contrib/hostapd-0.4.9/radius.c

   1 /*
   2  * Host AP (software wireless LAN access point) user space daemon for
   3  * Host AP kernel driver / RADIUS client
   4  * Copyright (c) 2002-2005, Jouni Malinen <jkmaline@cc.hut.fi>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * Alternatively, this software may be distributed under the terms of BSD
  11  * license.
  12  *
  13  * See README and COPYING for more details.
  14  */
  15
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18 #include <unistd.h>
  19 #include <string.h>
  20 #include <signal.h>
  21 #include <sys/time.h>
  22 #ifndef CONFIG_NATIVE_WINDOWS
  23 #include <netinet/in.h>
  24 #include <sys/ioctl.h>
  25 #include <sys/socket.h>
  26 #include <arpa/inet.h>
  27 #endif /* CONFIG_NATIVE_WINDOWS */
  28
  29 #include "common.h"
  30 #include "radius.h"
  31 #include "md5.h"
  32 #include "crypto.h"
  33
  34
  35 struct radius_msg *radius_msg_new(u8 code, u8 identifier)
  36 {
  37         struct radius_msg *msg;
  38
  39         msg = (struct radius_msg *) malloc(sizeof(*msg));
  40         if (msg == NULL)
  41                 return NULL;
  42
  43         if (radius_msg_initialize(msg, RADIUS_DEFAULT_MSG_SIZE)) {
  44                 free(msg);
  45                 return NULL;
  46         }
  47
  48         radius_msg_set_hdr(msg, code, identifier);
  49
  50         return msg;
  51 }
  52
  53
  54 int radius_msg_initialize(struct radius_msg *msg, size_t init_len)
  55 {
  56         if (msg == NULL || init_len < sizeof(struct radius_hdr))
  57                 return -1;
  58
  59         memset(msg, 0, sizeof(*msg));
  60         msg->buf = (unsigned char *) malloc(init_len);
  61         if (msg->buf == NULL)
  62                 return -1;
  63         memset(msg->buf, 0, init_len);
  64
  65         msg->buf_size = init_len;
  66         msg->hdr = (struct radius_hdr *) msg->buf;
  67         msg->buf_used = sizeof(*msg->hdr);
  68
  69         msg->attrs = (struct radius_attr_hdr **)
  70                 malloc(RADIUS_DEFAULT_ATTR_COUNT * sizeof(*msg->attrs));
  71         if (msg->attrs == NULL) {
  72                 free(msg->buf);
  73                 msg->buf = NULL;
  74                 msg->hdr = NULL;
  75                 return -1;
  76         }
  77
  78         msg->attr_size = RADIUS_DEFAULT_ATTR_COUNT;
  79         msg->attr_used = 0;
  80
  81         return 0;
  82 }
  83
  84
  85 void radius_msg_set_hdr(struct radius_msg *msg, u8 code, u8 identifier)
  86 {
  87         msg->hdr->code = code;
  88         msg->hdr->identifier = identifier;
  89 }
  90
  91
  92 void radius_msg_free(struct radius_msg *msg)
  93 {
  94         if (msg->buf != NULL) {
  95                 free(msg->buf);
  96                 msg->buf = NULL;
  97                 msg->hdr = NULL;
  98         }
  99         msg->buf_size = msg->buf_used = 0;
 100
 101         if (msg->attrs != NULL) {
 102                 free(msg->attrs);
 103                 msg->attrs = NULL;
 104         }
 105         msg->attr_size = msg->attr_used = 0;
 106 }
 107
 108
 109 static const char *radius_code_string(u8 code)
 110 {
 111         switch (code) {
 112         case RADIUS_CODE_ACCESS_REQUEST: return "Access-Request";
 113         case RADIUS_CODE_ACCESS_ACCEPT: return "Access-Accept";
 114         case RADIUS_CODE_ACCESS_REJECT: return "Access-Reject";
 115         case RADIUS_CODE_ACCOUNTING_REQUEST: return "Accounting-Request";
 116         case RADIUS_CODE_ACCOUNTING_RESPONSE: return "Accounting-Response";
 117         case RADIUS_CODE_ACCESS_CHALLENGE: return "Access-Challenge";
 118         case RADIUS_CODE_STATUS_SERVER: return "Status-Server";
 119         case RADIUS_CODE_STATUS_CLIENT: return "Status-Client";
 120         case RADIUS_CODE_RESERVED: return "Reserved";
 121         default: return "?Unknown?";
 122         }
 123 }
 124
 125
 126 struct radius_attr_type {
 127         u8 type;
 128         char *name;
 129         enum {
 130                 RADIUS_ATTR_UNDIST, RADIUS_ATTR_TEXT, RADIUS_ATTR_IP,
 131                 RADIUS_ATTR_HEXDUMP, RADIUS_ATTR_INT32, RADIUS_ATTR_IPV6
 132         } data_type;
 133 };
 134
 135 static struct radius_attr_type radius_attrs[] =
 136 {
 137         { RADIUS_ATTR_USER_NAME, "User-Name", RADIUS_ATTR_TEXT },
 138         { RADIUS_ATTR_USER_PASSWORD, "User-Password", RADIUS_ATTR_UNDIST },
 139         { RADIUS_ATTR_NAS_IP_ADDRESS, "NAS-IP-Address", RADIUS_ATTR_IP },
 140         { RADIUS_ATTR_NAS_PORT, "NAS-Port", RADIUS_ATTR_INT32 },
 141         { RADIUS_ATTR_FRAMED_MTU, "Framed-MTU", RADIUS_ATTR_INT32 },
 142         { RADIUS_ATTR_STATE, "State", RADIUS_ATTR_UNDIST },
 143         { RADIUS_ATTR_CLASS, "Class", RADIUS_ATTR_UNDIST },
 144         { RADIUS_ATTR_VENDOR_SPECIFIC, "Vendor-Specific", RADIUS_ATTR_UNDIST },
 145         { RADIUS_ATTR_SESSION_TIMEOUT, "Session-Timeout", RADIUS_ATTR_INT32 },
 146         { RADIUS_ATTR_IDLE_TIMEOUT, "Idle-Timeout", RADIUS_ATTR_INT32 },
 147         { RADIUS_ATTR_TERMINATION_ACTION, "Termination-Action",
