1 /* $OpenBSD: ssl_pkt.c,v 1.33 2020/10/14 16:57:33 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) { 231 /* ignore max parameter */ 232 max = n; 233 } else { 234 if (max < n) 235 max = n; 236 if (max > (int)(rb->len - rb->offset)) 237 max = rb->len - rb->offset; 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 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 374 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && 375 !s->internal->enc_write_ctx && !s->internal->write_hash) 376 /* Send back error using their minor version number :-) */ 377 s->version = ssl_version; 378 al = SSL_AD_PROTOCOL_VERSION; 379 goto f_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 f_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 f_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 * CBC countermeasures for known IV weaknesses can legitimately 434 * insert a single empty record, so we allow ourselves to read 435 * once past a single empty record without forcing want_read. 436 */ 437 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 438 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 439 return -1; 440 } 441 if (s->internal->empty_record_count > 1) { 442 ssl_force_want_read(s); 443 return -1; 444 } 445 goto again; 446 } 447 448 s->internal->empty_record_count = 0; 449 450 return (1); 451 452 f_err: 453 ssl3_send_alert(s, SSL3_AL_FATAL, al); 454 err: 455 return (ret); 456 } 457 458 /* Call this to write data in records of type 'type' 459 * It will return <= 0 if not all data has been sent or non-blocking IO. 460 */ 461 int 462 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 463 { 464 const unsigned char *buf = buf_; 465 unsigned int tot, n, nw; 466 int i; 467 468 if (len < 0) { 469 SSLerror(s, ERR_R_INTERNAL_ERROR); 470 return -1; 471 } 472 473 s->internal->rwstate = SSL_NOTHING; 474 tot = S3I(s)->wnum; 475 S3I(s)->wnum = 0; 476 477 if (SSL_in_init(s) && !s->internal->in_handshake) { 478 i = s->internal->handshake_func(s); 479 if (i < 0) 480 return (i); 481 if (i == 0) { 482 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 483 return -1; 484 } 485 } 486 487 if (len < tot) 488 len = tot; 489 n = (len - tot); 490 for (;;) { 491 if (n > s->max_send_fragment) 492 nw = s->max_send_fragment; 493 else 494 nw = n; 495 496 i = do_ssl3_write(s, type, &(buf[tot]), nw); 497 if (i <= 0) { 498 S3I(s)->wnum = tot; 499 return i; 500 } 501 502 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 503 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 504 /* 505 * Next chunk of data should get another prepended 506 * empty fragment in ciphersuites with known-IV 507 * weakness. 508 */ 509 S3I(s)->empty_fragment_done = 0; 510 511 return tot + i; 512 } 513 514 n -= i; 515 tot += i; 516 } 517 } 518 519 static int 520 do_ssl3_write(SSL *s, int type, const unsigned char *buf, unsigned int len) 521 { 522 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 523 SSL_SESSION *sess = s->session; 524 int need_empty_fragment = 0; 525 size_t align, out_len; 526 uint16_t version; 527 CBB cbb; 528 int ret; 529 530 memset(&cbb, 0, sizeof(cbb)); 531 532 if (wb->buf == NULL) 533 if (!ssl3_setup_write_buffer(s)) 534 return -1; 535 536 /* 537 * First check if there is a SSL3_BUFFER_INTERNAL still being written 538 * out. This will happen with non blocking IO. 539 */ 540 if (wb->left != 0) 541 return (ssl3_write_pending(s, type, buf, len)); 542 543 /* If we have an alert to send, let's send it. */ 544 if (S3I(s)->alert_dispatch) { 545 if ((ret = s->method->ssl_dispatch_alert(s)) <= 0) 546 return (ret); 547 /* If it went, fall through and send more stuff. */ 548 549 /* We may have released our buffer, if so get it again. */ 550 if (wb->buf == NULL) 551 if (!ssl3_setup_write_buffer(s)) 552 return -1; 553 } 554 555 if (len == 0) 556 return 0; 557 558 /* 559 * Some servers hang if initial client hello is larger than 256 560 * bytes and record version number > TLS 1.0. 561 */ 562 version = s->version; 563 if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B && !s->internal->renegotiate && 564 TLS1_get_version(s) > TLS1_VERSION) 565 version = TLS1_VERSION; 566 567 /* 568 * Countermeasure against known-IV weakness in CBC ciphersuites 569 * (see http://www.openssl.org/~bodo/tls-cbc.txt). Note that this 570 * is unnecessary for AEAD. 571 */ 572 if (sess != NULL && s->internal->enc_write_ctx != NULL && 573 EVP_MD_CTX_md(s->internal->write_hash) != NULL) { 574 if (S3I(s)->need_empty_fragments && 575 !S3I(s)->empty_fragment_done && 576 type == SSL3_RT_APPLICATION_DATA) 577 need_empty_fragment = 1; 578 } 579 580 /* 581 * An extra fragment would be a couple of cipher blocks, which would 582 * be a multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 583 * payload, then we can just simply pretend we have two headers. 584 */ 585 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 586 if (need_empty_fragment) 587 align += SSL3_RT_HEADER_LENGTH; 588 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 589 wb->offset = align; 590 591 if (!CBB_init_fixed(&cbb, wb->buf + align, wb->len - align)) 592 goto err; 593 594 tls12_record_layer_set_version(s->internal->rl, version); 595 596 if (need_empty_fragment) { 597 if (!tls12_record_layer_seal_record(s->internal->rl, type, 598 buf, 0, &cbb)) 599 goto err; 600 S3I(s)->empty_fragment_done = 1; 601 } 602 603 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb)) 604 goto err; 605 606 if (!CBB_finish(&cbb, NULL, &out_len)) 607 goto err; 608 609 wb->left = out_len; 610 611 /* 612 * Memorize arguments so that ssl3_write_pending can detect 613 * bad write retries later. 614 */ 615 S3I(s)->wpend_tot = len; 616 S3I(s)->wpend_buf = buf; 617 S3I(s)->wpend_type = type; 618 S3I(s)->wpend_ret = len; 619 620 /* We now just need to write the buffer. */ 621 return ssl3_write_pending(s, type, buf, len); 622 623 err: 624 CBB_cleanup(&cbb); 625 626 return -1; 627 } 628 629 /* if S3I(s)->wbuf.left != 0, we need to call this */ 630 int 631 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 632 { 633 int i; 634 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf); 635 636 /* XXXX */ 637 if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) && 638 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 639 (S3I(s)->wpend_type != type)) { 640 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 641 return (-1); 642 } 643 644 for (;;) { 645 errno = 0; 646 if (s->wbio != NULL) { 647 s->internal->rwstate = SSL_WRITING; 648 i = BIO_write(s->wbio, (char *)&(wb->buf[wb->offset]), 649 (unsigned int)wb->left); 650 } else { 651 SSLerror(s, SSL_R_BIO_NOT_SET); 652 i = -1; 653 } 654 if (i == wb->left) { 655 wb->left = 0; 656 wb->offset += i; 657 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 658 !SSL_is_dtls(s)) 659 ssl3_release_write_buffer(s); 660 s->internal->rwstate = SSL_NOTHING; 661 return (S3I(s)->wpend_ret); 662 } else if (i <= 0) { 663 /* 664 * For DTLS, just drop it. That's kind of the 665 * whole point in using a datagram service. 666 */ 667 if (SSL_is_dtls(s)) 668 wb->left = 0; 669 return (i); 670 } 671 wb->offset += i; 672 wb->left -= i; 673 } 674 } 675 676 /* Return up to 'len' payload bytes received in 'type' records. 677 * 'type' is one of the following: 678 * 679 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 680 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 681 * - 0 (during a shutdown, no data has to be returned) 682 * 683 * If we don't have stored data to work from, read a SSL/TLS record first 684 * (possibly multiple records if we still don't have anything to return). 685 * 686 * This function must handle any surprises the peer may have for us, such as 687 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 688 * a surprise, but handled as if it were), or renegotiation requests. 689 * Also if record payloads contain fragments too small to process, we store 690 * them until there is enough for the respective protocol (the record protocol 691 * may use arbitrary fragmentation and even interleaving): 692 * Change cipher spec protocol 693 * just 1 byte needed, no need for keeping anything stored 694 * Alert protocol 695 * 2 bytes needed (AlertLevel, AlertDescription) 696 * Handshake protocol 697 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 698 * to detect unexpected Client Hello and Hello Request messages 699 * here, anything else is handled by higher layers 700 * Application data protocol 701 * none of our business 702 */ 703 int 704 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 705 { 706 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 707 int al, i, j, ret, rrcount = 0; 708 unsigned int n; 709 SSL3_RECORD_INTERNAL *rr; 710 711 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 712 if (!ssl3_setup_read_buffer(s)) 713 return (-1); 714 715 if (len < 0) { 716 SSLerror(s, ERR_R_INTERNAL_ERROR); 717 return -1; 718 } 719 720 if ((type && type != SSL3_RT_APPLICATION_DATA && 721 type != SSL3_RT_HANDSHAKE) || 722 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 723 SSLerror(s, ERR_R_INTERNAL_ERROR); 724 return -1; 725 } 726 727 if ((type == SSL3_RT_HANDSHAKE) && 728 (S3I(s)->handshake_fragment_len > 0)) { 729 /* (partially) satisfy request from storage */ 730 unsigned char *src = S3I(s)->handshake_fragment; 731 unsigned char *dst = buf; 732 unsigned int k; 733 734 /* peek == 0 */ 735 n = 0; 736 while ((len > 0) && (S3I(s)->handshake_fragment_len > 0)) { 737 *dst++ = *src++; 738 len--; 739 S3I(s)->handshake_fragment_len--; 740 n++; 741 } 742 /* move any remaining fragment bytes: */ 743 for (k = 0; k < S3I(s)->handshake_fragment_len; k++) 744 S3I(s)->handshake_fragment[k] = *src++; 745 return n; 746 } 747 748 /* 749 * Now S3I(s)->handshake_fragment_len == 0 if 750 * type == SSL3_RT_HANDSHAKE. 751 */ 752 if (!s->internal->in_handshake && SSL_in_init(s)) { 753 /* type == SSL3_RT_APPLICATION_DATA */ 754 i = s->internal->handshake_func(s); 755 if (i < 0) 756 return (i); 757 if (i == 0) { 758 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 759 return (-1); 760 } 761 } 762 763 start: 764 /* 765 * Do not process more than three consecutive records, otherwise the 766 * peer can cause us to loop indefinitely. Instead, return with an 767 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 768 * processing. In the future, the total number of non-handshake and 769 * non-application data records per connection should probably also be 770 * limited... 771 */ 772 if (rrcount++ >= 3) { 773 ssl_force_want_read(s); 774 return -1; 775 } 776 777 s->internal->rwstate = SSL_NOTHING; 778 779 /* 780 * S3I(s)->rrec.type - is the type of record 781 * S3I(s)->rrec.data, - data 782 * S3I(s)->rrec.off, - offset into 'data' for next read 783 * S3I(s)->rrec.length, - number of bytes. 784 */ 785 rr = &(S3I(s)->rrec); 786 787 /* get new packet if necessary */ 788 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 789 ret = ssl3_get_record(s); 790 if (ret <= 0) 791 return (ret); 792 } 793 794 /* we now have a packet which can be read and processed */ 795 796 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 797 * reset by ssl3_get_finished */ 798 && (rr->type != SSL3_RT_HANDSHAKE)) { 799 al = SSL_AD_UNEXPECTED_MESSAGE; 800 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 801 goto f_err; 802 } 803 804 /* If the other end has shut down, throw anything we read away 805 * (even in 'peek' mode) */ 806 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 807 rr->length = 0; 808 s->internal->rwstate = SSL_NOTHING; 809 return (0); 810 } 811 812 813 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 814 if (type == rr->type) { 815 /* make sure that we are not getting application data when we 816 * are doing a handshake for the first time */ 817 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 818 (s->enc_read_ctx == NULL)) { 819 al = SSL_AD_UNEXPECTED_MESSAGE; 820 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 821 goto f_err; 822 } 823 824 if (len <= 0) 825 return (len); 826 827 if ((unsigned int)len > rr->length) 828 n = rr->length; 829 else 830 n = (unsigned int)len; 831 832 memcpy(buf, &(rr->data[rr->off]), n); 833 if (!peek) { 834 memset(&(rr->data[rr->off]), 0, n); 835 rr->length -= n; 836 rr->off += n; 837 if (rr->length == 0) { 838 s->internal->rstate = SSL_ST_READ_HEADER; 839 rr->off = 0; 840 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 841 S3I(s)->rbuf.left == 0) 842 ssl3_release_read_buffer(s); 843 } 844 } 845 return (n); 846 } 847 848 849 /* If we get here, then type != rr->type; if we have a handshake 850 * message, then it was unexpected (Hello Request or Client Hello). */ 851 852 { 853 /* 854 * In case of record types for which we have 'fragment' 855 * storage, * fill that so that we can process the data 856 * at a fixed place. 857 */ 858 unsigned int dest_maxlen = 0; 859 unsigned char *dest = NULL; 860 unsigned int *dest_len = NULL; 861 862 if (rr->type == SSL3_RT_HANDSHAKE) { 863 dest_maxlen = sizeof S3I(s)->handshake_fragment; 864 dest = S3I(s)->handshake_fragment; 865 dest_len = &S3I(s)->handshake_fragment_len; 866 } else if (rr->type == SSL3_RT_ALERT) { 867 dest_maxlen = sizeof S3I(s)->alert_fragment; 868 dest = S3I(s)->alert_fragment; 869 dest_len = &S3I(s)->alert_fragment_len; 870 } 871 if (dest_maxlen > 0) { 872 /* available space in 'dest' */ 873 n = dest_maxlen - *dest_len; 874 if (rr->length < n) 875 n = rr->length; /* available bytes */ 876 877 /* now move 'n' bytes: */ 878 while (n-- > 0) { 879 dest[(*dest_len)++] = rr->data[rr->off++]; 880 rr->length--; 881 } 882 883 if (*dest_len < dest_maxlen) 884 goto start; /* fragment was too small */ 885 } 886 } 887 888 /* S3I(s)->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; 889 * S3I(s)->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT. 890 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 891 892 /* If we are a client, check for an incoming 'Hello Request': */ 893 if ((!s->server) && (S3I(s)->handshake_fragment_len >= 4) && 894 (S3I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 895 (s->session != NULL) && (s->session->cipher != NULL)) { 896 S3I(s)->handshake_fragment_len = 0; 897 898 if ((S3I(s)->handshake_fragment[1] != 0) || 899 (S3I(s)->handshake_fragment[2] != 0) || 900 (S3I(s)->handshake_fragment[3] != 0)) { 901 al = SSL_AD_DECODE_ERROR; 902 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 903 goto f_err; 904 } 905 906 if (s->internal->msg_callback) 907 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 908 S3I(s)->handshake_fragment, 4, s, 909 s->internal->msg_callback_arg); 910 911 if (SSL_is_init_finished(s) && 912 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 913 !S3I(s)->renegotiate) { 914 ssl3_renegotiate(s); 915 if (ssl3_renegotiate_check(s)) { 916 i = s->internal->handshake_func(s); 917 if (i < 0) 918 return (i); 919 if (i == 0) { 920 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 921 return (-1); 922 } 923 924 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 925 if (S3I(s)->rbuf.left == 0) { 926 /* no read-ahead left? */ 927 /* In the case where we try to read application data, 928 * but we trigger an SSL handshake, we return -1 with 929 * the retry option set. Otherwise renegotiation may 930 * cause nasty problems in the blocking world */ 931 ssl_force_want_read(s); 932 return (-1); 933 } 934 } 935 } 936 } 937 /* we either finished a handshake or ignored the request, 938 * now try again to obtain the (application) data we were asked for */ 939 goto start; 940 } 941 /* Disallow client initiated renegotiation if configured. */ 942 if (s->server && SSL_is_init_finished(s) && 943 S3I(s)->handshake_fragment_len >= 4 && 944 S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO && 945 (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) { 946 al = SSL_AD_NO_RENEGOTIATION; 947 goto f_err; 948 } 949 /* If we are a server and get a client hello when renegotiation isn't 950 * allowed send back a no renegotiation alert and carry on. 951 * WARNING: experimental code, needs reviewing (steve) 952 */ 953 if (s->server && 954 SSL_is_init_finished(s) && 955 !S3I(s)->send_connection_binding && 956 (S3I(s)->handshake_fragment_len >= 4) && 957 (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && 958 (s->session != NULL) && (s->session->cipher != NULL)) { 959 /*S3I(s)->handshake_fragment_len = 0;*/ 960 rr->length = 0; 961 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 962 goto start; 963 } 964 if (S3I(s)->alert_fragment_len >= 2) { 965 int alert_level = S3I(s)->alert_fragment[0]; 966 int alert_descr = S3I(s)->alert_fragment[1]; 967 968 S3I(s)->alert_fragment_len = 0; 969 970 if (s->internal->msg_callback) 971 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 972 S3I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 973 974 if (s->internal->info_callback != NULL) 975 cb = s->internal->info_callback; 976 else if (s->ctx->internal->info_callback != NULL) 977 cb = s->ctx->internal->info_callback; 978 979 if (cb != NULL) { 980 j = (alert_level << 8) | alert_descr; 981 cb(s, SSL_CB_READ_ALERT, j); 982 } 983 984 if (alert_level == SSL3_AL_WARNING) { 985 S3I(s)->warn_alert = alert_descr; 986 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 987 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 988 return (0); 989 } 990 /* This is a warning but we receive it if we requested 991 * renegotiation and the peer denied it. Terminate with 992 * a fatal alert because if application tried to 993 * renegotiatie it presumably had a good reason and 994 * expects it to succeed. 995 * 996 * In future we might have a renegotiation where we 997 * don't care if the peer refused it where we carry on. 998 */ 999 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 1000 al = SSL_AD_HANDSHAKE_FAILURE; 1001 SSLerror(s, SSL_R_NO_RENEGOTIATION); 1002 goto f_err; 1003 } 1004 } else if (alert_level == SSL3_AL_FATAL) { 1005 s->internal->rwstate = SSL_NOTHING; 1006 S3I(s)->fatal_alert = alert_descr; 1007 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 1008 ERR_asprintf_error_data("SSL alert number %d", 1009 alert_descr); 1010 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 1011 SSL_CTX_remove_session(s->ctx, s->session); 1012 return (0); 1013 } else { 1014 al = SSL_AD_ILLEGAL_PARAMETER; 1015 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 1016 goto f_err; 1017 } 1018 1019 goto start; 1020 } 1021 1022 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 1023 /* but we have not received a shutdown */ 1024 s->internal->rwstate = SSL_NOTHING; 1025 rr->length = 0; 1026 return (0); 1027 } 1028 1029 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1030 /* 'Change Cipher Spec' is just a single byte, so we know 1031 * exactly what the record payload has to look like */ 1032 if ((rr->length != 1) || (rr->off != 0) || 1033 (rr->data[0] != SSL3_MT_CCS)) { 1034 al = SSL_AD_ILLEGAL_PARAMETER; 1035 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1036 goto f_err; 1037 } 1038 1039 /* Check we have a cipher to change to */ 1040 if (S3I(s)->hs.new_cipher == NULL) { 1041 al = SSL_AD_UNEXPECTED_MESSAGE; 1042 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1043 goto f_err; 1044 } 1045 1046 /* Check that we should be receiving a Change Cipher Spec. */ 1047 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) { 1048 al = SSL_AD_UNEXPECTED_MESSAGE; 1049 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1050 goto f_err; 1051 } 1052 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 1053 1054 rr->length = 0; 1055 1056 if (s->internal->msg_callback) { 1057 s->internal->msg_callback(0, s->version, 1058 SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, 1059 s->internal->msg_callback_arg); 1060 } 1061 1062 S3I(s)->change_cipher_spec = 1; 1063 if (!ssl3_do_change_cipher_spec(s)) 1064 goto err; 1065 else 1066 goto start; 1067 } 1068 1069 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1070 if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) { 1071 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1072 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1073 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1074 s->internal->renegotiate = 1; 1075 s->internal->new_session = 1; 1076 } 1077 i = s->internal->handshake_func(s); 1078 if (i < 0) 1079 return (i); 1080 if (i == 0) { 1081 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1082 return (-1); 1083 } 1084 1085 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1086 if (S3I(s)->rbuf.left == 0) { /* no read-ahead left? */ 1087 /* In the case where we try to read application data, 1088 * but we trigger an SSL handshake, we return -1 with 1089 * the retry option set. Otherwise renegotiation may 1090 * cause nasty problems in the blocking world */ 1091 ssl_force_want_read(s); 1092 return (-1); 1093 } 1094 } 1095 goto start; 1096 } 1097 1098 switch (rr->type) { 1099 default: 1100 /* 1101 * TLS up to v1.1 just ignores unknown message types: 1102 * TLS v1.2 give an unexpected message alert. 1103 */ 1104 if (s->version >= TLS1_VERSION && 1105 s->version <= TLS1_1_VERSION) { 1106 rr->length = 0; 1107 goto start; 1108 } 1109 al = SSL_AD_UNEXPECTED_MESSAGE; 1110 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1111 goto f_err; 1112 case SSL3_RT_CHANGE_CIPHER_SPEC: 1113 case SSL3_RT_ALERT: 1114 case SSL3_RT_HANDSHAKE: 1115 /* we already handled all of these, with the possible exception 1116 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1117 * should not happen when type != rr->type */ 1118 al = SSL_AD_UNEXPECTED_MESSAGE; 1119 SSLerror(s, ERR_R_INTERNAL_ERROR); 1120 goto f_err; 1121 case SSL3_RT_APPLICATION_DATA: 1122 /* At this point, we were expecting handshake data, 1123 * but have application data. If the library was 1124 * running inside ssl3_read() (i.e. in_read_app_data 1125 * is set) and it makes sense to read application data 1126 * at this point (session renegotiation not yet started), 1127 * we will indulge it. 1128 */ 1129 if (S3I(s)->in_read_app_data && 1130 (S3I(s)->total_renegotiations != 0) && 1131 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1132 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1133 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || 1134 ((S3I(s)->hs.state & SSL_ST_ACCEPT) && 1135 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1136 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1137 S3I(s)->in_read_app_data = 2; 1138 return (-1); 1139 } else { 1140 al = SSL_AD_UNEXPECTED_MESSAGE; 1141 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1142 goto f_err; 1143 } 1144 } 1145 /* not reached */ 1146 1147 f_err: 1148 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1149 err: 1150 return (-1); 1151 } 1152 1153 int 1154 ssl3_do_change_cipher_spec(SSL *s) 1155 { 1156 int i; 1157 const char *sender; 1158 int slen; 1159 1160 if (S3I(s)->hs.state & SSL_ST_ACCEPT) 1161 i = SSL3_CHANGE_CIPHER_SERVER_READ; 1162 else 1163 i = SSL3_CHANGE_CIPHER_CLIENT_READ; 1164 1165 if (S3I(s)->hs.key_block == NULL) { 1166 if (s->session == NULL || s->session->master_key_length == 0) { 1167 /* might happen if dtls1_read_bytes() calls this */ 1168 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1169 return (0); 1170 } 1171 1172 s->session->cipher = S3I(s)->hs.new_cipher; 1173 if (!tls1_setup_key_block(s)) 1174 return (0); 1175 } 1176 1177 if (!tls1_change_cipher_state(s, i)) 1178 return (0); 1179 1180 /* we have to record the message digest at 1181 * this point so we can get it before we read 1182 * the finished message */ 1183 if (S3I(s)->hs.state & SSL_ST_CONNECT) { 1184 sender = TLS_MD_SERVER_FINISH_CONST; 1185 slen = TLS_MD_SERVER_FINISH_CONST_SIZE; 1186 } else { 1187 sender = TLS_MD_CLIENT_FINISH_CONST; 1188 slen = TLS_MD_CLIENT_FINISH_CONST_SIZE; 1189 } 1190 1191 i = tls1_final_finish_mac(s, sender, slen, 1192 S3I(s)->tmp.peer_finish_md); 1193 if (i == 0) { 1194 SSLerror(s, ERR_R_INTERNAL_ERROR); 1195 return 0; 1196 } 1197 S3I(s)->tmp.peer_finish_md_len = i; 1198 1199 return (1); 1200 } 1201 1202 int 1203 ssl3_send_alert(SSL *s, int level, int desc) 1204 { 1205 /* Map tls/ssl alert value to correct one */ 1206 desc = tls1_alert_code(desc); 1207 if (desc < 0) 1208 return -1; 1209 /* If a fatal one, remove from cache */ 1210 if ((level == 2) && (s->session != NULL)) 1211 SSL_CTX_remove_session(s->ctx, s->session); 1212 1213 S3I(s)->alert_dispatch = 1; 1214 S3I(s)->send_alert[0] = level; 1215 S3I(s)->send_alert[1] = desc; 1216 if (S3I(s)->wbuf.left == 0) /* data still being written out? */ 1217 return s->method->ssl_dispatch_alert(s); 1218 1219 /* else data is still being written out, we will get written 1220 * some time in the future */ 1221 return -1; 1222 } 1223 1224 int 1225 ssl3_dispatch_alert(SSL *s) 1226 { 1227 int i, j; 1228 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1229 1230 S3I(s)->alert_dispatch = 0; 1231 i = do_ssl3_write(s, SSL3_RT_ALERT, &S3I(s)->send_alert[0], 2); 1232 if (i <= 0) { 1233 S3I(s)->alert_dispatch = 1; 1234 } else { 1235 /* Alert sent to BIO. If it is important, flush it now. 1236 * If the message does not get sent due to non-blocking IO, 1237 * we will not worry too much. */ 1238 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1239 (void)BIO_flush(s->wbio); 1240 1241 if (s->internal->msg_callback) 1242 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1243 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg); 1244 1245 if (s->internal->info_callback != NULL) 1246 cb = s->internal->info_callback; 1247 else if (s->ctx->internal->info_callback != NULL) 1248 cb = s->ctx->internal->info_callback; 1249 1250 if (cb != NULL) { 1251 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1]; 1252 cb(s, SSL_CB_WRITE_ALERT, j); 1253 } 1254 } 1255 return (i); 1256 } 1257