1 /* $OpenBSD: ssl_pkt.c,v 1.41 2021/04/25 13:15:22 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 "ssl_locl.h" 116 117 #include <openssl/buffer.h> 118 #include <openssl/evp.h> 119 120 #include "bytestring.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 * CBC countermeasures for known IV weaknesses can legitimately 435 * insert a single empty record, so we allow ourselves to read 436 * once past a single empty record without forcing want_read. 437 */ 438 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 439 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 440 return -1; 441 } 442 if (s->internal->empty_record_count > 1) { 443 ssl_force_want_read(s); 444 return -1; 445 } 446 goto again; 447 } 448 449 s->internal->empty_record_count = 0; 450 451 return (1); 452 453 fatal_err: 454 ssl3_send_alert(s, SSL3_AL_FATAL, al); 455 err: 456 return (ret); 457 } 458 459 /* Call this to write data in records of type 'type' 460 * It will return <= 0 if not all data has been sent or non-blocking IO. 461 */ 462 int 463 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 464 { 465 const unsigned char *buf = buf_; 466 unsigned int tot, n, nw; 467 int i; 468 469 if (len < 0) { 470 SSLerror(s, ERR_R_INTERNAL_ERROR); 471 return -1; 472 } 473 474 s->internal->rwstate = SSL_NOTHING; 475 tot = S3I(s)->wnum; 476 S3I(s)->wnum = 0; 477 478 if (SSL_in_init(s) && !s->internal->in_handshake) { 479 i = s->internal->handshake_func(s); 480 if (i < 0) 481 return (i); 482 if (i == 0) { 483 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 484 return -1; 485 } 486 } 487 488 if (len < tot) 489 len = tot; 490 n = (len - tot); 491 for (;;) { 492 if (n > s->max_send_fragment) 493 nw = s->max_send_fragment; 494 else 495 nw = n; 496 497 i = do_ssl3_write(s, type, &(buf[tot]), nw); 498 if (i <= 0) { 499 S3I(s)->wnum = tot; 500 return i; 501 } 502 503 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 504 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 505 /* 506 * Next chunk of data should get another prepended 507 * empty fragment in ciphersuites with known-IV 508 * weakness. 509 */ 510 S3I(s)->empty_fragment_done = 0; 511 512 return tot + i; 513 } 514 515 n -= i; 516 tot += i; 517 } 518 } 519 520 static int 521 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 522 { 523 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 524 SSL_SESSION *sess = s->session; 525 int need_empty_fragment = 0; 526 size_t align, out_len; 527 uint16_t version; 528 CBB cbb; 529 int ret; 530 531 memset(&cbb, 0, sizeof(cbb)); 532 533 if (wb->buf == NULL) 534 if (!ssl3_setup_write_buffer(s)) 535 return -1; 536 537 /* 538 * First check if there is a SSL3_BUFFER_INTERNAL still being written 539 * out. This will happen with non blocking IO. 540 */ 541 if (wb->left != 0) 542 return (ssl3_write_pending(s, type, buf, len)); 543 544 /* If we have an alert to send, let's send it. */ 545 if (S3I(s)->alert_dispatch) { 546 if ((ret = s->method->ssl_dispatch_alert(s)) <= 0) 547 return (ret); 548 /* If it went, fall through and send more stuff. */ 549 550 /* We may have released our buffer, if so get it again. */ 551 if (wb->buf == NULL) 552 if (!ssl3_setup_write_buffer(s)) 553 return -1; 554 } 555 556 if (len == 0) 557 return 0; 558 559 /* 560 * Some servers hang if initial client hello is larger than 256 561 * bytes and record version number > TLS 1.0. 562 */ 563 version = s->version; 564 if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B && 565 !s->internal->renegotiate && 566 S3I(s)->hs.our_max_tls_version > TLS1_VERSION) 567 version = TLS1_VERSION; 568 569 /* 570 * Countermeasure against known-IV weakness in CBC ciphersuites 571 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this 572 * is unnecessary for AEAD. 573 */ 574 if (sess != NULL && tls12_record_layer_write_protected(s->internal->rl)) { 575 if (S3I(s)->need_empty_fragments && 576 !S3I(s)->empty_fragment_done && 577 type == SSL3_RT_APPLICATION_DATA) 578 need_empty_fragment = 1; 579 } 580 581 /* 582 * An extra fragment would be a couple of cipher blocks, which would 583 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 584 * payload, then we can just simply pretend we have two headers. 585 */ 586 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 587 if (need_empty_fragment) 588 align += SSL3_RT_HEADER_LENGTH; 589 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 590 wb->offset = align; 591 592 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) 593 goto err; 594 595 tls12_record_layer_set_version(s->internal->rl, version); 596 597 if (need_empty_fragment) { 598 if (!tls12_record_layer_seal_record(s->internal->rl, type, 599 buf, 0, &cbb)) 600 goto err; 601 S3I(s)->empty_fragment_done = 1; 602 } 603 604 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 605 goto err; 606 607 if (!CBB_finish(&cbb, NULL, &out_len)) 608 goto err; 609 610 wb->left = out_len; 611 612 /* 613 * Memorize arguments so that ssl3_write_pending can detect 614 * bad write retries later. 615 */ 616 S3I(s)->wpend_tot = len; 617 S3I(s)->wpend_buf = buf; 618 S3I(s)->wpend_type = type; 619 S3I(s)->wpend_ret = len; 620 621 /* We now just need to write the buffer. */ 622 return ssl3_write_pending(s, type, buf, len); 623 624 err: 625 CBB_cleanup(&cbb); 626 627 return -1; 628 } 629 630 /* if S3I(s)->wbuf.left != 0, we need to call this */ 631 int 632 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 633 { 634 int i; 635 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 636 637 /* XXXX */ 638 if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) && 639 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 640 (S3I(s)->wpend_type != type)) { 641 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 642 return (-1); 643 } 644 645 for (;;) { 646 errno = 0; 647 if (s->wbio != NULL) { 648 s->internal->rwstate = SSL_WRITING; 649 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), 650 (unsigned int)wb->left); 651 } else { 652 SSLerror(s, SSL_R_BIO_NOT_SET); 653 i = -1; 654 } 655 if (i == wb->left) { 656 wb->left = 0; 657 wb->offset += i; 658 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 659 !SSL_is_dtls(s)) 660 ssl3_release_write_buffer(s); 661 s->internal->rwstate = SSL_NOTHING; 662 return (S3I(s)->wpend_ret); 663 } else if (i <= 0) { 664 /* 665 * For DTLS, just drop it. That's kind of the 666 * whole point in using a datagram service. 667 */ 668 if (SSL_is_dtls(s)) 669 wb->left = 0; 670 return (i); 671 } 672 wb->offset += i; 673 wb->left -= i; 674 } 675 } 676 677 /* Return up to 'len' payload bytes received in 'type' records. 678 * 'type' is one of the following: 679 * 680 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 681 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 682 * - 0 (during a shutdown, no data has to be returned) 683 * 684 * If we don't have stored data to work from, read a SSL/TLS record first 685 * (possibly multiple records if we still don't have anything to return). 686 * 687 * This function must handle any surprises the peer may have for us, such as 688 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 689 * a surprise, but handled as if it were), or renegotiation requests. 690 * Also if record payloads contain fragments too small to process, we store 691 * them until there is enough for the respective protocol (the record protocol 692 * may use arbitrary fragmentation and even interleaving): 693 * Change cipher spec protocol 694 * just 1 byte needed, no need for keeping anything stored 695 * Alert protocol 696 * 2 bytes needed (AlertLevel, AlertDescription) 697 * Handshake protocol 698 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 699 * to detect unexpected Client Hello and Hello Request messages 700 * here, anything else is handled by higher layers 701 * Application data protocol 702 * none of our business 703 */ 704 int 705 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 706 { 707 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 708 int al, i, j, ret, rrcount = 0; 709 unsigned int n; 710 SSL3_RECORD_INTERNAL *rr; 711 712 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 713 if (!ssl3_setup_read_buffer(s)) 714 return (-1); 715 716 if (len < 0) { 717 SSLerror(s, ERR_R_INTERNAL_ERROR); 718 return -1; 719 } 720 