 148           RADIUS_ATTR_INT32 },
 149         { RADIUS_ATTR_CALLED_STATION_ID, "Called-Station-Id",
 150           RADIUS_ATTR_TEXT },
 151         { RADIUS_ATTR_CALLING_STATION_ID, "Calling-Station-Id",
 152           RADIUS_ATTR_TEXT },
 153         { RADIUS_ATTR_NAS_IDENTIFIER, "NAS-Identifier", RADIUS_ATTR_TEXT },
 154         { RADIUS_ATTR_ACCT_STATUS_TYPE, "Acct-Status-Type",
 155           RADIUS_ATTR_INT32 },
 156         { RADIUS_ATTR_ACCT_DELAY_TIME, "Acct-Delay-Time", RADIUS_ATTR_INT32 },
 157         { RADIUS_ATTR_ACCT_INPUT_OCTETS, "Acct-Input-Octets",
 158           RADIUS_ATTR_INT32 },
 159         { RADIUS_ATTR_ACCT_OUTPUT_OCTETS, "Acct-Output-Octets",
 160           RADIUS_ATTR_INT32 },
 161         { RADIUS_ATTR_ACCT_SESSION_ID, "Acct-Session-Id", RADIUS_ATTR_TEXT },
 162         { RADIUS_ATTR_ACCT_AUTHENTIC, "Acct-Authentic", RADIUS_ATTR_INT32 },
 163         { RADIUS_ATTR_ACCT_SESSION_TIME, "Acct-Session-Time",
 164           RADIUS_ATTR_INT32 },
 165         { RADIUS_ATTR_ACCT_INPUT_PACKETS, "Acct-Input-Packets",
 166           RADIUS_ATTR_INT32 },
 167         { RADIUS_ATTR_ACCT_OUTPUT_PACKETS, "Acct-Output-Packets",
 168           RADIUS_ATTR_INT32 },
 169         { RADIUS_ATTR_ACCT_TERMINATE_CAUSE, "Acct-Terminate-Cause",
 170           RADIUS_ATTR_INT32 },
 171         { RADIUS_ATTR_ACCT_MULTI_SESSION_ID, "Acct-Multi-Session-Id",
 172           RADIUS_ATTR_TEXT },
 173         { RADIUS_ATTR_ACCT_LINK_COUNT, "Acct-Link-Count", RADIUS_ATTR_INT32 },
 174         { RADIUS_ATTR_ACCT_INPUT_GIGAWORDS, "Acct-Input-Gigawords",
 175           RADIUS_ATTR_INT32 },
 176         { RADIUS_ATTR_ACCT_OUTPUT_GIGAWORDS, "Acct-Output-Gigawords",
 177           RADIUS_ATTR_INT32 },
 178         { RADIUS_ATTR_EVENT_TIMESTAMP, "Event-Timestamp",
 179           RADIUS_ATTR_INT32 },
 180         { RADIUS_ATTR_NAS_PORT_TYPE, "NAS-Port-Type", RADIUS_ATTR_INT32 },
 181         { RADIUS_ATTR_CONNECT_INFO, "Connect-Info", RADIUS_ATTR_TEXT },
 182         { RADIUS_ATTR_EAP_MESSAGE, "EAP-Message", RADIUS_ATTR_UNDIST },
 183         { RADIUS_ATTR_MESSAGE_AUTHENTICATOR, "Message-Authenticator",
 184           RADIUS_ATTR_UNDIST },
 185         { RADIUS_ATTR_ACCT_INTERIM_INTERVAL, "Acct-Interim-Interval",
 186           RADIUS_ATTR_INT32 },
 187         { RADIUS_ATTR_NAS_IPV6_ADDRESS, "NAS-IPv6-Address", RADIUS_ATTR_IPV6 },
 188 };
 189 #define RADIUS_ATTRS (sizeof(radius_attrs) / sizeof(radius_attrs[0]))
 190
 191
 192 static struct radius_attr_type *radius_get_attr_type(u8 type)
 193 {
 194         int i;
 195
 196         for (i = 0; i < RADIUS_ATTRS; i++) {
 197                 if (type == radius_attrs[i].type)
 198                         return &radius_attrs[i];
 199         }
 200
 201         return NULL;
 202 }
 203
 204
 205 static void radius_msg_dump_attr(struct radius_attr_hdr *hdr)
 206 {
 207         struct radius_attr_type *attr;
 208         int i, len;
 209         unsigned char *pos;
 210
 211         attr = radius_get_attr_type(hdr->type);
 212
 213         printf("   Attribute %d (%s) length=%d\n",
 214                hdr->type, attr ? attr->name : "?Unknown?", hdr->length);
 215
 216         if (attr == NULL)
 217                 return;
 218
 219         len = hdr->length - sizeof(struct radius_attr_hdr);
 220         pos = (unsigned char *) (hdr + 1);
 221
 222         switch (attr->data_type) {
 223         case RADIUS_ATTR_TEXT:
 224                 printf("      Value: '");
 225                 for (i = 0; i < len; i++)
 226                         print_char(pos[i]);
 227                 printf("'\n");
 228                 break;
 229
 230         case RADIUS_ATTR_IP:
 231                 if (len == 4) {
 232                         struct in_addr *addr = (struct in_addr *) pos;
 233                         printf("      Value: %s\n", inet_ntoa(*addr));
 234                 } else
 235                         printf("      Invalid IP address length %d\n", len);
 236                 break;
 237
 238 #ifdef CONFIG_IPV6
 239         case RADIUS_ATTR_IPV6:
 240                 if (len == 16) {
 241                         char buf[128];
 242                         const char *atxt;
 243                         struct in6_addr *addr = (struct in6_addr *) pos;
 244                         atxt = inet_ntop(AF_INET6, addr, buf, sizeof(buf));
 245                         printf("      Value: %s\n", atxt ? atxt : "?");
 246                 } else
 247                         printf("      Invalid IPv6 address length %d\n", len);
 248                 break;
 249 #endif /* CONFIG_IPV6 */
 250
 251         case RADIUS_ATTR_HEXDUMP:
 252         case RADIUS_ATTR_UNDIST:
 253                 printf("      Value:");
 254                 for (i = 0; i < len; i++)
 255                         printf(" %02x", pos[i]);
 256                 printf("\n");
 257                 break;
 258
 259         case RADIUS_ATTR_INT32:
 260                 if (len == 4)
 261                         printf("      Value: %u\n", WPA_GET_BE32(pos));
 262                 else
