1 /* ssl/record/ssl3_record.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
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.
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).
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.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
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)"
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
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.]
58 /* ====================================================================
59 * Copyright (c) 1998-2015 The OpenSSL Project. All rights reserved.
61 * Redistribution and use in source and binary forms, with or without
62 * modification, are permitted provided that the following conditions
65 * 1. Redistributions of source code must retain the above copyright
66 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
87 * 6. Redistributions of any form whatsoever must retain the following
89 * "This product includes software developed by the OpenSSL Project
90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
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).
112 #include "../ssl_locl.h"
113 #include "../../crypto/constant_time_locl.h"
114 #include <openssl/rand.h>
115 #include "record_locl.h"
117 static const unsigned char ssl3_pad_1[48] = {
118 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
119 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
120 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
121 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
122 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
123 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
126 static const unsigned char ssl3_pad_2[48] = {
127 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
128 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
129 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
130 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
131 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
132 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
135 void SSL3_RECORD_clear(SSL3_RECORD *r)
137 memset(r->seq_num, 0, sizeof(r->seq_num));
140 void SSL3_RECORD_release(SSL3_RECORD *r)
142 OPENSSL_free(r->comp);
146 int SSL3_RECORD_setup(SSL3_RECORD *r)
149 r->comp = (unsigned char *)
150 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
156 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
158 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
162 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
163 * will be processed per call to ssl3_get_record. Without this limit an
164 * attacker could send empty records at a faster rate than we can process and
165 * cause ssl3_get_record to loop forever.
167 #define MAX_EMPTY_RECORDS 32
170 * Call this to get a new input record.
171 * It will return <= 0 if more data is needed, normally due to an error
172 * or non-blocking IO.
173 * When it finishes, one packet has been decoded and can be found in
174 * ssl->s3->rrec.type - is the type of record
175 * ssl->s3->rrec.data, - data
176 * ssl->s3->rrec.length, - number of bytes
178 /* used only by ssl3_read_bytes */
179 int ssl3_get_record(SSL *s)
181 int ssl_major, ssl_minor, al;
182 int enc_err, n, i, ret = -1;
186 unsigned char md[EVP_MAX_MD_SIZE];
190 unsigned empty_record_count = 0;
192 rr = RECORD_LAYER_get_rrec(&s->rlayer);
195 if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
196 extra = SSL3_RT_MAX_EXTRA;
199 if (extra && !s->s3->init_extra) {
201 * An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER set after
202 * ssl3_setup_buffers() was done
204 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
209 /* check if we have the header */
210 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
211 (RECORD_LAYER_get_packet_length(&s->rlayer) < SSL3_RT_HEADER_LENGTH)) {
212 n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
213 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0);
215 return (n); /* error or non-blocking */
216 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
218 p = RECORD_LAYER_get_packet(&s->rlayer);
220 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
221 s->msg_callback_arg);
223 /* Pull apart the header into the SSL3_RECORD */
227 version = (ssl_major << 8) | ssl_minor;
230 /* Lets check version */
231 if (!s->first_packet) {
232 if (version != s->version) {
233 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
234 if ((s->version & 0xFF00) == (version & 0xFF00)
235 && !s->enc_write_ctx && !s->write_hash)
237 * Send back error using their minor version number :-)
239 s->version = (unsigned short)version;
240 al = SSL_AD_PROTOCOL_VERSION;
245 if ((version >> 8) != SSL3_VERSION_MAJOR) {
246 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
251 SSL3_BUFFER_get_len(&s->rlayer.rbuf)
252 - SSL3_RT_HEADER_LENGTH) {
253 al = SSL_AD_RECORD_OVERFLOW;
254 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
258 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
261 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
264 RECORD_LAYER_get_packet_length(&s->rlayer) - SSL3_RT_HEADER_LENGTH) {
265 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
267 n = ssl3_read_n(s, i, i, 1);
269 return (n); /* error or non-blocking io */
271 * now n == rr->length, and s->packet_length == SSL3_RT_HEADER_LENGTH
276 /* set state for later operations */
277 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
280 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
281 * and we have that many bytes in s->packet
283 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
286 * ok, we can now read from 's->packet' data into 'rr' rr->input points
287 * at rr->length bytes, which need to be copied into rr->data by either
288 * the decryption or by the decompression When the data is 'copied' into
289 * the rr->data buffer, rr->input will be pointed at the new buffer
293 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
294 * bytes of encrypted compressed stuff.
