1/* 2 * Copyright 2005-2023 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 <stdio.h> 11#include <errno.h> 12#include "../ssl_local.h" 13#include <openssl/evp.h> 14#include <openssl/buffer.h> 15#include "record_local.h" 16#include "internal/packet.h" 17#include "internal/cryptlib.h" 18 19int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl) 20{ 21 DTLS_RECORD_LAYER *d; 22 23 if ((d = OPENSSL_malloc(sizeof(*d))) == NULL) { 24 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE); 25 return 0; 26 } 27 28 rl->d = d; 29 30 d->unprocessed_rcds.q = pqueue_new(); 31 d->processed_rcds.q = pqueue_new(); 32 d->buffered_app_data.q = pqueue_new(); 33 34 if (d->unprocessed_rcds.q == NULL || d->processed_rcds.q == NULL 35 || d->buffered_app_data.q == NULL) { 36 pqueue_free(d->unprocessed_rcds.q); 37 pqueue_free(d->processed_rcds.q); 38 pqueue_free(d->buffered_app_data.q); 39 OPENSSL_free(d); 40 rl->d = NULL; 41 return 0; 42 } 43 44 return 1; 45} 46 47void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl) 48{ 49 if (rl->d == NULL) 50 return; 51 52 DTLS_RECORD_LAYER_clear(rl); 53 pqueue_free(rl->d->unprocessed_rcds.q); 54 pqueue_free(rl->d->processed_rcds.q); 55 pqueue_free(rl->d->buffered_app_data.q); 56 OPENSSL_free(rl->d); 57 rl->d = NULL; 58} 59 60void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl) 61{ 62 DTLS_RECORD_LAYER *d; 63 pitem *item = NULL; 64 DTLS1_RECORD_DATA *rdata; 65 pqueue *unprocessed_rcds; 66 pqueue *processed_rcds; 67 pqueue *buffered_app_data; 68 69 d = rl->d; 70 71 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) { 72 rdata = (DTLS1_RECORD_DATA *)item->data; 73 OPENSSL_free(rdata->rbuf.buf); 74 OPENSSL_free(item->data); 75 pitem_free(item); 76 } 77 78 while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) { 79 rdata = (DTLS1_RECORD_DATA *)item->data; 80 if (rl->s->options & SSL_OP_CLEANSE_PLAINTEXT) 81 OPENSSL_cleanse(rdata->rbuf.buf, rdata->rbuf.len); 82 OPENSSL_free(rdata->rbuf.buf); 83 OPENSSL_free(item->data); 84 pitem_free(item); 85 } 86 87 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) { 88 rdata = (DTLS1_RECORD_DATA *)item->data; 89 if (rl->s->options & SSL_OP_CLEANSE_PLAINTEXT) 90 OPENSSL_cleanse(rdata->rbuf.buf, rdata->rbuf.len); 91 OPENSSL_free(rdata->rbuf.buf); 92 OPENSSL_free(item->data); 93 pitem_free(item); 94 } 95 96 unprocessed_rcds = d->unprocessed_rcds.q; 97 processed_rcds = d->processed_rcds.q; 98 buffered_app_data = d->buffered_app_data.q; 99 memset(d, 0, sizeof(*d)); 100 d->unprocessed_rcds.q = unprocessed_rcds; 101 d->processed_rcds.q = processed_rcds; 102 d->buffered_app_data.q = buffered_app_data; 103} 104 105void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e) 106{ 107 if (e == rl->d->w_epoch - 1) { 108 memcpy(rl->d->curr_write_sequence, 109 rl->write_sequence, sizeof(rl->write_sequence)); 110 memcpy(rl->write_sequence, 111 rl->d->last_write_sequence, sizeof(rl->write_sequence)); 112 } else if (e == rl->d->w_epoch + 1) { 113 memcpy(rl->d->last_write_sequence, 114 rl->write_sequence, sizeof(unsigned char[8])); 115 memcpy(rl->write_sequence, 116 rl->d->curr_write_sequence, sizeof(rl->write_sequence)); 117 } 118 rl->d->w_epoch = e; 119} 120 121void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq) 122{ 123 memcpy(rl->write_sequence, seq, SEQ_NUM_SIZE); 124} 125 126/* copy buffered record into SSL structure */ 127static int dtls1_copy_record(SSL *s, pitem *item) 128{ 129 DTLS1_RECORD_DATA *rdata; 130 131 rdata = (DTLS1_RECORD_DATA *)item->data; 132 133 SSL3_BUFFER_release(&s->rlayer.rbuf); 134 135 s->rlayer.packet = rdata->packet; 136 s->rlayer.packet_length = rdata->packet_length; 137 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER)); 138 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD)); 139 140 /* Set proper sequence number for mac calculation */ 141 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6); 142 143 return 1; 144} 145 146int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority) 147{ 148 DTLS1_RECORD_DATA *rdata; 149 pitem *item; 150 151 /* Limit the size of the queue to prevent DOS attacks */ 152 if (pqueue_size(queue->q) >= 100) 153 return 0; 154 155 rdata = OPENSSL_malloc(sizeof(*rdata)); 156 item = pitem_new(priority, rdata); 157 if (rdata == NULL || item == NULL) { 158 OPENSSL_free(rdata); 159 pitem_free(item); 160 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 161 return -1; 162 } 163 164 rdata->packet = s->rlayer.packet; 165 rdata->packet_length = s->rlayer.packet_length; 166 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER)); 167 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD)); 168 169 item->data = rdata; 170 171#ifndef OPENSSL_NO_SCTP 172 /* Store bio_dgram_sctp_rcvinfo struct */ 173 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 174 (SSL_get_state(s) == TLS_ST_SR_FINISHED 175 || SSL_get_state(s) == TLS_ST_CR_FINISHED)) { 176 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, 177 sizeof(rdata->recordinfo), &rdata->recordinfo); 178 } 179#endif 180 181 s->rlayer.packet = NULL; 182 s->rlayer.packet_length = 0; 183 memset(&s->rlayer.rbuf, 0, sizeof(s->rlayer.rbuf)); 184 memset(&s->rlayer.rrec, 0, sizeof(s->rlayer.rrec)); 185 186 if (!ssl3_setup_buffers(s)) { 187 /* SSLfatal() already called */ 188 OPENSSL_free(rdata->rbuf.buf); 189 OPENSSL_free(rdata); 190 pitem_free(item); 191 return -1; 192 } 193 194 if (pqueue_insert(queue->q, item) == NULL) { 195 /* Must be a duplicate so ignore it */ 196 OPENSSL_free(rdata->rbuf.buf); 197 OPENSSL_free(rdata); 198 pitem_free(item); 199 } 200 201 return 1; 202} 203 204int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue) 205{ 206 pitem *item; 207 208 item = pqueue_pop(queue->q); 209 if (item) { 210 dtls1_copy_record(s, item); 211 212 OPENSSL_free(item->data); 213 pitem_free(item); 214 215 return 1; 216 } 217 218 return 0; 219} 220 221/* 222 * retrieve a buffered record that belongs to the new epoch, i.e., not 223 * processed yet 224 */ 225#define dtls1_get_unprocessed_record(s) \ 226 dtls1_retrieve_buffered_record((s), \ 227 &((s)->rlayer.d->unprocessed_rcds)) 228 229int dtls1_process_buffered_records(SSL *s) 230{ 231 pitem *item; 232 SSL3_BUFFER *rb; 233 SSL3_RECORD *rr; 234 DTLS1_BITMAP *bitmap; 235 unsigned int is_next_epoch; 236 int replayok = 1; 237 238 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q); 239 if (item) { 240 /* Check if epoch is current. */ 241 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch) 242 return 1; /* Nothing to do. */ 243 244 rr = RECORD_LAYER_get_rrec(&s->rlayer); 245 246 rb = RECORD_LAYER_get_rbuf(&s->rlayer); 247 248 if (SSL3_BUFFER_get_left(rb) > 0) { 249 /* 250 * We've still got data from the current packet to read. There could 251 * be a record from the new epoch in it - so don't overwrite it 252 * with the unprocessed records yet (we'll do it when we've 253 * finished reading the current packet). 254 */ 255 return 1; 256 } 257 258 /* Process all the records. */ 259 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) { 260 dtls1_get_unprocessed_record(s); 261 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch); 262 if (bitmap == NULL) { 263 /* 264 * Should not happen. This will only ever be NULL when the 265 * current record is from a different epoch. But that cannot 266 * be the case because we already checked the epoch above 267 */ 268 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 269 return 0; 270 } 271#ifndef OPENSSL_NO_SCTP 272 /* Only do replay check if no SCTP bio */ 273 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) 274#endif 275 { 276 /* 277 * Check whether this is a repeat, or aged record. We did this 278 * check once already when we first received the record - but 279 * we might have updated the window since then due to 280 * records we subsequently processed. 281 */ 282 replayok = dtls1_record_replay_check(s, bitmap); 283 } 284 285 if (!replayok || !dtls1_process_record(s, bitmap)) { 286 if (ossl_statem_in_error(s)) { 287 /* dtls1_process_record called SSLfatal() */ 288 return 0; 289 } 290 /* dump this record */ 291 rr->length = 0; 292 RECORD_LAYER_reset_packet_length(&s->rlayer); 293 continue; 294 } 295 296 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds), 297 SSL3_RECORD_get_seq_num(s->rlayer.rrec)) < 0) { 298 /* SSLfatal() already called */ 299 return 0; 300 } 301 } 302 } 303 304 /* 305 * sync epoch numbers once all the unprocessed records have been 306 * processed 307 */ 308 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch; 309 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1; 310 311 return 1; 312} 313 314/*- 315 * Return up to 'len' payload bytes received in 'type' records. 316 * 'type' is one of the following: 317 * 318 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 319 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 320 * - 0 (during a shutdown, no data has to be returned) 321 * 322 * If we don't have stored data to work from, read a SSL/TLS record first 323 * (possibly multiple records if we still don't have anything to return). 324 * 325 * This function must handle any surprises the peer may have for us, such as 326 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec 327 * messages are treated as if they were handshake messages *if* the |recd_type| 328 * argument is non NULL. 329 * Also if record payloads contain fragments too small to process, we store 330 * them until there is enough for the respective protocol (the record protocol 331 * may use arbitrary fragmentation and even interleaving): 332 * Change cipher spec protocol 333 * just 1 byte needed, no need for keeping anything stored 334 * Alert protocol 335 * 2 bytes needed (AlertLevel, AlertDescription) 336 * Handshake protocol 337 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 338 * to detect unexpected Client Hello and Hello Request messages 339 * here, anything else is handled by higher layers 340 * Application data protocol 341 * none of our business 342 */ 343int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf, 344 size_t len, int peek, size_t *readbytes) 345{ 346 int i, j, iret; 347 size_t n; 348 SSL3_RECORD *rr; 349 void (*cb) (const SSL *ssl, int type2, int val) = NULL; 350 351 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) { 352 /* Not initialized yet */ 353 if (!ssl3_setup_buffers(s)) { 354 /* SSLfatal() already called */ 355 return -1; 356 } 357 } 358 359 if ((type && (type != SSL3_RT_APPLICATION_DATA) && 360 (type != SSL3_RT_HANDSHAKE)) || 361 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 362 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 363 return -1; 364 } 365 366 if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s)) { 367 /* type == SSL3_RT_APPLICATION_DATA */ 368 i = s->handshake_func(s); 369 /* SSLfatal() already called if appropriate */ 370 if (i < 0) 371 return i; 372 if (i == 0) 373 return -1; 374 } 375 376 start: 377 s->rwstate = SSL_NOTHING; 378 379 /*- 380 * s->s3.rrec.type - is the type of record 381 * s->s3.rrec.data, - data 382 * s->s3.rrec.off, - offset into 'data' for next read 383 * s->s3.rrec.length, - number of bytes. 384 */ 385 rr = s->rlayer.rrec; 386 387 /* 388 * We are not handshaking and have no data yet, so process data buffered 389 * during the last handshake in advance, if any. 390 */ 391 if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) { 392 pitem *item; 393 item = pqueue_pop(s->rlayer.d->buffered_app_data.q); 394 if (item) { 395#ifndef OPENSSL_NO_SCTP 396 /* Restore bio_dgram_sctp_rcvinfo struct */ 397 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) { 398 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data; 399 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, 400 sizeof(rdata->recordinfo), &rdata->recordinfo); 401 } 402#endif 403 404 dtls1_copy_record(s, item); 405 406 OPENSSL_free(item->data); 407 pitem_free(item); 408 } 409 } 410 411 /* Check for timeout */ 412 if (dtls1_handle_timeout(s) > 0) { 413 goto start; 414 } else if (ossl_statem_in_error(s)) { 415 /* dtls1_handle_timeout() has failed with a fatal error */ 416 return -1; 417 } 418 419 /* get new packet if necessary */ 420 if ((SSL3_RECORD_get_length(rr) == 0) 421 || (s->rlayer.rstate == SSL_ST_READ_BODY)) { 422 RECORD_LAYER_set_numrpipes(&s->rlayer, 0); 423 iret = dtls1_get_record(s); 424 if (iret <= 0) { 425 iret = dtls1_read_failed(s, iret); 426 /* 427 * Anything other than a timeout is an error. SSLfatal() already 428 * called if appropriate. 429 */ 430 if (iret <= 0) 431 return iret; 432 else 433 goto start; 434 } 435 RECORD_LAYER_set_numrpipes(&s->rlayer, 1); 436 } 437 438 /* 439 * Reset the count of consecutive warning alerts if we've got a non-empty 440 * record that isn't an alert. 441 */ 442 if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT 443 && SSL3_RECORD_get_length(rr) != 0) 444 s->rlayer.alert_count = 0; 445 446 /* we now have a packet which can be read and processed */ 447 448 if (s->s3.change_cipher_spec /* set when we receive ChangeCipherSpec, 449 * reset by ssl3_get_finished */ 450 && (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) { 451 /* 452 * We now have application data between CCS and Finished. Most likely 453 * the packets were reordered on their way, so buffer the application 454 * data for later processing rather than dropping the connection. 455 */ 456 if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data), 457 SSL3_RECORD_get_seq_num(rr)) < 0) { 458 /* SSLfatal() already called */ 459 return -1; 460 } 461 SSL3_RECORD_set_length(rr, 0); 462 SSL3_RECORD_set_read(rr); 463 goto start; 464 } 465 466 /* 467 * If the other end has shut down, throw anything we read away (even in 468 * 'peek' mode) 469 */ 470 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 471 SSL3_RECORD_set_length(rr, 0); 472 SSL3_RECORD_set_read(rr); 473 s->rwstate = SSL_NOTHING; 474 return 0; 475 } 476 477 if (type == SSL3_RECORD_get_type(rr) 478 || (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC 479 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) { 480 /* 481 * SSL3_RT_APPLICATION_DATA or 482 * SSL3_RT_HANDSHAKE or 483 * SSL3_RT_CHANGE_CIPHER_SPEC 484 */ 485 /* 486 * make sure that we are not getting application data when we are 487 * doing a handshake for the first time 488 */ 489 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 490 (s->enc_read_ctx == NULL)) { 491 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, 492 SSL_R_APP_DATA_IN_HANDSHAKE); 493 return -1; 494 } 495 496 if (recvd_type != NULL) 497 *recvd_type = SSL3_RECORD_get_type(rr); 498 499 if (len == 0) { 500 /* 501 * Mark a zero length record as read. This ensures multiple calls to 502 * SSL_read() with a zero length buffer will eventually cause 503 * SSL_pending() to report data as being available. 504 */ 505 if (SSL3_RECORD_get_length(rr) == 0) 506 SSL3_RECORD_set_read(rr); 507 return 0; 508 } 509 510 if (len > SSL3_RECORD_get_length(rr)) 511 n = SSL3_RECORD_get_length(rr); 512 else 513 n = len; 514 515 memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n); 516 if (peek) { 517 if (SSL3_RECORD_get_length(rr) == 0) 518 SSL3_RECORD_set_read(rr); 519 } else { 520 if (s->options & SSL_OP_CLEANSE_PLAINTEXT) 521 OPENSSL_cleanse(&(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n); 522 SSL3_RECORD_sub_length(rr, n); 523 SSL3_RECORD_add_off(rr, n); 524 if (SSL3_RECORD_get_length(rr) == 0) { 525 s->rlayer.rstate = SSL_ST_READ_HEADER; 526 SSL3_RECORD_set_off(rr, 0); 527 SSL3_RECORD_set_read(rr); 528 } 529 } 530#ifndef OPENSSL_NO_SCTP 531 /* 532 * We might had to delay a close_notify alert because of reordered 533 * app data. If there was an alert and there is no message to read 534 * anymore, finally set shutdown. 535 */ 536 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 537 s->d1->shutdown_received 538 && BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) <= 0) { 539 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 540 return 0; 541 } 542#endif 543 *readbytes = n; 544 return 1; 545 } 546 547 /* 548 * If we get here, then type != rr->type; if we have a handshake message, 549 * then it was unexpected (Hello Request or Client Hello). 550 */ 551 552 if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) { 553 unsigned int alert_level, alert_descr; 554 unsigned char *alert_bytes = SSL3_RECORD_get_data(rr) 555 + SSL3_RECORD_get_off(rr); 556 PACKET alert; 557 558 if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr)) 559 || !PACKET_get_1(&alert, &alert_level) 560 || !PACKET_get_1(&alert, &alert_descr) 561 || PACKET_remaining(&alert) != 0) { 562 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_INVALID_ALERT); 563 return -1; 564 } 565 566 if (s->msg_callback) 567 s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 2, s, 568 s->msg_callback_arg); 569 570 if (s->info_callback != NULL) 571 cb = s->info_callback; 572 else if (s->ctx->info_callback != NULL) 573 cb = s->ctx->info_callback; 574 575 if (cb != NULL) { 576 j = (alert_level << 8) | alert_descr; 577 cb(s, SSL_CB_READ_ALERT, j); 578 } 579 580 if (alert_level == SSL3_AL_WARNING) { 581 s->s3.warn_alert = alert_descr; 582 SSL3_RECORD_set_read(rr); 583 584 s->rlayer.alert_count++; 585 if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) { 586 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, 587 SSL_R_TOO_MANY_WARN_ALERTS); 588 return -1; 589 } 590 591 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 592#ifndef OPENSSL_NO_SCTP 593 /* 594 * With SCTP and streams the socket may deliver app data 595 * after a close_notify alert. We have to check this first so 596 * that nothing gets discarded. 597 */ 598 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && 599 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) > 0) { 600 s->d1->shutdown_received = 1; 601 s->rwstate = SSL_READING; 602 BIO_clear_retry_flags(SSL_get_rbio(s)); 603 BIO_set_retry_read(SSL_get_rbio(s)); 604 return -1; 605 } 606#endif 607 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 608 return 0; 609 } 610 } else if (alert_level == SSL3_AL_FATAL) { 611 s->rwstate = SSL_NOTHING; 612 s->s3.fatal_alert = alert_descr; 613 SSLfatal_data(s, SSL_AD_NO_ALERT, 614 SSL_AD_REASON_OFFSET + alert_descr, 615 "SSL alert number %d", alert_descr); 616 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 617 SSL3_RECORD_set_read(rr); 618 SSL_CTX_remove_session(s->session_ctx, s->session); 619 return 0; 620 } else { 621 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_UNKNOWN_ALERT_TYPE); 622 return -1; 623 } 624 625 goto start; 626 } 627 628 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a 629 * shutdown */ 630 s->rwstate = SSL_NOTHING; 631 SSL3_RECORD_set_length(rr, 0); 632 SSL3_RECORD_set_read(rr); 633 return 0; 634 } 635 636 if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) { 637 /* 638 * We can't process a CCS now, because previous handshake messages 639 * are still missing, so just drop it. 640 */ 641 SSL3_RECORD_set_length(rr, 0); 642 SSL3_RECORD_set_read(rr); 643 goto start; 644 } 645 646 /* 647 * Unexpected handshake message (Client Hello, or protocol violation) 648 */ 649 if ((SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) && 650 !ossl_statem_get_in_handshake(s)) { 651 struct hm_header_st msg_hdr; 652 653 /* 654 * This may just be a stale retransmit. Also sanity check that we have 655 * at least enough record bytes for a message header 656 */ 657 if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch 658 || SSL3_RECORD_get_length(rr) < DTLS1_HM_HEADER_LENGTH) { 659 SSL3_RECORD_set_length(rr, 0); 660 SSL3_RECORD_set_read(rr); 661 goto start; 662 } 663 664 dtls1_get_message_header(rr->data, &msg_hdr); 665 666 /* 667 * If we are server, we may have a repeated FINISHED of the client 668 * here, then retransmit our CCS and FINISHED. 