1 /* $OpenBSD: ssl_pkt.c,v 1.65 2022/11/26 16:08:56 tb 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 <limits.h> 114 #include <stdio.h> 115 116 #include <openssl/buffer.h> 117 #include <openssl/evp.h> 118 119 #include "bytestring.h" 120 #include "dtls_local.h" 121 #include "ssl_local.h" 122 #include "tls_content.h" 123 124 static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, 125 unsigned int len); 126 static int ssl3_get_record(SSL *s); 127 128 /* 129 * Force a WANT_READ return for certain error conditions where 130 * we don't want to spin internally. 131 */ 132 void 133 ssl_force_want_read(SSL *s) 134 { 135 BIO *bio; 136 137 bio = SSL_get_rbio(s); 138 BIO_clear_retry_flags(bio); 139 BIO_set_retry_read(bio); 140 141 s->rwstate = SSL_READING; 142 } 143 144 /* 145 * If extend == 0, obtain new n-byte packet; if extend == 1, increase 146 * packet by another n bytes. 147 * The packet will be in the sub-array of s->s3->rbuf.buf specified 148 * by s->packet and s->packet_length. 149 * (If s->read_ahead is set, 'max' bytes may be stored in rbuf 150 * [plus s->packet_length bytes if extend == 1].) 151 */ 152 static int 153 ssl3_read_n(SSL *s, int n, int max, int extend) 154 { 155 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf); 156 int i, len, left; 157 size_t align; 158 unsigned char *pkt; 159 160 if (n <= 0) 161 return n; 162 163 if (rb->buf == NULL) { 164 if (!ssl3_setup_read_buffer(s)) 165 return -1; 166 } 167 if (rb->buf == NULL) 168 return -1; 169 170 left = rb->left; 171 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH; 172 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 173 174 if (!extend) { 175 /* start with empty packet ... */ 176 if (left == 0) 177 rb->offset = align; 178 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { 179 /* check if next packet length is large 180 * enough to justify payload alignment... */ 181 pkt = rb->buf + rb->offset; 182 if (pkt[0] == SSL3_RT_APPLICATION_DATA && 183 (pkt[3]<<8|pkt[4]) >= 128) { 184 /* Note that even if packet is corrupted 185 * and its length field is insane, we can 186 * only be led to wrong decision about 187 * whether memmove will occur or not. 188 * Header values has no effect on memmove 189 * arguments and therefore no buffer 190 * overrun can be triggered. */ 191 memmove(rb->buf + align, pkt, left); 192 rb->offset = align; 193 } 194 } 195 s->packet = rb->buf + rb->offset; 196 s->packet_length = 0; 197 /* ... now we can act as if 'extend' was set */ 198 } 199 200 /* For DTLS/UDP reads should not span multiple packets 201 * because the read operation returns the whole packet 202 * at once (as long as it fits into the buffer). */ 203 if (SSL_is_dtls(s)) { 204 if (left > 0 && n > left) 205 n = left; 206 } 207 208 /* if there is enough in the buffer from a previous read, take some */ 209 if (left >= n) { 210 s->packet_length += n; 211 rb->left = left - n; 212 rb->offset += n; 213 return (n); 214 } 215 216 /* else we need to read more data */ 217 218 len = s->packet_length; 219 pkt = rb->buf + align; 220 /* Move any available bytes to front of buffer: 221 * 'len' bytes already pointed to by 'packet', 222 * 'left' extra ones at the end */ 223 if (s->packet != pkt) { 224 /* len > 0 */ 225 memmove(pkt, s->packet, len + left); 226 s->packet = pkt; 227 rb->offset = len + align; 228 } 229 230 if (n > (int)(rb->len - rb->offset)) { 231 /* does not happen */ 232 SSLerror(s, ERR_R_INTERNAL_ERROR); 233 return -1; 234 } 235 236 if (s->read_ahead || SSL_is_dtls(s)) { 237 if (max < n) 238 max = n; 239 if (max > (int)(rb->len - rb->offset)) 240 max = rb->len - rb->offset; 241 } else { 242 /* ignore max parameter */ 243 max = n; 244 } 245 246 while (left < n) { 247 /* Now we have len+left bytes at the front of s->s3->rbuf.buf 248 * and need to read in more until we have len+n (up to 249 * len+max if possible) */ 250 251 errno = 0; 252 if (s->rbio != NULL) { 253 s->rwstate = SSL_READING; 254 i = BIO_read(s->rbio, pkt + len + left, max - left); 255 } else { 256 SSLerror(s, SSL_R_READ_BIO_NOT_SET); 257 i = -1; 258 } 259 260 if (i <= 0) { 261 rb->left = left; 262 if (s->mode & SSL_MODE_RELEASE_BUFFERS && 263 !SSL_is_dtls(s)) { 264 if (len + left == 0) 265 ssl3_release_read_buffer(s); 266 } 267 return (i); 268 } 269 left += i; 270 271 /* 272 * reads should *never* span multiple packets for DTLS because 273 * the underlying transport protocol is message oriented as 274 * opposed to byte oriented as in the TLS case. 275 */ 276 if (SSL_is_dtls(s)) { 277 if (n > left) 278 n = left; /* makes the while condition false */ 279 } 280 } 281 282 /* done reading, now the book-keeping */ 283 rb->offset += n; 284 rb->left = left - n; 285 s->packet_length += n; 286 s->rwstate = SSL_NOTHING; 287 288 return (n); 289 } 290 291 int 292 ssl3_packet_read(SSL *s, int plen) 293 { 294 int n; 295 296 n = ssl3_read_n(s, plen, s->s3->rbuf.len, 0); 297 if (n <= 0) 298 return n; 299 if (s->packet_length < plen) 300 return s->packet_length; 301 302 return plen; 303 } 304 305 int 306 ssl3_packet_extend(SSL *s, int plen) 307 { 308 int rlen, n; 309 310 if (s->packet_length >= plen) 311 return plen; 312 rlen = plen - s->packet_length; 313 314 n = ssl3_read_n(s, rlen, rlen, 1); 315 if (n <= 0) 316 return n; 317 if (s->packet_length < plen) 318 return s->packet_length; 319 320 return plen; 321 } 322 323 /* Call this to get a new input record. 324 * It will return <= 0 if more data is needed, normally due to an error 325 * or non-blocking IO. 326 * When it finishes, one packet has been decoded and can be found in 327 * ssl->s3->rrec.type - is the type of record 328 * ssl->s3->rrec.data, - data 329 * ssl->s3->rrec.length, - number of bytes 330 */ 331 /* used only by ssl3_read_bytes */ 332 static int 333 ssl3_get_record(SSL *s) 334 { 335 SSL3_BUFFER_INTERNAL *rb = &(s->s3->rbuf); 336 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec); 337 uint8_t alert_desc; 338 int al, n; 339 int ret = -1; 340 341 again: 342 /* check if we have the header */ 343 if ((s->rstate != SSL_ST_READ_BODY) || 344 (s->packet_length < SSL3_RT_HEADER_LENGTH)) { 345 CBS header; 346 uint16_t len, ssl_version; 347 uint8_t type; 348 349 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH); 350 if (n <= 0) 351 return (n); 352 353 s->mac_packet = 1; 354 s->rstate = SSL_ST_READ_BODY; 355 356 if (s->server && s->first_packet) { 357 if ((ret = ssl_server_legacy_first_packet(s)) != 1) 358 return (ret); 359 ret = -1; 360 } 361 362 CBS_init(&header, s->packet, SSL3_RT_HEADER_LENGTH); 363 364 /* Pull apart the header into the SSL3_RECORD_INTERNAL */ 365 if (!CBS_get_u8(&header, &type) || 366 !CBS_get_u16(&header, &ssl_version) || 367 !CBS_get_u16(&header, &len)) { 368 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 369 goto err; 370 } 371 372 rr->type = type; 373 rr->length = len; 374 375 /* Lets check version */ 376 if (!s->first_packet && ssl_version != s->version) { 377 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && 378 !tls12_record_layer_write_protected(s->rl)) { 379 /* Send back error using their minor version number :-) */ 380 s->version = ssl_version; 381 } 382 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 383 al = SSL_AD_PROTOCOL_VERSION; 384 goto fatal_err; 385 } 386 387 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) { 388 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 389 goto err; 390 } 391 392 if (rr->length > rb->len - SSL3_RT_HEADER_LENGTH) { 393 al = SSL_AD_RECORD_OVERFLOW; 394 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG); 395 goto fatal_err; 396 } 397 } 398 399 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length); 400 if (n <= 0) 401 return (n); 402 if (n != SSL3_RT_HEADER_LENGTH + rr->length) 403 return (n); 404 405 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 406 407 /* 408 * A full record has now been read from the wire, which now needs 409 * to be processed. 410 */ 411 tls12_record_layer_set_version(s->rl, s->version); 412 413 if (!tls12_record_layer_open_record(s->rl, s->packet, s->packet_length, 414 s->s3->rcontent)) { 415 tls12_record_layer_alert(s->rl, &alert_desc); 416 417 if (alert_desc == 0) 418 goto err; 419 420 if (alert_desc == SSL_AD_RECORD_OVERFLOW) 421 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 422 else if (alert_desc == SSL_AD_BAD_RECORD_MAC) 423 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 424 425 al = alert_desc; 426 goto fatal_err; 427 } 428 429 /* we have pulled in a full packet so zero things */ 430 s->packet_length = 0; 431 432 if (tls_content_remaining(s->s3->rcontent) == 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 tls_content_clear(s->s3->rcontent); 444 445 /* 446 * CBC countermeasures for known IV weaknesses can legitimately 447 * insert a single empty record, so we allow ourselves to read 448 * once past a single empty record without forcing want_read. 449 */ 450 if (s->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 451 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 452 return -1; 453 } 454 if (s->empty_record_count > 1) { 455 ssl_force_want_read(s); 456 return -1; 457 } 458 goto again; 459 } 460 461 s->empty_record_count = 0; 462 463 return (1); 464 465 fatal_err: 466 ssl3_send_alert(s, SSL3_AL_FATAL, al); 467 err: 468 return (ret); 469 } 470 471 /* Call this to write data in records of type 'type' 472 * It will return <= 0 if not all data has been sent or non-blocking IO. 473 */ 474 int 475 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 476 { 477 const unsigned char *buf = buf_; 478 unsigned int tot, n, nw; 479 int i; 480 481 if (len < 0) { 482 SSLerror(s, ERR_R_INTERNAL_ERROR); 483 return -1; 484 } 485 486 s->rwstate = SSL_NOTHING; 487 tot = s->s3->wnum; 488 s->s3->wnum = 0; 489 490 if (SSL_in_init(s) && !s->in_handshake) { 491 i = s->handshake_func(s); 492 if (i < 0) 493 return (i); 494 if (i == 0) { 495 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 496 return -1; 497 } 498 } 499 500 if (len < tot) 501 len = tot; 502 n = (len - tot); 503 for (;;) { 504 if (n > s->max_send_fragment) 505 nw = s->max_send_fragment; 506 else 507 nw = n; 508 509 i = do_ssl3_write(s, type, &(buf[tot]), nw); 510 if (i <= 0) { 511 s->s3->wnum = tot; 512 return i; 513 } 514 515 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 516 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 517 /* 518 * Next chunk of data should get another prepended 519 * empty fragment in ciphersuites with known-IV 520 * weakness. 521 */ 522 s->s3->empty_fragment_done = 0; 523 524 return tot + i; 525 } 526 527 n -= i; 528 tot += i; 529 } 530 } 531 532 static int 533 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 534 { 535 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); 536 SSL_SESSION *sess = s->session; 537 int need_empty_fragment = 0; 538 size_t align, out_len; 539 uint16_t version; 540 CBB cbb; 541 int ret; 542 543 memset(&cbb, 0, sizeof(cbb)); 544 545 if (wb->buf == NULL) 546 if (!ssl3_setup_write_buffer(s)) 547 return -1; 548 549 /* 550 * First check if there is a SSL3_BUFFER_INTERNAL still being written 551 * out. This will happen with non blocking IO. 552 */ 553 if (wb->left != 0) 554 return (ssl3_write_pending(s, type, buf, len)); 555 556 /* If we have an alert to send, let's send it. */ 557 if (s->s3->alert_dispatch) { 558 if ((ret = ssl3_dispatch_alert(s)) <= 0) 559 return (ret); 560 /* If it went, fall through and send more stuff. */ 561 562 /* We may have released our buffer, if so get it again. */ 563 if (wb->buf == NULL) 564 if (!ssl3_setup_write_buffer(s)) 565 return -1; 566 } 567 568 if (len == 0) 569 return 0; 570 571 /* 572 * Some servers hang if initial client hello is larger than 256 573 * bytes and record version number > TLS 1.0. 574 */ 575 version = s->version; 576 if (s->s3->hs.state == SSL3_ST_CW_CLNT_HELLO_B && 577 !s->renegotiate && 578 s->s3->hs.our_max_tls_version > TLS1_VERSION) 579 version = TLS1_VERSION; 580 581 /* 582 * Countermeasure against known-IV weakness in CBC ciphersuites 583 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this 584 * is unnecessary for AEAD. 585 */ 586 if (sess != NULL && tls12_record_layer_write_protected(s->rl)) { 587 if (s->s3->need_empty_fragments && 588 !s->s3->empty_fragment_done && 589 type == SSL3_RT_APPLICATION_DATA) 590 need_empty_fragment = 1; 591 } 592 593 /* 594 * An extra fragment would be a couple of cipher blocks, which would 595 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 596 * payload, then we can just simply pretend we have two headers. 597 */ 598 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 599 if (need_empty_fragment) 600 align += SSL3_RT_HEADER_LENGTH; 601 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 602 wb->offset = align; 603 604 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) 605 goto err; 606 607 tls12_record_layer_set_version(s->rl, version); 608 609 if (need_empty_fragment) { 610 if (!tls12_record_layer_seal_record(s->rl, type, 611 buf, 0, &cbb)) 612 goto err; 613 s->s3->empty_fragment_done = 1; 614 } 615 616 if (!tls12_record_layer_seal_record(s->rl, type, buf, len, &cbb)) 617 goto err; 618 619 if (!CBB_finish(&cbb, NULL, &out_len)) 620 goto err; 621 622 wb->left = out_len; 623 624 /* 625 * Memorize arguments so that ssl3_write_pending can detect 626 * bad write retries later. 627 */ 628 s->s3->wpend_tot = len; 629 s->s3->wpend_buf = buf; 630 s->s3->wpend_type = type; 631 s->s3->wpend_ret = len; 632 633 /* We now just need to write the buffer. */ 634 return ssl3_write_pending(s, type, buf, len); 635 636 err: 637 CBB_cleanup(&cbb); 638 639 return -1; 640 } 641 642 /* if s->s3->wbuf.left != 0, we need to call this */ 643 int 644 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 645 { 646 int i; 647 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf); 648 649 /* XXXX */ 650 if ((s->s3->wpend_tot > (int)len) || ((s->s3->wpend_buf != buf) && 651 !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 652 (s->s3->wpend_type != type)) { 653 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 654 return (-1); 655 } 656 657 for (;;) { 658 errno = 0; 659 if (s->wbio != NULL) { 660 s->rwstate = SSL_WRITING; 661 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), 662 (unsigned int)wb->left); 663 } else { 664 SSLerror(s, SSL_R_BIO_NOT_SET); 665 i = -1; 666 } 667 if (i == wb->left) { 668 wb->left = 0; 669 wb->offset += i; 670 if (s->mode & SSL_MODE_RELEASE_BUFFERS && 671 !SSL_is_dtls(s)) 672 ssl3_release_write_buffer(s); 673 s->rwstate = SSL_NOTHING; 674 return (s->s3->wpend_ret); 675 } else if (i <= 0) { 676 /* 677 * For DTLS, just drop it. That's kind of the 678 * whole point in using a datagram service. 679 */ 680 if (SSL_is_dtls(s)) 681 wb->left = 0; 682 return (i); 683 } 684 wb->offset += i; 685 wb->left -= i; 686 } 687 } 688 689 static ssize_t 690 ssl3_read_cb(void *buf, size_t n, void *cb_arg) 691 { 692 SSL *s = cb_arg; 693 694 return tls_content_read(s->s3->rcontent, buf, n); 695 } 696 697 #define SSL3_ALERT_LENGTH 2 698 699 int 700 ssl3_read_alert(SSL *s) 701 { 702 uint8_t alert_level, alert_descr; 703 ssize_t ret; 704 CBS cbs; 705 706 /* 707 * TLSv1.2 permits an alert to be fragmented across multiple records or 708 * for multiple alerts to be be coalesced into a single alert record. 709 * In the case of DTLS, there is no way to reassemble an alert 710 * fragmented across multiple records, hence a full alert must be 711 * available in the record. 712 */ 713 if (s->s3->alert_fragment == NULL) { 714 if ((s->s3->alert_fragment = tls_buffer_new(0)) == NULL) 715 return -1; 716 tls_buffer_set_capacity_limit(s->s3->alert_fragment, 717 SSL3_ALERT_LENGTH); 718 } 719 ret = tls_buffer_extend(s->s3->alert_fragment, SSL3_ALERT_LENGTH, 720 ssl3_read_cb, s); 721 if (ret <= 0 && ret != TLS_IO_WANT_POLLIN) 722 return -1; 723 if (ret != SSL3_ALERT_LENGTH) { 724 if (SSL_is_dtls(s)) { 725 SSLerror(s, SSL_R_BAD_LENGTH); 726 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 727 return -1; 728 } 729 return 1; 730 } 731 732 if (!tls_buffer_data(s->s3->alert_fragment, &cbs)) 733 return -1; 734 735 ssl_msg_callback_cbs(s, 0, SSL3_RT_ALERT, &cbs); 736 737 if (!CBS_get_u8(&cbs, &alert_level)) 738 return -1; 739 if (!CBS_get_u8(&cbs, &alert_descr)) 740 return -1; 741 742 tls_buffer_free(s->s3->alert_fragment); 743 s->s3->alert_fragment = NULL; 744 745 ssl_info_callback(s, SSL_CB_READ_ALERT, 746 (alert_level << 8) | alert_descr); 747 748 if (alert_level == SSL3_AL_WARNING) { 749 s->s3->warn_alert = alert_descr; 750 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 751 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 752 return 0; 753 } 754 /* We requested renegotiation and the peer rejected it. */ 755 if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 756 SSLerror(s, SSL_R_NO_RENEGOTIATION); 757 ssl3_send_alert(s, SSL3_AL_FATAL, 758 SSL_AD_HANDSHAKE_FAILURE); 759 return -1; 760 } 761 } else if (alert_level == SSL3_AL_FATAL) { 762 s->rwstate = SSL_NOTHING; 763 s->s3->fatal_alert = alert_descr; 764 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 765 ERR_asprintf_error_data("SSL alert number %d", alert_descr); 766 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 767 SSL_CTX_remove_session(s->ctx, s->session); 768 return 0; 769 } else { 770 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 771 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); 772 return -1; 773 } 774 775 return 1; 776 } 777 778 int 779 ssl3_read_change_cipher_spec(SSL *s) 780 { 781 const uint8_t ccs[1] = { SSL3_MT_CCS }; 782 783 /* 784 * 'Change Cipher Spec' is just a single byte, so we know exactly what 785 * the record payload has to look like. 786 */ 787 if (tls_content_remaining(s->s3->rcontent) != sizeof(ccs)) { 788 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 789 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 790 return -1; 791 } 792 if (!tls_content_equal(s->s3->rcontent, ccs, sizeof(ccs))) { 793 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 794 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_ILLEGAL_PARAMETER); 795 return -1; 796 } 797 798 /* XDTLS: check that epoch is consistent */ 799 800 ssl_msg_callback_cbs(s, 0, SSL3_RT_CHANGE_CIPHER_SPEC, 801 tls_content_cbs(s->s3->rcontent)); 802 803 /* Check that we have a cipher to change to. */ 804 if (s->s3->hs.cipher == NULL) { 805 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 806 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 807 return -1; 808 } 809 810 /* Check that we should be receiving a Change Cipher Spec. */ 811 if (SSL_is_dtls(s)) { 812 if (!s->d1->change_cipher_spec_ok) { 813 /* 814 * We can't process a CCS now, because previous 815 * handshake messages are still missing, so just 816 * drop it. 817 */ 818 tls_content_clear(s->s3->rcontent); 819 return 1; 820 } 821 s->d1->change_cipher_spec_ok = 0; 822 } else { 823 if ((s->s3->flags & SSL3_FLAGS_CCS_OK) == 0) { 824 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 825 ssl3_send_alert(s, SSL3_AL_FATAL, 826 SSL_AD_UNEXPECTED_MESSAGE); 827 return -1; 828 } 829 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 830 } 831 832 tls_content_clear(s->s3->rcontent); 833 834 s->s3->change_cipher_spec = 1; 835 if (!ssl3_do_change_cipher_spec(s)) 836 return -1; 837 838 return 1; 839 } 840 841 static int 842 ssl3_read_handshake_unexpected(SSL *s) 843 { 844 uint32_t hs_msg_length; 845 uint8_t hs_msg_type; 846 ssize_t ssret; 847 CBS cbs; 848 int ret; 849 850 /* 851 * We need four bytes of handshake data so we have a handshake message 852 * header - this may be in the same record or fragmented across multiple 853 * records. 854 */ 855 if (s->s3->handshake_fragment == NULL) { 856 if ((s->s3->handshake_fragment = tls_buffer_new(0)) == NULL) 857 return -1; 858 tls_buffer_set_capacity_limit(s->s3->handshake_fragment, 859 SSL3_HM_HEADER_LENGTH); 860 } 861 ssret = tls_buffer_extend(s->s3->handshake_fragment, SSL3_HM_HEADER_LENGTH, 862 ssl3_read_cb, s); 863 if (ssret <= 0 && ssret != TLS_IO_WANT_POLLIN) 864 return -1; 865 if (ssret != SSL3_HM_HEADER_LENGTH) 866 return 1; 867 868 if (s->in_handshake) { 869 SSLerror(s, ERR_R_INTERNAL_ERROR); 870 return -1; 871 } 872 873 /* 874 * This code currently deals with HelloRequest and ClientHello messages - 875 * anything else is pushed to the handshake_func. Almost all of this 876 * belongs in the client/server handshake code. 877 */ 878 879 /* Parse handshake message header. */ 880 if (!tls_buffer_data(s->s3->handshake_fragment, &cbs)) 881 return -1; 882 if (!CBS_get_u8(&cbs, &hs_msg_type)) 883 return -1; 884 if (!CBS_get_u24(&cbs, &hs_msg_length)) 885 return -1; 886 887 if (hs_msg_type == SSL3_MT_HELLO_REQUEST) { 888 /* 889 * Incoming HelloRequest messages should only be received by a 890 * client. A server may send these at any time - a client should 891 * ignore the message if received in the middle of a handshake. 892 * See RFC 5246 sections 7.4 and 7.4.1.1. 893 */ 894 if (s->server) { 895 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 896 ssl3_send_alert(s, SSL3_AL_FATAL, 897 SSL_AD_UNEXPECTED_MESSAGE); 898 return -1; 899 } 900 901 if (hs_msg_length != 0) { 902 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 903 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR); 904 return -1; 905 } 906 907 if (!tls_buffer_data(s->s3->handshake_fragment, &cbs)) 908 return -1; 909 ssl_msg_callback_cbs(s, 0, SSL3_RT_HANDSHAKE, &cbs); 910 911 tls_buffer_free(s->s3->handshake_fragment); 912 s->s3->handshake_fragment = NULL; 913 914 /* 915 * It should be impossible to hit this, but keep the safety 916 * harness for now... 917 */ 918 if (s->session == NULL || s->session->cipher == NULL) 919 return 1; 920 921 /* 922 * Ignore this message if we're currently handshaking, 923 * renegotiation is already pending or renegotiation is disabled 924 * via flags. 925 */ 926 if (!SSL_is_init_finished(s) || s->s3->renegotiate || 927 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) 928 return 1; 929 930 if (!ssl3_renegotiate(s)) 931 return 1; 932 if (!ssl3_renegotiate_check(s)) 933 return 1; 934 935 } else if (hs_msg_type == SSL3_MT_CLIENT_HELLO) { 936 /* 937 * Incoming ClientHello messages should only be received by a 938 * server. A client may send these in response to server 939 * initiated renegotiation (HelloRequest) or in order to 940 * initiate renegotiation by the client. See RFC 5246 section 941 * 7.4.1.2. 942 */ 943 if (!s->server) { 944 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 945 ssl3_send_alert(s, SSL3_AL_FATAL, 946 SSL_AD_UNEXPECTED_MESSAGE); 947 return -1; 948 } 949 950 /* 951 * A client should not be sending a ClientHello unless we're not 952 * currently handshaking. 953 */ 954 if (!SSL_is_init_finished(s)) { 955 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 956 ssl3_send_alert(s, SSL3_AL_FATAL, 957 SSL_AD_UNEXPECTED_MESSAGE); 958 return -1; 959 } 960 961 if ((s->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) { 962 ssl3_send_alert(s, SSL3_AL_FATAL, 963 SSL_AD_NO_RENEGOTIATION); 964 return -1; 965 } 966 967 if (s->session == NULL || s->session->cipher == NULL) { 968 SSLerror(s, ERR_R_INTERNAL_ERROR); 969 return -1; 970 } 971 972 /* Client requested renegotiation but it is not permitted. */ 973 if (!s->s3->send_connection_binding || 974 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) { 975 ssl3_send_alert(s, SSL3_AL_WARNING, 976 SSL_AD_NO_RENEGOTIATION); 977 return 1; 978 } 979 980 s->s3->hs.state = SSL_ST_ACCEPT; 981 s->renegotiate = 1; 982 s->new_session = 1; 983 984 } else { 985 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE); 986 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 987 return -1; 988 } 989 990 if ((ret = s->handshake_func(s)) < 0) 991 return ret; 992 if (ret == 0) { 993 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 994 return -1; 995 } 996 997 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 998 if (s->s3->rbuf.left == 0) { 999 ssl_force_want_read(s); 1000 return -1; 1001 } 1002 } 1003 1004 /* 1005 * We either finished a handshake or ignored the request, now try again 1006 * to obtain the (application) data we were asked for. 1007 */ 1008 return 1; 1009 } 1010 1011 /* Return up to 'len' payload bytes received in 'type' records. 1012 * 'type' is one of the following: 1013 * 1014 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 1015 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 1016 * - 0 (during a shutdown, no data has to be returned) 1017 * 1018 * If we don't have stored data to work from, read a SSL/TLS record first 1019 * (possibly multiple records if we still don't have anything to return). 1020 * 1021 * This function must handle any surprises the peer may have for us, such as 1022 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 1023 * a surprise, but handled as if it were), or renegotiation requests. 1024 * Also if record payloads contain fragments too small to process, we store 1025 * them until there is enough for the respective protocol (the record protocol 1026 * may use arbitrary fragmentation and even interleaving): 1027 * Change cipher spec protocol 1028 * just 1 byte needed, no need for keeping anything stored 1029 * Alert protocol 1030 * 2 bytes needed (AlertLevel, AlertDescription) 1031 * Handshake protocol 1032 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 1033 * to detect unexpected Client Hello and Hello Request messages 1034 * here, anything else is handled by higher layers 1035 * Application data protocol 1036 * none of our business 1037 */ 1038 int 1039 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 1040 { 1041 int rrcount = 0; 1042 ssize_t ssret; 1043 int ret; 1044 1045 if (s->s3->rbuf.buf == NULL) { 1046 if (!ssl3_setup_read_buffer(s)) 1047 return -1; 1048 } 1049 1050 if (s->s3->rcontent == NULL) { 1051 if ((s->s3->rcontent = tls_content_new()) == NULL) 1052 return -1; 1053 } 1054 1055 if (len < 0) { 1056 SSLerror(s, ERR_R_INTERNAL_ERROR); 1057 return -1; 1058 } 1059 1060 if (type != 0 && type != SSL3_RT_APPLICATION_DATA && 1061 type != SSL3_RT_HANDSHAKE) { 1062 SSLerror(s, ERR_R_INTERNAL_ERROR); 1063 return -1; 1064 } 1065 if (peek && type != SSL3_RT_APPLICATION_DATA) { 1066 SSLerror(s, ERR_R_INTERNAL_ERROR); 1067 return -1; 1068 } 1069 1070 if (type == SSL3_RT_HANDSHAKE && 1071 s->s3->handshake_fragment != NULL && 1072 tls_buffer_remaining(s->s3->handshake_fragment) > 0) { 1073 ssize_t ssn; 1074 1075 if ((ssn = tls_buffer_read(s->s3->handshake_fragment, buf, 1076 len)) <= 0) 1077 return -1; 1078 1079 if (tls_buffer_remaining(s->s3->handshake_fragment) == 0) { 1080 tls_buffer_free(s->s3->handshake_fragment); 1081 s->s3->handshake_fragment = NULL; 1082 } 1083 1084 return (int)ssn; 1085 } 1086 1087 if (SSL_in_init(s) && !s->in_handshake) { 1088 if ((ret = s->handshake_func(s)) < 0) 1089 return ret; 1090 if (ret == 0) { 1091 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1092 return -1; 1093 } 1094 } 1095 1096 start: 1097 /* 1098 * Do not process more than three consecutive records, otherwise the 1099 * peer can cause us to loop indefinitely. Instead, return with an 1100 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 1101 * processing. In the future, the total number of non-handshake and 1102 * non-application data records per connection should probably also be 1103 * limited... 1104 */ 1105 if (rrcount++ >= 3) { 1106 ssl_force_want_read(s); 1107 return -1; 1108 } 1109 1110 s->rwstate = SSL_NOTHING; 1111 1112 if (tls_content_remaining(s->s3->rcontent) == 0) { 1113 if ((ret = ssl3_get_record(s)) <= 0) 1114 return ret; 1115 } 1116 1117 /* We now have a packet which can be read and processed. */ 1118 1119 if (s->s3->change_cipher_spec && 1120 tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) { 1121 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 1122 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 1123 return -1; 1124 } 1125 1126 /* 1127 * If the other end has shut down, throw anything we read away (even in 1128 * 'peek' mode). 1129 */ 1130 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 1131 s->rwstate = SSL_NOTHING; 1132 tls_content_clear(s->s3->rcontent); 1133 s->s3->rrec.length = 0; 1134 return 0; 1135 } 1136 1137 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 1138 if (tls_content_type(s->s3->rcontent) == type) { 1139 /* 1140 * Make sure that we are not getting application data when we 1141 * are doing a handshake for the first time. 1142 */ 1143 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 1144 !tls12_record_layer_read_protected(s->rl)) { 1145 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 1146 ssl3_send_alert(s, SSL3_AL_FATAL, 1147 SSL_AD_UNEXPECTED_MESSAGE); 1148 return -1; 1149 } 1150 1151 if (len <= 0) 1152 return len; 1153 1154 if (peek) { 1155 ssret = tls_content_peek(s->s3->rcontent, buf, len); 1156 } else { 1157 ssret = tls_content_read(s->s3->rcontent, buf, len); 1158 } 1159 if (ssret < INT_MIN || ssret > INT_MAX) 1160 return -1; 1161 if (ssret < 0) 1162 return (int)ssret; 1163 1164 if (tls_content_remaining(s->s3->rcontent) == 0) { 1165 s->rstate = SSL_ST_READ_HEADER; 1166 1167 if (s->mode & SSL_MODE_RELEASE_BUFFERS && 1168 s->s3->rbuf.left == 0) 1169 ssl3_release_read_buffer(s); 1170 } 1171 1172 return ssret; 1173 } 1174 1175 if (tls_content_type(s->s3->rcontent) == SSL3_RT_ALERT) { 1176 if ((ret = ssl3_read_alert(s)) <= 0) 1177 return ret; 1178 goto start; 1179 } 1180 1181 if (s->shutdown & SSL_SENT_SHUTDOWN) { 1182 s->rwstate = SSL_NOTHING; 1183 tls_content_clear(s->s3->rcontent); 1184 s->s3->rrec.length = 0; 1185 return 0; 1186 } 1187 1188 if (tls_content_type(s->s3->rcontent) == SSL3_RT_APPLICATION_DATA) { 1189 /* 1190 * At this point, we were expecting handshake data, but have 1191 * application data. If the library was running inside 1192 * ssl3_read() (i.e. in_read_app_data is set) and it makes 1193 * sense to read application data at this point (session 1194 * renegotiation not yet started), we will indulge it. 1195 */ 1196 if (s->s3->in_read_app_data != 0 && 1197 s->s3->total_renegotiations != 0 && 1198 (((s->s3->hs.state & SSL_ST_CONNECT) && 1199 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1200 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || ( 1201 (s->s3->hs.state & SSL_ST_ACCEPT) && 1202 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1203 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1204 s->s3->in_read_app_data = 2; 1205 return -1; 1206 } else { 1207 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1208 ssl3_send_alert(s, SSL3_AL_FATAL, 1209 SSL_AD_UNEXPECTED_MESSAGE); 1210 return -1; 1211 } 1212 } 1213 1214 if (tls_content_type(s->s3->rcontent) == SSL3_RT_CHANGE_CIPHER_SPEC) { 1215 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0) 1216 return ret; 1217 goto start; 1218 } 1219 1220 if (tls_content_type(s->s3->rcontent) == SSL3_RT_HANDSHAKE) { 1221 if ((ret = ssl3_read_handshake_unexpected(s)) <= 0) 1222 return ret; 1223 goto start; 1224 } 1225 1226 /* 1227 * Unknown record type - TLSv1.2 sends an unexpected message alert while 1228 * earlier versions silently ignore the record. 1229 */ 1230 if (ssl_effective_tls_version(s) <= TLS1_1_VERSION) { 1231 tls_content_clear(s->s3->rcontent); 1232 goto start; 1233 } 1234 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1235 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE); 1236 return -1; 1237 } 1238 1239 int 1240 ssl3_do_change_cipher_spec(SSL *s) 1241 { 1242 if (s->s3->hs.tls12.key_block == NULL) { 1243 if (s->session == NULL || s->session->master_key_length == 0) { 1244 /* might happen if dtls1_read_bytes() calls this */ 1245 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1246 return (0); 1247 } 1248 1249 s->session->cipher = s->s3->hs.cipher; 1250 if (!tls1_setup_key_block(s)) 1251 return (0); 1252 } 1253 1254 if (!tls1_change_read_cipher_state(s)) 1255 return (0); 1256 1257 /* 1258 * We have to record the message digest at this point so we can get it 1259 * before we read the finished message. 1260 */ 1261 if (!tls12_derive_peer_finished(s)) 1262 return (0); 1263 1264 return (1); 1265 } 1266 1267 static int 1268 ssl3_write_alert(SSL *s) 1269 { 1270 if (SSL_is_dtls(s)) 1271 return do_dtls1_write(s, SSL3_RT_ALERT, s->s3->send_alert, 1272 sizeof(s->s3->send_alert)); 1273 1274 return do_ssl3_write(s, SSL3_RT_ALERT, s->s3->send_alert, 1275 sizeof(s->s3->send_alert)); 1276 } 1277 1278 int 1279 ssl3_send_alert(SSL *s, int level, int desc) 1280 { 1281 /* If alert is fatal, remove session from cache. */ 1282 if (level == SSL3_AL_FATAL) 1283 SSL_CTX_remove_session(s->ctx, s->session); 1284 1285 s->s3->alert_dispatch = 1; 1286 s->s3->send_alert[0] = level; 1287 s->s3->send_alert[1] = desc; 1288 1289 /* 1290 * If data is still being written out, the alert will be dispatched at 1291 * some point in the future. 1292 */ 1293 if (s->s3->wbuf.left != 0) 1294 return -1; 1295 1296 return ssl3_dispatch_alert(s); 1297 } 1298 1299 int 1300 ssl3_dispatch_alert(SSL *s) 1301 { 1302 int ret; 1303 1304 s->s3->alert_dispatch = 0; 1305 if ((ret = ssl3_write_alert(s)) <= 0) { 1306 s->s3->alert_dispatch = 1; 1307 return ret; 1308 } 1309 1310 /* 1311 * Alert sent to BIO. If it is important, flush it now. 1312 * If the message does not get sent due to non-blocking IO, 1313 * we will not worry too much. 1314 */ 1315 if (s->s3->send_alert[0] == SSL3_AL_FATAL) 1316 (void)BIO_flush(s->wbio); 1317 1318 ssl_msg_callback(s, 1, SSL3_RT_ALERT, s->s3->send_alert, 2); 1319 1320 ssl_info_callback(s, SSL_CB_WRITE_ALERT, 1321 (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]); 1322 1323 return ret; 1324 } 1325