1 /* $OpenBSD: ssl_pkt.c,v 1.45 2021/06/29 18:43:49 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 "ssl_locl.h" 120 121 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, 122 unsigned int len); 123 static int ssl3_get_record(SSL *s); 124 125 /* 126 * Force a WANT_READ return for certain error conditions where 127 * we don't want to spin internally. 128 */ 129 static void 130 ssl_force_want_read(SSL *s) 131 { 132 BIO * bio; 133 134 bio = SSL_get_rbio(s); 135 BIO_clear_retry_flags(bio); 136 BIO_set_retry_read(bio); 137 s->internal->rwstate = SSL_READING; 138 } 139 140 /* 141 * If extend == 0, obtain new n-byte packet; if extend == 1, increase 142 * packet by another n bytes. 143 * The packet will be in the sub-array of S3I(s)->rbuf.buf specified 144 * by s->internal->packet and s->internal->packet_length. 145 * (If s->internal->read_ahead is set, 'max' bytes may be stored in rbuf 146 * [plus s->internal->packet_length bytes if extend == 1].) 147 */ 148 static int 149 ssl3_read_n(SSL *s, int n, int max, int extend) 150 { 151 SSL3_BUFFER_INTERNAL *rb = &(S3I(s)->rbuf); 152 int i, len, left; 153 size_t align; 154 unsigned char *pkt; 155 156 if (n <= 0) 157 return n; 158 159 if (rb->buf == NULL) 160 if (!ssl3_setup_read_buffer(s)) 161 return -1; 162 163 left = rb->left; 164 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH; 165 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 166 167 if (!extend) { 168 /* start with empty packet ... */ 169 if (left == 0) 170 rb->offset = align; 171 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { 172 /* check if next packet length is large 173 * enough to justify payload alignment... */ 174 pkt = rb->buf + rb->offset; 175 if (pkt[0] == SSL3_RT_APPLICATION_DATA && 176 (pkt[3]<<8|pkt[4]) >= 128) { 177 /* Note that even if packet is corrupted 178 * and its length field is insane, we can 179 * only be led to wrong decision about 180 * whether memmove will occur or not. 181 * Header values has no effect on memmove 182 * arguments and therefore no buffer 183 * overrun can be triggered. */ 184 memmove(rb->buf + align, pkt, left); 185 rb->offset = align; 186 } 187 } 188 s->internal->packet = rb->buf + rb->offset; 189 s->internal->packet_length = 0; 190 /* ... now we can act as if 'extend' was set */ 191 } 192 193 /* For DTLS/UDP reads should not span multiple packets 194 * because the read operation returns the whole packet 195 * at once (as long as it fits into the buffer). */ 196 if (SSL_is_dtls(s)) { 197 if (left > 0 && n > left) 198 n = left; 199 } 200 201 /* if there is enough in the buffer from a previous read, take some */ 202 if (left >= n) { 203 s->internal->packet_length += n; 204 rb->left = left - n; 205 rb->offset += n; 206 return (n); 207 } 208 209 /* else we need to read more data */ 210 211 len = s->internal->packet_length; 212 pkt = rb->buf + align; 213 /* Move any available bytes to front of buffer: 214 * 'len' bytes already pointed to by 'packet', 215 * 'left' extra ones at the end */ 216 if (s->internal->packet != pkt) { 217 /* len > 0 */ 218 memmove(pkt, s->internal->packet, len + left); 219 s->internal->packet = pkt; 220 rb->offset = len + align; 221 } 222 223 if (n > (int)(rb->len - rb->offset)) { 224 /* does not happen */ 225 SSLerror(s, ERR_R_INTERNAL_ERROR); 226 return -1; 227 } 228 229 if (s->internal->read_ahead || SSL_is_dtls(s)) { 230 if (max < n) 231 max = n; 232 if (max > (int)(rb->len - rb->offset)) 233 max = rb->len - rb->offset; 234 } else { 235 /* ignore max parameter */ 236 max = n; 237 } 238 239 while (left < n) { 240 /* Now we have len+left bytes at the front of S3I(s)->rbuf.buf 241 * and need to read in more until we have len+n (up to 242 * len+max if possible) */ 243 244 errno = 0; 245 if (s->rbio != NULL) { 246 s->internal->rwstate = SSL_READING; 247 i = BIO_read(s->rbio, pkt + len + left, max - left); 248 } else { 249 SSLerror(s, SSL_R_READ_BIO_NOT_SET); 250 i = -1; 251 } 252 253 if (i <= 0) { 254 rb->left = left; 255 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 256 !SSL_is_dtls(s)) { 257 if (len + left == 0) 258 ssl3_release_read_buffer(s); 259 } 260 return (i); 261 } 262 left += i; 263 264 /* 265 * reads should *never* span multiple packets for DTLS because 266 * the underlying transport protocol is message oriented as 267 * opposed to byte oriented as in the TLS case. 268 */ 269 if (SSL_is_dtls(s)) { 270 if (n > left) 271 n = left; /* makes the while condition false */ 272 } 273 } 274 275 /* done reading, now the book-keeping */ 276 rb->offset += n; 277 rb->left = left - n; 278 s->internal->packet_length += n; 279 s->internal->rwstate = SSL_NOTHING; 280 281 return (n); 282 } 283 284 int 285 ssl3_packet_read(SSL *s, int plen) 286 { 287 int n; 288 289 n = ssl3_read_n(s, plen, S3I(s)->rbuf.len, 0); 290 if (n <= 0) 291 return n; 292 if (s->internal->packet_length < plen) 293 return s->internal->packet_length; 294 295 return plen; 296 } 297 298 int 299 ssl3_packet_extend(SSL *s, int plen) 300 { 301 int rlen, n; 302 303 if (s->internal->packet_length >= plen) 304 return plen; 305 rlen = plen - s->internal->packet_length; 306 307 n = ssl3_read_n(s, rlen, rlen, 1); 308 if (n <= 0) 309 return n; 310 if (s->internal->packet_length < plen) 311 return s->internal->packet_length; 312 313 return plen; 314 } 315 316 /* Call this to get a new input record. 317 * It will return <= 0 if more data is needed, normally due to an error 318 * or non-blocking IO. 319 * When it finishes, one packet has been decoded and can be found in 320 * ssl->s3->internal->rrec.type - is the type of record 321 * ssl->s3->internal->rrec.data, - data 322 * ssl->s3->internal->rrec.length, - number of bytes 323 */ 324 /* used only by ssl3_read_bytes */ 325 static int 326 ssl3_get_record(SSL *s) 327 { 328 SSL3_BUFFER_INTERNAL *rb = &(S3I(s)->rbuf); 329 SSL3_RECORD_INTERNAL *rr = &(S3I(s)->rrec); 330 uint8_t alert_desc; 331 uint8_t *out; 332 size_t out_len; 333 int al, n; 334 int ret = -1; 335 336 again: 337 /* check if we have the header */ 338 if ((s->internal->rstate != SSL_ST_READ_BODY) || 339 (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) { 340 CBS header; 341 uint16_t len, ssl_version; 342 uint8_t type; 343 344 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH); 345 if (n <= 0) 346 return (n); 347 348 s->internal->mac_packet = 1; 349 s->internal->rstate = SSL_ST_READ_BODY; 350 351 if (s->server && s->internal->first_packet) { 352 if ((ret = ssl_server_legacy_first_packet(s)) != 1) 353 return (ret); 354 ret = -1; 355 } 356 357 CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH); 358 359 /* Pull apart the header into the SSL3_RECORD_INTERNAL */ 360 if (!CBS_get_u8(&header, &type) || 361 !CBS_get_u16(&header, &ssl_version) || 362 !CBS_get_u16(&header, &len)) { 363 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 364 goto err; 365 } 366 367 rr->type = type; 368 rr->length = len; 369 370 /* Lets check version */ 371 if (!s->internal->first_packet && ssl_version != s->version) { 372 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && 373 !tls12_record_layer_write_protected(s->internal->rl)) { 374 /* Send back error using their minor version number :-) */ 375 s->version = ssl_version; 376 } 377 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 378 al = SSL_AD_PROTOCOL_VERSION; 379 goto fatal_err; 380 } 381 382 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) { 383 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 384 goto err; 385 } 386 387 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) { 388 al = SSL_AD_RECORD_OVERFLOW; 389 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG); 390 goto fatal_err; 391 } 392 } 393 394 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length); 395 if (n <= 0) 396 return (n); 397 if (n != SSL3_RT_HEADER_LENGTH + rr->length) 398 return (n); 399 400 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 401 402 /* 403 * A full record has now been read from the wire, which now needs 404 * to be processed. 