669 */ 670 if (msg_hdr.type == SSL3_MT_FINISHED) { 671 if (dtls1_check_timeout_num(s) < 0) { 672 /* SSLfatal) already called */ 673 return -1; 674 } 675 676 if (dtls1_retransmit_buffered_messages(s) <= 0) { 677 /* Fail if we encountered a fatal error */ 678 if (ossl_statem_in_error(s)) 679 return -1; 680 } 681 SSL3_RECORD_set_length(rr, 0); 682 SSL3_RECORD_set_read(rr); 683 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 684 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) { 685 /* no read-ahead left? */ 686 BIO *bio; 687 688 s->rwstate = SSL_READING; 689 bio = SSL_get_rbio(s); 690 BIO_clear_retry_flags(bio); 691 BIO_set_retry_read(bio); 692 return -1; 693 } 694 } 695 goto start; 696 } 697 698 /* 699 * To get here we must be trying to read app data but found handshake 700 * data. But if we're trying to read app data, and we're not in init 701 * (which is tested for at the top of this function) then init must be 702 * finished 703 */ 704 if (!ossl_assert(SSL_is_init_finished(s))) { 705 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 706 return -1; 707 } 708 709 /* We found handshake data, so we're going back into init */ 710 ossl_statem_set_in_init(s, 1); 711 712 i = s->handshake_func(s); 713 /* SSLfatal() called if appropriate */ 714 if (i < 0) 715 return i; 716 if (i == 0) 717 return -1; 718 719 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 720 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) { 721 /* no read-ahead left? */ 722 BIO *bio; 723 /* 724 * In the case where we try to read application data, but we 725 * trigger an SSL handshake, we return -1 with the retry 726 * option set. Otherwise renegotiation may cause nasty 727 * problems in the blocking world 728 */ 729 s->rwstate = SSL_READING; 730 bio = SSL_get_rbio(s); 731 BIO_clear_retry_flags(bio); 732 BIO_set_retry_read(bio); 733 return -1; 734 } 735 } 736 goto start; 737 } 738 739 switch (SSL3_RECORD_get_type(rr)) { 740 default: 741 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD); 742 return -1; 743 case SSL3_RT_CHANGE_CIPHER_SPEC: 744 case SSL3_RT_ALERT: 745 case SSL3_RT_HANDSHAKE: 746 /* 747 * we already handled all of these, with the possible exception of 748 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but 749 * that should not happen when type != rr->type 750 */ 751 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, ERR_R_INTERNAL_ERROR); 752 return -1; 753 case SSL3_RT_APPLICATION_DATA: 754 /* 755 * At this point, we were expecting handshake data, but have 756 * application data. If the library was running inside ssl3_read() 757 * (i.e. in_read_app_data is set) and it makes sense to read 758 * application data at this point (session renegotiation not yet 759 * started), we will indulge it. 760 */ 761 if (s->s3.in_read_app_data && 762 (s->s3.total_renegotiations != 0) && 763 ossl_statem_app_data_allowed(s)) { 764 s->s3.in_read_app_data = 2; 765 return -1; 766 } else { 767 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD); 768 return -1; 769 } 770 } 771 /* not reached */ 772} 773 774/* 775 * Call this to write data in records of type 'type' It will return <= 0 if 776 * not all data has been sent or non-blocking IO. 777 */ 778int dtls1_write_bytes(SSL *s, int type, const void *buf, size_t len, 779 size_t *written) 780{ 781 int i; 782 783 