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>
116 static const unsigned char ssl3_pad_1[48] = {
117 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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
125 static const unsigned char ssl3_pad_2[48] = {
126 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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
134 void SSL3_RECORD_clear(SSL3_RECORD *r)
136 memset(r->seq_num, 0, sizeof(r->seq_num));
139 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, 8);
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);
648 fprintf(stderr, "tls1_enc(%d)\n", send);
649 #endif /* KSSL_DEBUG */
651 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
652 memmove(rec->data, rec->input, rec->length);
653 rec->input = rec->data;
657 bs = EVP_CIPHER_block_size(ds->cipher);
659 if (EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
660 unsigned char buf[13], *seq;
662 seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer)
663 : RECORD_LAYER_get_read_sequence(&s->rlayer);
665 if (SSL_IS_DTLS(s)) {
666 unsigned char dtlsseq[9], *p = dtlsseq;
668 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
669 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
670 memcpy(p, &seq[2], 6);
671 memcpy(buf, dtlsseq, 8);
674 for (i = 7; i >= 0; i--) { /* increment */
682 buf[9] = (unsigned char)(s->version >> 8);
683 buf[10] = (unsigned char)(s->version);
684 buf[11] = rec->length >> 8;
685 buf[12] = rec->length & 0xff;
686 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD, 13, buf);
691 } else if ((bs != 1) && send) {
692 i = bs - ((int)l % bs);
694 /* Add weird padding of upto 256 bytes */
696 /* we need to add 'i' padding bytes of value j */
698 if (s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) {
699 if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
702 for (k = (int)l; k < (int)(l + i); k++)
711 "EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
712 ds, rec->data, rec->input, l);
714 "\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%lu %lu], %d iv_len\n",
715 ds->buf_len, ds->cipher->key_len, DES_KEY_SZ,
716 DES_SCHEDULE_SZ, ds->cipher->iv_len);
717 fprintf(stderr, "\t\tIV: ");
718 for (i = 0; i < ds->cipher->iv_len; i++)
719 fprintf(stderr, "%02X", ds->iv[i]);
720 fprintf(stderr, "\n");
721 fprintf(stderr, "\trec->input=");
722 for (ui = 0; ui < l; ui++)
723 fprintf(stderr, " %02x", rec->input[ui]);
724 fprintf(stderr, "\n");
726 #endif /* KSSL_DEBUG */
729 if (l == 0 || l % bs != 0)
733 i = EVP_Cipher(ds, rec->data, rec->input, l);
734 if ((EVP_CIPHER_flags(ds->cipher) & EVP_CIPH_FLAG_CUSTOM_CIPHER)
737 return -1; /* AEAD can fail to verify MAC */
738 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE && !send) {
739 rec->data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
740 rec->input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
741 rec->length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
746 fprintf(stderr, "\trec->data=");
747 for (i = 0; i < l; i++)
748 fprintf(stderr, " %02x", rec->data[i]);
749 fprintf(stderr, "\n");
751 #endif /* KSSL_DEBUG */
754 if (!SSL_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)
755 mac_size = EVP_MD_CTX_size(s->read_hash);
756 if ((bs != 1) && !send)
757 ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
764 int n_ssl3_mac(SSL *ssl, unsigned char *md, int send)
767 unsigned char *mac_sec, *seq;
769 const EVP_MD_CTX *hash;
770 unsigned char *p, rec_char;
776 rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
777 mac_sec = &(ssl->s3->write_mac_secret[0]);
778 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
779 hash = ssl->write_hash;
781 rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
782 mac_sec = &(ssl->s3->read_mac_secret[0]);
783 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
784 hash = ssl->read_hash;
787 t = EVP_MD_CTX_size(hash);
791 npad = (48 / md_size) * md_size;
794 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
795 ssl3_cbc_record_digest_supported(hash)) {
797 * This is a CBC-encrypted record. We must avoid leaking any
798 * timing-side channel information about how many blocks of data we
799 * are hashing because that gives an attacker a timing-oracle.
803 * npad is, at most, 48 bytes and that's with MD5:
804 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
806 * With SHA-1 (the largest hash speced for SSLv3) the hash size
807 * goes up 4, but npad goes down by 8, resulting in a smaller
810 unsigned char header[75];
812 memcpy(header + j, mac_sec, md_size);
814 memcpy(header + j, ssl3_pad_1, npad);
816 memcpy(header + j, seq, 8);
818 header[j++] = rec->type;
819 header[j++] = rec->length >> 8;
820 header[j++] = rec->length & 0xff;
822 /* Final param == is SSLv3 */
823 ssl3_cbc_digest_record(hash,
826 rec->length + md_size, rec->orig_len,
827 mac_sec, md_size, 1);
829 unsigned int md_size_u;
830 /* Chop the digest off the end :-) */
831 EVP_MD_CTX_init(&md_ctx);
833 EVP_MD_CTX_copy_ex(&md_ctx, hash);
834 EVP_DigestUpdate(&md_ctx, mac_sec, md_size);
835 EVP_DigestUpdate(&md_ctx, ssl3_pad_1, npad);
836 EVP_DigestUpdate(&md_ctx, seq, 8);
837 rec_char = rec->type;
838 EVP_DigestUpdate(&md_ctx, &rec_char, 1);
841 EVP_DigestUpdate(&md_ctx, md, 2);
842 EVP_DigestUpdate(&md_ctx, rec->input, rec->length);
843 EVP_DigestFinal_ex(&md_ctx, md, NULL);
845 EVP_MD_CTX_copy_ex(&md_ctx, hash);
846 EVP_DigestUpdate(&md_ctx, mac_sec, md_size);
847 EVP_DigestUpdate(&md_ctx, ssl3_pad_2, npad);
848 EVP_DigestUpdate(&md_ctx, md, md_size);
849 EVP_DigestFinal_ex(&md_ctx, md, &md_size_u);
852 EVP_MD_CTX_cleanup(&md_ctx);
855 ssl3_record_sequence_update(seq);
859 int tls1_mac(SSL *ssl, unsigned char *md, int send)
866 EVP_MD_CTX hmac, *mac_ctx;
867 unsigned char header[13];
868 int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
869 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
873 rec = RECORD_LAYER_get_wrec(&ssl->rlayer);
874 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
875 hash = ssl->write_hash;
877 rec = RECORD_LAYER_get_rrec(&ssl->rlayer);
878 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
879 hash = ssl->read_hash;
882 t = EVP_MD_CTX_size(hash);
883 OPENSSL_assert(t >= 0);
886 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
890 if (!EVP_MD_CTX_copy(&hmac, hash))
895 if (SSL_IS_DTLS(ssl)) {
896 unsigned char dtlsseq[8], *p = dtlsseq;
898 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
899 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
900 memcpy(p, &seq[2], 6);
902 memcpy(header, dtlsseq, 8);
904 memcpy(header, seq, 8);
906 header[8] = rec->type;
907 header[9] = (unsigned char)(ssl->version >> 8);
908 header[10] = (unsigned char)(ssl->version);
909 header[11] = (rec->length) >> 8;
910 header[12] = (rec->length) & 0xff;
912 if (!send && !SSL_USE_ETM(ssl) &&
913 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
914 ssl3_cbc_record_digest_supported(mac_ctx)) {
916 * This is a CBC-encrypted record. We must avoid leaking any
917 * timing-side channel information about how many blocks of data we
918 * are hashing because that gives an attacker a timing-oracle.
920 /* Final param == not SSLv3 */
921 ssl3_cbc_digest_record(mac_ctx,
924 rec->length + md_size, rec->orig_len,
925 ssl->s3->read_mac_secret,
926 ssl->s3->read_mac_secret_size, 0);
928 EVP_DigestSignUpdate(mac_ctx, header, sizeof(header));
929 EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length);
930 t = EVP_DigestSignFinal(mac_ctx, md, &md_size);
931 OPENSSL_assert(t > 0);
932 if (!send && !SSL_USE_ETM(ssl) && FIPS_mode())
933 tls_fips_digest_extra(ssl->enc_read_ctx,
935 rec->length, rec->orig_len);
939 EVP_MD_CTX_cleanup(&hmac);
941 fprintf(stderr, "seq=");
944 for (z = 0; z < 8; z++)
945 fprintf(stderr, "%02X ", seq[z]);
946 fprintf(stderr, "\n");
948 fprintf(stderr, "rec=");
951 for (z = 0; z < rec->length; z++)
952 fprintf(stderr, "%02X ", rec->data[z]);
953 fprintf(stderr, "\n");
957 if (!SSL_IS_DTLS(ssl)) {
958 for (i = 7; i >= 0; i--) {
967 for (z = 0; z < md_size; z++)
968 fprintf(stderr, "%02X ", md[z]);
969 fprintf(stderr, "\n");
976 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
977 * record in |rec| by updating |rec->length| in constant time.
979 * block_size: the block size of the cipher used to encrypt the record.
981 * 0: (in non-constant time) if the record is publicly invalid.
982 * 1: if the padding was valid
985 int ssl3_cbc_remove_padding(const SSL *s,
987 unsigned block_size, unsigned mac_size)
989 unsigned padding_length, good;
990 const unsigned overhead = 1 /* padding length byte */ + mac_size;
993 * These lengths are all public so we can test them in non-constant time.
995 if (overhead > rec->length)
998 padding_length = rec->data[rec->length - 1];
999 good = constant_time_ge(rec->length, padding_length + overhead);
1000 /* SSLv3 requires that the padding is minimal. */
1001 good &= constant_time_ge(block_size, padding_length + 1);
1002 rec->length -= good & (padding_length + 1);
1003 return constant_time_select_int(good, 1, -1);
1007 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1008 * record in |rec| in constant time and returns 1 if the padding is valid and
1009 * -1 otherwise. It also removes any explicit IV from the start of the record
1010 * without leaking any timing about whether there was enough space after the
1011 * padding was removed.
1013 * block_size: the block size of the cipher used to encrypt the record.
1015 * 0: (in non-constant time) if the record is publicly invalid.
1016 * 1: if the padding was valid
1019 int tls1_cbc_remove_padding(const SSL *s,
1021 unsigned block_size, unsigned mac_size)
1023 unsigned padding_length, good, to_check, i;
1024 const unsigned overhead = 1 /* padding length byte */ + mac_size;
1025 /* Check if version requires explicit IV */
1026 if (SSL_USE_EXPLICIT_IV(s)) {
1028 * These lengths are all public so we can test them in non-constant
1031 if (overhead + block_size > rec->length)
1033 /* We can now safely skip explicit IV */
1034 rec->data += block_size;
1035 rec->input += block_size;
1036 rec->length -= block_size;
1037 rec->orig_len -= block_size;
1038 } else if (overhead > rec->length)
1041 padding_length = rec->data[rec->length - 1];
1044 * NB: if compression is in operation the first packet may not be of even
1045 * length so the padding bug check cannot be performed. This bug
1046 * workaround has been around since SSLeay so hopefully it is either
1047 * fixed now or no buggy implementation supports compression [steve]
1049 if ((s->options & SSL_OP_TLS_BLOCK_PADDING_BUG) && !s->expand) {
1050 /* First packet is even in size, so check */
1051 if ((memcmp(RECORD_LAYER_get_read_sequence(&s->rlayer),
1052 "\0\0\0\0\0\0\0\0", 8) == 0) &&
1053 !(padding_length & 1)) {
1054 s->s3->flags |= TLS1_FLAGS_TLS_PADDING_BUG;
1056 if ((s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG) && padding_length > 0) {
1061 if (EVP_CIPHER_flags(s->enc_read_ctx->cipher) & EVP_CIPH_FLAG_AEAD_CIPHER) {
1062 /* padding is already verified */
1063 rec->length -= padding_length + 1;
1067 good = constant_time_ge(rec->length, overhead + padding_length);
1069 * The padding consists of a length byte at the end of the record and
1070 * then that many bytes of padding, all with the same value as the length
1071 * byte. Thus, with the length byte included, there are i+1 bytes of
1072 * padding. We can't check just |padding_length+1| bytes because that
1073 * leaks decrypted information. Therefore we always have to check the
1074 * maximum amount of padding possible. (Again, the length of the record
1075 * is public information so we can use it.)
1077 to_check = 255; /* maximum amount of padding. */
1078 if (to_check > rec->length - 1)
1079 to_check = rec->length - 1;
1081 for (i = 0; i < to_check; i++) {
1082 unsigned char mask = constant_time_ge_8(padding_length, i);
1083 unsigned char b = rec->data[rec->length - 1 - i];
1085 * The final |padding_length+1| bytes should all have the value
1086 * |padding_length|. Therefore the XOR should be zero.
1088 good &= ~(mask & (padding_length ^ b));
1092 * If any of the final |padding_length+1| bytes had the wrong value, one
1093 * or more of the lower eight bits of |good| will be cleared.
1095 good = constant_time_eq(0xff, good & 0xff);
1096 rec->length -= good & (padding_length + 1);
1098 return constant_time_select_int(good, 1, -1);
1102 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1103 * constant time (independent of the concrete value of rec->length, which may
1104 * vary within a 256-byte window).
1106 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1110 * rec->orig_len >= md_size
1111 * md_size <= EVP_MAX_MD_SIZE
1113 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1114 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1115 * a single or pair of cache-lines, then the variable memory accesses don't
1116 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1117 * not multi-core and are not considered vulnerable to cache-timing attacks.
1119 #define CBC_MAC_ROTATE_IN_PLACE
1121 void ssl3_cbc_copy_mac(unsigned char *out,
1122 const SSL3_RECORD *rec, unsigned md_size)
1124 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1125 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1126 unsigned char *rotated_mac;
1128 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1132 * mac_end is the index of |rec->data| just after the end of the MAC.
1134 unsigned mac_end = rec->length;
1135 unsigned mac_start = mac_end - md_size;
1137 * scan_start contains the number of bytes that we can ignore because the
1138 * MAC's position can only vary by 255 bytes.
1140 unsigned scan_start = 0;
1142 unsigned div_spoiler;
1143 unsigned rotate_offset;
1145 OPENSSL_assert(rec->orig_len >= md_size);
1146 OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
1148 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1149 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1152 /* This information is public so it's safe to branch based on it. */
1153 if (rec->orig_len > md_size + 255 + 1)
1154 scan_start = rec->orig_len - (md_size + 255 + 1);
1156 * div_spoiler contains a multiple of md_size that is used to cause the
1157 * modulo operation to be constant time. Without this, the time varies
1158 * based on the amount of padding when running on Intel chips at least.
1159 * The aim of right-shifting md_size is so that the compiler doesn't
1160 * figure out that it can remove div_spoiler as that would require it to
1161 * prove that md_size is always even, which I hope is beyond it.
1163 div_spoiler = md_size >> 1;
1164 div_spoiler <<= (sizeof(div_spoiler) - 1) * 8;
1165 rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
1167 memset(rotated_mac, 0, md_size);
1168 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1169 unsigned char mac_started = constant_time_ge_8(i, mac_start);
1170 unsigned char mac_ended = constant_time_ge_8(i, mac_end);
1171 unsigned char b = rec->data[i];
1172 rotated_mac[j++] |= b & mac_started & ~mac_ended;
1173 j &= constant_time_lt(j, md_size);
1176 /* Now rotate the MAC */
1177 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1179 for (i = 0; i < md_size; i++) {
1180 /* in case cache-line is 32 bytes, touch second line */
1181 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1182 out[j++] = rotated_mac[rotate_offset++];
1183 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1186 memset(out, 0, md_size);
1187 rotate_offset = md_size - rotate_offset;
1188 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1189 for (i = 0; i < md_size; i++) {
1190 for (j = 0; j < md_size; j++)
1191 out[j] |= rotated_mac[i] & constant_time_eq_8(j, rotate_offset);
1193 rotate_offset &= constant_time_lt(rotate_offset, md_size);
1198 int dtls1_process_record(SSL *s)
1204 unsigned int mac_size;
1205 unsigned char md[EVP_MAX_MD_SIZE];
1207 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1211 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1212 * and we have that many bytes in s->packet
1214 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1217 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1218 * at rr->length bytes, which need to be copied into rr->data by either
1219 * the decryption or by the decompression When the data is 'copied' into
1220 * the rr->data buffer, rr->input will be pointed at the new buffer
1224 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1225 * bytes of encrypted compressed stuff.
1228 /* check is not needed I believe */
1229 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1230 al = SSL_AD_RECORD_OVERFLOW;
1231 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1235 /* decrypt in place in 'rr->input' */
1236 rr->data = rr->input;
1237 rr->orig_len = rr->length;
1239 enc_err = s->method->ssl3_enc->enc(s, 0);
1242 * 0: (in non-constant time) if the record is publically invalid.
1243 * 1: if the padding is valid
1244 * -1: if the padding is invalid
1247 /* For DTLS we simply ignore bad packets. */
1249 RECORD_LAYER_reset_packet_length(&s->rlayer);
1253 printf("dec %d\n", rr->length);
1256 for (z = 0; z < rr->length; z++)
1257 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1262 /* r->length is now the compressed data plus mac */
1263 if ((sess != NULL) &&
1264 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1265 /* s->read_hash != NULL => mac_size != -1 */
1266 unsigned char *mac = NULL;
1267 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1268 mac_size = EVP_MD_CTX_size(s->read_hash);
1269 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1272 * orig_len is the length of the record before any padding was
1273 * removed. This is public information, as is the MAC in use,
1274 * therefore we can safely process the record in a different amount
1275 * of time if it's too short to possibly contain a MAC.
1277 if (rr->orig_len < mac_size ||
1278 /* CBC records must have a padding length byte too. */
1279 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1280 rr->orig_len < mac_size + 1)) {
1281 al = SSL_AD_DECODE_ERROR;
1282 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1286 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1288 * We update the length so that the TLS header bytes can be
1289 * constructed correctly but we need to extract the MAC in
1290 * constant time from within the record, without leaking the
1291 * contents of the padding bytes.
1294 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
1295 rr->length -= mac_size;
1298 * In this case there's no padding, so |rec->orig_len| equals
1299 * |rec->length| and we checked that there's enough bytes for
1302 rr->length -= mac_size;
1303 mac = &rr->data[rr->length];
1306 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
1307 if (i < 0 || mac == NULL
1308 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
1310 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1315 /* decryption failed, silently discard message */
1317 RECORD_LAYER_reset_packet_length(&s->rlayer);
1321 /* r->length is now just compressed */
1322 if (s->expand != NULL) {
1323 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1324 al = SSL_AD_RECORD_OVERFLOW;
1325 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1326 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1329 if (!ssl3_do_uncompress(s)) {
1330 al = SSL_AD_DECOMPRESSION_FAILURE;
1331 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1336 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1337 al = SSL_AD_RECORD_OVERFLOW;
1338 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1344 * So at this point the following is true
1345 * ssl->s3->rrec.type is the type of record
1346 * ssl->s3->rrec.length == number of bytes in record
1347 * ssl->s3->rrec.off == offset to first valid byte
1348 * ssl->s3->rrec.data == where to take bytes from, increment
1352 /* we have pulled in a full packet so zero things */
1353 RECORD_LAYER_reset_packet_length(&s->rlayer);
1357 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1364 * retrieve a buffered record that belongs to the current epoch, ie,
1367 #define dtls1_get_processed_record(s) \
1368 dtls1_retrieve_buffered_record((s), \
1369 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1372 * Call this to get a new input record.
1373 * It will return <= 0 if more data is needed, normally due to an error
1374 * or non-blocking IO.
1375 * When it finishes, one packet has been decoded and can be found in
1376 * ssl->s3->rrec.type - is the type of record
1377 * ssl->s3->rrec.data, - data
1378 * ssl->s3->rrec.length, - number of bytes
1380 /* used only by dtls1_read_bytes */
1381 int dtls1_get_record(SSL *s)
1383 int ssl_major, ssl_minor;
1386 unsigned char *p = NULL;
1387 unsigned short version;
1388 DTLS1_BITMAP *bitmap;
1389 unsigned int is_next_epoch;
1391 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1394 * The epoch may have changed. If so, process all the pending records.
1395 * This is a non-blocking operation.
1397 if (dtls1_process_buffered_records(s) < 0)
1400 /* if we're renegotiating, then there may be buffered records */
1401 if (dtls1_get_processed_record(s))
1404 /* get something from the wire */
1406 /* check if we have the header */
1407 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1408 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1409 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1410 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0);
1411 /* read timeout is handled by dtls1_read_bytes */
1413 return (n); /* error or non-blocking */
1415 /* this packet contained a partial record, dump it */
1416 if (RECORD_LAYER_get_packet_length(&s->rlayer) != DTLS1_RT_HEADER_LENGTH) {
1417 RECORD_LAYER_reset_packet_length(&s->rlayer);
1421 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1423 p = RECORD_LAYER_get_packet(&s->rlayer);
1425 if (s->msg_callback)
1426 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1427 s, s->msg_callback_arg);
1429 /* Pull apart the header into the DTLS1_RECORD */
1433 version = (ssl_major << 8) | ssl_minor;
1435 /* sequence number is 64 bits, with top 2 bytes = epoch */
1438 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1443 /* Lets check version */
1444 if (!s->first_packet) {
1445 if (version != s->version) {
1446 /* unexpected version, silently discard */
1448 RECORD_LAYER_reset_packet_length(&s->rlayer);
1453 if ((version & 0xff00) != (s->version & 0xff00)) {
1454 /* wrong version, silently discard record */
1456 RECORD_LAYER_reset_packet_length(&s->rlayer);
1460 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1461 /* record too long, silently discard it */
1463 RECORD_LAYER_reset_packet_length(&s->rlayer);
1467 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1470 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1473 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1474 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1476 n = ssl3_read_n(s, i, i, 1);
1477 /* this packet contained a partial record, dump it */
1480 RECORD_LAYER_reset_packet_length(&s->rlayer);
1485 * now n == rr->length, and s->packet_length ==
1486 * DTLS1_RT_HEADER_LENGTH + rr->length
1489 /* set state for later operations */
1490 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1492 /* match epochs. NULL means the packet is dropped on the floor */
1493 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1494 if (bitmap == NULL) {
1496 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1497 goto again; /* get another record */
1499 #ifndef OPENSSL_NO_SCTP
1500 /* Only do replay check if no SCTP bio */
1501 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1504 * Check whether this is a repeat, or aged record. Don't check if
1505 * we're listening and this message is a ClientHello. They can look
1506 * as if they're replayed, since they arrive from different
1507 * connections and would be dropped unnecessarily.
1509 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
1510 RECORD_LAYER_get_packet_length(&s->rlayer)
1511 > DTLS1_RT_HEADER_LENGTH &&
1512 RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]
1513 == SSL3_MT_CLIENT_HELLO) &&
1514 !dtls1_record_replay_check(s, bitmap)) {
1516 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1517 goto again; /* get another record */
1519 #ifndef OPENSSL_NO_SCTP
1523 /* just read a 0 length packet */
1524 if (rr->length == 0)
1528 * If this record is from the next epoch (either HM or ALERT), and a
1529 * handshake is currently in progress, buffer it since it cannot be
1530 * processed at this time. However, do not buffer anything while
1533 if (is_next_epoch) {
1534 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
1535 if (dtls1_buffer_record
1536 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1539 /* Mark receipt of record. */
1540 dtls1_record_bitmap_update(s, bitmap);
1543 RECORD_LAYER_reset_packet_length(&s->rlayer);
1547 if (!dtls1_process_record(s)) {
1549 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1550 goto again; /* get another record */
1552 dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */