s3_pkt.c revision 308204
1/* ssl/s3_pkt.c */ 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 <stdio.h> 113#include <limits.h> 114#include <errno.h> 115#define USE_SOCKETS 116#include "ssl_locl.h" 117#include <openssl/evp.h> 118#include <openssl/buffer.h> 119#include <openssl/rand.h> 120 121static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, 122 unsigned int len, int create_empty_fragment); 123static int ssl3_get_record(SSL *s); 124 125int ssl3_read_n(SSL *s, int n, int max, int extend) 126{ 127 /* 128 * If extend == 0, obtain new n-byte packet; if extend == 1, increase 129 * packet by another n bytes. The packet will be in the sub-array of 130 * s->s3->rbuf.buf specified by s->packet and s->packet_length. (If 131 * s->read_ahead is set, 'max' bytes may be stored in rbuf [plus 132 * s->packet_length bytes if extend == 1].) 133 */ 134 int i, len, left; 135 long align = 0; 136 unsigned char *pkt; 137 SSL3_BUFFER *rb; 138 139 if (n <= 0) 140 return n; 141 142 rb = &(s->s3->rbuf); 143 if (rb->buf == NULL) 144 if (!ssl3_setup_read_buffer(s)) 145 return -1; 146 147 left = rb->left; 148#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 149 align = (long)rb->buf + SSL3_RT_HEADER_LENGTH; 150 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 151#endif 152 153 if (!extend) { 154 /* start with empty packet ... */ 155 if (left == 0) 156 rb->offset = align; 157 else if (align != 0 && left >= SSL3_RT_HEADER_LENGTH) { 158 /* 159 * check if next packet length is large enough to justify payload 160 * alignment... 161 */ 162 pkt = rb->buf + rb->offset; 163 if (pkt[0] == SSL3_RT_APPLICATION_DATA 164 && (pkt[3] << 8 | pkt[4]) >= 128) { 165 /* 166 * Note that even if packet is corrupted and its length field 167 * is insane, we can only be led to wrong decision about 168 * whether memmove will occur or not. Header values has no 169 * effect on memmove arguments and therefore no buffer 170 * overrun can be triggered. 171 */ 172 memmove(rb->buf + align, pkt, left); 173 rb->offset = align; 174 } 175 } 176 s->packet = rb->buf + rb->offset; 177 s->packet_length = 0; 178 /* ... now we can act as if 'extend' was set */ 179 } 180 181 /* 182 * For DTLS/UDP reads should not span multiple packets because the read 183 * operation returns the whole packet at once (as long as it fits into 184 * the buffer). 185 */ 186 if (SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER) { 187 if (left == 0 && extend) 188 return 0; 189 if (left > 0 && n > left) 190 n = left; 191 } 192 193 /* if there is enough in the buffer from a previous read, take some */ 194 if (left >= n) { 195 s->packet_length += n; 196 rb->left = left - n; 197 rb->offset += n; 198 return (n); 199 } 200 201 /* else we need to read more data */ 202 203 len = s->packet_length; 204 pkt = rb->buf + align; 205 /* 206 * Move any available bytes to front of buffer: 'len' bytes already 207 * pointed to by 'packet', 'left' extra ones at the end 208 */ 209 if (s->packet != pkt) { /* len > 0 */ 210 memmove(pkt, s->packet, len + left); 211 s->packet = pkt; 212 rb->offset = len + align; 213 } 214 215 if (n > (int)(rb->len - rb->offset)) { /* does not happen */ 216 SSLerr(SSL_F_SSL3_READ_N, ERR_R_INTERNAL_ERROR); 217 return -1; 218 } 219 220 /* We always act like read_ahead is set for DTLS */ 221 if (!s->read_ahead && !SSL_IS_DTLS(s)) 222 /* ignore max parameter */ 223 max = n; 224 else { 225 if (max < n) 226 max = n; 227 if (max > (int)(rb->len - rb->offset)) 228 max = rb->len - rb->offset; 229 } 230 231 while (left < n) { 232 /* 233 * Now we have len+left bytes at the front of s->s3->rbuf.buf and 234 * need to read in more until we have len+n (up to len+max if 235 * possible) 236 */ 237 238 clear_sys_error(); 239 if (s->rbio != NULL) { 240 s->rwstate = SSL_READING; 241 i = BIO_read(s->rbio, pkt + len + left, max - left); 242 } else { 243 SSLerr(SSL_F_SSL3_READ_N, SSL_R_READ_BIO_NOT_SET); 244 i = -1; 245 } 246 247 if (i <= 0) { 248 rb->left = left; 249 if (s->mode & SSL_MODE_RELEASE_BUFFERS && 250 SSL_version(s) != DTLS1_VERSION 251 && SSL_version(s) != DTLS1_BAD_VER) 252 if (len + left == 0) 253 ssl3_release_read_buffer(s); 254 return (i); 255 } 256 left += i; 257 /* 258 * reads should *never* span multiple packets for DTLS because the 259 * underlying transport protocol is message oriented as opposed to 260 * byte oriented as in the TLS case. 261 */ 262 if (SSL_version(s) == DTLS1_VERSION 263 || SSL_version(s) == DTLS1_BAD_VER) { 264 if (n > left) 265 n = left; /* makes the while condition false */ 266 } 267 } 268 269 /* done reading, now the book-keeping */ 270 rb->offset += n; 271 rb->left = left - n; 272 s->packet_length += n; 273 s->rwstate = SSL_NOTHING; 274 return (n); 275} 276 277/* 278 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that 279 * will be processed per call to ssl3_get_record. Without this limit an 280 * attacker could send empty records at a faster rate than we can process and 281 * cause ssl3_get_record to loop forever. 282 */ 283#define MAX_EMPTY_RECORDS 32 284 285/*- 286 * Call this to get a new input record. 287 * It will return <= 0 if more data is needed, normally due to an error 288 * or non-blocking IO. 289 * When it finishes, one packet has been decoded and can be found in 290 * ssl->s3->rrec.type - is the type of record 291 * ssl->s3->rrec.data, - data 292 * ssl->s3->rrec.length, - number of bytes 293 */ 294/* used only by ssl3_read_bytes */ 295static int ssl3_get_record(SSL *s) 296{ 297 int ssl_major, ssl_minor, al; 298 int enc_err, n, i, ret = -1; 299 SSL3_RECORD *rr; 300 SSL_SESSION *sess; 301 unsigned char *p; 302 unsigned char md[EVP_MAX_MD_SIZE]; 303 short version; 304 unsigned mac_size, orig_len; 305 size_t extra; 306 unsigned empty_record_count = 0; 307 308 rr = &(s->s3->rrec); 309 sess = s->session; 310 311 if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER) 312 extra = SSL3_RT_MAX_EXTRA; 313 else 314 extra = 0; 315 if (extra && !s->s3->init_extra) { 316 /* 317 * An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER set after 318 * ssl3_setup_buffers() was done 319 */ 320 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR); 321 return -1; 322 } 323 324 again: 325 /* check if we have the header */ 326 if ((s->rstate != SSL_ST_READ_BODY) || 327 (s->packet_length < SSL3_RT_HEADER_LENGTH)) { 328 n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH, s->s3->rbuf.len, 0); 329 if (n <= 0) 330 return (n); /* error or non-blocking */ 331 s->rstate = SSL_ST_READ_BODY; 332 333 p = s->packet; 334 335 /* Pull apart the header into the SSL3_RECORD */ 336 rr->type = *(p++); 337 ssl_major = *(p++); 338 ssl_minor = *(p++); 339 version = (ssl_major << 8) | ssl_minor; 340 n2s(p, rr->length); 341#if 0 342 fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length); 343#endif 344 345 /* Lets check version */ 346 if (!s->first_packet) { 347 if (version != s->version) { 348 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER); 349 if ((s->version & 0xFF00) == (version & 0xFF00) 350 && !s->enc_write_ctx && !s->write_hash) { 351 if (rr->type == SSL3_RT_ALERT) { 352 /* 353 * The record is using an incorrect version number, but 354 * what we've got appears to be an alert. We haven't 355 * read the body yet to check whether its a fatal or 356 * not - but chances are it is. We probably shouldn't 357 * send a fatal alert back. We'll just end. 358 */ 359 goto err; 360 } 361 /* 362 * Send back error using their minor version number :-) 363 */ 364 s->version = (unsigned short)version; 365 } 366 al = SSL_AD_PROTOCOL_VERSION; 367 goto f_err; 368 } 369 } 370 371 if ((version >> 8) != SSL3_VERSION_MAJOR) { 372 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER); 373 goto err; 374 } 375 376 if (rr->length > s->s3->rbuf.len - SSL3_RT_HEADER_LENGTH) { 377 al = SSL_AD_RECORD_OVERFLOW; 378 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG); 379 goto f_err; 380 } 381 382 /* now s->rstate == SSL_ST_READ_BODY */ 383 } 384 385 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */ 386 387 if (rr->length > s->packet_length - SSL3_RT_HEADER_LENGTH) { 388 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */ 389 i = rr->length; 390 n = ssl3_read_n(s, i, i, 1); 391 if (n <= 0) 392 return (n); /* error or non-blocking io */ 393 /* 394 * now n == rr->length, and s->packet_length == SSL3_RT_HEADER_LENGTH 395 * + rr->length 396 */ 397 } 398 399 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */ 400 401 /* 402 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length, 403 * and we have that many bytes in s->packet 404 */ 405 rr->input = &(s->packet[SSL3_RT_HEADER_LENGTH]); 406 407 /* 408 * ok, we can now read from 's->packet' data into 'rr' rr->input points 409 * at rr->length bytes, which need to be copied into rr->data by either 410 * the decryption or by the decompression When the data is 'copied' into 411 * the rr->data buffer, rr->input will be pointed at the new buffer 412 */ 413 414 /* 415 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length 416 * bytes of encrypted compressed stuff. 417 */ 418 419 /* check is not needed I believe */ 420 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH + extra) { 421 al = SSL_AD_RECORD_OVERFLOW; 422 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG); 423 goto f_err; 424 } 425 426 /* decrypt in place in 'rr->input' */ 427 rr->data = rr->input; 428 429 enc_err = s->method->ssl3_enc->enc(s, 0); 430 /*- 431 * enc_err is: 432 * 0: (in non-constant time) if the record is publically invalid. 433 * 1: if the padding is valid 434 * -1: if the padding is invalid 435 */ 436 if (enc_err == 0) { 437 al = SSL_AD_DECRYPTION_FAILED; 438 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG); 439 goto f_err; 440 } 441#ifdef TLS_DEBUG 442 printf("dec %d\n", rr->length); 443 { 444 unsigned int z; 445 for (z = 0; z < rr->length; z++) 446 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n'); 447 } 448 printf("\n"); 449#endif 450 451 /* r->length is now the compressed data plus mac */ 452 if ((sess != NULL) && 453 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) { 454 /* s->read_hash != NULL => mac_size != -1 */ 455 unsigned char *mac = NULL; 456 unsigned char mac_tmp[EVP_MAX_MD_SIZE]; 457 mac_size = EVP_MD_CTX_size(s->read_hash); 458 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE); 459 460 /* 461 * kludge: *_cbc_remove_padding passes padding length in rr->type 462 */ 463 orig_len = rr->length + ((unsigned int)rr->type >> 8); 464 465 /* 466 * orig_len is the length of the record before any padding was 467 * removed. This is public information, as is the MAC in use, 468 * therefore we can safely process the record in a different amount 469 * of time if it's too short to possibly contain a MAC. 470 */ 471 if (orig_len < mac_size || 472 /* CBC records must have a padding length byte too. */ 473 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE && 474 orig_len < mac_size + 1)) { 475 al = SSL_AD_DECODE_ERROR; 476 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT); 477 goto f_err; 478 } 479 480 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) { 481 /* 482 * We update the length so that the TLS header bytes can be 483 * constructed correctly but we need to extract the MAC in 484 * constant time from within the record, without leaking the 485 * contents of the padding bytes. 486 */ 487 mac = mac_tmp; 488 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len); 489 rr->length -= mac_size; 490 } else { 491 /* 492 * In this case there's no padding, so |orig_len| equals 493 * |rec->length| and we checked that there's enough bytes for 494 * |mac_size| above. 495 */ 496 rr->length -= mac_size; 497 mac = &rr->data[rr->length]; 498 } 499 500 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ ); 501 if (i < 0 || mac == NULL 502 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) 503 enc_err = -1; 504 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra + mac_size) 505 enc_err = -1; 506 } 507 508 if (enc_err < 0) { 509 /* 510 * A separate 'decryption_failed' alert was introduced with TLS 1.0, 511 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption 512 * failure is directly visible from the ciphertext anyway, we should 513 * not reveal which kind of error occured -- this might become 514 * visible to an attacker (e.g. via a logfile) 515 */ 516 al = SSL_AD_BAD_RECORD_MAC; 517 SSLerr(SSL_F_SSL3_GET_RECORD, 518 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC); 519 goto f_err; 520 } 521 522 /* r->length is now just compressed */ 523 if (s->expand != NULL) { 524 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra) { 525 al = SSL_AD_RECORD_OVERFLOW; 526 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG); 527 goto f_err; 528 } 529 if (!ssl3_do_uncompress(s)) { 530 al = SSL_AD_DECOMPRESSION_FAILURE; 531 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION); 532 goto f_err; 533 } 534 } 535 536 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH + extra) { 537 al = SSL_AD_RECORD_OVERFLOW; 538 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG); 539 goto f_err; 540 } 541 542 rr->off = 0; 543 /*- 544 * So at this point the following is true 545 * ssl->s3->rrec.type is the type of record 546 * ssl->s3->rrec.length == number of bytes in record 547 * ssl->s3->rrec.off == offset to first valid byte 548 * ssl->s3->rrec.data == where to take bytes from, increment 549 * after use :-). 550 */ 551 552 /* we have pulled in a full packet so zero things */ 553 s->packet_length = 0; 554 555 /* just read a 0 length packet */ 556 if (rr->length == 0) { 557 empty_record_count++; 558 if (empty_record_count > MAX_EMPTY_RECORDS) { 559 al = SSL_AD_UNEXPECTED_MESSAGE; 560 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL); 561 goto f_err; 562 } 563 goto again; 564 } 565#if 0 566 fprintf(stderr, "Ultimate Record type=%d, Length=%d\n", rr->type, 567 rr->length); 568#endif 569 570 return (1); 571 572 f_err: 573 ssl3_send_alert(s, SSL3_AL_FATAL, al); 574 err: 575 return (ret); 576} 577 578int ssl3_do_uncompress(SSL *ssl) 579{ 580#ifndef OPENSSL_NO_COMP 581 int i; 582 SSL3_RECORD *rr; 583 584 rr = &(ssl->s3->rrec); 585 i = COMP_expand_block(ssl->expand, rr->comp, 586 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, 587 (int)rr->length); 588 if (i < 0) 589 return (0); 590 else 591 rr->length = i; 592 rr->data = rr->comp; 593#endif 594 return (1); 595} 596 597int ssl3_do_compress(SSL *ssl) 598{ 599#ifndef OPENSSL_NO_COMP 600 int i; 601 SSL3_RECORD *wr; 602 603 wr = &(ssl->s3->wrec); 604 i = COMP_compress_block(ssl->compress, wr->data, 605 SSL3_RT_MAX_COMPRESSED_LENGTH, 606 wr->input, (int)wr->length); 607 if (i < 0) 608 return (0); 609 else 610 wr->length = i; 611 612 wr->input = wr->data; 613#endif 614 return (1); 615} 616 617/* 618 * Call this to write data in records of type 'type' It will return <= 0 if 619 * not all data has been sent or non-blocking IO. 620 */ 621int ssl3_write_bytes(SSL *s, int type, const void *buf_, int len) 622{ 623 const unsigned char *buf = buf_; 624 unsigned int n, nw; 625 int i, tot; 626 627 s->rwstate = SSL_NOTHING; 628 OPENSSL_assert(s->s3->wnum <= INT_MAX); 629 tot = s->s3->wnum; 630 s->s3->wnum = 0; 631 632 if (SSL_in_init(s) && !s->in_handshake) { 633 i = s->handshake_func(s); 634 if (i < 0) 635 return (i); 636 if (i == 0) { 637 SSLerr(SSL_F_SSL3_WRITE_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 638 return -1; 639 } 640 } 641 642 /* 643 * ensure that if we end up with a smaller value of data to write out 644 * than the the original len from a write which didn't complete for 645 * non-blocking I/O and also somehow ended up avoiding the check for 646 * this in ssl3_write_pending/SSL_R_BAD_WRITE_RETRY as it must never be 647 * possible to end up with (len-tot) as a large number that will then 648 * promptly send beyond the end of the users buffer ... so we trap and 649 * report the error in a way the user will notice 650 */ 651 if (len < tot) { 652 SSLerr(SSL_F_SSL3_WRITE_BYTES, SSL_R_BAD_LENGTH); 653 return (-1); 654 } 655 656 n = (len - tot); 657 for (;;) { 658 if (n > s->max_send_fragment) 659 nw = s->max_send_fragment; 660 else 661 nw = n; 662 663 i = do_ssl3_write(s, type, &(buf[tot]), nw, 0); 664 if (i <= 0) { 665 s->s3->wnum = tot; 666 return i; 667 } 668 669 if ((i == (int)n) || 670 (type == SSL3_RT_APPLICATION_DATA && 671 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE))) { 