 263                         printf("      Invalid INT32 length %d\n", len);
 264                 break;
 265
 266         default:
 267                 break;
 268         }
 269 }
 270
 271
 272 void radius_msg_dump(struct radius_msg *msg)
 273 {
 274         int i;
 275
 276         printf("RADIUS message: code=%d (%s) identifier=%d length=%d\n",
 277                msg->hdr->code, radius_code_string(msg->hdr->code),
 278                msg->hdr->identifier, ntohs(msg->hdr->length));
 279
 280         for (i = 0; i < msg->attr_used; i++) {
 281                 radius_msg_dump_attr(msg->attrs[i]);
 282         }
 283 }
 284
 285
 286 int radius_msg_finish(struct radius_msg *msg, u8 *secret, size_t secret_len)
 287 {
 288         if (secret) {
 289                 u8 auth[MD5_MAC_LEN];
 290                 struct radius_attr_hdr *attr;
 291
 292                 memset(auth, 0, MD5_MAC_LEN);
 293                 attr = radius_msg_add_attr(msg,
 294                                            RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
 295                                            auth, MD5_MAC_LEN);
 296                 if (attr == NULL) {
 297                         printf("WARNING: Could not add "
 298                                "Message-Authenticator\n");
 299                         return -1;
 300                 }
 301                 msg->hdr->length = htons(msg->buf_used);
 302                 hmac_md5(secret, secret_len, msg->buf, msg->buf_used,
 303                          (u8 *) (attr + 1));
 304         } else
 305                 msg->hdr->length = htons(msg->buf_used);
 306
 307         if (msg->buf_used > 0xffff) {
 308                 printf("WARNING: too long RADIUS message (%lu)\n",
 309                        (unsigned long) msg->buf_used);
 310                 return -1;
 311         }
 312         return 0;
 313 }
 314
 315
 316 int radius_msg_finish_srv(struct radius_msg *msg, const u8 *secret,
 317                           size_t secret_len, const u8 *req_authenticator)
 318 {
 319         u8 auth[MD5_MAC_LEN];
 320         struct radius_attr_hdr *attr;
 321         const u8 *addr[4];
 322         size_t len[4];
 323
 324         memset(auth, 0, MD5_MAC_LEN);
 325         attr = radius_msg_add_attr(msg, RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
 326                                    auth, MD5_MAC_LEN);
 327         if (attr == NULL) {
 328                 printf("WARNING: Could not add Message-Authenticator\n");
 329                 return -1;
 330         }
 331         msg->hdr->length = htons(msg->buf_used);
 332         memcpy(msg->hdr->authenticator, req_authenticator,
 333                sizeof(msg->hdr->authenticator));
 334         hmac_md5(secret, secret_len, msg->buf, msg->buf_used,
 335                  (u8 *) (attr + 1));
 336
 337         /* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
 338         addr[0] = (u8 *) msg->hdr;
 339         len[0] = 1 + 1 + 2;
 340         addr[1] = req_authenticator;
 341         len[1] = MD5_MAC_LEN;
 342         addr[2] = (u8 *) (msg->hdr + 1);
 343         len[2] = msg->buf_used - sizeof(*msg->hdr);
 344         addr[3] = secret;
 345         len[3] = secret_len;
 346         md5_vector(4, addr, len, msg->hdr->authenticator);
 347
 348         if (msg->buf_used > 0xffff) {
 349                 printf("WARNING: too long RADIUS message (%lu)\n",
 350                        (unsigned long) msg->buf_used);
 351                 return -1;
 352         }
 353         return 0;
 354 }
 355
 356
 357 void radius_msg_finish_acct(struct radius_msg *msg, u8 *secret,
 358                             size_t secret_len)
 359 {
 360         const u8 *addr[2];
 361         size_t len[2];
 362
 363         msg->hdr->length = htons(msg->buf_used);
 364         memset(msg->hdr->authenticator, 0, MD5_MAC_LEN);
 365         addr[0] = msg->buf;
 366         len[0] = msg->buf_used;
 367         addr[1] = secret;
 368         len[1] = secret_len;
 369         md5_vector(2, addr, len, msg->hdr->authenticator);
 370
 371         if (msg->buf_used > 0xffff) {
 372                 printf("WARNING: too long RADIUS messages (%lu)\n",
 373                        (unsigned long) msg->buf_used);
 374         }
 375 }
 376
 377
 378 static int radius_msg_add_attr_to_array(struct radius_msg *msg,
 379                                         struct radius_attr_hdr *attr)
 380 {
 381         if (msg->attr_used >= msg->attr_size) {
 382                 struct radius_attr_hdr **nattrs;
 383                 int nlen = msg->attr_size * 2;
 384
 385                 nattrs = (struct radius_attr_hdr **)
 386                         realloc(msg->attrs, nlen * sizeof(*msg->attrs));
 387
 388                 if (nattrs == NULL)
 389                         return -1;
 390
 391                 msg->attrs = nattrs;
 392                 msg->attr_size = nlen;
 393         }
 394
 395         msg->attrs[msg->attr_used++] = attr;
 396
 397         return 0;
 398 }
 399
 400
 401 struct radius_attr_hdr *radius_msg_add_attr(struct radius_msg *msg, u8 type,
