1 /* $OpenBSD: ssl_pkt.c,v 1.58 2022/03/26 15:05:53 jsing Exp $ */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 /* ==================================================================== 59 * Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved. 60 * 61 * Redistribution and use in source and binary forms, with or without 62 * modification, are permitted provided that the following conditions 63 * are met: 64 * 65 * 1. Redistributions of source code must retain the above copyright 66 * notice, this list of conditions and the following disclaimer. 67 * 68 * 2. Redistributions in binary form must reproduce the above copyright 69 * notice, this list of conditions and the following disclaimer in 70 * the documentation and/or other materials provided with the 71 * distribution. 72 * 73 * 3. All advertising materials mentioning features or use of this 74 * software must display the following acknowledgment: 75 * "This product includes software developed by the OpenSSL Project 76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 77 * 78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 79 * endorse or promote products derived from this software without 80 * prior written permission. For written permission, please contact 81 * openssl-core@openssl.org. 82 * 83 * 5. Products derived from this software may not be called "OpenSSL" 84 * nor may "OpenSSL" appear in their names without prior written 85 * permission of the OpenSSL Project. 86 * 87 * 6. Redistributions of any form whatsoever must retain the following 88 * acknowledgment: 89 * "This product includes software developed by the OpenSSL Project 90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" 91 * 92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 103 * OF THE POSSIBILITY OF SUCH DAMAGE. 104 * ==================================================================== 105 * 106 * This product includes cryptographic software written by Eric Young 107 * (eay@cryptsoft.com). This product includes software written by Tim 108 * Hudson (tjh@cryptsoft.com). 109 * 110 */ 111 112 #include <errno.h> 113 #include <stdio.h> 114 115 #include <openssl/buffer.h> 116 #include <openssl/evp.h> 117 118 #include "bytestring.h" 119 #include "dtls_locl.h" 120 #include "ssl_locl.h" 121 122 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, 123 unsigned int len); 124 static int ssl3_get_record(SSL *s); 125 126 /* 127 * Force a WANT_READ return for certain error conditions where 128 * we don't want to spin internally. 129 */ 130 void 131 ssl_force_want_read(SSL *s) 132 { 133 BIO *bio; 134 135 bio = SSL_get_rbio(s); 136 BIO_clear_retry_flags(bio); 137 BIO_set_retry_read(bio); 138 139 s->internal->rwstate = SSL_READING; 140 } 141 142 /* 143 * If extend == 0, obtain new n-byte packet; if extend == 1, increase 144 * packet by another n bytes. 145 * The packet will be in the sub-array of s->s3->rbuf.buf specified 146 * by s->internal->packet and s->internal->packet_length. 147 * (If s->internal->read_ahead is set, 'max' bytes may be stored in rbuf 148 * [plus s->internal->packet_length bytes if extend == 1].) 149 */ 150 static int 151 ssl3_read_n(SSL *s, int n, int max, int extend) 152 { 153 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf); 154 int i, len, left; 155 size_t align; 156 unsigned char *pkt; 157 158 if (n <= 0) 159 return n; 160 161 if (rb->buf == NULL) 162 if (!ssl3_setup_read_buffer(s)) 163 return -1; 164 165 left = rb->left; 166 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH; 167 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 168 169 if (!extend) { 170 /* start with empty packet ... */ 171 if (left == 0) 172 rb->offset = align; 173 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { 174 /* check if next packet length is large 175 * enough to justify payload alignment... */ 176 pkt = rb->buf + rb->offset; 177 if (pkt[0] == SSL3_RT_APPLICATION_DATA && 178 (pkt[3]<<8|pkt[4]) >= 128) { 179 /* Note that even if packet is corrupted 180 * and its length field is insane, we can 181 * only be led to wrong decision about 182 * whether memmove will occur or not. 183 * Header values has no effect on memmove 184 * arguments and therefore no buffer 185 * overrun can be triggered. */ 186 memmove(rb->buf + align, pkt, left); 187 rb->offset = align; 188 } 189 } 190 s->internal->packet = rb->buf + rb->offset; 191 s->internal->packet_length = 0; 192 /* ... now we can act as if 'extend' was set */ 193 } 194 