2 * Copyright 1995-2017 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 send)
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 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_EARLY_DATA_COUNT_OK,
118 ERR_R_INTERNAL_ERROR);
121 sess = s->psksession;
124 || (s->hit && sess->ext.max_early_data < s->max_early_data))
125 max_early_data = sess->ext.max_early_data;
127 if (max_early_data == 0) {
128 SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
129 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) {
137 SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
138 SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
141 s->early_data_count += length;
147 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
148 * will be processed per call to ssl3_get_record. Without this limit an
149 * attacker could send empty records at a faster rate than we can process and
150 * cause ssl3_get_record to loop forever.
152 #define MAX_EMPTY_RECORDS 32
154 #define SSL2_RT_HEADER_LENGTH 2
156 * Call this to get new input records.
157 * It will return <= 0 if more data is needed, normally due to an error
158 * or non-blocking IO.
159 * When it finishes, |numrpipes| records have been decoded. For each record 'i':
160 * rr[i].type - is the type of record
162 * rr[i].length, - number of bytes
163 * Multiple records will only be returned if the record types are all
164 * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
167 /* used only by ssl3_read_bytes */
168 int ssl3_get_record(SSL *s)
173 SSL3_RECORD *rr, *thisrr;
177 unsigned char md[EVP_MAX_MD_SIZE];
178 unsigned int version;
181 size_t num_recs = 0, max_recs, j;
182 PACKET pkt, sslv2pkt;
183 size_t first_rec_len;
185 rr = RECORD_LAYER_get_rrec(&s->rlayer);
186 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
187 max_recs = s->max_pipelines;
193 thisrr = &rr[num_recs];
195 /* check if we have the header */
196 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
197 (RECORD_LAYER_get_packet_length(&s->rlayer)
198 < SSL3_RT_HEADER_LENGTH)) {
202 rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
203 SSL3_BUFFER_get_len(rbuf), 0,
204 num_recs == 0 ? 1 : 0, &n);
206 return rret; /* error or non-blocking */
207 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
209 p = RECORD_LAYER_get_packet(&s->rlayer);
210 if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
211 RECORD_LAYER_get_packet_length(&s->rlayer))) {
212 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
213 ERR_R_INTERNAL_ERROR);
217 if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
218 || !PACKET_get_1(&sslv2pkt, &type)) {
219 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
220 ERR_R_INTERNAL_ERROR);
224 * The first record received by the server may be a V2ClientHello.
226 if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
227 && (sslv2len & 0x8000) != 0
228 && (type == SSL2_MT_CLIENT_HELLO)) {
232 * |num_recs| here will actually always be 0 because
233 * |num_recs > 0| only ever occurs when we are processing
234 * multiple app data records - which we know isn't the case here
235 * because it is an SSLv2ClientHello. We keep it using
236 * |num_recs| for the sake of consistency
238 thisrr->type = SSL3_RT_HANDSHAKE;
239 thisrr->rec_version = SSL2_VERSION;
241 thisrr->length = sslv2len & 0x7fff;
243 if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
244 - SSL2_RT_HEADER_LENGTH) {
245 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
246 SSL_R_PACKET_LENGTH_TOO_LONG);
250 if (thisrr->length < MIN_SSL2_RECORD_LEN) {
251 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
252 SSL_R_LENGTH_TOO_SHORT);
256 /* SSLv3+ style record */
258 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
259 s->msg_callback_arg);
261 /* Pull apart the header into the SSL3_RECORD */
262 if (!PACKET_get_1(&pkt, &type)
263 || !PACKET_get_net_2(&pkt, &version)
264 || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
265 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
266 ERR_R_INTERNAL_ERROR);
270 thisrr->rec_version = version;
273 * Lets check version. In TLSv1.3 we ignore this field. For the
274 * ServerHello after an HRR we haven't actually selected TLSv1.3
275 * yet, but we still treat it as TLSv1.3, so we must check for
278 if (!s->first_packet && !SSL_IS_TLS13(s)
279 && !s->hello_retry_request
280 && version != (unsigned int)s->version) {
281 if ((s->version & 0xFF00) == (version & 0xFF00)
282 && !s->enc_write_ctx && !s->write_hash) {
283 if (thisrr->type == SSL3_RT_ALERT) {
285 * The record is using an incorrect version number,
286 * but what we've got appears to be an alert. We
287 * haven't read the body yet to check whether its a
288 * fatal or not - but chances are it is. We probably
289 * shouldn't send a fatal alert back. We'll just
292 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
293 SSL_R_WRONG_VERSION_NUMBER);
297 * Send back error using their minor version number :-)
299 s->version = (unsigned short)version;
301 SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL3_GET_RECORD,
302 SSL_R_WRONG_VERSION_NUMBER);
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 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
318 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
319 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
320 SSL_R_HTTPS_PROXY_REQUEST);
324 /* Doesn't look like TLS - don't send an alert */
325 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
326 SSL_R_WRONG_VERSION_NUMBER);
329 SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
330 SSL_F_SSL3_GET_RECORD,
331 SSL_R_WRONG_VERSION_NUMBER);
336 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL
337 && thisrr->type != SSL3_RT_APPLICATION_DATA) {
338 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
339 SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
344 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
345 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
346 SSL_R_PACKET_LENGTH_TOO_LONG);
351 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
354 if (SSL_IS_TLS13(s)) {
355 if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
356 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
357 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
361 size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
363 #ifndef OPENSSL_NO_COMP
365 * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
366 * does not include the compression overhead anyway.
368 if (s->expand == NULL)
369 len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
372 if (thisrr->length > len) {
373 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
374 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
380 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
381 * Calculate how much more data we need to read for the rest of the
384 if (thisrr->rec_version == SSL2_VERSION) {
385 more = thisrr->length + SSL2_RT_HEADER_LENGTH
386 - SSL3_RT_HEADER_LENGTH;
388 more = thisrr->length;
391 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
393 rret = ssl3_read_n(s, more, more, 1, 0, &n);
395 return rret; /* error or non-blocking io */
398 /* set state for later operations */
399 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
402 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH
403 * + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
404 * + thisrr->length and we have that many bytes in s->packet
406 if (thisrr->rec_version == SSL2_VERSION) {
408 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
411 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
415 * ok, we can now read from 's->packet' data into 'thisrr' thisrr->input
416 * points at thisrr->length bytes, which need to be copied into
417 * thisrr->data by either the decryption or by the decompression When
418 * the data is 'copied' into the thisrr->data buffer, thisrr->input will
419 * be pointed at the new buffer
423 * We now have - encrypted [ MAC [ compressed [ plain ] ] ]
424 * thisrr->length bytes of encrypted compressed stuff.
427 /* decrypt in place in 'thisrr->input' */
428 thisrr->data = thisrr->input;
429 thisrr->orig_len = thisrr->length;
431 /* Mark this record as not read by upper layers yet */
436 /* we have pulled in a full packet so zero things */
437 RECORD_LAYER_reset_packet_length(&s->rlayer);
438 RECORD_LAYER_clear_first_record(&s->rlayer);
439 } while (num_recs < max_recs
440 && thisrr->type == SSL3_RT_APPLICATION_DATA
441 && SSL_USE_EXPLICIT_IV(s)
442 && s->enc_read_ctx != NULL
443 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
444 & EVP_CIPH_FLAG_PIPELINE)
445 && ssl3_record_app_data_waiting(s));
448 * If in encrypt-then-mac mode calculate mac from encrypted record. All
449 * the details below are public so no timing details can leak.
451 if (SSL_READ_ETM(s) && s->read_hash) {
453 /* TODO(size_t): convert this to do size_t properly */
454 imac_size = EVP_MD_CTX_size(s->read_hash);
455 if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
456 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
460 mac_size = (size_t)imac_size;
461 for (j = 0; j < num_recs; j++) {
464 if (thisrr->length < mac_size) {
465 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
466 SSL_R_LENGTH_TOO_SHORT);
469 thisrr->length -= mac_size;
470 mac = thisrr->data + thisrr->length;
471 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
472 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
473 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, 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, 0)) {
501 /* SSLfatal() already called */
507 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
508 RECORD_LAYER_reset_read_sequence(&s->rlayer);
511 SSLfatal(s, SSL_AD_DECRYPTION_FAILED, SSL_F_SSL3_GET_RECORD,
512 SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
516 printf("dec %"OSSLzu"\n", rr[0].length);
519 for (z = 0; z < rr[0].length; z++)
520 printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
525 /* r->length is now the compressed data plus mac */
526 if ((sess != NULL) &&
527 (s->enc_read_ctx != NULL) &&
528 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
529 /* s->read_hash != NULL => mac_size != -1 */
530 unsigned char *mac = NULL;
531 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
533 mac_size = EVP_MD_CTX_size(s->read_hash);
534 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
535 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
536 ERR_R_INTERNAL_ERROR);
540 for (j = 0; j < num_recs; j++) {
543 * orig_len is the length of the record before any padding was
544 * removed. This is public information, as is the MAC in use,
545 * therefore we can safely process the record in a different amount
546 * of time if it's too short to possibly contain a MAC.
548 if (thisrr->orig_len < mac_size ||
549 /* CBC records must have a padding length byte too. */
550 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
551 thisrr->orig_len < mac_size + 1)) {
552 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
553 SSL_R_LENGTH_TOO_SHORT);
557 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
559 * We update the length so that the TLS header bytes can be
560 * constructed correctly but we need to extract the MAC in
561 * constant time from within the record, without leaking the
562 * contents of the padding bytes.
565 if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
566 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
567 ERR_R_INTERNAL_ERROR);
570 thisrr->length -= mac_size;
573 * In this case there's no padding, so |rec->orig_len| equals
574 * |rec->length| and we checked that there's enough bytes for
577 thisrr->length -= mac_size;
578 mac = &thisrr->data[thisrr->length];
581 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
582 if (i == 0 || mac == NULL
583 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
585 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
591 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
593 * We assume this is unreadable early_data - we treat it like an
598 * The record length may have been modified by the mac check above
599 * so we use the previously saved value
601 if (!early_data_count_ok(s, first_rec_len,
602 EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
603 /* SSLfatal() already called */
610 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
611 RECORD_LAYER_reset_read_sequence(&s->rlayer);
615 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
616 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
617 * failure is directly visible from the ciphertext anyway, we should
618 * not reveal which kind of error occurred -- this might become
619 * visible to an attacker (e.g. via a logfile)
621 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
622 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
626 for (j = 0; j < num_recs; j++) {
629 /* thisrr->length is now just compressed */
630 if (s->expand != NULL) {
631 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
632 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
633 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
636 if (!ssl3_do_uncompress(s, thisrr)) {
637 SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_F_SSL3_GET_RECORD,
638 SSL_R_BAD_DECOMPRESSION);
643 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
646 if (thisrr->length == 0
647 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
648 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
649 SSL_R_BAD_RECORD_TYPE);
653 /* Strip trailing padding */
654 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
658 thisrr->length = end;
659 thisrr->type = thisrr->data[end];
660 if (thisrr->type != SSL3_RT_APPLICATION_DATA
661 && thisrr->type != SSL3_RT_ALERT
662 && thisrr->type != SSL3_RT_HANDSHAKE) {
663 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
664 SSL_R_BAD_RECORD_TYPE);
668 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
669 &thisrr->data[end], 1, s, s->msg_callback_arg);
673 * TLSv1.3 alert and handshake records are required to be non-zero in
677 && (thisrr->type == SSL3_RT_HANDSHAKE
678 || thisrr->type == SSL3_RT_ALERT)
679 && thisrr->length == 0) {
680 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
685 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
686 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
687 SSL_R_DATA_LENGTH_TOO_LONG);
691 /* If received packet overflows current Max Fragment Length setting */
692 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
693 && thisrr->length > GET_MAX_FRAGMENT_LENGTH(s->session)) {
694 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
695 SSL_R_DATA_LENGTH_TOO_LONG);
701 * So at this point the following is true
702 * thisrr->type is the type of record
703 * thisrr->length == number of bytes in record
704 * thisrr->off == offset to first valid byte
705 * thisrr->data == where to take bytes from, increment after use :-).
708 /* just read a 0 length packet */
709 if (thisrr->length == 0) {
710 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
711 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
712 > MAX_EMPTY_RECORDS) {
713 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
714 SSL_R_RECORD_TOO_SMALL);
718 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
722 if (s->early_data_state == SSL_EARLY_DATA_READING) {
724 if (thisrr->type == SSL3_RT_APPLICATION_DATA
725 && !early_data_count_ok(s, thisrr->length, 0, 0)) {
726 /* SSLfatal already called */
731 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
735 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
737 #ifndef OPENSSL_NO_COMP
740 if (rr->comp == NULL) {
741 rr->comp = (unsigned char *)
742 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
744 if (rr->comp == NULL)
747 /* TODO(size_t): Convert this call */
748 i = COMP_expand_block(ssl->expand, rr->comp,
749 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
759 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
761 #ifndef OPENSSL_NO_COMP
764 /* TODO(size_t): Convert this call */
765 i = COMP_compress_block(ssl->compress, wr->data,
766 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
767 wr->input, (int)wr->length);
773 wr->input = wr->data;
779 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
782 * 0: (in non-constant time) if the record is publically invalid (i.e. too
784 * 1: if the record's padding is valid / the encryption was successful.
785 * -1: if the record's padding is invalid or, if sending, an internal error
788 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
793 size_t bs, mac_size = 0;
795 const EVP_CIPHER *enc;
799 * We shouldn't ever be called with more than one record in the SSLv3 case
804 ds = s->enc_write_ctx;
805 if (s->enc_write_ctx == NULL)
808 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
810 ds = s->enc_read_ctx;
811 if (s->enc_read_ctx == NULL)
814 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
817 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
818 memmove(rec->data, rec->input, rec->length);
819 rec->input = rec->data;
822 /* TODO(size_t): Convert this call */
823 bs = EVP_CIPHER_CTX_block_size(ds);
827 if ((bs != 1) && sending) {
830 /* we need to add 'i-1' padding bytes */
833 * the last of these zero bytes will be overwritten with the
836 memset(&rec->input[rec->length], 0, i);
838 rec->input[l - 1] = (unsigned char)(i - 1);
842 if (l == 0 || l % bs != 0)
844 /* otherwise, rec->length >= bs */
847 /* TODO(size_t): Convert this call */
848 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
851 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
852 /* TODO(size_t): convert me */
853 imac_size = EVP_MD_CTX_size(s->read_hash);
856 mac_size = (size_t)imac_size;
858 if ((bs != 1) && !sending)
859 return ssl3_cbc_remove_padding(rec, bs, mac_size);
864 #define MAX_PADDING 256
866 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
869 * 0: (in non-constant time) if the record is publically invalid (i.e. too
871 * 1: if the record's padding is valid / the encryption was successful.
872 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
873 * an internal error occurred.
875 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
878 size_t reclen[SSL_MAX_PIPELINES];
879 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
880 int i, pad = 0, ret, tmpr;
881 size_t bs, mac_size = 0, ctr, padnum, loop;
882 unsigned char padval;
884 const EVP_CIPHER *enc;
890 if (EVP_MD_CTX_md(s->write_hash)) {
891 int n = EVP_MD_CTX_size(s->write_hash);
892 if (!ossl_assert(n >= 0)) {
893 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
897 ds = s->enc_write_ctx;
898 if (s->enc_write_ctx == NULL)
902 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
903 /* For TLSv1.1 and later explicit IV */
904 if (SSL_USE_EXPLICIT_IV(s)
905 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
906 ivlen = EVP_CIPHER_iv_length(enc);
910 for (ctr = 0; ctr < n_recs; ctr++) {
911 if (recs[ctr].data != recs[ctr].input) {
913 * we can't write into the input stream: Can this ever
916 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
918 } else if (ssl_randbytes(s, recs[ctr].input, ivlen) <= 0) {
919 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
926 if (EVP_MD_CTX_md(s->read_hash)) {
927 int n = EVP_MD_CTX_size(s->read_hash);
928 if (!ossl_assert(n >= 0)) {
929 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
933 ds = s->enc_read_ctx;
934 if (s->enc_read_ctx == NULL)
937 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
940 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
941 for (ctr = 0; ctr < n_recs; ctr++) {
942 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
943 recs[ctr].input = recs[ctr].data;
947 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
950 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
951 & EVP_CIPH_FLAG_PIPELINE)) {
953 * We shouldn't have been called with pipeline data if the
954 * cipher doesn't support pipelining
956 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
960 for (ctr = 0; ctr < n_recs; ctr++) {
961 reclen[ctr] = recs[ctr].length;
963 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
964 & EVP_CIPH_FLAG_AEAD_CIPHER) {
967 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
968 : RECORD_LAYER_get_read_sequence(&s->rlayer);
970 if (SSL_IS_DTLS(s)) {
971 /* DTLS does not support pipelining */
972 unsigned char dtlsseq[9], *p = dtlsseq;
974 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
975 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
976 memcpy(p, &seq[2], 6);
977 memcpy(buf[ctr], dtlsseq, 8);
979 memcpy(buf[ctr], seq, 8);
980 for (i = 7; i >= 0; i--) { /* increment */
987 buf[ctr][8] = recs[ctr].type;
988 buf[ctr][9] = (unsigned char)(s->version >> 8);
989 buf[ctr][10] = (unsigned char)(s->version);
990 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
991 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
992 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
993 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
999 recs[ctr].length += pad;
1002 } else if ((bs != 1) && sending) {
1003 padnum = bs - (reclen[ctr] % bs);
1005 /* Add weird padding of upto 256 bytes */
1007 if (padnum > MAX_PADDING)
1009 /* we need to add 'padnum' padding bytes of value padval */
1010 padval = (unsigned char)(padnum - 1);
1011 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
1012 recs[ctr].input[loop] = padval;
1013 reclen[ctr] += padnum;
1014 recs[ctr].length += padnum;
1018 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
1023 unsigned char *data[SSL_MAX_PIPELINES];
1025 /* Set the output buffers */
1026 for (ctr = 0; ctr < n_recs; ctr++) {
1027 data[ctr] = recs[ctr].data;
1029 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
1030 (int)n_recs, data) <= 0) {
1031 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1033 /* Set the input buffers */
1034 for (ctr = 0; ctr < n_recs; ctr++) {
1035 data[ctr] = recs[ctr].input;
1037 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
1038 (int)n_recs, data) <= 0
1039 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1040 (int)n_recs, reclen) <= 0) {
1041 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1046 /* TODO(size_t): Convert this call */
1047 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1048 (unsigned int)reclen[0]);
1049 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1050 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1053 return -1; /* AEAD can fail to verify MAC */
1055 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1056 for (ctr = 0; ctr < n_recs; ctr++) {
1057 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1058 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1059 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1061 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1062 for (ctr = 0; ctr < n_recs; ctr++) {
1063 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1064 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1065 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1071 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1072 imac_size = EVP_MD_CTX_size(s->read_hash);
1075 mac_size = (size_t)imac_size;
1077 if ((bs != 1) && !sending) {
1079 for (ctr = 0; ctr < n_recs; ctr++) {
1080 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1082 * If tmpret == 0 then this means publicly invalid so we can
1083 * short circuit things here. Otherwise we must respect constant
1088 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1092 if (pad && !sending) {
1093 for (ctr = 0; ctr < n_recs; ctr++) {
1094 recs[ctr].length -= pad;
1101 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1103 unsigned char *mac_sec, *seq;
1104 const EVP_MD_CTX *hash;
1105 unsigned char *p, rec_char;
1111 mac_sec = &(ssl->s3->write_mac_secret[0]);
1112 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1113 hash = ssl->write_hash;
1115 mac_sec = &(ssl->s3->read_mac_secret[0]);
1116 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1117 hash = ssl->read_hash;
1120 t = EVP_MD_CTX_size(hash);
1124 npad = (48 / md_size) * md_size;
1127 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1128 ssl3_cbc_record_digest_supported(hash)) {
1130 * This is a CBC-encrypted record. We must avoid leaking any
1131 * timing-side channel information about how many blocks of data we
1132 * are hashing because that gives an attacker a timing-oracle.
1136 * npad is, at most, 48 bytes and that's with MD5:
1137 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1139 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1140 * goes up 4, but npad goes down by 8, resulting in a smaller
1143 unsigned char header[75];
1145 memcpy(header + j, mac_sec, md_size);
1147 memcpy(header + j, ssl3_pad_1, npad);
1149 memcpy(header + j, seq, 8);
1151 header[j++] = rec->type;
1152 header[j++] = (unsigned char)(rec->length >> 8);
1153 header[j++] = (unsigned char)(rec->length & 0xff);
1155 /* Final param == is SSLv3 */
1156 if (ssl3_cbc_digest_record(hash,
1159 rec->length + md_size, rec->orig_len,
1160 mac_sec, md_size, 1) <= 0)
1163 unsigned int md_size_u;
1164 /* Chop the digest off the end :-) */
1165 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1170 rec_char = rec->type;
1172 s2n(rec->length, p);
1173 if (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_1, npad) <= 0
1176 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1177 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1178 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1179 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1180 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1181 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1182 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1183 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1184 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1185 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1186 EVP_MD_CTX_reset(md_ctx);
1190 EVP_MD_CTX_free(md_ctx);
1193 ssl3_record_sequence_update(seq);
1197 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1203 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1204 unsigned char header[13];
1205 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1206 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1210 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1211 hash = ssl->write_hash;
1213 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1214 hash = ssl->read_hash;
1217 t = EVP_MD_CTX_size(hash);
1218 if (!ossl_assert(t >= 0))
1222 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1226 hmac = EVP_MD_CTX_new();
1227 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1232 if (SSL_IS_DTLS(ssl)) {
1233 unsigned char dtlsseq[8], *p = dtlsseq;
1235 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1236 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1237 memcpy(p, &seq[2], 6);
1239 memcpy(header, dtlsseq, 8);
1241 memcpy(header, seq, 8);
1243 header[8] = rec->type;
1244 header[9] = (unsigned char)(ssl->version >> 8);
1245 header[10] = (unsigned char)(ssl->version);
1246 header[11] = (unsigned char)(rec->length >> 8);
1247 header[12] = (unsigned char)(rec->length & 0xff);
1249 if (!sending && !SSL_READ_ETM(ssl) &&
1250 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1251 ssl3_cbc_record_digest_supported(mac_ctx)) {
1253 * This is a CBC-encrypted record. We must avoid leaking any
1254 * timing-side channel information about how many blocks of data we
1255 * are hashing because that gives an attacker a timing-oracle.
1257 /* Final param == not SSLv3 */
1258 if (ssl3_cbc_digest_record(mac_ctx,
1261 rec->length + md_size, rec->orig_len,
1262 ssl->s3->read_mac_secret,
1263 ssl->s3->read_mac_secret_size, 0) <= 0) {
1264 EVP_MD_CTX_free(hmac);
1268 /* TODO(size_t): Convert these calls */
1269 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1270 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1271 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1272 EVP_MD_CTX_free(hmac);
1277 EVP_MD_CTX_free(hmac);
1280 fprintf(stderr, "seq=");
1283 for (z = 0; z < 8; z++)
1284 fprintf(stderr, "%02X ", seq[z]);
1285 fprintf(stderr, "\n");
1287 fprintf(stderr, "rec=");
1290 for (z = 0; z < rec->length; z++)
1291 fprintf(stderr, "%02X ", rec->data[z]);
1292 fprintf(stderr, "\n");
1296 if (!SSL_IS_DTLS(ssl)) {
1297 for (i = 7; i >= 0; i--) {
1306 for (z = 0; z < md_size; z++)
1307 fprintf(stderr, "%02X ", md[z]);
1308 fprintf(stderr, "\n");
1315 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1316 * record in |rec| by updating |rec->length| in constant time.
1318 * block_size: the block size of the cipher used to encrypt the record.
1320 * 0: (in non-constant time) if the record is publicly invalid.
1321 * 1: if the padding was valid
1324 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1325 size_t block_size, size_t mac_size)
1327 size_t padding_length;
1329 const size_t overhead = 1 /* padding length byte */ + mac_size;
1332 * These lengths are all public so we can test them in non-constant time.
1334 if (overhead > rec->length)
1337 padding_length = rec->data[rec->length - 1];
1338 good = constant_time_ge_s(rec->length, padding_length + overhead);
1339 /* SSLv3 requires that the padding is minimal. */
1340 good &= constant_time_ge_s(block_size, padding_length + 1);
1341 rec->length -= good & (padding_length + 1);
1342 return constant_time_select_int_s(good, 1, -1);
1346 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1347 * record in |rec| in constant time and returns 1 if the padding is valid and
1348 * -1 otherwise. It also removes any explicit IV from the start of the record
1349 * without leaking any timing about whether there was enough space after the
1350 * padding was removed.
1352 * block_size: the block size of the cipher used to encrypt the record.
1354 * 0: (in non-constant time) if the record is publicly invalid.
1355 * 1: if the padding was valid
1358 int tls1_cbc_remove_padding(const SSL *s,
1360 size_t block_size, size_t mac_size)
1363 size_t padding_length, to_check, i;
1364 const size_t overhead = 1 /* padding length byte */ + mac_size;
1365 /* Check if version requires explicit IV */
1366 if (SSL_USE_EXPLICIT_IV(s)) {
1368 * These lengths are all public so we can test them in non-constant
1371 if (overhead + block_size > rec->length)
1373 /* We can now safely skip explicit IV */
1374 rec->data += block_size;
1375 rec->input += block_size;
1376 rec->length -= block_size;
1377 rec->orig_len -= block_size;
1378 } else if (overhead > rec->length)
1381 padding_length = rec->data[rec->length - 1];
1383 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1384 EVP_CIPH_FLAG_AEAD_CIPHER) {
1385 /* padding is already verified */
1386 rec->length -= padding_length + 1;
1390 good = constant_time_ge_s(rec->length, overhead + padding_length);
1392 * The padding consists of a length byte at the end of the record and
1393 * then that many bytes of padding, all with the same value as the length
1394 * byte. Thus, with the length byte included, there are i+1 bytes of
1395 * padding. We can't check just |padding_length+1| bytes because that
1396 * leaks decrypted information. Therefore we always have to check the
1397 * maximum amount of padding possible. (Again, the length of the record
1398 * is public information so we can use it.)
1400 to_check = 256; /* maximum amount of padding, inc length byte. */
1401 if (to_check > rec->length)
1402 to_check = rec->length;
1404 for (i = 0; i < to_check; i++) {
1405 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1406 unsigned char b = rec->data[rec->length - 1 - i];
1408 * The final |padding_length+1| bytes should all have the value
1409 * |padding_length|. Therefore the XOR should be zero.
1411 good &= ~(mask & (padding_length ^ b));
1415 * If any of the final |padding_length+1| bytes had the wrong value, one
1416 * or more of the lower eight bits of |good| will be cleared.
1418 good = constant_time_eq_s(0xff, good & 0xff);
1419 rec->length -= good & (padding_length + 1);
1421 return constant_time_select_int_s(good, 1, -1);
1425 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1426 * constant time (independent of the concrete value of rec->length, which may
1427 * vary within a 256-byte window).
1429 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1433 * rec->orig_len >= md_size
1434 * md_size <= EVP_MAX_MD_SIZE
1436 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1437 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1438 * a single or pair of cache-lines, then the variable memory accesses don't
1439 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1440 * not multi-core and are not considered vulnerable to cache-timing attacks.
1442 #define CBC_MAC_ROTATE_IN_PLACE
1444 int ssl3_cbc_copy_mac(unsigned char *out,
1445 const SSL3_RECORD *rec, size_t md_size)
1447 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1448 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1449 unsigned char *rotated_mac;
1451 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1455 * mac_end is the index of |rec->data| just after the end of the MAC.
1457 size_t mac_end = rec->length;
1458 size_t mac_start = mac_end - md_size;
1461 * scan_start contains the number of bytes that we can ignore because the
1462 * MAC's position can only vary by 255 bytes.
1464 size_t scan_start = 0;
1466 size_t rotate_offset;
1468 if (!ossl_assert(rec->orig_len >= md_size
1469 && md_size <= EVP_MAX_MD_SIZE))
1472 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1473 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1476 /* This information is public so it's safe to branch based on it. */
1477 if (rec->orig_len > md_size + 255 + 1)
1478 scan_start = rec->orig_len - (md_size + 255 + 1);
1482 memset(rotated_mac, 0, md_size);
1483 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1484 size_t mac_started = constant_time_eq_s(i, mac_start);
1485 size_t mac_ended = constant_time_lt_s(i, mac_end);
1486 unsigned char b = rec->data[i];
1488 in_mac |= mac_started;
1489 in_mac &= mac_ended;
1490 rotate_offset |= j & mac_started;
1491 rotated_mac[j++] |= b & in_mac;
1492 j &= constant_time_lt_s(j, md_size);
1495 /* Now rotate the MAC */
1496 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1498 for (i = 0; i < md_size; i++) {
1499 /* in case cache-line is 32 bytes, touch second line */
1500 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1501 out[j++] = rotated_mac[rotate_offset++];
1502 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1505 memset(out, 0, md_size);
1506 rotate_offset = md_size - rotate_offset;
1507 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1508 for (i = 0; i < md_size; i++) {
1509 for (j = 0; j < md_size; j++)
1510 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1512 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1519 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1527 unsigned char md[EVP_MAX_MD_SIZE];
1529 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1533 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1534 * and we have that many bytes in s->packet
1536 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1539 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1540 * at rr->length bytes, which need to be copied into rr->data by either
1541 * the decryption or by the decompression When the data is 'copied' into
1542 * the rr->data buffer, rr->input will be pointed at the new buffer
1546 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1547 * bytes of encrypted compressed stuff.
1550 /* check is not needed I believe */
1551 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1552 al = SSL_AD_RECORD_OVERFLOW;
1553 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1557 /* decrypt in place in 'rr->input' */
1558 rr->data = rr->input;
1559 rr->orig_len = rr->length;
1561 if (SSL_READ_ETM(s) && s->read_hash) {
1563 mac_size = EVP_MD_CTX_size(s->read_hash);
1564 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1565 al = SSL_AD_INTERNAL_ERROR;
1566 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1569 if (rr->orig_len < mac_size) {
1570 al = SSL_AD_DECODE_ERROR;
1571 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1574 rr->length -= mac_size;
1575 mac = rr->data + rr->length;
1576 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1577 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1578 al = SSL_AD_BAD_RECORD_MAC;
1579 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1580 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1585 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1588 * 0: (in non-constant time) if the record is publically invalid.
1589 * 1: if the padding is valid
1590 * -1: if the padding is invalid
1593 /* For DTLS we simply ignore bad packets. */
1595 RECORD_LAYER_reset_packet_length(&s->rlayer);
1599 printf("dec %ld\n", rr->length);
1602 for (z = 0; z < rr->length; z++)
1603 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1608 /* r->length is now the compressed data plus mac */
1609 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1610 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1611 /* s->read_hash != NULL => mac_size != -1 */
1612 unsigned char *mac = NULL;
1613 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1615 /* TODO(size_t): Convert this to do size_t properly */
1616 imac_size = EVP_MD_CTX_size(s->read_hash);
1617 if (imac_size < 0) {
1618 al = SSL_AD_INTERNAL_ERROR;
1619 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1622 mac_size = (size_t)imac_size;
1623 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1624 al = SSL_AD_INTERNAL_ERROR;
1625 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1630 * orig_len is the length of the record before any padding was
1631 * removed. This is public information, as is the MAC in use,
1632 * therefore we can safely process the record in a different amount
1633 * of time if it's too short to possibly contain a MAC.
1635 if (rr->orig_len < mac_size ||
1636 /* CBC records must have a padding length byte too. */
1637 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1638 rr->orig_len < mac_size + 1)) {
1639 al = SSL_AD_DECODE_ERROR;
1640 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1644 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1646 * We update the length so that the TLS header bytes can be
1647 * constructed correctly but we need to extract the MAC in
1648 * constant time from within the record, without leaking the
1649 * contents of the padding bytes.
1652 if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
1653 al = SSL_AD_INTERNAL_ERROR;
1654 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1657 rr->length -= mac_size;
1660 * In this case there's no padding, so |rec->orig_len| equals
1661 * |rec->length| and we checked that there's enough bytes for
1664 rr->length -= mac_size;
1665 mac = &rr->data[rr->length];
1668 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1669 if (i == 0 || mac == NULL
1670 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1672 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1677 /* decryption failed, silently discard message */
1679 RECORD_LAYER_reset_packet_length(&s->rlayer);
1683 /* r->length is now just compressed */
1684 if (s->expand != NULL) {
1685 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1686 al = SSL_AD_RECORD_OVERFLOW;
1687 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1688 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1691 if (!ssl3_do_uncompress(s, rr)) {
1692 al = SSL_AD_DECOMPRESSION_FAILURE;
1693 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1698 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1699 al = SSL_AD_RECORD_OVERFLOW;
1700 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1706 * So at this point the following is true
1707 * ssl->s3->rrec.type is the type of record
1708 * ssl->s3->rrec.length == number of bytes in record
1709 * ssl->s3->rrec.off == offset to first valid byte
1710 * ssl->s3->rrec.data == where to take bytes from, increment
1714 /* we have pulled in a full packet so zero things */
1715 RECORD_LAYER_reset_packet_length(&s->rlayer);
1717 /* Mark receipt of record. */
1718 dtls1_record_bitmap_update(s, bitmap);
1723 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1729 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1731 #define dtls1_get_processed_record(s) \
1732 dtls1_retrieve_buffered_record((s), \
1733 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1736 * Call this to get a new input record.
1737 * It will return <= 0 if more data is needed, normally due to an error
1738 * or non-blocking IO.
1739 * When it finishes, one packet has been decoded and can be found in
1740 * ssl->s3->rrec.type - is the type of record
1741 * ssl->s3->rrec.data, - data
1742 * ssl->s3->rrec.length, - number of bytes
1744 /* used only by dtls1_read_bytes */
1745 int dtls1_get_record(SSL *s)
1747 int ssl_major, ssl_minor;
1751 unsigned char *p = NULL;
1752 unsigned short version;
1753 DTLS1_BITMAP *bitmap;
1754 unsigned int is_next_epoch;
1756 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1760 * The epoch may have changed. If so, process all the pending records.
1761 * This is a non-blocking operation.
1763 if (!dtls1_process_buffered_records(s))
1766 /* if we're renegotiating, then there may be buffered records */
1767 if (dtls1_get_processed_record(s))
1770 /* get something from the wire */
1772 /* check if we have the header */
1773 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1774 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1775 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1776 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1777 /* read timeout is handled by dtls1_read_bytes */
1779 return rret; /* error or non-blocking */
1781 /* this packet contained a partial record, dump it */
1782 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1783 DTLS1_RT_HEADER_LENGTH) {
1784 RECORD_LAYER_reset_packet_length(&s->rlayer);
1788 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1790 p = RECORD_LAYER_get_packet(&s->rlayer);
1792 if (s->msg_callback)
1793 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1794 s, s->msg_callback_arg);
1796 /* Pull apart the header into the DTLS1_RECORD */
1800 version = (ssl_major << 8) | ssl_minor;
1802 /* sequence number is 64 bits, with top 2 bytes = epoch */
1805 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1810 /* Lets check version */
1811 if (!s->first_packet) {
1812 if (version != s->version) {
1813 /* unexpected version, silently discard */
1815 RECORD_LAYER_reset_packet_length(&s->rlayer);
1820 if ((version & 0xff00) != (s->version & 0xff00)) {
1821 /* wrong version, silently discard record */
1823 RECORD_LAYER_reset_packet_length(&s->rlayer);
1827 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1828 /* record too long, silently discard it */
1830 RECORD_LAYER_reset_packet_length(&s->rlayer);
1834 /* If received packet overflows own-client Max Fragment Length setting */
1835 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
1836 && rr->length > GET_MAX_FRAGMENT_LENGTH(s->session)) {
1837 /* record too long, silently discard it */
1839 RECORD_LAYER_reset_packet_length(&s->rlayer);
1843 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1846 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1849 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1850 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1852 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1853 /* this packet contained a partial record, dump it */
1854 if (rret <= 0 || n != more) {
1856 RECORD_LAYER_reset_packet_length(&s->rlayer);
1861 * now n == rr->length, and s->packet_length ==
1862 * DTLS1_RT_HEADER_LENGTH + rr->length
1865 /* set state for later operations */
1866 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1868 /* match epochs. NULL means the packet is dropped on the floor */
1869 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1870 if (bitmap == NULL) {
1872 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1873 goto again; /* get another record */
1875 #ifndef OPENSSL_NO_SCTP
1876 /* Only do replay check if no SCTP bio */
1877 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1879 /* Check whether this is a repeat, or aged record. */
1881 * TODO: Does it make sense to have replay protection in epoch 0 where
1882 * we have no integrity negotiated yet?
1884 if (!dtls1_record_replay_check(s, bitmap)) {
1886 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1887 goto again; /* get another record */
1889 #ifndef OPENSSL_NO_SCTP
1893 /* just read a 0 length packet */
1894 if (rr->length == 0)
1898 * If this record is from the next epoch (either HM or ALERT), and a
1899 * handshake is currently in progress, buffer it since it cannot be
1900 * processed at this time.
1902 if (is_next_epoch) {
1903 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1904 if (dtls1_buffer_record
1905 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1910 RECORD_LAYER_reset_packet_length(&s->rlayer);
1914 if (!dtls1_process_record(s, bitmap)) {
1916 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1917 goto again; /* get another record */