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
11 #include "../ssl_locl.h"
12 #include "internal/constant_time_locl.h"
13 #include <openssl/rand.h>
14 #include "record_locl.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 assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE);
440 if (imac_size < 0 || imac_size > EVP_MAX_MD_SIZE) {
441 al = SSL_AD_INTERNAL_ERROR;
442 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_LIB_EVP);
445 mac_size = (size_t)imac_size;
446 for (j = 0; j < num_recs; j++) {
449 if (thisrr->length < mac_size) {
450 al = SSL_AD_DECODE_ERROR;
451 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
454 thisrr->length -= mac_size;
455 mac = thisrr->data + thisrr->length;
456 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
457 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
458 al = SSL_AD_BAD_RECORD_MAC;
459 SSLerr(SSL_F_SSL3_GET_RECORD,
460 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
466 first_rec_len = rr[0].length;
468 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
472 * 0: (in non-constant time) if the record is publicly invalid.
473 * 1: if the padding is valid
474 * -1: if the padding is invalid
477 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
479 * Valid early_data that we cannot decrypt might fail here as
480 * publicly invalid. We treat it like an empty record.
485 if (!early_data_count_ok(s, thisrr->length,
486 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
491 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
492 RECORD_LAYER_reset_read_sequence(&s->rlayer);
495 al = SSL_AD_DECRYPTION_FAILED;
496 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
500 printf("dec %"OSSLzu"\n", rr[0].length);
503 for (z = 0; z < rr[0].length; z++)
504 printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
509 /* r->length is now the compressed data plus mac */
510 if ((sess != NULL) &&
511 (s->enc_read_ctx != NULL) &&
512 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
513 /* s->read_hash != NULL => mac_size != -1 */
514 unsigned char *mac = NULL;
515 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
517 mac_size = EVP_MD_CTX_size(s->read_hash);
518 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
519 al = SSL_AD_INTERNAL_ERROR;
520 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
524 for (j = 0; j < num_recs; j++) {
527 * orig_len is the length of the record before any padding was
528 * removed. This is public information, as is the MAC in use,
529 * therefore we can safely process the record in a different amount
530 * of time if it's too short to possibly contain a MAC.
532 if (thisrr->orig_len < mac_size ||
533 /* CBC records must have a padding length byte too. */
534 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
535 thisrr->orig_len < mac_size + 1)) {
536 al = SSL_AD_DECODE_ERROR;
537 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
541 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
543 * We update the length so that the TLS header bytes can be
544 * constructed correctly but we need to extract the MAC in
545 * constant time from within the record, without leaking the
546 * contents of the padding bytes.
549 if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
550 al = SSL_AD_INTERNAL_ERROR;
551 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
554 thisrr->length -= mac_size;
557 * In this case there's no padding, so |rec->orig_len| equals
558 * |rec->length| and we checked that there's enough bytes for
561 thisrr->length -= mac_size;
562 mac = &thisrr->data[thisrr->length];
565 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
566 if (i == 0 || mac == NULL
567 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
569 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
575 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
577 * We assume this is unreadable early_data - we treat it like an
582 * The record length may have been modified by the mac check above
583 * so we use the previously saved value
585 if (!early_data_count_ok(s, first_rec_len,
586 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
592 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
593 RECORD_LAYER_reset_read_sequence(&s->rlayer);
597 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
598 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
599 * failure is directly visible from the ciphertext anyway, we should
600 * not reveal which kind of error occurred -- this might become
601 * visible to an attacker (e.g. via a logfile)
603 al = SSL_AD_BAD_RECORD_MAC;
604 SSLerr(SSL_F_SSL3_GET_RECORD,
605 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
609 for (j = 0; j < num_recs; j++) {
612 /* thisrr->length is now just compressed */
613 if (s->expand != NULL) {
614 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
615 al = SSL_AD_RECORD_OVERFLOW;
616 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
619 if (!ssl3_do_uncompress(s, thisrr)) {
620 al = SSL_AD_DECOMPRESSION_FAILURE;
621 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
626 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
629 if (thisrr->length == 0
630 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
631 al = SSL_AD_UNEXPECTED_MESSAGE;
632 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
636 /* Strip trailing padding */
637 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
641 thisrr->length = end;
642 thisrr->type = thisrr->data[end];
643 if (thisrr->type != SSL3_RT_APPLICATION_DATA
644 && thisrr->type != SSL3_RT_ALERT
645 && thisrr->type != SSL3_RT_HANDSHAKE) {
646 al = SSL_AD_UNEXPECTED_MESSAGE;
647 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
651 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
652 &thisrr->data[end], 1, s, s->msg_callback_arg);
656 * TLSv1.3 alert and handshake records are required to be non-zero in
660 && (thisrr->type == SSL3_RT_HANDSHAKE
661 || thisrr->type == SSL3_RT_ALERT)
662 && thisrr->length == 0) {
663 al = SSL_AD_UNEXPECTED_MESSAGE;
664 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_LENGTH);
668 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
669 al = SSL_AD_RECORD_OVERFLOW;
670 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
676 * So at this point the following is true
677 * thisrr->type is the type of record
678 * thisrr->length == number of bytes in record
679 * thisrr->off == offset to first valid byte
680 * thisrr->data == where to take bytes from, increment after use :-).
683 /* just read a 0 length packet */
684 if (thisrr->length == 0) {
685 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
686 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
687 > MAX_EMPTY_RECORDS) {
688 al = SSL_AD_UNEXPECTED_MESSAGE;
689 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
693 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
697 if (s->early_data_state == SSL_EARLY_DATA_READING) {
699 if (thisrr->type == SSL3_RT_APPLICATION_DATA
700 && !early_data_count_ok(s, thisrr->length, 0, &al))
704 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
708 ssl3_send_alert(s, SSL3_AL_FATAL, al);
713 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
715 #ifndef OPENSSL_NO_COMP
718 if (rr->comp == NULL) {
719 rr->comp = (unsigned char *)
720 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
722 if (rr->comp == NULL)
725 /* TODO(size_t): Convert this call */
726 i = COMP_expand_block(ssl->expand, rr->comp,
727 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
737 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
739 #ifndef OPENSSL_NO_COMP
742 /* TODO(size_t): Convert this call */
743 i = COMP_compress_block(ssl->compress, wr->data,
744 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
745 wr->input, (int)wr->length);
751 wr->input = wr->data;
757 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
760 * 0: (in non-constant time) if the record is publically invalid (i.e. too
762 * 1: if the record's padding is valid / the encryption was successful.
763 * -1: if the record's padding is invalid or, if sending, an internal error
766 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
771 size_t bs, mac_size = 0;
773 const EVP_CIPHER *enc;
777 * We shouldn't ever be called with more than one record in the SSLv3 case
782 ds = s->enc_write_ctx;
783 if (s->enc_write_ctx == NULL)
786 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
788 ds = s->enc_read_ctx;
789 if (s->enc_read_ctx == NULL)
792 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
795 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
796 memmove(rec->data, rec->input, rec->length);
797 rec->input = rec->data;
800 /* TODO(size_t): Convert this call */
801 bs = EVP_CIPHER_CTX_block_size(ds);
805 if ((bs != 1) && sending) {
808 /* we need to add 'i-1' padding bytes */
811 * the last of these zero bytes will be overwritten with the
814 memset(&rec->input[rec->length], 0, i);
816 rec->input[l - 1] = (unsigned char)(i - 1);
820 if (l == 0 || l % bs != 0)
822 /* otherwise, rec->length >= bs */
825 /* TODO(size_t): Convert this call */
826 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
829 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
830 /* TODO(size_t): convert me */
831 imac_size = EVP_MD_CTX_size(s->read_hash);
834 mac_size = (size_t)imac_size;
836 if ((bs != 1) && !sending)
837 return ssl3_cbc_remove_padding(rec, bs, mac_size);
842 #define MAX_PADDING 256
844 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
847 * 0: (in non-constant time) if the record is publically invalid (i.e. too
849 * 1: if the record's padding is valid / the encryption was successful.
850 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
851 * an internal error occurred.
