1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright 1998 Juniper Networks, Inc. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/types.h> 30 #include <sys/socket.h> 31 #include <sys/time.h> 32 #include <netinet/in.h> 33 #include <arpa/inet.h> 34 #ifdef WITH_SSL 35 #include <openssl/hmac.h> 36 #include <openssl/md5.h> 37 #define MD5Init MD5_Init 38 #define MD5Update MD5_Update 39 #define MD5Final MD5_Final 40 #else 41 #define MD5_DIGEST_LENGTH 16 42 #include <md5.h> 43 #endif 44 45 #define MAX_FIELDS 7 46 47 /* We need the MPPE_KEY_LEN define */ 48 #include <netgraph/ng_mppc.h> 49 50 #include <errno.h> 51 #include <netdb.h> 52 #include <stdarg.h> 53 #include <stddef.h> 54 #include <stdio.h> 55 #include <stdlib.h> 56 #include <string.h> 57 #include <unistd.h> 58 59 #include "radlib_private.h" 60 61 static void clear_password(struct rad_handle *); 62 static void generr(struct rad_handle *, const char *, ...) 63 __printflike(2, 3); 64 static void insert_scrambled_password(struct rad_handle *, int); 65 static void insert_request_authenticator(struct rad_handle *, int); 66 static void insert_message_authenticator(struct rad_handle *, int); 67 static int is_valid_response(struct rad_handle *, int, 68 const struct sockaddr_in *); 69 static int put_password_attr(struct rad_handle *, int, 70 const void *, size_t); 71 static int put_raw_attr(struct rad_handle *, int, 72 const void *, size_t); 73 static int split(char *, char *[], int, char *, size_t); 74 75 static void 76 clear_password(struct rad_handle *h) 77 { 78 if (h->pass_len != 0) { 79 explicit_bzero(h->pass, h->pass_len); 80 h->pass_len = 0; 81 } 82 h->pass_pos = 0; 83 } 84 85 static void 86 generr(struct rad_handle *h, const char *format, ...) 87 { 88 va_list ap; 89 90 va_start(ap, format); 91 vsnprintf(h->errmsg, ERRSIZE, format, ap); 92 va_end(ap); 93 } 94 95 static void 96 insert_scrambled_password(struct rad_handle *h, int srv) 97 { 98 MD5_CTX ctx; 99 unsigned char md5[MD5_DIGEST_LENGTH]; 100 const struct rad_server *srvp; 101 int padded_len; 102 int pos; 103 104 srvp = &h->servers[srv]; 105 padded_len = h->pass_len == 0 ? 16 : (h->pass_len+15) & ~0xf; 106 107 memcpy(md5, &h->out[POS_AUTH], LEN_AUTH); 108 for (pos = 0; pos < padded_len; pos += 16) { 109 int i; 110 111 /* Calculate the new scrambler */ 112 MD5Init(&ctx); 113 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 114 MD5Update(&ctx, md5, 16); 115 MD5Final(md5, &ctx); 116 117 /* 118 * Mix in the current chunk of the password, and copy 119 * the result into the right place in the request. Also 120 * modify the scrambler in place, since we will use this 121 * in calculating the scrambler for next time. 122 */ 123 for (i = 0; i < 16; i++) 124 h->out[h->pass_pos + pos + i] = 125 md5[i] ^= h->pass[pos + i]; 126 } 127 } 128 129 static void 130 insert_request_authenticator(struct rad_handle *h, int resp) 131 { 132 MD5_CTX ctx; 133 const struct rad_server *srvp; 134 135 srvp = &h->servers[h->srv]; 136 137 /* Create the request authenticator */ 138 MD5Init(&ctx); 139 MD5Update(&ctx, &h->out[POS_CODE], POS_AUTH - POS_CODE); 140 if (resp) 141 MD5Update(&ctx, &h->in[POS_AUTH], LEN_AUTH); 142 else 143 MD5Update(&ctx, &h->out[POS_AUTH], LEN_AUTH); 144 MD5Update(&ctx, &h->out[POS_ATTRS], h->out_len - POS_ATTRS); 145 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 146 MD5Final(&h->out[POS_AUTH], &ctx); 147 } 148 149 static void 150 insert_message_authenticator(struct rad_handle *h, int resp) 151 { 152 #ifdef WITH_SSL 153 u_char md[EVP_MAX_MD_SIZE]; 154 u_int md_len; 155 const struct rad_server *srvp; 156 HMAC_CTX *ctx; 157 srvp = &h->servers[h->srv]; 158 159 if (h->authentic_pos != 0) { 160 ctx = HMAC_CTX_new(); 161 HMAC_Init_ex(ctx, srvp->secret, strlen(srvp->secret), EVP_md5(), NULL); 162 HMAC_Update(ctx, &h->out[POS_CODE], POS_AUTH - POS_CODE); 163 if (resp) 164 HMAC_Update(ctx, &h->in[POS_AUTH], LEN_AUTH); 165 else 166 HMAC_Update(ctx, &h->out[POS_AUTH], LEN_AUTH); 167 HMAC_Update(ctx, &h->out[POS_ATTRS], 168 h->out_len - POS_ATTRS); 169 HMAC_Final(ctx, md, &md_len); 170 HMAC_CTX_free(ctx); 171 memcpy(&h->out[h->authentic_pos + 2], md, md_len); 172 } 173 #endif 174 } 175 176 /* 177 * Return true if the current response is valid for a request to the 178 * specified server. 