2 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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_local.h"
11 #include "internal/constant_time.h"
12 #include <openssl/trace.h>
13 #include <openssl/rand.h>
14 #include "record_local.h"
15 #include "internal/cryptlib.h"
17 static const unsigned char ssl3_pad_1[48] = {
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,
23 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
26 static const unsigned char ssl3_pad_2[48] = {
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,
32 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
36 * Clear the contents of an SSL3_RECORD but retain any memory allocated
38 void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
43 for (i = 0; i < num_recs; i++) {
46 memset(&r[i], 0, sizeof(*r));
51 void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
55 for (i = 0; i < num_recs; i++) {
56 OPENSSL_free(r[i].comp);
61 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
63 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
67 * Peeks ahead into "read_ahead" data to see if we have a whole record waiting
68 * for us in the buffer.
70 static int ssl3_record_app_data_waiting(SSL *s)
76 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
78 p = SSL3_BUFFER_get_buf(rbuf);
82 left = SSL3_BUFFER_get_left(rbuf);
84 if (left < SSL3_RT_HEADER_LENGTH)
87 p += SSL3_BUFFER_get_offset(rbuf);
90 * We only check the type and record length, we will sanity check version
93 if (*p != SSL3_RT_APPLICATION_DATA)
99 if (left < SSL3_RT_HEADER_LENGTH + len)
105 int early_data_count_ok(SSL *s, size_t length, size_t overhead, int send)
107 uint32_t max_early_data;
108 SSL_SESSION *sess = s->session;
111 * If we are a client then we always use the max_early_data from the
112 * session/psksession. Otherwise we go with the lowest out of the max early
113 * data set in the session and the configured max_early_data.
115 if (!s->server && sess->ext.max_early_data == 0) {
116 if (!ossl_assert(s->psksession != NULL
117 && s->psksession->ext.max_early_data > 0)) {
118 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_EARLY_DATA_COUNT_OK,
119 ERR_R_INTERNAL_ERROR);
122 sess = s->psksession;
126 max_early_data = sess->ext.max_early_data;
127 else if (s->ext.early_data != SSL_EARLY_DATA_ACCEPTED)
128 max_early_data = s->recv_max_early_data;
130 max_early_data = s->recv_max_early_data < sess->ext.max_early_data
131 ? s->recv_max_early_data : sess->ext.max_early_data;
133 if (max_early_data == 0) {
134 SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
135 SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
139 /* If we are dealing with ciphertext we need to allow for the overhead */
140 max_early_data += overhead;
142 if (s->early_data_count + length > max_early_data) {
143 SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
144 SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
147 s->early_data_count += length;
153 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
154 * will be processed per call to ssl3_get_record. Without this limit an
155 * attacker could send empty records at a faster rate than we can process and
156 * cause ssl3_get_record to loop forever.
158 #define MAX_EMPTY_RECORDS 32
160 #define SSL2_RT_HEADER_LENGTH 2
162 * Call this to get new input records.
163 * It will return <= 0 if more data is needed, normally due to an error
164 * or non-blocking IO.
165 * When it finishes, |numrpipes| records have been decoded. For each record 'i':
166 * rr[i].type - is the type of record
168 * rr[i].length, - number of bytes
169 * Multiple records will only be returned if the record types are all
170 * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
173 /* used only by ssl3_read_bytes */
174 int ssl3_get_record(SSL *s)
179 SSL3_RECORD *rr, *thisrr;
183 unsigned char md[EVP_MAX_MD_SIZE];
184 unsigned int version;
187 size_t num_recs = 0, max_recs, j;
188 PACKET pkt, sslv2pkt;
189 size_t first_rec_len;
192 rr = RECORD_LAYER_get_rrec(&s->rlayer);
193 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
194 is_ktls_left = (rbuf->left > 0);
195 max_recs = s->max_pipelines;
201 thisrr = &rr[num_recs];
203 /* check if we have the header */
204 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
205 (RECORD_LAYER_get_packet_length(&s->rlayer)
206 < SSL3_RT_HEADER_LENGTH)) {
210 rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
211 SSL3_BUFFER_get_len(rbuf), 0,
212 num_recs == 0 ? 1 : 0, &n);
214 #ifndef OPENSSL_NO_KTLS
215 if (!BIO_get_ktls_recv(s->rbio))
216 return rret; /* error or non-blocking */
219 SSLfatal(s, SSL_AD_BAD_RECORD_MAC,
220 SSL_F_SSL3_GET_RECORD,
221 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
224 SSLfatal(s, SSL_AD_RECORD_OVERFLOW,
225 SSL_F_SSL3_GET_RECORD,
226 SSL_R_PACKET_LENGTH_TOO_LONG);
229 SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
230 SSL_F_SSL3_GET_RECORD,
231 SSL_R_WRONG_VERSION_NUMBER);
239 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
241 p = RECORD_LAYER_get_packet(&s->rlayer);
242 if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
243 RECORD_LAYER_get_packet_length(&s->rlayer))) {
244 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
245 ERR_R_INTERNAL_ERROR);
249 if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
250 || !PACKET_get_1(&sslv2pkt, &type)) {
251 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
252 ERR_R_INTERNAL_ERROR);
256 * The first record received by the server may be a V2ClientHello.
258 if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
259 && (sslv2len & 0x8000) != 0
260 && (type == SSL2_MT_CLIENT_HELLO)) {
264 * |num_recs| here will actually always be 0 because
265 * |num_recs > 0| only ever occurs when we are processing
266 * multiple app data records - which we know isn't the case here
267 * because it is an SSLv2ClientHello. We keep it using
268 * |num_recs| for the sake of consistency
270 thisrr->type = SSL3_RT_HANDSHAKE;
271 thisrr->rec_version = SSL2_VERSION;
273 thisrr->length = sslv2len & 0x7fff;
275 if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
276 - SSL2_RT_HEADER_LENGTH) {
277 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
278 SSL_R_PACKET_LENGTH_TOO_LONG);
282 if (thisrr->length < MIN_SSL2_RECORD_LEN) {
283 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
284 SSL_R_LENGTH_TOO_SHORT);
288 /* SSLv3+ style record */
290 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
291 s->msg_callback_arg);
293 /* Pull apart the header into the SSL3_RECORD */
294 if (!PACKET_get_1(&pkt, &type)
295 || !PACKET_get_net_2(&pkt, &version)
296 || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
297 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
298 ERR_R_INTERNAL_ERROR);
302 thisrr->rec_version = version;
305 * Lets check version. In TLSv1.3 we only check this field
306 * when encryption is occurring (see later check). For the
307 * ServerHello after an HRR we haven't actually selected TLSv1.3
308 * yet, but we still treat it as TLSv1.3, so we must check for
311 if (!s->first_packet && !SSL_IS_TLS13(s)
312 && s->hello_retry_request != SSL_HRR_PENDING
313 && version != (unsigned int)s->version) {
314 if ((s->version & 0xFF00) == (version & 0xFF00)
315 && !s->enc_write_ctx && !s->write_hash) {
316 if (thisrr->type == SSL3_RT_ALERT) {
318 * The record is using an incorrect version number,
319 * but what we've got appears to be an alert. We
320 * haven't read the body yet to check whether its a
321 * fatal or not - but chances are it is. We probably
322 * shouldn't send a fatal alert back. We'll just
325 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
326 SSL_R_WRONG_VERSION_NUMBER);
330 * Send back error using their minor version number :-)
332 s->version = (unsigned short)version;
334 SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL3_GET_RECORD,
335 SSL_R_WRONG_VERSION_NUMBER);
339 if ((version >> 8) != SSL3_VERSION_MAJOR) {
340 if (RECORD_LAYER_is_first_record(&s->rlayer)) {
341 /* Go back to start of packet, look at the five bytes
343 p = RECORD_LAYER_get_packet(&s->rlayer);
344 if (strncmp((char *)p, "GET ", 4) == 0 ||
345 strncmp((char *)p, "POST ", 5) == 0 ||
346 strncmp((char *)p, "HEAD ", 5) == 0 ||
347 strncmp((char *)p, "PUT ", 4) == 0) {
348 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
351 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
352 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
353 SSL_R_HTTPS_PROXY_REQUEST);
357 /* Doesn't look like TLS - don't send an alert */
358 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
359 SSL_R_WRONG_VERSION_NUMBER);
362 SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
363 SSL_F_SSL3_GET_RECORD,
364 SSL_R_WRONG_VERSION_NUMBER);
369 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
370 if (thisrr->type != SSL3_RT_APPLICATION_DATA
371 && (thisrr->type != SSL3_RT_CHANGE_CIPHER_SPEC
372 || !SSL_IS_FIRST_HANDSHAKE(s))
373 && (thisrr->type != SSL3_RT_ALERT
374 || s->statem.enc_read_state
375 != ENC_READ_STATE_ALLOW_PLAIN_ALERTS)) {
376 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
377 SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
380 if (thisrr->rec_version != TLS1_2_VERSION) {
381 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
382 SSL_R_WRONG_VERSION_NUMBER);
388 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
389 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
390 SSL_R_PACKET_LENGTH_TOO_LONG);
395 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
398 if (SSL_IS_TLS13(s)) {
399 if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
400 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
401 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
405 size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
407 #ifndef OPENSSL_NO_COMP
409 * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
410 * does not include the compression overhead anyway.
412 if (s->expand == NULL)
413 len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
416 if (thisrr->length > len && !BIO_get_ktls_recv(s->rbio)) {
417 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
418 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
424 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
425 * Calculate how much more data we need to read for the rest of the
428 if (thisrr->rec_version == SSL2_VERSION) {
429 more = thisrr->length + SSL2_RT_HEADER_LENGTH
430 - SSL3_RT_HEADER_LENGTH;
432 more = thisrr->length;
436 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
438 rret = ssl3_read_n(s, more, more, 1, 0, &n);
440 return rret; /* error or non-blocking io */
443 /* set state for later operations */
444 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
447 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH
448 * + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
449 * + thisrr->length and we have that many bytes in s->packet
451 if (thisrr->rec_version == SSL2_VERSION) {
453 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
456 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
460 * ok, we can now read from 's->packet' data into 'thisrr' thisrr->input
461 * points at thisrr->length bytes, which need to be copied into
462 * thisrr->data by either the decryption or by the decompression When
463 * the data is 'copied' into the thisrr->data buffer, thisrr->input will
464 * be pointed at the new buffer
468 * We now have - encrypted [ MAC [ compressed [ plain ] ] ]
469 * thisrr->length bytes of encrypted compressed stuff.
472 /* decrypt in place in 'thisrr->input' */
473 thisrr->data = thisrr->input;
474 thisrr->orig_len = thisrr->length;
476 /* Mark this record as not read by upper layers yet */
481 /* we have pulled in a full packet so zero things */
482 RECORD_LAYER_reset_packet_length(&s->rlayer);
483 RECORD_LAYER_clear_first_record(&s->rlayer);
484 } while (num_recs < max_recs
485 && thisrr->type == SSL3_RT_APPLICATION_DATA
486 && SSL_USE_EXPLICIT_IV(s)
487 && s->enc_read_ctx != NULL
488 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
489 & EVP_CIPH_FLAG_PIPELINE)
490 && ssl3_record_app_data_waiting(s));
493 && thisrr->type == SSL3_RT_CHANGE_CIPHER_SPEC
494 && (SSL_IS_TLS13(s) || s->hello_retry_request != SSL_HRR_NONE)
495 && SSL_IS_FIRST_HANDSHAKE(s)) {
497 * CCS messages must be exactly 1 byte long, containing the value 0x01
499 if (thisrr->length != 1 || thisrr->data[0] != 0x01) {
500 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SSL3_GET_RECORD,
501 SSL_R_INVALID_CCS_MESSAGE);
505 * CCS messages are ignored in TLSv1.3. We treat it like an empty
508 thisrr->type = SSL3_RT_HANDSHAKE;
509 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
510 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
511 > MAX_EMPTY_RECORDS) {
512 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
513 SSL_R_UNEXPECTED_CCS_MESSAGE);
517 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
523 * KTLS reads full records. If there is any data left,
524 * then it is from before enabling ktls
526 if (BIO_get_ktls_recv(s->rbio) && !is_ktls_left)
527 goto skip_decryption;
530 * If in encrypt-then-mac mode calculate mac from encrypted record. All
531 * the details below are public so no timing details can leak.
533 if (SSL_READ_ETM(s) && s->read_hash) {
535 /* TODO(size_t): convert this to do size_t properly */
536 imac_size = EVP_MD_CTX_size(s->read_hash);
537 if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
538 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
542 mac_size = (size_t)imac_size;
543 for (j = 0; j < num_recs; j++) {
546 if (thisrr->length < mac_size) {
547 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
548 SSL_R_LENGTH_TOO_SHORT);
551 thisrr->length -= mac_size;
552 mac = thisrr->data + thisrr->length;
553 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
554 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
555 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
556 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
562 first_rec_len = rr[0].length;
564 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
568 * 0: (in non-constant time) if the record is publicly invalid.
569 * 1: if the padding is valid
570 * -1: if the padding is invalid
573 if (ossl_statem_in_error(s)) {
574 /* SSLfatal() already got called */
577 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
579 * Valid early_data that we cannot decrypt might fail here as
580 * publicly invalid. We treat it like an empty record.
585 if (!early_data_count_ok(s, thisrr->length,
586 EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
587 /* SSLfatal() already called */
593 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
594 RECORD_LAYER_reset_read_sequence(&s->rlayer);
597 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
598 SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
601 OSSL_TRACE_BEGIN(TLS) {
602 BIO_printf(trc_out, "dec %lu\n", (unsigned long)rr[0].length);
603 BIO_dump_indent(trc_out, rr[0].data, rr[0].length, 4);
604 } OSSL_TRACE_END(TLS);
606 /* r->length is now the compressed data plus mac */
607 if ((sess != NULL) &&
608 (s->enc_read_ctx != NULL) &&
609 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
610 /* s->read_hash != NULL => mac_size != -1 */
611 unsigned char *mac = NULL;
612 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
614 mac_size = EVP_MD_CTX_size(s->read_hash);
615 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
616 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
617 ERR_R_INTERNAL_ERROR);
621 for (j = 0; j < num_recs; j++) {
624 * orig_len is the length of the record before any padding was
625 * removed. This is public information, as is the MAC in use,
626 * therefore we can safely process the record in a different amount
627 * of time if it's too short to possibly contain a MAC.
629 if (thisrr->orig_len < mac_size ||
630 /* CBC records must have a padding length byte too. */
631 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
632 thisrr->orig_len < mac_size + 1)) {
633 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
634 SSL_R_LENGTH_TOO_SHORT);
638 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
640 * We update the length so that the TLS header bytes can be
641 * constructed correctly but we need to extract the MAC in
642 * constant time from within the record, without leaking the
643 * contents of the padding bytes.
646 if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
647 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
648 ERR_R_INTERNAL_ERROR);
651 thisrr->length -= mac_size;
654 * In this case there's no padding, so |rec->orig_len| equals
655 * |rec->length| and we checked that there's enough bytes for
658 thisrr->length -= mac_size;
659 mac = &thisrr->data[thisrr->length];
662 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
663 if (i == 0 || mac == NULL
664 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
666 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
672 if (ossl_statem_in_error(s)) {
673 /* We already called SSLfatal() */
676 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
678 * We assume this is unreadable early_data - we treat it like an
683 * The record length may have been modified by the mac check above
684 * so we use the previously saved value
686 if (!early_data_count_ok(s, first_rec_len,
687 EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
688 /* SSLfatal() already called */
695 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
696 RECORD_LAYER_reset_read_sequence(&s->rlayer);
700 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
701 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
702 * failure is directly visible from the ciphertext anyway, we should
703 * not reveal which kind of error occurred -- this might become
704 * visible to an attacker (e.g. via a logfile)
706 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
707 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
713 for (j = 0; j < num_recs; j++) {
716 /* thisrr->length is now just compressed */
717 if (s->expand != NULL) {
718 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
719 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
720 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
723 if (!ssl3_do_uncompress(s, thisrr)) {
724 SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_F_SSL3_GET_RECORD,
725 SSL_R_BAD_DECOMPRESSION);
731 && s->enc_read_ctx != NULL
732 && thisrr->type != SSL3_RT_ALERT) {
735 if (thisrr->length == 0
736 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
737 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
738 SSL_R_BAD_RECORD_TYPE);
742 /* Strip trailing padding */
743 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
747 thisrr->length = end;
748 thisrr->type = thisrr->data[end];
749 if (thisrr->type != SSL3_RT_APPLICATION_DATA
750 && thisrr->type != SSL3_RT_ALERT
751 && thisrr->type != SSL3_RT_HANDSHAKE) {
752 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
753 SSL_R_BAD_RECORD_TYPE);
757 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
758 &thisrr->data[end], 1, s, s->msg_callback_arg);
762 * TLSv1.3 alert and handshake records are required to be non-zero in
766 && (thisrr->type == SSL3_RT_HANDSHAKE
767 || thisrr->type == SSL3_RT_ALERT)
768 && thisrr->length == 0) {
769 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
774 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH && !BIO_get_ktls_recv(s->rbio)) {
775 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
776 SSL_R_DATA_LENGTH_TOO_LONG);
780 /* If received packet overflows current Max Fragment Length setting */
781 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
782 && thisrr->length > GET_MAX_FRAGMENT_LENGTH(s->session)
783 && !BIO_get_ktls_recv(s->rbio)) {
784 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
785 SSL_R_DATA_LENGTH_TOO_LONG);
791 * So at this point the following is true
792 * thisrr->type is the type of record
793 * thisrr->length == number of bytes in record
794 * thisrr->off == offset to first valid byte
795 * thisrr->data == where to take bytes from, increment after use :-).
798 /* just read a 0 length packet */
799 if (thisrr->length == 0) {
800 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
801 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
802 > MAX_EMPTY_RECORDS) {
803 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
804 SSL_R_RECORD_TOO_SMALL);
808 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
812 if (s->early_data_state == SSL_EARLY_DATA_READING) {
814 if (thisrr->type == SSL3_RT_APPLICATION_DATA
815 && !early_data_count_ok(s, thisrr->length, 0, 0)) {
816 /* SSLfatal already called */
821 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
825 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
827 #ifndef OPENSSL_NO_COMP
830 if (rr->comp == NULL) {
831 rr->comp = (unsigned char *)
832 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
834 if (rr->comp == NULL)
837 /* TODO(size_t): Convert this call */
838 i = COMP_expand_block(ssl->expand, rr->comp,
839 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
849 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
851 #ifndef OPENSSL_NO_COMP
854 /* TODO(size_t): Convert this call */
855 i = COMP_compress_block(ssl->compress, wr->data,
856 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
857 wr->input, (int)wr->length);
863 wr->input = wr->data;
869 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|. Will call
870 * SSLfatal() for internal errors, but not otherwise.
873 * 0: (in non-constant time) if the record is publicly invalid (i.e. too
875 * 1: if the record's padding is valid / the encryption was successful.
876 * -1: if the record's padding is invalid or, if sending, an internal error
879 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
884 size_t bs, mac_size = 0;
886 const EVP_CIPHER *enc;
890 * We shouldn't ever be called with more than one record in the SSLv3 case
895 ds = s->enc_write_ctx;
896 if (s->enc_write_ctx == NULL)
899 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
901 ds = s->enc_read_ctx;
902 if (s->enc_read_ctx == NULL)
905 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
908 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
909 memmove(rec->data, rec->input, rec->length);
910 rec->input = rec->data;
913 /* TODO(size_t): Convert this call */
914 bs = EVP_CIPHER_CTX_block_size(ds);
918 if ((bs != 1) && sending) {
921 /* we need to add 'i-1' padding bytes */
924 * the last of these zero bytes will be overwritten with the
927 memset(&rec->input[rec->length], 0, i);
929 rec->input[l - 1] = (unsigned char)(i - 1);
933 if (l == 0 || l % bs != 0)
935 /* otherwise, rec->length >= bs */
938 /* TODO(size_t): Convert this call */
939 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
942 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
943 /* TODO(size_t): convert me */
944 imac_size = EVP_MD_CTX_size(s->read_hash);
946 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_ENC,
947 ERR_R_INTERNAL_ERROR);
950 mac_size = (size_t)imac_size;
952 if ((bs != 1) && !sending)
953 return ssl3_cbc_remove_padding(rec, bs, mac_size);
958 #define MAX_PADDING 256
960 * tls1_enc encrypts/decrypts |n_recs| in |recs|. Will call SSLfatal() for
961 * internal errors, but not otherwise.
964 * 0: (in non-constant time) if the record is publicly invalid (i.e. too
966 * 1: if the record's padding is valid / the encryption was successful.
967 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
968 * an internal error occurred.
970 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
973 size_t reclen[SSL_MAX_PIPELINES];
974 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
975 int i, pad = 0, ret, tmpr;
976 size_t bs, mac_size = 0, ctr, padnum, loop;
977 unsigned char padval;
979 const EVP_CIPHER *enc;
982 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
983 ERR_R_INTERNAL_ERROR);
988 if (EVP_MD_CTX_md(s->write_hash)) {
989 int n = EVP_MD_CTX_size(s->write_hash);
990 if (!ossl_assert(n >= 0)) {
991 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
992 ERR_R_INTERNAL_ERROR);
996 ds = s->enc_write_ctx;
997 if (s->enc_write_ctx == NULL)
1001 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
1002 /* For TLSv1.1 and later explicit IV */
1003 if (SSL_USE_EXPLICIT_IV(s)
1004 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
1005 ivlen = EVP_CIPHER_iv_length(enc);
1009 for (ctr = 0; ctr < n_recs; ctr++) {
1010 if (recs[ctr].data != recs[ctr].input) {
1012 * we can't write into the input stream: Can this ever
1015 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1016 ERR_R_INTERNAL_ERROR);
1018 } else if (RAND_bytes_ex(s->ctx->libctx, recs[ctr].input,
1020 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1021 ERR_R_INTERNAL_ERROR);
1028 if (EVP_MD_CTX_md(s->read_hash)) {
1029 int n = EVP_MD_CTX_size(s->read_hash);
1030 if (!ossl_assert(n >= 0)) {
1031 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1032 ERR_R_INTERNAL_ERROR);
1036 ds = s->enc_read_ctx;
1037 if (s->enc_read_ctx == NULL)
1040 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
1043 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
1044 for (ctr = 0; ctr < n_recs; ctr++) {
1045 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
1046 recs[ctr].input = recs[ctr].data;
1050 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
1053 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1054 & EVP_CIPH_FLAG_PIPELINE)) {
1056 * We shouldn't have been called with pipeline data if the
1057 * cipher doesn't support pipelining
1059 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1060 SSL_R_PIPELINE_FAILURE);
1064 for (ctr = 0; ctr < n_recs; ctr++) {
1065 reclen[ctr] = recs[ctr].length;
1067 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1068 & EVP_CIPH_FLAG_AEAD_CIPHER) {
1071 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
1072 : RECORD_LAYER_get_read_sequence(&s->rlayer);
1074 if (SSL_IS_DTLS(s)) {
1075 /* DTLS does not support pipelining */
1076 unsigned char dtlsseq[9], *p = dtlsseq;
1078 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
1079 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
1080 memcpy(p, &seq[2], 6);
1081 memcpy(buf[ctr], dtlsseq, 8);
1083 memcpy(buf[ctr], seq, 8);
1084 for (i = 7; i >= 0; i--) { /* increment */
1091 buf[ctr][8] = recs[ctr].type;
1092 buf[ctr][9] = (unsigned char)(s->version >> 8);
1093 buf[ctr][10] = (unsigned char)(s->version);
1094 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
1095 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
1096 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
1097 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
1099 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1100 ERR_R_INTERNAL_ERROR);
1106 recs[ctr].length += pad;
1109 } else if ((bs != 1) && sending) {
1110 padnum = bs - (reclen[ctr] % bs);
1112 /* Add weird padding of up to 256 bytes */
1114 if (padnum > MAX_PADDING) {
1115 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1116 ERR_R_INTERNAL_ERROR);
1119 /* we need to add 'padnum' padding bytes of value padval */
1120 padval = (unsigned char)(padnum - 1);
1121 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
1122 recs[ctr].input[loop] = padval;
1123 reclen[ctr] += padnum;
1124 recs[ctr].length += padnum;
1128 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
1133 unsigned char *data[SSL_MAX_PIPELINES];
1135 /* Set the output buffers */
1136 for (ctr = 0; ctr < n_recs; ctr++) {
1137 data[ctr] = recs[ctr].data;
1139 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
1140 (int)n_recs, data) <= 0) {
1141 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1142 SSL_R_PIPELINE_FAILURE);
1145 /* Set the input buffers */
1146 for (ctr = 0; ctr < n_recs; ctr++) {
1147 data[ctr] = recs[ctr].input;
1149 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
1150 (int)n_recs, data) <= 0
1151 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1152 (int)n_recs, reclen) <= 0) {
1153 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1154 SSL_R_PIPELINE_FAILURE);
1159 /* TODO(size_t): Convert this call */
1160 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1161 (unsigned int)reclen[0]);
1162 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1163 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1166 return -1; /* AEAD can fail to verify MAC */
1169 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1170 for (ctr = 0; ctr < n_recs; ctr++) {
1171 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1172 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1173 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1175 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1176 for (ctr = 0; ctr < n_recs; ctr++) {
1177 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1178 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1179 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1185 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1186 imac_size = EVP_MD_CTX_size(s->read_hash);
1187 if (imac_size < 0) {
1188 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1189 ERR_R_INTERNAL_ERROR);
1192 mac_size = (size_t)imac_size;
1194 if ((bs != 1) && !sending) {
1196 for (ctr = 0; ctr < n_recs; ctr++) {
1197 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1199 * If tmpret == 0 then this means publicly invalid so we can
1200 * short circuit things here. Otherwise we must respect constant
1205 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1209 if (pad && !sending) {
1210 for (ctr = 0; ctr < n_recs; ctr++) {
1211 recs[ctr].length -= pad;
1218 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1220 unsigned char *mac_sec, *seq;
1221 const EVP_MD_CTX *hash;
1222 unsigned char *p, rec_char;
1228 mac_sec = &(ssl->s3.write_mac_secret[0]);
1229 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1230 hash = ssl->write_hash;
1232 mac_sec = &(ssl->s3.read_mac_secret[0]);
1233 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1234 hash = ssl->read_hash;
1237 t = EVP_MD_CTX_size(hash);
1241 npad = (48 / md_size) * md_size;
1244 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1245 ssl3_cbc_record_digest_supported(hash)) {
1247 * This is a CBC-encrypted record. We must avoid leaking any
1248 * timing-side channel information about how many blocks of data we
1249 * are hashing because that gives an attacker a timing-oracle.
1253 * npad is, at most, 48 bytes and that's with MD5:
1254 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1256 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1257 * goes up 4, but npad goes down by 8, resulting in a smaller
1260 unsigned char header[75];
1262 memcpy(header + j, mac_sec, md_size);
1264 memcpy(header + j, ssl3_pad_1, npad);
1266 memcpy(header + j, seq, 8);
1268 header[j++] = rec->type;
1269 header[j++] = (unsigned char)(rec->length >> 8);
1270 header[j++] = (unsigned char)(rec->length & 0xff);
1272 /* Final param == is SSLv3 */
1273 if (ssl3_cbc_digest_record(ssl, hash,
1276 rec->length + md_size, rec->orig_len,
1277 mac_sec, md_size, 1) <= 0)
1280 unsigned int md_size_u;
1281 /* Chop the digest off the end :-) */
1282 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1287 rec_char = rec->type;
1289 s2n(rec->length, p);
1290 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1291 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1292 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1293 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1294 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1295 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1296 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1297 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1298 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1299 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1300 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1301 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1302 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1303 EVP_MD_CTX_free(md_ctx);
1307 EVP_MD_CTX_free(md_ctx);
1310 ssl3_record_sequence_update(seq);
1314 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1320 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1321 unsigned char header[13];
1322 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1323 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1327 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1328 hash = ssl->write_hash;
1330 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1331 hash = ssl->read_hash;
1334 t = EVP_MD_CTX_size(hash);
1335 if (!ossl_assert(t >= 0))
1339 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1343 hmac = EVP_MD_CTX_new();
1344 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash)) {
1345 EVP_MD_CTX_free(hmac);
1351 if (SSL_IS_DTLS(ssl)) {
1352 unsigned char dtlsseq[8], *p = dtlsseq;
1354 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1355 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1356 memcpy(p, &seq[2], 6);
1358 memcpy(header, dtlsseq, 8);
1360 memcpy(header, seq, 8);
1362 header[8] = rec->type;
1363 header[9] = (unsigned char)(ssl->version >> 8);
1364 header[10] = (unsigned char)(ssl->version);
1365 header[11] = (unsigned char)(rec->length >> 8);
1366 header[12] = (unsigned char)(rec->length & 0xff);
1368 if (!sending && !SSL_READ_ETM(ssl) &&
1369 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1370 ssl3_cbc_record_digest_supported(mac_ctx)) {
1372 * This is a CBC-encrypted record. We must avoid leaking any
1373 * timing-side channel information about how many blocks of data we
1374 * are hashing because that gives an attacker a timing-oracle.
1376 /* Final param == not SSLv3 */
1377 if (ssl3_cbc_digest_record(ssl, mac_ctx,
1380 rec->length + md_size, rec->orig_len,
1381 ssl->s3.read_mac_secret,
1382 ssl->s3.read_mac_secret_size, 0) <= 0) {
1383 EVP_MD_CTX_free(hmac);
1387 /* TODO(size_t): Convert these calls */
1388 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1389 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1390 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1391 EVP_MD_CTX_free(hmac);
1396 EVP_MD_CTX_free(hmac);
1398 OSSL_TRACE_BEGIN(TLS) {
1399 BIO_printf(trc_out, "seq:\n");
1400 BIO_dump_indent(trc_out, seq, 8, 4);
1401 BIO_printf(trc_out, "rec:\n");
1402 BIO_dump_indent(trc_out, rec->data, rec->length, 4);
1403 } OSSL_TRACE_END(TLS);
1405 if (!SSL_IS_DTLS(ssl)) {
1406 for (i = 7; i >= 0; i--) {
1412 OSSL_TRACE_BEGIN(TLS) {
1413 BIO_printf(trc_out, "md:\n");
1414 BIO_dump_indent(trc_out, md, md_size, 4);
1415 } OSSL_TRACE_END(TLS);
1420 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1421 * record in |rec| by updating |rec->length| in constant time.
1423 * block_size: the block size of the cipher used to encrypt the record.
1425 * 0: (in non-constant time) if the record is publicly invalid.
1426 * 1: if the padding was valid
1429 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1430 size_t block_size, size_t mac_size)
1432 size_t padding_length;
1434 const size_t overhead = 1 /* padding length byte */ + mac_size;
1437 * These lengths are all public so we can test them in non-constant time.
1439 if (overhead > rec->length)
1442 padding_length = rec->data[rec->length - 1];
1443 good = constant_time_ge_s(rec->length, padding_length + overhead);
1444 /* SSLv3 requires that the padding is minimal. */
1445 good &= constant_time_ge_s(block_size, padding_length + 1);
1446 rec->length -= good & (padding_length + 1);
1447 return constant_time_select_int_s(good, 1, -1);
1451 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1452 * record in |rec| in constant time and returns 1 if the padding is valid and
1453 * -1 otherwise. It also removes any explicit IV from the start of the record
1454 * without leaking any timing about whether there was enough space after the
1455 * padding was removed.
1457 * block_size: the block size of the cipher used to encrypt the record.
1459 * 0: (in non-constant time) if the record is publicly invalid.
1460 * 1: if the padding was valid
1463 int tls1_cbc_remove_padding(const SSL *s,
1465 size_t block_size, size_t mac_size)
1468 size_t padding_length, to_check, i;
1469 const size_t overhead = 1 /* padding length byte */ + mac_size;
1470 /* Check if version requires explicit IV */
1471 if (SSL_USE_EXPLICIT_IV(s)) {
1473 * These lengths are all public so we can test them in non-constant
1476 if (overhead + block_size > rec->length)
1478 /* We can now safely skip explicit IV */
1479 rec->data += block_size;
1480 rec->input += block_size;
1481 rec->length -= block_size;
1482 rec->orig_len -= block_size;
1483 } else if (overhead > rec->length)
1486 padding_length = rec->data[rec->length - 1];
1488 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1489 EVP_CIPH_FLAG_AEAD_CIPHER) {
1490 /* padding is already verified */
1491 rec->length -= padding_length + 1;
1495 good = constant_time_ge_s(rec->length, overhead + padding_length);
1497 * The padding consists of a length byte at the end of the record and
1498 * then that many bytes of padding, all with the same value as the length
1499 * byte. Thus, with the length byte included, there are i+1 bytes of
1500 * padding. We can't check just |padding_length+1| bytes because that
1501 * leaks decrypted information. Therefore we always have to check the
1502 * maximum amount of padding possible. (Again, the length of the record
1503 * is public information so we can use it.)
1505 to_check = 256; /* maximum amount of padding, inc length byte. */
1506 if (to_check > rec->length)
1507 to_check = rec->length;
1509 for (i = 0; i < to_check; i++) {
1510 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1511 unsigned char b = rec->data[rec->length - 1 - i];
1513 * The final |padding_length+1| bytes should all have the value
1514 * |padding_length|. Therefore the XOR should be zero.
1516 good &= ~(mask & (padding_length ^ b));
1520 * If any of the final |padding_length+1| bytes had the wrong value, one
1521 * or more of the lower eight bits of |good| will be cleared.
1523 good = constant_time_eq_s(0xff, good & 0xff);
1524 rec->length -= good & (padding_length + 1);
1526 return constant_time_select_int_s(good, 1, -1);
1530 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1531 * constant time (independent of the concrete value of rec->length, which may
1532 * vary within a 256-byte window).
1534 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1538 * rec->orig_len >= md_size
1539 * md_size <= EVP_MAX_MD_SIZE
1541 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1542 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1543 * a single or pair of cache-lines, then the variable memory accesses don't
1544 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1545 * not multi-core and are not considered vulnerable to cache-timing attacks.
1547 #define CBC_MAC_ROTATE_IN_PLACE
1549 int ssl3_cbc_copy_mac(unsigned char *out,
1550 const SSL3_RECORD *rec, size_t md_size)
1552 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1553 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1554 unsigned char *rotated_mac;
1556 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1560 * mac_end is the index of |rec->data| just after the end of the MAC.
1562 size_t mac_end = rec->length;
1563 size_t mac_start = mac_end - md_size;
1566 * scan_start contains the number of bytes that we can ignore because the
1567 * MAC's position can only vary by 255 bytes.
1569 size_t scan_start = 0;
1571 size_t rotate_offset;
1573 if (!ossl_assert(rec->orig_len >= md_size
1574 && md_size <= EVP_MAX_MD_SIZE))
1577 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1578 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1581 /* This information is public so it's safe to branch based on it. */
1582 if (rec->orig_len > md_size + 255 + 1)
1583 scan_start = rec->orig_len - (md_size + 255 + 1);
1587 memset(rotated_mac, 0, md_size);
1588 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1589 size_t mac_started = constant_time_eq_s(i, mac_start);
1590 size_t mac_ended = constant_time_lt_s(i, mac_end);
1591 unsigned char b = rec->data[i];
1593 in_mac |= mac_started;
1594 in_mac &= mac_ended;
1595 rotate_offset |= j & mac_started;
1596 rotated_mac[j++] |= b & in_mac;
1597 j &= constant_time_lt_s(j, md_size);
1600 /* Now rotate the MAC */
1601 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1603 for (i = 0; i < md_size; i++) {
1604 /* in case cache-line is 32 bytes, touch second line */
1605 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1606 out[j++] = rotated_mac[rotate_offset++];
1607 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1610 memset(out, 0, md_size);
1611 rotate_offset = md_size - rotate_offset;
1612 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1613 for (i = 0; i < md_size; i++) {
1614 for (j = 0; j < md_size; j++)
1615 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1617 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1624 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1632 unsigned char md[EVP_MAX_MD_SIZE];
1633 size_t max_plain_length = SSL3_RT_MAX_PLAIN_LENGTH;
1635 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1639 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1640 * and we have that many bytes in s->packet
1642 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1645 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1646 * at rr->length bytes, which need to be copied into rr->data by either
1647 * the decryption or by the decompression When the data is 'copied' into
1648 * the rr->data buffer, rr->input will be pointed at the new buffer
1652 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1653 * bytes of encrypted compressed stuff.
1656 /* check is not needed I believe */
1657 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1658 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
1659 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1663 /* decrypt in place in 'rr->input' */
1664 rr->data = rr->input;
1665 rr->orig_len = rr->length;
1667 if (SSL_READ_ETM(s) && s->read_hash) {
1669 mac_size = EVP_MD_CTX_size(s->read_hash);
1670 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1671 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1672 ERR_R_INTERNAL_ERROR);
1675 if (rr->orig_len < mac_size) {
1676 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1677 SSL_R_LENGTH_TOO_SHORT);
1680 rr->length -= mac_size;
1681 mac = rr->data + rr->length;
1682 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1683 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1684 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_DTLS1_PROCESS_RECORD,
1685 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1690 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1693 * 0: (in non-constant time) if the record is publicly invalid.
1694 * 1: if the padding is valid
1695 * -1: if the padding is invalid
1698 if (ossl_statem_in_error(s)) {
1699 /* SSLfatal() got called */
1702 /* For DTLS we simply ignore bad packets. */
1704 RECORD_LAYER_reset_packet_length(&s->rlayer);
1707 OSSL_TRACE_BEGIN(TLS) {
1708 BIO_printf(trc_out, "dec %zd\n", rr->length);
1709 BIO_dump_indent(trc_out, rr->data, rr->length, 4);
1710 } OSSL_TRACE_END(TLS);
1712 /* r->length is now the compressed data plus mac */
1713 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1714 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1715 /* s->read_hash != NULL => mac_size != -1 */
1716 unsigned char *mac = NULL;
1717 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1719 /* TODO(size_t): Convert this to do size_t properly */
1720 imac_size = EVP_MD_CTX_size(s->read_hash);
1721 if (imac_size < 0) {
1722 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1726 mac_size = (size_t)imac_size;
1727 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1728 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1729 ERR_R_INTERNAL_ERROR);
1734 * orig_len is the length of the record before any padding was
1735 * removed. This is public information, as is the MAC in use,
1736 * therefore we can safely process the record in a different amount
1737 * of time if it's too short to possibly contain a MAC.
1739 if (rr->orig_len < mac_size ||
1740 /* CBC records must have a padding length byte too. */
1741 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1742 rr->orig_len < mac_size + 1)) {
1743 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1744 SSL_R_LENGTH_TOO_SHORT);
1748 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1750 * We update the length so that the TLS header bytes can be
1751 * constructed correctly but we need to extract the MAC in
1752 * constant time from within the record, without leaking the
1753 * contents of the padding bytes.
1756 if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
1757 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1758 ERR_R_INTERNAL_ERROR);
1761 rr->length -= mac_size;
1764 * In this case there's no padding, so |rec->orig_len| equals
1765 * |rec->length| and we checked that there's enough bytes for
1768 rr->length -= mac_size;
1769 mac = &rr->data[rr->length];
1772 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1773 if (i == 0 || mac == NULL
1774 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1776 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1781 /* decryption failed, silently discard message */
1783 RECORD_LAYER_reset_packet_length(&s->rlayer);
1787 /* r->length is now just compressed */
1788 if (s->expand != NULL) {
1789 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1790 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
1791 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1794 if (!ssl3_do_uncompress(s, rr)) {
1795 SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE,
1796 SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1801 /* use current Max Fragment Length setting if applicable */
1802 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session))
1803 max_plain_length = GET_MAX_FRAGMENT_LENGTH(s->session);
1805 /* send overflow if the plaintext is too long now it has passed MAC */
1806 if (rr->length > max_plain_length) {
1807 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
1808 SSL_R_DATA_LENGTH_TOO_LONG);
1814 * So at this point the following is true
1815 * ssl->s3.rrec.type is the type of record
1816 * ssl->s3.rrec.length == number of bytes in record
1817 * ssl->s3.rrec.off == offset to first valid byte
1818 * ssl->s3.rrec.data == where to take bytes from, increment
1822 /* we have pulled in a full packet so zero things */
1823 RECORD_LAYER_reset_packet_length(&s->rlayer);
1825 /* Mark receipt of record. */
1826 dtls1_record_bitmap_update(s, bitmap);
1832 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1834 #define dtls1_get_processed_record(s) \
1835 dtls1_retrieve_buffered_record((s), \
1836 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1839 * Call this to get a new input record.
1840 * It will return <= 0 if more data is needed, normally due to an error
1841 * or non-blocking IO.
1842 * When it finishes, one packet has been decoded and can be found in
1843 * ssl->s3.rrec.type - is the type of record
1844 * ssl->s3.rrec.data - data
1845 * ssl->s3.rrec.length - number of bytes
1847 /* used only by dtls1_read_bytes */
1848 int dtls1_get_record(SSL *s)
1850 int ssl_major, ssl_minor;
1854 unsigned char *p = NULL;
1855 unsigned short version;
1856 DTLS1_BITMAP *bitmap;
1857 unsigned int is_next_epoch;
1859 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1863 * The epoch may have changed. If so, process all the pending records.
1864 * This is a non-blocking operation.
1866 if (!dtls1_process_buffered_records(s)) {
1867 /* SSLfatal() already called */
1871 /* if we're renegotiating, then there may be buffered records */
1872 if (dtls1_get_processed_record(s))
1875 /* get something from the wire */
1877 /* check if we have the header */
1878 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1879 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1880 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1881 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1882 /* read timeout is handled by dtls1_read_bytes */
1884 /* SSLfatal() already called if appropriate */
1885 return rret; /* error or non-blocking */
1888 /* this packet contained a partial record, dump it */
1889 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1890 DTLS1_RT_HEADER_LENGTH) {
1891 RECORD_LAYER_reset_packet_length(&s->rlayer);
1895 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1897 p = RECORD_LAYER_get_packet(&s->rlayer);
1899 if (s->msg_callback)
1900 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1901 s, s->msg_callback_arg);
1903 /* Pull apart the header into the DTLS1_RECORD */
1907 version = (ssl_major << 8) | ssl_minor;
1909 /* sequence number is 64 bits, with top 2 bytes = epoch */
1912 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1919 * Lets check the version. We tolerate alerts that don't have the exact
1920 * version number (e.g. because of protocol version errors)
1922 if (!s->first_packet && rr->type != SSL3_RT_ALERT) {
1923 if (version != s->version) {
1924 /* unexpected version, silently discard */
1927 RECORD_LAYER_reset_packet_length(&s->rlayer);
1932 if ((version & 0xff00) != (s->version & 0xff00)) {
1933 /* wrong version, silently discard record */
1936 RECORD_LAYER_reset_packet_length(&s->rlayer);
1940 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1941 /* record too long, silently discard it */
1944 RECORD_LAYER_reset_packet_length(&s->rlayer);
1948 /* If received packet overflows own-client Max Fragment Length setting */
1949 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
1950 && rr->length > GET_MAX_FRAGMENT_LENGTH(s->session) + SSL3_RT_MAX_ENCRYPTED_OVERHEAD) {
1951 /* record too long, silently discard it */
1954 RECORD_LAYER_reset_packet_length(&s->rlayer);
1958 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1961 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1964 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1965 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1967 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1968 /* this packet contained a partial record, dump it */
1969 if (rret <= 0 || n != more) {
1970 if (ossl_statem_in_error(s)) {
1971 /* ssl3_read_n() called SSLfatal() */
1976 RECORD_LAYER_reset_packet_length(&s->rlayer);
1981 * now n == rr->length, and s->packet_length ==
1982 * DTLS1_RT_HEADER_LENGTH + rr->length
1985 /* set state for later operations */
1986 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1988 /* match epochs. NULL means the packet is dropped on the floor */
1989 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1990 if (bitmap == NULL) {
1992 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1993 goto again; /* get another record */
1995 #ifndef OPENSSL_NO_SCTP
1996 /* Only do replay check if no SCTP bio */
1997 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1999 /* Check whether this is a repeat, or aged record. */
2001 * TODO: Does it make sense to have replay protection in epoch 0 where
2002 * we have no integrity negotiated yet?
2004 if (!dtls1_record_replay_check(s, bitmap)) {
2007 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
2008 goto again; /* get another record */
2010 #ifndef OPENSSL_NO_SCTP
2014 /* just read a 0 length packet */
2015 if (rr->length == 0) {
2021 * If this record is from the next epoch (either HM or ALERT), and a
2022 * handshake is currently in progress, buffer it since it cannot be
2023 * processed at this time.
2025 if (is_next_epoch) {
2026 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
2027 if (dtls1_buffer_record (s,
2028 &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
2030 /* SSLfatal() already called */
2036 RECORD_LAYER_reset_packet_length(&s->rlayer);
2040 if (!dtls1_process_record(s, bitmap)) {
2041 if (ossl_statem_in_error(s)) {
2042 /* dtls1_process_record() called SSLfatal */
2047 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
2048 goto again; /* get another record */
2055 int dtls_buffer_listen_record(SSL *s, size_t len, unsigned char *seq, size_t off)
2059 rr = RECORD_LAYER_get_rrec(&s->rlayer);
2060 memset(rr, 0, sizeof(SSL3_RECORD));
2063 rr->type = SSL3_RT_HANDSHAKE;
2064 memcpy(rr->seq_num, seq, sizeof(rr->seq_num));
2067 s->rlayer.packet = RECORD_LAYER_get_rbuf(&s->rlayer)->buf;
2068 s->rlayer.packet_length = DTLS1_RT_HEADER_LENGTH + len;
2069 rr->data = s->rlayer.packet + DTLS1_RT_HEADER_LENGTH;
2071 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
2072 SSL3_RECORD_get_seq_num(s->rlayer.rrec)) <= 0) {
2073 /* SSLfatal() already called */