297 /* check is not needed I believe */
298 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH + extra) {
299 al = SSL_AD_RECORD_OVERFLOW;
300 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
304 /* decrypt in place in 'rr->input' */
305 rr->data = rr->input;
306 rr->orig_len = rr->length;
308 * If in encrypt-then-mac mode calculate mac from encrypted record. All
309 * the details below are public so no timing details can leak.
311 if (SSL_USE_ETM(s) && s->read_hash) {
313 mac_size = EVP_MD_CTX_size(s->read_hash);
314 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
315 if (rr->length < mac_size) {
316 al = SSL_AD_DECODE_ERROR;
317 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
320 rr->length -= mac_size;
321 mac = rr->data + rr->length;
322 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
323 if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
324 al = SSL_AD_BAD_RECORD_MAC;
325 SSLerr(SSL_F_SSL3_GET_RECORD,
326 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
331 enc_err = s->method->ssl3_enc->enc(s, 0);
334 * 0: (in non-constant time) if the record is publically invalid.
335 * 1: if the padding is valid
336 * -1: if the padding is invalid
339 al = SSL_AD_DECRYPTION_FAILED;
340 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
344 printf("dec %d\n", rr->length);
347 for (z = 0; z < rr->length; z++)
348 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
353 /* r->length is now the compressed data plus mac */
354 if ((sess != NULL) &&
355 (s->enc_read_ctx != NULL) &&
356 (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) {
357 /* s->read_hash != NULL => mac_size != -1 */
358 unsigned char *mac = NULL;
359 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
360 mac_size = EVP_MD_CTX_size(s->read_hash);
361 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
364 * orig_len is the length of the record before any padding was
365 * removed. This is public information, as is the MAC in use,
366 * therefore we can safely process the record in a different amount
367 * of time if it's too short to possibly contain a MAC.
369 if (rr->orig_len < mac_size ||
370 /* CBC records must have a padding length byte too. */
371 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
372 rr->orig_len < mac_size + 1)) {
373 al = SSL_AD_DECODE_ERROR;
374 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
378 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
380 * We update the length so that the TLS header bytes can be
381 * constructed correctly but we need to extract the MAC in
382 * constant time from within the record, without leaking the
383 * contents of the padding bytes.
386 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
387 rr->length -= mac_size;
390 * In this case there's no padding, so |rec->orig_len| equals
391 * |rec->length| and we checked that there's enough bytes for
394 rr->length -= mac_size;
395 mac = &rr->data[rr->length];
398 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
399 if (i < 0 || mac == NULL
400 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
402 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra + mac_size)
408 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
409 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
410 * failure is directly visible from the ciphertext anyway, we should
411 * not reveal which kind of error occurred -- this might become
412 * visible to an attacker (e.g. via a logfile)
414 al = SSL_AD_BAD_RECORD_MAC;
415 SSLerr(SSL_F_SSL3_GET_RECORD,
416 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
420 /* r->length is now just compressed */
421 if (s->expand != NULL) {
422 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra) {
423 al = SSL_AD_RECORD_OVERFLOW;
424 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
427 if (!ssl3_do_uncompress(s)) {
428 al = SSL_AD_DECOMPRESSION_FAILURE;
429 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
434 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH + extra) {
435 al = SSL_AD_RECORD_OVERFLOW;
436 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
442 * So at this point the following is true
443 * ssl->s3->rrec.type is the type of record
444 * ssl->s3->rrec.length == number of bytes in record
445 * ssl->s3->rrec.off == offset to first valid byte
446 * ssl->s3->rrec.data == where to take bytes from, increment
450 /* we have pulled in a full packet so zero things */
451 RECORD_LAYER_reset_packet_length(&s->rlayer);
453 /* just read a 0 length packet */
454 if (rr->length == 0) {
455 empty_record_count++;
456 if (empty_record_count > MAX_EMPTY_RECORDS) {
457 al = SSL_AD_UNEXPECTED_MESSAGE;
458 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
467 ssl3_send_alert(s, SSL3_AL_FATAL, al);
472 int ssl3_do_uncompress(SSL *ssl)
474 #ifndef OPENSSL_NO_COMP
478 rr = RECORD_LAYER_get_rrec(&ssl->rlayer);
479 i = COMP_expand_block(ssl->expand, rr->comp,
480 SSL3_RT_MAX_PLAIN_LENGTH, rr->data,
491 int ssl3_do_compress(SSL *ssl)
493 #ifndef OPENSSL_NO_COMP
497 wr = RECORD_LAYER_get_wrec(&ssl->rlayer);
498 i = COMP_compress_block(ssl->compress, wr->data,
499 SSL3_RT_MAX_COMPRESSED_LENGTH,
500 wr->input, (int)wr->length);
506 wr->input = wr->data;
512 * ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
515 * 0: (in non-constant time) if the record is publically invalid (i.e. too
517 * 1: if the record's padding is valid / the encryption was successful.
518 * -1: if the record's padding is invalid or, if sending, an internal error
521 int ssl3_enc(SSL *s, int send)
526 int bs, i, mac_size = 0;
527 const EVP_CIPHER *enc;
530 ds = s->enc_write_ctx;
531 rec = RECORD_LAYER_get_wrec(&s->rlayer);
532 if (s->enc_write_ctx == NULL)
535 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
537 ds = s->enc_read_ctx;
538 rec = RECORD_LAYER_get_rrec(&s->rlayer);
539 if (s->enc_read_ctx == NULL)
542 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
545 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
546 memmove(rec->data, rec->input, rec->length);
547 rec->input = rec->data;
550 bs = EVP_CIPHER_block_size(ds->cipher);
554 if ((bs != 1) && send) {
555 i = bs - ((int)l % bs);
557 /* we need to add 'i-1' padding bytes */
560 * the last of these zero bytes will be overwritten with the
563 memset(&rec->input[rec->length], 0, i);
565 rec->input[l - 1] = (i - 1);
569 if (l == 0 || l % bs != 0)
571 /* otherwise, rec->length >= bs */
574 if (EVP_Cipher(ds, rec->data, rec->input, l) < 1)
577 if (EVP_MD_CTX_md(s->read_hash) != NULL)
578 mac_size = EVP_MD_CTX_size(s->read_hash);
579 if ((bs != 1) && !send)
580 return ssl3_cbc_remove_padding(s, rec, bs, mac_size);
586 * tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
589 * 0: (in non-constant time) if the record is publically invalid (i.e. too
591 * 1: if the record's padding is valid / the encryption was successful.
592 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
593 * an internal error occurred.
595 int tls1_enc(SSL *s, int send)
600 int bs, i, j, k, pad = 0, ret, mac_size = 0;
601 const EVP_CIPHER *enc;
604 if (EVP_MD_CTX_md(s->write_hash)) {
605 int n = EVP_MD_CTX_size(s->write_hash);
606 OPENSSL_assert(n >= 0);
608 ds = s->enc_write_ctx;
609 rec = RECORD_LAYER_get_wrec(&s->rlayer);
610 if (s->enc_write_ctx == NULL)
614 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
615 /* For TLSv1.1 and later explicit IV */
616 if (SSL_USE_EXPLICIT_IV(s)
617 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
618 ivlen = EVP_CIPHER_iv_length(enc);
622 if (rec->data != rec->input)
624 * we can't write into the input stream: Can this ever
628 "%s:%d: rec->data != rec->input\n",
630 else if (RAND_bytes(rec->input, ivlen) <= 0)
635 if (EVP_MD_CTX_md(s->read_hash)) {
636 int n = EVP_MD_CTX_size(s->read_hash);
637 OPENSSL_assert(n >= 0);
639 ds = s->enc_read_ctx;
640 rec = RECORD_LAYER_get_rrec(&s->rlayer);
641 if (s->enc_read_ctx == NULL)
644 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
647 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
648 memmove(rec->data, rec->input, rec->length);
649 rec->input = rec->data;
653 bs = EVP_CIPHER_block_size(ds->cipher);
655 if (EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
656 unsigned char buf[EVP_AEAD_TLS1_AAD_LEN], *seq;
658 seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer)
659 : RECORD_LAYER_get_read_sequence(&s->rlayer);
661 if (SSL_IS_DTLS(s)) {
662 unsigned char dtlsseq[9], *p = dtlsseq;
664 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
665 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
666 memcpy(p, &seq[2], 6);
667 memcpy(buf, dtlsseq, 8);
670 for (i = 7; i >= 0; i--) { /* increment */
678 buf[9] = (unsigned char)(s->version >> 8);
679 buf[10] = (unsigned char)(s->version);
680 buf[11] = rec->length >> 8;
681 buf[12] = rec->length & 0xff;
682 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
683 EVP_AEAD_TLS1_AAD_LEN, buf);
690 } else if ((bs != 1) && send) {
691 i = bs - ((int)l % bs);
693 /* Add weird padding of upto 256 bytes */
695 /* we need to add 'i' padding bytes of value j */
697 if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) {
698 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
701 for (k = (int)l; k < (int)(l + i); k++)
708 if (l == 0 || l % bs != 0)
712 i = EVP_Cipher(ds, rec->data, rec->input, l);
713 if ((EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_CUSTOM_CIPHER)
716 return -1; /* AEAD can fail to verify MAC */
717 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE && !send) {
718 rec->data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
