2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "../ssl_locl.h"
11 #include "internal/constant_time_locl.h"
12 #include <openssl/rand.h>
13 #include "record_locl.h"
14 #include "internal/cryptlib.h"
16 static const unsigned char ssl3_pad_1[48] = {
17 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
18 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
19 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
20 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
21 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
22 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
25 static const unsigned char ssl3_pad_2[48] = {
26 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
27 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
28 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
29 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
30 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
31 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
35 * Clear the contents of an SSL3_RECORD but retain any memory allocated
37 void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
42 for (i = 0; i < num_recs; i++) {
45 memset(&r[i], 0, sizeof(*r));
50 void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
54 for (i = 0; i < num_recs; i++) {
55 OPENSSL_free(r[i].comp);
60 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
62 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
66 * Peeks ahead into "read_ahead" data to see if we have a whole record waiting
67 * for us in the buffer.
69 static int ssl3_record_app_data_waiting(SSL *s)
75 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
77 p = SSL3_BUFFER_get_buf(rbuf);
81 left = SSL3_BUFFER_get_left(rbuf);
83 if (left < SSL3_RT_HEADER_LENGTH)
86 p += SSL3_BUFFER_get_offset(rbuf);
89 * We only check the type and record length, we will sanity check version
92 if (*p != SSL3_RT_APPLICATION_DATA)
98 if (left < SSL3_RT_HEADER_LENGTH + len)
104 int early_data_count_ok(SSL *s, size_t length, size_t overhead, int *al)
106 uint32_t max_early_data = s->max_early_data;
107 SSL_SESSION *sess = s->session;
110 * If we are a client then we always use the max_early_data from the
111 * session/psksession. Otherwise we go with the lowest out of the max early
112 * data set in the session and the configured max_early_data.
114 if (!s->server && sess->ext.max_early_data == 0) {
115 if (!ossl_assert(s->psksession != NULL
116 && s->psksession->ext.max_early_data > 0)) {
117 SSLerr(SSL_F_EARLY_DATA_COUNT_OK, ERR_R_INTERNAL_ERROR);
120 sess = s->psksession;
123 || (s->hit && sess->ext.max_early_data < s->max_early_data))
124 max_early_data = sess->ext.max_early_data;
126 if (max_early_data == 0) {
128 *al = SSL_AD_UNEXPECTED_MESSAGE;
129 SSLerr(SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
133 /* If we are dealing with ciphertext we need to allow for the overhead */
134 max_early_data += overhead;
136 if (s->early_data_count + length > max_early_data) {
138 *al = SSL_AD_UNEXPECTED_MESSAGE;
139 SSLerr(SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
142 s->early_data_count += length;
148 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
149 * will be processed per call to ssl3_get_record. Without this limit an
150 * attacker could send empty records at a faster rate than we can process and
151 * cause ssl3_get_record to loop forever.
153 #define MAX_EMPTY_RECORDS 32
155 #define SSL2_RT_HEADER_LENGTH 2
157 * Call this to get new input records.
158 * It will return <= 0 if more data is needed, normally due to an error
159 * or non-blocking IO.
160 * When it finishes, |numrpipes| records have been decoded. For each record 'i':
161 * rr[i].type - is the type of record
163 * rr[i].length, - number of bytes
164 * Multiple records will only be returned if the record types are all
165 * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
168 /* used only by ssl3_read_bytes */
169 int ssl3_get_record(SSL *s)
172 int enc_err, rret, ret = -1;
175 SSL3_RECORD *rr, *thisrr;
179 unsigned char md[EVP_MAX_MD_SIZE];
180 unsigned int version;
183 size_t num_recs = 0, max_recs, j;
184 PACKET pkt, sslv2pkt;
185 size_t first_rec_len;
187 rr = RECORD_LAYER_get_rrec(&s->rlayer);
188 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
189 max_recs = s->max_pipelines;
195 thisrr = &rr[num_recs];
197 /* check if we have the header */
198 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
199 (RECORD_LAYER_get_packet_length(&s->rlayer)
200 < SSL3_RT_HEADER_LENGTH)) {
204 rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
205 SSL3_BUFFER_get_len(rbuf), 0,
206 num_recs == 0 ? 1 : 0, &n);
208 return rret; /* error or non-blocking */
209 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
211 p = RECORD_LAYER_get_packet(&s->rlayer);
212 if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
213 RECORD_LAYER_get_packet_length(&s->rlayer))) {
214 al = SSL_AD_INTERNAL_ERROR;
215 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
219 if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
220 || !PACKET_get_1(&sslv2pkt, &type)) {
221 al = SSL_AD_DECODE_ERROR;
222 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
226 * The first record received by the server may be a V2ClientHello.