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) { 784 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 785 return -1; 786 } 787 s->rwstate = SSL_NOTHING; 788 i = do_dtls1_write(s, type, buf, len, 0, written); 789 return i; 790} 791 792int do_dtls1_write(SSL *s, int type, const unsigned char *buf, 793 size_t len, int create_empty_fragment, size_t *written) 794{ 795 unsigned char *p, *pseq; 796 int i, mac_size, clear = 0; 797 size_t prefix_len = 0; 798 int eivlen; 799 SSL3_RECORD wr; 800 SSL3_BUFFER *wb; 801 SSL_SESSION *sess; 802 803 wb = &s->rlayer.wbuf[0]; 804 805 /* 806 * DTLS writes whole datagrams, so there can't be anything left in 807 * the buffer. 808 */ 809 if (!ossl_assert(SSL3_BUFFER_get_left(wb) == 0)) { 810 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 811 return 0; 812 } 813 814 /* If we have an alert to send, lets send it */ 815 if (s->s3.alert_dispatch) { 816 i = s->method->ssl_dispatch_alert(s); 817 if (i <= 0) 818 return i; 819 /* if it went, fall through and send more stuff */ 820 } 821 822 if (len == 0 && !create_empty_fragment) 823 return 0; 824 825 if (len > ssl_get_max_send_fragment(s)) { 826 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE); 827 return 0; 828 } 829 830 sess = s->session; 831 832 if ((sess == NULL) 833 || (s->enc_write_ctx == NULL) 834 || (EVP_MD_CTX_get0_md(s->write_hash) == NULL)) 835 clear = 1; 836 837 if (clear) 838 mac_size = 0; 839 else { 840 mac_size = EVP_MD_CTX_get_size(s->write_hash); 841 if (mac_size < 0) { 842 SSLfatal(s, SSL_AD_INTERNAL_ERROR, 843 SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE); 844 return -1; 845 } 846 } 847 848 p = SSL3_BUFFER_get_buf(wb) + prefix_len; 849 850 /* write the header */ 851 852 *(p++) = type & 0xff; 853 SSL3_RECORD_set_type(&wr, type); 854 /* 855 * Special case: for hello verify request, client version 1.0 and we 856 * haven't decided which version to use yet send back using version 1.0 857 * header: otherwise some clients will ignore it. 858 */ 859 if (s->method->version == DTLS_ANY_VERSION && 860 s->max_proto_version != DTLS1_BAD_VER) { 861 *(p++) = DTLS1_VERSION >> 8; 862 *(p++) = DTLS1_VERSION & 0xff; 863 } else { 864 *(p++) = s->version >> 8; 865 *(p++) = s->version & 0xff; 866 } 867 868 /* field where we are to write out packet epoch, seq num and len */ 869 pseq = p; 870 p += 10; 871 872 /* Explicit IV length, block ciphers appropriate version flag */ 873 if (s->enc_write_ctx) { 874 int mode = EVP_CIPHER_CTX_get_mode(s->enc_write_ctx); 875 if (mode == EVP_CIPH_CBC_MODE) { 876 eivlen = EVP_CIPHER_CTX_get_iv_length(s->enc_write_ctx); 877 if (eivlen < 0) { 878 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_LIBRARY_BUG); 879 return -1; 880 } 881 if (eivlen <= 1) 882 eivlen = 0; 883 } 884 /* Need explicit part of IV for GCM mode */ 885 else if (mode == EVP_CIPH_GCM_MODE) 886 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN; 887 else if (mode == EVP_CIPH_CCM_MODE) 888 eivlen = EVP_CCM_TLS_EXPLICIT_IV_LEN; 889 else 890 eivlen = 0; 891 } else 892 eivlen = 0; 893 894 /* lets setup the record stuff. */ 895 SSL3_RECORD_set_data(&wr, p + eivlen); /* make room for IV in case of CBC */ 896 SSL3_RECORD_set_length(&wr, len); 897 SSL3_RECORD_set_input(&wr, (unsigned char *)buf); 898 899 /* 900 * we now 'read' from wr.input, wr.length bytes into wr.data 901 */ 902 903 /* first we compress */ 904 if (s->compress != NULL) { 905 if (!ssl3_do_compress(s, &wr)) { 906 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_R_COMPRESSION_FAILURE); 907 return -1; 908 } 909 } else { 910 memcpy(SSL3_RECORD_get_data(&wr), SSL3_RECORD_get_input(&wr), 911 SSL3_RECORD_get_length(&wr)); 912 SSL3_RECORD_reset_input(&wr); 913 } 914 915 /* 916 * we should still have the output to wr.data and the input from 917 * wr.input. Length should be wr.length. wr.data still points in the 918 * wb->buf 919 */ 920 921 if (!SSL_WRITE_ETM(s) && mac_size != 0) { 922 if (!s->method->ssl3_enc->mac(s, &wr, 923 &(p[SSL3_RECORD_get_length(&wr) + eivlen]), 924 1)) { 925 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 926 return -1; 927 } 928 SSL3_RECORD_add_length(&wr, mac_size); 929 } 930 931 /* this is true regardless of mac size */ 932 SSL3_RECORD_set_data(&wr, p); 933 SSL3_RECORD_reset_input(&wr); 934 935 if (eivlen) 936 SSL3_RECORD_add_length(&wr, eivlen); 937 938 if (s->method->ssl3_enc->enc(s, &wr, 1, 1, NULL, mac_size) < 1) { 939 if (!ossl_statem_in_error(s)) { 940 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 941 } 942 return -1; 943 } 944 945 if (SSL_WRITE_ETM(s) && mac_size != 0) { 946 if (!s->method->ssl3_enc->mac(s, &wr, 947 &(p[SSL3_RECORD_get_length(&wr)]), 1)) { 948 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR); 949 return -1; 950 } 951 SSL3_RECORD_add_length(&wr, mac_size); 952 } 953 954 /* record length after mac and block padding */ 955 956 /* there's only one epoch between handshake and app data */ 957 958 s2n(s->rlayer.d->w_epoch, pseq); 959 960 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6); 961 pseq += 6; 962 s2n(SSL3_RECORD_get_length(&wr), pseq); 963 964 if (s->msg_callback) 965 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, 966 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg); 967 968 /* 969 * we should now have wr.data pointing to the encrypted data, which is 970 * wr->length long 971 */ 972 SSL3_RECORD_set_type(&wr, type); /* not needed but helps for debugging */ 973 SSL3_RECORD_add_length(&wr, DTLS1_RT_HEADER_LENGTH); 974 975 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0])); 976 977 if (create_empty_fragment) { 978 /* 979 * we are in a recursive call; just return the length, don't write 980 * out anything here 981 */ 982 *written = wr.length; 983 return 1; 984 } 985 986 /* now let's set up wb */ 987 SSL3_BUFFER_set_left(wb, prefix_len + SSL3_RECORD_get_length(&wr)); 988 SSL3_BUFFER_set_offset(wb, 0); 989 990 /* 991 * memorize arguments so that ssl3_write_pending can detect bad write 992 * retries later 993 */ 994 s->rlayer.wpend_tot = len; 995 s->rlayer.wpend_buf = buf; 996 s->rlayer.wpend_type = type; 997 s->rlayer.wpend_ret = len; 998 999 /* we now just need to write the buffer. Calls SSLfatal() as required. */ 1000 return ssl3_write_pending(s, type, buf, len, written); 1001} 1002 1003DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 1004 unsigned int *is_next_epoch) 1005{ 1006 1007 *is_next_epoch = 0; 1008 1009 /* In current epoch, accept HM, CCS, DATA, & ALERT */ 1010 if (rr->epoch == s->rlayer.d->r_epoch) 1011 return &s->rlayer.d->bitmap; 1012 1013 /* 1014 * We can only handle messages from the next epoch if we have already 1015 * processed all of the unprocessed records from the previous epoch 1016 */ 1017 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) 1018 && s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch) { 1019 *is_next_epoch = 1; 1020 return &s->rlayer.d->next_bitmap; 1021 } 1022 1023 return NULL; 1024} 1025 1026void dtls1_reset_seq_numbers(SSL *s, int rw) 1027{ 1028 unsigned char *seq; 1029 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence); 1030 1031 if (rw & SSL3_CC_READ) { 1032 seq = s->rlayer.read_sequence; 1033 s->rlayer.d->r_epoch++; 1034 memcpy(&s->rlayer.d->bitmap, &s->rlayer.d->next_bitmap, 1035 sizeof(s->rlayer.d->bitmap)); 1036 memset(&s->rlayer.d->next_bitmap, 0, sizeof(s->rlayer.d->next_bitmap)); 1037 1038 /* 1039 * We must not use any buffered messages received from the previous 1040 * epoch 1041 */ 1042 dtls1_clear_received_buffer(s); 1043 } else { 1044 seq = s->rlayer.write_sequence; 1045 memcpy(s->rlayer.d->last_write_sequence, seq, 1046 sizeof(s->rlayer.write_sequence)); 1047 s->rlayer.d->w_epoch++; 1048 } 1049 1050 memset(seq, 0, seq_bytes); 1051} 1052