1 /* $OpenBSD: ssl_pkt.c,v 1.50 2021/08/30 19:25:43 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 static 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 s->internal->rwstate = SSL_READING; 139 } 140 141 /* 142 * If extend == 0, obtain new n-byte packet; if extend == 1, increase 143 * packet by another n bytes. 144 * The packet will be in the sub-array of S3I(s)->rbuf.buf specified 145 * by s->internal->packet and s->internal->packet_length. 146 * (If s->internal->read_ahead is set, 'max' bytes may be stored in rbuf 147 * [plus s->internal->packet_length bytes if extend == 1].) 148 */ 149 static int 150 ssl3_read_n(SSL *s, int n, int max, int extend) 151 { 152 SSL3_BUFFER_INTERNAL *rb = &(S3I(s)->rbuf); 153 int i, len, left; 154 size_t align; 155 unsigned char *pkt; 156 157 if (n <= 0) 158 return n; 159 160 if (rb->buf == NULL) 161 if (!ssl3_setup_read_buffer(s)) 162 return -1; 163 164 left = rb->left; 165 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH; 166 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 167 168 if (!extend) { 169 /* start with empty packet ... */ 170 if (left == 0) 171 rb->offset = align; 172 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { 173 /* check if next packet length is large 174 * enough to justify payload alignment... */ 175 pkt = rb->buf + rb->offset; 176 if (pkt[0] == SSL3_RT_APPLICATION_DATA && 177 (pkt[3]<<8|pkt[4]) >= 128) { 178 /* Note that even if packet is corrupted 179 * and its length field is insane, we can 180 * only be led to wrong decision about 181 * whether memmove will occur or not. 182 * Header values has no effect on memmove 183 * arguments and therefore no buffer 184 * overrun can be triggered. */ 185 memmove(rb->buf + align, pkt, left); 186 rb->offset = align; 187 } 188 } 189 s->internal->packet = rb->buf + rb->offset; 190 s->internal->packet_length = 0; 191 /* ... now we can act as if 'extend' was set */ 192 } 193 194 /* For DTLS/UDP reads should not span multiple packets 195 * because the read operation returns the whole packet 196 * at once (as long as it fits into the buffer). */ 197 if (SSL_is_dtls(s)) { 198 if (left > 0 && n > left) 199 n = left; 200 } 201 202 /* if there is enough in the buffer from a previous read, take some */ 203 if (left >= n) { 204 s->internal->packet_length += n; 205 rb->left = left - n; 206 rb->offset += n; 207 return (n); 208 } 209 210 /* else we need to read more data */ 211 212 len = s->internal->packet_length; 213 pkt = rb->buf + align; 214 /* Move any available bytes to front of buffer: 215 * 'len' bytes already pointed to by 'packet', 216 * 'left' extra ones at the end */ 217 if (s->internal->packet != pkt) { 218 /* len > 0 */ 219 memmove(pkt, s->internal->packet, len + left); 220 s->internal->packet = pkt; 221 rb->offset = len + align; 222 } 223 224 if (n > (int)(rb->len - rb->offset)) { 225 /* does not happen */ 226 SSLerror(s, ERR_R_INTERNAL_ERROR); 227 return -1; 228 } 229 230 if (s->internal->read_ahead || SSL_is_dtls(s)) { 231 if (max < n) 232 max = n; 233 if (max > (int)(rb->len - rb->offset)) 234 max = rb->len - rb->offset; 235 } else { 236 /* ignore max parameter */ 237 max = n; 238 } 239 240 while (left < n) { 241 /* Now we have len+left bytes at the front of S3I(s)->rbuf.buf 242 * and need to read in more until we have len+n (up to 243 * len+max if possible) */ 244 245 errno = 0; 246 if (s->rbio != NULL) { 247 s->internal->rwstate = SSL_READING; 248 i = BIO_read(s->rbio, pkt + len + left, max - left); 249 } else { 250 SSLerror(s, SSL_R_READ_BIO_NOT_SET); 251 i = -1; 252 } 253 254 if (i <= 0) { 255 rb->left = left; 256 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 257 !SSL_is_dtls(s)) { 258 if (len + left == 0) 259 ssl3_release_read_buffer(s); 260 } 261 return (i); 262 } 263 left += i; 264 265 /* 266 * reads should *never* span multiple packets for DTLS because 267 * the underlying transport protocol is message oriented as 268 * opposed to byte oriented as in the TLS case. 269 */ 270 if (SSL_is_dtls(s)) { 271 if (n > left) 272 n = left; /* makes the while condition false */ 273 } 274 } 275 276 /* done reading, now the book-keeping */ 277 rb->offset += n; 278 rb->left = left - n; 279 s->internal->packet_length += n; 280 s->internal->rwstate = SSL_NOTHING; 281 282 return (n); 283 } 284 285 int 286 ssl3_packet_read(SSL *s, int plen) 287 { 288 int n; 289 290 n = ssl3_read_n(s, plen, S3I(s)->rbuf.len, 0); 291 if (n <= 0) 292 return n; 293 if (s->internal->packet_length < plen) 294 return s->internal->packet_length; 295 296 return plen; 297 } 298 299 int 300 ssl3_packet_extend(SSL *s, int plen) 301 { 302 int rlen, n; 303 304 if (s->internal->packet_length >= plen) 305 return plen; 306 rlen = plen - s->internal->packet_length; 307 308 n = ssl3_read_n(s, rlen, rlen, 1); 309 if (n <= 0) 310 return n; 311 if (s->internal->packet_length < plen) 312 return s->internal->packet_length; 313 314 return plen; 315 } 316 317 /* Call this to get a new input record. 318 * It will return <= 0 if more data is needed, normally due to an error 319 * or non-blocking IO. 320 * When it finishes, one packet has been decoded and can be found in 321 * ssl->s3->internal->rrec.type - is the type of record 322 * ssl->s3->internal->rrec.data, - data 323 * ssl->s3->internal->rrec.length, - number of bytes 324 */ 325 /* used only by ssl3_read_bytes */ 326 static int 327 ssl3_get_record(SSL *s) 328 { 329 SSL3_BUFFER_INTERNAL *rb = &(S3I(s)->rbuf); 330 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 331 uint8_t alert_desc; 332 uint8_t *out; 333 size_t out_len; 334 int al, n; 335 int ret = -1; 336 337 again: 338 /* check if we have the header */ 339 if ((s->internal->rstate != SSL_ST_READ_BODY) || 340 (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) { 341 CBS header; 342 uint16_t len, ssl_version; 343 uint8_t type; 344 345 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH); 346 if (n <= 0) 347 return (n); 348 349 s->internal->mac_packet = 1; 350 s->internal->rstate = SSL_ST_READ_BODY; 351 352 if (s->server && s->internal->first_packet) { 353 if ((ret = ssl_server_legacy_first_packet(s)) != 1) 354 return (ret); 355 ret = -1; 356 } 357 358 CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH); 359 360 /* Pull apart the header into the SSL3_RECORD_INTERNAL */ 361 if (!CBS_get_u8(&header, &type) || 362 !CBS_get_u16(&header, &ssl_version) || 363 !CBS_get_u16(&header, &len)) { 364 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 365 goto err; 366 } 367 368 rr->type = type; 369 rr->length = len; 370 371 /* Lets check version */ 372 if (!s->internal->first_packet && ssl_version != s->version) { 373 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && 374 !tls12_record_layer_write_protected(s->internal->rl)) { 375 /* Send back error using their minor version number :-) */ 376 s->version = ssl_version; 377 } 378 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 379 al = SSL_AD_PROTOCOL_VERSION; 380 goto fatal_err; 381 } 382 383 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) { 384 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 385 goto err; 386 } 387 388 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) { 389 al = SSL_AD_RECORD_OVERFLOW; 390 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG); 391 goto fatal_err; 392 } 393 } 394 395 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length); 396 if (n <= 0) 397 return (n); 398 if (n != SSL3_RT_HEADER_LENGTH + rr->length) 399 return (n); 400 401 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 402 403 /* 404 * A full record has now been read from the wire, which now needs 405 * to be processed. 406 */ 407 tls12_record_layer_set_version(s->internal->rl, s->version); 408 409 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, 410 s->internal->packet_length, &out, &out_len)) { 411 tls12_record_layer_alert(s->internal->rl, &alert_desc); 412 413 if (alert_desc == 0) 414 goto err; 415 416 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 417 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 418 else if (alert_desc == SSL_AD_BAD_RECORD_MAC) 419 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 420 421 al = alert_desc; 422 goto fatal_err; 423 } 424 425 rr->data = out; 426 rr->length = out_len; 427 rr->off = 0; 428 429 /* we have pulled in a full packet so zero things */ 430 s->internal->packet_length = 0; 431 432 if (rr->length == 0) { 433 /* 434 * Zero-length fragments are only permitted for application 435 * data, as per RFC 5246 section 6.2.1. 436 */ 437 if (rr->type != SSL3_RT_APPLICATION_DATA) { 438 SSLerror(s, SSL_R_BAD_LENGTH); 439 al = SSL_AD_UNEXPECTED_MESSAGE; 440 goto fatal_err; 441 } 442 443 /* 444 * CBC countermeasures for known IV weaknesses can legitimately 445 * insert a single empty record, so we allow ourselves to read 446 * once past a single empty record without forcing want_read. 447 */ 448 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 449 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 450 return -1; 451 } 452 if (s->internal->empty_record_count > 1) { 453 ssl_force_want_read(s); 454 return -1; 455 } 456 goto again; 457 } 458 459 s->internal->empty_record_count = 0; 460 461 return (1); 462 463 fatal_err: 464 ssl3_send_alert(s, SSL3_AL_FATAL, al); 465 err: 466 return (ret); 467 } 468 469 /* Call this to write data in records of type 'type' 470 * It will return <= 0 if not all data has been sent or non-blocking IO. 471 */ 472 int 473 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 474 { 475 const unsigned char *buf = buf_; 476 unsigned int tot, n, nw; 477 int i; 478 479 if (len < 0) { 480 SSLerror(s, ERR_R_INTERNAL_ERROR); 481 return -1; 482 } 483 484 s->internal->rwstate = SSL_NOTHING; 485 tot = S3I(s)->wnum; 486 S3I(s)->wnum = 0; 487 488 if (SSL_in_init(s) && !s->internal->in_handshake) { 489 i = s->internal->handshake_func(s); 490 if (i < 0) 491 return (i); 492 if (i == 0) { 493 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 494 return -1; 495 } 496 } 497 498 if (len < tot) 499 len = tot; 500 n = (len - tot); 501 for (;;) { 502 if (n > s->max_send_fragment) 503 nw = s->max_send_fragment; 504 else 505 nw = n; 506 507 i = do_ssl3_write(s, type, &(buf[tot]), nw); 508 if (i <= 0) { 509 S3I(s)->wnum = tot; 510 return i; 511 } 512 513 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 514 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 515 /* 516 * Next chunk of data should get another prepended 517 * empty fragment in ciphersuites with known-IV 518 * weakness. 519 */ 520 S3I(s)->empty_fragment_done = 0; 521 522 return tot + i; 523 } 524 525 n -= i; 526 tot += i; 527 } 528 } 529 530 static int 531 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 532 { 533 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 534 SSL_SESSION *sess = s->session; 535 int need_empty_fragment = 0; 536 size_t align, out_len; 537 uint16_t version; 538 CBB cbb; 539 int ret; 540 541 memset(&cbb, 0, sizeof(cbb)); 542 543 if (wb->buf == NULL) 544 if (!ssl3_setup_write_buffer(s)) 545 return -1; 546 547 /* 548 * First check if there is a SSL3_BUFFER_INTERNAL still being written 549 * out. This will happen with non blocking IO. 550 */ 551 if (wb->left != 0) 552 return (ssl3_write_pending(s, type, buf, len)); 553 554 /* If we have an alert to send, let's send it. */ 555 if (S3I(s)->alert_dispatch) { 556 if ((ret = ssl3_dispatch_alert(s)) <= 0) 557 return (ret); 558 /* If it went, fall through and send more stuff. */ 559 560 /* We may have released our buffer, if so get it again. */ 561 if (wb->buf == NULL) 562 if (!ssl3_setup_write_buffer(s)) 563 return -1; 564 } 565 566 if (len == 0) 567 return 0; 568 569 /* 570 * Some servers hang if initial client hello is larger than 256 571 * bytes and record version number > TLS 1.0. 572 */ 573 version = s->version; 574 if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B && 575 !s->internal->renegotiate && 576 S3I(s)->hs.our_max_tls_version > TLS1_VERSION) 577 version = TLS1_VERSION; 578 579 /* 580 * Countermeasure against known-IV weakness in CBC ciphersuites 581 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this 582 * is unnecessary for AEAD. 583 */ 584 if (sess != NULL && tls12_record_layer_write_protected(s->internal->rl)) { 585 if (S3I(s)->need_empty_fragments && 586 !S3I(s)->empty_fragment_done && 587 type == SSL3_RT_APPLICATION_DATA) 588 need_empty_fragment = 1; 589 } 590 591 /* 592 * An extra fragment would be a couple of cipher blocks, which would 593 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 594 * payload, then we can just simply pretend we have two headers. 595 */ 596 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 597 if (need_empty_fragment) 598 align += SSL3_RT_HEADER_LENGTH; 599 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 600 wb->offset = align; 601 602 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) 603 goto err; 604 605 tls12_record_layer_set_version(s->internal->rl, version); 606 607 if (need_empty_fragment) { 608 if (!tls12_record_layer_seal_record(s->internal->rl, type, 609 buf, 0, &cbb)) 610 goto err; 611 S3I(s)->empty_fragment_done = 1; 612 } 613 614 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 615 goto err; 616 617 if (!CBB_finish(&cbb, NULL, &out_len)) 618 goto err; 619 620 wb->left = out_len; 621 622 /* 623 * Memorize arguments so that ssl3_write_pending can detect 624 * bad write retries later. 625 */ 626 S3I(s)->wpend_tot = len; 627 S3I(s)->wpend_buf = buf; 628 S3I(s)->wpend_type = type; 629 S3I(s)->wpend_ret = len; 630 631 /* We now just need to write the buffer. */ 632 return ssl3_write_pending(s, type, buf, len); 633 634 err: 635 CBB_cleanup(&cbb); 636 637 return -1; 638 } 639 640 /* if S3I(s)->wbuf.left != 0, we need to call this */ 641 int 642 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 643 { 644 int i; 645 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 646 647 /* XXXX */ 648 if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) && 649 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 650 (S3I(s)->wpend_type != type)) { 651 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 652 return (-1); 653 } 654 655 for (;;) { 656 errno = 0; 657 if (s->wbio != NULL) { 658 s->internal->rwstate = SSL_WRITING; 659 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), 660 (unsigned int)wb->left); 661 } else { 662 SSLerror(s, SSL_R_BIO_NOT_SET); 663 i = -1; 664 } 665 if (i == wb->left) { 666 wb->left = 0; 667 wb->offset += i; 668 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 669 !SSL_is_dtls(s)) 670 ssl3_release_write_buffer(s); 671 s->internal->rwstate = SSL_NOTHING; 672 return (S3I(s)->wpend_ret); 673 } else if (i <= 0) { 674 /* 675 * For DTLS, just drop it. That's kind of the 676 * whole point in using a datagram service. 677 */ 678 if (SSL_is_dtls(s)) 679 wb->left = 0; 680 return (i); 681 } 682 wb->offset += i; 683 wb->left -= i; 684 } 685 } 686 687 /* Return up to 'len' payload bytes received in 'type' records. 688 * 'type' is one of the following: 689 * 690 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 691 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 692 * - 0 (during a shutdown, no data has to be returned) 693 * 694 * If we don't have stored data to work from, read a SSL/TLS record first 695 * (possibly multiple records if we still don't have anything to return). 696 * 697 * This function must handle any surprises the peer may have for us, such as 698 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 699 * a surprise, but handled as if it were), or renegotiation requests. 700 * Also if record payloads contain fragments too small to process, we store 701 * them until there is enough for the respective protocol (the record protocol 702 * may use arbitrary fragmentation and even interleaving): 703 * Change cipher spec protocol 704 * just 1 byte needed, no need for keeping anything stored 705 * Alert protocol 706 * 2 bytes needed (AlertLevel, AlertDescription) 707 * Handshake protocol 708 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 709 * to detect unexpected Client Hello and Hello Request messages 710 * here, anything else is handled by higher layers 711 * Application data protocol 712 * none of our business 713 */ 714 int 715 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 716 { 717 int al, i, ret, rrcount = 0; 718 unsigned int n; 719 SSL3_RECORD_INTERNAL *rr; 720 721 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 722 if (!ssl3_setup_read_buffer(s)) 723 return (-1); 724 725 if (len < 0) { 726 SSLerror(s, ERR_R_INTERNAL_ERROR); 727 return -1; 728 } 729 730 if ((type && type != SSL3_RT_APPLICATION_DATA && 731 type != SSL3_RT_HANDSHAKE) || 732 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 733 SSLerror(s, ERR_R_INTERNAL_ERROR); 734 return -1; 735 } 736 737 if ((type == SSL3_RT_HANDSHAKE) && 738 (S3I(s)->handshake_fragment_len > 0)) { 739 /* (partially) satisfy request from storage */ 740 unsigned char *src = S3I(s)->handshake_fragment; 741 unsigned char *dst = buf; 742 unsigned int k; 743 744 /* peek == 0 */ 745 n = 0; 746 while ((len > 0) && (S3I(s)->handshake_fragment_len > 0)) { 747 *dst++ = *src++; 748 len--; 749 S3I(s)->handshake_fragment_len--; 750 n++; 751 } 752 /* move any remaining fragment bytes: */ 753 for (k = 0; k < S3I(s)->handshake_fragment_len; k++) 754 S3I(s)->handshake_fragment[k] = *src++; 755 return n; 756 } 757 758 /* 759 * Now S3I(s)->handshake_fragment_len == 0 if 760 * type == SSL3_RT_HANDSHAKE. 761 */ 762 if (!s->internal->in_handshake && SSL_in_init(s)) { 763 /* type == SSL3_RT_APPLICATION_DATA */ 764 i = s->internal->handshake_func(s); 765 if (i < 0) 766 return (i); 767 if (i == 0) { 768 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 769 return (-1); 770 } 771 } 772 773 start: 774 /* 775 * Do not process more than three consecutive records, otherwise the 776 * peer can cause us to loop indefinitely. Instead, return with an 777 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 778 * processing. In the future, the total number of non-handshake and 779 * non-application data records per connection should probably also be 780 * limited... 781 */ 782 if (rrcount++ >= 3) { 783 ssl_force_want_read(s); 784 return -1; 785 } 786 787 s->internal->rwstate = SSL_NOTHING; 788 789 /* 790 * S3I(s)->rrec.type - is the type of record 791 * S3I(s)->rrec.data, - data 792 * S3I(s)->rrec.off, - offset into 'data' for next read 793 * S3I(s)->rrec.length, - number of bytes. 794 */ 795 rr = &(S3I(s)->rrec); 796 797 /* get new packet if necessary */ 798 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 799 ret = ssl3_get_record(s); 800 if (ret <= 0) 801 return (ret); 802 } 803 804 /* we now have a packet which can be read and processed */ 805 806 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 807 * reset by ssl3_get_finished */ 808 && (rr->type != SSL3_RT_HANDSHAKE)) { 809 al = SSL_AD_UNEXPECTED_MESSAGE; 810 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 811 goto fatal_err; 812 } 813 814 /* If the other end has shut down, throw anything we read away 815 * (even in 'peek' mode) */ 816 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 817 rr->length = 0; 818 s->internal->rwstate = SSL_NOTHING; 819 return (0); 820 } 821 822 823 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 824 if (type == rr->type) { 825 /* make sure that we are not getting application data when we 826 * are doing a handshake for the first time */ 827 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 828 !tls12_record_layer_read_protected(s->internal->rl)) { 829 al = SSL_AD_UNEXPECTED_MESSAGE; 830 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 831 goto fatal_err; 832 } 833 834 if (len <= 0) 835 return (len); 836 837 if ((unsigned int)len > rr->length) 838 n = rr->length; 839 else 840 n = (unsigned int)len; 841 842 memcpy(buf, &(rr->data[rr->off]), n); 843 if (!peek) { 844 memset(&(rr->data[rr->off]), 0, n); 845 rr->length -= n; 846 rr->off += n; 847 if (rr->length == 0) { 848 s->internal->rstate = SSL_ST_READ_HEADER; 849 rr->off = 0; 850 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 851 S3I(s)->rbuf.left == 0) 852 ssl3_release_read_buffer(s); 853 } 854 } 855 return (n); 856 } 857 858 859 /* If we get here, then type != rr->type; if we have a handshake 860 * message, then it was unexpected (Hello Request or Client Hello). */ 861 862 { 863 /* 864 * In case of record types for which we have 'fragment' 865 * storage, * fill that so that we can process the data 866 * at a fixed place. 867 */ 868 unsigned int dest_maxlen = 0; 869 unsigned char *dest = NULL; 870 unsigned int *dest_len = NULL; 871 872 if (rr->type == SSL3_RT_HANDSHAKE) { 873 dest_maxlen = sizeof S3I(s)->handshake_fragment; 874 dest = S3I(s)->handshake_fragment; 875 dest_len = &S3I(s)->handshake_fragment_len; 876 } else if (rr->type == SSL3_RT_ALERT) { 877 dest_maxlen = sizeof S3I(s)->alert_fragment; 878 dest = S3I(s)->alert_fragment; 879 dest_len = &S3I(s)->alert_fragment_len; 880 } 881 if (dest_maxlen > 0) { 882 /* available space in 'dest' */ 883 n = dest_maxlen - *dest_len; 884 if (rr->length < n) 885 n = rr->length; /* available bytes */ 886 887 /* now move 'n' bytes: */ 888 while (n-- > 0) { 889 dest[(*dest_len)++] = rr->data[rr->off++]; 890 rr->length--; 891 } 892 893 if (*dest_len < dest_maxlen) 894 goto start; /* fragment was too small */ 895 } 896 } 897 898 /* S3I(s)->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; 899 * S3I(s)->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT. 900 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 901 902 /* If we are a client, check for an incoming 'Hello Request': */ 903 if ((!s->server) && (S3I(s)->handshake_fragment_len >= 4) && 904 (S3I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 905 (s->session != NULL) && (s->session->cipher != NULL)) { 906 S3I(s)->handshake_fragment_len = 0; 907 908 if ((S3I(s)->handshake_fragment[1] != 0) || 909 (S3I(s)->handshake_fragment[2] != 0) || 910 (S3I(s)->handshake_fragment[3] != 0)) { 911 al = SSL_AD_DECODE_ERROR; 912 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 913 goto fatal_err; 914 } 915 916 ssl_msg_callback(s, 0, SSL3_RT_HANDSHAKE, 917 S3I(s)->handshake_fragment, 4); 918 919 if (SSL_is_init_finished(s) && 920 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 921 !S3I(s)->renegotiate) { 922 ssl3_renegotiate(s); 923 if (ssl3_renegotiate_check(s)) { 924 i = s->internal->handshake_func(s); 925 if (i < 0) 926 return (i); 927 if (i == 0) { 928 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 929 return (-1); 930 } 931 932 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 933 if (S3I(s)->rbuf.left == 0) { 934 /* no read-ahead left? */ 935 /* In the case where we try to read application data, 936 * but we trigger an SSL handshake, we return -1 with 937 * the retry option set. Otherwise renegotiation may 938 * cause nasty problems in the blocking world */ 939 ssl_force_want_read(s); 940 return (-1); 941 } 942 } 943 } 944 } 945 /* we either finished a handshake or ignored the request, 946 * now try again to obtain the (application) data we were asked for */ 947 goto start; 948 } 949 /* Disallow client initiated renegotiation if configured. */ 950 if (s->server && SSL_is_init_finished(s) && 951 S3I(s)->handshake_fragment_len >= 4 && 952 S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO && 953 (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) { 954 al = SSL_AD_NO_RENEGOTIATION; 955 goto fatal_err; 956 } 957 /* If we are a server and get a client hello when renegotiation isn't 958 * allowed send back a no renegotiation alert and carry on. 959 * WARNING: experimental code, needs reviewing (steve) 960 */ 961 if (s->server && 962 SSL_is_init_finished(s) && 963 !S3I(s)->send_connection_binding && 964 (S3I(s)->handshake_fragment_len >= 4) && 965 (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && 966 (s->session != NULL) && (s->session->cipher != NULL)) { 967 /*S3I(s)->handshake_fragment_len = 0;*/ 968 rr->length = 0; 969 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 970 goto start; 971 } 972 if (S3I(s)->alert_fragment_len >= 2) { 973 int alert_level = S3I(s)->alert_fragment[0]; 974 int alert_descr = S3I(s)->alert_fragment[1]; 975 976 S3I(s)->alert_fragment_len = 0; 977 978 ssl_msg_callback(s, 0, SSL3_RT_ALERT, 979 S3I(s)->alert_fragment, 2); 980 981 ssl_info_callback(s, SSL_CB_READ_ALERT, 982 (alert_level << 8) | alert_descr); 983 984 if (alert_level == SSL3_AL_WARNING) { 985 S3I(s)->warn_alert = alert_descr; 986 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 987 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 988 return (0); 989 } 990 /* This is a warning but we receive it if we requested 991 * renegotiation and the peer denied it. Terminate with 992 * a fatal alert because if application tried to 993 * renegotiatie it presumably had a good reason and 994 * expects it to succeed. 995 * 996 * In future we might have a renegotiation where we 997 * don't care if the peer refused it where we carry on. 998 */ 999 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 1000 al = SSL_AD_HANDSHAKE_FAILURE; 1001 SSLerror(s, SSL_R_NO_RENEGOTIATION); 1002 goto fatal_err; 1003 } 1004 } else if (alert_level == SSL3_AL_FATAL) { 1005 s->internal->rwstate = SSL_NOTHING; 1006 S3I(s)->fatal_alert = alert_descr; 1007 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 1008 ERR_asprintf_error_data("SSL alert number %d", 1009 alert_descr); 1010 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 1011 SSL_CTX_remove_session(s->ctx, s->session); 1012 return (0); 1013 } else { 1014 al = SSL_AD_ILLEGAL_PARAMETER; 1015 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 1016 goto fatal_err; 1017 } 1018 1019 goto start; 1020 } 1021 1022 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 1023 /* but we have not received a shutdown */ 1024 s->internal->rwstate = SSL_NOTHING; 1025 rr->length = 0; 1026 return (0); 1027 } 1028 1029 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1030 /* 'Change Cipher Spec' is just a single byte, so we know 1031 * exactly what the record payload has to look like */ 1032 if ((rr->length != 1) || (rr->off != 0) || 1033 (rr->data[0] != SSL3_MT_CCS)) { 1034 al = SSL_AD_ILLEGAL_PARAMETER; 1035 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1036 goto fatal_err; 1037 } 1038 1039 /* Check we have a cipher to change to */ 1040 if (S3I(s)->hs.cipher == NULL) { 1041 al = SSL_AD_UNEXPECTED_MESSAGE; 1042 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1043 goto fatal_err; 1044 } 1045 1046 /* Check that we should be receiving a Change Cipher Spec. */ 1047 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) { 1048 al = SSL_AD_UNEXPECTED_MESSAGE; 1049 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1050 goto fatal_err; 1051 } 1052 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 1053 1054 rr->length = 0; 1055 1056 ssl_msg_callback(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1); 1057 1058 S3I(s)->change_cipher_spec = 1; 1059 if (!ssl3_do_change_cipher_spec(s)) 1060 goto err; 1061 else 1062 goto start; 1063 } 1064 1065 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1066 if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) { 1067 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1068 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1069 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1070 s->internal->renegotiate = 1; 1071 s->internal->new_session = 1; 1072 } 1073 i = s->internal->handshake_func(s); 1074 if (i < 0) 1075 return (i); 1076 if (i == 0) { 1077 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1078 return (-1); 1079 } 1080 1081 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1082 if (S3I(s)->rbuf.left == 0) { /* no read-ahead left? */ 1083 /* In the case where we try to read application data, 1084 * but we trigger an SSL handshake, we return -1 with 1085 * the retry option set. Otherwise renegotiation may 1086 * cause nasty problems in the blocking world */ 1087 ssl_force_want_read(s); 1088 return (-1); 1089 } 1090 } 1091 goto start; 1092 } 1093 1094 switch (rr->type) { 1095 default: 1096 /* 1097 * TLS up to v1.1 just ignores unknown message types: 1098 * TLS v1.2 give an unexpected message alert. 1099 */ 1100 if (s->version >= TLS1_VERSION && 1101 s->version <= TLS1_1_VERSION) { 1102 rr->length = 0; 1103 goto start; 1104 } 1105 al = SSL_AD_UNEXPECTED_MESSAGE; 1106 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1107 goto fatal_err; 1108 case SSL3_RT_CHANGE_CIPHER_SPEC: 1109 case SSL3_RT_ALERT: 1110 case SSL3_RT_HANDSHAKE: 1111 /* we already handled all of these, with the possible exception 1112 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1113 * should not happen when type != rr->type */ 1114 al = SSL_AD_UNEXPECTED_MESSAGE; 1115 SSLerror(s, ERR_R_INTERNAL_ERROR); 1116 goto fatal_err; 1117 case SSL3_RT_APPLICATION_DATA: 1118 /* At this point, we were expecting handshake data, 1119 * but have application data. If the library was 1120 * running inside ssl3_read() (i.e. in_read_app_data 1121 * is set) and it makes sense to read application data 1122 * at this point (session renegotiation not yet started), 1123 * we will indulge it. 1124 */ 1125 if (S3I(s)->in_read_app_data && 1126 (S3I(s)->total_renegotiations != 0) && 1127 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1128 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1129 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || 1130 ((S3I(s)->hs.state & SSL_ST_ACCEPT) && 1131 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1132 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1133 S3I(s)->in_read_app_data = 2; 1134 return (-1); 1135 } else { 1136 al = SSL_AD_UNEXPECTED_MESSAGE; 1137 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1138 goto fatal_err; 1139 } 1140 } 1141 /* not reached */ 1142 1143 fatal_err: 1144 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1145 err: 1146 return (-1); 1147 } 1148 1149 int 1150 ssl3_do_change_cipher_spec(SSL *s) 1151 { 1152 if (S3I(s)->hs.tls12.key_block == NULL) { 1153 if (s->session == NULL || s->session->master_key_length == 0) { 1154 /* might happen if dtls1_read_bytes() calls this */ 1155 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1156 return (0); 1157 } 1158 1159 s->session->cipher = S3I(s)->hs.cipher; 1160 if (!tls1_setup_key_block(s)) 1161 return (0); 1162 } 1163 1164 if (!tls1_change_read_cipher_state(s)) 1165 return (0); 1166 1167 /* 1168 * We have to record the message digest at this point so we can get it 1169 * before we read the finished message. 1170 */ 1171 if (!tls12_derive_peer_finished(s)) 1172 return (0); 1173 1174 return (1); 1175 } 1176 1177 static int 1178 ssl3_write_alert(SSL *s) 1179 { 1180 if (SSL_is_dtls(s)) 1181 return do_dtls1_write(s, SSL3_RT_ALERT, S3I(s)->send_alert, 1182 sizeof(S3I(s)->send_alert)); 1183 1184 return do_ssl3_write(s, SSL3_RT_ALERT, S3I(s)->send_alert, 1185 sizeof(S3I(s)->send_alert)); 1186 } 1187 1188 int 1189 ssl3_send_alert(SSL *s, int level, int desc) 1190 { 1191 /* If alert is fatal, remove session from cache. */ 1192 if (level == SSL3_AL_FATAL) 1193 SSL_CTX_remove_session(s->ctx, s->session); 1194 1195 S3I(s)->alert_dispatch = 1; 1196 S3I(s)->send_alert[0] = level; 1197 S3I(s)->send_alert[1] = desc; 1198 1199 /* 1200 * If data is still being written out, the alert will be dispatched at 1201 * some point in the future. 1202 */ 1203 if (S3I(s)->wbuf.left != 0) 1204 return -1; 1205 1206 return ssl3_dispatch_alert(s); 1207 } 1208 1209 int 1210 ssl3_dispatch_alert(SSL *s) 1211 { 1212 int ret; 1213 1214 S3I(s)->alert_dispatch = 0; 1215 if ((ret = ssl3_write_alert(s)) <= 0) { 1216 S3I(s)->alert_dispatch = 1; 1217 return ret; 1218 } 1219 1220 /* 1221 * Alert sent to BIO. If it is important, flush it now. 1222 * If the message does not get sent due to non-blocking IO, 1223 * we will not worry too much. 1224 */ 1225 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1226 (void)BIO_flush(s->wbio); 1227 1228 ssl_msg_callback(s, 1, SSL3_RT_ALERT, S3I(s)->send_alert, 2); 1229 1230 ssl_info_callback(s, SSL_CB_WRITE_ALERT, 1231 (S3I(s)->send_alert[0] << 8) | S3I(s)->send_alert[1]); 1232 1233 return ret; 1234 } 1235