228 if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
229 && (sslv2len & 0x8000) != 0
230 && (type == SSL2_MT_CLIENT_HELLO)) {
234 * |num_recs| here will actually always be 0 because
235 * |num_recs > 0| only ever occurs when we are processing
236 * multiple app data records - which we know isn't the case here
237 * because it is an SSLv2ClientHello. We keep it using
238 * |num_recs| for the sake of consistency
240 thisrr->type = SSL3_RT_HANDSHAKE;
241 thisrr->rec_version = SSL2_VERSION;
243 thisrr->length = sslv2len & 0x7fff;
245 if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
246 - SSL2_RT_HEADER_LENGTH) {
247 al = SSL_AD_RECORD_OVERFLOW;
248 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
252 if (thisrr->length < MIN_SSL2_RECORD_LEN) {
253 al = SSL_AD_DECODE_ERROR;
254 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
258 /* SSLv3+ style record */
260 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
261 s->msg_callback_arg);
263 /* Pull apart the header into the SSL3_RECORD */
264 if (!PACKET_get_1(&pkt, &type)
265 || !PACKET_get_net_2(&pkt, &version)
266 || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
267 al = SSL_AD_DECODE_ERROR;
268 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
272 thisrr->rec_version = version;
275 * Lets check version. In TLSv1.3 we ignore this field. For the
276 * ServerHello after an HRR we haven't actually selected TLSv1.3
277 * yet, but we still treat it as TLSv1.3, so we must check for
280 if (!s->first_packet && !SSL_IS_TLS13(s)
281 && !s->hello_retry_request
282 && version != (unsigned int)s->version) {
283 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
284 if ((s->version & 0xFF00) == (version & 0xFF00)
285 && !s->enc_write_ctx && !s->write_hash) {
286 if (thisrr->type == SSL3_RT_ALERT) {
288 * The record is using an incorrect version number,
289 * but what we've got appears to be an alert. We
290 * haven't read the body yet to check whether its a
291 * fatal or not - but chances are it is. We probably
292 * shouldn't send a fatal alert back. We'll just
298 * Send back error using their minor version number :-)
300 s->version = (unsigned short)version;
302 al = SSL_AD_PROTOCOL_VERSION;
306 if ((version >> 8) != SSL3_VERSION_MAJOR) {
307 if (RECORD_LAYER_is_first_record(&s->rlayer)) {
308 /* Go back to start of packet, look at the five bytes
310 p = RECORD_LAYER_get_packet(&s->rlayer);
311 if (strncmp((char *)p, "GET ", 4) == 0 ||
312 strncmp((char *)p, "POST ", 5) == 0 ||
313 strncmp((char *)p, "HEAD ", 5) == 0 ||
314 strncmp((char *)p, "PUT ", 4) == 0) {
315 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_HTTP_REQUEST);
317 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
318 SSLerr(SSL_F_SSL3_GET_RECORD,
319 SSL_R_HTTPS_PROXY_REQUEST);
323 /* Doesn't look like TLS - don't send an alert */
324 SSLerr(SSL_F_SSL3_GET_RECORD,
325 SSL_R_WRONG_VERSION_NUMBER);
328 SSLerr(SSL_F_SSL3_GET_RECORD,
329 SSL_R_WRONG_VERSION_NUMBER);
330 al = SSL_AD_PROTOCOL_VERSION;
335 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL
336 && thisrr->type != SSL3_RT_APPLICATION_DATA) {
337 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
338 al = SSL_AD_UNEXPECTED_MESSAGE;
343 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
344 al = SSL_AD_RECORD_OVERFLOW;
345 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
350 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
353 if (SSL_IS_TLS13(s)) {
354 if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
355 al = SSL_AD_RECORD_OVERFLOW;
356 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
360 size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
362 #ifndef OPENSSL_NO_COMP
364 * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
365 * does not include the compression overhead anyway.
367 if (s->expand == NULL)
368 len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
371 if (thisrr->length > len) {
372 al = SSL_AD_RECORD_OVERFLOW;
373 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
379 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
380 * Calculate how much more data we need to read for the rest of the
383 if (thisrr->rec_version == SSL2_VERSION) {
384 more = thisrr->length + SSL2_RT_HEADER_LENGTH
385 - SSL3_RT_HEADER_LENGTH;
387 more = thisrr->length;
390 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
392 rret = ssl3_read_n(s, more, more, 1, 0, &n);
394 return rret; /* error or non-blocking io */
397 /* set state for later operations */
398 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
401 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH
402 * + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
403 * + thisrr->length and we have that many bytes in s->packet
405 if (thisrr->rec_version == SSL2_VERSION) {
407 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
410 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
414 * ok, we can now read from 's->packet' data into 'thisrr' thisrr->input
415 * points at thisrr->length bytes, which need to be copied into
416 * thisrr->data by either the decryption or by the decompression When
417 * the data is 'copied' into the thisrr->data buffer, thisrr->input will
418 * be pointed at the new buffer
422 * We now have - encrypted [ MAC [ compressed [ plain ] ] ]
423 * thisrr->length bytes of encrypted compressed stuff.
426 /* decrypt in place in 'thisrr->input' */
427 thisrr->data = thisrr->input;
428 thisrr->orig_len = thisrr->length;
430 /* Mark this record as not read by upper layers yet */
435 /* we have pulled in a full packet so zero things */
436 RECORD_LAYER_reset_packet_length(&s->rlayer);
437 RECORD_LAYER_clear_first_record(&s->rlayer);
438 } while (num_recs < max_recs
439 && thisrr->type == SSL3_RT_APPLICATION_DATA
440 && SSL_USE_EXPLICIT_IV(s)
441 && s->enc_read_ctx != NULL
442 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
443 & EVP_CIPH_FLAG_PIPELINE)
444 && ssl3_record_app_data_waiting(s));
447 * If in encrypt-then-mac mode calculate mac from encrypted record. All
448 * the details below are public so no timing details can leak.
450 if (SSL_READ_ETM(s) && s->read_hash) {
452 /* TODO(size_t): convert this to do size_t properly */
453 imac_size = EVP_MD_CTX_size(s->read_hash);
454 if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
455 al = SSL_AD_INTERNAL_ERROR;
456 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_LIB_EVP);
459 mac_size = (size_t)imac_size;
460 for (j = 0; j < num_recs; j++) {
463 if (thisrr->length < mac_size) {
464 al = SSL_AD_DECODE_ERROR;
465 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
468 thisrr->length -= mac_size;
469 mac = thisrr->data + thisrr->length;
470 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
471 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
472 al = SSL_AD_BAD_RECORD_MAC;
473 SSLerr(SSL_F_SSL3_GET_RECORD,
474 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
480 first_rec_len = rr[0].length;
482 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
486 * 0: (in non-constant time) if the record is publicly invalid.
487 * 1: if the padding is valid
488 * -1: if the padding is invalid
491 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
493 * Valid early_data that we cannot decrypt might fail here as
494 * publicly invalid. We treat it like an empty record.
499 if (!early_data_count_ok(s, thisrr->length,
500 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
505 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
506 RECORD_LAYER_reset_read_sequence(&s->rlayer);
509 al = SSL_AD_DECRYPTION_FAILED;
510 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
514 printf("dec %"OSSLzu"\n", rr[0].length);
517 for (z = 0; z < rr[0].length; z++)
518 printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
523 /* r->length is now the compressed data plus mac */
524 if ((sess != NULL) &&
525 (s->enc_read_ctx != NULL) &&
526 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
527 /* s->read_hash != NULL => mac_size != -1 */
528 unsigned char *mac = NULL;
529 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
531 mac_size = EVP_MD_CTX_size(s->read_hash);
532 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
533 al = SSL_AD_INTERNAL_ERROR;
534 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
538 for (j = 0; j < num_recs; j++) {
541 * orig_len is the length of the record before any padding was
542 * removed. This is public information, as is the MAC in use,
543 * therefore we can safely process the record in a different amount
544 * of time if it's too short to possibly contain a MAC.
546 if (thisrr->orig_len < mac_size ||
547 /* CBC records must have a padding length byte too. */
548 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
549 thisrr->orig_len < mac_size + 1)) {
550 al = SSL_AD_DECODE_ERROR;
551 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
555 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
557 * We update the length so that the TLS header bytes can be
558 * constructed correctly but we need to extract the MAC in
559 * constant time from within the record, without leaking the
560 * contents of the padding bytes.
563 if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
564 al = SSL_AD_INTERNAL_ERROR;
565 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
568 thisrr->length -= mac_size;
571 * In this case there's no padding, so |rec->orig_len| equals
572 * |rec->length| and we checked that there's enough bytes for
575 thisrr->length -= mac_size;
576 mac = &thisrr->data[thisrr->length];
579 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
580 if (i == 0 || mac == NULL
581 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
583 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
589 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
591 * We assume this is unreadable early_data - we treat it like an
596 * The record length may have been modified by the mac check above
597 * so we use the previously saved value
599 if (!early_data_count_ok(s, first_rec_len,
600 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
606 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
607 RECORD_LAYER_reset_read_sequence(&s->rlayer);
611 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
612 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
613 * failure is directly visible from the ciphertext anyway, we should
614 * not reveal which kind of error occurred -- this might become
615 * visible to an attacker (e.g. via a logfile)
617 al = SSL_AD_BAD_RECORD_MAC;
618 SSLerr(SSL_F_SSL3_GET_RECORD,
619 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
623 for (j = 0; j < num_recs; j++) {
626 /* thisrr->length is now just compressed */
627 if (s->expand != NULL) {
628 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
629 al = SSL_AD_RECORD_OVERFLOW;
630 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
633 if (!ssl3_do_uncompress(s, thisrr)) {
634 al = SSL_AD_DECOMPRESSION_FAILURE;
635 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
640 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
643 if (thisrr->length == 0
644 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
645 al = SSL_AD_UNEXPECTED_MESSAGE;
646 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
650 /* Strip trailing padding */
651 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
655 thisrr->length = end;
656 thisrr->type = thisrr->data[end];
657 if (thisrr->type != SSL3_RT_APPLICATION_DATA
658 && thisrr->type != SSL3_RT_ALERT
659 && thisrr->type != SSL3_RT_HANDSHAKE) {
660 al = SSL_AD_UNEXPECTED_MESSAGE;
661 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
665 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
666 &thisrr->data[end], 1, s, s->msg_callback_arg);
670 * TLSv1.3 alert and handshake records are required to be non-zero in
674 && (thisrr->type == SSL3_RT_HANDSHAKE
675 || thisrr->type == SSL3_RT_ALERT)
676 && thisrr->length == 0) {
677 al = SSL_AD_UNEXPECTED_MESSAGE;
678 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_LENGTH);
682 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
683 al = SSL_AD_RECORD_OVERFLOW;
684 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
690 * So at this point the following is true
691 * thisrr->type is the type of record
692 * thisrr->length == number of bytes in record
693 * thisrr->off == offset to first valid byte
694 * thisrr->data == where to take bytes from, increment after use :-).
697 /* just read a 0 length packet */
698 if (thisrr->length == 0) {
699 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
700 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
701 > MAX_EMPTY_RECORDS) {
702 al = SSL_AD_UNEXPECTED_MESSAGE;
703 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
707 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
711 if (s->early_data_state == SSL_EARLY_DATA_READING) {
713 if (thisrr->type == SSL3_RT_APPLICATION_DATA
714 && !early_data_count_ok(s, thisrr->length, 0, &al))
718 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
722 ssl3_send_alert(s, SSL3_AL_FATAL, al);
727 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
729 #ifndef OPENSSL_NO_COMP
732 if (rr->comp == NULL) {
733 rr->comp = (unsigned char *)
734 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
736 if (rr->comp == NULL)
739 /* TODO(size_t): Convert this call */
740 i = COMP_expand_block(ssl->expand, rr->comp,
741 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
751 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
753 #ifndef OPENSSL_NO_COMP
756 /* TODO(size_t): Convert this call */
757 i = COMP_compress_block(ssl->compress, wr->data,
758 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
759 wr->input, (int)wr->length);
765 wr->input = wr->data;
771 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
774 * 0: (in non-constant time) if the record is publically invalid (i.e. too
776 * 1: if the record's padding is valid / the encryption was successful.
777 * -1: if the record's padding is invalid or, if sending, an internal error
780 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
785 size_t bs, mac_size = 0;
787 const EVP_CIPHER *enc;
791 * We shouldn't ever be called with more than one record in the SSLv3 case
796 ds = s->enc_write_ctx;
797 if (s->enc_write_ctx == NULL)
800 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
802 ds = s->enc_read_ctx;
803 if (s->enc_read_ctx == NULL)
806 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
809 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
810 memmove(rec->data, rec->input, rec->length);
811 rec->input = rec->data;
814 /* TODO(size_t): Convert this call */
815 bs = EVP_CIPHER_CTX_block_size(ds);
819 if ((bs != 1) && sending) {
822 /* we need to add 'i-1' padding bytes */
825 * the last of these zero bytes will be overwritten with the
828 memset(&rec->input[rec->length], 0, i);
830 rec->input[l - 1] = (unsigned char)(i - 1);
834 if (l == 0 || l % bs != 0)
836 /* otherwise, rec->length >= bs */
839 /* TODO(size_t): Convert this call */
840 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
843 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
844 /* TODO(size_t): convert me */
845 imac_size = EVP_MD_CTX_size(s->read_hash);
848 mac_size = (size_t)imac_size;
850 if ((bs != 1) && !sending)
851 return ssl3_cbc_remove_padding(rec, bs, mac_size);
856 #define MAX_PADDING 256
858 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
861 * 0: (in non-constant time) if the record is publically invalid (i.e. too
863 * 1: if the record's padding is valid / the encryption was successful.
864 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
865 * an internal error occurred.
867 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
870 size_t reclen[SSL_MAX_PIPELINES];
871 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
872 int i, pad = 0, ret, tmpr;
873 size_t bs, mac_size = 0, ctr, padnum, loop;
874 unsigned char padval;
876 const EVP_CIPHER *enc;
882 if (EVP_MD_CTX_md(s->write_hash)) {
883 int n = EVP_MD_CTX_size(s->write_hash);
884 if (!ossl_assert(n >= 0)) {
885 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
889 ds = s->enc_write_ctx;
890 if (s->enc_write_ctx == NULL)
894 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
895 /* For TLSv1.1 and later explicit IV */
896 if (SSL_USE_EXPLICIT_IV(s)
897 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
898 ivlen = EVP_CIPHER_iv_length(enc);
902 for (ctr = 0; ctr < n_recs; ctr++) {
903 if (recs[ctr].data != recs[ctr].input) {
905 * we can't write into the input stream: Can this ever
908 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
910 } else if (ssl_randbytes(s, recs[ctr].input, ivlen) <= 0) {
911 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
918 if (EVP_MD_CTX_md(s->read_hash)) {
919 int n = EVP_MD_CTX_size(s->read_hash);
920 if (!ossl_assert(n >= 0)) {
921 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
925 ds = s->enc_read_ctx;
926 if (s->enc_read_ctx == NULL)
929 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
932 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
933 for (ctr = 0; ctr < n_recs; ctr++) {
934 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
935 recs[ctr].input = recs[ctr].data;
939 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
942 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
943 & EVP_CIPH_FLAG_PIPELINE)) {
945 * We shouldn't have been called with pipeline data if the
946 * cipher doesn't support pipelining
948 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
952 for (ctr = 0; ctr < n_recs; ctr++) {
953 reclen[ctr] = recs[ctr].length;
955 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
956 & EVP_CIPH_FLAG_AEAD_CIPHER) {
959 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
960 : RECORD_LAYER_get_read_sequence(&s->rlayer);
962 if (SSL_IS_DTLS(s)) {
963 /* DTLS does not support pipelining */
964 unsigned char dtlsseq[9], *p = dtlsseq;
966 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
967 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
968 memcpy(p, &seq[2], 6);
969 memcpy(buf[ctr], dtlsseq, 8);
971 memcpy(buf[ctr], seq, 8);
972 for (i = 7; i >= 0; i--) { /* increment */
979 buf[ctr][8] = recs[ctr].type;
980 buf[ctr][9] = (unsigned char)(s->version >> 8);
981 buf[ctr][10] = (unsigned char)(s->version);
982 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
983 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
984 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
985 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
991 recs[ctr].length += pad;
994 } else if ((bs != 1) && sending) {
995 padnum = bs - (reclen[ctr] % bs);
997 /* Add weird padding of upto 256 bytes */
999 if (padnum > MAX_PADDING)
1001 /* we need to add 'padnum' padding bytes of value padval */
1002 padval = (unsigned char)(padnum - 1);
1003 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
1004 recs[ctr].input[loop] = padval;
1005 reclen[ctr] += padnum;
1006 recs[ctr].length += padnum;
1010 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
1015 unsigned char *data[SSL_MAX_PIPELINES];
1017 /* Set the output buffers */
1018 for (ctr = 0; ctr < n_recs; ctr++) {
1019 data[ctr] = recs[ctr].data;
1021 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
1022 (int)n_recs, data) <= 0) {
1023 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1025 /* Set the input buffers */
1026 for (ctr = 0; ctr < n_recs; ctr++) {
1027 data[ctr] = recs[ctr].input;
1029 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
1030 (int)n_recs, data) <= 0
1031 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1032 (int)n_recs, reclen) <= 0) {
1033 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1038 /* TODO(size_t): Convert this call */
1039 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1040 (unsigned int)reclen[0]);
1041 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1042 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1045 return -1; /* AEAD can fail to verify MAC */
1047 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1048 for (ctr = 0; ctr < n_recs; ctr++) {
1049 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1050 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1051 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1053 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1054 for (ctr = 0; ctr < n_recs; ctr++) {
1055 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1056 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1057 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1063 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1064 imac_size = EVP_MD_CTX_size(s->read_hash);
1067 mac_size = (size_t)imac_size;
1069 if ((bs != 1) && !sending) {
1071 for (ctr = 0; ctr < n_recs; ctr++) {
1072 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1074 * If tmpret == 0 then this means publicly invalid so we can
1075 * short circuit things here. Otherwise we must respect constant
1080 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1084 if (pad && !sending) {
1085 for (ctr = 0; ctr < n_recs; ctr++) {
1086 recs[ctr].length -= pad;
1093 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1095 unsigned char *mac_sec, *seq;
1096 const EVP_MD_CTX *hash;
1097 unsigned char *p, rec_char;
1103 mac_sec = &(ssl->s3->write_mac_secret[0]);
1104 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1105 hash = ssl->write_hash;
1107 mac_sec = &(ssl->s3->read_mac_secret[0]);
1108 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1109 hash = ssl->read_hash;
1112 t = EVP_MD_CTX_size(hash);
1116 npad = (48 / md_size) * md_size;
1119 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1120 ssl3_cbc_record_digest_supported(hash)) {
1122 * This is a CBC-encrypted record. We must avoid leaking any
1123 * timing-side channel information about how many blocks of data we
1124 * are hashing because that gives an attacker a timing-oracle.
1128 * npad is, at most, 48 bytes and that's with MD5:
1129 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1131 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1132 * goes up 4, but npad goes down by 8, resulting in a smaller
1135 unsigned char header[75];
1137 memcpy(header + j, mac_sec, md_size);
1139 memcpy(header + j, ssl3_pad_1, npad);
1141 memcpy(header + j, seq, 8);
1143 header[j++] = rec->type;
1144 header[j++] = (unsigned char)(rec->length >> 8);
1145 header[j++] = (unsigned char)(rec->length & 0xff);
1147 /* Final param == is SSLv3 */
1148 if (ssl3_cbc_digest_record(hash,
1151 rec->length + md_size, rec->orig_len,
1152 mac_sec, md_size, 1) <= 0)
1155 unsigned int md_size_u;
1156 /* Chop the digest off the end :-) */
1157 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1162 rec_char = rec->type;
1164 s2n(rec->length, p);
1165 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1166 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1167 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1168 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1169 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1170 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1171 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1172 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1173 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1174 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1175 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1176 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1177 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1178 EVP_MD_CTX_reset(md_ctx);
1182 EVP_MD_CTX_free(md_ctx);
1185 ssl3_record_sequence_update(seq);
1189 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1195 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1196 unsigned char header[13];
1197 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1198 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1202 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1203 hash = ssl->write_hash;
1205 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1206 hash = ssl->read_hash;
1209 t = EVP_MD_CTX_size(hash);
1210 if (!ossl_assert(t >= 0))
1214 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1218 hmac = EVP_MD_CTX_new();
1219 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1224 if (SSL_IS_DTLS(ssl)) {
1225 unsigned char dtlsseq[8], *p = dtlsseq;
1227 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1228 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1229 memcpy(p, &seq[2], 6);
1231 memcpy(header, dtlsseq, 8);
1233 memcpy(header, seq, 8);
1235 header[8] = rec->type;
1236 header[9] = (unsigned char)(ssl->version >> 8);
1237 header[10] = (unsigned char)(ssl->version);
1238 header[11] = (unsigned char)(rec->length >> 8);
1239 header[12] = (unsigned char)(rec->length & 0xff);
1241 if (!sending && !SSL_READ_ETM(ssl) &&
1242 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1243 ssl3_cbc_record_digest_supported(mac_ctx)) {
1245 * This is a CBC-encrypted record. We must avoid leaking any
1246 * timing-side channel information about how many blocks of data we
1247 * are hashing because that gives an attacker a timing-oracle.
1249 /* Final param == not SSLv3 */
1250 if (ssl3_cbc_digest_record(mac_ctx,
1253 rec->length + md_size, rec->orig_len,
1254 ssl->s3->read_mac_secret,
1255 ssl->s3->read_mac_secret_size, 0) <= 0) {
1256 EVP_MD_CTX_free(hmac);
1260 /* TODO(size_t): Convert these calls */
1261 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1262 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1263 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1264 EVP_MD_CTX_free(hmac);
1269 EVP_MD_CTX_free(hmac);
1272 fprintf(stderr, "seq=");
1275 for (z = 0; z < 8; z++)
1276 fprintf(stderr, "%02X ", seq[z]);
1277 fprintf(stderr, "\n");
1279 fprintf(stderr, "rec=");
1282 for (z = 0; z < rec->length; z++)
1283 fprintf(stderr, "%02X ", rec->data[z]);
1284 fprintf(stderr, "\n");
1288 if (!SSL_IS_DTLS(ssl)) {
1289 for (i = 7; i >= 0; i--) {
1298 for (z = 0; z < md_size; z++)
1299 fprintf(stderr, "%02X ", md[z]);
1300 fprintf(stderr, "\n");
1307 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1308 * record in |rec| by updating |rec->length| in constant time.
1310 * block_size: the block size of the cipher used to encrypt the record.
1312 * 0: (in non-constant time) if the record is publicly invalid.
1313 * 1: if the padding was valid
1316 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1317 size_t block_size, size_t mac_size)
1319 size_t padding_length;
1321 const size_t overhead = 1 /* padding length byte */ + mac_size;
1324 * These lengths are all public so we can test them in non-constant time.
1326 if (overhead > rec->length)
1329 padding_length = rec->data[rec->length - 1];
1330 good = constant_time_ge_s(rec->length, padding_length + overhead);
1331 /* SSLv3 requires that the padding is minimal. */
1332 good &= constant_time_ge_s(block_size, padding_length + 1);
1333 rec->length -= good & (padding_length + 1);
1334 return constant_time_select_int_s(good, 1, -1);
1338 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1339 * record in |rec| in constant time and returns 1 if the padding is valid and
1340 * -1 otherwise. It also removes any explicit IV from the start of the record
1341 * without leaking any timing about whether there was enough space after the
1342 * padding was removed.
1344 * block_size: the block size of the cipher used to encrypt the record.
1346 * 0: (in non-constant time) if the record is publicly invalid.
1347 * 1: if the padding was valid
1350 int tls1_cbc_remove_padding(const SSL *s,
1352 size_t block_size, size_t mac_size)
1355 size_t padding_length, to_check, i;
1356 const size_t overhead = 1 /* padding length byte */ + mac_size;
1357 /* Check if version requires explicit IV */
1358 if (SSL_USE_EXPLICIT_IV(s)) {
1360 * These lengths are all public so we can test them in non-constant
1363 if (overhead + block_size > rec->length)
1365 /* We can now safely skip explicit IV */
1366 rec->data += block_size;
1367 rec->input += block_size;
1368 rec->length -= block_size;
1369 rec->orig_len -= block_size;
1370 } else if (overhead > rec->length)
1373 padding_length = rec->data[rec->length - 1];
1375 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1376 EVP_CIPH_FLAG_AEAD_CIPHER) {
1377 /* padding is already verified */
1378 rec->length -= padding_length + 1;
1382 good = constant_time_ge_s(rec->length, overhead + padding_length);
1384 * The padding consists of a length byte at the end of the record and
1385 * then that many bytes of padding, all with the same value as the length
1386 * byte. Thus, with the length byte included, there are i+1 bytes of
1387 * padding. We can't check just |padding_length+1| bytes because that
1388 * leaks decrypted information. Therefore we always have to check the
1389 * maximum amount of padding possible. (Again, the length of the record
1390 * is public information so we can use it.)
1392 to_check = 256; /* maximum amount of padding, inc length byte. */
1393 if (to_check > rec->length)
1394 to_check = rec->length;
1396 for (i = 0; i < to_check; i++) {
1397 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1398 unsigned char b = rec->data[rec->length - 1 - i];
1400 * The final |padding_length+1| bytes should all have the value
1401 * |padding_length|. Therefore the XOR should be zero.
1403 good &= ~(mask & (padding_length ^ b));
1407 * If any of the final |padding_length+1| bytes had the wrong value, one
1408 * or more of the lower eight bits of |good| will be cleared.
1410 good = constant_time_eq_s(0xff, good & 0xff);
1411 rec->length -= good & (padding_length + 1);
1413 return constant_time_select_int_s(good, 1, -1);
1417 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1418 * constant time (independent of the concrete value of rec->length, which may
1419 * vary within a 256-byte window).
1421 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1425 * rec->orig_len >= md_size
1426 * md_size <= EVP_MAX_MD_SIZE
1428 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1429 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1430 * a single or pair of cache-lines, then the variable memory accesses don't
1431 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1432 * not multi-core and are not considered vulnerable to cache-timing attacks.
1434 #define CBC_MAC_ROTATE_IN_PLACE
1436 int ssl3_cbc_copy_mac(unsigned char *out,
1437 const SSL3_RECORD *rec, size_t md_size)
1439 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1440 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1441 unsigned char *rotated_mac;
1443 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1447 * mac_end is the index of |rec->data| just after the end of the MAC.
1449 size_t mac_end = rec->length;
1450 size_t mac_start = mac_end - md_size;
1453 * scan_start contains the number of bytes that we can ignore because the
1454 * MAC's position can only vary by 255 bytes.
1456 size_t scan_start = 0;
1458 size_t rotate_offset;
1460 if (!ossl_assert(rec->orig_len >= md_size
1461 && md_size <= EVP_MAX_MD_SIZE))
1464 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1465 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1468 /* This information is public so it's safe to branch based on it. */
1469 if (rec->orig_len > md_size + 255 + 1)
1470 scan_start = rec->orig_len - (md_size + 255 + 1);
1474 memset(rotated_mac, 0, md_size);
1475 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1476 size_t mac_started = constant_time_eq_s(i, mac_start);
1477 size_t mac_ended = constant_time_lt_s(i, mac_end);
1478 unsigned char b = rec->data[i];
1480 in_mac |= mac_started;
1481 in_mac &= mac_ended;
1482 rotate_offset |= j & mac_started;
1483 rotated_mac[j++] |= b & in_mac;
1484 j &= constant_time_lt_s(j, md_size);
1487 /* Now rotate the MAC */
1488 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1490 for (i = 0; i < md_size; i++) {
1491 /* in case cache-line is 32 bytes, touch second line */
1492 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1493 out[j++] = rotated_mac[rotate_offset++];
1494 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1497 memset(out, 0, md_size);
1498 rotate_offset = md_size - rotate_offset;
1499 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1500 for (i = 0; i < md_size; i++) {
1501 for (j = 0; j < md_size; j++)
1502 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1504 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1511 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1519 unsigned char md[EVP_MAX_MD_SIZE];
1521 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1525 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1526 * and we have that many bytes in s->packet
1528 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1531 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1532 * at rr->length bytes, which need to be copied into rr->data by either
1533 * the decryption or by the decompression When the data is 'copied' into
1534 * the rr->data buffer, rr->input will be pointed at the new buffer
1538 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1539 * bytes of encrypted compressed stuff.
1542 /* check is not needed I believe */
1543 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1544 al = SSL_AD_RECORD_OVERFLOW;
1545 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1549 /* decrypt in place in 'rr->input' */
1550 rr->data = rr->input;
1551 rr->orig_len = rr->length;
1553 if (SSL_READ_ETM(s) && s->read_hash) {
1555 mac_size = EVP_MD_CTX_size(s->read_hash);
1556 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1557 al = SSL_AD_INTERNAL_ERROR;
1558 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1561 if (rr->orig_len < mac_size) {
1562 al = SSL_AD_DECODE_ERROR;
1563 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1566 rr->length -= mac_size;
1567 mac = rr->data + rr->length;
1568 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1569 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1570 al = SSL_AD_BAD_RECORD_MAC;
1571 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1572 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1577 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1580 * 0: (in non-constant time) if the record is publically invalid.
1581 * 1: if the padding is valid
1582 * -1: if the padding is invalid
1585 /* For DTLS we simply ignore bad packets. */
1587 RECORD_LAYER_reset_packet_length(&s->rlayer);
1591 printf("dec %ld\n", rr->length);
1594 for (z = 0; z < rr->length; z++)
1595 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1600 /* r->length is now the compressed data plus mac */
1601 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1602 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1603 /* s->read_hash != NULL => mac_size != -1 */
1604 unsigned char *mac = NULL;
1605 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1607 /* TODO(size_t): Convert this to do size_t properly */
1608 imac_size = EVP_MD_CTX_size(s->read_hash);
1609 if (imac_size < 0) {
1610 al = SSL_AD_INTERNAL_ERROR;
1611 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1614 mac_size = (size_t)imac_size;
1615 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1616 al = SSL_AD_INTERNAL_ERROR;
1617 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1622 * orig_len is the length of the record before any padding was
1623 * removed. This is public information, as is the MAC in use,
1624 * therefore we can safely process the record in a different amount
1625 * of time if it's too short to possibly contain a MAC.
1627 if (rr->orig_len < mac_size ||
1628 /* CBC records must have a padding length byte too. */
1629 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1630 rr->orig_len < mac_size + 1)) {
1631 al = SSL_AD_DECODE_ERROR;
1632 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1636 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1638 * We update the length so that the TLS header bytes can be
1639 * constructed correctly but we need to extract the MAC in
1640 * constant time from within the record, without leaking the
1641 * contents of the padding bytes.
1644 if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
1645 al = SSL_AD_INTERNAL_ERROR;
1646 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1649 rr->length -= mac_size;
1652 * In this case there's no padding, so |rec->orig_len| equals
1653 * |rec->length| and we checked that there's enough bytes for
1656 rr->length -= mac_size;
1657 mac = &rr->data[rr->length];
1660 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1661 if (i == 0 || mac == NULL
1662 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1664 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1669 /* decryption failed, silently discard message */
1671 RECORD_LAYER_reset_packet_length(&s->rlayer);
1675 /* r->length is now just compressed */
1676 if (s->expand != NULL) {
1677 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1678 al = SSL_AD_RECORD_OVERFLOW;
1679 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1680 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1683 if (!ssl3_do_uncompress(s, rr)) {
1684 al = SSL_AD_DECOMPRESSION_FAILURE;
1685 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1690 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1691 al = SSL_AD_RECORD_OVERFLOW;
1692 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1698 * So at this point the following is true
1699 * ssl->s3->rrec.type is the type of record
1700 * ssl->s3->rrec.length == number of bytes in record
1701 * ssl->s3->rrec.off == offset to first valid byte
1702 * ssl->s3->rrec.data == where to take bytes from, increment
1706 /* we have pulled in a full packet so zero things */
1707 RECORD_LAYER_reset_packet_length(&s->rlayer);
1709 /* Mark receipt of record. */
1710 dtls1_record_bitmap_update(s, bitmap);
1715 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1721 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1723 #define dtls1_get_processed_record(s) \
1724 dtls1_retrieve_buffered_record((s), \
1725 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1728 * Call this to get a new input record.
1729 * It will return <= 0 if more data is needed, normally due to an error
1730 * or non-blocking IO.
1731 * When it finishes, one packet has been decoded and can be found in
1732 * ssl->s3->rrec.type - is the type of record
1733 * ssl->s3->rrec.data, - data
1734 * ssl->s3->rrec.length, - number of bytes
1736 /* used only by dtls1_read_bytes */
1737 int dtls1_get_record(SSL *s)
1739 int ssl_major, ssl_minor;
1743 unsigned char *p = NULL;
1744 unsigned short version;
1745 DTLS1_BITMAP *bitmap;
1746 unsigned int is_next_epoch;
1748 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1752 * The epoch may have changed. If so, process all the pending records.
1753 * This is a non-blocking operation.
1755 if (!dtls1_process_buffered_records(s))
1758 /* if we're renegotiating, then there may be buffered records */
1759 if (dtls1_get_processed_record(s))
1762 /* get something from the wire */
1764 /* check if we have the header */
1765 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1766 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1767 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1768 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1769 /* read timeout is handled by dtls1_read_bytes */
1771 return rret; /* error or non-blocking */
1773 /* this packet contained a partial record, dump it */
1774 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1775 DTLS1_RT_HEADER_LENGTH) {
1776 RECORD_LAYER_reset_packet_length(&s->rlayer);
1780 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1782 p = RECORD_LAYER_get_packet(&s->rlayer);
1784 if (s->msg_callback)
1785 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1786 s, s->msg_callback_arg);
1788 /* Pull apart the header into the DTLS1_RECORD */
1792 version = (ssl_major << 8) | ssl_minor;
1794 /* sequence number is 64 bits, with top 2 bytes = epoch */
1797 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1802 /* Lets check version */
1803 if (!s->first_packet) {
1804 if (version != s->version) {
1805 /* unexpected version, silently discard */
1807 RECORD_LAYER_reset_packet_length(&s->rlayer);
1812 if ((version & 0xff00) != (s->version & 0xff00)) {
1813 /* wrong version, silently discard record */
1815 RECORD_LAYER_reset_packet_length(&s->rlayer);
1819 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1820 /* record too long, silently discard it */
1822 RECORD_LAYER_reset_packet_length(&s->rlayer);
1826 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1829 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1832 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1833 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1835 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1836 /* this packet contained a partial record, dump it */
1837 if (rret <= 0 || n != more) {
1839 RECORD_LAYER_reset_packet_length(&s->rlayer);
1844 * now n == rr->length, and s->packet_length ==
1845 * DTLS1_RT_HEADER_LENGTH + rr->length
1848 /* set state for later operations */
1849 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1851 /* match epochs. NULL means the packet is dropped on the floor */
1852 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1853 if (bitmap == NULL) {
1855 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1856 goto again; /* get another record */
1858 #ifndef OPENSSL_NO_SCTP
1859 /* Only do replay check if no SCTP bio */
1860 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1862 /* Check whether this is a repeat, or aged record. */
1864 * TODO: Does it make sense to have replay protection in epoch 0 where
1865 * we have no integrity negotiated yet?
1867 if (!dtls1_record_replay_check(s, bitmap)) {
1869 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1870 goto again; /* get another record */
1872 #ifndef OPENSSL_NO_SCTP
1876 /* just read a 0 length packet */
1877 if (rr->length == 0)
1881 * If this record is from the next epoch (either HM or ALERT), and a
1882 * handshake is currently in progress, buffer it since it cannot be
1883 * processed at this time.
1885 if (is_next_epoch) {
1886 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1887 if (dtls1_buffer_record
1888 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1893 RECORD_LAYER_reset_packet_length(&s->rlayer);
1897 if (!dtls1_process_record(s, bitmap)) {
1899 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1900 goto again; /* get another record */