853 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
856 size_t reclen[SSL_MAX_PIPELINES];
857 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
858 int i, pad = 0, ret, tmpr;
859 size_t bs, mac_size = 0, ctr, padnum, loop;
860 unsigned char padval;
862 const EVP_CIPHER *enc;
868 if (EVP_MD_CTX_md(s->write_hash)) {
869 int n = EVP_MD_CTX_size(s->write_hash);
870 if (!ossl_assert(n >= 0)) {
871 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
875 ds = s->enc_write_ctx;
876 if (s->enc_write_ctx == NULL)
880 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
881 /* For TLSv1.1 and later explicit IV */
882 if (SSL_USE_EXPLICIT_IV(s)
883 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
884 ivlen = EVP_CIPHER_iv_length(enc);
888 for (ctr = 0; ctr < n_recs; ctr++) {
889 if (recs[ctr].data != recs[ctr].input) {
891 * we can't write into the input stream: Can this ever
894 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
896 } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
897 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
904 if (EVP_MD_CTX_md(s->read_hash)) {
905 int n = EVP_MD_CTX_size(s->read_hash);
906 if (!ossl_assert(n >= 0)) {
907 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
911 ds = s->enc_read_ctx;
912 if (s->enc_read_ctx == NULL)
915 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
918 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
919 for (ctr = 0; ctr < n_recs; ctr++) {
920 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
921 recs[ctr].input = recs[ctr].data;
925 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
928 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
929 & EVP_CIPH_FLAG_PIPELINE)) {
931 * We shouldn't have been called with pipeline data if the
932 * cipher doesn't support pipelining
934 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
938 for (ctr = 0; ctr < n_recs; ctr++) {
939 reclen[ctr] = recs[ctr].length;
941 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
942 & EVP_CIPH_FLAG_AEAD_CIPHER) {
945 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
946 : RECORD_LAYER_get_read_sequence(&s->rlayer);
948 if (SSL_IS_DTLS(s)) {
949 /* DTLS does not support pipelining */
950 unsigned char dtlsseq[9], *p = dtlsseq;
952 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
953 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
954 memcpy(p, &seq[2], 6);
955 memcpy(buf[ctr], dtlsseq, 8);
957 memcpy(buf[ctr], seq, 8);
958 for (i = 7; i >= 0; i--) { /* increment */
965 buf[ctr][8] = recs[ctr].type;
966 buf[ctr][9] = (unsigned char)(s->version >> 8);
967 buf[ctr][10] = (unsigned char)(s->version);
968 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
969 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
970 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
971 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
977 recs[ctr].length += pad;
980 } else if ((bs != 1) && sending) {
981 padnum = bs - (reclen[ctr] % bs);
983 /* Add weird padding of upto 256 bytes */
985 if (padnum > MAX_PADDING)
987 /* we need to add 'padnum' padding bytes of value padval */
988 padval = (unsigned char)(padnum - 1);
989 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
990 recs[ctr].input[loop] = padval;
991 reclen[ctr] += padnum;
992 recs[ctr].length += padnum;
996 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
1001 unsigned char *data[SSL_MAX_PIPELINES];
1003 /* Set the output buffers */
1004 for (ctr = 0; ctr < n_recs; ctr++) {
1005 data[ctr] = recs[ctr].data;
1007 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
1008 (int)n_recs, data) <= 0) {
1009 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1011 /* Set the input buffers */
1012 for (ctr = 0; ctr < n_recs; ctr++) {
1013 data[ctr] = recs[ctr].input;
1015 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
1016 (int)n_recs, data) <= 0
1017 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1018 (int)n_recs, reclen) <= 0) {
1019 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1024 /* TODO(size_t): Convert this call */
1025 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1026 (unsigned int)reclen[0]);
1027 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1028 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1031 return -1; /* AEAD can fail to verify MAC */
1033 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1034 for (ctr = 0; ctr < n_recs; ctr++) {
1035 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1036 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1037 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1039 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1040 for (ctr = 0; ctr < n_recs; ctr++) {
1041 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1042 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1043 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1049 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1050 imac_size = EVP_MD_CTX_size(s->read_hash);
1053 mac_size = (size_t)imac_size;
1055 if ((bs != 1) && !sending) {
1057 for (ctr = 0; ctr < n_recs; ctr++) {
1058 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1060 * If tmpret == 0 then this means publicly invalid so we can
1061 * short circuit things here. Otherwise we must respect constant
1066 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1070 if (pad && !sending) {
1071 for (ctr = 0; ctr < n_recs; ctr++) {
1072 recs[ctr].length -= pad;
1079 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1081 unsigned char *mac_sec, *seq;
1082 const EVP_MD_CTX *hash;
1083 unsigned char *p, rec_char;
1089 mac_sec = &(ssl->s3->write_mac_secret[0]);
1090 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1091 hash = ssl->write_hash;
1093 mac_sec = &(ssl->s3->read_mac_secret[0]);
1094 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1095 hash = ssl->read_hash;
1098 t = EVP_MD_CTX_size(hash);
1102 npad = (48 / md_size) * md_size;
1105 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1106 ssl3_cbc_record_digest_supported(hash)) {
1108 * This is a CBC-encrypted record. We must avoid leaking any
1109 * timing-side channel information about how many blocks of data we
1110 * are hashing because that gives an attacker a timing-oracle.
1114 * npad is, at most, 48 bytes and that's with MD5:
1115 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1117 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1118 * goes up 4, but npad goes down by 8, resulting in a smaller
1121 unsigned char header[75];
1123 memcpy(header + j, mac_sec, md_size);
1125 memcpy(header + j, ssl3_pad_1, npad);
1127 memcpy(header + j, seq, 8);
1129 header[j++] = rec->type;
1130 header[j++] = (unsigned char)(rec->length >> 8);
1131 header[j++] = (unsigned char)(rec->length & 0xff);
1133 /* Final param == is SSLv3 */
1134 if (ssl3_cbc_digest_record(hash,
1137 rec->length + md_size, rec->orig_len,
1138 mac_sec, md_size, 1) <= 0)
1141 unsigned int md_size_u;
1142 /* Chop the digest off the end :-) */
1143 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1148 rec_char = rec->type;
1150 s2n(rec->length, p);
1151 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1152 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1153 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1154 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1155 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1156 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1157 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1158 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1159 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1160 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1161 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1162 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1163 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1164 EVP_MD_CTX_reset(md_ctx);
1168 EVP_MD_CTX_free(md_ctx);
1171 ssl3_record_sequence_update(seq);
1175 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1181 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1182 unsigned char header[13];
1183 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1184 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1188 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1189 hash = ssl->write_hash;
1191 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1192 hash = ssl->read_hash;
1195 t = EVP_MD_CTX_size(hash);
1196 if (!ossl_assert(t >= 0))
1200 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1204 hmac = EVP_MD_CTX_new();
1205 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1210 if (SSL_IS_DTLS(ssl)) {
1211 unsigned char dtlsseq[8], *p = dtlsseq;
1213 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1214 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1215 memcpy(p, &seq[2], 6);
1217 memcpy(header, dtlsseq, 8);
1219 memcpy(header, seq, 8);
1221 header[8] = rec->type;
1222 header[9] = (unsigned char)(ssl->version >> 8);
1223 header[10] = (unsigned char)(ssl->version);
1224 header[11] = (unsigned char)(rec->length >> 8);
1225 header[12] = (unsigned char)(rec->length & 0xff);
1227 if (!sending && !SSL_READ_ETM(ssl) &&
1228 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1229 ssl3_cbc_record_digest_supported(mac_ctx)) {
1231 * This is a CBC-encrypted record. We must avoid leaking any
1232 * timing-side channel information about how many blocks of data we
1233 * are hashing because that gives an attacker a timing-oracle.
1235 /* Final param == not SSLv3 */
1236 if (ssl3_cbc_digest_record(mac_ctx,
1239 rec->length + md_size, rec->orig_len,
1240 ssl->s3->read_mac_secret,
1241 ssl->s3->read_mac_secret_size, 0) <= 0) {
1242 EVP_MD_CTX_free(hmac);
1246 /* TODO(size_t): Convert these calls */
1247 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1248 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1249 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1250 EVP_MD_CTX_free(hmac);
1255 EVP_MD_CTX_free(hmac);
1258 fprintf(stderr, "seq=");
1261 for (z = 0; z < 8; z++)
1262 fprintf(stderr, "%02X ", seq[z]);
1263 fprintf(stderr, "\n");
1265 fprintf(stderr, "rec=");
1268 for (z = 0; z < rec->length; z++)
1269 fprintf(stderr, "%02X ", rec->data[z]);
1270 fprintf(stderr, "\n");
1274 if (!SSL_IS_DTLS(ssl)) {
1275 for (i = 7; i >= 0; i--) {
1284 for (z = 0; z < md_size; z++)
1285 fprintf(stderr, "%02X ", md[z]);
1286 fprintf(stderr, "\n");
1293 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1294 * record in |rec| by updating |rec->length| in constant time.