719 rec->input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
720 rec->length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
724 if (!SSL_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)
725 mac_size = EVP_MD_CTX_size(s->read_hash);
726 if ((bs != 1) && !send)
727 ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
734 int n_ssl3_mac(SSL *ssl, unsigned char *md, int send)
737 unsigned char *mac_sec, *seq;
739 const EVP_MD_CTX *hash;
740 unsigned char *p, rec_char;
746 rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
747 mac_sec = &(ssl->s3->write_mac_secret[0]);
748 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
749 hash = ssl->write_hash;
751 rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
752 mac_sec = &(ssl->s3->read_mac_secret[0]);
753 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
754 hash = ssl->read_hash;
757 t = EVP_MD_CTX_size(hash);
761 npad = (48 / md_size) * md_size;
764 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
765 ssl3_cbc_record_digest_supported(hash)) {
767 * This is a CBC-encrypted record. We must avoid leaking any
768 * timing-side channel information about how many blocks of data we
769 * are hashing because that gives an attacker a timing-oracle.
773 * npad is, at most, 48 bytes and that's with MD5:
774 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
776 * With SHA-1 (the largest hash speced for SSLv3) the hash size
777 * goes up 4, but npad goes down by 8, resulting in a smaller
780 unsigned char header[75];
782 memcpy(header + j, mac_sec, md_size);
784 memcpy(header + j, ssl3_pad_1, npad);
786 memcpy(header + j, seq, 8);
788 header[j++] = rec->type;
789 header[j++] = rec->length >> 8;
790 header[j++] = rec->length & 0xff;
792 /* Final param == is SSLv3 */
793 ssl3_cbc_digest_record(hash,
796 rec->length + md_size, rec->orig_len,
797 mac_sec, md_size, 1);
799 unsigned int md_size_u;
800 /* Chop the digest off the end :-) */
801 EVP_MD_CTX_init(&md_ctx);
803 EVP_MD_CTX_copy_ex(&md_ctx, hash);
804 EVP_DigestUpdate(&md_ctx, mac_sec, md_size);
805 EVP_DigestUpdate(&md_ctx, ssl3_pad_1, npad);
806 EVP_DigestUpdate(&md_ctx, seq, 8);
807 rec_char = rec->type;
808 EVP_DigestUpdate(&md_ctx, &rec_char, 1);
811 EVP_DigestUpdate(&md_ctx, md, 2);
812 EVP_DigestUpdate(&md_ctx, rec->input, rec->length);
813 EVP_DigestFinal_ex(&md_ctx, md, NULL);
815 EVP_MD_CTX_copy_ex(&md_ctx, hash);
816 EVP_DigestUpdate(&md_ctx, mac_sec, md_size);
817 EVP_DigestUpdate(&md_ctx, ssl3_pad_2, npad);
818 EVP_DigestUpdate(&md_ctx, md, md_size);
819 EVP_DigestFinal_ex(&md_ctx, md, &md_size_u);
822 EVP_MD_CTX_cleanup(&md_ctx);
825 ssl3_record_sequence_update(seq);
829 int tls1_mac(SSL *ssl, unsigned char *md, int send)
836 EVP_MD_CTX hmac, *mac_ctx;
837 unsigned char header[13];
838 int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
839 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
843 rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
844 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
845 hash = ssl->write_hash;
847 rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
848 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
849 hash = ssl->read_hash;
852 t = EVP_MD_CTX_size(hash);
853 OPENSSL_assert(t >= 0);
856 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
860 if (!EVP_MD_CTX_copy(&hmac, hash))
865 if (SSL_IS_DTLS(ssl)) {
866 unsigned char dtlsseq[8], *p = dtlsseq;
868 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
869 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
870 memcpy(p, &seq[2], 6);
872 memcpy(header, dtlsseq, 8);
874 memcpy(header, seq, 8);
876 header[8] = rec->type;
877 header[9] = (unsigned char)(ssl->version >> 8);
878 header[10] = (unsigned char)(ssl->version);
879 header[11] = (rec->length) >> 8;
880 header[12] = (rec->length) & 0xff;
882 if (!send && !SSL_USE_ETM(ssl) &&
883 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
884 ssl3_cbc_record_digest_supported(mac_ctx)) {
886 * This is a CBC-encrypted record. We must avoid leaking any
887 * timing-side channel information about how many blocks of data we
888 * are hashing because that gives an attacker a timing-oracle.
890 /* Final param == not SSLv3 */
891 ssl3_cbc_digest_record(mac_ctx,
894 rec->length + md_size, rec->orig_len,
895 ssl->s3->read_mac_secret,
896 ssl->s3->read_mac_secret_size, 0);
898 EVP_DigestSignUpdate(mac_ctx, header, sizeof(header));
899 EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length);
900 t = EVP_DigestSignFinal(mac_ctx, md, &md_size);
901 OPENSSL_assert(t > 0);
902 if (!send && !SSL_USE_ETM(ssl) && FIPS_mode())
903 tls_fips_digest_extra(ssl->enc_read_ctx,
905 rec->length, rec->orig_len);
909 EVP_MD_CTX_cleanup(&hmac);
911 fprintf(stderr, "seq=");
914 for (z = 0; z < 8; z++)
915 fprintf(stderr, "%02X ", seq[z]);
916 fprintf(stderr, "\n");
918 fprintf(stderr, "rec=");
921 for (z = 0; z < rec->length; z++)
922 fprintf(stderr, "%02X ", rec->data[z]);
923 fprintf(stderr, "\n");
927 if (!SSL_IS_DTLS(ssl)) {
928 for (i = 7; i >= 0; i--) {
937 for (z = 0; z < md_size; z++)
938 fprintf(stderr, "%02X ", md[z]);
939 fprintf(stderr, "\n");
946 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
947 * record in |rec| by updating |rec->length| in constant time.
949 * block_size: the block size of the cipher used to encrypt the record.
951 * 0: (in non-constant time) if the record is publicly invalid.
952 * 1: if the padding was valid
955 int ssl3_cbc_remove_padding(const SSL *s,
957 unsigned block_size, unsigned mac_size)
959 unsigned padding_length, good;
960 const unsigned overhead = 1 /* padding length byte */ + mac_size;
963 * These lengths are all public so we can test them in non-constant time.
965 if (overhead > rec->length)
968 padding_length = rec->data[rec->length - 1];
969 good = constant_time_ge(rec->length, padding_length + overhead);
970 /* SSLv3 requires that the padding is minimal. */
971 good &= constant_time_ge(block_size, padding_length + 1);
972 rec->length -= good & (padding_length + 1);
973 return constant_time_select_int(good, 1, -1);
977 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
978 * record in |rec| in constant time and returns 1 if the padding is valid and
979 * -1 otherwise. It also removes any explicit IV from the start of the record
980 * without leaking any timing about whether there was enough space after the
981 * padding was removed.
983 * block_size: the block size of the cipher used to encrypt the record.
985 * 0: (in non-constant time) if the record is publicly invalid.
986 * 1: if the padding was valid
989 int tls1_cbc_remove_padding(const SSL *s,
991 unsigned block_size, unsigned mac_size)
993 unsigned padding_length, good, to_check, i;
994 const unsigned overhead = 1 /* padding length byte */ + mac_size;
995 /* Check if version requires explicit IV */
996 if (SSL_USE_EXPLICIT_IV(s)) {
998 * These lengths are all public so we can test them in non-constant
1001 if (overhead + block_size > rec->length)
1003 /* We can now safely skip explicit IV */
1004 rec->data += block_size;
1005 rec->input += block_size;
1006 rec->length -= block_size;
1007 rec->orig_len -= block_size;
1008 } else if (overhead > rec->length)
1011 padding_length = rec->data[rec->length - 1];
1014 * NB: if compression is in operation the first packet may not be of even
1015 * length so the padding bug check cannot be performed. This bug
1016 * workaround has been around since SSLeay so hopefully it is either
1017 * fixed now or no buggy implementation supports compression [steve]
1019 if ((s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) && !s->expand) {
1020 /* First packet is even in size, so check */
1021 if ((memcmp(RECORD_LAYER_get_read_sequence(&s->rlayer),
1022 "\0\0\0\0\0\0\0\0", 8) == 0) &&
1023 !(padding_length & 1)) {
1024 s->s3->flags |= TLS1_FLAGS_TLS_PADDING_BUG;
1026 if ((s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) && padding_length > 0) {
1031 if (EVP_CIPHER_flags(s->enc_read_ctx->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
1032 /* padding is already verified */
1033 rec->length -= padding_length + 1;
1037 good = constant_time_ge(rec->length, overhead + padding_length);
1039 * The padding consists of a length byte at the end of the record and
1040 * then that many bytes of padding, all with the same value as the length
1041 * byte. Thus, with the length byte included, there are i+1 bytes of
1042 * padding. We can't check just |padding_length+1| bytes because that
1043 * leaks decrypted information. Therefore we always have to check the
1044 * maximum amount of padding possible. (Again, the length of the record
1045 * is public information so we can use it.)
1047 to_check = 255; /* maximum amount of padding. */
1048 if (to_check > rec->length - 1)
1049 to_check = rec->length - 1;
1051 for (i = 0; i < to_check; i++) {
1052 unsigned char mask = constant_time_ge_8(padding_length, i);
1053 unsigned char b = rec->data[rec->length - 1 - i];
1055 * The final |padding_length+1| bytes should all have the value
1056 * |padding_length|. Therefore the XOR should be zero.
1058 good &= ~(mask & (padding_length ^ b));
1062 * If any of the final |padding_length+1| bytes had the wrong value, one
1063 * or more of the lower eight bits of |good| will be cleared.
1065 good = constant_time_eq(0xff, good & 0xff);
1066 rec->length -= good & (padding_length + 1);
1068 return constant_time_select_int(good, 1, -1);
1072 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1073 * constant time (independent of the concrete value of rec->length, which may
1074 * vary within a 256-byte window).
1076 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1080 * rec->orig_len >= md_size
1081 * md_size <= EVP_MAX_MD_SIZE
1083 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1084 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1085 * a single or pair of cache-lines, then the variable memory accesses don't
1086 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1087 * not multi-core and are not considered vulnerable to cache-timing attacks.
1089 #define CBC_MAC_ROTATE_IN_PLACE
1091 void ssl3_cbc_copy_mac(unsigned char *out,
1092 const SSL3_RECORD *rec, unsigned md_size)
1094 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1095 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1096 unsigned char *rotated_mac;
1098 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1102 * mac_end is the index of |rec->data| just after the end of the MAC.
1104 unsigned mac_end = rec->length;
1105 unsigned mac_start = mac_end - md_size;
1107 * scan_start contains the number of bytes that we can ignore because the
1108 * MAC's position can only vary by 255 bytes.
1110 unsigned scan_start = 0;
1112 unsigned div_spoiler;
1113 unsigned rotate_offset;
1115 OPENSSL_assert(rec->orig_len >= md_size);
1116 OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
1118 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1119 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1122 /* This information is public so it's safe to branch based on it. */
1123 if (rec->orig_len > md_size + 255 + 1)
1124 scan_start = rec->orig_len - (md_size + 255 + 1);
1126 * div_spoiler contains a multiple of md_size that is used to cause the
1127 * modulo operation to be constant time. Without this, the time varies
1128 * based on the amount of padding when running on Intel chips at least.
1129 * The aim of right-shifting md_size is so that the compiler doesn't
1130 * figure out that it can remove div_spoiler as that would require it to
1131 * prove that md_size is always even, which I hope is beyond it.