405 */ 406 tls12_record_layer_set_version(s->internal->rl, s->version); 407 408 if (!tls12_record_layer_open_record(s->internal->rl, s->internal->packet, 409 s->internal->packet_length, &out, &out_len)) { 410 tls12_record_layer_alert(s->internal->rl, &alert_desc); 411 412 if (alert_desc == 0) 413 goto err; 414 415 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 416 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 417 else if (alert_desc == SSL_AD_BAD_RECORD_MAC) 418 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 419 420 al = alert_desc; 421 goto fatal_err; 422 } 423 424 rr->data = out; 425 rr->length = out_len; 426 rr->off = 0; 427 428 /* we have pulled in a full packet so zero things */ 429 s->internal->packet_length = 0; 430 431 if (rr->length == 0) { 432 /* 433 * Zero-length fragments are only permitted for application 434 * data, as per RFC 5246 section 6.2.1. 435 */ 436 if (rr->type != SSL3_RT_APPLICATION_DATA) { 437 SSLerror(s, SSL_R_BAD_LENGTH); 438 al = SSL_AD_UNEXPECTED_MESSAGE; 439 goto fatal_err; 440 } 441 442 /* 443 * CBC countermeasures for known IV weaknesses can legitimately 444 * insert a single empty record, so we allow ourselves to read 445 * once past a single empty record without forcing want_read. 446 */ 447 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 448 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 449 return -1; 450 } 451 if (s->internal->empty_record_count > 1) { 452 ssl_force_want_read(s); 453 return -1; 454 } 455 goto again; 456 } 457 458 s->internal->empty_record_count = 0; 459 460 return (1); 461 462 fatal_err: 463 ssl3_send_alert(s, SSL3_AL_FATAL, al); 464 err: 465 return (ret); 466 } 467 468 /* Call this to write data in records of type 'type' 469 * It will return <= 0 if not all data has been sent or non-blocking IO. 470 */ 471 int 472 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 473 { 474 const unsigned char *buf = buf_; 475 unsigned int tot, n, nw; 476 int i; 477 478 if (len < 0) { 479 SSLerror(s, ERR_R_INTERNAL_ERROR); 480 return -1; 481 } 482 483 s->internal->rwstate = SSL_NOTHING; 484 tot = S3I(s)->wnum; 485 S3I(s)->wnum = 0; 486 487 if (SSL_in_init(s) && !s->internal->in_handshake) { 488 i = s->internal->handshake_func(s); 489 if (i < 0) 490 return (i); 491 if (i == 0) { 492 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 493 return -1; 494 } 495 } 496 497 if (len < tot) 498 len = tot; 499 n = (len - tot); 500 for (;;) { 501 if (n > s->max_send_fragment) 502 nw = s->max_send_fragment; 503 else 504 nw = n; 505 506 i = do_ssl3_write(s, type, &(buf[tot]), nw); 507 if (i <= 0) { 508 S3I(s)->wnum = tot; 509 return i; 510 } 511 512 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 513 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 514 /* 515 * Next chunk of data should get another prepended 516 * empty fragment in ciphersuites with known-IV 517 * weakness. 518 */ 519 S3I(s)->empty_fragment_done = 0; 520 521 return tot + i; 522 } 523 524 n -= i; 525 tot += i; 526 } 527 } 528 529 static int 530 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 531 { 532 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 533 SSL_SESSION *sess = s->session; 534 int need_empty_fragment = 0; 535 size_t align, out_len; 536 uint16_t version; 537 CBB cbb; 538 int ret; 539 540 memset(&cbb, 0, sizeof(cbb)); 541 542 if (wb->buf == NULL) 543 if (!ssl3_setup_write_buffer(s)) 544 return -1; 545 546 /* 547 * First check if there is a SSL3_BUFFER_INTERNAL still being written 548 * out. This will happen with non blocking IO. 549 */ 550 if (wb->left != 0) 551 return (ssl3_write_pending(s, type, buf, len)); 552 553 /* If we have an alert to send, let's send it. */ 554 if (S3I(s)->alert_dispatch) { 555 if ((ret = s->method->ssl_dispatch_alert(s)) <= 0) 556 return (ret); 557 /* If it went, fall through and send more stuff. */ 558 559 /* We may have released our buffer, if so get it again. */ 560 if (wb->buf == NULL) 561 if (!ssl3_setup_write_buffer(s)) 562 return -1; 563 } 564 565 if (len == 0) 566 return 0; 567 568 /* 569 * Some servers hang if initial client hello is larger than 256 570 * bytes and record version number > TLS 1.0. 571 */ 572 version = s->version; 573 if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B && 574 !s->internal->renegotiate && 575 S3I(s)->hs.our_max_tls_version > TLS1_VERSION) 576 version = TLS1_VERSION; 577 578 /* 579 * Countermeasure against known-IV weakness in CBC ciphersuites 580 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this 581 * is unnecessary for AEAD. 582 */ 583 if (sess != NULL && tls12_record_layer_write_protected(s->internal->rl)) { 584 if (S3I(s)->need_empty_fragments && 585 !S3I(s)->empty_fragment_done && 586 type == SSL3_RT_APPLICATION_DATA) 587 need_empty_fragment = 1; 588 } 589 590 /* 591 * An extra fragment would be a couple of cipher blocks, which would 592 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 593 * payload, then we can just simply pretend we have two headers. 594 */ 595 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 596 if (need_empty_fragment) 597 align += SSL3_RT_HEADER_LENGTH; 598 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 599 wb->offset = align; 600 601 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) 602 goto err; 603 604 tls12_record_layer_set_version(s->internal->rl, version); 605 606 if (need_empty_fragment) { 607 if (!tls12_record_layer_seal_record(s->internal->rl, type, 608 buf, 0, &cbb)) 609 goto err; 610 S3I(s)->empty_fragment_done = 1; 611 } 612 613 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 614 goto err; 615 616 if (!CBB_finish(&cbb, NULL, &out_len)) 617 goto err; 618 619 wb->left = out_len; 620 621 /* 622 * Memorize arguments so that ssl3_write_pending can detect 623 * bad write retries later. 624 */ 625 S3I(s)->wpend_tot = len; 626 S3I(s)->wpend_buf = buf; 627 S3I(s)->wpend_type = type; 628 S3I(s)->wpend_ret = len; 629 630 /* We now just need to write the buffer. */ 631 return ssl3_write_pending(s, type, buf, len); 632 633 err: 634 CBB_cleanup(&cbb); 635 636 return -1; 637 } 638 639 /* if S3I(s)->wbuf.left != 0, we need to call this */ 640 int 641 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 642 { 643 int i; 644 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 645 646 /* XXXX */ 647 if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) && 648 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 649 (S3I(s)->wpend_type != type)) { 650 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 651 return (-1); 652 } 653 654 for (;;) { 655 errno = 0; 656 if (s->wbio != NULL) { 657 s->internal->rwstate = SSL_WRITING; 658 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), 659 (unsigned int)wb->left); 660 } else { 661 SSLerror(s, SSL_R_BIO_NOT_SET); 662 i = -1; 663 } 664 if (i == wb->left) { 665 wb->left = 0; 666 wb->offset += i; 667 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 668 !SSL_is_dtls(s)) 669 ssl3_release_write_buffer(s); 670 s->internal->rwstate = SSL_NOTHING; 671 return (S3I(s)->wpend_ret); 672 } else if (i <= 0) { 673 /* 674 * For DTLS, just drop it. That's kind of the 675 * whole point in using a datagram service. 676 */ 677 if (SSL_is_dtls(s)) 678 wb->left = 0; 679 return (i); 680 } 681 wb->offset += i; 682 wb->left -= i; 683 } 684 } 685 686 /* Return up to 'len' payload bytes received in 'type' records. 687 * 'type' is one of the following: 688 * 689 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 690 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 691 * - 0 (during a shutdown, no data has to be returned) 692 * 693 * If we don't have stored data to work from, read a SSL/TLS record first 694 * (possibly multiple records if we still don't have anything to return). 695 * 696 * This function must handle any surprises the peer may have for us, such as 697 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 698 * a surprise, but handled as if it were), or renegotiation requests. 699 * Also if record payloads contain fragments too small to process, we store 700 * them until there is enough for the respective protocol (the record protocol 701 * may use arbitrary fragmentation and even interleaving): 702 * Change cipher spec protocol 703 * just 1 byte needed, no need for keeping anything stored 704 * Alert protocol 705 * 2 bytes needed (AlertLevel, AlertDescription) 706 * Handshake protocol 707 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 708 * to detect unexpected Client Hello and Hello Request messages 709 * here, anything else is handled by higher layers 710 * Application data protocol 711 * none of our business 712 */ 713 int 714 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 715 { 716 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 717 int al, i, j, 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 if (s->internal->msg_callback) 917 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 918 S3I(s)->handshake_fragment, 4, s, 919 s->internal->msg_callback_arg); 920 921 if (SSL_is_init_finished(s) && 922 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 923 !S3I(s)->renegotiate) { 924 ssl3_renegotiate(s); 925 if (ssl3_renegotiate_check(s)) { 926 i = s->internal->handshake_func(s); 927 if (i < 0) 928 return (i); 929 if (i == 0) { 930 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 931 return (-1); 932 } 933 934 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 935 if (S3I(s)->rbuf.left == 0) { 936 /* no read-ahead left? */ 937 /* In the case where we try to read application data, 938 * but we trigger an SSL handshake, we return -1 with 939 * the retry option set. Otherwise renegotiation may 940 * cause nasty problems in the blocking world */ 941 ssl_force_want_read(s); 942 return (-1); 943 } 944 } 945 } 946 } 947 /* we either finished a handshake or ignored the request, 948 * now try again to obtain the (application) data we were asked for */ 949 goto start; 950 } 951 /* Disallow client initiated renegotiation if configured. */ 952 if (s->server && SSL_is_init_finished(s) && 953 S3I(s)->handshake_fragment_len >= 4 && 954 S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO && 955 (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) { 956 al = SSL_AD_NO_RENEGOTIATION; 957 goto fatal_err; 958 } 959 /* If we are a server and get a client hello when renegotiation isn't 960 * allowed send back a no renegotiation alert and carry on. 961 * WARNING: experimental code, needs reviewing (steve) 962 */ 963 if (s->server && 964 SSL_is_init_finished(s) && 965 !S3I(s)->send_connection_binding && 966 (S3I(s)->handshake_fragment_len >= 4) && 967 (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && 968 (s->session != NULL) && (s->session->cipher != NULL)) { 969 /*S3I(s)->handshake_fragment_len = 0;*/ 970 rr->length = 0; 971 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 972 goto start; 973 } 974 if (S3I(s)->alert_fragment_len >= 2) { 975 int alert_level = S3I(s)->alert_fragment[0]; 976 int alert_descr = S3I(s)->alert_fragment[1]; 977 978 S3I(s)->alert_fragment_len = 0; 979 980 if (s->internal->msg_callback) 981 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 982 S3I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 983 984 if (s->internal->info_callback != NULL) 985 cb = s->internal->info_callback; 986 else if (s->ctx->internal->info_callback != NULL) 987 cb = s->ctx->internal->info_callback; 988 989 if (cb != NULL) { 990 j = (alert_level << 8) | alert_descr; 991 cb(s, SSL_CB_READ_ALERT, j); 992 } 993 994 if (alert_level == SSL3_AL_WARNING) { 995 S3I(s)->warn_alert = alert_descr; 996 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 997 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 998 return (0); 999 } 1000 /* This is a warning but we receive it if we requested 1001 * renegotiation and the peer denied it. Terminate with 1002 * a fatal alert because if application tried to 1003 * renegotiatie it presumably had a good reason and 1004 * expects it to succeed. 1005 * 1006 * In future we might have a renegotiation where we 1007 * don't care if the peer refused it where we carry on. 1008 */ 1009 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 1010 al = SSL_AD_HANDSHAKE_FAILURE; 1011 SSLerror(s, SSL_R_NO_RENEGOTIATION); 1012 goto fatal_err; 1013 } 1014 } else if (alert_level == SSL3_AL_FATAL) { 1015 s->internal->rwstate = SSL_NOTHING; 1016 S3I(s)->fatal_alert = alert_descr; 1017 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 1018 ERR_asprintf_error_data("SSL alert number %d", 1019 alert_descr); 1020 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 1021 SSL_CTX_remove_session(s->ctx, s->session); 1022 return (0); 1023 } else { 1024 al = SSL_AD_ILLEGAL_PARAMETER; 1025 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 1026 goto fatal_err; 1027 } 1028 1029 goto start; 1030 } 1031 1032 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 1033 /* but we have not received a shutdown */ 1034 s->internal->rwstate = SSL_NOTHING; 1035 rr->length = 0; 1036 return (0); 1037 } 1038 1039 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1040 /* 'Change Cipher Spec' is just a single byte, so we know 1041 * exactly what the record payload has to look like */ 1042 if ((rr->length != 1) || (rr->off != 0) || 1043 (rr->data[0] != SSL3_MT_CCS)) { 1044 al = SSL_AD_ILLEGAL_PARAMETER; 1045 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1046 goto fatal_err; 1047 } 1048 1049 /* Check we have a cipher to change to */ 1050 if (S3I(s)->hs.cipher == NULL) { 1051 al = SSL_AD_UNEXPECTED_MESSAGE; 1052 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1053 goto fatal_err; 1054 } 1055 1056 /* Check that we should be receiving a Change Cipher Spec. */ 1057 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) { 1058 al = SSL_AD_UNEXPECTED_MESSAGE; 1059 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1060 goto fatal_err; 1061 } 1062 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 1063 1064 rr->length = 0; 1065 1066 if (s->internal->msg_callback) { 1067 s->internal->msg_callback(0, s->version, 1068 SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, 1069 s->internal->msg_callback_arg); 1070 } 1071 1072 S3I(s)->change_cipher_spec = 1; 1073 if (!ssl3_do_change_cipher_spec(s)) 1074 goto err; 1075 else 1076 goto start; 1077 } 1078 1079 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1080 if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) { 1081 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1082 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1083 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1084 s->internal->renegotiate = 1; 1085 s->internal->new_session = 1; 1086 } 1087 i = s->internal->handshake_func(s); 1088 if (i < 0) 1089 return (i); 1090 if (i == 0) { 1091 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1092 return (-1); 1093 } 1094 1095 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1096 if (S3I(s)->rbuf.left == 0) { /* no read-ahead left? */ 1097 /* In the case where we try to read application data, 1098 * but we trigger an SSL handshake, we return -1 with 1099 * the retry option set. Otherwise renegotiation may 1100 * cause nasty problems in the blocking world */ 1101 ssl_force_want_read(s); 1102 return (-1); 1103 } 1104 } 1105 goto start; 1106 } 1107 1108 switch (rr->type) { 1109 default: 1110 /* 1111 * TLS up to v1.1 just ignores unknown message types: 1112 * TLS v1.2 give an unexpected message alert. 1113 */ 1114 if (s->version >= TLS1_VERSION && 1115 s->version <= TLS1_1_VERSION) { 1116 rr->length = 0; 1117 goto start; 1118 } 1119 al = SSL_AD_UNEXPECTED_MESSAGE; 1120 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1121 goto fatal_err; 1122 case SSL3_RT_CHANGE_CIPHER_SPEC: 1123 case SSL3_RT_ALERT: 1124 case SSL3_RT_HANDSHAKE: 1125 /* we already handled all of these, with the possible exception 1126 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1127 * should not happen when type != rr->type */ 1128 al = SSL_AD_UNEXPECTED_MESSAGE; 1129 SSLerror(s, ERR_R_INTERNAL_ERROR); 1130 goto fatal_err; 1131 case SSL3_RT_APPLICATION_DATA: 1132 /* At this point, we were expecting handshake data, 1133 * but have application data. If the library was 1134 * running inside ssl3_read() (i.e. in_read_app_data 1135 * is set) and it makes sense to read application data 1136 * at this point (session renegotiation not yet started), 1137 * we will indulge it. 1138 */ 1139 if (S3I(s)->in_read_app_data && 1140 (S3I(s)->total_renegotiations != 0) && 1141 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1142 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1143 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || 1144 ((S3I(s)->hs.state & SSL_ST_ACCEPT) && 1145 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1146 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1147 S3I(s)->in_read_app_data = 2; 1148 return (-1); 1149 } else { 1150 al = SSL_AD_UNEXPECTED_MESSAGE; 1151 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1152 goto fatal_err; 1153 } 1154 } 1155 /* not reached */ 1156 1157 fatal_err: 1158 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1159 err: 1160 return (-1); 1161 } 1162 1163 int 1164 ssl3_do_change_cipher_spec(SSL *s) 1165 { 1166 if (S3I(s)->hs.tls12.key_block == NULL) { 1167 if (s->session == NULL || s->session->master_key_length == 0) { 1168 /* might happen if dtls1_read_bytes() calls this */ 1169 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1170 return (0); 1171 } 1172 1173 s->session->cipher = S3I(s)->hs.cipher; 1174 if (!tls1_setup_key_block(s)) 1175 return (0); 1176 } 1177 1178 if (!tls1_change_read_cipher_state(s)) 1179 return (0); 1180 1181 /* 1182 * We have to record the message digest at this point so we can get it 1183 * before we read the finished message. 1184 */ 1185 if (!tls12_derive_peer_finished(s)) 1186 return (0); 1187 1188 return (1); 1189 } 1190 1191 int 1192 ssl3_send_alert(SSL *s, int level, int desc) 1193 { 1194 /* If a fatal one, remove from cache */ 1195 if ((level == 2) && (s->session != NULL)) 1196 SSL_CTX_remove_session(s->ctx, s->session); 1197 1198 S3I(s)->alert_dispatch = 1; 1199 S3I(s)->send_alert[0] = level; 1200 S3I(s)->send_alert[1] = desc; 1201 if (S3I(s)->wbuf.left == 0) /* data still being written out? */ 1202 return s->method->ssl_dispatch_alert(s); 1203 1204 /* else data is still being written out, we will get written 1205 * some time in the future */ 1206 return -1; 1207 } 1208 1209 int 1210 ssl3_dispatch_alert(SSL *s) 1211 { 1212 int i, j; 1213 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1214 1215 S3I(s)->alert_dispatch = 0; 1216 i = do_ssl3_write(s, SSL3_RT_ALERT, &S3I(s)->send_alert[0], 2); 1217 if (i <= 0) { 1218 S3I(s)->alert_dispatch = 1; 1219 } else { 1220 /* Alert sent to BIO. If it is important, flush it now. 1221 * If the message does not get sent due to non-blocking IO, 1222 * we will not worry too much. */ 1223 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1224 (void)BIO_flush(s->wbio); 1225 1226 if (s->internal->msg_callback) 1227 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1228 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg); 1229 1230 if (s->internal->info_callback != NULL) 1231 cb = s->internal->info_callback; 1232 else if (s->ctx->internal->info_callback != NULL) 1233 cb = s->ctx->internal->info_callback; 1234 1235 if (cb != NULL) { 1236 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1]; 1237 cb(s, SSL_CB_WRITE_ALERT, j); 1238 } 1239 } 1240 return (i); 1241 } 1242