1 /* 2 * Copyright 2023-2025 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the Apache License 2.0 (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include "internal/quic_port.h" 11 #include "internal/quic_channel.h" 12 #include "internal/quic_lcidm.h" 13 #include "internal/quic_srtm.h" 14 #include "internal/quic_txp.h" 15 #include "internal/ssl_unwrap.h" 16 #include "quic_port_local.h" 17 #include "quic_channel_local.h" 18 #include "quic_engine_local.h" 19 #include "quic_local.h" 20 #include "../ssl_local.h" 21 #include <openssl/rand.h> 22 23 /* 24 * QUIC Port Structure 25 * =================== 26 */ 27 #define INIT_DCID_LEN 8 28 29 static int port_init(QUIC_PORT *port); 30 static void port_cleanup(QUIC_PORT *port); 31 static OSSL_TIME get_time(void *arg); 32 static void port_default_packet_handler(QUIC_URXE *e, void *arg, 33 const QUIC_CONN_ID *dcid); 34 static void port_rx_pre(QUIC_PORT *port); 35 36 /** 37 * @struct validation_token 38 * @brief Represents a validation token for secure connection handling. 39 * 40 * This struct is used to store information related to a validation token. 41 * 42 * @var validation_token::is_retry 43 * True iff this validation token is for a token sent in a RETRY packet. 44 * Otherwise, this token is from a NEW_TOKEN_packet. Iff this value is true, 45 * then ODCID and RSCID are set. 46 * 47 * @var validation_token::timestamp 48 * Time that the validation token was minted. 49 * 50 * @var validation_token::odcid 51 * An original connection ID (`QUIC_CONN_ID`) used to identify the QUIC 52 * connection. This ID helps associate the token with a specific connection. 53 * This will only be valid for validation tokens from RETRY packets. 54 * 55 * @var validation_token::rscid 56 * DCID that the client will use as the DCID of the subsequent initial packet 57 * i.e the "new" DCID. 58 * This will only be valid for validation tokens from RETRY packets. 59 * 60 * @var validation_token::remote_addr_len 61 * Length of the following character array. 62 * 63 * @var validation_token::remote_addr 64 * A character array holding the raw address of the client requesting the 65 * connection. 66 */ 67 typedef struct validation_token { 68 OSSL_TIME timestamp; 69 QUIC_CONN_ID odcid; 70 QUIC_CONN_ID rscid; 71 size_t remote_addr_len; 72 unsigned char *remote_addr; 73 unsigned char is_retry; 74 } QUIC_VALIDATION_TOKEN; 75 76 /* 77 * Maximum length of a marshalled validation token. 78 * 79 * - timestamp is 8 bytes 80 * - odcid and rscid are maximally 42 bytes in total 81 * - remote_addr_len is a size_t (8 bytes) 82 * - remote_addr is in the worst case 110 bytes (in the case of using a 83 * maximally sized AF_UNIX socket) 84 * - is_retry is a single byte 85 */ 86 #define MARSHALLED_TOKEN_MAX_LEN 169 87 88 /* 89 * Maximum length of an encrypted marshalled validation token. 90 * 91 * This will include the size of the marshalled validation token plus a 16 byte 92 * tag and a 12 byte IV, so in total 197 bytes. 93 */ 94 #define ENCRYPTED_TOKEN_MAX_LEN (MARSHALLED_TOKEN_MAX_LEN + 16 + 12) 95 96 DEFINE_LIST_OF_IMPL(ch, QUIC_CHANNEL); 97 DEFINE_LIST_OF_IMPL(incoming_ch, QUIC_CHANNEL); 98 DEFINE_LIST_OF_IMPL(port, QUIC_PORT); 99 100 QUIC_PORT *ossl_quic_port_new(const QUIC_PORT_ARGS *args) 101 { 102 QUIC_PORT *port; 103 104 if ((port = OPENSSL_zalloc(sizeof(QUIC_PORT))) == NULL) 105 return NULL; 106 107 port->engine = args->engine; 108 port->channel_ctx = args->channel_ctx; 109 port->is_multi_conn = args->is_multi_conn; 110 port->validate_addr = args->do_addr_validation; 111 port->get_conn_user_ssl = args->get_conn_user_ssl; 112 port->user_ssl_arg = args->user_ssl_arg; 113 114 if (!port_init(port)) { 115 OPENSSL_free(port); 116 return NULL; 117 } 118 119 return port; 120 } 121 122 void ossl_quic_port_free(QUIC_PORT *port) 123 { 124 if (port == NULL) 125 return; 126 127 port_cleanup(port); 128 OPENSSL_free(port); 129 } 130 131 static int port_init(QUIC_PORT *port) 132 { 133 size_t rx_short_dcid_len = (port->is_multi_conn ? INIT_DCID_LEN : 0); 134 int key_len; 135 EVP_CIPHER *cipher = NULL; 136 unsigned char *token_key = NULL; 137 int ret = 0; 138 139 if (port->engine == NULL || port->channel_ctx == NULL) 140 goto err; 141 142 if ((port->err_state = OSSL_ERR_STATE_new()) == NULL) 143 goto err; 144 145 if ((port->demux = ossl_quic_demux_new(/*BIO=*/NULL, 146 /*Short CID Len=*/rx_short_dcid_len, 147 get_time, port)) 148 == NULL) 149 goto err; 150 151 ossl_quic_demux_set_default_handler(port->demux, 152 port_default_packet_handler, 153 port); 154 155 if ((port->srtm = ossl_quic_srtm_new(port->engine->libctx, 156 port->engine->propq)) 157 == NULL) 158 goto err; 159 160 if ((port->lcidm = ossl_quic_lcidm_new(port->engine->libctx, 161 rx_short_dcid_len)) 162 == NULL) 163 goto err; 164 165 port->rx_short_dcid_len = (unsigned char)rx_short_dcid_len; 166 port->tx_init_dcid_len = INIT_DCID_LEN; 167 port->state = QUIC_PORT_STATE_RUNNING; 168 169 ossl_list_port_insert_tail(&port->engine->port_list, port); 170 port->on_engine_list = 1; 171 port->bio_changed = 1; 172 173 /* Generate random key for token encryption */ 174 if ((port->token_ctx = EVP_CIPHER_CTX_new()) == NULL 175 || (cipher = EVP_CIPHER_fetch(port->engine->libctx, 176 "AES-256-GCM", NULL)) 177 == NULL 178 || !EVP_EncryptInit_ex(port->token_ctx, cipher, NULL, NULL, NULL) 179 || (key_len = EVP_CIPHER_CTX_get_key_length(port->token_ctx)) <= 0 180 || (token_key = OPENSSL_malloc(key_len)) == NULL 181 || !RAND_bytes_ex(port->engine->libctx, token_key, key_len, 0) 182 || !EVP_EncryptInit_ex(port->token_ctx, NULL, NULL, token_key, NULL)) 183 goto err; 184 185 ret = 1; 186 err: 187 EVP_CIPHER_free(cipher); 188 OPENSSL_free(token_key); 189 if (!ret) 190 port_cleanup(port); 191 return ret; 192 } 193 194 static void port_cleanup(QUIC_PORT *port) 195 { 196 assert(ossl_list_ch_num(&port->channel_list) == 0); 197 198 ossl_quic_demux_free(port->demux); 199 port->demux = NULL; 200 201 ossl_quic_srtm_free(port->srtm); 202 port->srtm = NULL; 203 204 ossl_quic_lcidm_free(port->lcidm); 205 port->lcidm = NULL; 206 207 OSSL_ERR_STATE_free(port->err_state); 208 port->err_state = NULL; 209 210 if (port->on_engine_list) { 211 ossl_list_port_remove(&port->engine->port_list, port); 212 port->on_engine_list = 0; 213 } 214 215 EVP_CIPHER_CTX_free(port->token_ctx); 216 port->token_ctx = NULL; 217 } 218 219 static void port_transition_failed(QUIC_PORT *port) 220 { 221 if (port->state == QUIC_PORT_STATE_FAILED) 222 return; 223 224 port->state = QUIC_PORT_STATE_FAILED; 225 } 226 227 int ossl_quic_port_is_running(const QUIC_PORT *port) 228 { 229 return port->state == QUIC_PORT_STATE_RUNNING; 230 } 231 232 QUIC_ENGINE *ossl_quic_port_get0_engine(QUIC_PORT *port) 233 { 234 return port->engine; 235 } 236 237 QUIC_REACTOR *ossl_quic_port_get0_reactor(QUIC_PORT *port) 238 { 239 return ossl_quic_engine_get0_reactor(port->engine); 240 } 241 242 QUIC_DEMUX *ossl_quic_port_get0_demux(QUIC_PORT *port) 243 { 244 return port->demux; 245 } 246 247 CRYPTO_MUTEX *ossl_quic_port_get0_mutex(QUIC_PORT *port) 248 { 249 return ossl_quic_engine_get0_mutex(port->engine); 250 } 251 252 OSSL_TIME ossl_quic_port_get_time(QUIC_PORT *port) 253 { 254 return ossl_quic_engine_get_time(port->engine); 255 } 256 257 static OSSL_TIME get_time(void *port) 258 { 259 return ossl_quic_port_get_time((QUIC_PORT *)port); 260 } 261 262 int ossl_quic_port_get_rx_short_dcid_len(const QUIC_PORT *port) 263 { 264 return port->rx_short_dcid_len; 265 } 266 267 int ossl_quic_port_get_tx_init_dcid_len(const QUIC_PORT *port) 268 { 269 return port->tx_init_dcid_len; 270 } 271 272 size_t ossl_quic_port_get_num_incoming_channels(const QUIC_PORT *port) 273 { 274 return ossl_list_incoming_ch_num(&port->incoming_channel_list); 275 } 276 277 /* 278 * QUIC Port: Network BIO Configuration 279 * ==================================== 280 */ 281 282 /* Determines whether we can support a given poll descriptor. */ 283 static int validate_poll_descriptor(const BIO_POLL_DESCRIPTOR *d) 284 { 285 if (d->type == BIO_POLL_DESCRIPTOR_TYPE_SOCK_FD && d->value.fd < 0) { 286 ERR_raise(ERR_LIB_SSL, ERR_R_PASSED_INVALID_ARGUMENT); 287 return 0; 288 } 289 290 return 1; 291 } 292 293 BIO *ossl_quic_port_get_net_rbio(QUIC_PORT *port) 294 { 295 return port->net_rbio; 296 } 297 298 BIO *ossl_quic_port_get_net_wbio(QUIC_PORT *port) 299 { 300 return port->net_wbio; 301 } 302 303 static int port_update_poll_desc(QUIC_PORT *port, BIO *net_bio, int for_write) 304 { 305 BIO_POLL_DESCRIPTOR d = { 0 }; 306 307 if (net_bio == NULL 308 || (!for_write && !BIO_get_rpoll_descriptor(net_bio, &d)) 309 || (for_write && !BIO_get_wpoll_descriptor(net_bio, &d))) 310 /* Non-pollable BIO */ 311 d.type = BIO_POLL_DESCRIPTOR_TYPE_NONE; 312 313 if (!validate_poll_descriptor(&d)) 314 return 0; 315 316 /* 317 * TODO(QUIC MULTIPORT): We currently only support one port per 318 * engine/domain. This is necessitated because QUIC_REACTOR only supports a 319 * single pollable currently. In the future, once complete polling 320 * infrastructure has been implemented, this limitation can be removed. 321 * 322 * For now, just update the descriptor on the engine's reactor as we are 323 * guaranteed to be the only port under it. 324 */ 325 if (for_write) 326 ossl_quic_reactor_set_poll_w(&port->engine->rtor, &d); 327 else 328 ossl_quic_reactor_set_poll_r(&port->engine->rtor, &d); 329 330 return 1; 331 } 332 333 int ossl_quic_port_update_poll_descriptors(QUIC_PORT *port, int force) 334 { 335 int ok = 1; 336 337 if (!force && !port->bio_changed) 338 return 0; 339 340 if (!port_update_poll_desc(port, port->net_rbio, /*for_write=*/0)) 341 ok = 0; 342 343 if (!port_update_poll_desc(port, port->net_wbio, /*for_write=*/1)) 344 ok = 0; 345 346 port->bio_changed = 0; 347 return ok; 348 } 349 350 /* 351 * We need to determine our addressing mode. There are basically two ways we can 352 * use L4 addresses: 353 * 354 * - Addressed mode, in which our BIO_sendmmsg calls have destination 355 * addresses attached to them which we expect the underlying network BIO to 356 * handle; 357 * 358 * - Unaddressed mode, in which the BIO provided to us on the network side 359 * neither provides us with L4 addresses nor is capable of honouring ones we 360 * provide. We don't know where the QUIC traffic we send ends up exactly and 361 * trust the application to know what it is doing. 362 * 363 * Addressed mode is preferred because it enables support for connection 364 * migration, multipath, etc. in the future. Addressed mode is automatically 365 * enabled if we are using e.g. BIO_s_datagram, with or without BIO_s_connect. 366 * 367 * If we are passed a BIO_s_dgram_pair (or some custom BIO) we may have to use 368 * unaddressed mode unless that BIO supports capability flags indicating it can 369 * provide and honour L4 addresses. 370 * 371 * Our strategy for determining address mode is simple: we probe the underlying 372 * network BIOs for their capabilities. If the network BIOs support what we 373 * need, we use addressed mode. Otherwise, we use unaddressed mode. 374 * 375 * If addressed mode is chosen, we require an initial peer address to be set. If 376 * this is not set, we fail. If unaddressed mode is used, we do not require 377 * this, as such an address is superfluous, though it can be set if desired. 378 */ 379 static void port_update_addressing_mode(QUIC_PORT *port) 380 { 381 long rcaps = 0, wcaps = 0; 382 383 if (port->net_rbio != NULL) 384 rcaps = BIO_dgram_get_effective_caps(port->net_rbio); 385 386 if (port->net_wbio != NULL) 387 wcaps = BIO_dgram_get_effective_caps(port->net_wbio); 388 389 port->addressed_mode_r = ((rcaps & BIO_DGRAM_CAP_PROVIDES_SRC_ADDR) != 0); 390 port->addressed_mode_w = ((wcaps & BIO_DGRAM_CAP_HANDLES_DST_ADDR) != 0); 391 port->bio_changed = 1; 392 } 393 394 int ossl_quic_port_is_addressed_r(const QUIC_PORT *port) 395 { 396 return port->addressed_mode_r; 397 } 398 399 int ossl_quic_port_is_addressed_w(const QUIC_PORT *port) 400 { 401 return port->addressed_mode_w; 402 } 403 404 int ossl_quic_port_is_addressed(const QUIC_PORT *port) 405 { 406 return ossl_quic_port_is_addressed_r(port) && ossl_quic_port_is_addressed_w(port); 407 } 408 409 /* 410 * QUIC_PORT does not ref any BIO it is provided with, nor is any ref 411 * transferred to it. The caller (e.g., QUIC_CONNECTION) is responsible for 412 * ensuring the BIO lasts until the channel is freed or the BIO is switched out 413 * for another BIO by a subsequent successful call to this function. 414 */ 415 int ossl_quic_port_set_net_rbio(QUIC_PORT *port, BIO *net_rbio) 416 { 417 if (port->net_rbio == net_rbio) 418 return 1; 419 420 if (!port_update_poll_desc(port, net_rbio, /*for_write=*/0)) 421 return 0; 422 423 ossl_quic_demux_set_bio(port->demux, net_rbio); 424 port->net_rbio = net_rbio; 425 port_update_addressing_mode(port); 426 return 1; 427 } 428 429 int ossl_quic_port_set_net_wbio(QUIC_PORT *port, BIO *net_wbio) 430 { 431 QUIC_CHANNEL *ch; 432 433 if (port->net_wbio == net_wbio) 434 return 1; 435 436 if (!port_update_poll_desc(port, net_wbio, /*for_write=*/1)) 437 return 0; 438 439 OSSL_LIST_FOREACH(ch, ch, &port->channel_list) 440 ossl_qtx_set_bio(ch->qtx, net_wbio); 441 442 port->net_wbio = net_wbio; 443 port_update_addressing_mode(port); 444 return 1; 445 } 446 447 SSL_CTX *ossl_quic_port_get_channel_ctx(QUIC_PORT *port) 448 { 449 return port->channel_ctx; 450 } 451 452 /* 453 * QUIC Port: Channel Lifecycle 454 * ============================ 455 */ 456 457 static SSL *port_new_handshake_layer(QUIC_PORT *port, QUIC_CHANNEL *ch) 458 { 459 SSL *tls = NULL; 460 SSL_CONNECTION *tls_conn = NULL; 461 SSL *user_ssl = NULL; 462 QUIC_CONNECTION *qc = NULL; 463 QUIC_LISTENER *ql = NULL; 464 465 /* 466 * It only makes sense to call this function if we know how to associate 467 * the handshake layer we are about to create with some user_ssl object. 468 */ 469 if (!ossl_assert(port->get_conn_user_ssl != NULL)) 470 return NULL; 471 user_ssl = port->get_conn_user_ssl(ch, port->user_ssl_arg); 472 if (user_ssl == NULL) 473 return NULL; 474 qc = (QUIC_CONNECTION *)user_ssl; 475 ql = (QUIC_LISTENER *)port->user_ssl_arg; 476 477 /* 478 * We expect the user_ssl to be newly created so it must not have an 479 * existing qc->tls 480 */ 481 if (!ossl_assert(qc->tls == NULL)) { 482 SSL_free(user_ssl); 483 return NULL; 484 } 485 486 tls = ossl_ssl_connection_new_int(port->channel_ctx, user_ssl, TLS_method()); 487 qc->tls = tls; 488 if (tls == NULL || (tls_conn = SSL_CONNECTION_FROM_SSL(tls)) == NULL) { 489 SSL_free(user_ssl); 490 return NULL; 491 } 492 493 if (ql != NULL && ql->obj.ssl.ctx->new_pending_conn_cb != NULL) 494 if (!ql->obj.ssl.ctx->new_pending_conn_cb(ql->obj.ssl.ctx, user_ssl, 495 ql->obj.ssl.ctx->new_pending_conn_arg)) { 496 SSL_free(user_ssl); 497 return NULL; 498 } 499 500 /* Override the user_ssl of the inner connection. */ 501 tls_conn->s3.flags |= TLS1_FLAGS_QUIC | TLS1_FLAGS_QUIC_INTERNAL; 502 503 /* Restrict options derived from the SSL_CTX. */ 504 tls_conn->options &= OSSL_QUIC_PERMITTED_OPTIONS_CONN; 505 tls_conn->pha_enabled = 0; 506 return tls; 507 } 508 509 static QUIC_CHANNEL *port_make_channel(QUIC_PORT *port, SSL *tls, OSSL_QRX *qrx, 510 int is_server, int is_tserver) 511 { 512 QUIC_CHANNEL_ARGS args = { 0 }; 513 QUIC_CHANNEL *ch; 514 515 args.port = port; 516 args.is_server = is_server; 517 args.lcidm = port->lcidm; 518 args.srtm = port->srtm; 519 args.qrx = qrx; 520 args.is_tserver_ch = is_tserver; 521 522 /* 523 * Creating a a new channel is made a bit tricky here as there is a 524 * bit of a circular dependency. Initializing a channel requires that 525 * the ch->tls and optionally the qlog_title be configured prior to 526 * initialization, but we need the channel at least partially configured 527 * to create the new handshake layer, so we have to do this in a few steps. 528 */ 529 530 /* 531 * start by allocation and provisioning as much of the channel as we can 532 */ 533 ch = ossl_quic_channel_alloc(&args); 534 if (ch == NULL) 535 return NULL; 536 537 /* 538 * Fixup the channel tls connection here before we init the channel 539 */ 540 ch->tls = (tls != NULL) ? tls : port_new_handshake_layer(port, ch); 541 542 if (ch->tls == NULL) { 543 OPENSSL_free(ch); 544 return NULL; 545 } 546 547 #ifndef OPENSSL_NO_QLOG 548 /* 549 * If we're using qlog, make sure the tls get further configured properly 550 */ 551 ch->use_qlog = 1; 552 if (ch->tls->ctx->qlog_title != NULL) { 553 if ((ch->qlog_title = OPENSSL_strdup(ch->tls->ctx->qlog_title)) == NULL) { 554 OPENSSL_free(ch); 555 return NULL; 556 } 557 } 558 #endif 559 560 /* 561 * And finally init the channel struct 562 */ 563 if (!ossl_quic_channel_init(ch)) { 564 OPENSSL_free(ch); 565 return NULL; 566 } 567 568 ossl_qtx_set_bio(ch->qtx, port->net_wbio); 569 return ch; 570 } 571 572 QUIC_CHANNEL *ossl_quic_port_create_outgoing(QUIC_PORT *port, SSL *tls) 573 { 574 return port_make_channel(port, tls, NULL, /* is_server= */ 0, 575 /* is_tserver= */ 0); 576 } 577 578 QUIC_CHANNEL *ossl_quic_port_create_incoming(QUIC_PORT *port, SSL *tls) 579 { 580 QUIC_CHANNEL *ch; 581 582 assert(port->tserver_ch == NULL); 583 584 /* 585 * pass -1 for qrx to indicate port will create qrx 586 * later in port_default_packet_handler() when calling port_bind_channel(). 587 */ 588 ch = port_make_channel(port, tls, NULL, /* is_server= */ 1, 589 /* is_tserver_ch */ 1); 590 port->tserver_ch = ch; 591 port->allow_incoming = 1; 592 return ch; 593 } 594 595 QUIC_CHANNEL *ossl_quic_port_pop_incoming(QUIC_PORT *port) 596 { 597 QUIC_CHANNEL *ch; 598 599 ch = ossl_list_incoming_ch_head(&port->incoming_channel_list); 600 if (ch == NULL) 601 return NULL; 602 603 ossl_list_incoming_ch_remove(&port->incoming_channel_list, ch); 604 return ch; 605 } 606 607 int ossl_quic_port_have_incoming(QUIC_PORT *port) 608 { 609 return ossl_list_incoming_ch_head(&port->incoming_channel_list) != NULL; 610 } 611 612 void ossl_quic_port_drop_incoming(QUIC_PORT *port) 613 { 614 QUIC_CHANNEL *ch; 615 SSL *tls; 616 SSL *user_ssl; 617 SSL_CONNECTION *sc; 618 619 for (;;) { 620 ch = ossl_quic_port_pop_incoming(port); 621 if (ch == NULL) 622 break; 623 624 tls = ossl_quic_channel_get0_tls(ch); 625 /* 626 * The user ssl may or may not have been created via the 627 * get_conn_user_ssl callback in the QUIC stack. The 628 * differentiation being if the user_ssl pointer and tls pointer 629 * are different. If they are, then the user_ssl needs freeing here 630 * which sends us through ossl_quic_free, which then drops the actual 631 * ch->tls ref and frees the channel 632 */ 633 sc = SSL_CONNECTION_FROM_SSL(tls); 634 if (sc == NULL) 635 break; 636 637 user_ssl = SSL_CONNECTION_GET_USER_SSL(sc); 638 if (user_ssl == tls) { 639 ossl_quic_channel_free(ch); 640 SSL_free(tls); 641 } else { 642 SSL_free(user_ssl); 643 } 644 } 645 } 646 647 void ossl_quic_port_set_allow_incoming(QUIC_PORT *port, int allow_incoming) 648 { 649 port->allow_incoming = allow_incoming; 650 } 651 652 /* 653 * QUIC Port: Ticker-Mutator 654 * ========================= 655 */ 656 657 /* 658 * Tick function for this port. This does everything related to network I/O for 659 * this port's network BIOs, and services child channels. 660 */ 661 void ossl_quic_port_subtick(QUIC_PORT *port, QUIC_TICK_RESULT *res, 662 uint32_t flags) 663 { 664 QUIC_CHANNEL *ch; 665 666 res->net_read_desired = ossl_quic_port_is_running(port); 667 res->net_write_desired = 0; 668 res->notify_other_threads = 0; 669 res->tick_deadline = ossl_time_infinite(); 670 671 if (!port->engine->inhibit_tick) { 672 /* Handle any incoming data from network. */ 673 if (ossl_quic_port_is_running(port)) 674 port_rx_pre(port); 675 676 /* Iterate through all channels and service them. */ 677 OSSL_LIST_FOREACH(ch, ch, &port->channel_list) 678 { 679 QUIC_TICK_RESULT subr = { 0 }; 680 681 ossl_quic_channel_subtick(ch, &subr, flags); 682 ossl_quic_tick_result_merge_into(res, &subr); 683 } 684 } 685 } 686 687 /* Process incoming datagrams, if any. */ 688 static void port_rx_pre(QUIC_PORT *port) 689 { 690 int ret; 691 692 /* 693 * Originally, this check (don't RX before we have sent anything if we are 694 * not a server, because there can't be anything) was just intended as a 695 * minor optimisation. However, it is actually required on Windows, and 696 * removing this check will cause Windows to break. 697 * 698 * The reason is that under Win32, recvfrom() does not work on a UDP socket 699 * which has not had bind() called (???). However, calling sendto() will 700 * automatically bind an unbound UDP socket. Therefore, if we call a Winsock 701 * recv-type function before calling a Winsock send-type function, that call 702 * will fail with WSAEINVAL, which we will regard as a permanent network 703 * error. 704 * 705 * Therefore, this check is essential as we do not require our API users to 706 * bind a socket first when using the API in client mode. 707 */ 708 if (!port->allow_incoming && !port->have_sent_any_pkt) 709 return; 710 711 /* 712 * Get DEMUX to BIO_recvmmsg from the network and queue incoming datagrams 713 * to the appropriate QRX instances. 