179 */ 180 static int 181 is_valid_response(struct rad_handle *h, int srv, 182 const struct sockaddr_in *from) 183 { 184 MD5_CTX ctx; 185 unsigned char md5[MD5_DIGEST_LENGTH]; 186 const struct rad_server *srvp; 187 188 int len; 189 #ifdef WITH_SSL 190 int alen; 191 HMAC_CTX *hctx; 192 u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE]; 193 u_int md_len; 194 int pos; 195 #endif 196 197 srvp = &h->servers[srv]; 198 199 /* Check the source address */ 200 if (from->sin_family != srvp->addr.sin_family || 201 from->sin_addr.s_addr != srvp->addr.sin_addr.s_addr || 202 from->sin_port != srvp->addr.sin_port) 203 return 0; 204 205 /* Check the message length */ 206 if (h->in_len < POS_ATTRS) 207 return 0; 208 len = (h->in[POS_LENGTH] << 8) | h->in[POS_LENGTH + 1]; 209 if (len < POS_ATTRS || len > h->in_len) 210 return 0; 211 212 /* Check the response authenticator */ 213 MD5Init(&ctx); 214 MD5Update(&ctx, &h->in[POS_CODE], POS_AUTH - POS_CODE); 215 MD5Update(&ctx, &h->out[POS_AUTH], LEN_AUTH); 216 MD5Update(&ctx, &h->in[POS_ATTRS], len - POS_ATTRS); 217 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 218 MD5Final(md5, &ctx); 219 if (memcmp(&h->in[POS_AUTH], md5, sizeof md5) != 0) 220 return 0; 221 222 #ifdef WITH_SSL 223 /* 224 * For non accounting responses check the message authenticator, 225 * if any. 226 */ 227 if (h->in[POS_CODE] != RAD_ACCOUNTING_RESPONSE) { 228 229 memcpy(resp, h->in, MSGSIZE); 230 pos = POS_ATTRS; 231 232 /* Search and verify the Message-Authenticator */ 233 hctx = HMAC_CTX_new(); 234 while (pos < len - 2) { 235 if (h->in[pos] == RAD_MESSAGE_AUTHENTIC) { 236 if (h->in[pos + 1] != MD5_DIGEST_LENGTH + 2) { 237 HMAC_CTX_free(hctx); 238 return 0; 239 } 240 if (len - pos < MD5_DIGEST_LENGTH + 2) { 241 HMAC_CTX_free(hctx); 242 return 0; 243 } 244 245 memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH); 246 247 HMAC_Init_ex(hctx, srvp->secret, 248 strlen(srvp->secret), EVP_md5(), NULL); 249 HMAC_Update(hctx, &h->in[POS_CODE], 250 POS_AUTH - POS_CODE); 251 HMAC_Update(hctx, &h->out[POS_AUTH], 252 LEN_AUTH); 253 HMAC_Update(hctx, &resp[POS_ATTRS], 254 h->in_len - POS_ATTRS); 255 HMAC_Final(hctx, md, &md_len); 256 HMAC_CTX_reset(hctx); 257 if (memcmp(md, &h->in[pos + 2], 258 MD5_DIGEST_LENGTH) != 0) { 259 HMAC_CTX_free(hctx); 260 return 0; 261 } 262 break; 263 } 264 alen = h->in[pos + 1]; 265 if (alen < 2) { 266 HMAC_CTX_free(hctx); 267 return 0; 268 } 269 pos += alen; 270 } 271 HMAC_CTX_free(hctx); 272 } 273 #endif 274 return 1; 275 } 276 277 /* 278 * Return true if the current request is valid for the specified server. 279 */ 280 static int 281 is_valid_request(struct rad_handle *h) 282 { 283 MD5_CTX ctx; 284 unsigned char md5[MD5_DIGEST_LENGTH]; 285 const struct rad_server *srvp; 286 int len; 287 #ifdef WITH_SSL 288 int alen; 289 HMAC_CTX *hctx; 290 u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE]; 291 u_int md_len; 292 int pos; 293 #endif 294 295 srvp = &h->servers[h->srv]; 296 297 /* Check the message length */ 298 if (h->in_len < POS_ATTRS) 299 return (0); 300 len = (h->in[POS_LENGTH] << 8) | h->in[POS_LENGTH + 1]; 301 if (len < POS_ATTRS || len > h->in_len) 302 return (0); 303 304 if (h->in[POS_CODE] != RAD_ACCESS_REQUEST) { 305 uint32_t zeroes[4] = { 0, 0, 0, 0 }; 306 /* Check the request authenticator */ 307 MD5Init(&ctx); 308 MD5Update(&ctx, &h->in[POS_CODE], POS_AUTH - POS_CODE); 309 MD5Update(&ctx, zeroes, LEN_AUTH); 310 MD5Update(&ctx, &h->in[POS_ATTRS], len - POS_ATTRS); 311 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 312 MD5Final(md5, &ctx); 313 if (memcmp(&h->in[POS_AUTH], md5, sizeof md5) != 0) 314 return (0); 315 } 316 317 #ifdef WITH_SSL 318 /* Search and verify the Message-Authenticator */ 319 pos = POS_ATTRS; 320 hctx = HMAC_CTX_new(); 321 while (pos < len - 2) { 322 alen = h->in[pos + 1]; 323 if (alen < 2) { 324 HMAC_CTX_free(hctx); 325 return (0); 326 } 327 if (h->in[pos] == RAD_MESSAGE_AUTHENTIC) { 328 if (len - pos < MD5_DIGEST_LENGTH + 2) { 329 HMAC_CTX_free(hctx); 330 return (0); 331 } 332 if (alen < MD5_DIGEST_LENGTH + 2) { 333 HMAC_CTX_free(hctx); 334 return (0); 335 } 336 memcpy(resp, h->in, MSGSIZE); 337 /* zero fill the Request-Authenticator */ 338 if (h->in[POS_CODE] != RAD_ACCESS_REQUEST) 339 memset(&resp[POS_AUTH], 0, LEN_AUTH); 340 /* zero fill the Message-Authenticator */ 341 memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH); 342 343 HMAC_Init_ex(hctx, srvp->secret, 344 strlen(srvp->secret), EVP_md5(), NULL); 345 HMAC_Update(hctx, resp, h->in_len); 346 HMAC_Final(hctx, md, &md_len); 347 HMAC_CTX_reset(hctx); 348 if (memcmp(md, &h->in[pos + 2], 349 MD5_DIGEST_LENGTH) != 0) { 350 HMAC_CTX_free(hctx); 351 return (0); 352 } 353 break; 354 } 355 pos += alen; 356 } 357 HMAC_CTX_free(hctx); 358 #endif 359 return (1); 360 } 361 362 static int 363 put_password_attr(struct rad_handle *h, int type, const void *value, size_t len) 364 { 365 int padded_len; 366 int pad_len; 367 368 if (h->pass_pos != 0) { 369 generr(h, "Multiple User-Password attributes specified"); 370 return -1; 371 } 372 if (len > PASSSIZE) 373 len = PASSSIZE; 374 padded_len = len == 0 ? 16 : (len+15) & ~0xf; 375 pad_len = padded_len - len; 376 377 /* 378 * Put in a place-holder attribute containing all zeros, and 379 * remember where it is so we can fill it in later. 380 */ 381 clear_password(h); 382 put_raw_attr(h, type, h->pass, padded_len); 383 h->pass_pos = h->out_len - padded_len; 384 385 /* Save the cleartext password, padded as necessary */ 386 memcpy(h->pass, value, len); 387 h->pass_len = len; 388 memset(h->pass + len, 0, pad_len); 389 return 0; 390 } 391 392 static int 393 put_raw_attr(struct rad_handle *h, int type, const void *value, size_t len) 394 { 395 if (len > 253) { 396 generr(h, "Attribute too long"); 397 return -1; 398 } 399 if (h->out_len + 2 + len > MSGSIZE) { 400 generr(h, "Maximum message length exceeded"); 401 return -1; 402 } 403 h->out[h->out_len++] = type; 404 h->out[h->out_len++] = len + 2; 405 memcpy(&h->out[h->out_len], value, len); 406 h->out_len += len; 407 return 0; 408 } 409 410 int 411 rad_add_server(struct rad_handle *h, const char *host, int port, 412 const char *secret, int timeout, int tries) 413 { 414 struct in_addr bindto; 415 bindto.s_addr = INADDR_ANY; 416 417 return rad_add_server_ex(h, host, port, secret, timeout, tries, 418 DEAD_TIME, &bindto); 419 } 420 421 int 422 rad_add_server_ex(struct rad_handle *h, const char *host, int port, 423 const char *secret, int timeout, int tries, int dead_time, 424 struct in_addr *bindto) 425 { 426 struct rad_server *srvp; 427 428 if (h->num_servers >= MAXSERVERS) { 429 generr(h, "Too many RADIUS servers specified"); 430 return -1; 431 } 432 srvp = &h->servers[h->num_servers]; 433 434 memset(&srvp->addr, 0, sizeof srvp->addr); 435 srvp->addr.sin_len = sizeof srvp->addr; 436 srvp->addr.sin_family = AF_INET; 437 if (!inet_aton(host, &srvp->addr.sin_addr)) { 438 struct hostent *hent; 439 440 if ((hent = gethostbyname(host)) == NULL) { 441 generr(h, "%s: host not found", host); 442 return -1; 443 } 444 memcpy(&srvp->addr.sin_addr, hent->h_addr, 445 sizeof srvp->addr.sin_addr); 446 } 447 if (port != 0) 448 srvp->addr.sin_port = htons((u_short)port); 449 else { 450 struct servent *sent; 451 452 if (h->type == RADIUS_AUTH) 453 srvp->addr.sin_port = 454 (sent = getservbyname("radius", "udp")) != NULL ? 455 sent->s_port : htons(RADIUS_PORT); 456 else 457 srvp->addr.sin_port = 458 (sent = getservbyname("radacct", "udp")) != NULL ? 459 sent->s_port : htons(RADACCT_PORT); 460 } 461 if ((srvp->secret = strdup(secret)) == NULL) { 462 generr(h, "Out of memory"); 463 return -1; 464 } 465 srvp->timeout = timeout; 466 srvp->max_tries = tries; 467 srvp->num_tries = 0; 468 srvp->is_dead = 0; 469 srvp->dead_time = dead_time; 470 srvp->next_probe = 0; 471 srvp->bindto = bindto->s_addr; 472 h->num_servers++; 473 return 0; 474 } 475 476 void 477 rad_close(struct rad_handle *h) 478 { 479 int srv; 480 481 if (h->fd != -1) 482 close(h->fd); 483 for (srv = 0; srv < h->num_servers; srv++) { 484 memset(h->servers[srv].secret, 0, 485 strlen(h->servers[srv].secret)); 486 free(h->servers[srv].secret); 487 } 488 clear_password(h); 489 free(h); 490 } 491 492 void 493 rad_bind_to(struct rad_handle *h, in_addr_t addr) 494 { 495 496 h->bindto = addr; 497 } 498 499 int 500 rad_config(struct rad_handle *h, const char *path) 501 { 502 FILE *fp; 503 char buf[MAXCONFLINE]; 504 int linenum; 505 int retval; 506 507 if (path == NULL) 508 path = PATH_RADIUS_CONF; 509 if ((fp = fopen(path, "r")) == NULL) { 510 generr(h, "Cannot open \"%s\": %s", path, strerror(errno)); 511 return -1; 512 } 513 retval = 0; 514 linenum = 0; 515 while (fgets(buf, sizeof buf, fp) != NULL) { 516 int len; 517 char *fields[MAX_FIELDS]; 518 int nfields; 519 char msg[ERRSIZE]; 520 char *type; 521 char *host, *res; 522 char *port_str; 523 char *secret; 524 char *timeout_str; 525 char *maxtries_str; 526 char *dead_time_str; 527 char *bindto_str; 528 char *end; 529 char *wanttype; 530 unsigned long timeout; 531 unsigned long maxtries; 532 unsigned long dead_time; 533 int port; 534 struct in_addr bindto; 535 int i; 536 537 linenum++; 538 len = strlen(buf); 539 /* We know len > 0, else fgets would have returned NULL. */ 540 if (buf[len - 1] != '\n') { 541 if (len == sizeof buf - 1) 542 generr(h, "%s:%d: line too long", path, 543 linenum); 544 else 545 generr(h, "%s:%d: missing newline", path, 546 linenum); 547 retval = -1; 548 break; 549 } 550 buf[len - 1] = '\0'; 551 552 /* Extract the fields from the line. */ 553 nfields = split(buf, fields, MAX_FIELDS, msg, sizeof msg); 554 if (nfields == -1) { 555 generr(h, "%s:%d: %s", path, linenum, msg); 556 retval = -1; 557 break; 558 } 559 if (nfields == 0) 560 continue; 561 /* 562 * The first field should contain "auth" or "acct" for 563 * authentication or accounting, respectively. But older 564 * versions of the file didn't have that field. Default 565 * it to "auth" for backward compatibility. 566 */ 567 if (strcmp(fields[0], "auth") != 0 && 568 strcmp(fields[0], "acct") != 0) { 569 if (nfields >= MAX_FIELDS) { 570 generr(h, "%s:%d: invalid service type", path, 571 linenum); 572 retval = -1; 573 break; 574 } 575 nfields++; 576 for (i = nfields; --i > 0; ) 577 fields[i] = fields[i - 1]; 578 fields[0] = "auth"; 579 } 580 if (nfields < 3) { 581 generr(h, "%s:%d: missing shared secret", path, 582 linenum); 583 retval = -1; 584 break; 585 } 586 type = fields[0]; 587 host = fields[1]; 588 secret = fields[2]; 589 timeout_str = fields[3]; 590 maxtries_str = fields[4]; 591 dead_time_str = fields[5]; 592 bindto_str = fields[6]; 593 594 /* Ignore the line if it is for the wrong service type. */ 595 wanttype = h->type == RADIUS_AUTH ? "auth" : "acct"; 596 if (strcmp(type, wanttype) != 0) 597 continue; 598 599 /* Parse and validate the fields. */ 600 res = host; 601 host = strsep(&res, ":"); 602 port_str = strsep(&res, ":"); 603 if (port_str != NULL) { 604 port = strtoul(port_str, &end, 10); 605 if (*end != '\0') { 606 generr(h, "%s:%d: invalid port", path, 607 linenum); 608 retval = -1; 609 break; 610 } 611 } else 612 port = 0; 613 if (timeout_str != NULL) { 614 timeout = strtoul(timeout_str, &end, 10); 615 if (*end != '\0') { 616 generr(h, "%s:%d: invalid timeout", path, 617 linenum); 618 retval = -1; 619 break; 620 } 621 } else 622 timeout = TIMEOUT; 623 if (maxtries_str != NULL) { 624 maxtries = strtoul(maxtries_str, &end, 10); 625 if (*end != '\0') { 626 generr(h, "%s:%d: invalid maxtries", path, 627 linenum); 628 retval = -1; 629 break; 630 } 631 } else 632 maxtries = MAXTRIES; 633 634 if (dead_time_str != NULL) { 635 dead_time = strtoul(dead_time_str, &end, 10); 636 if (*end != '\0') { 637 generr(h, "%s:%d: invalid dead_time", path, 638 linenum); 639 retval = -1; 640 break; 641 } 642 } else 643 dead_time = DEAD_TIME; 644 645 if (bindto_str != NULL) { 646 bindto.s_addr = inet_addr(bindto_str); 647 if (bindto.s_addr == INADDR_NONE) { 648 generr(h, "%s:%d: invalid bindto", path, 649 linenum); 650 retval = -1; 651 break; 652 } 653 } else 654 bindto.s_addr = INADDR_ANY; 655 656 if (rad_add_server_ex(h, host, port, secret, timeout, maxtries, 657 dead_time, &bindto) == -1) { 658 strcpy(msg, h->errmsg); 659 generr(h, "%s:%d: %s", path, linenum, msg); 660 retval = -1; 661 break; 662 } 663 } 664 /* Clear out the buffer to wipe a possible copy of a shared secret */ 665 memset(buf, 0, sizeof buf); 666 fclose(fp); 667 return retval; 668 } 669 670 /* 671 * rad_init_send_request() must have previously been called. 672 * Returns: 673 * 0 The application should select on *fd with a timeout of tv before 674 * calling rad_continue_send_request again. 675 * < 0 Failure 676 * > 0 Success 677 */ 678 int 679 rad_continue_send_request(struct rad_handle *h, int selected, int *fd, 680 struct timeval *tv) 681 { 682 int n, cur_srv; 683 time_t now; 684 struct sockaddr_in sin; 685 686 if (h->type == RADIUS_SERVER) { 687 generr(h, "denied function call"); 688 return (-1); 689 } 690 if (selected) { 691 struct sockaddr_in from; 692 socklen_t fromlen; 693 694 fromlen = sizeof from; 695 h->in_len = recvfrom(h->fd, h->in, 696 MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen); 697 if (h->in_len == -1) { 698 generr(h, "recvfrom: %s", strerror(errno)); 699 return -1; 700 } 701 if (is_valid_response(h, h->srv, &from)) { 702 h->in_len = h->in[POS_LENGTH] << 8 | 703 h->in[POS_LENGTH+1]; 704 h->in_pos = POS_ATTRS; 705 return h->in[POS_CODE]; 706 } 707 } 708 709 /* 710 * Scan round-robin to the next server that has some 711 * tries left. There is guaranteed to be one, or we 712 * would have exited this loop by now. 713 */ 714 cur_srv = h->srv; 715 now = time(NULL); 716 if (h->servers[h->srv].num_tries >= h->servers[h->srv].max_tries) { 717 /* Set next probe time for this server */ 718 if (h->servers[h->srv].dead_time) { 719 h->servers[h->srv].is_dead = 1; 720 h->servers[h->srv].next_probe = now + 721 h->servers[h->srv].dead_time; 722 } 723 do { 724 h->srv++; 725 if (h->srv >= h->num_servers) 726 h->srv = 0; 727 if (h->servers[h->srv].is_dead == 0) 728 break; 729 if (h->servers[h->srv].dead_time && 730 h->servers[h->srv].next_probe <= now) { 731 h->servers[h->srv].is_dead = 0; 732 h->servers[h->srv].num_tries = 0; 733 break; 734 } 735 } while (h->srv != cur_srv); 736 737 if (h->srv == cur_srv) { 738 generr(h, "No valid RADIUS responses received"); 739 return (-1); 740 } 741 } 742 743 /* Rebind */ 744 if (h->bindto != h->servers[h->srv].bindto) { 745 h->bindto = h->servers[h->srv].bindto; 746 close(h->fd); 747 if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) { 748 generr(h, "Cannot create socket: %s", strerror(errno)); 749 return -1; 750 } 751 memset(&sin, 0, sizeof sin); 752 sin.sin_len = sizeof sin; 753 sin.sin_family = AF_INET; 754 sin.sin_addr.s_addr = h->bindto; 755 sin.sin_port = 0; 756 if (bind(h->fd, (const struct sockaddr *)&sin, 757 sizeof sin) == -1) { 758 generr(h, "bind: %s", strerror(errno)); 759 close(h->fd); 760 h->fd = -1; 761 return (-1); 762 } 763 } 764 765 if (h->out[POS_CODE] == RAD_ACCESS_REQUEST) { 766 /* Insert the scrambled password into the request */ 767 if (h->pass_pos != 0) 768 insert_scrambled_password(h, h->srv); 769 } 770 insert_message_authenticator(h, 0); 771 772 if (h->out[POS_CODE] != RAD_ACCESS_REQUEST) { 773 /* Insert the request authenticator into the request */ 774 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 775 insert_request_authenticator(h, 0); 776 } 777 778 /* Send the request */ 779 n = sendto(h->fd, h->out, h->out_len, 0, 780 (const struct sockaddr *)&h->servers[h->srv].addr, 781 sizeof h->servers[h->srv].addr); 782 if (n != h->out_len) 783 tv->tv_sec = 1; /* Do not wait full timeout if send failed. */ 784 else 785 tv->tv_sec = h->servers[h->srv].timeout; 786 h->servers[h->srv].num_tries++; 787 tv->tv_usec = 0; 788 *fd = h->fd; 789 790 return 0; 791 } 792 793 int 794 rad_receive_request(struct rad_handle *h) 795 { 796 struct sockaddr_in from; 797 socklen_t fromlen; 798 int n; 799 800 if (h->type != RADIUS_SERVER) { 801 generr(h, "denied function call"); 802 return (-1); 803 } 804 h->srv = -1; 805 fromlen = sizeof(from); 806 h->in_len = recvfrom(h->fd, h->in, 807 MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen); 808 if (h->in_len == -1) { 809 generr(h, "recvfrom: %s", strerror(errno)); 810 return (-1); 811 } 812 for (n = 0; n < h->num_servers; n++) { 813 if (h->servers[n].addr.sin_addr.s_addr == from.sin_addr.s_addr) { 814 h->servers[n].addr.sin_port = from.sin_port; 815 h->srv = n; 816 break; 817 } 818 } 819 if (h->srv == -1) 820 return (-2); 821 if (is_valid_request(h)) { 822 h->in_len = h->in[POS_LENGTH] << 8 | 823 h->in[POS_LENGTH+1]; 824 h->in_pos = POS_ATTRS; 825 return (h->in[POS_CODE]); 826 } 827 return (-3); 828 } 829 830 int 831 rad_send_response(struct rad_handle *h) 832 { 833 int n; 834 835 if (h->type != RADIUS_SERVER) { 836 generr(h, "denied function call"); 837 return (-1); 838 } 839 /* Fill in the length field in the message */ 840 h->out[POS_LENGTH] = h->out_len >> 8; 841 h->out[POS_LENGTH+1] = h->out_len; 842 843 insert_message_authenticator(h, 844 (h->in[POS_CODE] == RAD_ACCESS_REQUEST) ? 1 : 0); 845 insert_request_authenticator(h, 1); 846 847 /* Send the request */ 848 n = sendto(h->fd, h->out, h->out_len, 0, 849 (const struct sockaddr *)&h->servers[h->srv].addr, 850 sizeof h->servers[h->srv].addr); 851 if (n != h->out_len) { 852 if (n == -1) 853 generr(h, "sendto: %s", strerror(errno)); 854 else 855 generr(h, "sendto: short write"); 856 return -1; 857 } 858 859 return 0; 860 } 861 862 int 863 rad_create_request(struct rad_handle *h, int code) 864 { 865 int i; 866 867 if (h->type == RADIUS_SERVER) { 868 generr(h, "denied function call"); 869 return (-1); 870 } 871 if (h->num_servers == 0) { 872 generr(h, "No RADIUS servers specified"); 873 return (-1); 874 } 875 h->out[POS_CODE] = code; 876 h->out[POS_IDENT] = ++h->ident; 877 if (code == RAD_ACCESS_REQUEST) { 878 /* Create a random authenticator */ 879 for (i = 0; i < LEN_AUTH; i += 2) { 880 uint32_t r; 881 r = arc4random(); 882 h->out[POS_AUTH+i] = (u_char)r; 883 h->out[POS_AUTH+i+1] = (u_char)(r >> 8); 884 } 885 } else 886 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 887 h->out_len = POS_ATTRS; 888 clear_password(h); 889 h->authentic_pos = 0; 890 h->out_created = 1; 891 return 0; 892 } 893 894 int 895 rad_create_response(struct rad_handle *h, int code) 896 { 897 898 if (h->type != RADIUS_SERVER) { 899 generr(h, "denied function call"); 900 return (-1); 901 } 902 h->out[POS_CODE] = code; 903 h->out[POS_IDENT] = h->in[POS_IDENT]; 904 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 905 h->out_len = POS_ATTRS; 906 clear_password(h); 907 h->authentic_pos = 0; 908 h->out_created = 1; 909 return 0; 910 } 911 912 struct in_addr 913 rad_cvt_addr(const void *data) 914 { 915 struct in_addr value; 916 917 memcpy(&value.s_addr, data, sizeof value.s_addr); 918 return value; 919 } 920 921 struct in6_addr 922 rad_cvt_addr6(const void *data) 923 { 924 struct in6_addr value; 925 926 memcpy(&value.s6_addr, data, sizeof value.s6_addr); 927 return value; 928 } 929 930 u_int32_t 931 rad_cvt_int(const void *data) 932 { 933 u_int32_t value; 934 935 memcpy(&value, data, sizeof value); 936 return ntohl(value); 937 } 938 939 char * 940 rad_cvt_string(const void *data, size_t len) 941 { 942 char *s; 943 944 s = malloc(len + 1); 945 if (s != NULL) { 946 memcpy(s, data, len); 947 s[len] = '\0'; 948 } 949 return s; 950 } 951 952 /* 953 * Returns the attribute type. If none are left, returns 0. On failure, 954 * returns -1. 955 */ 956 int 957 rad_get_attr(struct rad_handle *h, const void **value, size_t *lenp) 958 { 959 int len, type; 960 961 if (h->in_pos >= h->in_len) 962 return 0; 963 if (h->in_pos + 2 > h->in_len) { 964 generr(h, "Malformed attribute in response"); 965 return -1; 966 } 967 type = h->in[h->in_pos++]; 968 len = h->in[h->in_pos++]; 969 if (len < 2) { 970 generr(h, "Malformed attribute in response"); 971 return -1; 972 } 973 len -= 2; 974 if (h->in_pos + len > h->in_len) { 975 generr(h, "Malformed attribute in response"); 976 return -1; 977 } 978 *lenp = len; 979 *value = &h->in[h->in_pos]; 980 h->in_pos += len; 981 return type; 982 } 983 984 /* 985 * Returns -1 on error, 0 to indicate no event and >0 for success 986 */ 987 int 988 rad_init_send_request(struct rad_handle *h, int *fd, struct timeval *tv) 989 { 990 int srv; 991 time_t now; 992 struct sockaddr_in sin; 993 994 if (h->type == RADIUS_SERVER) { 995 generr(h, "denied function call"); 996 return (-1); 997 } 998 /* Make sure we have a socket to use */ 999 if (h->fd == -1) { 1000 if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) { 1001 generr(h, "Cannot create socket: %s", strerror(errno)); 1002 return -1; 1003 } 1004 memset(&sin, 0, sizeof sin); 1005 sin.sin_len = sizeof sin; 1006 sin.sin_family = AF_INET; 1007 sin.sin_addr.s_addr = h->bindto; 1008 sin.sin_port = htons(0); 1009 if (bind(h->fd, (const struct sockaddr *)&sin, 1010 sizeof sin) == -1) { 1011 generr(h, "bind: %s", strerror(errno)); 1012 close(h->fd); 1013 h->fd = -1; 1014 return -1; 1015 } 1016 } 1017 1018 if (h->out[POS_CODE] != RAD_ACCESS_REQUEST) { 1019 /* Make sure no password given */ 1020 if (h->pass_pos || h->chap_pass) { 1021 generr(h, "User or Chap Password" 1022 " in accounting request"); 1023 return -1; 1024 } 1025 } else { 1026 if (h->eap_msg == 0) { 1027 /* Make sure the user gave us a password */ 1028 if (h->pass_pos == 0 && !h->chap_pass) { 1029 generr(h, "No User or Chap Password" 1030 " attributes given"); 1031 return -1; 1032 } 1033 if (h->pass_pos != 0 && h->chap_pass) { 1034 generr(h, "Both User and Chap Password" 1035 " attributes given"); 1036 return -1; 1037 } 1038 } 1039 } 1040 1041 /* Fill in the length field in the message */ 1042 h->out[POS_LENGTH] = h->out_len >> 8; 1043 h->out[POS_LENGTH+1] = h->out_len; 1044 1045 h->srv = 0; 1046 now = time(NULL); 1047 for (srv = 0; srv < h->num_servers; srv++) 1048 h->servers[srv].num_tries = 0; 1049 /* Find a first good server. */ 1050 for (srv = 0; srv < h->num_servers; srv++) { 1051 if (h->servers[srv].is_dead == 0) 1052 break; 1053 if (h->servers[srv].dead_time && 1054 h->servers[srv].next_probe <= now) { 1055 h->servers[srv].is_dead = 0; 1056 break; 1057 } 1058 h->srv++; 1059 } 1060 1061 /* If all servers was dead on the last probe, try from beginning */ 1062 if (h->srv == h->num_servers) { 1063 for (srv = 0; srv < h->num_servers; srv++) { 1064 h->servers[srv].is_dead = 0; 1065 h->servers[srv].next_probe = 0; 1066 } 1067 h->srv = 0; 1068 } 1069 1070 return rad_continue_send_request(h, 0, fd, tv); 1071 } 1072 1073 /* 1074 * Create and initialize a rad_handle structure, and return it to the 1075 * caller. Can fail only if the necessary memory cannot be allocated. 1076 * In that case, it returns NULL. 1077 */ 1078 struct rad_handle * 1079 rad_auth_open(void) 1080 { 1081 struct rad_handle *h; 1082 1083 h = (struct rad_handle *)malloc(sizeof(struct rad_handle)); 1084 if (h != NULL) { 1085 h->fd = -1; 1086 h->num_servers = 0; 1087 h->ident = arc4random(); 1088 h->errmsg[0] = '\0'; 1089 memset(h->pass, 0, sizeof h->pass); 1090 h->pass_len = 0; 1091 h->pass_pos = 0; 1092 h->chap_pass = 0; 1093 h->authentic_pos = 0; 1094 h->type = RADIUS_AUTH; 1095 h->out_created = 0; 1096 h->eap_msg = 0; 1097 h->bindto = INADDR_ANY; 1098 } 1099 return h; 1100 } 1101 1102 struct rad_handle * 1103 rad_acct_open(void) 1104 { 1105 struct rad_handle *h; 1106 1107 h = rad_open(); 1108 if (h != NULL) 1109 h->type = RADIUS_ACCT; 1110 return h; 1111 } 1112 1113 struct rad_handle * 1114 rad_server_open(int fd) 1115 { 1116 struct rad_handle *h; 1117 1118 h = rad_open(); 1119 if (h != NULL) { 1120 h->type = RADIUS_SERVER; 1121 h->fd = fd; 1122 } 1123 return h; 1124 } 1125 1126 struct rad_handle * 1127 rad_open(void) 1128 { 1129 return rad_auth_open(); 1130 } 1131 1132 int 1133 rad_put_addr(struct rad_handle *h, int type, struct in_addr addr) 1134 { 1135 return rad_put_attr(h, type, &addr.s_addr, sizeof addr.s_addr); 1136 } 1137 1138 int 1139 rad_put_addr6(struct rad_handle *h, int type, struct in6_addr addr) 1140 { 1141 1142 return rad_put_attr(h, type, &addr.s6_addr, sizeof addr.s6_addr); 1143 } 1144 1145 int 1146 rad_put_attr(struct rad_handle *h, int type, const void *value, size_t len) 1147 { 1148 int result; 1149 1150 if (!h->out_created) { 1151 generr(h, "Please call rad_create_request()" 1152 " before putting attributes"); 1153 return -1; 1154 } 1155 1156 if (h->out[POS_CODE] == RAD_ACCOUNTING_REQUEST) { 1157 if (type == RAD_EAP_MESSAGE) { 1158 generr(h, "EAP-Message attribute is not valid" 1159 " in accounting requests"); 1160 return -1; 1161 } 1162 } 1163 1164 /* 1165 * When proxying EAP Messages, the Message Authenticator 1166 * MUST be present; see RFC 3579. 1167 */ 1168 if (type == RAD_EAP_MESSAGE) { 1169 if (rad_put_message_authentic(h) == -1) 1170 return -1; 1171 } 1172 1173 if (type == RAD_USER_PASSWORD) { 1174 result = put_password_attr(h, type, value, len); 1175 } else if (type == RAD_MESSAGE_AUTHENTIC) { 1176 result = rad_put_message_authentic(h); 1177 } else { 1178 result = put_raw_attr(h, type, value, len); 1179 if (result == 0) { 1180 if (type == RAD_CHAP_PASSWORD) 1181 h->chap_pass = 1; 1182 else if (type == RAD_EAP_MESSAGE) 1183 h->eap_msg = 1; 1184 } 1185 } 1186 1187 return result; 1188 } 1189 1190 int 1191 rad_put_int(struct rad_handle *h, int type, u_int32_t value) 1192 { 1193 u_int32_t nvalue; 1194 1195 nvalue = htonl(value); 1196 return rad_put_attr(h, type, &nvalue, sizeof nvalue); 1197 } 1198 1199 int 1200 rad_put_string(struct rad_handle *h, int type, const char *str) 1201 { 1202 return rad_put_attr(h, type, str, strlen(str)); 1203 } 1204 1205 int 1206 rad_put_message_authentic(struct rad_handle *h) 1207 { 1208 #ifdef WITH_SSL 1209 u_char md_zero[MD5_DIGEST_LENGTH]; 1210 1211 if (h->out[POS_CODE] == RAD_ACCOUNTING_REQUEST) { 1212 generr(h, "Message-Authenticator is not valid" 1213 " in accounting requests"); 1214 return -1; 1215 } 1216 1217 if (h->authentic_pos == 0) { 1218 h->authentic_pos = h->out_len; 1219 memset(md_zero, 0, sizeof(md_zero)); 1220 return (put_raw_attr(h, RAD_MESSAGE_AUTHENTIC, md_zero, 1221 sizeof(md_zero))); 1222 } 1223 return 0; 1224 #else 1225 generr(h, "Message Authenticator not supported," 1226 " please recompile libradius with SSL support"); 1227 return -1; 1228 #endif 1229 } 1230 1231 /* 1232 * Returns the response type code on success, or -1 on failure. 1233 */ 1234 int 1235 rad_send_request(struct rad_handle *h) 1236 { 1237 struct timeval timelimit; 1238 struct timeval tv; 1239 int fd; 1240 int n; 1241 1242 n = rad_init_send_request(h, &fd, &tv); 1243 1244 if (n != 0) 1245 return n; 1246 1247 gettimeofday(&timelimit, NULL); 1248 timeradd(&tv, &timelimit, &timelimit); 1249 1250 for ( ; ; ) { 1251 fd_set readfds; 1252 1253 FD_ZERO(&readfds); 1254 FD_SET(fd, &readfds); 1255 1256 n = select(fd + 1, &readfds, NULL, NULL, &tv); 1257 1258 if (n == -1) { 1259 generr(h, "select: %s", strerror(errno)); 1260 return -1; 1261 } 1262 1263 if (!FD_ISSET(fd, &readfds)) { 1264 /* Compute a new timeout */ 1265 gettimeofday(&tv, NULL); 1266 timersub(&timelimit, &tv, &tv); 1267 if (tv.tv_sec > 0 || (tv.tv_sec == 0 && tv.tv_usec > 0)) 1268 /* Continue the select */ 1269 continue; 1270 } 1271 1272 n = rad_continue_send_request(h, n, &fd, &tv); 1273 1274 if (n != 0) 1275 return n; 1276 1277 gettimeofday(&timelimit, NULL); 1278 timeradd(&tv, &timelimit, &timelimit); 1279 } 1280 } 1281 1282 const char * 1283 rad_strerror(struct rad_handle *h) 1284 { 1285 return h->errmsg; 1286 } 1287 1288 /* 1289 * Destructively split a string into fields separated by white space. 1290 * `#' at the beginning of a field begins a comment that extends to the 1291 * end of the string. Fields may be quoted with `"'. Inside quoted 1292 * strings, the backslash escapes `\"' and `\\' are honored. 1293 * 1294 * Pointers to up to the first maxfields fields are stored in the fields 1295 * array. Missing fields get NULL pointers. 1296 * 1297 * The return value is the actual number of fields parsed, and is always 1298 * <= maxfields. 1299 * 1300 * On a syntax error, places a message in the msg string, and returns -1. 1301 */ 1302 static int 1303 split(char *str, char *fields[], int maxfields, char *msg, size_t msglen) 1304 { 1305 char *p; 1306 int i; 1307 static const char ws[] = " \t"; 1308 1309 for (i = 0; i < maxfields; i++) 1310 fields[i] = NULL; 1311 p = str; 1312 i = 0; 1313 while (*p != '\0') { 1314 p += strspn(p, ws); 1315 if (*p == '#' || *p == '\0') 1316 break; 1317 if (i >= maxfields) { 1318 snprintf(msg, msglen, "line has too many fields"); 1319 return -1; 1320 } 1321 if (*p == '"') { 1322 char *dst; 1323 1324 dst = ++p; 1325 fields[i] = dst; 1326 while (*p != '"') { 1327 if (*p == '\\') { 1328 p++; 1329 if (*p != '"' && *p != '\\' && 1330 *p != '\0') { 1331 snprintf(msg, msglen, 1332 "invalid `\\' escape"); 1333 return -1; 1334 } 1335 } 1336 if (*p == '\0') { 1337 snprintf(msg, msglen, 1338 "unterminated quoted string"); 1339 return -1; 1340 } 1341 *dst++ = *p++; 1342 } 1343 *dst = '\0'; 1344 p++; 1345 if (*fields[i] == '\0') { 1346 snprintf(msg, msglen, 1347 "empty quoted string not permitted"); 1348 return -1; 1349 } 1350 if (*p != '\0' && strspn(p, ws) == 0) { 1351 snprintf(msg, msglen, "quoted string not" 1352 " followed by white space"); 1353 return -1; 1354 } 1355 } else { 1356 fields[i] = p; 1357 p += strcspn(p, ws); 1358 if (*p != '\0') 1359 *p++ = '\0'; 1360 } 1361 i++; 1362 } 1363 return i; 1364 } 1365 1366 int 1367 rad_get_vendor_attr(u_int32_t *vendor, const void **data, size_t *len) 1368 { 1369 struct vendor_attribute *attr; 1370 1371 attr = (struct vendor_attribute *)*data; 1372 *vendor = ntohl(attr->vendor_value); 1373 *data = attr->attrib_data; 1374 *len = attr->attrib_len - 2; 1375 1376 return (attr->attrib_type); 1377 } 1378 1379 int 1380 rad_put_vendor_addr(struct rad_handle *h, int vendor, int type, 1381 struct in_addr addr) 1382 { 1383 return (rad_put_vendor_attr(h, vendor, type, &addr.s_addr, 1384 sizeof addr.s_addr)); 1385 } 1386 1387 int 1388 rad_put_vendor_addr6(struct rad_handle *h, int vendor, int type, 1389 struct in6_addr addr) 1390 { 1391 1392 return (rad_put_vendor_attr(h, vendor, type, &addr.s6_addr, 1393 sizeof addr.s6_addr)); 1394 } 1395 1396 int 1397 rad_put_vendor_attr(struct rad_handle *h, int vendor, int type, 1398 const void *value, size_t len) 1399 { 1400 struct vendor_attribute *attr; 1401 int res; 1402 1403 if (!h->out_created) { 1404 generr(h, "Please call rad_create_request()" 1405 " before putting attributes"); 1406 return -1; 1407 } 1408 1409 if ((attr = malloc(len + 6)) == NULL) { 1410 generr(h, "malloc failure (%zu bytes)", len + 6); 1411 return -1; 1412 } 1413 1414 attr->vendor_value = htonl(vendor); 1415 attr->attrib_type = type; 1416 attr->attrib_len = len + 2; 1417 memcpy(attr->attrib_data, value, len); 1418 1419 res = put_raw_attr(h, RAD_VENDOR_SPECIFIC, attr, len + 6); 1420 free(attr); 1421 if (res == 0 && vendor == RAD_VENDOR_MICROSOFT 1422 && (type == RAD_MICROSOFT_MS_CHAP_RESPONSE 1423 || type == RAD_MICROSOFT_MS_CHAP2_RESPONSE)) { 1424 h->chap_pass = 1; 1425 } 1426 return (res); 1427 } 1428 1429 int 1430 rad_put_vendor_int(struct rad_handle *h, int vendor, int type, u_int32_t i) 1431 { 1432 u_int32_t value; 1433 1434 value = htonl(i); 1435 return (rad_put_vendor_attr(h, vendor, type, &value, sizeof value)); 1436 } 1437 1438 int 1439 rad_put_vendor_string(struct rad_handle *h, int vendor, int type, 1440 const char *str) 1441 { 1442 return (rad_put_vendor_attr(h, vendor, type, str, strlen(str))); 1443 } 1444 1445 ssize_t 1446 rad_request_authenticator(struct rad_handle *h, char *buf, size_t len) 1447 { 1448 if (len < LEN_AUTH) 1449 return (-1); 1450 memcpy(buf, h->out + POS_AUTH, LEN_AUTH); 1451 if (len > LEN_AUTH) 1452 buf[LEN_AUTH] = '\0'; 1453 return (LEN_AUTH); 1454 } 1455 1456 u_char * 1457 rad_demangle(struct rad_handle *h, const void *mangled, size_t mlen) 1458 { 1459 char R[LEN_AUTH]; 1460 const char *S; 1461 int i, Ppos; 1462 MD5_CTX Context; 1463 u_char b[MD5_DIGEST_LENGTH], *C, *demangled; 1464 1465 if ((mlen % 16 != 0) || mlen > 128) { 1466 generr(h, "Cannot interpret mangled data of length %lu", 1467 (u_long)mlen); 1468 return NULL; 1469 } 1470 1471 C = (u_char *)mangled; 1472 1473 /* We need the shared secret as Salt */ 1474 S = rad_server_secret(h); 1475 1476 /* We need the request authenticator */ 1477 if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) { 1478 generr(h, "Cannot obtain the RADIUS request authenticator"); 1479 return NULL; 1480 } 1481 1482 demangled = malloc(mlen); 1483 if (!demangled) 1484 return NULL; 1485 1486 MD5Init(&Context); 1487 MD5Update(&Context, S, strlen(S)); 1488 MD5Update(&Context, R, LEN_AUTH); 1489 MD5Final(b, &Context); 1490 Ppos = 0; 1491 while (mlen) { 1492 1493 mlen -= 16; 1494 for (i = 0; i < 16; i++) 1495 demangled[Ppos++] = C[i] ^ b[i]; 1496 1497 if (mlen) { 1498 MD5Init(&Context); 1499 MD5Update(&Context, S, strlen(S)); 1500 MD5Update(&Context, C, 16); 1501 MD5Final(b, &Context); 1502 } 1503 1504 C += 16; 1505 } 1506 1507 return demangled; 1508 } 1509 1510 u_char * 1511 rad_demangle_mppe_key(struct rad_handle *h, const void *mangled, 1512 size_t mlen, size_t *len) 1513 { 1514 char R[LEN_AUTH]; /* variable names as per rfc2548 */ 1515 const char *S; 1516 u_char b[MD5_DIGEST_LENGTH], *demangled; 1517 const u_char *A, *C; 1518 MD5_CTX Context; 1519 int Slen, i, Clen, Ppos; 1520 u_char *P; 1521 1522 if (mlen % 16 != SALT_LEN) { 1523 generr(h, "Cannot interpret mangled data of length %lu", 1524 (u_long)mlen); 1525 return NULL; 1526 } 1527 1528 /* We need the RADIUS Request-Authenticator */ 1529 if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) { 1530 generr(h, "Cannot obtain the RADIUS request authenticator"); 1531 return NULL; 1532 } 1533 1534 A = (const u_char *)mangled; /* Salt comes first */ 1535 C = (const u_char *)mangled + SALT_LEN; /* Then the ciphertext */ 1536 Clen = mlen - SALT_LEN; 1537 S = rad_server_secret(h); /* We need the RADIUS secret */ 1538 Slen = strlen(S); 1539 P = alloca(Clen); /* We derive our plaintext */ 1540 1541 MD5Init(&Context); 1542 MD5Update(&Context, S, Slen); 1543 MD5Update(&Context, R, LEN_AUTH); 1544 MD5Update(&Context, A, SALT_LEN); 1545 MD5Final(b, &Context); 1546 Ppos = 0; 1547 1548 while (Clen) { 1549 Clen -= 16; 1550 1551 for (i = 0; i < 16; i++) 1552 P[Ppos++] = C[i] ^ b[i]; 1553 1554 if (Clen) { 1555 MD5Init(&Context); 1556 MD5Update(&Context, S, Slen); 1557 MD5Update(&Context, C, 16); 1558 MD5Final(b, &Context); 1559 } 1560 1561 C += 16; 1562 } 1563 1564 /* 1565 * The resulting plain text consists of a one-byte length, the text and 1566 * maybe some padding. 1567 */ 1568 *len = *P; 1569 if (*len > mlen - 1) { 1570 generr(h, "Mangled data seems to be garbage %zu %zu", 1571 *len, mlen-1); 1572 return NULL; 1573 } 1574 1575 if (*len > MPPE_KEY_LEN * 2) { 1576 generr(h, "Key to long (%zu) for me max. %d", 1577 *len, MPPE_KEY_LEN * 2); 1578 return NULL; 1579 } 1580 demangled = malloc(*len); 1581 if (!demangled) 1582 return NULL; 1583 1584 memcpy(demangled, P + 1, *len); 1585 return demangled; 1586 } 1587 1588 const char * 1589 rad_server_secret(struct rad_handle *h) 1590 { 1591 return (h->servers[h->srv].secret); 1592 } 1593