2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "../ssl_locl.h"
11 #include "internal/constant_time_locl.h"
12 #include <openssl/rand.h>
13 #include "record_locl.h"
14 #include "internal/cryptlib.h"
16 static const unsigned char ssl3_pad_1[48] = {
17 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
18 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
19 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
20 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
21 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
22 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36
25 static const unsigned char ssl3_pad_2[48] = {
26 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
27 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
28 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
29 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
30 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
31 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c
35 * Clear the contents of an SSL3_RECORD but retain any memory allocated
37 void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
42 for (i = 0; i < num_recs; i++) {
45 memset(&r[i], 0, sizeof(*r));
50 void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
54 for (i = 0; i < num_recs; i++) {
55 OPENSSL_free(r[i].comp);
60 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
62 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
66 * Peeks ahead into "read_ahead" data to see if we have a whole record waiting
67 * for us in the buffer.
69 static int ssl3_record_app_data_waiting(SSL *s)
75 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
77 p = SSL3_BUFFER_get_buf(rbuf);
81 left = SSL3_BUFFER_get_left(rbuf);
83 if (left < SSL3_RT_HEADER_LENGTH)
86 p += SSL3_BUFFER_get_offset(rbuf);
89 * We only check the type and record length, we will sanity check version
92 if (*p != SSL3_RT_APPLICATION_DATA)
98 if (left < SSL3_RT_HEADER_LENGTH + len)
104 int early_data_count_ok(SSL *s, size_t length, size_t overhead, int *al)
106 uint32_t max_early_data = s->max_early_data;
109 * If we are a client then we always use the max_early_data from the
110 * session. Otherwise we go with the lowest out of the max early data set in
111 * the session and the configured max_early_data.
113 if (!s->server || (s->hit
114 && s->session->ext.max_early_data < s->max_early_data))
115 max_early_data = s->session->ext.max_early_data;
117 if (max_early_data == 0) {
119 *al = SSL_AD_UNEXPECTED_MESSAGE;
120 SSLerr(SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
124 /* If we are dealing with ciphertext we need to allow for the overhead */
125 max_early_data += overhead;
127 if (s->early_data_count + length > max_early_data) {
129 *al = SSL_AD_UNEXPECTED_MESSAGE;
130 SSLerr(SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
133 s->early_data_count += length;
139 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
140 * will be processed per call to ssl3_get_record. Without this limit an
141 * attacker could send empty records at a faster rate than we can process and
142 * cause ssl3_get_record to loop forever.
144 #define MAX_EMPTY_RECORDS 32
146 #define SSL2_RT_HEADER_LENGTH 2
148 * Call this to get new input records.
149 * It will return <= 0 if more data is needed, normally due to an error
150 * or non-blocking IO.
151 * When it finishes, |numrpipes| records have been decoded. For each record 'i':
152 * rr[i].type - is the type of record
154 * rr[i].length, - number of bytes
155 * Multiple records will only be returned if the record types are all
156 * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
159 /* used only by ssl3_read_bytes */
160 int ssl3_get_record(SSL *s)
163 int enc_err, rret, ret = -1;
166 SSL3_RECORD *rr, *thisrr;
170 unsigned char md[EVP_MAX_MD_SIZE];
171 unsigned int version;
174 size_t num_recs = 0, max_recs, j;
175 PACKET pkt, sslv2pkt;
176 size_t first_rec_len;
178 rr = RECORD_LAYER_get_rrec(&s->rlayer);
179 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
180 max_recs = s->max_pipelines;
186 thisrr = &rr[num_recs];
188 /* check if we have the header */
189 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
190 (RECORD_LAYER_get_packet_length(&s->rlayer)
191 < SSL3_RT_HEADER_LENGTH)) {
195 rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
196 SSL3_BUFFER_get_len(rbuf), 0,
197 num_recs == 0 ? 1 : 0, &n);
199 return rret; /* error or non-blocking */
200 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
202 p = RECORD_LAYER_get_packet(&s->rlayer);
203 if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
204 RECORD_LAYER_get_packet_length(&s->rlayer))) {
205 al = SSL_AD_INTERNAL_ERROR;
206 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
210 if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
211 || !PACKET_get_1(&sslv2pkt, &type)) {
212 al = SSL_AD_DECODE_ERROR;
213 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
217 * The first record received by the server may be a V2ClientHello.