714 */ 715 ret = ossl_quic_demux_pump(port->demux); 716 if (ret == QUIC_DEMUX_PUMP_RES_PERMANENT_FAIL) 717 /* 718 * We don't care about transient failure, but permanent failure means we 719 * should tear down the port. All connections skip straight to the 720 * Terminated state as there is no point trying to send CONNECTION_CLOSE 721 * frames if the network BIO is not operating correctly. 722 */ 723 ossl_quic_port_raise_net_error(port, NULL); 724 } 725 726 /* 727 * Handles an incoming connection request and potentially decides to make a 728 * connection from it. If a new connection is made, the new channel is written 729 * to *new_ch. 730 */ 731 static void port_bind_channel(QUIC_PORT *port, const BIO_ADDR *peer, 732 const QUIC_CONN_ID *scid, const QUIC_CONN_ID *dcid, 733 const QUIC_CONN_ID *odcid, OSSL_QRX *qrx, 734 QUIC_CHANNEL **new_ch) 735 { 736 QUIC_CHANNEL *ch; 737 738 /* 739 * If we're running with a simulated tserver, it will already have 740 * a dummy channel created, use that instead 741 */ 742 if (port->tserver_ch != NULL) { 743 ch = port->tserver_ch; 744 port->tserver_ch = NULL; 745 ossl_quic_channel_bind_qrx(ch, qrx); 746 ossl_qrx_set_msg_callback(ch->qrx, ch->msg_callback, 747 ch->msg_callback_ssl); 748 ossl_qrx_set_msg_callback_arg(ch->qrx, ch->msg_callback_arg); 749 } else { 750 ch = port_make_channel(port, NULL, qrx, /* is_server= */ 1, 751 /* is_tserver */ 0); 752 } 753 754 if (ch == NULL) 755 return; 756 757 /* 758 * If we didn't provide a qrx here that means we need to set our initial 759 * secret here, since we just created a qrx 760 * Normally its not needed, as the initial secret gets added when we send 761 * our first server hello, but if we get a huge client hello, crossing 762 * multiple datagrams, we don't have a chance to do that, and datagrams 763 * after the first won't get decoded properly, for lack of secrets 764 */ 765 if (qrx == NULL) 766 if (!ossl_quic_provide_initial_secret(ch->port->engine->libctx, 767 ch->port->engine->propq, 768 dcid, /* is_server */ 1, 769 ch->qrx, NULL)) 770 return; 771 772 if (odcid->id_len != 0) { 773 /* 774 * If we have an odcid, then we went through server address validation 775 * and as such, this channel need not conform to the 3x validation cap 776 * See RFC 9000 s. 8.1 777 */ 778 ossl_quic_tx_packetiser_set_validated(ch->txp); 779 if (!ossl_quic_bind_channel(ch, peer, scid, dcid, odcid)) { 780 ossl_quic_channel_free(ch); 781 return; 782 } 783 } else { 784 /* 785 * No odcid means we didn't do server validation, so we need to 786 * generate a cid via ossl_quic_channel_on_new_conn 787 */ 788 if (!ossl_quic_channel_on_new_conn(ch, peer, scid, dcid)) { 789 ossl_quic_channel_free(ch); 790 return; 791 } 792 } 793 794 ossl_list_incoming_ch_insert_tail(&port->incoming_channel_list, ch); 795 *new_ch = ch; 796 } 797 798 static int port_try_handle_stateless_reset(QUIC_PORT *port, const QUIC_URXE *e) 799 { 800 size_t i; 801 const unsigned char *data = ossl_quic_urxe_data(e); 802 void *opaque = NULL; 803 804 /* 805 * Perform some fast and cheap checks for a packet not being a stateless 806 * reset token. RFC 9000 s. 10.3 specifies this layout for stateless 807 * reset packets: 808 * 809 * Stateless Reset { 810 * Fixed Bits (2) = 1, 811 * Unpredictable Bits (38..), 812 * Stateless Reset Token (128), 813 * } 814 * 815 * It also specifies: 816 * However, endpoints MUST treat any packet ending in a valid 817 * stateless reset token as a Stateless Reset, as other QUIC 818 * versions might allow the use of a long header. 819 * 820 * We can rapidly check for the minimum length and that the first pair 821 * of bits in the first byte are 01 or 11. 822 * 823 * The function returns 1 if it is a stateless reset packet, 0 if it isn't 824 * and -1 if an error was encountered. 825 */ 826 if (e->data_len < QUIC_STATELESS_RESET_TOKEN_LEN + 5 827 || (0100 & *data) != 0100) 828 return 0; 829 830 for (i = 0;; ++i) { 831 if (!ossl_quic_srtm_lookup(port->srtm, 832 (QUIC_STATELESS_RESET_TOKEN *)(data + e->data_len 833 - sizeof(QUIC_STATELESS_RESET_TOKEN)), 834 i, &opaque, NULL)) 835 break; 836 837 assert(opaque != NULL); 838 ossl_quic_channel_on_stateless_reset((QUIC_CHANNEL *)opaque); 839 } 840 841 return i > 0; 842 } 843 844 static void cleanup_validation_token(QUIC_VALIDATION_TOKEN *token) 845 { 846 OPENSSL_free(token->remote_addr); 847 } 848 849 /** 850 * @brief Generates a validation token for a RETRY/NEW_TOKEN packet. 851 * 852 * 853 * @param peer Address of the client peer receiving the packet. 854 * @param odcid DCID of the connection attempt. 855 * @param rscid Retry source connection ID of the connection attempt. 856 * @param token Address of token to fill data. 857 * 858 * @return 1 if validation token is filled successfully, 0 otherwise. 859 */ 860 static int generate_token(BIO_ADDR *peer, QUIC_CONN_ID odcid, 861 QUIC_CONN_ID rscid, QUIC_VALIDATION_TOKEN *token, 862 int is_retry) 863 { 864 token->is_retry = is_retry; 865 token->timestamp = ossl_time_now(); 866 token->remote_addr = NULL; 867 token->odcid = odcid; 868 token->rscid = rscid; 869 870 if (!BIO_ADDR_rawaddress(peer, NULL, &token->remote_addr_len) 871 || token->remote_addr_len == 0 872 || (token->remote_addr = OPENSSL_malloc(token->remote_addr_len)) == NULL 873 || !BIO_ADDR_rawaddress(peer, token->remote_addr, 874 &token->remote_addr_len)) { 875 cleanup_validation_token(token); 876 return 0; 877 } 878 879 return 1; 880 } 881 882 /** 883 * @brief Marshals a validation token into a new buffer. 884 * 885 * |buffer| should already be allocated and at least MARSHALLED_TOKEN_MAX_LEN 886 * bytes long. Stores the length of data stored in |buffer| in |buffer_len|. 887 * 888 * @param token Validation token. 889 * @param buffer Address to store the marshalled token. 890 * @param buffer_len Size of data stored in |buffer|. 891 */ 892 static int marshal_validation_token(QUIC_VALIDATION_TOKEN *token, 893 unsigned char *buffer, size_t *buffer_len) 894 { 895 WPACKET wpkt = { 0 }; 896 BUF_MEM *buf_mem = BUF_MEM_new(); 897 898 if (buffer == NULL || buf_mem == NULL 899 || (token->is_retry != 0 && token->is_retry != 1)) { 900 BUF_MEM_free(buf_mem); 901 return 0; 902 } 903 904 if (!WPACKET_init(&wpkt, buf_mem) 905 || !WPACKET_memset(&wpkt, token->is_retry, 1) 906 || !WPACKET_memcpy(&wpkt, &token->timestamp, 907 sizeof(token->timestamp)) 908 || (token->is_retry 909 && (!WPACKET_sub_memcpy_u8(&wpkt, &token->odcid.id, 910 token->odcid.id_len) 911 || !WPACKET_sub_memcpy_u8(&wpkt, &token->rscid.id, 912 token->rscid.id_len))) 913 || !WPACKET_sub_memcpy_u8(&wpkt, token->remote_addr, token->remote_addr_len) 914 || !WPACKET_get_total_written(&wpkt, buffer_len) 915 || *buffer_len > MARSHALLED_TOKEN_MAX_LEN 916 || !WPACKET_finish(&wpkt)) { 917 WPACKET_cleanup(&wpkt); 918 BUF_MEM_free(buf_mem); 919 return 0; 920 } 921 922 memcpy(buffer, buf_mem->data, *buffer_len); 923 BUF_MEM_free(buf_mem); 924 return 1; 925 } 926 927 /** 928 * @brief Encrypts a validation token using AES-256-GCM 929 * 930 * @param port The QUIC port containing the encryption key 931 * @param plaintext The data to encrypt 932 * @param pt_len Length of the plaintext 933 * @param ciphertext Buffer to receive encrypted data. If NULL, ct_len will be 934 * set to the required buffer size and function returns 935 * immediately. 936 * @param ct_len Pointer to size_t that will receive the ciphertext length. 937 * This also includes bytes for QUIC_RETRY_INTEGRITY_TAG_LEN. 938 * 939 * @return 1 on success, 0 on failure 940 * 941 * The ciphertext format is: 942 * [EVP_GCM_IV_LEN bytes IV][encrypted data][EVP_GCM_TAG_LEN bytes tag] 943 */ 944 static int encrypt_validation_token(const QUIC_PORT *port, 945 const unsigned char *plaintext, 946 size_t pt_len, 947 unsigned char *ciphertext, 948 size_t *ct_len) 949 { 950 int iv_len, len, ret = 0; 951 size_t tag_len; 952 unsigned char *iv = ciphertext, *data, *tag; 953 954 if ((tag_len = EVP_CIPHER_CTX_get_tag_length(port->token_ctx)) == 0 955 || (iv_len = EVP_CIPHER_CTX_get_iv_length(port->token_ctx)) <= 0) 956 goto err; 957 958 *ct_len = iv_len + pt_len + tag_len + QUIC_RETRY_INTEGRITY_TAG_LEN; 959 if (ciphertext == NULL) { 960 ret = 1; 961 goto err; 962 } 963 964 data = ciphertext + iv_len; 965 tag = data + pt_len; 966 967 if (!RAND_bytes_ex(port->engine->libctx, ciphertext, iv_len, 0) 968 || !EVP_EncryptInit_ex(port->token_ctx, NULL, NULL, NULL, iv) 969 || !EVP_EncryptUpdate(port->token_ctx, data, &len, plaintext, pt_len) 970 || !EVP_EncryptFinal_ex(port->token_ctx, data + pt_len, &len) 971 || !EVP_CIPHER_CTX_ctrl(port->token_ctx, EVP_CTRL_GCM_GET_TAG, tag_len, tag)) 972 goto err; 973 974 ret = 1; 975 err: 976 return ret; 977 } 978 979 /** 980 * @brief Decrypts a validation token using AES-256-GCM 981 * 982 * @param port The QUIC port containing the decryption key 983 * @param ciphertext The encrypted data (including IV and tag) 984 * @param ct_len Length of the ciphertext 985 * @param plaintext Buffer to receive decrypted data. If NULL, pt_len will be 986 * set to the required buffer size. 987 * @param pt_len Pointer to size_t that will receive the plaintext length 988 * 989 * @return 1 on success, 0 on failure 990 * 991 * Expected ciphertext format: 992 * [EVP_GCM_IV_LEN bytes IV][encrypted data][EVP_GCM_TAG_LEN bytes tag] 993 */ 994 static int decrypt_validation_token(const QUIC_PORT *port, 995 const unsigned char *ciphertext, 996 size_t ct_len, 997 unsigned char *plaintext, 998 size_t *pt_len) 999 { 1000 int iv_len, len = 0, ret = 0; 1001 size_t tag_len; 1002 const unsigned char *iv = ciphertext, *data, *tag; 1003 1004 if ((tag_len = EVP_CIPHER_CTX_get_tag_length(port->token_ctx)) == 0 1005 || (iv_len = EVP_CIPHER_CTX_get_iv_length(port->token_ctx)) <= 0) 1006 goto err; 1007 1008 /* Prevent decryption of a buffer that is not within reasonable bounds */ 1009 if (ct_len < (iv_len + tag_len) || ct_len > ENCRYPTED_TOKEN_MAX_LEN) 1010 goto err; 1011 1012 *pt_len = ct_len - iv_len - tag_len; 1013 if (plaintext == NULL) { 1014 ret = 1; 1015 goto err; 1016 } 1017 1018 data = ciphertext + iv_len; 1019 tag = ciphertext + ct_len - tag_len; 1020 1021 if (!EVP_DecryptInit_ex(port->token_ctx, NULL, NULL, NULL, iv) 1022 || !EVP_DecryptUpdate(port->token_ctx, plaintext, &len, data, 1023 ct_len - iv_len - tag_len) 1024 || !EVP_CIPHER_CTX_ctrl(port->token_ctx, EVP_CTRL_GCM_SET_TAG, tag_len, 1025 (void *)tag) 1026 || !EVP_DecryptFinal_ex(port->token_ctx, plaintext + len, &len)) 1027 goto err; 1028 1029 ret = 1; 1030 1031 err: 1032 return ret; 1033 } 1034 1035 /** 1036 * @brief Parses contents of a buffer into a validation token. 1037 * 1038 * VALIDATION_TOKEN should already be initialized. Does some basic sanity checks. 1039 * 1040 * @param token Validation token to fill data in. 1041 * @param buf Buffer of previously marshaled validation token. 1042 * @param buf_len Length of |buf|. 1043 */ 1044 static int parse_validation_token(QUIC_VALIDATION_TOKEN *token, 1045 const unsigned char *buf, size_t buf_len) 1046 { 1047 PACKET pkt, subpkt; 1048 1049 if (buf == NULL || token == NULL) 1050 return 0; 1051 1052 token->remote_addr = NULL; 1053 1054 if (!PACKET_buf_init(&pkt, buf, buf_len) 1055 || !PACKET_copy_bytes(&pkt, &token->is_retry, sizeof(token->is_retry)) 1056 || !(token->is_retry == 0 || token->is_retry == 1) 1057 || !PACKET_copy_bytes(&pkt, (unsigned char *)&token->timestamp, 1058 sizeof(token->timestamp)) 1059 || (token->is_retry 1060 && (!PACKET_get_length_prefixed_1(&pkt, &subpkt) 1061 || (token->odcid.id_len = (unsigned char)PACKET_remaining(&subpkt)) 1062 > QUIC_MAX_CONN_ID_LEN 1063 || !PACKET_copy_bytes(&subpkt, 1064 (unsigned char *)&token->odcid.id, 1065 token->odcid.id_len) 1066 || !PACKET_get_length_prefixed_1(&pkt, &subpkt) 1067 || (token->rscid.id_len = (unsigned char)PACKET_remaining(&subpkt)) 1068 > QUIC_MAX_CONN_ID_LEN 1069 || !PACKET_copy_bytes(&subpkt, (unsigned char *)&token->rscid.id, 1070 token->rscid.id_len))) 1071 || !PACKET_get_length_prefixed_1(&pkt, &subpkt) 1072 || (token->remote_addr_len = PACKET_remaining(&subpkt)) == 0 1073 || (token->remote_addr = OPENSSL_malloc(token->remote_addr_len)) == NULL 1074 || !PACKET_copy_bytes(&subpkt, token->remote_addr, token->remote_addr_len) 1075 || PACKET_remaining(&pkt) != 0) { 1076 cleanup_validation_token(token); 1077 return 0; 1078 } 1079 1080 return 1; 1081 } 1082 1083 /** 1084 * @brief Sends a QUIC Retry packet to a client. 1085 * 1086 * This function constructs and sends a Retry packet to the specified client 1087 * using the provided connection header information. The Retry packet 1088 * includes a generated validation token and a new connection ID, following 1089 * the QUIC protocol specifications for connection establishment. 1090 * 1091 * @param port Pointer to the QUIC port from which to send the packet. 1092 * @param peer Address of the client peer receiving the packet. 1093 * @param client_hdr Header of the client's initial packet, containing 1094 * connection IDs and other relevant information. 1095 * 1096 * This function performs the following steps: 1097 * - Generates a validation token for the client. 1098 * - Sets the destination and source connection IDs. 1099 * - Calculates the integrity tag and sets the token length. 1100 * - Encodes and sends the packet via the BIO network interface. 1101 * 1102 * Error handling is included for failures in CID generation, encoding, and 1103 * network transmiss 1104 */ 1105 static void port_send_retry(QUIC_PORT *port, 1106 BIO_ADDR *peer, 1107 QUIC_PKT_HDR *client_hdr) 1108 { 1109 BIO_MSG msg[1]; 1110 /* 1111 * Buffer is used for both marshalling the token as well as for the RETRY 1112 * packet. The size of buffer should not be less than 1113 * MARSHALLED_TOKEN_MAX_LEN. 1114 */ 1115 unsigned char buffer[512]; 1116 unsigned char ct_buf[ENCRYPTED_TOKEN_MAX_LEN]; 1117 WPACKET wpkt; 1118 size_t written, token_buf_len, ct_len; 1119 QUIC_PKT_HDR hdr = { 0 }; 1120 QUIC_VALIDATION_TOKEN token = { 0 }; 1121 int ok; 1122 1123 if (!ossl_assert(sizeof(buffer) >= MARSHALLED_TOKEN_MAX_LEN)) 1124 return; 1125 /* 1126 * 17.2.5.1 Sending a Retry packet 1127 * dst ConnId is src ConnId we got from client 1128 * src ConnId comes from local conn ID manager 1129 */ 1130 memset(&hdr, 0, sizeof(QUIC_PKT_HDR)); 1131 hdr.dst_conn_id = client_hdr->src_conn_id; 1132 /* 1133 * this is the random connection ID, we expect client is 1134 * going to send the ID with next INITIAL packet which 1135 * will also come with token we generate here. 1136 */ 1137 ok = ossl_quic_lcidm_get_unused_cid(port->lcidm, &hdr.src_conn_id); 1138 if (ok == 0) 1139 goto err; 1140 1141 memset(&token, 0, sizeof(QUIC_VALIDATION_TOKEN)); 1142 1143 /* Generate retry validation token */ 1144 if (!generate_token(peer, client_hdr->dst_conn_id, 1145 hdr.src_conn_id, &token, 1) 1146 || !marshal_validation_token(&token, buffer, &token_buf_len) 1147 || !encrypt_validation_token(port, buffer, token_buf_len, NULL, 1148 &ct_len) 1149 || ct_len > ENCRYPTED_TOKEN_MAX_LEN 1150 || !encrypt_validation_token(port, buffer, token_buf_len, ct_buf, 1151 &ct_len) 1152 || !ossl_assert(ct_len >= QUIC_RETRY_INTEGRITY_TAG_LEN)) 1153 goto err; 1154 1155 hdr.dst_conn_id = client_hdr->src_conn_id; 1156 hdr.type = QUIC_PKT_TYPE_RETRY; 1157 hdr.fixed = 1; 1158 hdr.version = 1; 1159 hdr.len = ct_len; 1160 hdr.data = ct_buf; 1161 ok = ossl_quic_calculate_retry_integrity_tag(port->engine->libctx, 1162 port->engine->propq, &hdr, 1163 &client_hdr->dst_conn_id, 1164 ct_buf + ct_len 1165 - QUIC_RETRY_INTEGRITY_TAG_LEN); 1166 if (ok == 0) 1167 goto err; 1168 1169 hdr.token = hdr.data; 1170 hdr.token_len = hdr.len; 1171 1172 msg[0].data = buffer; 1173 msg[0].peer = peer; 1174 msg[0].local = NULL; 1175 msg[0].flags = 0; 1176 1177 ok = WPACKET_init_static_len(&wpkt, buffer, sizeof(buffer), 0); 1178 if (ok == 0) 1179 goto err; 1180 1181 ok = ossl_quic_wire_encode_pkt_hdr(&wpkt, client_hdr->dst_conn_id.id_len, 1182 &hdr, NULL); 1183 if (ok == 0) 1184 goto err; 1185 1186 ok = WPACKET_get_total_written(&wpkt, &msg[0].data_len); 1187 if (ok == 0) 1188 goto err; 1189 1190 ok = WPACKET_finish(&wpkt); 1191 if (ok == 0) 1192 goto err; 1193 1194 /* 1195 * TODO(QUIC FUTURE) need to retry this in the event it return EAGAIN 1196 * on a non-blocking BIO 1197 */ 1198 if (!BIO_sendmmsg(port->net_wbio, msg, sizeof(BIO_MSG), 1, 0, &written)) 1199 ERR_raise_data(ERR_LIB_SSL, SSL_R_QUIC_NETWORK_ERROR, 1200 "port retry send failed due to network BIO I/O error"); 1201 1202 err: 1203 cleanup_validation_token(&token); 1204 } 1205 1206 /** 1207 * @brief Sends a QUIC Version Negotiation packet to the specified peer. 1208 * 1209 * This function constructs and sends a Version Negotiation packet using 1210 * the connection IDs from the client's initial packet header. The 1211 * Version Negotiation packet indicates support for QUIC version 1. 1212 * 1213 * @param port Pointer to the QUIC_PORT structure representing the port 1214 * context used for network communication. 1215 * @param peer Pointer to the BIO_ADDR structure specifying the address 1216 * of the peer to which the Version Negotiation packet 1217 * will be sent. 1218 * @param client_hdr Pointer to the QUIC_PKT_HDR structure containing the 1219 * client's packet header used to extract connection IDs. 1220 * 1221 * @note The function will raise an error if sending the message fails. 1222 */ 1223 static void port_send_version_negotiation(QUIC_PORT *port, BIO_ADDR *peer, 1224 QUIC_PKT_HDR *client_hdr) 1225 { 1226 BIO_MSG msg[1]; 1227 unsigned char buffer[1024]; 1228 QUIC_PKT_HDR hdr; 1229 WPACKET wpkt; 1230 uint32_t supported_versions[1]; 1231 size_t written; 1232 size_t i; 1233 1234 memset(&hdr, 0, sizeof(QUIC_PKT_HDR)); 1235 /* 1236 * Reverse the source and dst conn ids 1237 */ 1238 hdr.dst_conn_id = client_hdr->src_conn_id; 1239 hdr.src_conn_id = client_hdr->dst_conn_id; 1240 1241 /* 1242 * This is our list of supported protocol versions 1243 * Currently only QUIC_VERSION_1 1244 */ 1245 supported_versions[0] = QUIC_VERSION_1; 1246 1247 /* 1248 * Fill out the header fields 1249 * Note: Version negotiation packets, must, unlike 1250 * other packet types have a version of 0 1251 */ 1252 hdr.type = QUIC_PKT_TYPE_VERSION_NEG; 1253 hdr.version = 0; 1254 hdr.token = 0; 1255 hdr.token_len = 0; 1256 hdr.len = sizeof(supported_versions); 1257 hdr.data = (unsigned char *)supported_versions; 1258 1259 msg[0].data = buffer; 1260 msg[0].peer = peer; 1261 msg[0].local = NULL; 1262 msg[0].flags = 0; 1263 1264 if (!WPACKET_init_static_len(&wpkt, buffer, sizeof(buffer), 0)) 1265 return; 1266 1267 if (!ossl_quic_wire_encode_pkt_hdr(&wpkt, client_hdr->dst_conn_id.id_len, 1268 &hdr, NULL)) 1269 return; 1270 1271 /* 1272 * Add the array of supported versions to the end of the packet 1273 */ 1274 for (i = 0; i < OSSL_NELEM(supported_versions); i++) { 1275 if (!WPACKET_put_bytes_u32(&wpkt, supported_versions[i])) 1276 return; 1277 } 1278 1279 if (!WPACKET_get_total_written(&wpkt, &msg[0].data_len)) 1280 return; 1281 1282 if (!WPACKET_finish(&wpkt)) 1283 return; 1284 1285 /* 1286 * Send it back to the client attempting to connect 1287 * TODO(QUIC FUTURE): Need to handle the EAGAIN case here, if the 1288 * BIO_sendmmsg call falls in a retryable manner 1289 */ 1290 if (!BIO_sendmmsg(port->net_wbio, msg, sizeof(BIO_MSG), 1, 0, &written)) 1291 ERR_raise_data(ERR_LIB_SSL, SSL_R_QUIC_NETWORK_ERROR, 1292 "port version negotiation send failed"); 1293 } 1294 1295 /** 1296 * @brief definitions of token lifetimes 1297 * 1298 * RETRY tokens are only valid for 10 seconds 1299 * NEW_TOKEN tokens have a lifetime of 3600 sec (1 hour) 1300 */ 1301 1302 #define RETRY_LIFETIME 10 1303 #define NEW_TOKEN_LIFETIME 3600 1304 /** 1305 * @brief Validates a received token in a QUIC packet header. 1306 * 1307 * This function checks the validity of a token contained in the provided 1308 * QUIC packet header (`QUIC_PKT_HDR *hdr`). The validation process involves 1309 * verifying that the token matches an expected format and value. If the 1310 * token is from a RETRY packet, the function extracts the original connection 1311 * ID (ODCID)/original source connection ID (SCID) and stores it in the provided 1312 * parameters. If the token is from a NEW_TOKEN packet, the values will be 1313 * derived instead. 1314 * 1315 * @param hdr Pointer to the QUIC packet header containing the token. 1316 * @param port Pointer to the QUIC port from which to send the packet. 1317 * @param peer Address of the client peer receiving the packet. 1318 * @param odcid Pointer to the connection ID structure to store the ODCID if the 1319 * token is valid. 1320 * @param scid Pointer to the connection ID structure to store the SCID if the 1321 * token is valid. 1322 * 1323 * @return 1 if the token is valid and ODCID/SCID are successfully set. 1324 * 0 otherwise. 1325 * 1326 * The function performs the following checks: 1327 * - Token length meets the required minimum. 1328 * - Buffer matches expected format. 1329 * - Peer address matches previous connection address. 1330 * - Token has not expired. Currently set to 10 seconds for tokens from RETRY 1331 * packets and 60 minutes for tokens from NEW_TOKEN packets. This may be 1332 * configurable in the future. 1333 */ 1334 static int port_validate_token(QUIC_PKT_HDR *hdr, QUIC_PORT *port, 1335 BIO_ADDR *peer, QUIC_CONN_ID *odcid, 1336 QUIC_CONN_ID *scid, uint8_t *gen_new_token) 1337 { 1338 int ret = 0; 1339 QUIC_VALIDATION_TOKEN token = { 0 }; 1340 uint64_t time_diff; 1341 size_t remote_addr_len, dec_token_len; 1342 unsigned char *remote_addr = NULL, dec_token[MARSHALLED_TOKEN_MAX_LEN]; 1343 OSSL_TIME now = ossl_time_now(); 1344 1345 *gen_new_token = 0; 1346 1347 if (!decrypt_validation_token(port, hdr->token, hdr->token_len, NULL, 1348 &dec_token_len) 1349 || dec_token_len > MARSHALLED_TOKEN_MAX_LEN 1350 || !decrypt_validation_token(port, hdr->token, hdr->token_len, 1351 dec_token, &dec_token_len) 1352 || !parse_validation_token(&token, dec_token, dec_token_len)) 1353 goto err; 1354 1355 /* 1356 * Validate token timestamp. Current time should not be before the token 1357 * timestamp. 1358 */ 1359 if (ossl_time_compare(now, token.timestamp) < 0) 1360 goto err; 1361 time_diff = ossl_time2seconds(ossl_time_abs_difference(token.timestamp, 1362 now)); 1363 if ((token.is_retry && time_diff > RETRY_LIFETIME) 1364 || (!token.is_retry && time_diff > NEW_TOKEN_LIFETIME)) 1365 goto err; 1366 1367 /* Validate remote address */ 1368 if (!BIO_ADDR_rawaddress(peer, NULL, &remote_addr_len) 1369 || remote_addr_len != token.remote_addr_len 1370 || (remote_addr = OPENSSL_malloc(remote_addr_len)) == NULL 1371 || !BIO_ADDR_rawaddress(peer, remote_addr, &remote_addr_len) 1372 || memcmp(remote_addr, token.remote_addr, remote_addr_len) != 0) 1373 goto err; 1374 1375 /* 1376 * Set ODCID and SCID. If the token is from a RETRY packet, retrieve both 1377 * from the token. Otherwise, generate a new ODCID and use the header's 1378 * source connection ID for SCID. 1379 */ 1380 if (token.is_retry) { 1381 /* 1382 * We're parsing a packet header before its gone through AEAD validation 1383 * here, so there is a chance we are dealing with corrupted data. Make 1384 * Sure the dcid encoded in the token matches the headers dcid to 1385 * mitigate that. 1386 * TODO(QUIC FUTURE): Consider handling AEAD validation at the port 1387 * level rather than the QRX/channel level to eliminate the need for 1388 * this. 1389 */ 1390 if (token.rscid.id_len != hdr->dst_conn_id.id_len 1391 || memcmp(&token.rscid.id, &hdr->dst_conn_id.id, 1392 token.rscid.id_len) 1393 != 0) 1394 goto err; 1395 *odcid = token.odcid; 1396 *scid = token.rscid; 1397 } else { 1398 if (!ossl_quic_lcidm_get_unused_cid(port->lcidm, odcid)) 1399 goto err; 1400 *scid = hdr->src_conn_id; 1401 } 1402 1403 /* 1404 * Determine if we need to send a NEW_TOKEN frame 1405 * If we validated a retry token, we should always 1406 * send a NEW_TOKEN frame to the client 1407 * 1408 * If however, we validated a NEW_TOKEN, which may be 1409 * reused multiple times, only send a NEW_TOKEN frame 1410 * if the existing received token has less than 10% of its lifetime 1411 * remaining. This prevents us from constantly sending 1412 * NEW_TOKEN frames on every connection when not needed 1413 */ 1414 if (token.is_retry) { 1415 *gen_new_token = 1; 1416 } else { 1417 if (time_diff > ((NEW_TOKEN_LIFETIME * 9) / 10)) 1418 *gen_new_token = 1; 1419 } 1420 1421 ret = 1; 1422 err: 1423 cleanup_validation_token(&token); 1424 OPENSSL_free(remote_addr); 1425 return ret; 1426 } 1427 1428 static void generate_new_token(QUIC_CHANNEL *ch, BIO_ADDR *peer) 1429 { 1430 QUIC_CONN_ID rscid = { 0 }; 1431 QUIC_VALIDATION_TOKEN token; 1432 unsigned char buffer[ENCRYPTED_TOKEN_MAX_LEN]; 1433 unsigned char *ct_buf; 1434 size_t ct_len; 1435 size_t token_buf_len = 0; 1436 1437 /* Clients never send a NEW_TOKEN */ 1438 if (!ch->is_server) 1439 return; 1440 1441 ct_buf = OPENSSL_zalloc(ENCRYPTED_TOKEN_MAX_LEN); 1442 if (ct_buf == NULL) 1443 return; 1444 1445 /* 1446 * NEW_TOKEN tokens may be used for multiple subsequent connections 1447 * within their timeout period, so don't reserve an rscid here 1448 * like we do for retry tokens, instead, just fill it with random 1449 * data, as we won't use it anyway 1450 */ 1451 rscid.id_len = 8; 1452 if (!RAND_bytes_ex(ch->port->engine->libctx, rscid.id, 8, 0)) { 1453 OPENSSL_free(ct_buf); 1454 return; 1455 } 1456 1457 memset(&token, 0, sizeof(QUIC_VALIDATION_TOKEN)); 1458 1459 if (!generate_token(peer, ch->init_dcid, rscid, &token, 0) 1460 || !marshal_validation_token(&token, buffer, &token_buf_len) 1461 || !encrypt_validation_token(ch->port, buffer, token_buf_len, NULL, 1462 &ct_len) 1463 || ct_len > ENCRYPTED_TOKEN_MAX_LEN 1464 || !encrypt_validation_token(ch->port, buffer, token_buf_len, ct_buf, 1465 &ct_len) 1466 || !ossl_assert(ct_len >= QUIC_RETRY_INTEGRITY_TAG_LEN)) { 1467 OPENSSL_free(ct_buf); 1468 cleanup_validation_token(&token); 1469 return; 1470 } 1471 1472 ch->pending_new_token = ct_buf; 1473 ch->pending_new_token_len = ct_len; 1474 1475 cleanup_validation_token(&token); 1476 } 1477 1478 /* 1479 * This is called by the demux when we get a packet not destined for any known 1480 * DCID. 1481 */ 1482 static void port_default_packet_handler(QUIC_URXE *e, void *arg, 1483 const QUIC_CONN_ID *dcid) 1484 { 1485 QUIC_PORT *port = arg; 1486 PACKET pkt; 1487 QUIC_PKT_HDR hdr; 1488 QUIC_CHANNEL *ch = NULL, *new_ch = NULL; 1489 QUIC_CONN_ID odcid, scid; 1490 uint8_t gen_new_token = 0; 1491 OSSL_QRX *qrx = NULL; 1492 OSSL_QRX *qrx_src = NULL; 1493 OSSL_QRX_ARGS qrx_args = { 0 }; 1494 uint64_t cause_flags = 0; 1495 OSSL_QRX_PKT *qrx_pkt = NULL; 1496 1497 /* Don't handle anything if we are no longer running. */ 1498 if (!ossl_quic_port_is_running(port)) 1499 goto undesirable; 1500 1501 if (port_try_handle_stateless_reset(port, e)) 1502 goto undesirable; 1503 1504 if (dcid != NULL 1505 && ossl_quic_lcidm_lookup(port->lcidm, dcid, NULL, 1506 (void **)&ch)) { 1507 assert(ch != NULL); 1508 ossl_quic_channel_inject(ch, e); 1509 return; 1510 } 1511 1512 /* 1513 * If we have an incoming packet which doesn't match any existing connection 1514 * we assume this is an attempt to make a new connection. 1515 */ 1516 if (!port->allow_incoming) 1517 goto undesirable; 1518 1519 /* 1520 * We have got a packet for an unknown DCID. This might be an attempt to 1521 * open a new connection. 1522 */ 1523 if (e->data_len < QUIC_MIN_INITIAL_DGRAM_LEN) 1524 goto undesirable; 1525 1526 if (!PACKET_buf_init(&pkt, ossl_quic_urxe_data(e), e->data_len)) 1527 goto undesirable; 1528 1529 /* 1530 * We set short_conn_id_len to SIZE_MAX here which will cause the decode 1531 * operation to fail if we get a 1-RTT packet. This is fine since we only 1532 * care about Initial packets. 1533 */ 1534 if (!ossl_quic_wire_decode_pkt_hdr(&pkt, SIZE_MAX, 1, 0, &hdr, NULL, 1535 &cause_flags)) { 1536 /* 1537 * If we fail due to a bad version, we know the packet up to the version 1538 * number was decoded, and we use it below to send a version 1539 * negotiation packet 1540 */ 1541 if ((cause_flags & QUIC_PKT_HDR_DECODE_BAD_VERSION) == 0) 1542 goto undesirable; 1543 } 1544 1545 switch (hdr.version) { 1546 case QUIC_VERSION_1: 1547 break; 1548 1549 case QUIC_VERSION_NONE: 1550 default: 1551 1552 /* 1553 * If we get here, then we have a bogus version, and might need 1554 * to send a version negotiation packet. According to 1555 * RFC 9000 s. 6 and 14.1, we only do so however, if the UDP datagram 1556 * is a minimum of 1200 bytes in size 1557 */ 1558 if (e->data_len < 1200) 1559 goto undesirable; 1560 1561 /* 1562 * If we don't get a supported version, respond with a ver 1563 * negotiation packet, and discard 1564 * TODO(QUIC FUTURE): Rate limit the reception of these 1565 */ 1566 port_send_version_negotiation(port, &e->peer, &hdr); 1567 goto undesirable; 1568 } 1569 1570 /* 1571 * We only care about Initial packets which might be trying to establish a 1572 * connection. 1573 */ 1574 if (hdr.type != QUIC_PKT_TYPE_INITIAL) 1575 goto undesirable; 1576 1577 odcid.id_len = 0; 1578 1579 /* 1580 * Create qrx now so we can check integrity of packet 1581 * which does not belong to any channel. 1582 */ 1583 qrx_args.libctx = port->engine->libctx; 1584 qrx_args.demux = port->demux; 1585 qrx_args.short_conn_id_len = dcid->id_len; 1586 qrx_args.max_deferred = 32; 1587 qrx = ossl_qrx_new(&qrx_args); 1588 if (qrx == NULL) 1589 goto undesirable; 1590 1591 /* 1592 * Derive secrets for qrx only. 1593 */ 1594 if (!ossl_quic_provide_initial_secret(port->engine->libctx, 1595 port->engine->propq, 1596 &hdr.dst_conn_id, 1597 /* is_server */ 1, 1598 qrx, NULL)) 1599 goto undesirable; 1600 1601 if (ossl_qrx_validate_initial_packet(qrx, e, (const QUIC_CONN_ID *)dcid) == 0) 1602 goto undesirable; 1603 1604 if (port->validate_addr == 0) { 1605 /* 1606 * Forget qrx, because it becomes (almost) useless here. We must let 1607 * channel to create a new QRX for connection ID server chooses. The 1608 * validation keys for new DCID will be derived by 1609 * ossl_quic_channel_on_new_conn() when we will be creating channel. 1610 * See RFC 9000 section 7.2 negotiating connection id to better 1611 * understand what's going on here. 1612 * 1613 * Did we say qrx is almost useless? Why? Because qrx remembers packets 1614 * we just validated. Those packets must be injected to channel we are 1615 * going to create. We use qrx_src alias so we can read packets from 1616 * qrx and inject them to channel. 1617 */ 1618 qrx_src = qrx; 1619 qrx = NULL; 1620 } 1621 /* 1622 * TODO(QUIC FUTURE): there should be some logic similar to accounting half-open 1623 * states in TCP. If we reach certain threshold, then we want to 1624 * validate clients. 1625 */ 1626 if (port->validate_addr == 1 && hdr.token == NULL) { 1627 port_send_retry(port, &e->peer, &hdr); 1628 goto undesirable; 1629 } 1630 1631 /* 1632 * Note, even if we don't enforce the sending of retry frames for 1633 * server address validation, we may still get a token if we sent 1634 * a NEW_TOKEN frame during a prior connection, which we should still 1635 * validate here 1636 */ 1637 if (hdr.token != NULL 1638 && port_validate_token(&hdr, port, &e->peer, 1639 &odcid, &scid, 1640 &gen_new_token) 1641 == 0) { 1642 /* 1643 * RFC 9000 s 8.1.3 1644 * When a server receives an Initial packet with an address 1645 * validation token, it MUST attempt to validate the token, 1646 * unless it has already completed address validation. 1647 * If the token is invalid, then the server SHOULD proceed as 1648 * if the client did not have a validated address, 1649 * including potentially sending a Retry packet 1650 * Note: If address validation is disabled, just act like 1651 * the request is valid 1652 */ 1653 if (port->validate_addr == 1) { 1654 /* 1655 * Again: we should consider saving initial encryption level 1656 * secrets to token here to save some CPU cycles. 1657 */ 1658 port_send_retry(port, &e->peer, &hdr); 1659 goto undesirable; 1660 } 1661 1662 /* 1663 * client is under amplification limit, until it completes 1664 * handshake. 1665 * 1666 * forget qrx so channel can create a new one 1667 * with valid initial encryption level keys. 1668 */ 1669 qrx_src = qrx; 1670 qrx = NULL; 1671 } 1672 1673 port_bind_channel(port, &e->peer, &scid, &hdr.dst_conn_id, 1674 &odcid, qrx, &new_ch); 1675 1676 /* 1677 * if packet validates it gets moved to channel, we've just bound 1678 * to port. 1679 */ 1680 if (new_ch == NULL) 1681 goto undesirable; 1682 1683 /* 1684 * Generate a token for sending in a later NEW_TOKEN frame 1685 */ 1686 if (gen_new_token == 1) 1687 generate_new_token(new_ch, &e->peer); 1688 1689 if (qrx != NULL) { 1690 /* 1691 * The qrx belongs to channel now, so don't free it. 1692 */ 1693 qrx = NULL; 1694 } else { 1695 /* 1696 * We still need to salvage packets from almost forgotten qrx 1697 * and pass them to channel. 1698 */ 1699 while (ossl_qrx_read_pkt(qrx_src, &qrx_pkt) == 1) 1700 ossl_quic_channel_inject_pkt(new_ch, qrx_pkt); 1701 ossl_qrx_update_pn_space(qrx_src, new_ch->qrx); 1702 } 1703 1704 /* 1705 * If function reaches this place, then packet got validated in 1706 * ossl_qrx_validate_initial_packet(). Keep in mind the function 1707 * ossl_qrx_validate_initial_packet() decrypts the packet to validate it. 1708 * If packet validation was successful (and it was because we are here), 1709 * then the function puts the packet to qrx->rx_pending. We must not call 1710 * ossl_qrx_inject_urxe() here now, because we don't want to insert 1711 * the packet to qrx->urx_pending which keeps packet waiting for decryption. 1712 * 1713 * We are going to call ossl_quic_demux_release_urxe() to dispose buffer 1714 * which still holds encrypted data. 1715 */ 1716 1717 undesirable: 1718 ossl_qrx_free(qrx); 1719 ossl_qrx_free(qrx_src); 1720 ossl_quic_demux_release_urxe(port->demux, e); 1721 } 1722 1723 void ossl_quic_port_raise_net_error(QUIC_PORT *port, 1724 QUIC_CHANNEL *triggering_ch) 1725 { 1726 QUIC_CHANNEL *ch; 1727 1728 if (!ossl_quic_port_is_running(port)) 1729 return; 1730 1731 /* 1732 * Immediately capture any triggering error on the error stack, with a 1733 * cover error. 1734 */ 1735 ERR_raise_data(ERR_LIB_SSL, SSL_R_QUIC_NETWORK_ERROR, 1736 "port failed due to network BIO I/O error"); 1737 OSSL_ERR_STATE_save(port->err_state); 1738 1739 port_transition_failed(port); 1740 1741 /* Give the triggering channel (if any) the first notification. */ 1742 if (triggering_ch != NULL) 1743 ossl_quic_channel_raise_net_error(triggering_ch); 1744 1745 OSSL_LIST_FOREACH(ch, ch, &port->channel_list) 1746 if (ch != triggering_ch) 1747 ossl_quic_channel_raise_net_error(ch); 1748 } 1749 1750 void ossl_quic_port_restore_err_state(const QUIC_PORT *port) 1751 { 1752 ERR_clear_error(); 1753 OSSL_ERR_STATE_restore(port->err_state); 1754 } 1755