1 /* $OpenBSD: ssl_pkt.c,v 1.16 2019/03/19 16:53:03 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, int create_empty_fragment); 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 int i, len, left; 153 size_t align; 154 unsigned char *pkt; 155 SSL3_BUFFER *rb; 156 157 if (n <= 0) 158 return n; 159 160 rb = &(S3I(s)->rbuf); 161 if (rb->buf == NULL) 162 if (!ssl3_setup_read_buffer(s)) 163 return -1; 164 165 left = rb->left; 166 align = (size_t)rb->buf + SSL3_RT_HEADER_LENGTH; 167 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 168 169 if (!extend) { 170 /* start with empty packet ... */ 171 if (left == 0) 172 rb->offset = align; 173 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { 174 /* check if next packet length is large 175 * enough to justify payload alignment... */ 176 pkt = rb->buf + rb->offset; 177 if (pkt[0] == SSL3_RT_APPLICATION_DATA && 178 (pkt[3]<<8|pkt[4]) >= 128) { 179 /* Note that even if packet is corrupted 180 * and its length field is insane, we can 181 * only be led to wrong decision about 182 * whether memmove will occur or not. 183 * Header values has no effect on memmove 184 * arguments and therefore no buffer 185 * overrun can be triggered. */ 186 memmove(rb->buf + align, pkt, left); 187 rb->offset = align; 188 } 189 } 190 s->internal->packet = rb->buf + rb->offset; 191 s->internal->packet_length = 0; 192 /* ... now we can act as if 'extend' was set */ 193 } 194 195 /* For DTLS/UDP reads should not span multiple packets 196 * because the read operation returns the whole packet 197 * at once (as long as it fits into the buffer). */ 198 if (SSL_IS_DTLS(s)) { 199 if (left > 0 && n > left) 200 n = left; 201 } 202 203 /* if there is enough in the buffer from a previous read, take some */ 204 if (left >= n) { 205 s->internal->packet_length += n; 206 rb->left = left - n; 207 rb->offset += n; 208 return (n); 209 } 210 211 /* else we need to read more data */ 212 213 len = s->internal->packet_length; 214 pkt = rb->buf + align; 215 /* Move any available bytes to front of buffer: 216 * 'len' bytes already pointed to by 'packet', 217 * 'left' extra ones at the end */ 218 if (s->internal->packet != pkt) { 219 /* len > 0 */ 220 memmove(pkt, s->internal->packet, len + left); 221 s->internal->packet = pkt; 222 rb->offset = len + align; 223 } 224 225 if (n > (int)(rb->len - rb->offset)) { 226 /* does not happen */ 227 SSLerror(s, ERR_R_INTERNAL_ERROR); 228 return -1; 229 } 230 231 if (!s->internal->read_ahead) { 232 /* ignore max parameter */ 233 max = n; 234 } else { 235 if (max < n) 236 max = n; 237 if (max > (int)(rb->len - rb->offset)) 238 max = rb->len - rb->offset; 239 } 240 241 while (left < n) { 242 /* Now we have len+left bytes at the front of S3I(s)->rbuf.buf 243 * and need to read in more until we have len+n (up to 244 * len+max if possible) */ 245 246 errno = 0; 247 if (s->rbio != NULL) { 248 s->internal->rwstate = SSL_READING; 249 i = BIO_read(s->rbio, pkt + len + left, max - left); 250 } else { 251 SSLerror(s, SSL_R_READ_BIO_NOT_SET); 252 i = -1; 253 } 254 255 if (i <= 0) { 256 rb->left = left; 257 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 258 !SSL_IS_DTLS(s)) { 259 if (len + left == 0) 260 ssl3_release_read_buffer(s); 261 } 262 return (i); 263 } 264 left += i; 265 266 /* 267 * reads should *never* span multiple packets for DTLS because 268 * the underlying transport protocol is message oriented as 269 * opposed to byte oriented as in the TLS case. 270 */ 271 if (SSL_IS_DTLS(s)) { 272 if (n > left) 273 n = left; /* makes the while condition false */ 274 } 275 } 276 277 /* done reading, now the book-keeping */ 278 rb->offset += n; 279 rb->left = left - n; 280 s->internal->packet_length += n; 281 s->internal->rwstate = SSL_NOTHING; 282 283 return (n); 284 } 285 286 int 287 ssl3_packet_read(SSL *s, int plen) 288 { 289 int n; 290 291 n = ssl3_read_n(s, plen, S3I(s)->rbuf.len, 0); 292 if (n <= 0) 293 return n; 294 if (s->internal->packet_length < plen) 295 return s->internal->packet_length; 296 297 return plen; 298 } 299 300 int 301 ssl3_packet_extend(SSL *s, int plen) 302 { 303 int rlen, n; 304 305 if (s->internal->packet_length >= plen) 306 return plen; 307 rlen = plen - s->internal->packet_length; 308 309 n = ssl3_read_n(s, rlen, rlen, 1); 310 if (n <= 0) 311 return n; 312 if (s->internal->packet_length < plen) 313 return s->internal->packet_length; 314 315 return plen; 316 } 317 318 /* Call this to get a new input record. 