195 /* For DTLS/UDP reads should not span multiple packets 196 * because the read operation returns the whole packet 197 * at once (as long as it fits into the buffer). */ 198 if (SSL_is_dtls(s)) { 199 if (left > 0 && n > left) 200 n = left; 201 } 202 203 /* if there is enough in the buffer from a previous read, take some */ 204 if (left >= n) { 205 s->internal->packet_length += n; 206 rb->left = left - n; 207 rb->offset += n; 208 return (n); 209 } 210 211 /* else we need to read more data */ 212 213 len = s->internal->packet_length; 214 pkt = rb->buf + align; 215 /* Move any available bytes to front of buffer: 216 * 'len' bytes already pointed to by 'packet', 217 * 'left' extra ones at the end */ 218 if (s->internal->packet != pkt) { 219 /* len > 0 */ 220 memmove(pkt, s->internal->packet, len + left); 221 s->internal->packet = pkt; 222 rb->offset = len + align; 223 } 224 225 if (n > (int)(rb->len - rb->offset)) { 226 /* does not happen */ 227 SSLerror(s, ERR_R_INTERNAL_ERROR); 228 return -1; 229 } 230 231 if (s->internal->read_ahead || SSL_is_dtls(s)) { 232 if (max < n) 233 max = n; 234 if (max > (int)(rb->len - rb->offset)) 235 max = rb->len - rb->offset; 236 } else { 237 /* ignore max parameter */ 238 max = n; 239 } 240 241 while (left < n) { 242 /* Now we have len+left bytes at the front of s->s3->rbuf.buf 243 * and need to read in more until we have len+n (up to 244 * len+max if possible) */ 245 246 errno = 0; 247 if (s->rbio != NULL) { 248 s->internal->rwstate = SSL_READING; 249 i = BIO_read(s->rbio, pkt + len + left, max - left); 250 } else { 251 SSLerror(s, SSL_R_READ_BIO_NOT_SET); 252 i = -1; 253 } 254 255 if (i <= 0) { 256 rb->left = left; 257 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 258 !SSL_is_dtls(s)) { 259 if (len + left == 0) 260 ssl3_release_read_buffer(s); 261 } 262 return (i); 263 } 264 left += i; 265 266 /* 267 * reads should *never* span multiple packets for DTLS because 268 * the underlying transport protocol is message oriented as 269 * opposed to byte oriented as in the TLS case. 270 */ 271 if (SSL_is_dtls(s)) { 272 if (n > left) 273 n = left; /* makes the while condition false */ 274 } 275 } 276 277 /* done reading, now the book-keeping */ 278 rb->offset += n; 279 rb->left = left - n; 280 s->internal->packet_length += n; 281 s->internal->rwstate = SSL_NOTHING; 282 283 return (n); 284 } 285 286 int 287 ssl3_packet_read(SSL *s, int plen) 288 { 289 int n; 290 291 n = ssl3_read_n(s, plen, s->s3->rbuf.len, 0); 292 if (n <= 0) 293 return n; 294 if (s->internal->packet_length < plen) 295 return s->internal->packet_length; 296 297 return plen; 298 } 299 300 int 301 ssl3_packet_extend(SSL *s, int plen) 302 { 303 int rlen, n; 304 305 if (s->internal->packet_length >= plen) 306 return plen; 307 rlen = plen - s->internal->packet_length; 308 309 n = ssl3_read_n(s, rlen, rlen, 1); 310 if (n <= 0) 311 return n; 312 if (s->internal->packet_length < plen) 313 return s->internal->packet_length; 314 315 return plen; 316 } 317 318 /* Call this to get a new input record. 319 * It will return <= 0 if more data is needed, normally due to an error 320 * or non-blocking IO. 321 * When it finishes, one packet has been decoded and can be found in 322 * ssl->s3->internal->rrec.type - is the type of record 323 * ssl->s3->internal->rrec.data, - data 324 * ssl->s3->internal->rrec.length, - number of bytes 325 */ 326 /* used only by ssl3_read_bytes */ 327 static int 328 ssl3_get_record(SSL *s) 329 { 330 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf); 331 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); 332 uint8_t alert_desc; 333 uint8_t *out; 334 size_t out_len; 335 int al, n; 336 int ret = -1; 337 338 again: 339 /* check if we have the header */ 340 if ((s->internal->rstate != SSL_ST_READ_BODY) || 341 (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) { 342 CBS header; 343 uint16_t len, ssl_version; 344 uint8_t type; 345 346 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH); 347 if (n <= 0) 348 return (n); 349 350 s->internal->mac_packet = 1; 351 s->internal->rstate = SSL_ST_READ_BODY; 352 353 if (s->server && s->internal->first_packet) { 354 if ((ret = ssl_server_legacy_first_packet(s)) != 1) 355 return (ret); 356 ret = -1; 357 } 358 359 CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH); 360 361 /* Pull apart the header into the SSL3_RECORD_INTERNAL */ 362 if (!CBS_get_u8(&header, &type) || 363 !CBS_get_u16(&header, &ssl_version) || 