 402                                             const u8 *data, size_t data_len)
 403 {
 404         size_t buf_needed;
 405         struct radius_attr_hdr *attr;
 406
 407         if (data_len > RADIUS_MAX_ATTR_LEN) {
 408                 printf("radius_msg_add_attr: too long attribute (%lu bytes)\n",
 409                        (unsigned long) data_len);
 410                 return NULL;
 411         }
 412
 413         buf_needed = msg->buf_used + sizeof(*attr) + data_len;
 414
 415         if (msg->buf_size < buf_needed) {
 416                 /* allocate more space for message buffer */
 417                 unsigned char *nbuf;
 418                 int nlen = msg->buf_size;
 419                 int diff, i;
 420
 421                 while (nlen < buf_needed)
 422                         nlen *= 2;
 423                 nbuf = (unsigned char *) realloc(msg->buf, nlen);
 424                 if (nbuf == NULL)
 425                         return NULL;
 426                 diff = nbuf - msg->buf;
 427                 msg->buf = nbuf;
 428                 msg->hdr = (struct radius_hdr *) msg->buf;
 429                 /* adjust attr pointers to match with the new buffer */
 430                 for (i = 0; i < msg->attr_used; i++)
 431                         msg->attrs[i] = (struct radius_attr_hdr *)
 432                                 (((u8 *) msg->attrs[i]) + diff);
 433                 memset(msg->buf + msg->buf_size, 0, nlen - msg->buf_size);
 434                 msg->buf_size = nlen;
 435         }
 436
 437         attr = (struct radius_attr_hdr *) (msg->buf + msg->buf_used);
 438         attr->type = type;
 439         attr->length = sizeof(*attr) + data_len;
 440         if (data_len > 0)
 441                 memcpy(attr + 1, data, data_len);
 442
 443         msg->buf_used += sizeof(*attr) + data_len;
 444
 445         if (radius_msg_add_attr_to_array(msg, attr))
 446                 return NULL;
 447
 448         return attr;
 449 }
 450
 451
 452 struct radius_msg *radius_msg_parse(const u8 *data, size_t len)
 453 {
 454         struct radius_msg *msg;
 455         struct radius_hdr *hdr;
 456         struct radius_attr_hdr *attr;
 457         size_t msg_len;
 458         unsigned char *pos, *end;
 459
 460         if (data == NULL || len < sizeof(*hdr))
 461                 return NULL;
 462
 463         hdr = (struct radius_hdr *) data;
 464
 465         msg_len = ntohs(hdr->length);
 466         if (msg_len < sizeof(*hdr) || msg_len > len) {
 467                 printf("Invalid RADIUS message length\n");
 468                 return NULL;
 469         }
 470
 471         if (msg_len < len) {
 472                 printf("Ignored %lu extra bytes after RADIUS message\n",
 473                        (unsigned long) len - msg_len);
 474         }
 475
 476         msg = (struct radius_msg *) malloc(sizeof(*msg));
 477         if (msg == NULL)
 478                 return NULL;
 479
 480         if (radius_msg_initialize(msg, msg_len)) {
 481                 free(msg);
 482                 return NULL;
 483         }
 484
 485         memcpy(msg->buf, data, msg_len);
 486         msg->buf_size = msg->buf_used = msg_len;
 487
 488         /* parse attributes */
 489         pos = (unsigned char *) (msg->hdr + 1);
 490         end = msg->buf + msg->buf_used;
 491         while (pos < end) {
 492                 if (end - pos < sizeof(*attr))
 493                         goto fail;
 494
 495                 attr = (struct radius_attr_hdr *) pos;
 496
 497                 if (pos + attr->length > end || attr->length < sizeof(*attr))
 498                         goto fail;
 499
 500                 /* TODO: check that attr->length is suitable for attr->type */
 501
 502                 if (radius_msg_add_attr_to_array(msg, attr))
 503                         goto fail;
 504
 505                 pos += attr->length;
 506         }
 507
 508         return msg;
 509
 510  fail:
 511         radius_msg_free(msg);
 512         free(msg);
 513         return NULL;
 514 }
 515
 516
 517 int radius_msg_add_eap(struct radius_msg *msg, const u8 *data, size_t data_len)
 518 {
 519         const u8 *pos = data;
 520         size_t left = data_len;
 521
 522         while (left > 0) {
 523                 int len;
 524                 if (left > RADIUS_MAX_ATTR_LEN)
 525                         len = RADIUS_MAX_ATTR_LEN;
 526                 else
 527                         len = left;
 528
 529                 if (!radius_msg_add_attr(msg, RADIUS_ATTR_EAP_MESSAGE,
 530                                          pos, len))
 531                         return 0;
 532
 533                 pos += len;
 534                 left -= len;
 535         }
 536
 537         return 1;
 538 }
 539
 540
 541 u8 *radius_msg_get_eap(struct radius_msg *msg, size_t *eap_len)
 542 {
 543         u8 *eap, *pos;
 544         size_t len;
 545         int i;
 546
 547         if (msg == NULL)
 548                 return NULL;
 549
 550         len = 0;
 551         for (i = 0; i < msg->attr_used; i++) {
