return (h->servers[h->srv].secret); 1579 } 1580