364 !CBS_get_u16(&header, &len)) { 365 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 366 goto err; 367 } 368 369 rr->type = type; 370 rr->length = len; 371 372 /* Lets check version */ 373 if (!s->internal->first_packet && ssl_version != s->version) { 374 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && 375 !tls12_record_layer_write_protected(s->internal->rl)) { 376 /* Send back error using their minor version number :-) */ 377 s->version = ssl_version; 378 } 379 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 380 al = SSL_AD_PROTOCOL_VERSION; 381 goto fatal_err; 382 } 383 384 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) { 385 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 386 goto err; 387 } 388 389 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) { 390 al = SSL_AD_RECORD_OVERFLOW; 391 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG); 392 goto fatal_err; 393 } 394 } 395 396 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length); 397 if (n <= 0) 398 return (n); 399 if (n != SSL3_RT_HEADER_LENGTH + rr->length) 400 return (n); 401 402 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 403 404 /* 405 * A full record has now been read from the wire, which now needs 406 * to be processed. 407 */ 408 tls12_record_layer_set_version(s->internal->rl, s->version); 409 410 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, 411 s->internal->packet_length, &out, &out_len)) { 412 tls12_record_layer_alert(s->internal->rl, &alert_desc); 413 414 if (alert_desc == 0) 415 goto err; 416 417 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 418 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 419 else if (alert_desc == SSL_AD_BAD_RECORD_MAC) 420 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 421 422 al = alert_desc; 423 goto fatal_err; 424 } 425 426 rr->data = out; 427 rr->length = out_len; 428 rr->off = 0; 429 430 /* we have pulled in a full packet so zero things */ 431 s->internal->packet_length = 0; 432 433 if (rr->length == 0) { 434 /* 435 * Zero-length fragments are only permitted for application 436 * data, as per RFC 5246 section 6.2.1. 437 */ 438 if (rr->type != SSL3_RT_APPLICATION_DATA) { 439 SSLerror(s, SSL_R_BAD_LENGTH); 440 al = SSL_AD_UNEXPECTED_MESSAGE; 441 goto fatal_err; 442 } 443 444 /* 445 * CBC countermeasures for known IV weaknesses can legitimately 446 * insert a single empty record, so we allow ourselves to read 447 * once past a single empty record without forcing want_read. 448 */ 449 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 450 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 451 return -1; 452 } 453 if (s->internal->empty_record_count > 1) { 454 ssl_force_want_read(s); 455 return -1; 456 } 457 goto again; 458 } 459 460 s->internal->empty_record_count = 0; 461 462 return (1); 463 464 fatal_err: 465 ssl3_send_alert(s, SSL3_AL_FATAL, al); 466 err: 467 return (ret); 468 } 469 470 /* Call this to write data in records of type 'type' 471 * It will return <= 0 if not all data has been sent or non-blocking IO. 472 */ 473 int 474 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 475 { 476 const unsigned char *buf = buf_; 477 unsigned int tot, n, nw; 478 int i; 479 480 if (len < 0) { 481 SSLerror(s, ERR_R_INTERNAL_ERROR); 482 return -1; 483 } 484 485 s->internal->rwstate = SSL_NOTHING; 486 tot = s->s3->wnum; 487 s->s3->wnum = 0; 488 489 if (SSL_in_init(s) && !s->internal->in_handshake) { 490 i = s->internal->handshake_func(s); 491 if (i < 0) 492 return (i); 493 if (i == 0) { 494 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 495 return -1; 496 } 497 } 498 499 if (len < tot) 500 len = tot; 501 n = (len - tot); 502 for (;;) { 503 if (n > s->max_send_fragment) 504 nw = s->max_send_fragment; 505 else 506 nw = n; 507 508 i = do_ssl3_write(s, type, &(buf[tot]), nw); 509 if (i <= 0) { 510 s->s3->wnum = tot; 511 return i; 512 } 513 514 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 515 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 516 /* 517 * Next chunk of data should get another prepended 518 * empty fragment in ciphersuites with known-IV 519 * weakness. 520 */ 521 s->s3->empty_fragment_done = 0; 522 523 return tot + i; 524 } 525 526 n -= i; 527 tot += i; 528 } 529 } 530 531 static int 532 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 533 { 534 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); 535 SSL_SESSION *sess = s->session; 536 int need_empty_fragment = 0; 537 size_t align, out_len; 538 uint16_t version; 539 CBB cbb; 540 int ret; 541 542 memset(&cbb, 0, sizeof(cbb)); 543 544 if (wb->buf == NULL) 545 if (!ssl3_setup_write_buffer(s)) 546 return -1; 547 548 /* 549 * First check if there is a SSL3_BUFFER_INTERNAL still being written 550 * out. This will happen with non blocking IO. 551 */ 552 if (wb->left != 0) 553 return (ssl3_write_pending(s, type, buf, len)); 554 555 /* If we have an alert to send, let's send it. */ 556 if (s->s3->alert_dispatch) { 557 if ((ret = ssl3_dispatch_alert(s)) <= 0) 558 return (ret); 559 /* If it went, fall through and send more stuff. */ 560 561 /* We may have released our buffer, if so get it again. */ 562 if (wb->buf == NULL) 563 if (!ssl3_setup_write_buffer(s)) 564 return -1; 565 } 566 567 if (len == 0) 568 return 0; 569 570 /* 571 * Some servers hang if initial client hello is larger than 256 572 * bytes and record version number > TLS 1.0. 573 */ 574 version = s->version; 575 if (s->s3->hs.state == SSL3_ST_CW_CLNT_HELLO_B && 576 !s->internal->renegotiate && 577 s->s3->hs.our_max_tls_version > TLS1_VERSION) 578 version = TLS1_VERSION; 579 580 /* 581 * Countermeasure against known-IV weakness in CBC ciphersuites 582 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this 583 * is unnecessary for AEAD. 584 */ 585 if (sess != NULL && tls12_record_layer_write_protected(s->internal->rl)) { 586 if (s->s3->need_empty_fragments && 587 !s->s3->empty_fragment_done && 588 type == SSL3_RT_APPLICATION_DATA) 589 need_empty_fragment = 1; 590 } 591 592 /* 593 * An extra fragment would be a couple of cipher blocks, which would 594 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 595 * payload, then we can just simply pretend we have two headers. 596 */ 597 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 598 if (need_empty_fragment) 599 align += SSL3_RT_HEADER_LENGTH; 600 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 601 wb->offset = align; 602 603 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) 604 goto err; 605 606 tls12_record_layer_set_version(s->internal->rl, version); 607 608 if (need_empty_fragment) { 609 if (!tls12_record_layer_seal_record(s->internal->rl, type, 610 buf, 0, &cbb)) 611 goto err; 612 s->s3->empty_fragment_done = 1; 613 } 614 615 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 616 goto err; 617 618 if (!CBB_finish(&cbb, NULL, &out_len)) 619 goto err; 620 621 wb->left = out_len; 622 623 /* 624 * Memorize arguments so that ssl3_write_pending can detect 625 * bad write retries later. 626 */ 627 s->s3->wpend_tot = len; 628 s->s3->wpend_buf = buf; 629 s->s3->wpend_type = type; 630 s->s3->wpend_ret = len; 631 632 /* We now just need to write the buffer. */ 633 return ssl3_write_pending(s, type, buf, len); 634 635 err: 636 CBB_cleanup(&cbb); 637 638 return -1; 639 } 640 641 /* if s->s3->wbuf.left != 0, we need to call this */ 642 int 643 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 644 { 645 int i; 646 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); 647 648 /* XXXX */ 649 if ((s->s3->wpend_tot > (int)len) || ((s->s3->wpend_buf != buf) && 650 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 651 (s->s3->wpend_type != type)) { 652 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 653 return (-1); 654 } 655 656 for (;;) { 657 errno = 0; 658 if (s->wbio != NULL) { 659 s->internal->rwstate = SSL_WRITING; 660 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), 661 (unsigned int)wb->left); 662 } else { 663 SSLerror(s, SSL_R_BIO_NOT_SET); 664 i = -1; 665 } 666 if (i == wb->left) { 667 wb->left = 0; 668 wb->offset += i; 669 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 670 !SSL_is_dtls(s)) 671 ssl3_release_write_buffer(s); 672 s->internal->rwstate = SSL_NOTHING; 673 return (s->s3->wpend_ret); 674 } else if (i <= 0) { 675 /* 676 * For DTLS, just drop it. That's kind of the 677 * whole point in using a datagram service. 678 */ 679 if (SSL_is_dtls(s)) 680 wb->left = 0; 681 return (i); 682 } 683 wb->offset += i; 684 wb->left -= i; 685 } 686 } 687 688 int 689 ssl3_read_alert(SSL *s) 690 { 691 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec; 692 uint8_t alert_level, alert_descr; 693 694 /* 695 * TLSv1.2 permits an alert to be fragmented across multiple records or 696 * for multiple alerts to be be coalesced into a single alert record. 697 * In the case of DTLS, there is no way to reassemble an alert 698 * fragmented across multiple records, hence a full alert must be 699 * available in the record. 700 */ 701 while (rr->length > 0 && 702 s->s3->alert_fragment_len < sizeof(s->s3->alert_fragment)) { 703 s->s3->alert_fragment[s->s3->alert_fragment_len++] = 704 rr->data[rr->off++]; 705 rr->length--; 706 } 707 if (s->s3->alert_fragment_len < sizeof(s->s3->alert_fragment)) { 708 if (SSL_is_dtls(s)) { 709 SSLerror(s, SSL_R_BAD_LENGTH); 710 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 711 return -1; 712 } 713 return 1; 714 } 715 716 ssl_msg_callback(s, 0, SSL3_RT_ALERT, s->s3->alert_fragment, 2); 717 718 alert_level = s->s3->alert_fragment[0]; 719 alert_descr = s->s3->alert_fragment[1]; 720 s->s3->alert_fragment_len = 0; 721 722 ssl_info_callback(s, SSL_CB_READ_ALERT, 723 (alert_level << 8) | alert_descr); 724 725 if (alert_level == SSL3_AL_WARNING) { 726 s->s3->warn_alert = alert_descr; 727 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 728 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 729 return 0; 730 } 731 /* We requested renegotiation and the peer rejected it. */ 732 if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 733 SSLerror(s, SSL_R_NO_RENEGOTIATION); 734 ssl3_send_alert(s, SSL3_AL_FATAL, 735 SSL_AD_HANDSHAKE_FAILURE); 736 return -1; 737 } 738 } else if (alert_level == SSL3_AL_FATAL) { 739 s->internal->rwstate = SSL_NOTHING; 740 s->s3->fatal_alert = alert_descr; 741 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 742 ERR_asprintf_error_data("SSL alert number %d", alert_descr); 743 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 744 SSL_CTX_remove_session(s->ctx, s->session); 745 return 0; 746 } else { 747 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 748 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); 749 return -1; 750 } 751 752 return 1; 753 } 754 755 int 756 ssl3_read_change_cipher_spec(SSL *s) 757 { 758 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec; 759 760 /* 761 * 'Change Cipher Spec' is just a single byte, so we know exactly what 762 * the record payload has to look like. 763 */ 764 if (rr->length != 1 || rr->off != 0) { 765 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 766 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 767 return -1; 768 } 769 if (rr->data[0] != SSL3_MT_CCS) { 770 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 771 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); 772 return -1; 773 } 774 775 /* XDTLS: check that epoch is consistent */ 776 777 ssl_msg_callback(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1); 778 779 /* Check that we have a cipher to change to. */ 780 if (s->s3->hs.cipher == NULL) { 781 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 782 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 783 return -1; 784 } 785 786 /* Check that we should be receiving a Change Cipher Spec. */ 787 if (SSL_is_dtls(s)) { 788 if (!s->d1->change_cipher_spec_ok) { 789 /* 790 * We can't process a CCS now, because previous 791 * handshake messages are still missing, so just 792 * drop it. 793 */ 794 rr->length = 0; 795 return 1; 796 } 797 s->d1->change_cipher_spec_ok = 0; 798 } else { 799 if ((s->s3->flags & SSL3_FLAGS_CCS_OK) == 0) { 800 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 801 ssl3_send_alert(s, SSL3_AL_FATAL, 802 SSL_AD_UNEXPECTED_MESSAGE); 803 return -1; 804 } 805 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 806 } 807 808 rr->length = 0; 809 810 s->s3->change_cipher_spec = 1; 811 if (!ssl3_do_change_cipher_spec(s)) 812 return -1; 813 814 return 1; 815 } 816 817 static int 818 ssl3_read_handshake_unexpected(SSL *s) 819 { 820 SSL3_RECORD_INTERNAL *rr = &s->s3->rrec; 821 uint32_t hs_msg_length; 822 uint8_t hs_msg_type; 823 CBS cbs; 824 int ret; 825 826 /* 827 * We need four bytes of handshake data so we have a handshake message 828 * header - this may be in the same record or fragmented across multiple 829 * records. 830 */ 831 while (rr->length > 0 && 832 s->s3->handshake_fragment_len < sizeof(s->s3->handshake_fragment)) { 833 s->s3->handshake_fragment[s->s3->handshake_fragment_len++] = 834 rr->data[rr->off++]; 835 rr->length--; 836 } 837 838 if (s->s3->handshake_fragment_len < sizeof(s->s3->handshake_fragment)) 839 return 1; 840 841 if (s->internal->in_handshake) { 842 SSLerror(s, ERR_R_INTERNAL_ERROR); 843 return -1; 844 } 845 846 /* 847 * This code currently deals with HelloRequest and ClientHello messages - 848 * anything else is pushed to the handshake_func. Almost all of this 849 * belongs in the client/server handshake code. 850 */ 851 852 /* Parse handshake message header. */ 853 CBS_init(&cbs, s->s3->handshake_fragment, s->s3->handshake_fragment_len); 854 if (!CBS_get_u8(&cbs, &hs_msg_type)) 855 return -1; 856 if (!CBS_get_u24(&cbs, &hs_msg_length)) 857 return -1; 858 859 if (hs_msg_type == SSL3_MT_HELLO_REQUEST) { 860 /* 861 * Incoming HelloRequest messages should only be received by a 862 * client. A server may send these at any time - a client should 863 * ignore the message if received in the middle of a handshake. 864 * See RFC 5246 sections 7.4 and 7.4.1.1. 865 */ 866 if (s->server) { 867 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 868 ssl3_send_alert(s, SSL3_AL_FATAL, 869 SSL_AD_UNEXPECTED_MESSAGE); 870 return -1; 871 } 872 873 if (hs_msg_length != 0) { 874 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 875 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 876 return -1; 877 } 878 879 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, 880 s->s3->handshake_fragment, s->s3->handshake_fragment_len); 881 882 s->s3->handshake_fragment_len = 0; 883 884 /* 885 * It should be impossible to hit this, but keep the safety 886 * harness for now... 887 */ 888 if (s->session == NULL || s->session->cipher == NULL) 889 return 1; 890 891 /* 892 * Ignore this message if we're currently handshaking, 893 * renegotiation is already pending or renegotiation is disabled 894 * via flags. 895 */ 896 if (!SSL_is_init_finished(s) || s->s3->renegotiate || 897 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) 898 return 1; 899 900 if (!ssl3_renegotiate(s)) 901 return 1; 902 if (!ssl3_renegotiate_check(s)) 903 return 1; 904 905 } else if (hs_msg_type == SSL3_MT_CLIENT_HELLO) { 906 /* 907 * Incoming ClientHello messages should only be received by a 908 * server. A client may send these in response to server 909 * initiated renegotiation (HelloRequest) or in order to 910 * initiate renegotiation by the client. See RFC 5246 section 911 * 7.4.1.2. 912 */ 913 if (!s->server) { 914 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 915 ssl3_send_alert(s, SSL3_AL_FATAL, 916 SSL_AD_UNEXPECTED_MESSAGE); 917 return -1; 918 } 919 920 /* 921 * A client should not be sending a ClientHello unless we're not 922 * currently handshaking. 923 */ 924 if (!SSL_is_init_finished(s)) { 925 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 926 ssl3_send_alert(s, SSL3_AL_FATAL, 927 SSL_AD_UNEXPECTED_MESSAGE); 928 return -1; 929 } 930 931 if ((s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) { 932 ssl3_send_alert(s, SSL3_AL_FATAL, 933 SSL_AD_NO_RENEGOTIATION); 934 return -1; 935 } 936 937 if (s->session == NULL || s->session->cipher == NULL) { 938 SSLerror(s, ERR_R_INTERNAL_ERROR); 939 return -1; 940 } 941 942 /* Client requested renegotiation but it is not permitted. */ 943 if (!s->s3->send_connection_binding || 944 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) { 945 ssl3_send_alert(s, SSL3_AL_WARNING, 946 SSL_AD_NO_RENEGOTIATION); 947 return 1; 948 } 949 950 s->s3->hs.state = SSL_ST_ACCEPT; 951 s->internal->renegotiate = 1; 952 s->internal->new_session = 1; 953 954 } else { 955 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 956 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 957 return -1; 958 } 959 960 if ((ret = s->internal->handshake_func(s)) < 0) 961 return ret; 962 if (ret == 0) { 963 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 964 return -1; 965 } 966 967 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 968 if (s->s3->rbuf.left == 0) { 969 ssl_force_want_read(s); 970 return -1; 971 } 972 } 973 974 /* 975 * We either finished a handshake or ignored the request, now try again 976 * to obtain the (application) data we were asked for. 977 */ 978 return 1; 979 } 980 981 /* Return up to 'len' payload bytes received in 'type' records. 982 * 'type' is one of the following: 983 * 984 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 985 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 986 * - 0 (during a shutdown, no data has to be returned) 987 * 988 * If we don't have stored data to work from, read a SSL/TLS record first 989 * (possibly multiple records if we still don't have anything to return). 990 * 991 * This function must handle any surprises the peer may have for us, such as 992 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 993 * a surprise, but handled as if it were), or renegotiation requests. 994 * Also if record payloads contain fragments too small to process, we store 995 * them until there is enough for the respective protocol (the record protocol 996 * may use arbitrary fragmentation and even interleaving): 997 * Change cipher spec protocol 998 * just 1 byte needed, no need for keeping anything stored 999 * Alert protocol 1000 * 2 bytes needed (AlertLevel, AlertDescription) 1001 * Handshake protocol 1002 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 1003 * to detect unexpected Client Hello and Hello Request messages 1004 * here, anything else is handled by higher layers 1005 * Application data protocol 1006 * none of our business 1007 */ 1008 int 1009 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 1010 { 1011 SSL3_RECORD_INTERNAL *rr; 1012 int rrcount = 0; 1013 unsigned int n; 1014 int ret; 1015 1016 if (s->s3->rbuf.buf == NULL) { 1017 if (!ssl3_setup_read_buffer(s)) 1018 return -1; 1019 } 1020 1021 if (len < 0) { 1022 SSLerror(s, ERR_R_INTERNAL_ERROR); 1023 return -1; 1024 } 1025 1026 if (type != 0 && type != SSL3_RT_APPLICATION_DATA && 1027 type != SSL3_RT_HANDSHAKE) { 1028 SSLerror(s, ERR_R_INTERNAL_ERROR); 1029 return -1; 1030 } 1031 if (peek && type != SSL3_RT_APPLICATION_DATA) { 1032 SSLerror(s, ERR_R_INTERNAL_ERROR); 1033 return -1; 1034 } 1035 1036 if (type == SSL3_RT_HANDSHAKE && s->s3->handshake_fragment_len > 0) { 1037 /* Partially satisfy request from fragment storage. */ 1038 unsigned char *src = s->s3->handshake_fragment; 1039 unsigned char *dst = buf; 1040 unsigned int k; 1041 1042 /* peek == 0 */ 1043 n = 0; 1044 while (len > 0 && s->s3->handshake_fragment_len > 0) { 1045 *dst++ = *src++; 1046 len--; 1047 s->s3->handshake_fragment_len--; 1048 n++; 1049 } 1050 /* move any remaining fragment bytes: */ 1051 for (k = 0; k < s->s3->handshake_fragment_len; k++) 1052 s->s3->handshake_fragment[k] = *src++; 1053 return n; 1054 } 1055 1056 if (SSL_in_init(s) && !s->internal->in_handshake) { 1057 if ((ret = s->internal->handshake_func(s)) < 0) 1058 return ret; 1059 if (ret == 0) { 1060 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1061 return -1; 1062 } 1063 } 1064 1065 start: 1066 /* 1067 * Do not process more than three consecutive records, otherwise the 1068 * peer can cause us to loop indefinitely. Instead, return with an 1069 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 1070 * processing. In the future, the total number of non-handshake and 1071 * non-application data records per connection should probably also be 1072 * limited... 1073 */ 1074 if (rrcount++ >= 3) { 1075 ssl_force_want_read(s); 1076 return -1; 1077 } 1078 1079 s->internal->rwstate = SSL_NOTHING; 1080 1081 rr = &s->s3->rrec; 1082 1083 if (rr->length == 0 || s->internal->rstate == SSL_ST_READ_BODY) { 1084 if ((ret = ssl3_get_record(s)) <= 0) 1085 return ret; 1086 } 1087 1088 /* We now have a packet which can be read and processed. */ 1089 1090 if (s->s3->change_cipher_spec && rr->type != SSL3_RT_HANDSHAKE) { 1091 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 1092 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 1093 return -1; 1094 } 1095 1096 /* 1097 * If the other end has shut down, throw anything we read away (even in 1098 * 'peek' mode). 1099 */ 1100 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 1101 s->internal->rwstate = SSL_NOTHING; 1102 rr->length = 0; 1103 return 0; 1104 } 1105 1106 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 1107 if (type == rr->type) { 1108 /* 1109 * Make sure that we are not getting application data when we 1110 * are doing a handshake for the first time. 1111 */ 1112 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 1113 !tls12_record_layer_read_protected(s->internal->rl)) { 1114 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 1115 ssl3_send_alert(s, SSL3_AL_FATAL, 1116 SSL_AD_UNEXPECTED_MESSAGE); 1117 return -1; 1118 } 1119 1120 if (len <= 0) 1121 return len; 1122 1123 if ((unsigned int)len > rr->length) 1124 n = rr->length; 1125 else 1126 n = (unsigned int)len; 1127 1128 memcpy(buf, &rr->data[rr->off], n); 1129 if (!peek) { 1130 memset(&rr->data[rr->off], 0, n); 1131 rr->length -= n; 1132 rr->off += n; 1133 if (rr->length == 0) { 1134 s->internal->rstate = SSL_ST_READ_HEADER; 1135 rr->off = 0; 1136 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 1137 s->s3->rbuf.left == 0) 1138 ssl3_release_read_buffer(s); 1139 } 1140 } 1141 1142 return n; 1143 } 1144 1145 /* 1146 * If we get here, then type != rr->type; if we have a handshake 1147 * message, then it was unexpected (Hello Request or Client Hello). 1148 */ 1149 1150 if (rr->type == SSL3_RT_ALERT) { 1151 if ((ret = ssl3_read_alert(s)) <= 0) 1152 return ret; 1153 goto start; 1154 } 1155 1156 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 1157 s->internal->rwstate = SSL_NOTHING; 1158 rr->length = 0; 1159 return 0; 1160 } 1161 1162 if (rr->type == SSL3_RT_APPLICATION_DATA) { 1163 /* 1164 * At this point, we were expecting handshake data, but have 1165 * application data. If the library was running inside 1166 * ssl3_read() (i.e. in_read_app_data is set) and it makes 1167 * sense to read application data at this point (session 1168 * renegotiation not yet started), we will indulge it. 1169 */ 1170 if (s->s3->in_read_app_data != 0 && 1171 s->s3->total_renegotiations != 0 && 1172 (((s->s3->hs.state & SSL_ST_CONNECT) && 1173 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1174 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 1175 (s->s3->hs.state & SSL_ST_ACCEPT) && 1176 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1177 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1178 s->s3->in_read_app_data = 2; 1179 return -1; 1180 } else { 1181 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1182 ssl3_send_alert(s, SSL3_AL_FATAL, 1183 SSL_AD_UNEXPECTED_MESSAGE); 1184 return -1; 1185 } 1186 } 1187 1188 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1189 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0) 1190 return ret; 1191 goto start; 1192 } 1193 1194 if (rr->type == SSL3_RT_HANDSHAKE) { 1195 if ((ret = ssl3_read_handshake_unexpected(s)) <= 0) 1196 return ret; 1197 goto start; 1198 } 1199 1200 /* 1201 * Unknown record type - TLSv1.2 sends an unexpected message alert while 1202 * earlier versions silently ignore the record. 1203 */ 1204 if (ssl_effective_tls_version(s) <= TLS1_1_VERSION) { 1205 rr->length = 0; 1206 goto start; 1207 } 1208 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1209 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 1210 return -1; 1211 } 1212 1213 int 1214 ssl3_do_change_cipher_spec(SSL *s) 1215 { 1216 if (s->s3->hs.tls12.key_block == NULL) { 1217 if (s->session == NULL || s->session->master_key_length == 0) { 1218 /* might happen if dtls1_read_bytes() calls this */ 1219 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1220 return (0); 1221 } 1222 1223 s->session->cipher = s->s3->hs.cipher; 1224 if (!tls1_setup_key_block(s)) 1225 return (0); 1226 } 1227 1228 if (!tls1_change_read_cipher_state(s)) 1229 return (0); 1230 1231 /* 1232 * We have to record the message digest at this point so we can get it 1233 * before we read the finished message. 1234 */ 1235 if (!tls12_derive_peer_finished(s)) 1236 return (0); 1237 1238 return (1); 1239 } 1240 1241 static int 1242 ssl3_write_alert(SSL *s) 1243 { 1244 if (SSL_is_dtls(s)) 1245 return do_dtls1_write(s, SSL3_RT_ALERT, s->s3->send_alert, 1246 sizeof(s->s3->send_alert)); 1247 1248 return do_ssl3_write(s, SSL3_RT_ALERT, s->s3->send_alert, 1249 sizeof(s->s3->send_alert)); 1250 } 1251 1252 int 1253 ssl3_send_alert(SSL *s, int level, int desc) 1254 { 1255 /* If alert is fatal, remove session from cache. */ 1256 if (level == SSL3_AL_FATAL) 1257 SSL_CTX_remove_session(s->ctx, s->session); 1258 1259 s->s3->alert_dispatch = 1; 1260 s->s3->send_alert[0] = level; 1261 s->s3->send_alert[1] = desc; 1262 1263 /* 1264 * If data is still being written out, the alert will be dispatched at 1265 * some point in the future. 1266 */ 1267 if (s->s3->wbuf.left != 0) 1268 return -1; 1269 1270 return ssl3_dispatch_alert(s); 1271 } 1272 1273 int 1274 ssl3_dispatch_alert(SSL *s) 1275 { 1276 int ret; 1277 1278 s->s3->alert_dispatch = 0; 1279 if ((ret = ssl3_write_alert(s)) <= 0) { 1280 s->s3->alert_dispatch = 1; 1281 return ret; 1282 } 1283 1284 /* 1285 * Alert sent to BIO. If it is important, flush it now. 1286 * If the message does not get sent due to non-blocking IO, 1287 * we will not worry too much. 1288 */ 1289 if (s->s3->send_alert[0] == SSL3_AL_FATAL) 1290 (void)BIO_flush(s->wbio); 1291 1292 ssl_msg_callback(s, 1, SSL3_RT_ALERT, s->s3->send_alert, 2); 1293 1294 ssl_info_callback(s, SSL_CB_WRITE_ALERT, 1295 (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]); 1296 1297 return ret; 1298 } 1299