 552                 if (msg->attrs[i]->type == RADIUS_ATTR_EAP_MESSAGE)
 553                         len += msg->attrs[i]->length -
 554                                 sizeof(struct radius_attr_hdr);
 555         }
 556
 557         if (len == 0)
 558                 return NULL;
 559
 560         eap = malloc(len);
 561         if (eap == NULL)
 562                 return NULL;
 563
 564         pos = eap;
 565         for (i = 0; i < msg->attr_used; i++) {
 566                 if (msg->attrs[i]->type == RADIUS_ATTR_EAP_MESSAGE) {
 567                         struct radius_attr_hdr *attr = msg->attrs[i];
 568                         int flen = attr->length - sizeof(*attr);
 569                         memcpy(pos, attr + 1, flen);
 570                         pos += flen;
 571                 }
 572         }
 573
 574         if (eap_len)
 575                 *eap_len = len;
 576
 577         return eap;
 578 }
 579
 580
 581 int radius_msg_verify_msg_auth(struct radius_msg *msg, const u8 *secret,
 582                                size_t secret_len, const u8 *req_auth)
 583 {
 584         u8 auth[MD5_MAC_LEN], orig[MD5_MAC_LEN];
 585         u8 orig_authenticator[16];
 586         struct radius_attr_hdr *attr = NULL;
 587         int i;
 588
 589         for (i = 0; i < msg->attr_used; i++) {
 590                 if (msg->attrs[i]->type == RADIUS_ATTR_MESSAGE_AUTHENTICATOR) {
 591                         if (attr != NULL) {
 592                                 printf("Multiple Message-Authenticator "
 593                                        "attributes in RADIUS message\n");
 594                                 return 1;
 595                         }
 596                         attr = msg->attrs[i];
 597                 }
 598         }
 599
 600         if (attr == NULL) {
 601                 printf("No Message-Authenticator attribute found\n");
 602                 return 1;
 603         }
 604
 605         memcpy(orig, attr + 1, MD5_MAC_LEN);
 606         memset(attr + 1, 0, MD5_MAC_LEN);
 607         if (req_auth) {
 608                 memcpy(orig_authenticator, msg->hdr->authenticator,
 609                        sizeof(orig_authenticator));
 610                 memcpy(msg->hdr->authenticator, req_auth,
 611                        sizeof(msg->hdr->authenticator));
 612         }
 613         hmac_md5(secret, secret_len, msg->buf, msg->buf_used, auth);
 614         memcpy(attr + 1, orig, MD5_MAC_LEN);
 615         if (req_auth) {
 616                 memcpy(msg->hdr->authenticator, orig_authenticator,
 617                        sizeof(orig_authenticator));
 618         }
 619
 620         if (memcmp(orig, auth, MD5_MAC_LEN) != 0) {
 621                 printf("Invalid Message-Authenticator!\n");
 622                 return 1;
 623         }
 624
 625         return 0;
 626 }
 627
 628
 629 int radius_msg_verify(struct radius_msg *msg, const u8 *secret,
 630                       size_t secret_len, struct radius_msg *sent_msg, int auth)
 631 {
 632         const u8 *addr[4];
 633         size_t len[4];
 634         u8 hash[MD5_MAC_LEN];
 635
 636         if (sent_msg == NULL) {
 637                 printf("No matching Access-Request message found\n");
 638                 return 1;
 639         }
 640
 641         if (auth &&
 642             radius_msg_verify_msg_auth(msg, secret, secret_len,
 643                                        sent_msg->hdr->authenticator)) {
 644                 return 1;
 645         }
 646
 647         /* ResponseAuth = MD5(Code+ID+Length+RequestAuth+Attributes+Secret) */
 648         addr[0] = (u8 *) msg->hdr;
 649         len[0] = 1 + 1 + 2;
 650         addr[1] = sent_msg->hdr->authenticator;
 651         len[1] = MD5_MAC_LEN;
 652         addr[2] = (u8 *) (msg->hdr + 1);
 653         len[2] = msg->buf_used - sizeof(*msg->hdr);
 654         addr[3] = secret;
 655         len[3] = secret_len;
 656         md5_vector(4, addr, len, hash);
 657         if (memcmp(hash, msg->hdr->authenticator, MD5_MAC_LEN) != 0) {
 658                 printf("Response Authenticator invalid!\n");
 659                 return 1;
 660         }
 661
 662         return 0;
 663
 664 }
 665
 666
 667 int radius_msg_copy_attr(struct radius_msg *dst, struct radius_msg *src,
 668                          u8 type)
 669 {
 670         struct radius_attr_hdr *attr = NULL;
 671         int i;
 672
 673         for (i = 0; i < src->attr_used; i++) {
 674                 if (src->attrs[i]->type == type) {
 675                         attr = src->attrs[i];
 676                         break;
 677                 }
 678         }
 679
 680         if (attr == NULL)
 681                 return 0;
 682
 683         if (!radius_msg_add_attr(dst, type, (u8 *) (attr + 1),
 684                                  attr->length - sizeof(*attr)))
 685                 return -1;
 686
 687         return 1;
 688 }
 689
 690
 691 /* Create Request Authenticator. The value should be unique over the lifetime
 692  * of the shared secret between authenticator and authentication server.
 693  * Use one-way MD5 hash calculated from current timestamp and some data given
 694  * by the caller. */
 695 void radius_msg_make_authenticator(struct radius_msg *msg,
 696                                    u8 *data, size_t len)
 697 {
 698         struct timeval tv;
 699         long int l;
 700         const u8 *addr[3];
 701         size_t elen[3];
 702
 703         gettimeofday(&tv, NULL);
 704         l = random();
 705         addr[0] = (u8 *) &tv;
 706         elen[0] = sizeof(tv);
 707         addr[1] = data;
 708         elen[1] = len;
 709         addr[2] = (u8 *) &l;
 710         elen[2] = sizeof(l);
 711         md5_vector(3, addr, elen, msg->hdr->authenticator);
 712 }
 713
 714
 715 /* Get Vendor-specific RADIUS Attribute from a parsed RADIUS message.
 716  * Returns the Attribute payload and sets alen to indicate the length of the
 717  * payload if a vendor attribute with subtype is found, otherwise returns NULL.
 718  * The returned payload is allocated with malloc() and caller must free it.
 719  */
 720 static u8 *radius_msg_get_vendor_attr(struct radius_msg *msg, u32 vendor,
 721                                       u8 subtype, size_t *alen)
 722 {
 723         u8 *data, *pos;
 724         int i;
 725         size_t len;
 726
 727         if (msg == NULL)
 728                 return NULL;
 729
 730         for (i = 0; i < msg->attr_used; i++) {
 731                 struct radius_attr_hdr *attr = msg->attrs[i];
 732                 int left;
 733                 u32 vendor_id;
 734                 struct radius_attr_vendor *vhdr;
 735
 736                 if (attr->type != RADIUS_ATTR_VENDOR_SPECIFIC)
 737                         continue;
 738
 739                 left = attr->length - sizeof(*attr);
 740                 if (left < 4)
 741                         continue;
 742
 743                 pos = (u8 *) (attr + 1);
 744
 745                 memcpy(&vendor_id, pos, 4);
 746                 pos += 4;
 747                 left -= 4;
 748
 749                 if (ntohl(vendor_id) != vendor)
 750                         continue;
 751
 752                 while (left >= sizeof(*vhdr)) {
 753                         vhdr = (struct radius_attr_vendor *) pos;
 754                         if (vhdr->vendor_length > left ||
 755                             vhdr->vendor_length < sizeof(*vhdr)) {
 756                                 left = 0;
 757                                 break;
 758                         }
 759                         if (vhdr->vendor_type != subtype) {
 760                                 pos += vhdr->vendor_length;
 761                                 left -= vhdr->vendor_length;
 762                                 continue;
 763                         }
 764
 765                         len = vhdr->vendor_length - sizeof(*vhdr);
 766                         data = malloc(len);
 767                         if (data == NULL)
 768                                 return NULL;
 769                         memcpy(data, pos + sizeof(*vhdr), len);
 770                         if (alen)
 771                                 *alen = len;
 772                         return data;
 773                 }
 774         }
 775
 776         return NULL;
 777 }
 778
 779
 780 static u8 * decrypt_ms_key(const u8 *key, size_t len,
 781                            const u8 *req_authenticator,
 782                            const u8 *secret, size_t secret_len, size_t *reslen)
 783 {
 784         u8 *plain, *ppos, *res;
 785         const u8 *pos;
 786         size_t left, plen;
 787         u8 hash[MD5_MAC_LEN];
 788         int i, first = 1;
 789         const u8 *addr[3];
 790         size_t elen[3];
 791
 792         /* key: 16-bit salt followed by encrypted key info */
 793
 794         if (len < 2 + 16)
 795                 return NULL;
 796
 797         pos = key + 2;
 798         left = len - 2;
 799         if (left % 16) {
 800                 printf("Invalid ms key len %lu\n", (unsigned long) left);
 801                 return NULL;
 802         }
 803
 804         plen = left;
 805         ppos = plain = malloc(plen);
 806         if (plain == NULL)
 807                 return NULL;
 808
 809         while (left > 0) {
 810                 /* b(1) = MD5(Secret + Request-Authenticator + Salt)
 811                  * b(i) = MD5(Secret + c(i - 1)) for i > 1 */
 812
 813                 addr[0] = secret;
 814                 elen[0] = secret_len;
 815                 if (first) {
 816                         addr[1] = req_authenticator;
 817                         elen[1] = MD5_MAC_LEN;
 818                         addr[2] = key;
 819                         elen[2] = 2; /* Salt */
 820                 } else {
 821                         addr[1] = pos - MD5_MAC_LEN;
 822                         elen[1] = MD5_MAC_LEN;
 823                 }
 824                 md5_vector(first ? 3 : 2, addr, elen, hash);
 825                 first = 0;
 826
 827                 for (i = 0; i < MD5_MAC_LEN; i++)
 828                         *ppos++ = *pos++ ^ hash[i];
 829                 left -= MD5_MAC_LEN;
 830         }
 831
 832         if (plain[0] > plen - 1) {
 833                 printf("Failed to decrypt MPPE key\n");
 834                 free(plain);
 835                 return NULL;
 836         }
 837
 838         res = malloc(plain[0]);
 839         if (res == NULL) {
 840                 free(plain);
 841                 return NULL;
 842         }
 843         memcpy(res, plain + 1, plain[0]);
 844         if (reslen)
 845                 *reslen = plain[0];
 846         free(plain);
 847         return res;
 848 }
 849
 850
 851 static void encrypt_ms_key(const u8 *key, size_t key_len, u16 salt,
 852                            const u8 *req_authenticator,
 853                            const u8 *secret, size_t secret_len,
 854                            u8 *ebuf, size_t *elen)
 855 {
 856         int i, len, first = 1;
 857         u8 hash[MD5_MAC_LEN], saltbuf[2], *pos;
 858         const u8 *addr[3];
 859         size_t _len[3];
 860
 861         saltbuf[0] = salt >> 8;
 862         saltbuf[1] = salt;
 863
 864         len = 1 + key_len;
 865         if (len & 0x0f) {
 866                 len = (len & 0xf0) + 16;
 867         }
 868         memset(ebuf, 0, len);
 869         ebuf[0] = key_len;
 870         memcpy(ebuf + 1, key, key_len);
 871
 872         *elen = len;
 873
 874         pos = ebuf;
 875         while (len > 0) {
 876                 /* b(1) = MD5(Secret + Request-Authenticator + Salt)
 877                  * b(i) = MD5(Secret + c(i - 1)) for i > 1 */
 878                 addr[0] = secret;
 879                 _len[0] = secret_len;
 880                 if (first) {
 881                         addr[1] = req_authenticator;
 882                         _len[1] = MD5_MAC_LEN;
 883                         addr[2] = saltbuf;
 884                         _len[2] = sizeof(saltbuf);
 885                 } else {
 886                         addr[1] = pos - MD5_MAC_LEN;
 887                         _len[1] = MD5_MAC_LEN;
 888                 }
 889                 md5_vector(first ? 3 : 2, addr, _len, hash);
 890                 first = 0;
 891
 892                 for (i = 0; i < MD5_MAC_LEN; i++)
 893                         *pos++ ^= hash[i];
 894
 895                 len -= MD5_MAC_LEN;
 896         }
 897 }
 898
 899
 900 struct radius_ms_mppe_keys *
 901 radius_msg_get_ms_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
 902                        u8 *secret, size_t secret_len)
 903 {
 904         u8 *key;
 905         size_t keylen;
 906         struct radius_ms_mppe_keys *keys;
 907
 908         if (msg == NULL || sent_msg == NULL)
 909                 return NULL;
 910
 911         keys = (struct radius_ms_mppe_keys *) malloc(sizeof(*keys));
 912         if (keys == NULL)
 913                 return NULL;
 914
 915         memset(keys, 0, sizeof(*keys));
 916
 917         key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_MICROSOFT,
 918                                          RADIUS_VENDOR_ATTR_MS_MPPE_SEND_KEY,
 919                                          &keylen);
 920         if (key) {
 921                 keys->send = decrypt_ms_key(key, keylen,
 922                                             sent_msg->hdr->authenticator,
 923                                             secret, secret_len,
 924                                             &keys->send_len);
 925                 free(key);
 926         }
 927
 928         key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_MICROSOFT,
 929                                          RADIUS_VENDOR_ATTR_MS_MPPE_RECV_KEY,
 930                                          &keylen);
 931         if (key) {
 932                 keys->recv = decrypt_ms_key(key, keylen,
 933                                             sent_msg->hdr->authenticator,
 934                                             secret, secret_len,
 935                                             &keys->recv_len);
 936                 free(key);
 937         }
 938
 939         return keys;
 940 }
 941
 942
 943 struct radius_ms_mppe_keys *
 944 radius_msg_get_cisco_keys(struct radius_msg *msg, struct radius_msg *sent_msg,
 945                           u8 *secret, size_t secret_len)
 946 {
 947         u8 *key;
 948         size_t keylen;
 949         struct radius_ms_mppe_keys *keys;
 950
 951         if (msg == NULL || sent_msg == NULL)
 952                 return NULL;
 953
 954         keys = (struct radius_ms_mppe_keys *) malloc(sizeof(*keys));
 955         if (keys == NULL)
 956                 return NULL;
 957
 958         memset(keys, 0, sizeof(*keys));
 959
 960         key = radius_msg_get_vendor_attr(msg, RADIUS_VENDOR_ID_CISCO,
 961                                          RADIUS_CISCO_AV_PAIR, &keylen);
 962         if (key && keylen == 51 && memcmp(key, "leap:session-key=", 17) == 0) {
 963                 keys->recv = decrypt_ms_key(key + 17, keylen - 17,
 964                                             sent_msg->hdr->authenticator,
 965                                             secret, secret_len,
 966                                             &keys->recv_len);
 967         }
 968         free(key);
 969
 970         return keys;
 971 }
 972
 973
 974 int radius_msg_add_mppe_keys(struct radius_msg *msg,
 975                              const u8 *req_authenticator,
 976                              const u8 *secret, size_t secret_len,
 977                              const u8 *send_key, size_t send_key_len,
 978                              const u8 *recv_key, size_t recv_key_len)
 979 {
 980         struct radius_attr_hdr *attr;
 981         u32 vendor_id = htonl(RADIUS_VENDOR_ID_MICROSOFT);
 982         u8 *buf;
 983         struct radius_attr_vendor *vhdr;
 984         u8 *pos;
 985         size_t elen;
 986         int hlen;
 987         u16 salt;
 988
 989         hlen = sizeof(vendor_id) + sizeof(*vhdr) + 2;
 990
 991         /* MS-MPPE-Send-Key */
 992         buf = malloc(hlen + send_key_len + 16);
 993         if (buf == NULL) {
 994                 return 0;
 995         }
 996         pos = buf;
 997         memcpy(pos, &vendor_id, sizeof(vendor_id));
 998         pos += sizeof(vendor_id);
 999         vhdr = (struct radius_attr_vendor *) pos;
1000         vhdr->vendor_type = RADIUS_VENDOR_ATTR_MS_MPPE_SEND_KEY;
1001         pos = (u8 *) (vhdr + 1);
1002         salt = random() | 0x8000;
1003         *pos++ = salt >> 8;
1004         *pos++ = salt;
1005         encrypt_ms_key(send_key, send_key_len, salt, req_authenticator, secret,
1006                        secret_len, pos, &elen);
1007         vhdr->vendor_length = hlen + elen - sizeof(vendor_id);
1008
1009         attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
1010                                    buf, hlen + elen);
1011         free(buf);
1012         if (attr == NULL) {
1013                 return 0;
1014         }
1015
1016         /* MS-MPPE-Recv-Key */
1017         buf = malloc(hlen + send_key_len + 16);
1018         if (buf == NULL) {
1019                 return 0;
1020         }
1021         pos = buf;
1022         memcpy(pos, &vendor_id, sizeof(vendor_id));
1023         pos += sizeof(vendor_id);
1024         vhdr = (struct radius_attr_vendor *) pos;
1025         vhdr->vendor_type = RADIUS_VENDOR_ATTR_MS_MPPE_RECV_KEY;
1026         pos = (u8 *) (vhdr + 1);
1027         salt ^= 1;
1028         *pos++ = salt >> 8;
1029         *pos++ = salt;
1030         encrypt_ms_key(recv_key, recv_key_len, salt, req_authenticator, secret,
1031                        secret_len, pos, &elen);
1032         vhdr->vendor_length = hlen + elen - sizeof(vendor_id);
1033
1034         attr = radius_msg_add_attr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
1035                                    buf, hlen + elen);
1036         free(buf);
1037         if (attr == NULL) {
1038                 return 0;
1039         }
1040
1041         return 1;
1042 }
1043
1044
1045 /* Add User-Password attribute to a RADIUS message and encrypt it as specified
1046  * in RFC 2865, Chap. 5.2 */
1047 struct radius_attr_hdr *
1048 radius_msg_add_attr_user_password(struct radius_msg *msg,
1049                                   u8 *data, size_t data_len,
1050                                   u8 *secret, size_t secret_len)
1051 {
1052         u8 buf[128];
1053         int padlen, i, pos;
1054         size_t buf_len;
1055         const u8 *addr[2];
1056         size_t len[2];
1057         u8 hash[16];
1058
1059         if (data_len > 128)
1060                 return NULL;
1061
1062         memcpy(buf, data, data_len);
1063         buf_len = data_len;
1064
1065         padlen = data_len % 16;
1066         if (padlen) {
1067                 padlen = 16 - padlen;
1068                 memset(buf + data_len, 0, padlen);
1069                 buf_len += padlen;
1070         }
1071
1072         addr[0] = secret;
1073         len[0] = secret_len;
1074         addr[1] = msg->hdr->authenticator;
1075         len[1] = 16;
1076         md5_vector(2, addr, len, hash);
1077
1078         for (i = 0; i < 16; i++)
1079                 buf[i] ^= hash[i];
1080         pos = 16;
1081
1082         while (pos < buf_len) {
1083                 addr[0] = secret;
1084                 len[0] = secret_len;
1085                 addr[1] = &buf[pos - 16];
1086                 len[1] = 16;
1087                 md5_vector(2, addr, len, hash);
1088
1089                 for (i = 0; i < 16; i++)
1090                         buf[pos + i] ^= hash[i];
1091
1092                 pos += 16;
1093         }
1094
1095         return radius_msg_add_attr(msg, RADIUS_ATTR_USER_PASSWORD,
1096                                    buf, buf_len);
1097 }
1098
1099
1100 int radius_msg_get_attr(struct radius_msg *msg, u8 type, u8 *buf, size_t len)
1101 {
1102         int i;
1103         struct radius_attr_hdr *attr = NULL;
1104         size_t dlen;
1105
1106         for (i = 0; i < msg->attr_used; i++) {
1107                 if (msg->attrs[i]->type == type) {
1108                         attr = msg->attrs[i];
1109                         break;
1110                 }
1111         }
1112
1113         if (!attr)
1114                 return -1;
1115
1116         dlen = attr->length - sizeof(*attr);
1117         if (buf)
1118                 memcpy(buf, (attr + 1), dlen > len ? len : dlen);
1119         return dlen;
1120 }
1121
1122
1123 int radius_msg_get_attr_ptr(struct radius_msg *msg, u8 type, u8 **buf,
1124                             size_t *len, const u8 *start)
1125 {
1126         int i;
1127         struct radius_attr_hdr *attr = NULL;
1128
1129         for (i = 0; i < msg->attr_used; i++) {
1130                 if (msg->attrs[i]->type == type &&
1131                     (start == NULL || (u8 *) msg->attrs[i] > start)) {
1132                         attr = msg->attrs[i];
1133                         break;
1134                 }
1135         }
1136
1137         if (!attr)
1138                 return -1;
1139
1140         *buf = (u8 *) (attr + 1);
1141         *len = attr->length - sizeof(*attr);
1142         return 0;
1143 }
1144
1145
1146 int radius_msg_count_attr(struct radius_msg *msg, u8 type, int min_len)
1147 {
1148         int i, count;
1149
1150         for (count = 0, i = 0; i < msg->attr_used; i++) {
1151                 if (msg->attrs[i]->type == type &&
1152                     msg->attrs[i]->length >=
1153                     sizeof(struct radius_attr_hdr) + min_len)
1154                         count++;
1155         }
1156
1157         return count;
1158 }