672 /* 673 * next chunk of data should get another prepended empty fragment 674 * in ciphersuites with known-IV weakness: 675 */ 676 s->s3->empty_fragment_done = 0; 677 678 return tot + i; 679 } 680 681 n -= i; 682 tot += i; 683 } 684} 685 686static int do_ssl3_write(SSL *s, int type, const unsigned char *buf, 687 unsigned int len, int create_empty_fragment) 688{ 689 unsigned char *p, *plen; 690 int i, mac_size, clear = 0; 691 int prefix_len = 0; 692 int eivlen; 693 long align = 0; 694 SSL3_RECORD *wr; 695 SSL3_BUFFER *wb = &(s->s3->wbuf); 696 SSL_SESSION *sess; 697 698 /* 699 * first check if there is a SSL3_BUFFER still being written out. This 700 * will happen with non blocking IO 701 */ 702 if (wb->left != 0) 703 return (ssl3_write_pending(s, type, buf, len)); 704 705 /* If we have an alert to send, lets send it */ 706 if (s->s3->alert_dispatch) { 707 i = s->method->ssl_dispatch_alert(s); 708 if (i <= 0) 709 return (i); 710 /* if it went, fall through and send more stuff */ 711 } 712 713 if (wb->buf == NULL) 714 if (!ssl3_setup_write_buffer(s)) 715 return -1; 716 717 if (len == 0 && !create_empty_fragment) 718 return 0; 719 720 wr = &(s->s3->wrec); 721 sess = s->session; 722 723 if ((sess == NULL) || 724 (s->enc_write_ctx == NULL) || 725 (EVP_MD_CTX_md(s->write_hash) == NULL)) { 726#if 1 727 clear = s->enc_write_ctx ? 0 : 1; /* must be AEAD cipher */ 728#else 729 clear = 1; 730#endif 731 mac_size = 0; 732 } else { 733 mac_size = EVP_MD_CTX_size(s->write_hash); 734 if (mac_size < 0) 735 goto err; 736 } 737 738 /* 739 * 'create_empty_fragment' is true only when this function calls itself 740 */ 741 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done) { 742 /* 743 * countermeasure against known-IV weakness in CBC ciphersuites (see 744 * http://www.openssl.org/~bodo/tls-cbc.txt) 745 */ 746 747 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) { 748 /* 749 * recursive function call with 'create_empty_fragment' set; this 750 * prepares and buffers the data for an empty fragment (these 751 * 'prefix_len' bytes are sent out later together with the actual 752 * payload) 753 */ 754 prefix_len = do_ssl3_write(s, type, buf, 0, 1); 755 if (prefix_len <= 0) 756 goto err; 757 758 if (prefix_len > 759 (SSL3_RT_HEADER_LENGTH + SSL3_RT_SEND_MAX_ENCRYPTED_OVERHEAD)) 760 { 761 /* insufficient space */ 762 SSLerr(SSL_F_DO_SSL3_WRITE, ERR_R_INTERNAL_ERROR); 763 goto err; 764 } 765 } 766 767 s->s3->empty_fragment_done = 1; 768 } 769 770 if (create_empty_fragment) { 771#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 772 /* 773 * extra fragment would be couple of cipher blocks, which would be 774 * multiple of SSL3_ALIGN_PAYLOAD, so if we want to align the real 775 * payload, then we can just pretent we simply have two headers. 776 */ 777 align = (long)wb->buf + 2 * SSL3_RT_HEADER_LENGTH; 778 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 779#endif 780 p = wb->buf + align; 781 wb->offset = align; 782 } else if (prefix_len) { 783 p = wb->buf + wb->offset + prefix_len; 784 } else { 785#if defined(SSL3_ALIGN_PAYLOAD) && SSL3_ALIGN_PAYLOAD!=0 786 align = (long)wb->buf + SSL3_RT_HEADER_LENGTH; 787 align = (-align) & (SSL3_ALIGN_PAYLOAD - 1); 788#endif 789 p = wb->buf + align; 790 wb->offset = align; 791 } 792 793 /* write the header */ 794 795 *(p++) = type & 0xff; 796 wr->type = type; 797 798 *(p++) = (s->version >> 8); 799 /* 800 * Some servers hang if iniatial client hello is larger than 256 bytes 801 * and record version number > TLS 1.0 802 */ 803 if (s->state == SSL3_ST_CW_CLNT_HELLO_B 804 && !s->renegotiate && TLS1_get_version(s) > TLS1_VERSION) 805 *(p++) = 0x1; 806 else 807 *(p++) = s->version & 0xff; 808 809 /* field where we are to write out packet length */ 810 plen = p; 811 p += 2; 812 /* Explicit IV length, block ciphers and TLS version 1.1 or later */ 813 if (s->enc_write_ctx && s->version >= TLS1_1_VERSION) { 814 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx); 815 if (mode == EVP_CIPH_CBC_MODE) { 816 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx); 817 if (eivlen <= 1) 818 eivlen = 0; 819 } 820 /* Need explicit part of IV for GCM mode */ 821 else if (mode == EVP_CIPH_GCM_MODE) 822 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN; 823 else 824 eivlen = 0; 825 } else 826 eivlen = 0; 827 828 /* lets setup the record stuff. */ 829 wr->data = p + eivlen; 830 wr->length = (int)len; 831 wr->input = (unsigned char *)buf; 832 833 /* 834 * we now 'read' from wr->input, wr->length bytes into wr->data 835 */ 836 837 /* first we compress */ 838 if (s->compress != NULL) { 839 if (!ssl3_do_compress(s)) { 840 SSLerr(SSL_F_DO_SSL3_WRITE, SSL_R_COMPRESSION_FAILURE); 841 goto err; 842 } 843 } else { 844 memcpy(wr->data, wr->input, wr->length); 845 wr->input = wr->data; 846 } 847 848 /* 849 * we should still have the output to wr->data and the input from 850 * wr->input. Length should be wr->length. wr->data still points in the 851 * wb->buf 852 */ 853 854 if (mac_size != 0) { 855 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0) 856 goto err; 857 wr->length += mac_size; 858 } 859 860 wr->input = p; 861 wr->data = p; 862 863 if (eivlen) { 864 /* 865 * if (RAND_pseudo_bytes(p, eivlen) <= 0) goto err; 866 */ 867 wr->length += eivlen; 868 } 869 870 if (s->method->ssl3_enc->enc(s, 1) < 1) 871 goto err; 872 873 /* record length after mac and block padding */ 874 s2n(wr->length, plen); 875 876 /* 877 * we should now have wr->data pointing to the encrypted data, which is 878 * wr->length long 879 */ 880 wr->type = type; /* not needed but helps for debugging */ 881 wr->length += SSL3_RT_HEADER_LENGTH; 882 883 if (create_empty_fragment) { 884 /* 885 * we are in a recursive call; just return the length, don't write 886 * out anything here 887 */ 888 return wr->length; 889 } 890 891 /* now let's set up wb */ 892 wb->left = prefix_len + wr->length; 893 894 /* 895 * memorize arguments so that ssl3_write_pending can detect bad write 896 * retries later 897 */ 898 s->s3->wpend_tot = len; 899 s->s3->wpend_buf = buf; 900 s->s3->wpend_type = type; 901 s->s3->wpend_ret = len; 902 903 /* we now just need to write the buffer */ 904 return ssl3_write_pending(s, type, buf, len); 905 err: 906 return -1; 907} 908 909/* if s->s3->wbuf.left != 0, we need to call this */ 910int ssl3_write_pending(SSL *s, int type, const unsigned char *buf, 911 unsigned int len) 912{ 913 int i; 914 SSL3_BUFFER *wb = &(s->s3->wbuf); 915 916/* XXXX */ 917 if ((s->s3->wpend_tot > (int)len) 918 || ((s->s3->wpend_buf != buf) && 919 !(s->mode & SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER)) 920 || (s->s3->wpend_type != type)) { 921 SSLerr(SSL_F_SSL3_WRITE_PENDING, SSL_R_BAD_WRITE_RETRY); 922 return (-1); 923 } 924 925 for (;;) { 926 clear_sys_error(); 927 if (s->wbio != NULL) { 928 s->rwstate = SSL_WRITING; 929 i = BIO_write(s->wbio, 930 (char *)&(wb->buf[wb->offset]), 931 (unsigned int)wb->left); 932 } else { 933 SSLerr(SSL_F_SSL3_WRITE_PENDING, SSL_R_BIO_NOT_SET); 934 i = -1; 935 } 936 if (i == wb->left) { 937 wb->left = 0; 938 wb->offset += i; 939 if (s->mode & SSL_MODE_RELEASE_BUFFERS && 940 SSL_version(s) != DTLS1_VERSION 941 && SSL_version(s) != DTLS1_BAD_VER) 942 ssl3_release_write_buffer(s); 943 s->rwstate = SSL_NOTHING; 944 return (s->s3->wpend_ret); 945 } else if (i <= 0) { 946 if (s->version == DTLS1_VERSION || s->version == DTLS1_BAD_VER) { 947 /* 948 * For DTLS, just drop it. That's kind of the whole point in 949 * using a datagram service 950 */ 951 wb->left = 0; 952 } 953 return (i); 954 } 955 wb->offset += i; 956 wb->left -= i; 957 } 958} 959 960/*- 961 * Return up to 'len' payload bytes received in 'type' records. 962 * 'type' is one of the following: 963 * 964 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us) 965 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us) 966 * - 0 (during a shutdown, no data has to be returned) 967 * 968 * If we don't have stored data to work from, read a SSL/TLS record first 969 * (possibly multiple records if we still don't have anything to return). 970 * 971 * This function must handle any surprises the peer may have for us, such as 972 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really 973 * a surprise, but handled as if it were), or renegotiation requests. 974 * Also if record payloads contain fragments too small to process, we store 975 * them until there is enough for the respective protocol (the record protocol 976 * may use arbitrary fragmentation and even interleaving): 977 * Change cipher spec protocol 978 * just 1 byte needed, no need for keeping anything stored 979 * Alert protocol 980 * 2 bytes needed (AlertLevel, AlertDescription) 981 * Handshake protocol 982 * 4 bytes needed (HandshakeType, uint24 length) -- we just have 983 * to detect unexpected Client Hello and Hello Request messages 984 * here, anything else is handled by higher layers 985 * Application data protocol 986 * none of our business 987 */ 988int ssl3_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek) 989{ 990 int al, i, j, ret; 991 unsigned int n; 992 SSL3_RECORD *rr; 993 void (*cb) (const SSL *ssl, int type2, int val) = NULL; 994 995 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */ 996 if (!ssl3_setup_read_buffer(s)) 997 return (-1); 998 999 if ((type && (type != SSL3_RT_APPLICATION_DATA) 1000 && (type != SSL3_RT_HANDSHAKE)) || (peek 1001 && (type != 1002 SSL3_RT_APPLICATION_DATA))) { 1003 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR); 1004 return -1; 1005 } 1006 1007 if ((type == SSL3_RT_HANDSHAKE) && (s->s3->handshake_fragment_len > 0)) 1008 /* (partially) satisfy request from storage */ 1009 { 1010 unsigned char *src = s->s3->handshake_fragment; 1011 unsigned char *dst = buf; 1012 unsigned int k; 1013 1014 /* peek == 0 */ 1015 n = 0; 1016 while ((len > 0) && (s->s3->handshake_fragment_len > 0)) { 1017 *dst++ = *src++; 1018 len--; 1019 s->s3->handshake_fragment_len--; 1020 n++; 1021 } 1022 /* move any remaining fragment bytes: */ 1023 for (k = 0; k < s->s3->handshake_fragment_len; k++) 1024 s->s3->handshake_fragment[k] = *src++; 1025 return n; 1026 } 1027 1028 /* 1029 * Now s->s3->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. 1030 */ 1031 1032 if (!s->in_handshake && SSL_in_init(s)) { 1033 /* type == SSL3_RT_APPLICATION_DATA */ 1034 i = s->handshake_func(s); 1035 if (i < 0) 1036 return (i); 1037 if (i == 0) { 1038 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1039 return (-1); 1040 } 1041 } 1042 start: 1043 s->rwstate = SSL_NOTHING; 1044 1045 /*- 1046 * s->s3->rrec.type - is the type of record 1047 * s->s3->rrec.data, - data 1048 * s->s3->rrec.off, - offset into 'data' for next read 1049 * s->s3->rrec.length, - number of bytes. 1050 */ 1051 rr = &(s->s3->rrec); 1052 1053 /* get new packet if necessary */ 1054 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) { 1055 ret = ssl3_get_record(s); 1056 if (ret <= 0) 1057 return (ret); 1058 } 1059 1060 /* 1061 * Reset the count of consecutive warning alerts if we've got a non-empty 1062 * record that isn't an alert. 1063 */ 1064 if (rr->type != SSL3_RT_ALERT && rr->length != 0) 1065 s->s3->alert_count = 0; 1066 1067 /* we now have a packet which can be read and processed */ 1068 1069 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec, 1070 * reset by ssl3_get_finished */ 1071 && (rr->type != SSL3_RT_HANDSHAKE)) { 1072 al = SSL_AD_UNEXPECTED_MESSAGE; 1073 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_DATA_BETWEEN_CCS_AND_FINISHED); 1074 goto f_err; 1075 } 1076 1077 /* 1078 * If the other end has shut down, throw anything we read away (even in 1079 * 'peek' mode) 1080 */ 1081 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) { 1082 rr->length = 0; 1083 s->rwstate = SSL_NOTHING; 1084 return (0); 1085 } 1086 1087 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or 1088 * SSL3_RT_HANDSHAKE */ 1089 /* 1090 * make sure that we are not getting application data when we are 1091 * doing a handshake for the first time 1092 */ 1093 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) && 1094 (s->enc_read_ctx == NULL)) { 1095 al = SSL_AD_UNEXPECTED_MESSAGE; 1096 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE); 1097 goto f_err; 1098 } 1099 1100 if (len <= 0) 1101 return (len); 1102 1103 if ((unsigned int)len > rr->length) 1104 n = rr->length; 1105 else 1106 n = (unsigned int)len; 1107 1108 memcpy(buf, &(rr->data[rr->off]), n); 1109 if (!peek) { 1110 rr->length -= n; 1111 rr->off += n; 1112 if (rr->length == 0) { 1113 s->rstate = SSL_ST_READ_HEADER; 1114 rr->off = 0; 1115 if (s->mode & SSL_MODE_RELEASE_BUFFERS 1116 && s->s3->rbuf.left == 0) 1117 ssl3_release_read_buffer(s); 1118 } 1119 } 1120 return (n); 1121 } 1122 1123 /* 1124 * If we get here, then type != rr->type; if we have a handshake message, 1125 * then it was unexpected (Hello Request or Client Hello). 1126 */ 1127 1128 /* 1129 * In case of record types for which we have 'fragment' storage, fill 1130 * that so that we can process the data at a fixed place. 1131 */ 1132 { 1133 unsigned int dest_maxlen = 0; 1134 unsigned char *dest = NULL; 1135 unsigned int *dest_len = NULL; 1136 1137 if (rr->type == SSL3_RT_HANDSHAKE) { 1138 dest_maxlen = sizeof s->s3->handshake_fragment; 1139 dest = s->s3->handshake_fragment; 1140 dest_len = &s->s3->handshake_fragment_len; 1141 } else if (rr->type == SSL3_RT_ALERT) { 1142 dest_maxlen = sizeof s->s3->alert_fragment; 1143 dest = s->s3->alert_fragment; 1144 dest_len = &s->s3->alert_fragment_len; 1145 } 1146#ifndef OPENSSL_NO_HEARTBEATS 1147 else if (rr->type == TLS1_RT_HEARTBEAT) { 1148 tls1_process_heartbeat(s); 1149 1150 /* Exit and notify application to read again */ 1151 rr->length = 0; 1152 s->rwstate = SSL_READING; 1153 BIO_clear_retry_flags(SSL_get_rbio(s)); 1154 BIO_set_retry_read(SSL_get_rbio(s)); 1155 return (-1); 1156 } 1157#endif 1158 1159 if (dest_maxlen > 0) { 1160 n = dest_maxlen - *dest_len; /* available space in 'dest' */ 1161 if (rr->length < n) 1162 n = rr->length; /* available bytes */ 1163 1164 /* now move 'n' bytes: */ 1165 while (n-- > 0) { 1166 dest[(*dest_len)++] = rr->data[rr->off++]; 1167 rr->length--; 1168 } 1169 1170 if (*dest_len < dest_maxlen) 1171 goto start; /* fragment was too small */ 1172 } 1173 } 1174 1175 /*- 1176 * s->s3->handshake_fragment_len == 4 iff rr->type == SSL3_RT_HANDSHAKE; 1177 * s->s3->alert_fragment_len == 2 iff rr->type == SSL3_RT_ALERT. 1178 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) 1179 */ 1180 1181 /* If we are a client, check for an incoming 'Hello Request': */ 1182 if ((!s->server) && 1183 (s->s3->handshake_fragment_len >= 4) && 1184 (s->s3->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) && 1185 (s->session != NULL) && (s->session->cipher != NULL)) { 1186 s->s3->handshake_fragment_len = 0; 1187 1188 if ((s->s3->handshake_fragment[1] != 0) || 1189 (s->s3->handshake_fragment[2] != 0) || 1190 (s->s3->handshake_fragment[3] != 0)) { 1191 al = SSL_AD_DECODE_ERROR; 1192 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_BAD_HELLO_REQUEST); 1193 goto f_err; 1194 } 1195 1196 if (s->msg_callback) 1197 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 1198 s->s3->handshake_fragment, 4, s, 1199 s->msg_callback_arg); 1200 1201 if (SSL_is_init_finished(s) && 1202 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) && 1203 !s->s3->renegotiate) { 1204 ssl3_renegotiate(s); 1205 if (ssl3_renegotiate_check(s)) { 1206 i = s->handshake_func(s); 1207 if (i < 0) 1208 return (i); 1209 if (i == 0) { 1210 SSLerr(SSL_F_SSL3_READ_BYTES, 1211 SSL_R_SSL_HANDSHAKE_FAILURE); 1212 return (-1); 1213 } 1214 1215 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1216 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1217 BIO *bio; 1218 /* 1219 * In the case where we try to read application data, 1220 * but we trigger an SSL handshake, we return -1 with 1221 * the retry option set. Otherwise renegotiation may 1222 * cause nasty problems in the blocking world 1223 */ 1224 s->rwstate = SSL_READING; 1225 bio = SSL_get_rbio(s); 1226 BIO_clear_retry_flags(bio); 1227 BIO_set_retry_read(bio); 1228 return (-1); 1229 } 1230 } 1231 } 1232 } 1233 /* 1234 * we either finished a handshake or ignored the request, now try 1235 * again to obtain the (application) data we were asked for 1236 */ 1237 goto start; 1238 } 1239 /* 1240 * If we are a server and get a client hello when renegotiation isn't 1241 * allowed send back a no renegotiation alert and carry on. WARNING: 1242 * experimental code, needs reviewing (steve) 1243 */ 1244 if (s->server && 1245 SSL_is_init_finished(s) && 1246 !s->s3->send_connection_binding && 1247 (s->version > SSL3_VERSION) && 1248 (s->s3->handshake_fragment_len >= 4) && 1249 (s->s3->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO) && 1250 (s->session != NULL) && (s->session->cipher != NULL) && 1251 !(s->ctx->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) { 1252 /* 1253 * s->s3->handshake_fragment_len = 0; 1254 */ 1255 rr->length = 0; 1256 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION); 1257 goto start; 1258 } 1259 if (s->s3->alert_fragment_len >= 2) { 1260 int alert_level = s->s3->alert_fragment[0]; 1261 int alert_descr = s->s3->alert_fragment[1]; 1262 1263 s->s3->alert_fragment_len = 0; 1264 1265 if (s->msg_callback) 1266 s->msg_callback(0, s->version, SSL3_RT_ALERT, 1267 s->s3->alert_fragment, 2, s, s->msg_callback_arg); 1268 1269 if (s->info_callback != NULL) 1270 cb = s->info_callback; 1271 else if (s->ctx->info_callback != NULL) 1272 cb = s->ctx->info_callback; 1273 1274 if (cb != NULL) { 1275 j = (alert_level << 8) | alert_descr; 1276 cb(s, SSL_CB_READ_ALERT, j); 1277 } 1278 1279 if (alert_level == SSL3_AL_WARNING) { 1280 s->s3->warn_alert = alert_descr; 1281 1282 s->s3->alert_count++; 1283 if (s->s3->alert_count == MAX_WARN_ALERT_COUNT) { 1284 al = SSL_AD_UNEXPECTED_MESSAGE; 1285 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS); 1286 goto f_err; 1287 } 1288 1289 if (alert_descr == SSL_AD_CLOSE_NOTIFY) { 1290 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1291 return (0); 1292 } 1293 /* 1294 * This is a warning but we receive it if we requested 1295 * renegotiation and the peer denied it. Terminate with a fatal 1296 * alert because if application tried to renegotiatie it 1297 * presumably had a good reason and expects it to succeed. In 1298 * future we might have a renegotiation where we don't care if 1299 * the peer refused it where we carry on. 1300 */ 1301 else if (alert_descr == SSL_AD_NO_RENEGOTIATION) { 1302 al = SSL_AD_HANDSHAKE_FAILURE; 1303 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_NO_RENEGOTIATION); 1304 goto f_err; 1305 } 1306#ifdef SSL_AD_MISSING_SRP_USERNAME 1307 else if (alert_descr == SSL_AD_MISSING_SRP_USERNAME) 1308 return (0); 1309#endif 1310 } else if (alert_level == SSL3_AL_FATAL) { 1311 char tmp[16]; 1312 1313 s->rwstate = SSL_NOTHING; 1314 s->s3->fatal_alert = alert_descr; 1315 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr); 1316 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr); 1317 ERR_add_error_data(2, "SSL alert number ", tmp); 1318 s->shutdown |= SSL_RECEIVED_SHUTDOWN; 1319 SSL_CTX_remove_session(s->ctx, s->session); 1320 return (0); 1321 } else { 1322 al = SSL_AD_ILLEGAL_PARAMETER; 1323 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE); 1324 goto f_err; 1325 } 1326 1327 goto start; 1328 } 1329 1330 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a 1331 * shutdown */ 1332 s->rwstate = SSL_NOTHING; 1333 rr->length = 0; 1334 return (0); 1335 } 1336 1337 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) { 1338 /* 1339 * 'Change Cipher Spec' is just a single byte, so we know exactly 1340 * what the record payload has to look like 1341 */ 1342 if ((rr->length != 1) || (rr->off != 0) || 1343 (rr->data[0] != SSL3_MT_CCS)) { 1344 al = SSL_AD_ILLEGAL_PARAMETER; 1345 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC); 1346 goto f_err; 1347 } 1348 1349 /* Check we have a cipher to change to */ 1350 if (s->s3->tmp.new_cipher == NULL) { 1351 al = SSL_AD_UNEXPECTED_MESSAGE; 1352 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_CCS_RECEIVED_EARLY); 1353 goto f_err; 1354 } 1355 1356 if (!(s->s3->flags & SSL3_FLAGS_CCS_OK)) { 1357 al = SSL_AD_UNEXPECTED_MESSAGE; 1358 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_CCS_RECEIVED_EARLY); 1359 goto f_err; 1360 } 1361 1362 s->s3->flags &= ~SSL3_FLAGS_CCS_OK; 1363 1364 rr->length = 0; 1365 1366 if (s->msg_callback) 1367 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 1368 rr->data, 1, s, s->msg_callback_arg); 1369 1370 s->s3->change_cipher_spec = 1; 1371 if (!ssl3_do_change_cipher_spec(s)) 1372 goto err; 1373 else 1374 goto start; 1375 } 1376 1377 /* 1378 * Unexpected handshake message (Client Hello, or protocol violation) 1379 */ 1380 if ((s->s3->handshake_fragment_len >= 4) && !s->in_handshake) { 1381 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) && 1382 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) { 1383#if 0 /* worked only because C operator preferences 1384 * are not as expected (and because this is 1385 * not really needed for clients except for 1386 * detecting protocol violations): */ 1387 s->state = SSL_ST_BEFORE | (s->server) 1388 ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1389#else 1390 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT; 1391#endif 1392 s->renegotiate = 1; 1393 s->new_session = 1; 1394 } 1395 i = s->handshake_func(s); 1396 if (i < 0) 1397 return (i); 1398 if (i == 0) { 1399 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE); 1400 return (-1); 1401 } 1402 1403 if (!(s->mode & SSL_MODE_AUTO_RETRY)) { 1404 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */ 1405 BIO *bio; 1406 /* 1407 * In the case where we try to read application data, but we 1408 * trigger an SSL handshake, we return -1 with the retry 1409 * option set. Otherwise renegotiation may cause nasty 1410 * problems in the blocking world 1411 */ 1412 s->rwstate = SSL_READING; 1413 bio = SSL_get_rbio(s); 1414 BIO_clear_retry_flags(bio); 1415 BIO_set_retry_read(bio); 1416 return (-1); 1417 } 1418 } 1419 goto start; 1420 } 1421 1422 switch (rr->type) { 1423 default: 1424#ifndef OPENSSL_NO_TLS 1425 /* 1426 * TLS up to v1.1 just ignores unknown message types: TLS v1.2 give 1427 * an unexpected message alert. 1428 */ 1429 if (s->version >= TLS1_VERSION && s->version <= TLS1_1_VERSION) { 1430 rr->length = 0; 1431 goto start; 1432 } 1433#endif 1434 al = SSL_AD_UNEXPECTED_MESSAGE; 1435 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1436 goto f_err; 1437 case SSL3_RT_CHANGE_CIPHER_SPEC: 1438 case SSL3_RT_ALERT: 1439 case SSL3_RT_HANDSHAKE: 1440 /* 1441 * we already handled all of these, with the possible exception of 1442 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not 1443 * happen when type != rr->type 1444 */ 1445 al = SSL_AD_UNEXPECTED_MESSAGE; 1446 SSLerr(SSL_F_SSL3_READ_BYTES, ERR_R_INTERNAL_ERROR); 1447 goto f_err; 1448 case SSL3_RT_APPLICATION_DATA: 1449 /* 1450 * At this point, we were expecting handshake data, but have 1451 * application data. If the library was running inside ssl3_read() 1452 * (i.e. in_read_app_data is set) and it makes sense to read 1453 * application data at this point (session renegotiation not yet 1454 * started), we will indulge it. 1455 */ 1456 if (s->s3->in_read_app_data && 1457 (s->s3->total_renegotiations != 0) && 1458 (((s->state & SSL_ST_CONNECT) && 1459 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) && 1460 (s->state <= SSL3_ST_CR_SRVR_HELLO_A) 1461 ) || ((s->state & SSL_ST_ACCEPT) && 1462 (s->state <= SSL3_ST_SW_HELLO_REQ_A) && 1463 (s->state >= SSL3_ST_SR_CLNT_HELLO_A) 1464 ) 1465 )) { 1466 s->s3->in_read_app_data = 2; 1467 return (-1); 1468 } else { 1469 al = SSL_AD_UNEXPECTED_MESSAGE; 1470 SSLerr(SSL_F_SSL3_READ_BYTES, SSL_R_UNEXPECTED_RECORD); 1471 goto f_err; 1472 } 1473 } 1474 /* not reached */ 1475 1476 f_err: 1477 ssl3_send_alert(s, SSL3_AL_FATAL, al); 1478 err: 1479 return (-1); 1480} 1481 1482int ssl3_do_change_cipher_spec(SSL *s) 1483{ 1484 int i; 1485 const char *sender; 1486 int slen; 1487 1488 if (s->state & SSL_ST_ACCEPT) 1489 i = SSL3_CHANGE_CIPHER_SERVER_READ; 1490 else 1491 i = SSL3_CHANGE_CIPHER_CLIENT_READ; 1492 1493 if (s->s3->tmp.key_block == NULL) { 1494 if (s->session == NULL || s->session->master_key_length == 0) { 1495 /* might happen if dtls1_read_bytes() calls this */ 1496 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, 1497 SSL_R_CCS_RECEIVED_EARLY); 1498 return (0); 1499 } 1500 1501 s->session->cipher = s->s3->tmp.new_cipher; 1502 if (!s->method->ssl3_enc->setup_key_block(s)) 1503 return (0); 1504 } 1505 1506 if (!s->method->ssl3_enc->change_cipher_state(s, i)) 1507 return (0); 1508 1509 /* 1510 * we have to record the message digest at this point so we can get it 1511 * before we read the finished message 1512 */ 1513 if (s->state & SSL_ST_CONNECT) { 1514 sender = s->method->ssl3_enc->server_finished_label; 1515 slen = s->method->ssl3_enc->server_finished_label_len; 1516 } else { 1517 sender = s->method->ssl3_enc->client_finished_label; 1518 slen = s->method->ssl3_enc->client_finished_label_len; 1519 } 1520 1521 i = s->method->ssl3_enc->final_finish_mac(s, 1522 sender, slen, 1523 s->s3->tmp.peer_finish_md); 1524 if (i == 0) { 1525 SSLerr(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR); 1526 return 0; 1527 } 1528 s->s3->tmp.peer_finish_md_len = i; 1529 1530 return (1); 1531} 1532 1533int ssl3_send_alert(SSL *s, int level, int desc) 1534{ 1535 /* Map tls/ssl alert value to correct one */ 1536 desc = s->method->ssl3_enc->alert_value(desc); 1537 if (s->version == SSL3_VERSION && desc == SSL_AD_PROTOCOL_VERSION) 1538 desc = SSL_AD_HANDSHAKE_FAILURE; /* SSL 3.0 does not have 1539 * protocol_version alerts */ 1540 if (desc < 0) 1541 return -1; 1542 /* If a fatal one, remove from cache */ 1543 if ((level == 2) && (s->session != NULL)) 1544 SSL_CTX_remove_session(s->ctx, s->session); 1545 1546 s->s3->alert_dispatch = 1; 1547 s->s3->send_alert[0] = level; 1548 s->s3->send_alert[1] = desc; 1549 if (s->s3->wbuf.left == 0) /* data still being written out? */ 1550 return s->method->ssl_dispatch_alert(s); 1551 /* 1552 * else data is still being written out, we will get written some time in 1553 * the future 1554 */ 1555 return -1; 1556} 1557 1558int ssl3_dispatch_alert(SSL *s) 1559{ 1560 int i, j; 1561 void (*cb) (const SSL *ssl, int type, int val) = NULL; 1562 1563 s->s3->alert_dispatch = 0; 1564 i = do_ssl3_write(s, SSL3_RT_ALERT, &s->s3->send_alert[0], 2, 0); 1565 if (i <= 0) { 1566 s->s3->alert_dispatch = 1; 1567 } else { 1568 /* 1569 * Alert sent to BIO. If it is important, flush it now. If the 1570 * message does not get sent due to non-blocking IO, we will not 1571 * worry too much. 1572 */ 1573 if (s->s3->send_alert[0] == SSL3_AL_FATAL) 1574 (void)BIO_flush(s->wbio); 1575 1576 if (s->msg_callback) 1577 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 1578 2, s, s->msg_callback_arg); 1579 1580 if (s->info_callback != NULL) 1581 cb = s->info_callback; 1582 else if (s->ctx->info_callback != NULL) 1583 cb = s->ctx->info_callback; 1584 1585 if (cb != NULL) { 1586 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1]; 1587 cb(s, SSL_CB_WRITE_ALERT, j); 1588 } 1589 } 1590 return (i); 1591} 1592