319 * It will return <= 0 if more data is needed, normally due to an error 320 * or non-blocking IO. 321 * When it finishes, one packet has been decoded and can be found in 322 * ssl->s3->internal->rrec.type - is the type of record 323 * ssl->s3->internal->rrec.data, - data 324 * ssl->s3->internal->rrec.length, - number of bytes 325 */ 326 /* used only by ssl3_read_bytes */ 327 static int 328 ssl3_get_record(SSL *s) 329 { 330 int al; 331 int enc_err, n, i, ret = -1; 332 SSL3_RECORD *rr; 333 SSL_SESSION *sess; 334 unsigned char md[EVP_MAX_MD_SIZE]; 335 unsigned mac_size, orig_len; 336 337 rr = &(S3I(s)->rrec); 338 sess = s->session; 339 340 again: 341 /* check if we have the header */ 342 if ((s->internal->rstate != SSL_ST_READ_BODY) || 343 (s->internal->packet_length < SSL3_RT_HEADER_LENGTH)) { 344 CBS header; 345 uint16_t len, ssl_version; 346 uint8_t type; 347 348 n = ssl3_packet_read(s, SSL3_RT_HEADER_LENGTH); 349 if (n <= 0) 350 return (n); 351 352 s->internal->mac_packet = 1; 353 s->internal->rstate = SSL_ST_READ_BODY; 354 355 if (s->server && s->internal->first_packet) { 356 if ((ret = ssl_server_legacy_first_packet(s)) != 1) 357 return (ret); 358 ret = -1; 359 } 360 361 CBS_init(&header, s->internal->packet, SSL3_RT_HEADER_LENGTH); 362 363 /* Pull apart the header into the SSL3_RECORD */ 364 if (!CBS_get_u8(&header, &type) || 365 !CBS_get_u16(&header, &ssl_version) || 366 !CBS_get_u16(&header, &len)) { 367 SSLerror(s, SSL_R_BAD_PACKET_LENGTH); 368 goto err; 369 } 370 371 rr->type = type; 372 rr->length = len; 373 374 /* Lets check version */ 375 if (!s->internal->first_packet && ssl_version != s->version) { 376 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 377 if ((s->version & 0xFF00) == (ssl_version & 0xFF00) && 378 !s->internal->enc_write_ctx && !s->internal->write_hash) 379 /* Send back error using their minor version number :-) */ 380 s->version = ssl_version; 381 al = SSL_AD_PROTOCOL_VERSION; 382 goto f_err; 383 } 384 385 if ((ssl_version >> 8) != SSL3_VERSION_MAJOR) { 386 SSLerror(s, SSL_R_WRONG_VERSION_NUMBER); 387 goto err; 388 } 389 390 if (rr->length > S3I(s)->rbuf.len - SSL3_RT_HEADER_LENGTH) { 391 al = SSL_AD_RECORD_OVERFLOW; 392 SSLerror(s, SSL_R_PACKET_LENGTH_TOO_LONG); 393 goto f_err; 394 } 395 396 /* now s->internal->rstate == SSL_ST_READ_BODY */ 397 } 398 399 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */ 400 401 n = ssl3_packet_extend(s, SSL3_RT_HEADER_LENGTH + rr->length); 402 if (n <= 0) 403 return (n); 404 if (n != SSL3_RT_HEADER_LENGTH + rr->length) 405 return (n); 406 407 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 408 409 /* At this point, s->internal->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 410 * and we have that many bytes in s->internal->packet 411 */ 412 rr->input = &(s->internal->packet[SSL3_RT_HEADER_LENGTH]); 413 414 /* ok, we can now read from 's->internal->packet' data into 'rr' 415 * rr->input points at rr->length bytes, which 416 * need to be copied into rr->data by either 417 * the decryption or by the decompression 418 * When the data is 'copied' into the rr->data buffer, 419 * rr->input will be pointed at the new buffer */ 420 421 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ] 422 * rr->length bytes of encrypted compressed stuff. */ 423 424 /* check is not needed I believe */ 425 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) { 426 al = SSL_AD_RECORD_OVERFLOW; 427 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 428 goto f_err; 429 } 430 431 /* decrypt in place in 'rr->input' */ 432 rr->data = rr->input; 433 434 enc_err = s->method->internal->ssl3_enc->enc(s, 0); 435 /* enc_err is: 436 * 0: (in non-constant time) if the record is publically invalid. 437 * 1: if the padding is valid 438 * -1: if the padding is invalid */ 439 if (enc_err == 0) { 440 al = SSL_AD_DECRYPTION_FAILED; 441 SSLerror(s, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); 442 goto f_err; 443 } 444 445 446 /* r->length is now the compressed data plus mac */ 447 if ((sess != NULL) && (s->enc_read_ctx != NULL) && 448 (EVP_MD_CTX_md(s->read_hash) != NULL)) { 449 /* s->read_hash != NULL => mac_size != -1 */ 450 unsigned char *mac = NULL; 451 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 452 453 mac_size = EVP_MD_CTX_size(s->read_hash); 454 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 455 456 /* kludge: *_cbc_remove_padding passes padding length in rr->type */ 457 orig_len = rr->length + ((unsigned int)rr->type >> 8); 458 459 /* orig_len is the length of the record before any padding was 460 * removed. This is public information, as is the MAC in use, 461 * therefore we can safely process the record in a different 462 * amount of time if it's too short to possibly contain a MAC. 463 */ 464 if (orig_len < mac_size || 465 /* CBC records must have a padding length byte too. */ 466 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 467 orig_len < mac_size + 1)) { 468 al = SSL_AD_DECODE_ERROR; 469 SSLerror(s, SSL_R_LENGTH_TOO_SHORT); 470 goto f_err; 471 } 472 473 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 474 /* We update the length so that the TLS header bytes 475 * can be constructed correctly but we need to extract 476 * the MAC in constant time from within the record, 477 * without leaking the contents of the padding bytes. 478 * */ 479 mac = mac_tmp; 480 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 481 rr->length -= mac_size; 482 } else { 483 /* In this case there's no padding, so |orig_len| 484 * equals |rec->length| and we checked that there's 485 * enough bytes for |mac_size| above. */ 486 rr->length -= mac_size; 487 mac = &rr->data[rr->length]; 488 } 489 490 i = tls1_mac(s,md,0 /* not send */); 491 if (i < 0 || mac == NULL || 492 timingsafe_memcmp(md, mac, (size_t)mac_size) != 0) 493 enc_err = -1; 494 if (rr->length > 495 SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size) 496 enc_err = -1; 497 } 498 499 if (enc_err < 0) { 500 /* 501 * A separate 'decryption_failed' alert was introduced with 502 * TLS 1.0, SSL 3.0 only has 'bad_record_mac'. But unless a 503 * decryption failure is directly visible from the ciphertext 504 * anyway, we should not reveal which kind of error 505 * occurred -- this might become visible to an attacker 506 * (e.g. via a logfile) 507 */ 508 al = SSL_AD_BAD_RECORD_MAC; 509 SSLerror(s, SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 510 goto f_err; 511 } 512 513 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) { 514 al = SSL_AD_RECORD_OVERFLOW; 515 SSLerror(s, SSL_R_DATA_LENGTH_TOO_LONG); 516 goto f_err; 517 } 518 519 rr->off = 0; 520 /* 521 * So at this point the following is true 522 * 523 * ssl->s3->internal->rrec.type is the type of record 524 * ssl->s3->internal->rrec.length == number of bytes in record 525 * ssl->s3->internal->rrec.off == offset to first valid byte 526 * ssl->s3->internal->rrec.data == where to take bytes from, increment 527 * after use :-). 528 */ 529 530 /* we have pulled in a full packet so zero things */ 531 s->internal->packet_length = 0; 532 533 if (rr->length == 0) { 534 /* 535 * CBC countermeasures for known IV weaknesses 536 * can legitimately insert a single empty record, 537 * so we allow ourselves to read once past a single 538 * empty record without forcing want_read. 539 */ 540 if (s->internal->empty_record_count++ > SSL_MAX_EMPTY_RECORDS) { 541 SSLerror(s, SSL_R_PEER_BEHAVING_BADLY); 542 return -1; 543 } 544 if (s->internal->empty_record_count > 1) { 545 ssl_force_want_read(s); 546 return -1; 547 } 548 goto again; 549 } else { 550 s->internal->empty_record_count = 0; 551 } 552 553 return (1); 554 555 f_err: 556 ssl3_send_alert(s, SSL3_AL_FATAL, al); 557 err: 558 return (ret); 559 } 560 561 /* Call this to write data in records of type 'type' 562 * It will return <= 0 if not all data has been sent or non-blocking IO. 563 */ 564 int 565 ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 566 { 567 const unsigned char *buf = buf_; 568 unsigned int tot, n, nw; 569 int i; 570 571 if (len < 0) { 572 SSLerror(s, ERR_R_INTERNAL_ERROR); 573 return -1; 574 } 575 576 s->internal->rwstate = SSL_NOTHING; 577 tot = S3I(s)->wnum; 578 S3I(s)->wnum = 0; 579 580 if (SSL_in_init(s) && !s->internal->in_handshake) { 581 i = s->internal->handshake_func(s); 582 if (i < 0) 583 return (i); 584 if (i == 0) { 585 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 586 return -1; 587 } 588 } 589 590 if (len < tot) 591 len = tot; 592 n = (len - tot); 593 for (;;) { 594 if (n > s->max_send_fragment) 595 nw = s->max_send_fragment; 596 else 597 nw = n; 598 599 i = do_ssl3_write(s, type, &(buf[tot]), nw, 0); 600 if (i <= 0) { 601 S3I(s)->wnum = tot; 602 return i; 603 } 604 605 if ((i == (int)n) || (type == SSL3_RT_APPLICATION_DATA && 606 (s->internal->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 607 /* 608 * Next chunk of data should get another prepended 609 * empty fragment in ciphersuites with known-IV 610 * weakness. 611 */ 612 S3I(s)->empty_fragment_done = 0; 613 614 return tot + i; 615 } 616 617 n -= i; 618 tot += i; 619 } 620 } 621 622 static int 623 do_ssl3_write(SSL *s, int type, const unsigned char *buf, 624 unsigned int len, int create_empty_fragment) 625 { 626 unsigned char *p, *plen; 627 int i, mac_size, clear = 0; 628 int prefix_len = 0; 629 int eivlen; 630 size_t align; 631 SSL3_RECORD *wr; 632 SSL3_BUFFER *wb = &(S3I(s)->wbuf); 633 SSL_SESSION *sess; 634 635 if (wb->buf == NULL) 636 if (!ssl3_setup_write_buffer(s)) 637 return -1; 638 639 /* first check if there is a SSL3_BUFFER still being written 640 * out. This will happen with non blocking IO */ 641 if (wb->left != 0) 642 return (ssl3_write_pending(s, type, buf, len)); 643 644 /* If we have an alert to send, lets send it */ 645 if (S3I(s)->alert_dispatch) { 646 i = s->method->ssl_dispatch_alert(s); 647 if (i <= 0) 648 return (i); 649 /* if it went, fall through and send more stuff */ 650 /* we may have released our buffer, so get it again */ 651 if (wb->buf == NULL) 652 if (!ssl3_setup_write_buffer(s)) 653 return -1; 654 } 655 656 if (len == 0 && !create_empty_fragment) 657 return 0; 658 659 wr = &(S3I(s)->wrec); 660 sess = s->session; 661 662 if ((sess == NULL) || (s->internal->enc_write_ctx == NULL) || 663 (EVP_MD_CTX_md(s->internal->write_hash) == NULL)) { 664 clear = s->internal->enc_write_ctx ? 0 : 1; /* must be AEAD cipher */ 665 mac_size = 0; 666 } else { 667 mac_size = EVP_MD_CTX_size(s->internal->write_hash); 668 if (mac_size < 0) 669 goto err; 670 } 671 672 /* 673 * 'create_empty_fragment' is true only when this function calls 674 * itself. 675 */ 676 if (!clear && !create_empty_fragment && !S3I(s)->empty_fragment_done) { 677 /* 678 * Countermeasure against known-IV weakness in CBC ciphersuites 679 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 680 */ 681 if (S3I(s)->need_empty_fragments && 682 type == SSL3_RT_APPLICATION_DATA) { 683 /* recursive function call with 'create_empty_fragment' set; 684 * this prepares and buffers the data for an empty fragment 685 * (these 'prefix_len' bytes are sent out later 686 * together with the actual payload) */ 687 prefix_len = do_ssl3_write(s, type, buf, 0, 1); 688 if (prefix_len <= 0) 689 goto err; 690 691 if (prefix_len > 692 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) { 693 /* insufficient space */ 694 SSLerror(s, ERR_R_INTERNAL_ERROR); 695 goto err; 696 } 697 } 698 699 S3I(s)->empty_fragment_done = 1; 700 } 701 702 if (create_empty_fragment) { 703 /* extra fragment would be couple of cipher blocks, 704 * which would be multiple of SSL3_ALIGN_PAYLOAD, so 705 * if we want to align the real payload, then we can 706 * just pretent we simply have two headers. */ 707 align = (size_t)wb->buf + 2 * SSL3_RT_HEADER_LENGTH; 708 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 709 710 p = wb->buf + align; 711 wb->offset = align; 712 } else if (prefix_len) { 713 p = wb->buf + wb->offset + prefix_len; 714 } else { 715 align = (size_t)wb->buf + SSL3_RT_HEADER_LENGTH; 716 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 717 718 p = wb->buf + align; 719 wb->offset = align; 720 } 721 722 /* write the header */ 723 724 *(p++) = type&0xff; 725 wr->type = type; 726 727 *(p++) = (s->version >> 8); 728 /* Some servers hang if iniatial client hello is larger than 256 729 * bytes and record version number > TLS 1.0 730 */ 731 if (S3I(s)->hs.state == SSL3_ST_CW_CLNT_HELLO_B && !s->internal->renegotiate && 732 TLS1_get_version(s) > TLS1_VERSION) 733 *(p++) = 0x1; 734 else 735 *(p++) = s->version&0xff; 736 737 /* field where we are to write out packet length */ 738 plen = p; 739 p += 2; 740 741 /* Explicit IV length. */ 742 eivlen = 0; 743 if (s->internal->enc_write_ctx && SSL_USE_EXPLICIT_IV(s)) { 744 int mode = EVP_CIPHER_CTX_mode(s->internal->enc_write_ctx); 745 if (mode == EVP_CIPH_CBC_MODE) { 746 eivlen = EVP_CIPHER_CTX_iv_length(s->internal->enc_write_ctx); 747 if (eivlen <= 1) 748 eivlen = 0; 749 } 750 } else if (s->internal->aead_write_ctx != NULL && 751 s->internal->aead_write_ctx->variable_nonce_in_record) { 752 eivlen = s->internal->aead_write_ctx->variable_nonce_len; 753 } 754 755 /* lets setup the record stuff. */ 756 wr->data = p + eivlen; 757 wr->length = (int)len; 758 wr->input = (unsigned char *)buf; 759 760 /* we now 'read' from wr->input, wr->length bytes into wr->data */ 761 762 memcpy(wr->data, wr->input, wr->length); 763 wr->input = wr->data; 764 765 /* we should still have the output to wr->data and the input 766 * from wr->input. Length should be wr->length. 767 * wr->data still points in the wb->buf */ 768 769 if (mac_size != 0) { 770 if (tls1_mac(s, 771 &(p[wr->length + eivlen]), 1) < 0) 772 goto err; 773 wr->length += mac_size; 774 } 775 776 wr->input = p; 777 wr->data = p; 778 779 if (eivlen) { 780 /* if (RAND_pseudo_bytes(p, eivlen) <= 0) 781 goto err; 782 */ 783 wr->length += eivlen; 784 } 785 786 /* ssl3_enc can only have an error on read */ 787 s->method->internal->ssl3_enc->enc(s, 1); 788 789 /* record length after mac and block padding */ 790 s2n(wr->length, plen); 791 792 /* we should now have 793 * wr->data pointing to the encrypted data, which is 794 * wr->length long */ 795 wr->type=type; /* not needed but helps for debugging */ 796 wr->length += SSL3_RT_HEADER_LENGTH; 797 798 if (create_empty_fragment) { 799 /* we are in a recursive call; 800 * just return the length, don't write out anything here 801 */ 802 return wr->length; 803 } 804 805 /* now let's set up wb */ 806 wb->left = prefix_len + wr->length; 807 808 /* memorize arguments so that ssl3_write_pending can detect 809 * bad write retries later */ 810 S3I(s)->wpend_tot = len; 811 S3I(s)->wpend_buf = buf; 812 S3I(s)->wpend_type = type; 813 S3I(s)->wpend_ret = len; 814 815 /* we now just need to write the buffer */ 816 return ssl3_write_pending(s, type, buf, len); 817 err: 818 return -1; 819 } 820 821 /* if S3I(s)->wbuf.left != 0, we need to call this */ 822 int 823 ssl3_write_pending(SSL *s, int type, const unsigned char *buf, unsigned int len) 824 { 825 int i; 826 SSL3_BUFFER *wb = &(S3I(s)->wbuf); 827 828 /* XXXX */ 829 if ((S3I(s)->wpend_tot > (int)len) || ((S3I(s)->wpend_buf != buf) && 830 !