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 "internal/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
136 * Clear the contents of an SSL3_RECORD but retain any memory allocated
138 void SSL3_RECORD_clear(SSL3_RECORD *r)
140 unsigned char *comp = r->comp;
142 memset(r, 0, sizeof(*r));
146 void SSL3_RECORD_release(SSL3_RECORD *r)
148 OPENSSL_free(r->comp);
152 int SSL3_RECORD_setup(SSL3_RECORD *r)
155 r->comp = (unsigned char *)
156 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
162 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
164 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
168 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
169 * will be processed per call to ssl3_get_record. Without this limit an
170 * attacker could send empty records at a faster rate than we can process and
171 * cause ssl3_get_record to loop forever.
173 #define MAX_EMPTY_RECORDS 32
175 #define SSL2_RT_HEADER_LENGTH 2
177 * Call this to get a new input record.
178 * It will return <= 0 if more data is needed, normally due to an error
179 * or non-blocking IO.
180 * When it finishes, one packet has been decoded and can be found in
181 * ssl->s3->rrec.type - is the type of record
182 * ssl->s3->rrec.data, - data
183 * ssl->s3->rrec.length, - number of bytes
185 /* used only by ssl3_read_bytes */
186 int ssl3_get_record(SSL *s)
188 int ssl_major, ssl_minor, al;
189 int enc_err, n, i, ret = -1;
193 unsigned char md[EVP_MAX_MD_SIZE];
197 unsigned empty_record_count = 0;
199 rr = RECORD_LAYER_get_rrec(&s->rlayer);
202 if (s->options & SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER)
203 extra = SSL3_RT_MAX_EXTRA;
206 if (extra && !s->s3->init_extra) {
208 * An application error: SLS_OP_MICROSOFT_BIG_SSLV3_BUFFER set after
209 * ssl3_setup_buffers() was done
211 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
216 /* check if we have the header */
217 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
218 (RECORD_LAYER_get_packet_length(&s->rlayer) < SSL3_RT_HEADER_LENGTH)) {
219 n = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
220 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0);
222 return (n); /* error or non-blocking */
223 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
225 p = RECORD_LAYER_get_packet(&s->rlayer);
228 * Check whether this is a regular record or an SSLv2 style record. The
229 * latter is only used in an initial ClientHello for old clients. We
230 * check s->read_hash and s->enc_read_ctx to ensure this does not apply
231 * during renegotiation
233 if (s->first_packet && s->server && !s->read_hash && !s->enc_read_ctx
234 && (p[0] & 0x80) && (p[2] == SSL2_MT_CLIENT_HELLO)) {
235 /* SSLv2 style record */
236 rr->type = SSL3_RT_HANDSHAKE;
237 rr->rec_version = SSL2_VERSION;
239 rr->length = ((p[0] & 0x7f) << 8) | p[1];
241 if (rr->length > SSL3_BUFFER_get_len(&s->rlayer.rbuf)
242 - SSL2_RT_HEADER_LENGTH) {
243 al = SSL_AD_RECORD_OVERFLOW;
244 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
248 if (rr->length < MIN_SSL2_RECORD_LEN) {
249 al = SSL_AD_HANDSHAKE_FAILURE;
250 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
254 /* SSLv3+ style record */
256 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
257 s->msg_callback_arg);
259 /* Pull apart the header into the SSL3_RECORD */
263 version = (ssl_major << 8) | ssl_minor;
264 rr->rec_version = version;
267 /* Lets check version */
268 if (!s->first_packet && version != s->version) {
269 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
270 if ((s->version & 0xFF00) == (version & 0xFF00)
271 && !s->enc_write_ctx && !s->write_hash) {
272 if (rr->type == SSL3_RT_ALERT) {
274 * The record is using an incorrect version number, but
275 * what we've got appears to be an alert. We haven't
276 * read the body yet to check whether its a fatal or
277 * not - but chances are it is. We probably shouldn't
278 * send a fatal alert back. We'll just end.
283 * Send back error using their minor version number :-)
285 s->version = (unsigned short)version;
287 al = SSL_AD_PROTOCOL_VERSION;
291 if ((version >> 8) != SSL3_VERSION_MAJOR) {
292 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
297 SSL3_BUFFER_get_len(&s->rlayer.rbuf)
298 - SSL3_RT_HEADER_LENGTH) {
299 al = SSL_AD_RECORD_OVERFLOW;
300 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
305 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
309 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
310 * Calculate how much more data we need to read for the rest of the record
312 if (rr->rec_version == SSL2_VERSION) {
313 i = rr->length + SSL2_RT_HEADER_LENGTH - SSL3_RT_HEADER_LENGTH;
318 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
320 n = ssl3_read_n(s, i, i, 1);
322 return (n); /* error or non-blocking io */
325 /* set state for later operations */
326 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
329 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length,
330 * or s->packet_length == SSL2_RT_HEADER_LENGTH + rr->length
331 * and we have that many bytes in s->packet
333 if(rr->rec_version == SSL2_VERSION) {
334 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
336 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
340 * ok, we can now read from 's->packet' data into 'rr' rr->input points
341 * at rr->length bytes, which need to be copied into rr->data by either
342 * the decryption or by the decompression When the data is 'copied' into
343 * the rr->data buffer, rr->input will be pointed at the new buffer
347 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
348 * bytes of encrypted compressed stuff.
351 /* check is not needed I believe */
352 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH + extra) {
353 al = SSL_AD_RECORD_OVERFLOW;
354 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
358 /* decrypt in place in 'rr->input' */
359 rr->data = rr->input;
360 rr->orig_len = rr->length;
362 * If in encrypt-then-mac mode calculate mac from encrypted record. All
363 * the details below are public so no timing details can leak.
365 if (SSL_USE_ETM(s) && s->read_hash) {
367 mac_size = EVP_MD_CTX_size(s->read_hash);
368 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
369 if (rr->length < mac_size) {
370 al = SSL_AD_DECODE_ERROR;
371 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
374 rr->length -= mac_size;
375 mac = rr->data + rr->length;
376 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
377 if (i < 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
378 al = SSL_AD_BAD_RECORD_MAC;
379 SSLerr(SSL_F_SSL3_GET_RECORD,
380 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
385 enc_err = s->method->ssl3_enc->enc(s, 0);
388 * 0: (in non-constant time) if the record is publically invalid.
389 * 1: if the padding is valid
390 * -1: if the padding is invalid
393 al = SSL_AD_DECRYPTION_FAILED;
394 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
398 printf("dec %d\n", rr->length);
401 for (z = 0; z < rr->length; z++)
402 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
407 /* r->length is now the compressed data plus mac */
408 if ((sess != NULL) &&
409 (s->enc_read_ctx != NULL) &&
410 (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) {
411 /* s->read_hash != NULL => mac_size != -1 */
412 unsigned char *mac = NULL;
413 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
414 mac_size = EVP_MD_CTX_size(s->read_hash);
415 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
418 * orig_len is the length of the record before any padding was
419 * removed. This is public information, as is the MAC in use,
420 * therefore we can safely process the record in a different amount
421 * of time if it's too short to possibly contain a MAC.
423 if (rr->orig_len < mac_size ||
424 /* CBC records must have a padding length byte too. */
425 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
426 rr->orig_len < mac_size + 1)) {
427 al = SSL_AD_DECODE_ERROR;
428 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
432 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
434 * We update the length so that the TLS header bytes can be
435 * constructed correctly but we need to extract the MAC in
436 * constant time from within the record, without leaking the
437 * contents of the padding bytes.
440 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
441 rr->length -= mac_size;
444 * In this case there's no padding, so |rec->orig_len| equals
445 * |rec->length| and we checked that there's enough bytes for
448 rr->length -= mac_size;
449 mac = &rr->data[rr->length];
452 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
453 if (i < 0 || mac == NULL
454 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
456 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra + mac_size)
462 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
463 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
464 * failure is directly visible from the ciphertext anyway, we should
465 * not reveal which kind of error occurred -- this might become
466 * visible to an attacker (e.g. via a logfile)
468 al = SSL_AD_BAD_RECORD_MAC;
469 SSLerr(SSL_F_SSL3_GET_RECORD,
470 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
474 /* r->length is now just compressed */
475 if (s->expand != NULL) {
476 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + extra) {
477 al = SSL_AD_RECORD_OVERFLOW;
478 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
481 if (!ssl3_do_uncompress(s)) {
482 al = SSL_AD_DECOMPRESSION_FAILURE;
483 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
488 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH + extra) {
489 al = SSL_AD_RECORD_OVERFLOW;
490 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
496 * So at this point the following is true
497 * ssl->s3->rrec.type is the type of record
498 * ssl->s3->rrec.length == number of bytes in record
499 * ssl->s3->rrec.off == offset to first valid byte
500 * ssl->s3->rrec.data == where to take bytes from, increment
504 /* we have pulled in a full packet so zero things */
505 RECORD_LAYER_reset_packet_length(&s->rlayer);
507 /* just read a 0 length packet */
508 if (rr->length == 0) {
509 empty_record_count++;
510 if (empty_record_count > MAX_EMPTY_RECORDS) {
511 al = SSL_AD_UNEXPECTED_MESSAGE;
512 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
521 ssl3_send_alert(s, SSL3_AL_FATAL, al);
526 int ssl3_do_uncompress(SSL *ssl)
528 #ifndef OPENSSL_NO_COMP
532 rr = RECORD_LAYER_get_rrec(&ssl->rlayer);
533 i = COMP_expand_block(ssl->expand, rr->comp,
534 SSL3_RT_MAX_PLAIN_LENGTH, rr->data,
545 int ssl3_do_compress(SSL *ssl)
547 #ifndef OPENSSL_NO_COMP
551 wr = RECORD_LAYER_get_wrec(&ssl->rlayer);
552 i = COMP_compress_block(ssl->compress, wr->data,
553 SSL3_RT_MAX_COMPRESSED_LENGTH,
554 wr->input, (int)wr->length);
560 wr->input = wr->data;
566 * ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
569 * 0: (in non-constant time) if the record is publically invalid (i.e. too
571 * 1: if the record's padding is valid / the encryption was successful.
572 * -1: if the record's padding is invalid or, if sending, an internal error
575 int ssl3_enc(SSL *s, int send)
580 int bs, i, mac_size = 0;
581 const EVP_CIPHER *enc;
584 ds = s->enc_write_ctx;
585 rec = RECORD_LAYER_get_wrec(&s->rlayer);
586 if (s->enc_write_ctx == NULL)
589 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
591 ds = s->enc_read_ctx;
592 rec = RECORD_LAYER_get_rrec(&s->rlayer);
593 if (s->enc_read_ctx == NULL)
596 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
599 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
600 memmove(rec->data, rec->input, rec->length);
601 rec->input = rec->data;
604 bs = EVP_CIPHER_block_size(ds->cipher);
608 if ((bs != 1) && send) {
609 i = bs - ((int)l % bs);
611 /* we need to add 'i-1' padding bytes */
614 * the last of these zero bytes will be overwritten with the
617 memset(&rec->input[rec->length], 0, i);
619 rec->input[l - 1] = (i - 1);
623 if (l == 0 || l % bs != 0)
625 /* otherwise, rec->length >= bs */
628 if (EVP_Cipher(ds, rec->data, rec->input, l) < 1)
631 if (EVP_MD_CTX_md(s->read_hash) != NULL)
632 mac_size = EVP_MD_CTX_size(s->read_hash);
633 if ((bs != 1) && !send)
634 return ssl3_cbc_remove_padding(s, rec, bs, mac_size);
640 * tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
643 * 0: (in non-constant time) if the record is publically invalid (i.e. too
645 * 1: if the record's padding is valid / the encryption was successful.
646 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
647 * an internal error occurred.
649 int tls1_enc(SSL *s, int send)
654 int bs, i, j, k, pad = 0, ret, mac_size = 0;
655 const EVP_CIPHER *enc;
658 if (EVP_MD_CTX_md(s->write_hash)) {
659 int n = EVP_MD_CTX_size(s->write_hash);
660 OPENSSL_assert(n >= 0);
662 ds = s->enc_write_ctx;
663 rec = RECORD_LAYER_get_wrec(&s->rlayer);
664 if (s->enc_write_ctx == NULL)
668 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
669 /* For TLSv1.1 and later explicit IV */
670 if (SSL_USE_EXPLICIT_IV(s)
671 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
672 ivlen = EVP_CIPHER_iv_length(enc);
676 if (rec->data != rec->input)
678 * we can't write into the input stream: Can this ever
682 "%s:%d: rec->data != rec->input\n",
684 else if (RAND_bytes(rec->input, ivlen) <= 0)
689 if (EVP_MD_CTX_md(s->read_hash)) {
690 int n = EVP_MD_CTX_size(s->read_hash);
691 OPENSSL_assert(n >= 0);
693 ds = s->enc_read_ctx;
694 rec = RECORD_LAYER_get_rrec(&s->rlayer);
695 if (s->enc_read_ctx == NULL)
698 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
701 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
702 memmove(rec->data, rec->input, rec->length);
703 rec->input = rec->data;
707 bs = EVP_CIPHER_block_size(ds->cipher);
709 if (EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
710 unsigned char buf[EVP_AEAD_TLS1_AAD_LEN], *seq;
712 seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer)
713 : RECORD_LAYER_get_read_sequence(&s->rlayer);
715 if (SSL_IS_DTLS(s)) {
716 unsigned char dtlsseq[9], *p = dtlsseq;
718 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
719 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
720 memcpy(p, &seq[2], 6);
721 memcpy(buf, dtlsseq, 8);
724 for (i = 7; i >= 0; i--) { /* increment */
732 buf[9] = (unsigned char)(s->version >> 8);
733 buf[10] = (unsigned char)(s->version);
734 buf[11] = rec->length >> 8;
735 buf[12] = rec->length & 0xff;
736 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
737 EVP_AEAD_TLS1_AAD_LEN, buf);
744 } else if ((bs != 1) && send) {
745 i = bs - ((int)l % bs);
747 /* Add weird padding of upto 256 bytes */
749 /* we need to add 'i' padding bytes of value j */
751 for (k = (int)l; k < (int)(l + i); k++)
758 if (l == 0 || l % bs != 0)
762 i = EVP_Cipher(ds, rec->data, rec->input, l);
763 if ((EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_CUSTOM_CIPHER)
766 return -1; /* AEAD can fail to verify MAC */
768 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
769 rec->data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
770 rec->input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
771 rec->length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
772 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
773 rec->data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
774 rec->input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
775 rec->length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
780 if (!SSL_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)
781 mac_size = EVP_MD_CTX_size(s->read_hash);
782 if ((bs != 1) && !send)
783 ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
790 int n_ssl3_mac(SSL *ssl, unsigned char *md, int send)
793 unsigned char *mac_sec, *seq;
794 const EVP_MD_CTX *hash;
795 unsigned char *p, rec_char;
801 rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
802 mac_sec = &(ssl->s3->write_mac_secret[0]);
803 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
804 hash = ssl->write_hash;
806 rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
807 mac_sec = &(ssl->s3->read_mac_secret[0]);
808 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
809 hash = ssl->read_hash;
812 t = EVP_MD_CTX_size(hash);
816 npad = (48 / md_size) * md_size;
819 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
820 ssl3_cbc_record_digest_supported(hash)) {
822 * This is a CBC-encrypted record. We must avoid leaking any
823 * timing-side channel information about how many blocks of data we
824 * are hashing because that gives an attacker a timing-oracle.
828 * npad is, at most, 48 bytes and that's with MD5:
829 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
831 * With SHA-1 (the largest hash speced for SSLv3) the hash size
832 * goes up 4, but npad goes down by 8, resulting in a smaller
835 unsigned char header[75];
837 memcpy(header + j, mac_sec, md_size);
839 memcpy(header + j, ssl3_pad_1, npad);
841 memcpy(header + j, seq, 8);
843 header[j++] = rec->type;
844 header[j++] = rec->length >> 8;
845 header[j++] = rec->length & 0xff;
847 /* Final param == is SSLv3 */
848 if (ssl3_cbc_digest_record(hash,
851 rec->length + md_size, rec->orig_len,
852 mac_sec, md_size, 1) <= 0)
855 unsigned int md_size_u;
856 /* Chop the digest off the end :-) */
857 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
862 rec_char = rec->type;
865 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
866 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
867 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
868 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
869 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
870 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
871 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
872 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
873 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
874 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
875 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
876 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
877 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
878 EVP_MD_CTX_reset(md_ctx);
883 EVP_MD_CTX_free(md_ctx);
886 ssl3_record_sequence_update(seq);
890 int tls1_mac(SSL *ssl, unsigned char *md, int send)
897 EVP_MD_CTX *hmac = NULL, *mac_ctx;
898 unsigned char header[13];
899 int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
900 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
904 rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
905 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
906 hash = ssl->write_hash;
908 rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
909 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
910 hash = ssl->read_hash;
913 t = EVP_MD_CTX_size(hash);
914 OPENSSL_assert(t >= 0);
917 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
921 hmac = EVP_MD_CTX_new();
923 || !EVP_MD_CTX_copy(hmac, hash))
928 if (SSL_IS_DTLS(ssl)) {
929 unsigned char dtlsseq[8], *p = dtlsseq;
931 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
932 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
933 memcpy(p, &seq[2], 6);
935 memcpy(header, dtlsseq, 8);
937 memcpy(header, seq, 8);
939 header[8] = rec->type;
940 header[9] = (unsigned char)(ssl->version >> 8);
941 header[10] = (unsigned char)(ssl->version);
942 header[11] = (rec->length) >> 8;
943 header[12] = (rec->length) & 0xff;
945 if (!send && !SSL_USE_ETM(ssl) &&
946 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
947 ssl3_cbc_record_digest_supported(mac_ctx)) {
949 * This is a CBC-encrypted record. We must avoid leaking any
950 * timing-side channel information about how many blocks of data we
951 * are hashing because that gives an attacker a timing-oracle.
953 /* Final param == not SSLv3 */
954 if (ssl3_cbc_digest_record(mac_ctx,
957 rec->length + md_size, rec->orig_len,
958 ssl->s3->read_mac_secret,
959 ssl->s3->read_mac_secret_size, 0) <= 0) {
960 EVP_MD_CTX_free(hmac);
964 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
965 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
966 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
967 EVP_MD_CTX_free(hmac);
970 if (!send && !SSL_USE_ETM(ssl) && FIPS_mode())
971 tls_fips_digest_extra(ssl->enc_read_ctx,
973 rec->length, rec->orig_len);
976 EVP_MD_CTX_free(hmac);
979 fprintf(stderr, "seq=");
982 for (z = 0; z < 8; z++)
983 fprintf(stderr, "%02X ", seq[z]);
984 fprintf(stderr, "\n");
986 fprintf(stderr, "rec=");
989 for (z = 0; z < rec->length; z++)
990 fprintf(stderr, "%02X ", rec->data[z]);
991 fprintf(stderr, "\n");
995 if (!SSL_IS_DTLS(ssl)) {
996 for (i = 7; i >= 0; i--) {
1005 for (z = 0; z < md_size; z++)
1006 fprintf(stderr, "%02X ", md[z]);
1007 fprintf(stderr, "\n");
1014 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1015 * record in |rec| by updating |rec->length| in constant time.
1017 * block_size: the block size of the cipher used to encrypt the record.
1019 * 0: (in non-constant time) if the record is publicly invalid.
1020 * 1: if the padding was valid
1023 int ssl3_cbc_remove_padding(const SSL *s,
1025 unsigned block_size, unsigned mac_size)
1027 unsigned padding_length, good;
1028 const unsigned overhead = 1 /* padding length byte */ + mac_size;
1031 * These lengths are all public so we can test them in non-constant time.
1033 if (overhead > rec->length)
1036 padding_length = rec->data[rec->length - 1];
1037 good = constant_time_ge(rec->length, padding_length + overhead);
1038 /* SSLv3 requires that the padding is minimal. */
1039 good &= constant_time_ge(block_size, padding_length + 1);
1040 rec->length -= good & (padding_length + 1);
1041 return constant_time_select_int(good, 1, -1);
1045 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1046 * record in |rec| in constant time and returns 1 if the padding is valid and
1047 * -1 otherwise. It also removes any explicit IV from the start of the record
1048 * without leaking any timing about whether there was enough space after the
1049 * padding was removed.
1051 * block_size: the block size of the cipher used to encrypt the record.
1053 * 0: (in non-constant time) if the record is publicly invalid.
1054 * 1: if the padding was valid
1057 int tls1_cbc_remove_padding(const SSL *s,
1059 unsigned block_size, unsigned mac_size)
1061 unsigned padding_length, good, to_check, i;
1062 const unsigned overhead = 1 /* padding length byte */ + mac_size;
1063 /* Check if version requires explicit IV */
1064 if (SSL_USE_EXPLICIT_IV(s)) {
1066 * These lengths are all public so we can test them in non-constant
1069 if (overhead + block_size > rec->length)
1071 /* We can now safely skip explicit IV */
1072 rec->data += block_size;
1073 rec->input += block_size;
1074 rec->length -= block_size;
1075 rec->orig_len -= block_size;
1076 } else if (overhead > rec->length)
1079 padding_length = rec->data[rec->length - 1];
1081 if (EVP_CIPHER_flags(s->enc_read_ctx->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
1082 /* padding is already verified */
1083 rec->length -= padding_length + 1;
1087 good = constant_time_ge(rec->length, overhead + padding_length);
1089 * The padding consists of a length byte at the end of the record and
1090 * then that many bytes of padding, all with the same value as the length
1091 * byte. Thus, with the length byte included, there are i+1 bytes of
1092 * padding. We can't check just |padding_length+1| bytes because that
1093 * leaks decrypted information. Therefore we always have to check the
1094 * maximum amount of padding possible. (Again, the length of the record
1095 * is public information so we can use it.)
1097 to_check = 255; /* maximum amount of padding. */
1098 if (to_check > rec->length - 1)
1099 to_check = rec->length - 1;
1101 for (i = 0; i < to_check; i++) {
1102 unsigned char mask = constant_time_ge_8(padding_length, i);
1103 unsigned char b = rec->data[rec->length - 1 - i];
1105 * The final |padding_length+1| bytes should all have the value
1106 * |padding_length|. Therefore the XOR should be zero.
1108 good &= ~(mask & (padding_length ^ b));
1112 * If any of the final |padding_length+1| bytes had the wrong value, one
1113 * or more of the lower eight bits of |good| will be cleared.
1115 good = constant_time_eq(0xff, good & 0xff);
1116 rec->length -= good & (padding_length + 1);
1118 return constant_time_select_int(good, 1, -1);
1122 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1123 * constant time (independent of the concrete value of rec->length, which may
1124 * vary within a 256-byte window).
1126 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1130 * rec->orig_len >= md_size
1131 * md_size <= EVP_MAX_MD_SIZE
1133 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1134 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1135 * a single or pair of cache-lines, then the variable memory accesses don't
1136 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1137 * not multi-core and are not considered vulnerable to cache-timing attacks.
1139 #define CBC_MAC_ROTATE_IN_PLACE
1141 void ssl3_cbc_copy_mac(unsigned char *out,
1142 const SSL3_RECORD *rec, unsigned md_size)
1144 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1145 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1146 unsigned char *rotated_mac;
1148 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1152 * mac_end is the index of |rec->data| just after the end of the MAC.
1154 unsigned mac_end = rec->length;
1155 unsigned mac_start = mac_end - md_size;
1157 * scan_start contains the number of bytes that we can ignore because the
1158 * MAC's position can only vary by 255 bytes.
1160 unsigned scan_start = 0;
1162 unsigned div_spoiler;
1163 unsigned rotate_offset;
1165 OPENSSL_assert(rec->orig_len >= md_size);
1166 OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
1168 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1169 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1172 /* This information is public so it's safe to branch based on it. */
1173 if (rec->orig_len > md_size + 255 + 1)
1174 scan_start = rec->orig_len - (md_size + 255 + 1);
1176 * div_spoiler contains a multiple of md_size that is used to cause the
1177 * modulo operation to be constant time. Without this, the time varies
1178 * based on the amount of padding when running on Intel chips at least.
1179 * The aim of right-shifting md_size is so that the compiler doesn't
1180 * figure out that it can remove div_spoiler as that would require it to
1181 * prove that md_size is always even, which I hope is beyond it.
1183 div_spoiler = md_size >> 1;
1184 div_spoiler <<= (sizeof(div_spoiler) - 1) * 8;
1185 rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
1187 memset(rotated_mac, 0, md_size);
1188 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1189 unsigned char mac_started = constant_time_ge_8(i, mac_start);
1190 unsigned char mac_ended = constant_time_ge_8(i, mac_end);
1191 unsigned char b = rec->data[i];
1192 rotated_mac[j++] |= b & mac_started & ~mac_ended;
1193 j &= constant_time_lt(j, md_size);
1196 /* Now rotate the MAC */
1197 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1199 for (i = 0; i < md_size; i++) {
1200 /* in case cache-line is 32 bytes, touch second line */
1201 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1202 out[j++] = rotated_mac[rotate_offset++];
1203 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1206 memset(out, 0, md_size);
1207 rotate_offset = md_size - rotate_offset;
1208 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1209 for (i = 0; i < md_size; i++) {
1210 for (j = 0; j < md_size; j++)
1211 out[j] |= rotated_mac[i] & constant_time_eq_8(j, rotate_offset);
1213 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1218 int dtls1_process_record(SSL *s)
1224 unsigned int mac_size;
1225 unsigned char md[EVP_MAX_MD_SIZE];
1227 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1231 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1232 * and we have that many bytes in s->packet
1234 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1237 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1238 * at rr->length bytes, which need to be copied into rr->data by either
1239 * the decryption or by the decompression When the data is 'copied' into
1240 * the rr->data buffer, rr->input will be pointed at the new buffer
1244 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1245 * bytes of encrypted compressed stuff.
1248 /* check is not needed I believe */
1249 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1250 al = SSL_AD_RECORD_OVERFLOW;
1251 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1255 /* decrypt in place in 'rr->input' */
1256 rr->data = rr->input;
1257 rr->orig_len = rr->length;
1259 enc_err = s->method->ssl3_enc->enc(s, 0);
1262 * 0: (in non-constant time) if the record is publically invalid.
1263 * 1: if the padding is valid
1264 * -1: if the padding is invalid
1267 /* For DTLS we simply ignore bad packets. */
1269 RECORD_LAYER_reset_packet_length(&s->rlayer);
1273 printf("dec %d\n", rr->length);
1276 for (z = 0; z < rr->length; z++)
1277 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1282 /* r->length is now the compressed data plus mac */
1283 if ((sess != NULL) &&
1284 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1285 /* s->read_hash != NULL => mac_size != -1 */
1286 unsigned char *mac = NULL;
1287 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1288 mac_size = EVP_MD_CTX_size(s->read_hash);
1289 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1292 * orig_len is the length of the record before any padding was
1293 * removed. This is public information, as is the MAC in use,
1294 * therefore we can safely process the record in a different amount
1295 * of time if it's too short to possibly contain a MAC.
1297 if (rr->orig_len < mac_size ||
1298 /* CBC records must have a padding length byte too. */
1299 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1300 rr->orig_len < mac_size + 1)) {
1301 al = SSL_AD_DECODE_ERROR;
1302 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1306 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1308 * We update the length so that the TLS header bytes can be
1309 * constructed correctly but we need to extract the MAC in
1310 * constant time from within the record, without leaking the
1311 * contents of the padding bytes.
1314 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
1315 rr->length -= mac_size;
1318 * In this case there's no padding, so |rec->orig_len| equals
1319 * |rec->length| and we checked that there's enough bytes for
1322 rr->length -= mac_size;
1323 mac = &rr->data[rr->length];
1326 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
1327 if (i < 0 || mac == NULL
1328 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
1330 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1335 /* decryption failed, silently discard message */
1337 RECORD_LAYER_reset_packet_length(&s->rlayer);
1341 /* r->length is now just compressed */
1342 if (s->expand != NULL) {
1343 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1344 al = SSL_AD_RECORD_OVERFLOW;
1345 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1346 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1349 if (!ssl3_do_uncompress(s)) {
1350 al = SSL_AD_DECOMPRESSION_FAILURE;
1351 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1356 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1357 al = SSL_AD_RECORD_OVERFLOW;
1358 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1364 * So at this point the following is true
1365 * ssl->s3->rrec.type is the type of record
1366 * ssl->s3->rrec.length == number of bytes in record
1367 * ssl->s3->rrec.off == offset to first valid byte
1368 * ssl->s3->rrec.data == where to take bytes from, increment
1372 /* we have pulled in a full packet so zero things */
1373 RECORD_LAYER_reset_packet_length(&s->rlayer);
1377 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1384 * retrieve a buffered record that belongs to the current epoch, ie,
1387 #define dtls1_get_processed_record(s) \
1388 dtls1_retrieve_buffered_record((s), \
1389 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1392 * Call this to get a new input record.
1393 * It will return <= 0 if more data is needed, normally due to an error
1394 * or non-blocking IO.
1395 * When it finishes, one packet has been decoded and can be found in
1396 * ssl->s3->rrec.type - is the type of record
1397 * ssl->s3->rrec.data, - data
1398 * ssl->s3->rrec.length, - number of bytes
1400 /* used only by dtls1_read_bytes */
1401 int dtls1_get_record(SSL *s)
1403 int ssl_major, ssl_minor;
1406 unsigned char *p = NULL;
1407 unsigned short version;
1408 DTLS1_BITMAP *bitmap;
1409 unsigned int is_next_epoch;
1411 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1414 * The epoch may have changed. If so, process all the pending records.
1415 * This is a non-blocking operation.
1417 if (dtls1_process_buffered_records(s) < 0)
1420 /* if we're renegotiating, then there may be buffered records */
1421 if (dtls1_get_processed_record(s))
1424 /* get something from the wire */
1426 /* check if we have the header */
1427 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1428 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1429 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1430 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0);
1431 /* read timeout is handled by dtls1_read_bytes */
1433 return (n); /* error or non-blocking */
1435 /* this packet contained a partial record, dump it */
1436 if (RECORD_LAYER_get_packet_length(&s->rlayer) != DTLS1_RT_HEADER_LENGTH) {
1437 RECORD_LAYER_reset_packet_length(&s->rlayer);
1441 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1443 p = RECORD_LAYER_get_packet(&s->rlayer);
1445 if (s->msg_callback)
1446 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1447 s, s->msg_callback_arg);
1449 /* Pull apart the header into the DTLS1_RECORD */
1453 version = (ssl_major << 8) | ssl_minor;
1455 /* sequence number is 64 bits, with top 2 bytes = epoch */
1458 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1463 /* Lets check version */
1464 if (!s->first_packet) {
1465 if (version != s->version) {
1466 /* unexpected version, silently discard */
1468 RECORD_LAYER_reset_packet_length(&s->rlayer);
1473 if ((version & 0xff00) != (s->version & 0xff00)) {
1474 /* wrong version, silently discard record */
1476 RECORD_LAYER_reset_packet_length(&s->rlayer);
1480 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1481 /* record too long, silently discard it */
1483 RECORD_LAYER_reset_packet_length(&s->rlayer);
1487 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1490 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1493 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1494 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1496 n = ssl3_read_n(s, i, i, 1);
1497 /* this packet contained a partial record, dump it */
1500 RECORD_LAYER_reset_packet_length(&s->rlayer);
1505 * now n == rr->length, and s->packet_length ==
1506 * DTLS1_RT_HEADER_LENGTH + rr->length
1509 /* set state for later operations */
1510 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1512 /* match epochs. NULL means the packet is dropped on the floor */
1513 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1514 if (bitmap == NULL) {
1516 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1517 goto again; /* get another record */
1519 #ifndef OPENSSL_NO_SCTP
1520 /* Only do replay check if no SCTP bio */
1521 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1523 /* Check whether this is a repeat, or aged record. */
1524 if (!dtls1_record_replay_check(s, bitmap)) {
1526 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1527 goto again; /* get another record */
1529 #ifndef OPENSSL_NO_SCTP
1533 /* just read a 0 length packet */
1534 if (rr->length == 0)
1538 * If this record is from the next epoch (either HM or ALERT), and a
1539 * handshake is currently in progress, buffer it since it cannot be
1540 * processed at this time.
1542 if (is_next_epoch) {
1543 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1544 if (dtls1_buffer_record
1545 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1548 /* Mark receipt of record. */
1549 dtls1_record_bitmap_update(s, bitmap);
1552 RECORD_LAYER_reset_packet_length(&s->rlayer);
1556 if (!dtls1_process_record(s)) {
1558 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1559 goto again; /* get another record */
1561 dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */