1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/types.h> 33 #include <sys/socket.h> 34 #include <sys/time.h> 35 #include <netinet/in.h> 36 #include <arpa/inet.h> 37 #ifdef WITH_SSL 38 #include <openssl/hmac.h> 39 #include <openssl/md5.h> 40 #define MD5Init MD5_Init 41 #define MD5Update MD5_Update 42 #define MD5Final MD5_Final 43 #else 44 #define MD5_DIGEST_LENGTH 16 45 #include <md5.h> 46 #endif 47 48 #define MAX_FIELDS 7 49 50 /* We need the MPPE_KEY_LEN define */ 51 #include <netgraph/ng_mppc.h> 52 53 #include <errno.h> 54 #include <netdb.h> 55 #include <stdarg.h> 56 #include <stddef.h> 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <string.h> 60 #include <unistd.h> 61 62 #include "radlib_private.h" 63 64 static void clear_password(struct rad_handle *); 65 static void generr(struct rad_handle *, const char *, ...) 66 __printflike(2, 3); 67 static void insert_scrambled_password(struct rad_handle *, int); 68 static void insert_request_authenticator(struct rad_handle *, int); 69 static void insert_message_authenticator(struct rad_handle *, int); 70 static int is_valid_response(struct rad_handle *, int, 71 const struct sockaddr_in *); 72 static int put_password_attr(struct rad_handle *, int, 73 const void *, size_t); 74 static int put_raw_attr(struct rad_handle *, int, 75 const void *, size_t); 76 static int split(char *, char *[], int, char *, size_t); 77 78 static void 79 clear_password(struct rad_handle *h) 80 { 81 if (h->pass_len != 0) { 82 explicit_bzero(h->pass, h->pass_len); 83 h->pass_len = 0; 84 } 85 h->pass_pos = 0; 86 } 87 88 static void 89 generr(struct rad_handle *h, const char *format, ...) 90 { 91 va_list ap; 92 93 va_start(ap, format); 94 vsnprintf(h->errmsg, ERRSIZE, format, ap); 95 va_end(ap); 96 } 97 98 static void 99 insert_scrambled_password(struct rad_handle *h, int srv) 100 { 101 MD5_CTX ctx; 102 unsigned char md5[MD5_DIGEST_LENGTH]; 103 const struct rad_server *srvp; 104 int padded_len; 105 int pos; 106 107 srvp = &h->servers[srv]; 108 padded_len = h->pass_len == 0 ? 16 : (h->pass_len+15) & ~0xf; 109 110 memcpy(md5, &h->out[POS_AUTH], LEN_AUTH); 111 for (pos = 0; pos < padded_len; pos += 16) { 112 int i; 113 114 /* Calculate the new scrambler */ 115 MD5Init(&ctx); 116 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 117 MD5Update(&ctx, md5, 16); 118 MD5Final(md5, &ctx); 119 120 /* 121 * Mix in the current chunk of the password, and copy 122 * the result into the right place in the request. Also 123 * modify the scrambler in place, since we will use this 124 * in calculating the scrambler for next time. 125 */ 126 for (i = 0; i < 16; i++) 127 h->out[h->pass_pos + pos + i] = 128 md5[i] ^= h->pass[pos + i]; 129 } 130 } 131 132 static void 133 insert_request_authenticator(struct rad_handle *h, int resp) 134 { 135 MD5_CTX ctx; 136 const struct rad_server *srvp; 137 138 srvp = &h->servers[h->srv]; 139 140 /* Create the request authenticator */ 141 MD5Init(&ctx); 142 MD5Update(&ctx, &h->out[POS_CODE], POS_AUTH - POS_CODE); 143 if (resp) 144 MD5Update(&ctx, &h->in[POS_AUTH], LEN_AUTH); 145 else 146 MD5Update(&ctx, &h->out[POS_AUTH], LEN_AUTH); 147 MD5Update(&ctx, &h->out[POS_ATTRS], h->out_len - POS_ATTRS); 148 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 149 MD5Final(&h->out[POS_AUTH], &ctx); 150 } 151 152 static void 153 insert_message_authenticator(struct rad_handle *h, int resp) 154 { 155 #ifdef WITH_SSL 156 u_char md[EVP_MAX_MD_SIZE]; 157 u_int md_len; 158 const struct rad_server *srvp; 159 HMAC_CTX *ctx; 160 srvp = &h->servers[h->srv]; 161 162 if (h->authentic_pos != 0) { 163 ctx = HMAC_CTX_new(); 164 HMAC_Init_ex(ctx, srvp->secret, strlen(srvp->secret), EVP_md5(), NULL); 165 HMAC_Update(ctx, &h->out[POS_CODE], POS_AUTH - POS_CODE); 166 if (resp) 167 HMAC_Update(ctx, &h->in[POS_AUTH], LEN_AUTH); 168 else 169 HMAC_Update(ctx, &h->out[POS_AUTH], LEN_AUTH); 170 HMAC_Update(ctx, &h->out[POS_ATTRS], 171 h->out_len - POS_ATTRS); 172 HMAC_Final(ctx, md, &md_len); 173 HMAC_CTX_free(ctx); 174 memcpy(&h->out[h->authentic_pos + 2], md, md_len); 175 } 176 #endif 177 } 178 179 /* 180 * Return true if the current response is valid for a request to the 181 * specified server. 182 */ 183 static int 184 is_valid_response(struct rad_handle *h, int srv, 185 const struct sockaddr_in *from) 186 { 187 MD5_CTX ctx; 188 unsigned char md5[MD5_DIGEST_LENGTH]; 189 const struct rad_server *srvp; 190 191 int len; 192 #ifdef WITH_SSL 193 int alen; 194 HMAC_CTX *hctx; 195 u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE]; 196 u_int md_len; 197 int pos; 198 #endif 199 200 srvp = &h->servers[srv]; 201 202 /* Check the source address */ 203 if (from->sin_family != srvp->addr.sin_family || 204 from->sin_addr.s_addr != srvp->addr.sin_addr.s_addr || 205 from->sin_port != srvp->addr.sin_port) 206 return 0; 207 208 /* Check the message length */ 209 if (h->in_len < POS_ATTRS) 210 return 0; 211 len = (h->in[POS_LENGTH] << 8) | h->in[POS_LENGTH + 1]; 212 if (len < POS_ATTRS || len > h->in_len) 213 return 0; 214 215 /* Check the response authenticator */ 216 MD5Init(&ctx); 217 MD5Update(&ctx, &h->in[POS_CODE], POS_AUTH - POS_CODE); 218 MD5Update(&ctx, &h->out[POS_AUTH], LEN_AUTH); 219 MD5Update(&ctx, &h->in[POS_ATTRS], len - POS_ATTRS); 220 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 221 MD5Final(md5, &ctx); 222 if (memcmp(&h->in[POS_AUTH], md5, sizeof md5) != 0) 223 return 0; 224 225 #ifdef WITH_SSL 226 /* 227 * For non accounting responses check the message authenticator, 228 * if any. 229 */ 230 if (h->in[POS_CODE] != RAD_ACCOUNTING_RESPONSE) { 231 232 memcpy(resp, h->in, MSGSIZE); 233 pos = POS_ATTRS; 234 235 /* Search and verify the Message-Authenticator */ 236 hctx = HMAC_CTX_new(); 237 while (pos < len - 2) { 238 if (h->in[pos] == RAD_MESSAGE_AUTHENTIC) { 239 if (h->in[pos + 1] != MD5_DIGEST_LENGTH + 2) { 240 HMAC_CTX_free(hctx); 241 return 0; 242 } 243 if (len - pos < MD5_DIGEST_LENGTH + 2) { 244 HMAC_CTX_free(hctx); 245 return 0; 246 } 247 248 memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH); 249 250 HMAC_Init_ex(hctx, srvp->secret, 251 strlen(srvp->secret), EVP_md5(), NULL); 252 HMAC_Update(hctx, &h->in[POS_CODE], 253 POS_AUTH - POS_CODE); 254 HMAC_Update(hctx, &h->out[POS_AUTH], 255 LEN_AUTH); 256 HMAC_Update(hctx, &resp[POS_ATTRS], 257 h->in_len - POS_ATTRS); 258 HMAC_Final(hctx, md, &md_len); 259 HMAC_CTX_reset(hctx); 260 if (memcmp(md, &h->in[pos + 2], 261 MD5_DIGEST_LENGTH) != 0) { 262 HMAC_CTX_free(hctx); 263 return 0; 264 } 265 break; 266 } 267 alen = h->in[pos + 1]; 268 if (alen < 2) { 269 HMAC_CTX_free(hctx); 270 return 0; 271 } 272 pos += alen; 273 } 274 HMAC_CTX_free(hctx); 275 } 276 #endif 277 return 1; 278 } 279 280 /* 281 * Return true if the current request is valid for the specified server. 282 */ 283 static int 284 is_valid_request(struct rad_handle *h) 285 { 286 MD5_CTX ctx; 287 unsigned char md5[MD5_DIGEST_LENGTH]; 288 const struct rad_server *srvp; 289 int len; 290 #ifdef WITH_SSL 291 int alen; 292 HMAC_CTX *hctx; 293 u_char resp[MSGSIZE], md[EVP_MAX_MD_SIZE]; 294 u_int md_len; 295 int pos; 296 #endif 297 298 srvp = &h->servers[h->srv]; 299 300 /* Check the message length */ 301 if (h->in_len < POS_ATTRS) 302 return (0); 303 len = (h->in[POS_LENGTH] << 8) | h->in[POS_LENGTH + 1]; 304 if (len < POS_ATTRS || len > h->in_len) 305 return (0); 306 307 if (h->in[POS_CODE] != RAD_ACCESS_REQUEST) { 308 uint32_t zeroes[4] = { 0, 0, 0, 0 }; 309 /* Check the request authenticator */ 310 MD5Init(&ctx); 311 MD5Update(&ctx, &h->in[POS_CODE], POS_AUTH - POS_CODE); 312 MD5Update(&ctx, zeroes, LEN_AUTH); 313 MD5Update(&ctx, &h->in[POS_ATTRS], len - POS_ATTRS); 314 MD5Update(&ctx, srvp->secret, strlen(srvp->secret)); 315 MD5Final(md5, &ctx); 316 if (memcmp(&h->in[POS_AUTH], md5, sizeof md5) != 0) 317 return (0); 318 } 319 320 #ifdef WITH_SSL 321 /* Search and verify the Message-Authenticator */ 322 pos = POS_ATTRS; 323 hctx = HMAC_CTX_new(); 324 while (pos < len - 2) { 325 alen = h->in[pos + 1]; 326 if (alen < 2) 327 return (0); 328 if (h->in[pos] == RAD_MESSAGE_AUTHENTIC) { 329 if (len - pos < MD5_DIGEST_LENGTH + 2) { 330 HMAC_CTX_free(hctx); 331 return (0); 332 } 333 if (alen < MD5_DIGEST_LENGTH + 2) { 334 HMAC_CTX_free(hctx); 335 return (0); 336 } 337 memcpy(resp, h->in, MSGSIZE); 338 /* zero fill the Request-Authenticator */ 339 if (h->in[POS_CODE] != RAD_ACCESS_REQUEST) 340 memset(&resp[POS_AUTH], 0, LEN_AUTH); 341 /* zero fill the Message-Authenticator */ 342 memset(&resp[pos + 2], 0, MD5_DIGEST_LENGTH); 343 344 HMAC_Init_ex(hctx, srvp->secret, 345 strlen(srvp->secret), EVP_md5(), NULL); 346 HMAC_Update(hctx, resp, h->in_len); 347 HMAC_Final(hctx, md, &md_len); 348 HMAC_CTX_reset(hctx); 349 if (memcmp(md, &h->in[pos + 2], 350 MD5_DIGEST_LENGTH) != 0) { 351 HMAC_CTX_free(hctx); 352 return (0); 353 } 354 break; 355 } 356 pos += alen; 357 } 358 HMAC_CTX_free(hctx); 359 #endif 360 return (1); 361 } 362 363 static int 364 put_password_attr(struct rad_handle *h, int type, const void *value, size_t len) 365 { 366 int padded_len; 367 int pad_len; 368 369 if (h->pass_pos != 0) { 370 generr(h, "Multiple User-Password attributes specified"); 371 return -1; 372 } 373 if (len > PASSSIZE) 374 len = PASSSIZE; 375 padded_len = len == 0 ? 16 : (len+15) & ~0xf; 376 pad_len = padded_len - len; 377 378 /* 379 * Put in a place-holder attribute containing all zeros, and 380 * remember where it is so we can fill it in later. 381 */ 382 clear_password(h); 383 put_raw_attr(h, type, h->pass, padded_len); 384 h->pass_pos = h->out_len - padded_len; 385 386 /* Save the cleartext password, padded as necessary */ 387 memcpy(h->pass, value, len); 388 h->pass_len = len; 389 memset(h->pass + len, 0, pad_len); 390 return 0; 391 } 392 393 static int 394 put_raw_attr(struct rad_handle *h, int type, const void *value, size_t len) 395 { 396 if (len > 253) { 397 generr(h, "Attribute too long"); 398 return -1; 399 } 400 if (h->out_len + 2 + len > MSGSIZE) { 401 generr(h, "Maximum message length exceeded"); 402 return -1; 403 } 404 h->out[h->out_len++] = type; 405 h->out[h->out_len++] = len + 2; 406 memcpy(&h->out[h->out_len], value, len); 407 h->out_len += len; 408 return 0; 409 } 410 411 int 412 rad_add_server(struct rad_handle *h, const char *host, int port, 413 const char *secret, int timeout, int tries) 414 { 415 struct in_addr bindto; 416 bindto.s_addr = INADDR_ANY; 417 418 return rad_add_server_ex(h, host, port, secret, timeout, tries, 419 DEAD_TIME, &bindto); 420 } 421 422 int 423 rad_add_server_ex(struct rad_handle *h, const char *host, int port, 424 const char *secret, int timeout, int tries, int dead_time, 425 struct in_addr *bindto) 426 { 427 struct rad_server *srvp; 428 429 if (h->num_servers >= MAXSERVERS) { 430 generr(h, "Too many RADIUS servers specified"); 431 return -1; 432 } 433 srvp = &h->servers[h->num_servers]; 434 435 memset(&srvp->addr, 0, sizeof srvp->addr); 436 srvp->addr.sin_len = sizeof srvp->addr; 437 srvp->addr.sin_family = AF_INET; 438 if (!inet_aton(host, &srvp->addr.sin_addr)) { 439 struct hostent *hent; 440 441 if ((hent = gethostbyname(host)) == NULL) { 442 generr(h, "%s: host not found", host); 443 return -1; 444 } 445 memcpy(&srvp->addr.sin_addr, hent->h_addr, 446 sizeof srvp->addr.sin_addr); 447 } 448 if (port != 0) 449 srvp->addr.sin_port = htons((u_short)port); 450 else { 451 struct servent *sent; 452 453 if (h->type == RADIUS_AUTH) 454 srvp->addr.sin_port = 455 (sent = getservbyname("radius", "udp")) != NULL ? 456 sent->s_port : htons(RADIUS_PORT); 457 else 458 srvp->addr.sin_port = 459 (sent = getservbyname("radacct", "udp")) != NULL ? 460 sent->s_port : htons(RADACCT_PORT); 461 } 462 if ((srvp->secret = strdup(secret)) == NULL) { 463 generr(h, "Out of memory"); 464 return -1; 465 } 466 srvp->timeout = timeout; 467 srvp->max_tries = tries; 468 srvp->num_tries = 0; 469 srvp->is_dead = 0; 470 srvp->dead_time = dead_time; 471 srvp->next_probe = 0; 472 srvp->bindto = bindto->s_addr; 473 h->num_servers++; 474 return 0; 475 } 476 477 void 478 rad_close(struct rad_handle *h) 479 { 480 int srv; 481 482 if (h->fd != -1) 483 close(h->fd); 484 for (srv = 0; srv < h->num_servers; srv++) { 485 memset(h->servers[srv].secret, 0, 486 strlen(h->servers[srv].secret)); 487 free(h->servers[srv].secret); 488 } 489 clear_password(h); 490 free(h); 491 } 492 493 void 494 rad_bind_to(struct rad_handle *h, in_addr_t addr) 495 { 496 497 h->bindto = addr; 498 } 499 500 int 501 rad_config(struct rad_handle *h, const char *path) 502 { 503 FILE *fp; 504 char buf[MAXCONFLINE]; 505 int linenum; 506 int retval; 507 508 if (path == NULL) 509 path = PATH_RADIUS_CONF; 510 if ((fp = fopen(path, "r")) == NULL) { 511 generr(h, "Cannot open \"%s\": %s", path, strerror(errno)); 512 return -1; 513 } 514 retval = 0; 515 linenum = 0; 516 while (fgets(buf, sizeof buf, fp) != NULL) { 517 int len; 518 char *fields[MAX_FIELDS]; 519 int nfields; 520 char msg[ERRSIZE]; 521 char *type; 522 char *host, *res; 523 char *port_str; 524 char *secret; 525 char *timeout_str; 526 char *maxtries_str; 527 char *dead_time_str; 528 char *bindto_str; 529 char *end; 530 char *wanttype; 531 unsigned long timeout; 532 unsigned long maxtries; 533 unsigned long dead_time; 534 int port; 535 struct in_addr bindto; 536 int i; 537 538 linenum++; 539 len = strlen(buf); 540 /* We know len > 0, else fgets would have returned NULL. */ 541 if (buf[len - 1] != '\n') { 542 if (len == sizeof buf - 1) 543 generr(h, "%s:%d: line too long", path, 544 linenum); 545 else 546 generr(h, "%s:%d: missing newline", path, 547 linenum); 548 retval = -1; 549 break; 550 } 551 buf[len - 1] = '\0'; 552 553 /* Extract the fields from the line. */ 554 nfields = split(buf, fields, MAX_FIELDS, msg, sizeof msg); 555 if (nfields == -1) { 556 generr(h, "%s:%d: %s", path, linenum, msg); 557 retval = -1; 558 break; 559 } 560 if (nfields == 0) 561 continue; 562 /* 563 * The first field should contain "auth" or "acct" for 564 * authentication or accounting, respectively. But older 565 * versions of the file didn't have that field. Default 566 * it to "auth" for backward compatibility. 567 */ 568 if (strcmp(fields[0], "auth") != 0 && 569 strcmp(fields[0], "acct") != 0) { 570 if (nfields >= MAX_FIELDS) { 571 generr(h, "%s:%d: invalid service type", path, 572 linenum); 573 retval = -1; 574 break; 575 } 576 nfields++; 577 for (i = nfields; --i > 0; ) 578 fields[i] = fields[i - 1]; 579 fields[0] = "auth"; 580 } 581 if (nfields < 3) { 582 generr(h, "%s:%d: missing shared secret", path, 583 linenum); 584 retval = -1; 585 break; 586 } 587 type = fields[0]; 588 host = fields[1]; 589 secret = fields[2]; 590 timeout_str = fields[3]; 591 maxtries_str = fields[4]; 592 dead_time_str = fields[5]; 593 bindto_str = fields[6]; 594 595 /* Ignore the line if it is for the wrong service type. */ 596 wanttype = h->type == RADIUS_AUTH ? "auth" : "acct"; 597 if (strcmp(type, wanttype) != 0) 598 continue; 599 600 /* Parse and validate the fields. */ 601 res = host; 602 host = strsep(&res, ":"); 603 port_str = strsep(&res, ":"); 604 if (port_str != NULL) { 605 port = strtoul(port_str, &end, 10); 606 if (*end != '\0') { 607 generr(h, "%s:%d: invalid port", path, 608 linenum); 609 retval = -1; 610 break; 611 } 612 } else 613 port = 0; 614 if (timeout_str != NULL) { 615 timeout = strtoul(timeout_str, &end, 10); 616 if (*end != '\0') { 617 generr(h, "%s:%d: invalid timeout", path, 618 linenum); 619 retval = -1; 620 break; 621 } 622 } else 623 timeout = TIMEOUT; 624 if (maxtries_str != NULL) { 625 maxtries = strtoul(maxtries_str, &end, 10); 626 if (*end != '\0') { 627 generr(h, "%s:%d: invalid maxtries", path, 628 linenum); 629 retval = -1; 630 break; 631 } 632 } else 633 maxtries = MAXTRIES; 634 635 if (dead_time_str != NULL) { 636 dead_time = strtoul(dead_time_str, &end, 10); 637 if (*end != '\0') { 638 generr(h, "%s:%d: invalid dead_time", path, 639 linenum); 640 retval = -1; 641 break; 642 } 643 } else 644 dead_time = DEAD_TIME; 645 646 if (bindto_str != NULL) { 647 bindto.s_addr = inet_addr(bindto_str); 648 if (bindto.s_addr == INADDR_NONE) { 649 generr(h, "%s:%d: invalid bindto", path, 650 linenum); 651 retval = -1; 652 break; 653 } 654 } else 655 bindto.s_addr = INADDR_ANY; 656 657 if (rad_add_server_ex(h, host, port, secret, timeout, maxtries, 658 dead_time, &bindto) == -1) { 659 strcpy(msg, h->errmsg); 660 generr(h, "%s:%d: %s", path, linenum, msg); 661 retval = -1; 662 break; 663 } 664 } 665 /* Clear out the buffer to wipe a possible copy of a shared secret */ 666 memset(buf, 0, sizeof buf); 667 fclose(fp); 668 return retval; 669 } 670 671 /* 672 * rad_init_send_request() must have previously been called. 673 * Returns: 674 * 0 The application should select on *fd with a timeout of tv before 675 * calling rad_continue_send_request again. 676 * < 0 Failure 677 * > 0 Success 678 */ 679 int 680 rad_continue_send_request(struct rad_handle *h, int selected, int *fd, 681 struct timeval *tv) 682 { 683 int n, cur_srv; 684 time_t now; 685 struct sockaddr_in sin; 686 687 if (h->type == RADIUS_SERVER) { 688 generr(h, "denied function call"); 689 return (-1); 690 } 691 if (selected) { 692 struct sockaddr_in from; 693 socklen_t fromlen; 694 695 fromlen = sizeof from; 696 h->in_len = recvfrom(h->fd, h->in, 697 MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen); 698 if (h->in_len == -1) { 699 generr(h, "recvfrom: %s", strerror(errno)); 700 return -1; 701 } 702 if (is_valid_response(h, h->srv, &from)) { 703 h->in_len = h->in[POS_LENGTH] << 8 | 704 h->in[POS_LENGTH+1]; 705 h->in_pos = POS_ATTRS; 706 return h->in[POS_CODE]; 707 } 708 } 709 710 /* 711 * Scan round-robin to the next server that has some 712 * tries left. There is guaranteed to be one, or we 713 * would have exited this loop by now. 714 */ 715 cur_srv = h->srv; 716 now = time(NULL); 717 if (h->servers[h->srv].num_tries >= h->servers[h->srv].max_tries) { 718 /* Set next probe time for this server */ 719 if (h->servers[h->srv].dead_time) { 720 h->servers[h->srv].is_dead = 1; 721 h->servers[h->srv].next_probe = now + 722 h->servers[h->srv].dead_time; 723 } 724 do { 725 h->srv++; 726 if (h->srv >= h->num_servers) 727 h->srv = 0; 728 if (h->servers[h->srv].is_dead == 0) 729 break; 730 if (h->servers[h->srv].dead_time && 731 h->servers[h->srv].next_probe <= now) { 732 h->servers[h->srv].is_dead = 0; 733 h->servers[h->srv].num_tries = 0; 734 break; 735 } 736 } while (h->srv != cur_srv); 737 738 if (h->srv == cur_srv) { 739 generr(h, "No valid RADIUS responses received"); 740 return (-1); 741 } 742 } 743 744 /* Rebind */ 745 if (h->bindto != h->servers[h->srv].bindto) { 746 h->bindto = h->servers[h->srv].bindto; 747 close(h->fd); 748 if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) { 749 generr(h, "Cannot create socket: %s", strerror(errno)); 750 return -1; 751 } 752 memset(&sin, 0, sizeof sin); 753 sin.sin_len = sizeof sin; 754 sin.sin_family = AF_INET; 755 sin.sin_addr.s_addr = h->bindto; 756 sin.sin_port = 0; 757 if (bind(h->fd, (const struct sockaddr *)&sin, 758 sizeof sin) == -1) { 759 generr(h, "bind: %s", strerror(errno)); 760 close(h->fd); 761 h->fd = -1; 762 return (-1); 763 } 764 } 765 766 if (h->out[POS_CODE] == RAD_ACCESS_REQUEST) { 767 /* Insert the scrambled password into the request */ 768 if (h->pass_pos != 0) 769 insert_scrambled_password(h, h->srv); 770 } 771 insert_message_authenticator(h, 0); 772 773 if (h->out[POS_CODE] != RAD_ACCESS_REQUEST) { 774 /* Insert the request authenticator into the request */ 775 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 776 insert_request_authenticator(h, 0); 777 } 778 779 /* Send the request */ 780 n = sendto(h->fd, h->out, h->out_len, 0, 781 (const struct sockaddr *)&h->servers[h->srv].addr, 782 sizeof h->servers[h->srv].addr); 783 if (n != h->out_len) 784 tv->tv_sec = 1; /* Do not wait full timeout if send failed. */ 785 else 786 tv->tv_sec = h->servers[h->srv].timeout; 787 h->servers[h->srv].num_tries++; 788 tv->tv_usec = 0; 789 *fd = h->fd; 790 791 return 0; 792 } 793 794 int 795 rad_receive_request(struct rad_handle *h) 796 { 797 struct sockaddr_in from; 798 socklen_t fromlen; 799 int n; 800 801 if (h->type != RADIUS_SERVER) { 802 generr(h, "denied function call"); 803 return (-1); 804 } 805 h->srv = -1; 806 fromlen = sizeof(from); 807 h->in_len = recvfrom(h->fd, h->in, 808 MSGSIZE, MSG_WAITALL, (struct sockaddr *)&from, &fromlen); 809 if (h->in_len == -1) { 810 generr(h, "recvfrom: %s", strerror(errno)); 811 return (-1); 812 } 813 for (n = 0; n < h->num_servers; n++) { 814 if (h->servers[n].addr.sin_addr.s_addr == from.sin_addr.s_addr) { 815 h->servers[n].addr.sin_port = from.sin_port; 816 h->srv = n; 817 break; 818 } 819 } 820 if (h->srv == -1) 821 return (-2); 822 if (is_valid_request(h)) { 823 h->in_len = h->in[POS_LENGTH] << 8 | 824 h->in[POS_LENGTH+1]; 825 h->in_pos = POS_ATTRS; 826 return (h->in[POS_CODE]); 827 } 828 return (-3); 829 } 830 831 int 832 rad_send_response(struct rad_handle *h) 833 { 834 int n; 835 836 if (h->type != RADIUS_SERVER) { 837 generr(h, "denied function call"); 838 return (-1); 839 } 840 /* Fill in the length field in the message */ 841 h->out[POS_LENGTH] = h->out_len >> 8; 842 h->out[POS_LENGTH+1] = h->out_len; 843 844 insert_message_authenticator(h, 845 (h->in[POS_CODE] == RAD_ACCESS_REQUEST) ? 1 : 0); 846 insert_request_authenticator(h, 1); 847 848 /* Send the request */ 849 n = sendto(h->fd, h->out, h->out_len, 0, 850 (const struct sockaddr *)&h->servers[h->srv].addr, 851 sizeof h->servers[h->srv].addr); 852 if (n != h->out_len) { 853 if (n == -1) 854 generr(h, "sendto: %s", strerror(errno)); 855 else 856 generr(h, "sendto: short write"); 857 return -1; 858 } 859 860 return 0; 861 } 862 863 int 864 rad_create_request(struct rad_handle *h, int code) 865 { 866 int i; 867 868 if (h->type == RADIUS_SERVER) { 869 generr(h, "denied function call"); 870 return (-1); 871 } 872 if (h->num_servers == 0) { 873 generr(h, "No RADIUS servers specified"); 874 return (-1); 875 } 876 h->out[POS_CODE] = code; 877 h->out[POS_IDENT] = ++h->ident; 878 if (code == RAD_ACCESS_REQUEST) { 879 /* Create a random authenticator */ 880 for (i = 0; i < LEN_AUTH; i += 2) { 881 uint32_t r; 882 r = arc4random(); 883 h->out[POS_AUTH+i] = (u_char)r; 884 h->out[POS_AUTH+i+1] = (u_char)(r >> 8); 885 } 886 } else 887 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 888 h->out_len = POS_ATTRS; 889 clear_password(h); 890 h->authentic_pos = 0; 891 h->out_created = 1; 892 return 0; 893 } 894 895 int 896 rad_create_response(struct rad_handle *h, int code) 897 { 898 899 if (h->type != RADIUS_SERVER) { 900 generr(h, "denied function call"); 901 return (-1); 902 } 903 h->out[POS_CODE] = code; 904 h->out[POS_IDENT] = h->in[POS_IDENT]; 905 memset(&h->out[POS_AUTH], 0, LEN_AUTH); 906 h->out_len = POS_ATTRS; 907 clear_password(h); 908 h->authentic_pos = 0; 909 h->out_created = 1; 910 return 0; 911 } 912 913 struct in_addr 914 rad_cvt_addr(const void *data) 915 { 916 struct in_addr value; 917 918 memcpy(&value.s_addr, data, sizeof value.s_addr); 919 return value; 920 } 921 922 struct in6_addr 923 rad_cvt_addr6(const void *data) 924 { 925 struct in6_addr value; 926 927 memcpy(&value.s6_addr, data, sizeof value.s6_addr); 928 return value; 929 } 930 931 u_int32_t 932 rad_cvt_int(const void *data) 933 { 934 u_int32_t value; 935 936 memcpy(&value, data, sizeof value); 937 return ntohl(value); 938 } 939 940 char * 941 rad_cvt_string(const void *data, size_t len) 942 { 943 char *s; 944 945 s = malloc(len + 1); 946 if (s != NULL) { 947 memcpy(s, data, len); 948 s[len] = '\0'; 949 } 950 return s; 951 } 952 953 /* 954 * Returns the attribute type. If none are left, returns 0. On failure, 955 * returns -1. 956 */ 957 int 958 rad_get_attr(struct rad_handle *h, const void **value, size_t *lenp) 959 { 960 int len, type; 961 962 if (h->in_pos >= h->in_len) 963 return 0; 964 if (h->in_pos + 2 > h->in_len) { 965 generr(h, "Malformed attribute in response"); 966 return -1; 967 } 968 type = h->in[h->in_pos++]; 969 len = h->in[h->in_pos++]; 970 if (len < 2) { 971 generr(h, "Malformed attribute in response"); 972 return -1; 973 } 974 len -= 2; 975 if (h->in_pos + len > h->in_len) { 976 generr(h, "Malformed attribute in response"); 977 return -1; 978 } 979 *lenp = len; 980 *value = &h->in[h->in_pos]; 981 h->in_pos += len; 982 return type; 983 } 984 985 /* 986 * Returns -1 on error, 0 to indicate no event and >0 for success 987 */ 988 int 989 rad_init_send_request(struct rad_handle *h, int *fd, struct timeval *tv) 990 { 991 int srv; 992 time_t now; 993 struct sockaddr_in sin; 994 995 if (h->type == RADIUS_SERVER) { 996 generr(h, "denied function call"); 997 return (-1); 998 } 999 /* Make sure we have a socket to use */ 1000 if (h->fd == -1) { 1001 if ((h->fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) { 1002 generr(h, "Cannot create socket: %s", strerror(errno)); 1003 return -1; 1004 } 1005 memset(&sin, 0, sizeof sin); 1006 sin.sin_len = sizeof sin; 1007 sin.sin_family = AF_INET; 1008 sin.sin_addr.s_addr = h->bindto; 1009 sin.sin_port = htons(0); 1010 if (bind(h->fd, (const struct sockaddr *)&sin, 1011 sizeof sin) == -1) { 1012 generr(h, "bind: %s", strerror(errno)); 1013 close(h->fd); 1014 h->fd = -1; 1015 return -1; 1016 } 1017 } 1018 1019 if (h->out[POS_CODE] != RAD_ACCESS_REQUEST) { 1020 /* Make sure no password given */ 1021 if (h->pass_pos || h->chap_pass) { 1022 generr(h, "User or Chap Password" 1023 " in accounting request"); 1024 return -1; 1025 } 1026 } else { 1027 if (h->eap_msg == 0) { 1028 /* Make sure the user gave us a password */ 1029 if (h->pass_pos == 0 && !h->chap_pass) { 1030 generr(h, "No User or Chap Password" 1031 " attributes given"); 1032 return -1; 1033 } 1034 if (h->pass_pos != 0 && h->chap_pass) { 1035 generr(h, "Both User and Chap Password" 1036 " attributes given"); 1037 return -1; 1038 } 1039 } 1040 } 1041 1042 /* Fill in the length field in the message */ 1043 h->out[POS_LENGTH] = h->out_len >> 8; 1044 h->out[POS_LENGTH+1] = h->out_len; 1045 1046 h->srv = 0; 1047 now = time(NULL); 1048 for (srv = 0; srv < h->num_servers; srv++) 1049 h->servers[srv].num_tries = 0; 1050 /* Find a first good server. */ 1051 for (srv = 0; srv < h->num_servers; srv++) { 1052 if (h->servers[srv].is_dead == 0) 1053 break; 1054 if (h->servers[srv].dead_time && 1055 h->servers[srv].next_probe <= now) { 1056 h->servers[srv].is_dead = 0; 1057 break; 1058 } 1059 h->srv++; 1060 } 1061 1062 /* If all servers was dead on the last probe, try from beginning */ 1063 if (h->srv == h->num_servers) { 1064 for (srv = 0; srv < h->num_servers; srv++) { 1065 h->servers[srv].is_dead = 0; 1066 h->servers[srv].next_probe = 0; 1067 } 1068 h->srv = 0; 1069 } 1070 1071 return rad_continue_send_request(h, 0, fd, tv); 1072 } 1073 1074 /* 1075 * Create and initialize a rad_handle structure, and return it to the 1076 * caller. Can fail only if the necessary memory cannot be allocated. 1077 * In that case, it returns NULL. 1078 */ 1079 struct rad_handle * 1080 rad_auth_open(void) 1081 { 1082 struct rad_handle *h; 1083 1084 h = (struct rad_handle *)malloc(sizeof(struct rad_handle)); 1085 if (h != NULL) { 1086 h->fd = -1; 1087 h->num_servers = 0; 1088 h->ident = arc4random(); 1089 h->errmsg[0] = '\0'; 1090 memset(h->pass, 0, sizeof h->pass); 1091 h->pass_len = 0; 1092 h->pass_pos = 0; 1093 h->chap_pass = 0; 1094 h->authentic_pos = 0; 1095 h->type = RADIUS_AUTH; 1096 h->out_created = 0; 1097 h->eap_msg = 0; 1098 h->bindto = INADDR_ANY; 1099 } 1100 return h; 1101 } 1102 1103 struct rad_handle * 1104 rad_acct_open(void) 1105 { 1106 struct rad_handle *h; 1107 1108 h = rad_open(); 1109 if (h != NULL) 1110 h->type = RADIUS_ACCT; 1111 return h; 1112 } 1113 1114 struct rad_handle * 1115 rad_server_open(int fd) 1116 { 1117 struct rad_handle *h; 1118 1119 h = rad_open(); 1120 if (h != NULL) { 1121 h->type = RADIUS_SERVER; 1122 h->fd = fd; 1123 } 1124 return h; 1125 } 1126 1127 struct rad_handle * 1128 rad_open(void) 1129 { 1130 return rad_auth_open(); 1131 } 1132 1133 int 1134 rad_put_addr(struct rad_handle *h, int type, struct in_addr addr) 1135 { 1136 return rad_put_attr(h, type, &addr.s_addr, sizeof addr.s_addr); 1137 } 1138 1139 int 1140 rad_put_addr6(struct rad_handle *h, int type, struct in6_addr addr) 1141 { 1142 1143 return rad_put_attr(h, type, &addr.s6_addr, sizeof addr.s6_addr); 1144 } 1145 1146 int 1147 rad_put_attr(struct rad_handle *h, int type, const void *value, size_t len) 1148 { 1149 int result; 1150 1151 if (!h->out_created) { 1152 generr(h, "Please call rad_create_request()" 1153 " before putting attributes"); 1154 return -1; 1155 } 1156 1157 if (h->out[POS_CODE] == RAD_ACCOUNTING_REQUEST) { 1158 if (type == RAD_EAP_MESSAGE) { 1159 generr(h, "EAP-Message attribute is not valid" 1160 " in accounting requests"); 1161 return -1; 1162 } 1163 } 1164 1165 /* 1166 * When proxying EAP Messages, the Message Authenticator 1167 * MUST be present; see RFC 3579. 1168 */ 1169 if (type == RAD_EAP_MESSAGE) { 1170 if (rad_put_message_authentic(h) == -1) 1171 return -1; 1172 } 1173 1174 if (type == RAD_USER_PASSWORD) { 1175 result = put_password_attr(h, type, value, len); 1176 } else if (type == RAD_MESSAGE_AUTHENTIC) { 1177 result = rad_put_message_authentic(h); 1178 } else { 1179 result = put_raw_attr(h, type, value, len); 1180 if (result == 0) { 1181 if (type == RAD_CHAP_PASSWORD) 1182 h->chap_pass = 1; 1183 else if (type == RAD_EAP_MESSAGE) 1184 h->eap_msg = 1; 1185 } 1186 } 1187 1188 return result; 1189 } 1190 1191 int 1192 rad_put_int(struct rad_handle *h, int type, u_int32_t value) 1193 { 1194 u_int32_t nvalue; 1195 1196 nvalue = htonl(value); 1197 return rad_put_attr(h, type, &nvalue, sizeof nvalue); 1198 } 1199 1200 int 1201 rad_put_string(struct rad_handle *h, int type, const char *str) 1202 { 1203 return rad_put_attr(h, type, str, strlen(str)); 1204 } 1205 1206 int 1207 rad_put_message_authentic(struct rad_handle *h) 1208 { 1209 #ifdef WITH_SSL 1210 u_char md_zero[MD5_DIGEST_LENGTH]; 1211 1212 if (h->out[POS_CODE] == RAD_ACCOUNTING_REQUEST) { 1213 generr(h, "Message-Authenticator is not valid" 1214 " in accounting requests"); 1215 return -1; 1216 } 1217 1218 if (h->authentic_pos == 0) { 1219 h->authentic_pos = h->out_len; 1220 memset(md_zero, 0, sizeof(md_zero)); 1221 return (put_raw_attr(h, RAD_MESSAGE_AUTHENTIC, md_zero, 1222 sizeof(md_zero))); 1223 } 1224 return 0; 1225 #else 1226 generr(h, "Message Authenticator not supported," 1227 " please recompile libradius with SSL support"); 1228 return -1; 1229 #endif 1230 } 1231 1232 /* 1233 * Returns the response type code on success, or -1 on failure. 1234 */ 1235 int 1236 rad_send_request(struct rad_handle *h) 1237 { 1238 struct timeval timelimit; 1239 struct timeval tv; 1240 int fd; 1241 int n; 1242 1243 n = rad_init_send_request(h, &fd, &tv); 1244 1245 if (n != 0) 1246 return n; 1247 1248 gettimeofday(&timelimit, NULL); 1249 timeradd(&tv, &timelimit, &timelimit); 1250 1251 for ( ; ; ) { 1252 fd_set readfds; 1253 1254 FD_ZERO(&readfds); 1255 FD_SET(fd, &readfds); 1256 1257 n = select(fd + 1, &readfds, NULL, NULL, &tv); 1258 1259 if (n == -1) { 1260 generr(h, "select: %s", strerror(errno)); 1261 return -1; 1262 } 1263 1264 if (!FD_ISSET(fd, &readfds)) { 1265 /* Compute a new timeout */ 1266 gettimeofday(&tv, NULL); 1267 timersub(&timelimit, &tv, &tv); 1268 if (tv.tv_sec > 0 || (tv.tv_sec == 0 && tv.tv_usec > 0)) 1269 /* Continue the select */ 1270 continue; 1271 } 1272 1273 n = rad_continue_send_request(h, n, &fd, &tv); 1274 1275 if (n != 0) 1276 return n; 1277 1278 gettimeofday(&timelimit, NULL); 1279 timeradd(&tv, &timelimit, &timelimit); 1280 } 1281 } 1282 1283 const char * 1284 rad_strerror(struct rad_handle *h) 1285 { 1286 return h->errmsg; 1287 } 1288 1289 /* 1290 * Destructively split a string into fields separated by white space. 1291 * `#' at the beginning of a field begins a comment that extends to the 1292 * end of the string. Fields may be quoted with `"'. Inside quoted 1293 * strings, the backslash escapes `\"' and `\\' are honored. 1294 * 1295 * Pointers to up to the first maxfields fields are stored in the fields 1296 * array. Missing fields get NULL pointers. 1297 * 1298 * The return value is the actual number of fields parsed, and is always 1299 * <= maxfields. 1300 * 1301 * On a syntax error, places a message in the msg string, and returns -1. 1302 */ 1303 static int 1304 split(char *str, char *fields[], int maxfields, char *msg, size_t msglen) 1305 { 1306 char *p; 1307 int i; 1308 static const char ws[] = " \t"; 1309 1310 for (i = 0; i < maxfields; i++) 1311 fields[i] = NULL; 1312 p = str; 1313 i = 0; 1314 while (*p != '\0') { 1315 p += strspn(p, ws); 1316 if (*p == '#' || *p == '\0') 1317 break; 1318 if (i >= maxfields) { 1319 snprintf(msg, msglen, "line has too many fields"); 1320 return -1; 1321 } 1322 if (*p == '"') { 1323 char *dst; 1324 1325 dst = ++p; 1326 fields[i] = dst; 1327 while (*p != '"') { 1328 if (*p == '\\') { 1329 p++; 1330 if (*p != '"' && *p != '\\' && 1331 *p != '\0') { 1332 snprintf(msg, msglen, 1333 "invalid `\\' escape"); 1334 return -1; 1335 } 1336 } 1337 if (*p == '\0') { 1338 snprintf(msg, msglen, 1339 "unterminated quoted string"); 1340 return -1; 1341 } 1342 *dst++ = *p++; 1343 } 1344 *dst = '\0'; 1345 p++; 1346 if (*fields[i] == '\0') { 1347 snprintf(msg, msglen, 1348 "empty quoted string not permitted"); 1349 return -1; 1350 } 1351 if (*p != '\0' && strspn(p, ws) == 0) { 1352 snprintf(msg, msglen, "quoted string not" 1353 " followed by white space"); 1354 return -1; 1355 } 1356 } else { 1357 fields[i] = p; 1358 p += strcspn(p, ws); 1359 if (*p != '\0') 1360 *p++ = '\0'; 1361 } 1362 i++; 1363 } 1364 return i; 1365 } 1366 1367 int 1368 rad_get_vendor_attr(u_int32_t *vendor, const void **data, size_t *len) 1369 { 1370 struct vendor_attribute *attr; 1371 1372 attr = (struct vendor_attribute *)*data; 1373 *vendor = ntohl(attr->vendor_value); 1374 *data = attr->attrib_data; 1375 *len = attr->attrib_len - 2; 1376 1377 return (attr->attrib_type); 1378 } 1379 1380 int 1381 rad_put_vendor_addr(struct rad_handle *h, int vendor, int type, 1382 struct in_addr addr) 1383 { 1384 return (rad_put_vendor_attr(h, vendor, type, &addr.s_addr, 1385 sizeof addr.s_addr)); 1386 } 1387 1388 int 1389 rad_put_vendor_addr6(struct rad_handle *h, int vendor, int type, 1390 struct in6_addr addr) 1391 { 1392 1393 return (rad_put_vendor_attr(h, vendor, type, &addr.s6_addr, 1394 sizeof addr.s6_addr)); 1395 } 1396 1397 int 1398 rad_put_vendor_attr(struct rad_handle *h, int vendor, int type, 1399 const void *value, size_t len) 1400 { 1401 struct vendor_attribute *attr; 1402 int res; 1403 1404 if (!h->out_created) { 1405 generr(h, "Please call rad_create_request()" 1406 " before putting attributes"); 1407 return -1; 1408 } 1409 1410 if ((attr = malloc(len + 6)) == NULL) { 1411 generr(h, "malloc failure (%zu bytes)", len + 6); 1412 return -1; 1413 } 1414 1415 attr->vendor_value = htonl(vendor); 1416 attr->attrib_type = type; 1417 attr->attrib_len = len + 2; 1418 memcpy(attr->attrib_data, value, len); 1419 1420 res = put_raw_attr(h, RAD_VENDOR_SPECIFIC, attr, len + 6); 1421 free(attr); 1422 if (res == 0 && vendor == RAD_VENDOR_MICROSOFT 1423 && (type == RAD_MICROSOFT_MS_CHAP_RESPONSE 1424 || type == RAD_MICROSOFT_MS_CHAP2_RESPONSE)) { 1425 h->chap_pass = 1; 1426 } 1427 return (res); 1428 } 1429 1430 int 1431 rad_put_vendor_int(struct rad_handle *h, int vendor, int type, u_int32_t i) 1432 { 1433 u_int32_t value; 1434 1435 value = htonl(i); 1436 return (rad_put_vendor_attr(h, vendor, type, &value, sizeof value)); 1437 } 1438 1439 int 1440 rad_put_vendor_string(struct rad_handle *h, int vendor, int type, 1441 const char *str) 1442 { 1443 return (rad_put_vendor_attr(h, vendor, type, str, strlen(str))); 1444 } 1445 1446 ssize_t 1447 rad_request_authenticator(struct rad_handle *h, char *buf, size_t len) 1448 { 1449 if (len < LEN_AUTH) 1450 return (-1); 1451 memcpy(buf, h->out + POS_AUTH, LEN_AUTH); 1452 if (len > LEN_AUTH) 1453 buf[LEN_AUTH] = '\0'; 1454 return (LEN_AUTH); 1455 } 1456 1457 u_char * 1458 rad_demangle(struct rad_handle *h, const void *mangled, size_t mlen) 1459 { 1460 char R[LEN_AUTH]; 1461 const char *S; 1462 int i, Ppos; 1463 MD5_CTX Context; 1464 u_char b[MD5_DIGEST_LENGTH], *C, *demangled; 1465 1466 if ((mlen % 16 != 0) || mlen > 128) { 1467 generr(h, "Cannot interpret mangled data of length %lu", 1468 (u_long)mlen); 1469 return NULL; 1470 } 1471 1472 C = (u_char *)mangled; 1473 1474 /* We need the shared secret as Salt */ 1475 S = rad_server_secret(h); 1476 1477 /* We need the request authenticator */ 1478 if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) { 1479 generr(h, "Cannot obtain the RADIUS request authenticator"); 1480 return NULL; 1481 } 1482 1483 demangled = malloc(mlen); 1484 if (!demangled) 1485 return NULL; 1486 1487 MD5Init(&Context); 1488 MD5Update(&Context, S, strlen(S)); 1489 MD5Update(&Context, R, LEN_AUTH); 1490 MD5Final(b, &Context); 1491 Ppos = 0; 1492 while (mlen) { 1493 1494 mlen -= 16; 1495 for (i = 0; i < 16; i++) 1496 demangled[Ppos++] = C[i] ^ b[i]; 1497 1498 if (mlen) { 1499 MD5Init(&Context); 1500 MD5Update(&Context, S, strlen(S)); 1501 MD5Update(&Context, C, 16); 1502 MD5Final(b, &Context); 1503 } 1504 1505 C += 16; 1506 } 1507 1508 return demangled; 1509 } 1510 1511 u_char * 1512 rad_demangle_mppe_key(struct rad_handle *h, const void *mangled, 1513 size_t mlen, size_t *len) 1514 { 1515 char R[LEN_AUTH]; /* variable names as per rfc2548 */ 1516 const char *S; 1517 u_char b[MD5_DIGEST_LENGTH], *demangled; 1518 const u_char *A, *C; 1519 MD5_CTX Context; 1520 int Slen, i, Clen, Ppos; 1521 u_char *P; 1522 1523 if (mlen % 16 != SALT_LEN) { 1524 generr(h, "Cannot interpret mangled data of length %lu", 1525 (u_long)mlen); 1526 return NULL; 1527 } 1528 1529 /* We need the RADIUS Request-Authenticator */ 1530 if (rad_request_authenticator(h, R, sizeof R) != LEN_AUTH) { 1531 generr(h, "Cannot obtain the RADIUS request authenticator"); 1532 return NULL; 1533 } 1534 1535 A = (const u_char *)mangled; /* Salt comes first */ 1536 C = (const u_char *)mangled + SALT_LEN; /* Then the ciphertext */ 1537 Clen = mlen - SALT_LEN; 1538 S = rad_server_secret(h); /* We need the RADIUS secret */ 1539 Slen = strlen(S); 1540 P = alloca(Clen); /* We derive our plaintext */ 1541 1542 MD5Init(&Context); 1543 MD5Update(&Context, S, Slen); 1544 MD5Update(&Context, R, LEN_AUTH); 1545 MD5Update(&Context, A, SALT_LEN); 1546 MD5Final(b, &Context); 1547 Ppos = 0; 1548 1549 while (Clen) { 1550 Clen -= 16; 1551 1552 for (i = 0; i < 16; i++) 1553 P[Ppos++] = C[i] ^ b[i]; 1554 1555 if (Clen) { 1556 MD5Init(&Context); 1557 MD5Update(&Context, S, Slen); 1558 MD5Update(&Context, C, 16); 1559 MD5Final(b, &Context); 1560 } 1561 1562 C += 16; 1563 } 1564 1565 /* 1566 * The resulting plain text consists of a one-byte length, the text and 1567 * maybe some padding. 1568 */ 1569 *len = *P; 1570 if (*len > mlen - 1) { 1571 generr(h, "Mangled data seems to be garbage %zu %zu", 1572 *len, mlen-1); 1573 return NULL; 1574 } 1575 1576 if (*len > MPPE_KEY_LEN * 2) { 1577 generr(h, "Key to long (%zu) for me max. %d", 1578 *len, MPPE_KEY_LEN * 2); 1579 return NULL; 1580 } 1581 demangled = malloc(*len); 1582 if (!demangled) 1583 return NULL; 1584 1585 memcpy(demangled, P + 1, *len); 1586 return demangled; 1587 } 1588 1589 const char * 1590 rad_server_secret(struct rad_handle *h) 1591 { 1592 return (h->servers[h->srv].secret); 1593 } 1594