721 if ((type && type != SSL3_RT_APPLICATION_DATA && 722 type != SSL3_RT_HANDSHAKE) || 723 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 724 SSLerror(s, ERR_R_INTERNAL_ERROR); 725 return -1; 726 } 727 728 if ((type == SSL3_RT_HANDSHAKE) && 729 (S3I(s)->handshake_fragment_len > 0)) { 730 /* (partially) satisfy request from storage */ 731 unsigned char *src = S3I(s)->handshake_fragment; 732 unsigned char *dst = buf; 733 unsigned int k; 734 735 /* peek == 0 */ 736 n = 0; 737 while ((len > 0) && (S3I(s)->handshake_fragment_len > 0)) { 738 *dst++ = *src++; 739 len--; 740 S3I(s)->handshake_fragment_len--; 741 n++; 742 } 743 /* move any remaining fragment bytes: */ 744 for (k = 0; k < S3I(s)->handshake_fragment_len; k++) 745 S3I(s)->handshake_fragment[k] = *src++; 746 return n; 747 } 748 749 /* 750 * Now S3I(s)->handshake_fragment_len == 0 if 751 * type == SSL3_RT_HANDSHAKE. 752 */ 753 if (!s->internal->in_handshake && SSL_in_init(s)) { 754 /* type == SSL3_RT_APPLICATION_DATA */ 755 i = s->internal->handshake_func(s); 756 if (i < 0) 757 return (i); 758 if (i == 0) { 759 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 760 return (-1); 761 } 762 } 763 764 start: 765 /* 766 * Do not process more than three consecutive records, otherwise the 767 * peer can cause us to loop indefinitely. Instead, return with an 768 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 769 * processing. In the future, the total number of non-handshake and 770 * non-application data records per connection should probably also be 771 * limited... 772 */ 773 if (rrcount++ >= 3) { 774 ssl_force_want_read(s); 775 return -1; 776 } 777 778 s->internal->rwstate = SSL_NOTHING; 779 780 /* 781 * S3I(s)->rrec.type - is the type of record 782 * S3I(s)->rrec.data, - data 783 * S3I(s)->rrec.off, - offset into 'data' for next read 784 * S3I(s)->rrec.length, - number of bytes. 785 */ 786 rr = &(S3I(s)->rrec); 787 788 /* get new packet if necessary */ 789 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 790 ret = ssl3_get_record(s); 791 if (ret <= 0) 792 return (ret); 793 } 794 795 /* we now have a packet which can be read and processed */ 796 797 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 798 * reset by ssl3_get_finished */ 799 && (rr->type != SSL3_RT_HANDSHAKE)) { 800 al = SSL_AD_UNEXPECTED_MESSAGE; 801 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 802 goto fatal_err; 803 } 804 805 /* If the other end has shut down, throw anything we read away 806 * (even in 'peek' mode) */ 807 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 808 rr->length = 0; 809 s->internal->rwstate = SSL_NOTHING; 810 return (0); 811 } 812 813 814 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 815 if (type == rr->type) { 816 /* make sure that we are not getting application data when we 817 * are doing a handshake for the first time */ 818 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA && 819 !tls12_record_layer_read_protected(s->internal->rl)) { 820 al = SSL_AD_UNEXPECTED_MESSAGE; 821 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 822 goto fatal_err; 823 } 824 825 if (len <= 0) 826 return (len); 827 828 if ((unsigned int)len > rr->length) 829 n = rr->length; 830 else 831 n = (unsigned int)len; 832 833 memcpy(buf, &(rr->data[rr->off]), n); 834 if (!peek) { 835 memset(&(rr->data[rr->off]), 0, n); 836 rr->length -= n; 837 rr->off += n; 838 if (rr->length == 0) { 839 s->internal->rstate = SSL_ST_READ_HEADER; 840 rr->off = 0; 841 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 842 S3I(s)->rbuf.left == 0) 843 ssl3_release_read_buffer(s); 844 } 845 } 846 return (n); 847 } 848 849 850 /* If we get here, then type != rr->type; if we have a handshake 851 * message, then it was unexpected (Hello Request or Client Hello). */ 852 853 { 854 /* 855 * In case of record types for which we have 'fragment' 856 * storage, * fill that so that we can process the data 857 * at a fixed place. 858 */ 859 unsigned int dest_maxlen = 0; 860 unsigned char *dest = NULL; 861 unsigned int *dest_len = NULL; 862 863 if (rr->type == SSL3_RT_HANDSHAKE) { 864 dest_maxlen = sizeof S3I(s)->handshake_fragment; 865 dest = S3I(s)->handshake_fragment; 866 dest_len = &S3I(s)->handshake_fragment_len; 867 } else if (rr->type == SSL3_RT_ALERT) { 868 dest_maxlen = sizeof S3I(s)->alert_fragment; 869 dest = S3I(s)->alert_fragment; 870 dest_len = &S3I(s)->alert_fragment_len; 871 } 872 if (dest_maxlen > 0) { 873 /* available space in 'dest' */ 874 n = dest_maxlen - *dest_len; 875 if (rr->length < n) 876 n = rr->length; /* available bytes */ 877 878 /* now move 'n' bytes: */ 879 while (n-- > 0) { 880 dest[(*dest_len)++] = rr->data[rr->off++]; 881 rr->length--; 882 } 883 884 if (*dest_len < dest_maxlen) 885 goto start; /* fragment was too small */ 886 } 887 } 888 889 /* S3I(s)->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; 890 * S3I(s)->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT. 891 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 892 893 /* If we are a client, check for an incoming 'Hello Request': */ 894 if ((!s->server) && (S3I(s)->handshake_fragment_len >= 4) && 895 (S3I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 896 (s->session != NULL) && (s->session->cipher != NULL)) { 897 S3I(s)->handshake_fragment_len = 0; 898 899 if ((S3I(s)->handshake_fragment[1] != 0) || 900 (S3I(s)->handshake_fragment[2] != 0) || 901 (S3I(s)->handshake_fragment[3] != 0)) { 902 al = SSL_AD_DECODE_ERROR; 903 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 904 goto fatal_err; 905 } 906 907 if (s->internal->msg_callback) 908 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 909 S3I(s)->handshake_fragment, 4, s, 910 s->internal->msg_callback_arg); 911 912 if (SSL_is_init_finished(s) && 913 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 914 !S3I(s)->renegotiate) { 915 ssl3_renegotiate(s); 916 if (ssl3_renegotiate_check(s)) { 917 i = s->internal->handshake_func(s); 918 if (i < 0) 919 return (i); 920 if (i == 0) { 921 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 922 return (-1); 923 } 924 925 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 926 if (S3I(s)->rbuf.left == 0) { 927 /* no read-ahead left? */ 928 /* In the case where we try to read application data, 929 * but we trigger an SSL handshake, we return -1 with 930 * the retry option set. Otherwise renegotiation may 931 * cause nasty problems in the blocking world */ 932 ssl_force_want_read(s); 933 return (-1); 934 } 935 } 936 } 937 } 938 /* we either finished a handshake or ignored the request, 939 * now try again to obtain the (application) data we were asked for */ 940 goto start; 941 } 942 /* Disallow client initiated renegotiation if configured. */ 943 if (s->server && SSL_is_init_finished(s) && 944 S3I(s)->handshake_fragment_len >= 4 && 945 S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO && 946 (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) { 947 al = SSL_AD_NO_RENEGOTIATION; 948 goto fatal_err; 949 } 950 /* If we are a server and get a client hello when renegotiation isn't 951 * allowed send back a no renegotiation alert and carry on. 952 * WARNING: experimental code, needs reviewing (steve) 953 */ 954 if (s->server && 955 SSL_is_init_finished(s) && 956 !S3I(s)->send_connection_binding && 957 (S3I(s)->handshake_fragment_len >= 4) && 958 (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && 959 (s->session != NULL) && (s->session->cipher != NULL)) { 960 /*S3I(s)->handshake_fragment_len = 0;*/ 961 rr->length = 0; 962 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 963 goto start; 964 } 965 if (S3I(s)->alert_fragment_len >= 2) { 966 int alert_level = S3I(s)->alert_fragment[0]; 967 int alert_descr = S3I(s)->alert_fragment[1]; 968 969 S3I(s)->alert_fragment_len = 0; 970 971 if (s->internal->msg_callback) 972 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 973 S3I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 974 975 if (s->internal->info_callback != NULL) 976 cb = s->internal->info_callback; 977 else if (s->ctx->internal->info_callback != NULL) 978 cb = s->ctx->internal->info_callback; 979 980 if (cb != NULL) { 981 j = (alert_level << 8) | alert_descr; 982 cb(s, SSL_CB_READ_ALERT, j); 983 } 984 985 if (alert_level == SSL3_AL_WARNING) { 986 S3I(s)->warn_alert = alert_descr; 987 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 988 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 989 return (0); 990 } 991 /* This is a warning but we receive it if we requested 992 * renegotiation and the peer denied it. Terminate with 993 * a fatal alert because if application tried to 994 * renegotiatie it presumably had a good reason and 995 * expects it to succeed. 996 * 997 * In future we might have a renegotiation where we 998 * don't care if the peer refused it where we carry on. 999 */ 1000 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 1001 al = SSL_AD_HANDSHAKE_FAILURE; 1002 SSLerror(s, SSL_R_NO_RENEGOTIATION); 1003 goto fatal_err; 1004 } 1005 } else if (alert_level == SSL3_AL_FATAL) { 1006 s->internal->rwstate = SSL_NOTHING; 1007 S3I(s)->fatal_alert = alert_descr; 1008 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 1009 ERR_asprintf_error_data("SSL alert number %d", 1010 alert_descr); 1011 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 1012 SSL_CTX_remove_session(s->ctx, s->session); 1013 return (0); 1014 } else { 1015 al = SSL_AD_ILLEGAL_PARAMETER; 1016 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 1017 goto fatal_err; 1018 } 1019 1020 goto start; 1021 } 1022 1023 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 1024 /* but we have not received a shutdown */ 1025 s->internal->rwstate = SSL_NOTHING; 1026 rr->length = 0; 1027 return (0); 1028 } 1029 1030 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1031 /* 'Change Cipher Spec' is just a single byte, so we know 1032 * exactly what the record payload has to look like */ 1033 if ((rr->length != 1) || (rr->off != 0) || 1034 (rr->data[0] != SSL3_MT_CCS)) { 1035 al = SSL_AD_ILLEGAL_PARAMETER; 1036 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1037 goto fatal_err; 1038 } 1039 1040 /* Check we have a cipher to change to */ 1041 if (S3I(s)->hs.cipher == NULL) { 1042 al = SSL_AD_UNEXPECTED_MESSAGE; 1043 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1044 goto fatal_err; 1045 } 1046 1047 /* Check that we should be receiving a Change Cipher Spec. */ 1048 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) { 1049 al = SSL_AD_UNEXPECTED_MESSAGE; 1050 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1051 goto fatal_err; 1052 } 1053 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 1054 1055 rr->length = 0; 1056 1057 if (s->internal->msg_callback) { 1058 s->internal->msg_callback(0, s->version, 1059 SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, 1060 s->internal->msg_callback_arg); 1061 } 1062 1063 S3I(s)->change_cipher_spec = 1; 1064 if (!ssl3_do_change_cipher_spec(s)) 1065 goto err; 1066 else 1067 goto start; 1068 } 1069 1070 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1071 if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) { 1072 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1073 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1074 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1075 s->internal->renegotiate = 1; 1076 s->internal->new_session = 1; 1077 } 1078 i = s->internal->handshake_func(s); 1079 if (i < 0) 1080 return (i); 1081 if (i == 0) { 1082 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1083 return (-1); 1084 } 1085 1086 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1087 if (S3I(s)->rbuf.left == 0) { /* no read-ahead left? */ 1088 /* In the case where we try to read application data, 1089 * but we trigger an SSL handshake, we return -1 with 1090 * the retry option set. Otherwise renegotiation may 1091 * cause nasty problems in the blocking world */ 1092 ssl_force_want_read(s); 1093 return (-1); 1094 } 1095 } 1096 goto start; 1097 } 1098 1099 switch (rr->type) { 1100 default: 1101 /* 1102 * TLS up to v1.1 just ignores unknown message types: 1103 * TLS v1.2 give an unexpected message alert. 1104 */ 1105 if (s->version >= TLS1_VERSION && 1106 s->version <= TLS1_1_VERSION) { 1107 rr->length = 0; 1108 goto start; 1109 } 1110 al = SSL_AD_UNEXPECTED_MESSAGE; 1111 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1112 goto fatal_err; 1113 case SSL3_RT_CHANGE_CIPHER_SPEC: 1114 case SSL3_RT_ALERT: 1115 case SSL3_RT_HANDSHAKE: 1116 /* we already handled all of these, with the possible exception 1117 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1118 * should not happen when type != rr->type */ 1119 al = SSL_AD_UNEXPECTED_MESSAGE; 1120 SSLerror(s, ERR_R_INTERNAL_ERROR); 1121 goto fatal_err; 1122 case SSL3_RT_APPLICATION_DATA: 1123 /* At this point, we were expecting handshake data, 1124 * but have application data. If the library was 1125 * running inside ssl3_read() (i.e. in_read_app_data 1126 * is set) and it makes sense to read application data 1127 * at this point (session renegotiation not yet started), 1128 * we will indulge it. 1129 */ 1130 if (S3I(s)->in_read_app_data && 1131 (S3I(s)->total_renegotiations != 0) && 1132 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1133 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1134 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || 1135 ((S3I(s)->hs.state & SSL_ST_ACCEPT) && 1136 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1137 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1138 S3I(s)->in_read_app_data = 2; 1139 return (-1); 1140 } else { 1141 al = SSL_AD_UNEXPECTED_MESSAGE; 1142 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1143 goto fatal_err; 1144 } 1145 } 1146 /* not reached */ 1147 1148 fatal_err: 1149 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1150 err: 1151 return (-1); 1152 } 1153 1154 int 1155 ssl3_do_change_cipher_spec(SSL *s) 1156 { 1157 int i; 1158 1159 if (S3I(s)->hs.tls12.key_block == NULL) { 1160 if (s->session == NULL || s->session->master_key_length == 0) { 1161 /* might happen if dtls1_read_bytes() calls this */ 1162 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1163 return (0); 1164 } 1165 1166 s->session->cipher = S3I(s)->hs.cipher; 1167 if (!tls1_setup_key_block(s)) 1168 return (0); 1169 } 1170 1171 if (S3I(s)->hs.state & SSL_ST_ACCEPT) 1172 i = SSL3_CHANGE_CIPHER_SERVER_READ; 1173 else 1174 i = SSL3_CHANGE_CIPHER_CLIENT_READ; 1175 1176 if (!tls1_change_cipher_state(s, i)) 1177 return (0); 1178 1179 /* 1180 * We have to record the message digest at this point so we can get it 1181 * before we read the finished message. 1182 */ 1183 if (!tls12_derive_peer_finished(s)) 1184 return (0); 1185 1186 return (1); 1187 } 1188 1189 int 1190 ssl3_send_alert(SSL *s, int level, int desc) 1191 { 1192 /* Map tls/ssl alert value to correct one */ 1193 desc = tls1_alert_code(desc); 1194 if (desc < 0) 1195 return -1; 1196 /* If a fatal one, remove from cache */ 1197 if ((level == 2) && (s->session != NULL)) 1198 SSL_CTX_remove_session(s->ctx, s->session); 1199 1200 S3I(s)->alert_dispatch = 1; 1201 S3I(s)->send_alert[0] = level; 1202 S3I(s)->send_alert[1] = desc; 1203 if (S3I(s)->wbuf.left == 0) /* data still being written out? */ 1204 return s->method->ssl_dispatch_alert(s); 1205 1206 /* else data is still being written out, we will get written 1207 * some time in the future */ 1208 return -1; 1209 } 1210 1211 int 1212 ssl3_dispatch_alert(SSL *s) 1213 { 1214 int i, j; 1215 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1216 1217 S3I(s)->alert_dispatch = 0; 1218 i = do_ssl3_write(s, SSL3_RT_ALERT, &S3I(s)->send_alert[0], 2); 1219 if (i <= 0) { 1220 S3I(s)->alert_dispatch = 1; 1221 } else { 1222 /* Alert sent to BIO. If it is important, flush it now. 1223 * If the message does not get sent due to non-blocking IO, 1224 * we will not worry too much. */ 1225 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1226 (void)BIO_flush(s->wbio); 1227 1228 if (s->internal->msg_callback) 1229 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1230 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg); 1231 1232 if (s->internal->info_callback != NULL) 1233 cb = s->internal->info_callback; 1234 else if (s->ctx->internal->info_callback != NULL) 1235 cb = s->ctx->internal->info_callback; 1236 1237 if (cb != NULL) { 1238 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1]; 1239 cb(s, SSL_CB_WRITE_ALERT, j); 1240 } 1241 } 1242 return (i); 1243 } 1244