219 if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
220 && (sslv2len & 0x8000) != 0
221 && (type == SSL2_MT_CLIENT_HELLO)) {
225 * |num_recs| here will actually always be 0 because
226 * |num_recs > 0| only ever occurs when we are processing
227 * multiple app data records - which we know isn't the case here
228 * because it is an SSLv2ClientHello. We keep it using
229 * |num_recs| for the sake of consistency
231 thisrr->type = SSL3_RT_HANDSHAKE;
232 thisrr->rec_version = SSL2_VERSION;
234 thisrr->length = sslv2len & 0x7fff;
236 if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
237 - SSL2_RT_HEADER_LENGTH) {
238 al = SSL_AD_RECORD_OVERFLOW;
239 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
243 if (thisrr->length < MIN_SSL2_RECORD_LEN) {
244 al = SSL_AD_DECODE_ERROR;
245 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
249 /* SSLv3+ style record */
251 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
252 s->msg_callback_arg);
254 /* Pull apart the header into the SSL3_RECORD */
255 if (!PACKET_get_1(&pkt, &type)
256 || !PACKET_get_net_2(&pkt, &version)
257 || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
258 al = SSL_AD_DECODE_ERROR;
259 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
263 thisrr->rec_version = version;
265 /* Lets check version. In TLSv1.3 we ignore this field */
266 if (!s->first_packet && !SSL_IS_TLS13(s)
267 && version != (unsigned int)s->version) {
268 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
269 if ((s->version & 0xFF00) == (version & 0xFF00)
270 && !s->enc_write_ctx && !s->write_hash) {
271 if (thisrr->type == SSL3_RT_ALERT) {
273 * The record is using an incorrect version number,
274 * but what we've got appears to be an alert. We
275 * haven't read the body yet to check whether its a
276 * fatal or not - but chances are it is. We probably
277 * shouldn't send a fatal alert back. We'll just
283 * Send back error using their minor version number :-)
285 s->version = (unsigned short)version;
287 al = SSL_AD_PROTOCOL_VERSION;
291 if ((version >> 8) != SSL3_VERSION_MAJOR) {
292 if (RECORD_LAYER_is_first_record(&s->rlayer)) {
293 /* Go back to start of packet, look at the five bytes
295 p = RECORD_LAYER_get_packet(&s->rlayer);
296 if (strncmp((char *)p, "GET ", 4) == 0 ||
297 strncmp((char *)p, "POST ", 5) == 0 ||
298 strncmp((char *)p, "HEAD ", 5) == 0 ||
299 strncmp((char *)p, "PUT ", 4) == 0) {
300 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_HTTP_REQUEST);
302 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
303 SSLerr(SSL_F_SSL3_GET_RECORD,
304 SSL_R_HTTPS_PROXY_REQUEST);
308 /* Doesn't look like TLS - don't send an alert */
309 SSLerr(SSL_F_SSL3_GET_RECORD,
310 SSL_R_WRONG_VERSION_NUMBER);
313 SSLerr(SSL_F_SSL3_GET_RECORD,
314 SSL_R_WRONG_VERSION_NUMBER);
315 al = SSL_AD_PROTOCOL_VERSION;
320 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL
321 && thisrr->type != SSL3_RT_APPLICATION_DATA) {
322 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
323 al = SSL_AD_UNEXPECTED_MESSAGE;
328 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
329 al = SSL_AD_RECORD_OVERFLOW;
330 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
335 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
338 if (SSL_IS_TLS13(s)) {
339 if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
340 al = SSL_AD_RECORD_OVERFLOW;
341 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
345 size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
347 #ifndef OPENSSL_NO_COMP
349 * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
350 * does not include the compression overhead anyway.
352 if (s->expand == NULL)
353 len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
356 if (thisrr->length > len) {
357 al = SSL_AD_RECORD_OVERFLOW;
358 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
364 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
365 * Calculate how much more data we need to read for the rest of the
368 if (thisrr->rec_version == SSL2_VERSION) {
369 more = thisrr->length + SSL2_RT_HEADER_LENGTH
370 - SSL3_RT_HEADER_LENGTH;
372 more = thisrr->length;
375 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
377 rret = ssl3_read_n(s, more, more, 1, 0, &n);
379 return rret; /* error or non-blocking io */
382 /* set state for later operations */
383 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
386 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH
387 * + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
388 * + thisrr->length and we have that many bytes in s->packet
390 if (thisrr->rec_version == SSL2_VERSION) {
392 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
395 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
399 * ok, we can now read from 's->packet' data into 'thisrr' thisrr->input
400 * points at thisrr->length bytes, which need to be copied into
401 * thisrr->data by either the decryption or by the decompression When
402 * the data is 'copied' into the thisrr->data buffer, thisrr->input will
403 * be pointed at the new buffer
407 * We now have - encrypted [ MAC [ compressed [ plain ] ] ]
408 * thisrr->length bytes of encrypted compressed stuff.
411 /* decrypt in place in 'thisrr->input' */
412 thisrr->data = thisrr->input;
413 thisrr->orig_len = thisrr->length;
415 /* Mark this record as not read by upper layers yet */
420 /* we have pulled in a full packet so zero things */
421 RECORD_LAYER_reset_packet_length(&s->rlayer);
422 RECORD_LAYER_clear_first_record(&s->rlayer);
423 } while (num_recs < max_recs
424 && thisrr->type == SSL3_RT_APPLICATION_DATA
425 && SSL_USE_EXPLICIT_IV(s)
426 && s->enc_read_ctx != NULL
427 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
428 & EVP_CIPH_FLAG_PIPELINE)
429 && ssl3_record_app_data_waiting(s));
432 * If in encrypt-then-mac mode calculate mac from encrypted record. All
433 * the details below are public so no timing details can leak.
435 if (SSL_READ_ETM(s) && s->read_hash) {
437 /* TODO(size_t): convert this to do size_t properly */
438 imac_size = EVP_MD_CTX_size(s->read_hash);
439 if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
440 al = SSL_AD_INTERNAL_ERROR;
441 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_LIB_EVP);
444 mac_size = (size_t)imac_size;
445 for (j = 0; j < num_recs; j++) {
448 if (thisrr->length < mac_size) {
449 al = SSL_AD_DECODE_ERROR;
450 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
453 thisrr->length -= mac_size;
454 mac = thisrr->data + thisrr->length;
455 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
456 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
457 al = SSL_AD_BAD_RECORD_MAC;
458 SSLerr(SSL_F_SSL3_GET_RECORD,
459 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
465 first_rec_len = rr[0].length;
467 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
471 * 0: (in non-constant time) if the record is publicly invalid.
472 * 1: if the padding is valid
473 * -1: if the padding is invalid
476 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
478 * Valid early_data that we cannot decrypt might fail here as
479 * publicly invalid. We treat it like an empty record.
484 if (!early_data_count_ok(s, thisrr->length,
485 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
490 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
491 RECORD_LAYER_reset_read_sequence(&s->rlayer);
494 al = SSL_AD_DECRYPTION_FAILED;
495 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
499 printf("dec %"OSSLzu"\n", rr[0].length);
502 for (z = 0; z < rr[0].length; z++)
503 printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
508 /* r->length is now the compressed data plus mac */
509 if ((sess != NULL) &&
510 (s->enc_read_ctx != NULL) &&
511 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
512 /* s->read_hash != NULL => mac_size != -1 */
513 unsigned char *mac = NULL;
514 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
516 mac_size = EVP_MD_CTX_size(s->read_hash);
517 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
518 al = SSL_AD_INTERNAL_ERROR;
519 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
523 for (j = 0; j < num_recs; j++) {
526 * orig_len is the length of the record before any padding was
527 * removed. This is public information, as is the MAC in use,
528 * therefore we can safely process the record in a different amount
529 * of time if it's too short to possibly contain a MAC.
531 if (thisrr->orig_len < mac_size ||
532 /* CBC records must have a padding length byte too. */
533 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
534 thisrr->orig_len < mac_size + 1)) {
535 al = SSL_AD_DECODE_ERROR;
536 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
540 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
542 * We update the length so that the TLS header bytes can be
543 * constructed correctly but we need to extract the MAC in
544 * constant time from within the record, without leaking the
545 * contents of the padding bytes.
548 if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
549 al = SSL_AD_INTERNAL_ERROR;
550 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
553 thisrr->length -= mac_size;
556 * In this case there's no padding, so |rec->orig_len| equals
557 * |rec->length| and we checked that there's enough bytes for
560 thisrr->length -= mac_size;
561 mac = &thisrr->data[thisrr->length];
564 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
565 if (i == 0 || mac == NULL
566 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
568 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
574 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
576 * We assume this is unreadable early_data - we treat it like an
581 * The record length may have been modified by the mac check above
582 * so we use the previously saved value
584 if (!early_data_count_ok(s, first_rec_len,
585 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
591 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
592 RECORD_LAYER_reset_read_sequence(&s->rlayer);
596 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
597 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
598 * failure is directly visible from the ciphertext anyway, we should
599 * not reveal which kind of error occurred -- this might become
600 * visible to an attacker (e.g. via a logfile)
602 al = SSL_AD_BAD_RECORD_MAC;
603 SSLerr(SSL_F_SSL3_GET_RECORD,
604 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
608 for (j = 0; j < num_recs; j++) {
611 /* thisrr->length is now just compressed */
612 if (s->expand != NULL) {
613 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
614 al = SSL_AD_RECORD_OVERFLOW;
615 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
618 if (!ssl3_do_uncompress(s, thisrr)) {
619 al = SSL_AD_DECOMPRESSION_FAILURE;
620 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
625 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
628 if (thisrr->length == 0
629 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
630 al = SSL_AD_UNEXPECTED_MESSAGE;
631 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
635 /* Strip trailing padding */
636 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
640 thisrr->length = end;
641 thisrr->type = thisrr->data[end];
642 if (thisrr->type != SSL3_RT_APPLICATION_DATA
643 && thisrr->type != SSL3_RT_ALERT
644 && thisrr->type != SSL3_RT_HANDSHAKE) {
645 al = SSL_AD_UNEXPECTED_MESSAGE;
646 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
650 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
651 &thisrr->data[end], 1, s, s->msg_callback_arg);
655 * TLSv1.3 alert and handshake records are required to be non-zero in
659 && (thisrr->type == SSL3_RT_HANDSHAKE
660 || thisrr->type == SSL3_RT_ALERT)
661 && thisrr->length == 0) {
662 al = SSL_AD_UNEXPECTED_MESSAGE;
663 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_LENGTH);
667 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
668 al = SSL_AD_RECORD_OVERFLOW;
669 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
675 * So at this point the following is true
676 * thisrr->type is the type of record
677 * thisrr->length == number of bytes in record
678 * thisrr->off == offset to first valid byte
679 * thisrr->data == where to take bytes from, increment after use :-).
682 /* just read a 0 length packet */
683 if (thisrr->length == 0) {
684 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
685 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
686 > MAX_EMPTY_RECORDS) {
687 al = SSL_AD_UNEXPECTED_MESSAGE;
688 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
692 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
696 if (s->early_data_state == SSL_EARLY_DATA_READING) {
698 if (thisrr->type == SSL3_RT_APPLICATION_DATA
699 && !early_data_count_ok(s, thisrr->length, 0, &al))
703 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
707 ssl3_send_alert(s, SSL3_AL_FATAL, al);
712 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
714 #ifndef OPENSSL_NO_COMP
717 if (rr->comp == NULL) {
718 rr->comp = (unsigned char *)
719 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
721 if (rr->comp == NULL)
724 /* TODO(size_t): Convert this call */
725 i = COMP_expand_block(ssl->expand, rr->comp,
726 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
736 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
738 #ifndef OPENSSL_NO_COMP
741 /* TODO(size_t): Convert this call */
742 i = COMP_compress_block(ssl->compress, wr->data,
743 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
744 wr->input, (int)wr->length);
750 wr->input = wr->data;
756 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
759 * 0: (in non-constant time) if the record is publically invalid (i.e. too
761 * 1: if the record's padding is valid / the encryption was successful.
762 * -1: if the record's padding is invalid or, if sending, an internal error
765 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
770 size_t bs, mac_size = 0;
772 const EVP_CIPHER *enc;
776 * We shouldn't ever be called with more than one record in the SSLv3 case
781 ds = s->enc_write_ctx;
782 if (s->enc_write_ctx == NULL)
785 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
787 ds = s->enc_read_ctx;
788 if (s->enc_read_ctx == NULL)
791 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
794 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
795 memmove(rec->data, rec->input, rec->length);
796 rec->input = rec->data;
799 /* TODO(size_t): Convert this call */
800 bs = EVP_CIPHER_CTX_block_size(ds);
804 if ((bs != 1) && sending) {
807 /* we need to add 'i-1' padding bytes */
810 * the last of these zero bytes will be overwritten with the
813 memset(&rec->input[rec->length], 0, i);
815 rec->input[l - 1] = (unsigned char)(i - 1);
819 if (l == 0 || l % bs != 0)
821 /* otherwise, rec->length >= bs */
824 /* TODO(size_t): Convert this call */
825 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
828 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
829 /* TODO(size_t): convert me */
830 imac_size = EVP_MD_CTX_size(s->read_hash);
833 mac_size = (size_t)imac_size;
835 if ((bs != 1) && !sending)
836 return ssl3_cbc_remove_padding(rec, bs, mac_size);
841 #define MAX_PADDING 256
843 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
846 * 0: (in non-constant time) if the record is publically invalid (i.e. too
848 * 1: if the record's padding is valid / the encryption was successful.
849 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
850 * an internal error occurred.
852 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
855 size_t reclen[SSL_MAX_PIPELINES];
856 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
857 int i, pad = 0, ret, tmpr;
858 size_t bs, mac_size = 0, ctr, padnum, loop;
859 unsigned char padval;
861 const EVP_CIPHER *enc;
867 if (EVP_MD_CTX_md(s->write_hash)) {
868 int n = EVP_MD_CTX_size(s->write_hash);
869 if (!ossl_assert(n >= 0)) {
870 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
874 ds = s->enc_write_ctx;
875 if (s->enc_write_ctx == NULL)
879 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
880 /* For TLSv1.1 and later explicit IV */
881 if (SSL_USE_EXPLICIT_IV(s)
882 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
883 ivlen = EVP_CIPHER_iv_length(enc);
887 for (ctr = 0; ctr < n_recs; ctr++) {
888 if (recs[ctr].data != recs[ctr].input) {
890 * we can't write into the input stream: Can this ever
893 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
895 } else if (ssl_randbytes(s, recs[ctr].input, ivlen) <= 0) {
896 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
903 if (EVP_MD_CTX_md(s->read_hash)) {
904 int n = EVP_MD_CTX_size(s->read_hash);
905 if (!ossl_assert(n >= 0)) {
906 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
910 ds = s->enc_read_ctx;
911 if (s->enc_read_ctx == NULL)
914 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
917 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
918 for (ctr = 0; ctr < n_recs; ctr++) {
919 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
920 recs[ctr].input = recs[ctr].data;
924 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
927 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
928 & EVP_CIPH_FLAG_PIPELINE)) {
930 * We shouldn't have been called with pipeline data if the
931 * cipher doesn't support pipelining
933 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
937 for (ctr = 0; ctr < n_recs; ctr++) {
938 reclen[ctr] = recs[ctr].length;
940 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
941 & EVP_CIPH_FLAG_AEAD_CIPHER) {
944 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
945 : RECORD_LAYER_get_read_sequence(&s->rlayer);
947 if (SSL_IS_DTLS(s)) {
948 /* DTLS does not support pipelining */
949 unsigned char dtlsseq[9], *p = dtlsseq;
951 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
952 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
953 memcpy(p, &seq[2], 6);
954 memcpy(buf[ctr], dtlsseq, 8);
956 memcpy(buf[ctr], seq, 8);
957 for (i = 7; i >= 0; i--) { /* increment */
964 buf[ctr][8] = recs[ctr].type;
965 buf[ctr][9] = (unsigned char)(s->version >> 8);
966 buf[ctr][10] = (unsigned char)(s->version);
967 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
968 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
969 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
970 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
976 recs[ctr].length += pad;
979 } else if ((bs != 1) && sending) {
980 padnum = bs - (reclen[ctr] % bs);
982 /* Add weird padding of upto 256 bytes */
984 if (padnum > MAX_PADDING)
986 /* we need to add 'padnum' padding bytes of value padval */
987 padval = (unsigned char)(padnum - 1);
988 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
989 recs[ctr].input[loop] = padval;
990 reclen[ctr] += padnum;
991 recs[ctr].length += padnum;
995 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
1000 unsigned char *data[SSL_MAX_PIPELINES];
1002 /* Set the output buffers */
1003 for (ctr = 0; ctr < n_recs; ctr++) {
1004 data[ctr] = recs[ctr].data;
1006 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
1007 (int)n_recs, data) <= 0) {
1008 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1010 /* Set the input buffers */
1011 for (ctr = 0; ctr < n_recs; ctr++) {
1012 data[ctr] = recs[ctr].input;
1014 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
1015 (int)n_recs, data) <= 0
1016 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1017 (int)n_recs, reclen) <= 0) {
1018 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1023 /* TODO(size_t): Convert this call */
1024 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1025 (unsigned int)reclen[0]);
1026 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1027 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1030 return -1; /* AEAD can fail to verify MAC */
1032 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1033 for (ctr = 0; ctr < n_recs; ctr++) {
1034 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1035 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1036 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1038 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1039 for (ctr = 0; ctr < n_recs; ctr++) {
1040 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1041 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1042 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1048 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1049 imac_size = EVP_MD_CTX_size(s->read_hash);
1052 mac_size = (size_t)imac_size;
1054 if ((bs != 1) && !sending) {
1056 for (ctr = 0; ctr < n_recs; ctr++) {
1057 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1059 * If tmpret == 0 then this means publicly invalid so we can
1060 * short circuit things here. Otherwise we must respect constant
1065 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1069 if (pad && !sending) {
1070 for (ctr = 0; ctr < n_recs; ctr++) {
1071 recs[ctr].length -= pad;
1078 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1080 unsigned char *mac_sec, *seq;
1081 const EVP_MD_CTX *hash;
1082 unsigned char *p, rec_char;
1088 mac_sec = &(ssl->s3->write_mac_secret[0]);
1089 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1090 hash = ssl->write_hash;
1092 mac_sec = &(ssl->s3->read_mac_secret[0]);
1093 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1094 hash = ssl->read_hash;
1097 t = EVP_MD_CTX_size(hash);
1101 npad = (48 / md_size) * md_size;
1104 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1105 ssl3_cbc_record_digest_supported(hash)) {
1107 * This is a CBC-encrypted record. We must avoid leaking any
1108 * timing-side channel information about how many blocks of data we
1109 * are hashing because that gives an attacker a timing-oracle.
1113 * npad is, at most, 48 bytes and that's with MD5:
1114 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1116 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1117 * goes up 4, but npad goes down by 8, resulting in a smaller
1120 unsigned char header[75];
1122 memcpy(header + j, mac_sec, md_size);
1124 memcpy(header + j, ssl3_pad_1, npad);
1126 memcpy(header + j, seq, 8);
1128 header[j++] = rec->type;
1129 header[j++] = (unsigned char)(rec->length >> 8);
1130 header[j++] = (unsigned char)(rec->length & 0xff);
1132 /* Final param == is SSLv3 */
1133 if (ssl3_cbc_digest_record(hash,
1136 rec->length + md_size, rec->orig_len,
1137 mac_sec, md_size, 1) <= 0)
1140 unsigned int md_size_u;
1141 /* Chop the digest off the end :-) */
1142 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1147 rec_char = rec->type;
1149 s2n(rec->length, p);
1150 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1151 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1152 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1153 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1154 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1155 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1156 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1157 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1158 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1159 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1160 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1161 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1162 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1163 EVP_MD_CTX_reset(md_ctx);
1167 EVP_MD_CTX_free(md_ctx);
1170 ssl3_record_sequence_update(seq);
1174 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1180 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1181 unsigned char header[13];
1182 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1183 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1187 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1188 hash = ssl->write_hash;
1190 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1191 hash = ssl->read_hash;
1194 t = EVP_MD_CTX_size(hash);
1195 if (!ossl_assert(t >= 0))
1199 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1203 hmac = EVP_MD_CTX_new();
1204 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1209 if (SSL_IS_DTLS(ssl)) {
1210 unsigned char dtlsseq[8], *p = dtlsseq;
1212 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1213 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1214 memcpy(p, &seq[2], 6);
1216 memcpy(header, dtlsseq, 8);
1218 memcpy(header, seq, 8);
1220 header[8] = rec->type;
1221 header[9] = (unsigned char)(ssl->version >> 8);
1222 header[10] = (unsigned char)(ssl->version);
1223 header[11] = (unsigned char)(rec->length >> 8);
1224 header[12] = (unsigned char)(rec->length & 0xff);
1226 if (!sending && !SSL_READ_ETM(ssl) &&
1227 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1228 ssl3_cbc_record_digest_supported(mac_ctx)) {
1230 * This is a CBC-encrypted record. We must avoid leaking any
1231 * timing-side channel information about how many blocks of data we
1232 * are hashing because that gives an attacker a timing-oracle.
1234 /* Final param == not SSLv3 */
1235 if (ssl3_cbc_digest_record(mac_ctx,
1238 rec->length + md_size, rec->orig_len,
1239 ssl->s3->read_mac_secret,
1240 ssl->s3->read_mac_secret_size, 0) <= 0) {
1241 EVP_MD_CTX_free(hmac);
1245 /* TODO(size_t): Convert these calls */
1246 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1247 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1248 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1249 EVP_MD_CTX_free(hmac);
1254 EVP_MD_CTX_free(hmac);
1257 fprintf(stderr, "seq=");
1260 for (z = 0; z < 8; z++)
1261 fprintf(stderr, "%02X ", seq[z]);
1262 fprintf(stderr, "\n");
1264 fprintf(stderr, "rec=");
1267 for (z = 0; z < rec->length; z++)
1268 fprintf(stderr, "%02X ", rec->data[z]);
1269 fprintf(stderr, "\n");
1273 if (!SSL_IS_DTLS(ssl)) {
1274 for (i = 7; i >= 0; i--) {
1283 for (z = 0; z < md_size; z++)
1284 fprintf(stderr, "%02X ", md[z]);
1285 fprintf(stderr, "\n");
1292 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1293 * record in |rec| by updating |rec->length| in constant time.
1295 * block_size: the block size of the cipher used to encrypt the record.
1297 * 0: (in non-constant time) if the record is publicly invalid.
1298 * 1: if the padding was valid
1301 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1302 size_t block_size, size_t mac_size)
1304 size_t padding_length;
1306 const size_t overhead = 1 /* padding length byte */ + mac_size;
1309 * These lengths are all public so we can test them in non-constant time.
1311 if (overhead > rec->length)
1314 padding_length = rec->data[rec->length - 1];
1315 good = constant_time_ge_s(rec->length, padding_length + overhead);
1316 /* SSLv3 requires that the padding is minimal. */
1317 good &= constant_time_ge_s(block_size, padding_length + 1);
1318 rec->length -= good & (padding_length + 1);
1319 return constant_time_select_int_s(good, 1, -1);
1323 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1324 * record in |rec| in constant time and returns 1 if the padding is valid and
1325 * -1 otherwise. It also removes any explicit IV from the start of the record
1326 * without leaking any timing about whether there was enough space after the
1327 * padding was removed.
1329 * block_size: the block size of the cipher used to encrypt the record.
1331 * 0: (in non-constant time) if the record is publicly invalid.
1332 * 1: if the padding was valid
1335 int tls1_cbc_remove_padding(const SSL *s,
1337 size_t block_size, size_t mac_size)
1340 size_t padding_length, to_check, i;
1341 const size_t overhead = 1 /* padding length byte */ + mac_size;
1342 /* Check if version requires explicit IV */
1343 if (SSL_USE_EXPLICIT_IV(s)) {
1345 * These lengths are all public so we can test them in non-constant
1348 if (overhead + block_size > rec->length)
1350 /* We can now safely skip explicit IV */
1351 rec->data += block_size;
1352 rec->input += block_size;
1353 rec->length -= block_size;
1354 rec->orig_len -= block_size;
1355 } else if (overhead > rec->length)
1358 padding_length = rec->data[rec->length - 1];
1360 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1361 EVP_CIPH_FLAG_AEAD_CIPHER) {
1362 /* padding is already verified */
1363 rec->length -= padding_length + 1;
1367 good = constant_time_ge_s(rec->length, overhead + padding_length);
1369 * The padding consists of a length byte at the end of the record and
1370 * then that many bytes of padding, all with the same value as the length
1371 * byte. Thus, with the length byte included, there are i+1 bytes of
1372 * padding. We can't check just |padding_length+1| bytes because that
1373 * leaks decrypted information. Therefore we always have to check the
1374 * maximum amount of padding possible. (Again, the length of the record
1375 * is public information so we can use it.)
1377 to_check = 256; /* maximum amount of padding, inc length byte. */
1378 if (to_check > rec->length)
1379 to_check = rec->length;
1381 for (i = 0; i < to_check; i++) {
1382 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1383 unsigned char b = rec->data[rec->length - 1 - i];
1385 * The final |padding_length+1| bytes should all have the value
1386 * |padding_length|. Therefore the XOR should be zero.
1388 good &= ~(mask & (padding_length ^ b));
1392 * If any of the final |padding_length+1| bytes had the wrong value, one
1393 * or more of the lower eight bits of |good| will be cleared.
1395 good = constant_time_eq_s(0xff, good & 0xff);
1396 rec->length -= good & (padding_length + 1);
1398 return constant_time_select_int_s(good, 1, -1);
1402 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1403 * constant time (independent of the concrete value of rec->length, which may
1404 * vary within a 256-byte window).
1406 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1410 * rec->orig_len >= md_size
1411 * md_size <= EVP_MAX_MD_SIZE
1413 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1414 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1415 * a single or pair of cache-lines, then the variable memory accesses don't
1416 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1417 * not multi-core and are not considered vulnerable to cache-timing attacks.
1419 #define CBC_MAC_ROTATE_IN_PLACE
1421 int ssl3_cbc_copy_mac(unsigned char *out,
1422 const SSL3_RECORD *rec, size_t md_size)
1424 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1425 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1426 unsigned char *rotated_mac;
1428 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1432 * mac_end is the index of |rec->data| just after the end of the MAC.
1434 size_t mac_end = rec->length;
1435 size_t mac_start = mac_end - md_size;
1438 * scan_start contains the number of bytes that we can ignore because the
1439 * MAC's position can only vary by 255 bytes.
1441 size_t scan_start = 0;
1443 size_t rotate_offset;
1445 if (!ossl_assert(rec->orig_len >= md_size
1446 && md_size <= EVP_MAX_MD_SIZE))
1449 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1450 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1453 /* This information is public so it's safe to branch based on it. */
1454 if (rec->orig_len > md_size + 255 + 1)
1455 scan_start = rec->orig_len - (md_size + 255 + 1);
1459 memset(rotated_mac, 0, md_size);
1460 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1461 size_t mac_started = constant_time_eq_s(i, mac_start);
1462 size_t mac_ended = constant_time_lt_s(i, mac_end);
1463 unsigned char b = rec->data[i];
1465 in_mac |= mac_started;
1466 in_mac &= mac_ended;
1467 rotate_offset |= j & mac_started;
1468 rotated_mac[j++] |= b & in_mac;
1469 j &= constant_time_lt_s(j, md_size);
1472 /* Now rotate the MAC */
1473 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1475 for (i = 0; i < md_size; i++) {
1476 /* in case cache-line is 32 bytes, touch second line */
1477 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1478 out[j++] = rotated_mac[rotate_offset++];
1479 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1482 memset(out, 0, md_size);
1483 rotate_offset = md_size - rotate_offset;
1484 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1485 for (i = 0; i < md_size; i++) {
1486 for (j = 0; j < md_size; j++)
1487 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1489 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1496 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1504 unsigned char md[EVP_MAX_MD_SIZE];
1506 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1510 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1511 * and we have that many bytes in s->packet
1513 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1516 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1517 * at rr->length bytes, which need to be copied into rr->data by either
1518 * the decryption or by the decompression When the data is 'copied' into
1519 * the rr->data buffer, rr->input will be pointed at the new buffer
1523 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1524 * bytes of encrypted compressed stuff.
1527 /* check is not needed I believe */
1528 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1529 al = SSL_AD_RECORD_OVERFLOW;
1530 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1534 /* decrypt in place in 'rr->input' */
1535 rr->data = rr->input;
1536 rr->orig_len = rr->length;
1538 if (SSL_READ_ETM(s) && s->read_hash) {
1540 mac_size = EVP_MD_CTX_size(s->read_hash);
1541 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1542 al = SSL_AD_INTERNAL_ERROR;
1543 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1546 if (rr->orig_len < mac_size) {
1547 al = SSL_AD_DECODE_ERROR;
1548 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1551 rr->length -= mac_size;
1552 mac = rr->data + rr->length;
1553 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1554 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1555 al = SSL_AD_BAD_RECORD_MAC;
1556 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1557 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1562 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1565 * 0: (in non-constant time) if the record is publically invalid.
1566 * 1: if the padding is valid
1567 * -1: if the padding is invalid
1570 /* For DTLS we simply ignore bad packets. */
1572 RECORD_LAYER_reset_packet_length(&s->rlayer);
1576 printf("dec %ld\n", rr->length);
1579 for (z = 0; z < rr->length; z++)
1580 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1585 /* r->length is now the compressed data plus mac */
1586 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1587 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1588 /* s->read_hash != NULL => mac_size != -1 */
1589 unsigned char *mac = NULL;
1590 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1592 /* TODO(size_t): Convert this to do size_t properly */
1593 imac_size = EVP_MD_CTX_size(s->read_hash);
1594 if (imac_size < 0) {
1595 al = SSL_AD_INTERNAL_ERROR;
1596 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1599 mac_size = (size_t)imac_size;
1600 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1601 al = SSL_AD_INTERNAL_ERROR;
1602 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1607 * orig_len is the length of the record before any padding was
1608 * removed. This is public information, as is the MAC in use,
1609 * therefore we can safely process the record in a different amount
1610 * of time if it's too short to possibly contain a MAC.
1612 if (rr->orig_len < mac_size ||
1613 /* CBC records must have a padding length byte too. */
1614 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1615 rr->orig_len < mac_size + 1)) {
1616 al = SSL_AD_DECODE_ERROR;
1617 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1621 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1623 * We update the length so that the TLS header bytes can be
1624 * constructed correctly but we need to extract the MAC in
1625 * constant time from within the record, without leaking the
1626 * contents of the padding bytes.
1629 if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
1630 al = SSL_AD_INTERNAL_ERROR;
1631 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1634 rr->length -= mac_size;
1637 * In this case there's no padding, so |rec->orig_len| equals
1638 * |rec->length| and we checked that there's enough bytes for
1641 rr->length -= mac_size;
1642 mac = &rr->data[rr->length];
1645 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1646 if (i == 0 || mac == NULL
1647 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1649 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1654 /* decryption failed, silently discard message */
1656 RECORD_LAYER_reset_packet_length(&s->rlayer);
1660 /* r->length is now just compressed */
1661 if (s->expand != NULL) {
1662 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1663 al = SSL_AD_RECORD_OVERFLOW;
1664 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1665 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1668 if (!ssl3_do_uncompress(s, rr)) {
1669 al = SSL_AD_DECOMPRESSION_FAILURE;
1670 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1675 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1676 al = SSL_AD_RECORD_OVERFLOW;
1677 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1683 * So at this point the following is true
1684 * ssl->s3->rrec.type is the type of record
1685 * ssl->s3->rrec.length == number of bytes in record
1686 * ssl->s3->rrec.off == offset to first valid byte
1687 * ssl->s3->rrec.data == where to take bytes from, increment
1691 /* we have pulled in a full packet so zero things */
1692 RECORD_LAYER_reset_packet_length(&s->rlayer);
1694 /* Mark receipt of record. */
1695 dtls1_record_bitmap_update(s, bitmap);
1700 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1706 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1708 #define dtls1_get_processed_record(s) \
1709 dtls1_retrieve_buffered_record((s), \
1710 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1713 * Call this to get a new input record.
1714 * It will return <= 0 if more data is needed, normally due to an error
1715 * or non-blocking IO.
1716 * When it finishes, one packet has been decoded and can be found in
1717 * ssl->s3->rrec.type - is the type of record
1718 * ssl->s3->rrec.data, - data
1719 * ssl->s3->rrec.length, - number of bytes
1721 /* used only by dtls1_read_bytes */
1722 int dtls1_get_record(SSL *s)
1724 int ssl_major, ssl_minor;
1728 unsigned char *p = NULL;
1729 unsigned short version;
1730 DTLS1_BITMAP *bitmap;
1731 unsigned int is_next_epoch;
1733 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1737 * The epoch may have changed. If so, process all the pending records.
1738 * This is a non-blocking operation.
1740 if (!dtls1_process_buffered_records(s))
1743 /* if we're renegotiating, then there may be buffered records */
1744 if (dtls1_get_processed_record(s))
1747 /* get something from the wire */
1749 /* check if we have the header */
1750 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1751 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1752 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1753 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1754 /* read timeout is handled by dtls1_read_bytes */
1756 return rret; /* error or non-blocking */
1758 /* this packet contained a partial record, dump it */
1759 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1760 DTLS1_RT_HEADER_LENGTH) {
1761 RECORD_LAYER_reset_packet_length(&s->rlayer);
1765 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1767 p = RECORD_LAYER_get_packet(&s->rlayer);
1769 if (s->msg_callback)
1770 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1771 s, s->msg_callback_arg);
1773 /* Pull apart the header into the DTLS1_RECORD */
1777 version = (ssl_major << 8) | ssl_minor;
1779 /* sequence number is 64 bits, with top 2 bytes = epoch */
1782 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1787 /* Lets check version */
1788 if (!s->first_packet) {
1789 if (version != s->version) {
1790 /* unexpected version, silently discard */
1792 RECORD_LAYER_reset_packet_length(&s->rlayer);
1797 if ((version & 0xff00) != (s->version & 0xff00)) {
1798 /* wrong version, silently discard record */
1800 RECORD_LAYER_reset_packet_length(&s->rlayer);
1804 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1805 /* record too long, silently discard it */
1807 RECORD_LAYER_reset_packet_length(&s->rlayer);
1811 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1814 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1817 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1818 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1820 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1821 /* this packet contained a partial record, dump it */
1822 if (rret <= 0 || n != more) {
1824 RECORD_LAYER_reset_packet_length(&s->rlayer);
1829 * now n == rr->length, and s->packet_length ==
1830 * DTLS1_RT_HEADER_LENGTH + rr->length
1833 /* set state for later operations */
1834 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1836 /* match epochs. NULL means the packet is dropped on the floor */
1837 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1838 if (bitmap == NULL) {
1840 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1841 goto again; /* get another record */
1843 #ifndef OPENSSL_NO_SCTP
1844 /* Only do replay check if no SCTP bio */
1845 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1847 /* Check whether this is a repeat, or aged record. */
1849 * TODO: Does it make sense to have replay protection in epoch 0 where
1850 * we have no integrity negotiated yet?
1852 if (!dtls1_record_replay_check(s, bitmap)) {
1854 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1855 goto again; /* get another record */
1857 #ifndef OPENSSL_NO_SCTP
1861 /* just read a 0 length packet */
1862 if (rr->length == 0)
1866 * If this record is from the next epoch (either HM or ALERT), and a
1867 * handshake is currently in progress, buffer it since it cannot be
1868 * processed at this time.
1870 if (is_next_epoch) {
1871 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1872 if (dtls1_buffer_record
1873 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1878 RECORD_LAYER_reset_packet_length(&s->rlayer);
1882 if (!dtls1_process_record(s, bitmap)) {
1884 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1885 goto again; /* get another record */