(s->internal->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) || 831 (S3I(s)->wpend_type != type)) { 832 SSLerror(s, SSL_R_BAD_WRITE_RETRY); 833 return (-1); 834 } 835 836 for (;;) { 837 errno = 0; 838 if (s->wbio != NULL) { 839 s->internal->rwstate = SSL_WRITING; 840 i = BIO_write(s->wbio, 841 (char *)&(wb->buf[wb->offset]), 842 (unsigned int)wb->left); 843 } else { 844 SSLerror(s, SSL_R_BIO_NOT_SET); 845 i = -1; 846 } 847 if (i == wb->left) { 848 wb->left = 0; 849 wb->offset += i; 850 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 851 !SSL_IS_DTLS(s)) 852 ssl3_release_write_buffer(s); 853 s->internal->rwstate = SSL_NOTHING; 854 return (S3I(s)->wpend_ret); 855 } else if (i <= 0) { 856 /* 857 * For DTLS, just drop it. That's kind of the 858 * whole point in using a datagram service. 859 */ 860 if (SSL_IS_DTLS(s)) 861 wb->left = 0; 862 return (i); 863 } 864 wb->offset += i; 865 wb->left -= i; 866 } 867 } 868 869 /* Return up to 'len' payload bytes received in 'type' records. 870 * 'type' is one of the following: 871 * 872 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 873 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 874 * - 0 (during a shutdown, no data has to be returned) 875 * 876 * If we don't have stored data to work from, read a SSL/TLS record first 877 * (possibly multiple records if we still don't have anything to return). 878 * 879 * This function must handle any surprises the peer may have for us, such as 880 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 881 * a surprise, but handled as if it were), or renegotiation requests. 882 * Also if record payloads contain fragments too small to process, we store 883 * them until there is enough for the respective protocol (the record protocol 884 * may use arbitrary fragmentation and even interleaving): 885 * Change cipher spec protocol 886 * just 1 byte needed, no need for keeping anything stored 887 * Alert protocol 888 * 2 bytes needed (AlertLevel, AlertDescription) 889 * Handshake protocol 890 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 891 * to detect unexpected Client Hello and Hello Request messages 892 * here, anything else is handled by higher layers 893 * Application data protocol 894 * none of our business 895 */ 896 int 897 ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 898 { 899 void (*cb)(const SSL *ssl, int type2, int val) = NULL; 900 int al, i, j, ret, rrcount = 0; 901 unsigned int n; 902 SSL3_RECORD *rr; 903 904 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */ 905 if (!ssl3_setup_read_buffer(s)) 906 return (-1); 907 908 if (len < 0) { 909 SSLerror(s, ERR_R_INTERNAL_ERROR); 910 return -1; 911 } 912 913 if ((type && type != SSL3_RT_APPLICATION_DATA && 914 type != SSL3_RT_HANDSHAKE) || 915 (peek && (type != SSL3_RT_APPLICATION_DATA))) { 916 SSLerror(s, ERR_R_INTERNAL_ERROR); 917 return -1; 918 } 919 920 if ((type == SSL3_RT_HANDSHAKE) && 921 (S3I(s)->handshake_fragment_len > 0)) { 922 /* (partially) satisfy request from storage */ 923 unsigned char *src = S3I(s)->handshake_fragment; 924 unsigned char *dst = buf; 925 unsigned int k; 926 927 /* peek == 0 */ 928 n = 0; 929 while ((len > 0) && (S3I(s)->handshake_fragment_len > 0)) { 930 *dst++ = *src++; 931 len--; 932 S3I(s)->handshake_fragment_len--; 933 n++; 934 } 935 /* move any remaining fragment bytes: */ 936 for (k = 0; k < S3I(s)->handshake_fragment_len; k++) 937 S3I(s)->handshake_fragment[k] = *src++; 938 return n; 939 } 940 941 /* 942 * Now S3I(s)->handshake_fragment_len == 0 if 943 * type == SSL3_RT_HANDSHAKE. 944 */ 945 if (!s->internal->in_handshake && SSL_in_init(s)) { 946 /* type == SSL3_RT_APPLICATION_DATA */ 947 i = s->internal->handshake_func(s); 948 if (i < 0) 949 return (i); 950 if (i == 0) { 951 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 952 return (-1); 953 } 954 } 955 956 start: 957 /* 958 * Do not process more than three consecutive records, otherwise the 959 * peer can cause us to loop indefinitely. Instead, return with an 960 * SSL_ERROR_WANT_READ so the caller can choose when to handle further 961 * processing. In the future, the total number of non-handshake and 962 * non-application data records per connection should probably also be 963 * limited... 964 */ 965 if (rrcount++ >= 3) { 966 ssl_force_want_read(s); 967 return -1; 968 } 969 970 s->internal->rwstate = SSL_NOTHING; 971 972 /* 973 * S3I(s)->rrec.type - is the type of record 974 * S3I(s)->rrec.data, - data 975 * S3I(s)->rrec.off, - offset into 'data' for next read 976 * S3I(s)->rrec.length, - number of bytes. 977 */ 978 rr = &(S3I(s)->rrec); 979 980 /* get new packet if necessary */ 981 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) { 982 ret = ssl3_get_record(s); 983 if (ret <= 0) 984 return (ret); 985 } 986 987 /* we now have a packet which can be read and processed */ 988 989 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec, 990 * reset by ssl3_get_finished */ 991 && (rr->type != SSL3_RT_HANDSHAKE)) { 992 al = SSL_AD_UNEXPECTED_MESSAGE; 993 SSLerror(s, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 994 goto f_err; 995 } 996 997 /* If the other end has shut down, throw anything we read away 998 * (even in 'peek' mode) */ 999 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) { 1000 rr->length = 0; 1001 s->internal->rwstate = SSL_NOTHING; 1002 return (0); 1003 } 1004 1005 1006 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */ 1007 if (type == rr->type) { 1008 /* make sure that we are not getting application data when we 1009 * are doing a handshake for the first time */ 1010 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 1011 (s->enc_read_ctx == NULL)) { 1012 al = SSL_AD_UNEXPECTED_MESSAGE; 1013 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE); 1014 goto f_err; 1015 } 1016 1017 if (len <= 0) 1018 return (len); 1019 1020 if ((unsigned int)len > rr->length) 1021 n = rr->length; 1022 else 1023 n = (unsigned int)len; 1024 1025 memcpy(buf, &(rr->data[rr->off]), n); 1026 if (!peek) { 1027 memset(&(rr->data[rr->off]), 0, n); 1028 rr->length -= n; 1029 rr->off += n; 1030 if (rr->length == 0) { 1031 s->internal->rstate = SSL_ST_READ_HEADER; 1032 rr->off = 0; 1033 if (s->internal->mode & SSL_MODE_RELEASE_BUFFERS && 1034 S3I(s)->rbuf.left == 0) 1035 ssl3_release_read_buffer(s); 1036 } 1037 } 1038 return (n); 1039 } 1040 1041 1042 /* If we get here, then type != rr->type; if we have a handshake 1043 * message, then it was unexpected (Hello Request or Client Hello). */ 1044 1045 { 1046 /* 1047 * In case of record types for which we have 'fragment' 1048 * storage, * fill that so that we can process the data 1049 * at a fixed place. 1050 */ 1051 unsigned int dest_maxlen = 0; 1052 unsigned char *dest = NULL; 1053 unsigned int *dest_len = NULL; 1054 1055 if (rr->type == SSL3_RT_HANDSHAKE) { 1056 dest_maxlen = sizeof S3I(s)->handshake_fragment; 1057 dest = S3I(s)->handshake_fragment; 1058 dest_len = &S3I(s)->handshake_fragment_len; 1059 } else if (rr->type == SSL3_RT_ALERT) { 1060 dest_maxlen = sizeof S3I(s)->alert_fragment; 1061 dest = S3I(s)->alert_fragment; 1062 dest_len = &S3I(s)->alert_fragment_len; 1063 } 1064 if (dest_maxlen > 0) { 1065 /* available space in 'dest' */ 1066 n = dest_maxlen - *dest_len; 1067 if (rr->length < n) 1068 n = rr->length; /* available bytes */ 1069 1070 /* now move 'n' bytes: */ 1071 while (n-- > 0) { 1072 dest[(*dest_len)++] = rr->data[rr->off++]; 1073 rr->length--; 1074 } 1075 1076 if (*dest_len < dest_maxlen) 1077 goto start; /* fragment was too small */ 1078 } 1079 } 1080 1081 /* S3I(s)->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; 1082 * S3I(s)->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT. 1083 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */ 1084 1085 /* If we are a client, check for an incoming 'Hello Request': */ 1086 if ((!s->server) && (S3I(s)->handshake_fragment_len >= 4) && 1087 (S3I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1088 (s->session != NULL) && (s->session->cipher != NULL)) { 1089 S3I(s)->handshake_fragment_len = 0; 1090 1091 if ((S3I(s)->handshake_fragment[1] != 0) || 1092 (S3I(s)->handshake_fragment[2] != 0) || 1093 (S3I(s)->handshake_fragment[3] != 0)) { 1094 al = SSL_AD_DECODE_ERROR; 1095 SSLerror(s, SSL_R_BAD_HELLO_REQUEST); 1096 goto f_err; 1097 } 1098 1099 if (s->internal->msg_callback) 1100 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1101 S3I(s)->handshake_fragment, 4, s, 1102 s->internal->msg_callback_arg); 1103 1104 if (SSL_is_init_finished(s) && 1105 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1106 !S3I(s)->renegotiate) { 1107 ssl3_renegotiate(s); 1108 if (ssl3_renegotiate_check(s)) { 1109 i = s->internal->handshake_func(s); 1110 if (i < 0) 1111 return (i); 1112 if (i == 0) { 1113 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1114 return (-1); 1115 } 1116 1117 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1118 if (S3I(s)->rbuf.left == 0) { 1119 /* no read-ahead left? */ 1120 /* In the case where we try to read application data, 1121 * but we trigger an SSL handshake, we return -1 with 1122 * the retry option set. Otherwise renegotiation may 1123 * cause nasty problems in the blocking world */ 1124 ssl_force_want_read(s); 1125 return (-1); 1126 } 1127 } 1128 } 1129 } 1130 /* we either finished a handshake or ignored the request, 1131 * now try again to obtain the (application) data we were asked for */ 1132 goto start; 1133 } 1134 /* Disallow client initiated renegotiation if configured. */ 1135 if (s->server && SSL_is_init_finished(s) && 1136 S3I(s)->handshake_fragment_len >= 4 && 1137 S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO && 1138 (s->internal->options & SSL_OP_NO_CLIENT_RENEGOTIATION)) { 1139 al = SSL_AD_NO_RENEGOTIATION; 1140 goto f_err; 1141 } 1142 /* If we are a server and get a client hello when renegotiation isn't 1143 * allowed send back a no renegotiation alert and carry on. 1144 * WARNING: experimental code, needs reviewing (steve) 1145 */ 1146 if (s->server && 1147 SSL_is_init_finished(s) && 1148 !S3I(s)->send_connection_binding && 1149 (S3I(s)->handshake_fragment_len >= 4) && 1150 (S3I(s)->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && 1151 (s->session != NULL) && (s->session->cipher != NULL)) { 1152 /*S3I(s)->handshake_fragment_len = 0;*/ 1153 rr->length = 0; 1154 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 1155 goto start; 1156 } 1157 if (S3I(s)->alert_fragment_len >= 2) { 1158 int alert_level = S3I(s)->alert_fragment[0]; 1159 int alert_descr = S3I(s)->alert_fragment[1]; 1160 1161 S3I(s)->alert_fragment_len = 0; 1162 1163 if (s->internal->msg_callback) 1164 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT, 1165 S3I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg); 1166 1167 if (s->internal->info_callback != NULL) 1168 cb = s->internal->info_callback; 1169 else if (s->ctx->internal->info_callback != NULL) 1170 cb = s->ctx->internal->info_callback; 1171 1172 if (cb != NULL) { 1173 j = (alert_level << 8) | alert_descr; 1174 cb(s, SSL_CB_READ_ALERT, j); 1175 } 1176 1177 if (alert_level == SSL3_AL_WARNING) { 1178 S3I(s)->warn_alert = alert_descr; 1179 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 1180 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 1181 return (0); 1182 } 1183 /* This is a warning but we receive it if we requested 1184 * renegotiation and the peer denied it. Terminate with 1185 * a fatal alert because if application tried to 1186 * renegotiatie it presumably had a good reason and 1187 * expects it to succeed. 1188 * 1189 * In future we might have a renegotiation where we 1190 * don't care if the peer refused it where we carry on. 1191 */ 1192 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 1193 al = SSL_AD_HANDSHAKE_FAILURE; 1194 SSLerror(s, SSL_R_NO_RENEGOTIATION); 1195 goto f_err; 1196 } 1197 } else if (alert_level == SSL3_AL_FATAL) { 1198 s->internal->rwstate = SSL_NOTHING; 1199 S3I(s)->fatal_alert = alert_descr; 1200 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr); 1201 ERR_asprintf_error_data("SSL alert number %d", 1202 alert_descr); 1203 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN; 1204 SSL_CTX_remove_session(s->ctx, s->session); 1205 return (0); 1206 } else { 1207 al = SSL_AD_ILLEGAL_PARAMETER; 1208 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE); 1209 goto f_err; 1210 } 1211 1212 goto start; 1213 } 1214 1215 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) { 1216 /* but we have not received a shutdown */ 1217 s->internal->rwstate = SSL_NOTHING; 1218 rr->length = 0; 1219 return (0); 1220 } 1221 1222 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1223 /* 'Change Cipher Spec' is just a single byte, so we know 1224 * exactly what the record payload has to look like */ 1225 if ((rr->length != 1) || (rr->off != 0) || 1226 (rr->data[0] != SSL3_MT_CCS)) { 1227 al = SSL_AD_ILLEGAL_PARAMETER; 1228 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1229 goto f_err; 1230 } 1231 1232 /* Check we have a cipher to change to */ 1233 if (S3I(s)->hs.new_cipher == NULL) { 1234 al = SSL_AD_UNEXPECTED_MESSAGE; 1235 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1236 goto f_err; 1237 } 1238 1239 /* Check that we should be receiving a Change Cipher Spec. */ 1240 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) { 1241 al = SSL_AD_UNEXPECTED_MESSAGE; 1242 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1243 goto f_err; 1244 } 1245 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 1246 1247 rr->length = 0; 1248 1249 if (s->internal->msg_callback) { 1250 s->internal->msg_callback(0, s->version, 1251 SSL3_RT_CHANGE_CIPHER_SPEC, rr->data, 1, s, 1252 s->internal->msg_callback_arg); 1253 } 1254 1255 S3I(s)->change_cipher_spec = 1; 1256 if (!ssl3_do_change_cipher_spec(s)) 1257 goto err; 1258 else 1259 goto start; 1260 } 1261 1262 /* Unexpected handshake message (Client Hello, or protocol violation) */ 1263 if ((S3I(s)->handshake_fragment_len >= 4) && !s->internal->in_handshake) { 1264 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) && 1265 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1266 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1267 s->internal->renegotiate = 1; 1268 s->internal->new_session = 1; 1269 } 1270 i = s->internal->handshake_func(s); 1271 if (i < 0) 1272 return (i); 1273 if (i == 0) { 1274 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE); 1275 return (-1); 1276 } 1277 1278 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) { 1279 if (S3I(s)->rbuf.left == 0) { /* no read-ahead left? */ 1280 /* In the case where we try to read application data, 1281 * but we trigger an SSL handshake, we return -1 with 1282 * the retry option set. Otherwise renegotiation may 1283 * cause nasty problems in the blocking world */ 1284 ssl_force_want_read(s); 1285 return (-1); 1286 } 1287 } 1288 goto start; 1289 } 1290 1291 switch (rr->type) { 1292 default: 1293 /* 1294 * TLS up to v1.1 just ignores unknown message types: 1295 * TLS v1.2 give an unexpected message alert. 1296 */ 1297 if (s->version >= TLS1_VERSION && 1298 s->version <= TLS1_1_VERSION) { 1299 rr->length = 0; 1300 goto start; 1301 } 1302 al = SSL_AD_UNEXPECTED_MESSAGE; 1303 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1304 goto f_err; 1305 case SSL3_RT_CHANGE_CIPHER_SPEC: 1306 case SSL3_RT_ALERT: 1307 case SSL3_RT_HANDSHAKE: 1308 /* we already handled all of these, with the possible exception 1309 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that 1310 * should not happen when type != rr->type */ 1311 al = SSL_AD_UNEXPECTED_MESSAGE; 1312 SSLerror(s, ERR_R_INTERNAL_ERROR); 1313 goto f_err; 1314 case SSL3_RT_APPLICATION_DATA: 1315 /* At this point, we were expecting handshake data, 1316 * but have application data. If the library was 1317 * running inside ssl3_read() (i.e. in_read_app_data 1318 * is set) and it makes sense to read application data 1319 * at this point (session renegotiation not yet started), 1320 * we will indulge it. 1321 */ 1322 if (S3I(s)->in_read_app_data && 1323 (S3I(s)->total_renegotiations != 0) && 1324 (((S3I(s)->hs.state & SSL_ST_CONNECT) && 1325 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) && 1326 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || 1327 ((S3I(s)->hs.state & SSL_ST_ACCEPT) && 1328 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) && 1329 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) { 1330 S3I(s)->in_read_app_data = 2; 1331 return (-1); 1332 } else { 1333 al = SSL_AD_UNEXPECTED_MESSAGE; 1334 SSLerror(s, SSL_R_UNEXPECTED_RECORD); 1335 goto f_err; 1336 } 1337 } 1338 /* not reached */ 1339 1340 f_err: 1341 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1342 err: 1343 return (-1); 1344 } 1345 1346 int 1347 ssl3_do_change_cipher_spec(SSL *s) 1348 { 1349 int i; 1350 const char *sender; 1351 int slen; 1352 1353 if (S3I(s)->hs.state & SSL_ST_ACCEPT) 1354 i = SSL3_CHANGE_CIPHER_SERVER_READ; 1355 else 1356 i = SSL3_CHANGE_CIPHER_CLIENT_READ; 1357 1358 if (S3I(s)->hs.key_block == NULL) { 1359 if (s->session == NULL || s->session->master_key_length == 0) { 1360 /* might happen if dtls1_read_bytes() calls this */ 1361 SSLerror(s, SSL_R_CCS_RECEIVED_EARLY); 1362 return (0); 1363 } 1364 1365 s->session->cipher = S3I(s)->hs.new_cipher; 1366 if (!tls1_setup_key_block(s)) 1367 return (0); 1368 } 1369 1370 if (!tls1_change_cipher_state(s, i)) 1371 return (0); 1372 1373 /* we have to record the message digest at 1374 * this point so we can get it before we read 1375 * the finished message */ 1376 if (S3I(s)->hs.state & SSL_ST_CONNECT) { 1377 sender = TLS_MD_SERVER_FINISH_CONST; 1378 slen = TLS_MD_SERVER_FINISH_CONST_SIZE; 1379 } else { 1380 sender = TLS_MD_CLIENT_FINISH_CONST; 1381 slen = TLS_MD_CLIENT_FINISH_CONST_SIZE; 1382 } 1383 1384 i = tls1_final_finish_mac(s, sender, slen, 1385 S3I(s)->tmp.peer_finish_md); 1386 if (i == 0) { 1387 SSLerror(s, ERR_R_INTERNAL_ERROR); 1388 return 0; 1389 } 1390 S3I(s)->tmp.peer_finish_md_len = i; 1391 1392 return (1); 1393 } 1394 1395 int 1396 ssl3_send_alert(SSL *s, int level, int desc) 1397 { 1398 /* Map tls/ssl alert value to correct one */ 1399 desc = tls1_alert_code(desc); 1400 if (desc < 0) 1401 return -1; 1402 /* If a fatal one, remove from cache */ 1403 if ((level == 2) && (s->session != NULL)) 1404 SSL_CTX_remove_session(s->ctx, s->session); 1405 1406 S3I(s)->alert_dispatch = 1; 1407 S3I(s)->send_alert[0] = level; 1408 S3I(s)->send_alert[1] = desc; 1409 if (S3I(s)->wbuf.left == 0) /* data still being written out? */ 1410 return s->method->ssl_dispatch_alert(s); 1411 1412 /* else data is still being written out, we will get written 1413 * some time in the future */ 1414 return -1; 1415 } 1416 1417 int 1418 ssl3_dispatch_alert(SSL *s) 1419 { 1420 int i, j; 1421 void (*cb)(const SSL *ssl, int type, int val) = NULL; 1422 1423 S3I(s)->alert_dispatch = 0; 1424 i = do_ssl3_write(s, SSL3_RT_ALERT, &S3I(s)->send_alert[0], 2, 0); 1425 if (i <= 0) { 1426 S3I(s)->alert_dispatch = 1; 1427 } else { 1428 /* Alert sent to BIO. If it is important, flush it now. 1429 * If the message does not get sent due to non-blocking IO, 1430 * we will not worry too much. */ 1431 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL) 1432 (void)BIO_flush(s->wbio); 1433 1434 if (s->internal->msg_callback) 1435 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT, 1436 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg); 1437 1438 if (s->internal->info_callback != NULL) 1439 cb = s->internal->info_callback; 1440 else if (s->ctx->internal->info_callback != NULL) 1441 cb = s->ctx->internal->info_callback; 1442 1443 if (cb != NULL) { 1444 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1]; 1445 cb(s, SSL_CB_WRITE_ALERT, j); 1446 } 1447 } 1448 return (i); 1449 } 1450