1133 div_spoiler = md_size >> 1;
1134 div_spoiler <<= (sizeof(div_spoiler) - 1) * 8;
1135 rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
1137 memset(rotated_mac, 0, md_size);
1138 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1139 unsigned char mac_started = constant_time_ge_8(i, mac_start);
1140 unsigned char mac_ended = constant_time_ge_8(i, mac_end);
1141 unsigned char b = rec->data[i];
1142 rotated_mac[j++] |= b & mac_started & ~mac_ended;
1143 j &= constant_time_lt(j, md_size);
1146 /* Now rotate the MAC */
1147 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1149 for (i = 0; i < md_size; i++) {
1150 /* in case cache-line is 32 bytes, touch second line */
1151 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1152 out[j++] = rotated_mac[rotate_offset++];
1153 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1156 memset(out, 0, md_size);
1157 rotate_offset = md_size - rotate_offset;
1158 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1159 for (i = 0; i < md_size; i++) {
1160 for (j = 0; j < md_size; j++)
1161 out[j] |= rotated_mac[i] & constant_time_eq_8(j, rotate_offset);
1163 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1168 int dtls1_process_record(SSL *s)
1174 unsigned int mac_size;
1175 unsigned char md[EVP_MAX_MD_SIZE];
1177 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1181 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1182 * and we have that many bytes in s->packet
1184 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1187 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1188 * at rr->length bytes, which need to be copied into rr->data by either
1189 * the decryption or by the decompression When the data is 'copied' into
1190 * the rr->data buffer, rr->input will be pointed at the new buffer
1194 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1195 * bytes of encrypted compressed stuff.
1198 /* check is not needed I believe */
1199 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1200 al = SSL_AD_RECORD_OVERFLOW;
1201 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1205 /* decrypt in place in 'rr->input' */
1206 rr->data = rr->input;
1207 rr->orig_len = rr->length;
1209 enc_err = s->method->ssl3_enc->enc(s, 0);
1212 * 0: (in non-constant time) if the record is publically invalid.
1213 * 1: if the padding is valid
1214 * -1: if the padding is invalid
1217 /* For DTLS we simply ignore bad packets. */
1219 RECORD_LAYER_reset_packet_length(&s->rlayer);
1223 printf("dec %d\n", rr->length);
1226 for (z = 0; z < rr->length; z++)
1227 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1232 /* r->length is now the compressed data plus mac */
1233 if ((sess != NULL) &&
1234 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1235 /* s->read_hash != NULL => mac_size != -1 */
1236 unsigned char *mac = NULL;
1237 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1238 mac_size = EVP_MD_CTX_size(s->read_hash);
1239 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1242 * orig_len is the length of the record before any padding was
1243 * removed. This is public information, as is the MAC in use,
1244 * therefore we can safely process the record in a different amount
1245 * of time if it's too short to possibly contain a MAC.
1247 if (rr->orig_len < mac_size ||
1248 /* CBC records must have a padding length byte too. */
1249 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1250 rr->orig_len < mac_size + 1)) {
1251 al = SSL_AD_DECODE_ERROR;
1252 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1256 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1258 * We update the length so that the TLS header bytes can be
1259 * constructed correctly but we need to extract the MAC in
1260 * constant time from within the record, without leaking the
1261 * contents of the padding bytes.
1264 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
1265 rr->length -= mac_size;
1268 * In this case there's no padding, so |rec->orig_len| equals
1269 * |rec->length| and we checked that there's enough bytes for
1272 rr->length -= mac_size;
1273 mac = &rr->data[rr->length];
1276 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
1277 if (i < 0 || mac == NULL
1278 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
1280 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1285 /* decryption failed, silently discard message */
1287 RECORD_LAYER_reset_packet_length(&s->rlayer);
1291 /* r->length is now just compressed */
1292 if (s->expand != NULL) {
1293 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1294 al = SSL_AD_RECORD_OVERFLOW;
1295 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1296 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1299 if (!ssl3_do_uncompress(s)) {
1300 al = SSL_AD_DECOMPRESSION_FAILURE;
1301 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1306 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1307 al = SSL_AD_RECORD_OVERFLOW;
1308 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1314 * So at this point the following is true
1315 * ssl->s3->rrec.type is the type of record
1316 * ssl->s3->rrec.length == number of bytes in record
1317 * ssl->s3->rrec.off == offset to first valid byte
1318 * ssl->s3->rrec.data == where to take bytes from, increment
1322 /* we have pulled in a full packet so zero things */
1323 RECORD_LAYER_reset_packet_length(&s->rlayer);
1327 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1334 * retrieve a buffered record that belongs to the current epoch, ie,
1337 #define dtls1_get_processed_record(s) \
1338 dtls1_retrieve_buffered_record((s), \
1339 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1342 * Call this to get a new input record.
1343 * It will return <= 0 if more data is needed, normally due to an error
1344 * or non-blocking IO.
1345 * When it finishes, one packet has been decoded and can be found in
1346 * ssl->s3->rrec.type - is the type of record
1347 * ssl->s3->rrec.data, - data
1348 * ssl->s3->rrec.length, - number of bytes
1350 /* used only by dtls1_read_bytes */
1351 int dtls1_get_record(SSL *s)
1353 int ssl_major, ssl_minor;
1356 unsigned char *p = NULL;
1357 unsigned short version;
1358 DTLS1_BITMAP *bitmap;
1359 unsigned int is_next_epoch;
1361 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1364 * The epoch may have changed. If so, process all the pending records.
1365 * This is a non-blocking operation.
1367 if (dtls1_process_buffered_records(s) < 0)
1370 /* if we're renegotiating, then there may be buffered records */
1371 if (dtls1_get_processed_record(s))
1374 /* get something from the wire */
1376 /* check if we have the header */
1377 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1378 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1379 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1380 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0);
1381 /* read timeout is handled by dtls1_read_bytes */
1383 return (n); /* error or non-blocking */
1385 /* this packet contained a partial record, dump it */
1386 if (RECORD_LAYER_get_packet_length(&s->rlayer) != DTLS1_RT_HEADER_LENGTH) {
1387 RECORD_LAYER_reset_packet_length(&s->rlayer);
1391 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1393 p = RECORD_LAYER_get_packet(&s->rlayer);
1395 if (s->msg_callback)
1396 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1397 s, s->msg_callback_arg);
1399 /* Pull apart the header into the DTLS1_RECORD */
1403 version = (ssl_major << 8) | ssl_minor;
1405 /* sequence number is 64 bits, with top 2 bytes = epoch */
1408 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1413 /* Lets check version */
1414 if (!s->first_packet) {
1415 if (version != s->version) {
1416 /* unexpected version, silently discard */
1418 RECORD_LAYER_reset_packet_length(&s->rlayer);
1423 if ((version & 0xff00) != (s->version & 0xff00)) {
1424 /* wrong version, silently discard record */
1426 RECORD_LAYER_reset_packet_length(&s->rlayer);
1430 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1431 /* record too long, silently discard it */
1433 RECORD_LAYER_reset_packet_length(&s->rlayer);
1437 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1440 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1443 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1444 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1446 n = ssl3_read_n(s, i, i, 1);
1447 /* this packet contained a partial record, dump it */
1450 RECORD_LAYER_reset_packet_length(&s->rlayer);
1455 * now n == rr->length, and s->packet_length ==
1456 * DTLS1_RT_HEADER_LENGTH + rr->length
1459 /* set state for later operations */
1460 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1462 /* match epochs. NULL means the packet is dropped on the floor */
1463 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1464 if (bitmap == NULL) {
1466 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1467 goto again; /* get another record */
1469 #ifndef OPENSSL_NO_SCTP
1470 /* Only do replay check if no SCTP bio */
1471 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1474 * Check whether this is a repeat, or aged record. Don't check if
1475 * we're listening and this message is a ClientHello. They can look
1476 * as if they're replayed, since they arrive from different
1477 * connections and would be dropped unnecessarily.
1479 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
1480 RECORD_LAYER_get_packet_length(&s->rlayer)
1481 > DTLS1_RT_HEADER_LENGTH &&
1482 RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]
1483 == SSL3_MT_CLIENT_HELLO) &&
1484 !dtls1_record_replay_check(s, bitmap)) {
1486 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1487 goto again; /* get another record */
1489 #ifndef OPENSSL_NO_SCTP
1493 /* just read a 0 length packet */
1494 if (rr->length == 0)
1498 * If this record is from the next epoch (either HM or ALERT), and a
1499 * handshake is currently in progress, buffer it since it cannot be
1500 * processed at this time. However, do not buffer anything while
1503 if (is_next_epoch) {
1504 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
1505 if (dtls1_buffer_record
1506 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1509 /* Mark receipt of record. */
1510 dtls1_record_bitmap_update(s, bitmap);
1513 RECORD_LAYER_reset_packet_length(&s->rlayer);
1517 if (!dtls1_process_record(s)) {
1519 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1520 goto again; /* get another record */
1522 dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */