contrib/hostapd/src/tls/tlsv1_server.c

   1 /*
   2  * TLSv1 server (RFC 2246)
   3  * Copyright (c) 2006-2007, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "sha1.h"
  19 #include "tls.h"
  20 #include "tlsv1_common.h"
  21 #include "tlsv1_record.h"
  22 #include "tlsv1_server.h"
  23 #include "tlsv1_server_i.h"
  24
  25 /* TODO:
  26  * Support for a message fragmented across several records (RFC 2246, 6.2.1)
  27  */
  28
  29
  30 void tlsv1_server_alert(struct tlsv1_server *conn, u8 level, u8 description)
  31 {
  32         conn->alert_level = level;
  33         conn->alert_description = description;
  34 }
  35
  36
  37 int tlsv1_server_derive_keys(struct tlsv1_server *conn,
  38                              const u8 *pre_master_secret,
  39                              size_t pre_master_secret_len)
  40 {
  41         u8 seed[2 * TLS_RANDOM_LEN];
  42         u8 key_block[TLS_MAX_KEY_BLOCK_LEN];
  43         u8 *pos;
  44         size_t key_block_len;
  45
  46         if (pre_master_secret) {
  47                 wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: pre_master_secret",
  48                                 pre_master_secret, pre_master_secret_len);
  49                 os_memcpy(seed, conn->client_random, TLS_RANDOM_LEN);
  50                 os_memcpy(seed + TLS_RANDOM_LEN, conn->server_random,
  51                           TLS_RANDOM_LEN);
  52                 if (tls_prf(pre_master_secret, pre_master_secret_len,
  53                             "master secret", seed, 2 * TLS_RANDOM_LEN,
  54                             conn->master_secret, TLS_MASTER_SECRET_LEN)) {
  55                         wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive "
  56                                    "master_secret");
  57                         return -1;
  58                 }
  59                 wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: master_secret",
  60                                 conn->master_secret, TLS_MASTER_SECRET_LEN);
  61         }
  62
  63         os_memcpy(seed, conn->server_random, TLS_RANDOM_LEN);
  64         os_memcpy(seed + TLS_RANDOM_LEN, conn->client_random, TLS_RANDOM_LEN);
  65         key_block_len = 2 * (conn->rl.hash_size + conn->rl.key_material_len +
  66                              conn->rl.iv_size);
  67         if (tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
  68                     "key expansion", seed, 2 * TLS_RANDOM_LEN,
  69                     key_block, key_block_len)) {
  70                 wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive key_block");
  71                 return -1;
  72         }
  73         wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: key_block",
  74                         key_block, key_block_len);
  75
  76         pos = key_block;
  77
  78         /* client_write_MAC_secret */
  79         os_memcpy(conn->rl.read_mac_secret, pos, conn->rl.hash_size);
  80         pos += conn->rl.hash_size;
  81         /* server_write_MAC_secret */
  82         os_memcpy(conn->rl.write_mac_secret, pos, conn->rl.hash_size);
  83         pos += conn->rl.hash_size;
  84
  85         /* client_write_key */
  86         os_memcpy(conn->rl.read_key, pos, conn->rl.key_material_len);
  87         pos += conn->rl.key_material_len;
  88         /* server_write_key */
  89         os_memcpy(conn->rl.write_key, pos, conn->rl.key_material_len);
  90         pos += conn->rl.key_material_len;
  91
  92         /* client_write_IV */
  93         os_memcpy(conn->rl.read_iv, pos, conn->rl.iv_size);
  94         pos += conn->rl.iv_size;
  95         /* server_write_IV */
  96         os_memcpy(conn->rl.write_iv, pos, conn->rl.iv_size);
  97         pos += conn->rl.iv_size;
  98
  99         return 0;
 100 }
 101
 102
 103 /**
 104  * tlsv1_server_handshake - Process TLS handshake
 105  * @conn: TLSv1 server connection data from tlsv1_server_init()
 106  * @in_data: Input data from TLS peer
 107  * @in_len: Input data length
 108  * @out_len: Length of the output buffer.
 109  * Returns: Pointer to output data, %NULL on failure
 110  */
 111 u8 * tlsv1_server_handshake(struct tlsv1_server *conn,
 112                             const u8 *in_data, size_t in_len,
 113                             size_t *out_len)
 114 {
 115         const u8 *pos, *end;
 116         u8 *msg = NULL, *in_msg, *in_pos, *in_end, alert, ct;
 117         size_t in_msg_len;
 118
 119         if (in_data == NULL || in_len == 0) {
 120                 wpa_printf(MSG_DEBUG, "TLSv1: No input data to server");
 121                 return NULL;
 122         }
 123
 124         pos = in_data;
 125         end = in_data + in_len;
 126         in_msg = os_malloc(in_len);
 127         if (in_msg == NULL)
 128                 return NULL;
 129
 130         /* Each received packet may include multiple records */
 131         while (pos < end) {
 132                 in_msg_len = in_len;
 133                 if (tlsv1_record_receive(&conn->rl, pos, end - pos,
 134                                          in_msg, &in_msg_len, &alert)) {
 135                         wpa_printf(MSG_DEBUG, "TLSv1: Processing received "
 136                                    "record failed");
 137                         tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
 138                         goto failed;
 139                 }
 140                 ct = pos[0];
 141
 142                 in_pos = in_msg;
 143                 in_end = in_msg + in_msg_len;
 144
 145                 /* Each received record may include multiple messages of the
 146                  * same ContentType. */
 147                 while (in_pos < in_end) {
 148                         in_msg_len = in_end - in_pos;
 149                         if (tlsv1_server_process_handshake(conn, ct, in_pos,
 150                                                            &in_msg_len) < 0)
 151                                 goto failed;
 152                         in_pos += in_msg_len;
 153                 }
 154
 155                 pos += TLS_RECORD_HEADER_LEN + WPA_GET_BE16(pos + 3);
 156         }
 157
 158         os_free(in_msg);
 159         in_msg = NULL;
 160
 161         msg = tlsv1_server_handshake_write(conn, out_len);
 162
 163 failed:
 164         os_free(in_msg);
 165         if (conn->alert_level) {
 166                 if (conn->state == FAILED) {
 167                         /* Avoid alert loops */
 168                         wpa_printf(MSG_DEBUG, "TLSv1: Drop alert loop");
 169                         os_free(msg);
 170                         return NULL;
 171                 }
 172                 conn->state = FAILED;
 173                 os_free(msg);
 174                 msg = tlsv1_server_send_alert(conn, conn->alert_level,
 175                                               conn->alert_description,
 176                                               out_len);
 177         }
 178
 179         return msg;
 180 }
 181
 182
 183 /**
 184  * tlsv1_server_encrypt - Encrypt data into TLS tunnel
 185  * @conn: TLSv1 server connection data from tlsv1_server_init()
 186  * @in_data: Pointer to plaintext data to be encrypted
 187  * @in_len: Input buffer length
 188  * @out_data: Pointer to output buffer (encrypted TLS data)
 189  * @out_len: Maximum out_data length
 190  * Returns: Number of bytes written to out_data, -1 on failure
 191  *
 192  * This function is used after TLS handshake has been completed successfully to
 193  * send data in the encrypted tunnel.
 194  */
 195 int tlsv1_server_encrypt(struct tlsv1_server *conn,
 196                          const u8 *in_data, size_t in_len,
 197                          u8 *out_data, size_t out_len)
 198 {
 199         size_t rlen;
 200
 201         wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Plaintext AppData",
 202                         in_data, in_len);
 203
 204         os_memcpy(out_data + TLS_RECORD_HEADER_LEN, in_data, in_len);
 205
 206         if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_APPLICATION_DATA,
 207                               out_data, out_len, in_len, &rlen) < 0) {
 208                 wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
 209                 tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
 210                                    TLS_ALERT_INTERNAL_ERROR);
 211                 return -1;
 212         }
 213
 214         return rlen;
 215 }
 216
 217
 218 /**
 219  * tlsv1_server_decrypt - Decrypt data from TLS tunnel
 220  * @conn: TLSv1 server connection data from tlsv1_server_init()
 221  * @in_data: Pointer to input buffer (encrypted TLS data)
 222  * @in_len: Input buffer length
 223  * @out_data: Pointer to output buffer (decrypted data from TLS tunnel)
 224  * @out_len: Maximum out_data length
 225  * Returns: Number of bytes written to out_data, -1 on failure
 226  *
 227  * This function is used after TLS handshake has been completed successfully to
 228  * receive data from the encrypted tunnel.
 229  */
 230 int tlsv1_server_decrypt(struct tlsv1_server *conn,
 231                          const u8 *in_data, size_t in_len,
 232                          u8 *out_data, size_t out_len)
 233 {
 234         const u8 *in_end, *pos;
 235         int res;
 236         u8 alert, *out_end, *out_pos;
 237         size_t olen;
 238
 239         pos = in_data;
 240         in_end = in_data + in_len;
 241         out_pos = out_data;
 242         out_end = out_data + out_len;
 243
 244         while (pos < in_end) {
 245                 if (pos[0] != TLS_CONTENT_TYPE_APPLICATION_DATA) {
 246                         wpa_printf(MSG_DEBUG, "TLSv1: Unexpected content type "
 247                                    "0x%x", pos[0]);
 248                         tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
 249                                            TLS_ALERT_UNEXPECTED_MESSAGE);
 250                         return -1;
 251                 }
 252
 253                 olen = out_end - out_pos;
 254                 res = tlsv1_record_receive(&conn->rl, pos, in_end - pos,
 255                                            out_pos, &olen, &alert);
 256                 if (res < 0) {
 257                         wpa_printf(MSG_DEBUG, "TLSv1: Record layer processing "
 258                                    "failed");
 259                         tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
 260                         return -1;
 261                 }
 262                 out_pos += olen;
 263                 if (out_pos > out_end) {
 264                         wpa_printf(MSG_DEBUG, "TLSv1: Buffer not large enough "
 265                                    "for processing the received record");
 266                         tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
 267                                            TLS_ALERT_INTERNAL_ERROR);
 268                         return -1;
 269                 }
 270
 271                 pos += TLS_RECORD_HEADER_LEN + WPA_GET_BE16(pos + 3);
 272         }
 273
 274         return out_pos - out_data;
 275 }
 276
 277
 278 /**
 279  * tlsv1_server_global_init - Initialize TLSv1 server
 280  * Returns: 0 on success, -1 on failure
 281  *
 282  * This function must be called before using any other TLSv1 server functions.
 283  */
 284 int tlsv1_server_global_init(void)
 285 {
 286         return crypto_global_init();
 287 }
 288
 289
 290 /**
 291  * tlsv1_server_global_deinit - Deinitialize TLSv1 server
 292  *
 293  * This function can be used to deinitialize the TLSv1 server that was
 294  * initialized by calling tlsv1_server_global_init(). No TLSv1 server functions
 295  * can be called after this before calling tlsv1_server_global_init() again.
 296  */
 297 void tlsv1_server_global_deinit(void)
 298 {
 299         crypto_global_deinit();
 300 }
 301
 302
 303 /**
 304  * tlsv1_server_init - Initialize TLSv1 server connection
 305  * @cred: Pointer to server credentials from tlsv1_server_cred_alloc()
 306  * Returns: Pointer to TLSv1 server connection data or %NULL on failure
 307  */
 308 struct tlsv1_server * tlsv1_server_init(struct tlsv1_credentials *cred)
 309 {
 310         struct tlsv1_server *conn;
 311         size_t count;
 312         u16 *suites;
 313
 314         conn = os_zalloc(sizeof(*conn));
 315         if (conn == NULL)
 316                 return NULL;
 317
 318         conn->cred = cred;
 319
 320         conn->state = CLIENT_HELLO;
 321
 322         if (tls_verify_hash_init(&conn->verify) < 0) {
 323                 wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize verify "
 324                            "hash");
 325                 os_free(conn);
 326                 return NULL;
 327         }
 328
 329         count = 0;
 330         suites = conn->cipher_suites;
 331 #ifndef CONFIG_CRYPTO_INTERNAL
 332         suites[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
 333 #endif /* CONFIG_CRYPTO_INTERNAL */
 334         suites[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
 335         suites[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
 336         suites[count++] = TLS_RSA_WITH_RC4_128_SHA;
 337         suites[count++] = TLS_RSA_WITH_RC4_128_MD5;
 338         conn->num_cipher_suites = count;
 339
 340         return conn;
 341 }
 342
 343
 344 static void tlsv1_server_clear_data(struct tlsv1_server *conn)
 345 {
 346         tlsv1_record_set_cipher_suite(&conn->rl, TLS_NULL_WITH_NULL_NULL);
 347         tlsv1_record_change_write_cipher(&conn->rl);
 348         tlsv1_record_change_read_cipher(&conn->rl);
 349         tls_verify_hash_free(&conn->verify);
 350
 351         crypto_public_key_free(conn->client_rsa_key);
 352         conn->client_rsa_key = NULL;
 353
 354         os_free(conn->session_ticket);
 355         conn->session_ticket = NULL;
 356         conn->session_ticket_len = 0;
 357         conn->use_session_ticket = 0;
 358
 359         os_free(conn->dh_secret);
 360         conn->dh_secret = NULL;
 361         conn->dh_secret_len = 0;
 362 }
 363
 364
 365 /**
 366  * tlsv1_server_deinit - Deinitialize TLSv1 server connection
 367  * @conn: TLSv1 server connection data from tlsv1_server_init()
 368  */
 369 void tlsv1_server_deinit(struct tlsv1_server *conn)
 370 {
 371         tlsv1_server_clear_data(conn);
 372         os_free(conn);
 373 }
 374
 375
 376 /**
 377  * tlsv1_server_established - Check whether connection has been established
 378  * @conn: TLSv1 server connection data from tlsv1_server_init()
 379  * Returns: 1 if connection is established, 0 if not
 380  */
 381 int tlsv1_server_established(struct tlsv1_server *conn)
 382 {
 383         return conn->state == ESTABLISHED;
 384 }
 385
 386
 387 /**
 388  * tlsv1_server_prf - Use TLS-PRF to derive keying material
 389  * @conn: TLSv1 server connection data from tlsv1_server_init()
 390  * @label: Label (e.g., description of the key) for PRF
 391  * @server_random_first: seed is 0 = client_random|server_random,
 392  * 1 = server_random|client_random
 393  * @out: Buffer for output data from TLS-PRF
 394  * @out_len: Length of the output buffer
 395  * Returns: 0 on success, -1 on failure
 396  */
 397 int tlsv1_server_prf(struct tlsv1_server *conn, const char *label,
 398                      int server_random_first, u8 *out, size_t out_len)
 399 {
 400         u8 seed[2 * TLS_RANDOM_LEN];
 401
 402         if (conn->state != ESTABLISHED)
 403                 return -1;
 404
 405         if (server_random_first) {
 406                 os_memcpy(seed, conn->server_random, TLS_RANDOM_LEN);
 407                 os_memcpy(seed + TLS_RANDOM_LEN, conn->client_random,
 408                           TLS_RANDOM_LEN);
 409         } else {
 410                 os_memcpy(seed, conn->client_random, TLS_RANDOM_LEN);
 411                 os_memcpy(seed + TLS_RANDOM_LEN, conn->server_random,
 412                           TLS_RANDOM_LEN);
 413         }
 414
 415         return tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
 416                        label, seed, 2 * TLS_RANDOM_LEN, out, out_len);
 417 }
 418
 419
 420 /**
 421  * tlsv1_server_get_cipher - Get current cipher name
 422  * @conn: TLSv1 server connection data from tlsv1_server_init()
 423  * @buf: Buffer for the cipher name
 424  * @buflen: buf size
 425  * Returns: 0 on success, -1 on failure
 426  *
 427  * Get the name of the currently used cipher.
 428  */
 429 int tlsv1_server_get_cipher(struct tlsv1_server *conn, char *buf,
 430                             size_t buflen)
 431 {
 432         char *cipher;
 433
 434         switch (conn->rl.cipher_suite) {
 435         case TLS_RSA_WITH_RC4_128_MD5:
 436                 cipher = "RC4-MD5";
 437                 break;
 438         case TLS_RSA_WITH_RC4_128_SHA:
 439                 cipher = "RC4-SHA";
 440                 break;
 441         case TLS_RSA_WITH_DES_CBC_SHA:
 442                 cipher = "DES-CBC-SHA";
 443                 break;
 444         case TLS_RSA_WITH_3DES_EDE_CBC_SHA:
 445                 cipher = "DES-CBC3-SHA";
 446                 break;
 447         case TLS_DH_anon_WITH_AES_128_CBC_SHA:
 448                 cipher = "ADH-AES-128-SHA";
 449                 break;
 450         case TLS_RSA_WITH_AES_256_CBC_SHA:
 451                 cipher = "AES-256-SHA";
 452                 break;
 453         case TLS_RSA_WITH_AES_128_CBC_SHA:
 454                 cipher = "AES-128-SHA";
 455                 break;
 456         default:
 457                 return -1;
 458         }
 459
 460         if (os_strlcpy(buf, cipher, buflen) >= buflen)
 461                 return -1;
 462         return 0;
 463 }
 464
 465
 466 /**
 467  * tlsv1_server_shutdown - Shutdown TLS connection
 468  * @conn: TLSv1 server connection data from tlsv1_server_init()
 469  * Returns: 0 on success, -1 on failure
 470  */
 471 int tlsv1_server_shutdown(struct tlsv1_server *conn)
 472 {
 473         conn->state = CLIENT_HELLO;
 474
 475         if (tls_verify_hash_init(&conn->verify) < 0) {
 476                 wpa_printf(MSG_DEBUG, "TLSv1: Failed to re-initialize verify "
 477                            "hash");
 478                 return -1;
 479         }
 480
 481         tlsv1_server_clear_data(conn);
 482
 483         return 0;
 484 }
 485
 486
 487 /**
 488  * tlsv1_server_resumed - Was session resumption used
 489  * @conn: TLSv1 server connection data from tlsv1_server_init()
 490  * Returns: 1 if current session used session resumption, 0 if not
 491  */
 492 int tlsv1_server_resumed(struct tlsv1_server *conn)
 493 {
 494         return 0;
 495 }
 496
 497
 498 /**
 499  * tlsv1_server_get_keys - Get master key and random data from TLS connection
 500  * @conn: TLSv1 server connection data from tlsv1_server_init()
 501  * @keys: Structure of key/random data (filled on success)
 502  * Returns: 0 on success, -1 on failure
 503  */
 504 int tlsv1_server_get_keys(struct tlsv1_server *conn, struct tls_keys *keys)
 505 {
 506         os_memset(keys, 0, sizeof(*keys));
 507         if (conn->state == CLIENT_HELLO)
 508                 return -1;
 509
 510         keys->client_random = conn->client_random;
 511         keys->client_random_len = TLS_RANDOM_LEN;
 512
 513         if (conn->state != SERVER_HELLO) {
 514                 keys->server_random = conn->server_random;
 515                 keys->server_random_len = TLS_RANDOM_LEN;
 516                 keys->master_key = conn->master_secret;
 517                 keys->master_key_len = TLS_MASTER_SECRET_LEN;
 518         }
 519
 520         return 0;
 521 }
 522
 523
 524 /**
 525  * tlsv1_server_get_keyblock_size - Get TLS key_block size
 526  * @conn: TLSv1 server connection data from tlsv1_server_init()
 527  * Returns: Size of the key_block for the negotiated cipher suite or -1 on
 528  * failure
 529  */
 530 int tlsv1_server_get_keyblock_size(struct tlsv1_server *conn)
 531 {
 532         if (conn->state == CLIENT_HELLO || conn->state == SERVER_HELLO)
 533                 return -1;
 534
 535         return 2 * (conn->rl.hash_size + conn->rl.key_material_len +
 536                     conn->rl.iv_size);
 537 }
 538
 539
 540 /**
 541  * tlsv1_server_set_cipher_list - Configure acceptable cipher suites
 542  * @conn: TLSv1 server connection data from tlsv1_server_init()
 543  * @ciphers: Zero (TLS_CIPHER_NONE) terminated list of allowed ciphers
 544  * (TLS_CIPHER_*).
 545  * Returns: 0 on success, -1 on failure
 546  */
 547 int tlsv1_server_set_cipher_list(struct tlsv1_server *conn, u8 *ciphers)
 548 {
 549 #ifdef EAP_FAST
 550         size_t count;
 551         u16 *suites;
 552
 553         /* TODO: implement proper configuration of cipher suites */
 554         if (ciphers[0] == TLS_CIPHER_ANON_DH_AES128_SHA) {
 555                 count = 0;
 556                 suites = conn->cipher_suites;
 557 #ifndef CONFIG_CRYPTO_INTERNAL
 558                 suites[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
 559 #endif /* CONFIG_CRYPTO_INTERNAL */
 560                 suites[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
 561                 suites[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
 562                 suites[count++] = TLS_RSA_WITH_RC4_128_SHA;
 563                 suites[count++] = TLS_RSA_WITH_RC4_128_MD5;
 564 #ifndef CONFIG_CRYPTO_INTERNAL
 565                 suites[count++] = TLS_DH_anon_WITH_AES_256_CBC_SHA;
 566 #endif /* CONFIG_CRYPTO_INTERNAL */
 567                 suites[count++] = TLS_DH_anon_WITH_AES_128_CBC_SHA;
 568                 suites[count++] = TLS_DH_anon_WITH_3DES_EDE_CBC_SHA;
 569                 suites[count++] = TLS_DH_anon_WITH_RC4_128_MD5;
 570                 suites[count++] = TLS_DH_anon_WITH_DES_CBC_SHA;
 571                 conn->num_cipher_suites = count;
 572         }
 573
 574         return 0;
 575 #else /* EAP_FAST */
 576         return -1;
 577 #endif /* EAP_FAST */
 578 }
 579
 580
 581 int tlsv1_server_set_verify(struct tlsv1_server *conn, int verify_peer)
 582 {
 583         conn->verify_peer = verify_peer;
 584         return 0;
 585 }
 586
 587
 588 void tlsv1_server_set_session_ticket_cb(struct tlsv1_server *conn,
 589                                         tlsv1_server_session_ticket_cb cb,
 590                                         void *ctx)
 591 {
 592         wpa_printf(MSG_DEBUG, "TLSv1: SessionTicket callback set %p (ctx %p)",
 593                    cb, ctx);
 594         conn->session_ticket_cb = cb;
 595         conn->session_ticket_cb_ctx = ctx;
 596 }