1296 * block_size: the block size of the cipher used to encrypt the record.
1298 * 0: (in non-constant time) if the record is publicly invalid.
1299 * 1: if the padding was valid
1302 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1303 size_t block_size, size_t mac_size)
1305 size_t padding_length;
1307 const size_t overhead = 1 /* padding length byte */ + mac_size;
1310 * These lengths are all public so we can test them in non-constant time.
1312 if (overhead > rec->length)
1315 padding_length = rec->data[rec->length - 1];
1316 good = constant_time_ge_s(rec->length, padding_length + overhead);
1317 /* SSLv3 requires that the padding is minimal. */
1318 good &= constant_time_ge_s(block_size, padding_length + 1);
1319 rec->length -= good & (padding_length + 1);
1320 return constant_time_select_int_s(good, 1, -1);
1324 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1325 * record in |rec| in constant time and returns 1 if the padding is valid and
1326 * -1 otherwise. It also removes any explicit IV from the start of the record
1327 * without leaking any timing about whether there was enough space after the
1328 * padding was removed.
1330 * block_size: the block size of the cipher used to encrypt the record.
1332 * 0: (in non-constant time) if the record is publicly invalid.
1333 * 1: if the padding was valid
1336 int tls1_cbc_remove_padding(const SSL *s,
1338 size_t block_size, size_t mac_size)
1341 size_t padding_length, to_check, i;
1342 const size_t overhead = 1 /* padding length byte */ + mac_size;
1343 /* Check if version requires explicit IV */
1344 if (SSL_USE_EXPLICIT_IV(s)) {
1346 * These lengths are all public so we can test them in non-constant
1349 if (overhead + block_size > rec->length)
1351 /* We can now safely skip explicit IV */
1352 rec->data += block_size;
1353 rec->input += block_size;
1354 rec->length -= block_size;
1355 rec->orig_len -= block_size;
1356 } else if (overhead > rec->length)
1359 padding_length = rec->data[rec->length - 1];
1361 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1362 EVP_CIPH_FLAG_AEAD_CIPHER) {
1363 /* padding is already verified */
1364 rec->length -= padding_length + 1;
1368 good = constant_time_ge_s(rec->length, overhead + padding_length);
1370 * The padding consists of a length byte at the end of the record and
1371 * then that many bytes of padding, all with the same value as the length
1372 * byte. Thus, with the length byte included, there are i+1 bytes of
1373 * padding. We can't check just |padding_length+1| bytes because that
1374 * leaks decrypted information. Therefore we always have to check the
1375 * maximum amount of padding possible. (Again, the length of the record
1376 * is public information so we can use it.)
1378 to_check = 256; /* maximum amount of padding, inc length byte. */
1379 if (to_check > rec->length)
1380 to_check = rec->length;
1382 for (i = 0; i < to_check; i++) {
1383 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1384 unsigned char b = rec->data[rec->length - 1 - i];
1386 * The final |padding_length+1| bytes should all have the value
1387 * |padding_length|. Therefore the XOR should be zero.
1389 good &= ~(mask & (padding_length ^ b));
1393 * If any of the final |padding_length+1| bytes had the wrong value, one
1394 * or more of the lower eight bits of |good| will be cleared.
1396 good = constant_time_eq_s(0xff, good & 0xff);
1397 rec->length -= good & (padding_length + 1);
1399 return constant_time_select_int_s(good, 1, -1);
1403 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1404 * constant time (independent of the concrete value of rec->length, which may
1405 * vary within a 256-byte window).
1407 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1411 * rec->orig_len >= md_size
1412 * md_size <= EVP_MAX_MD_SIZE
1414 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1415 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1416 * a single or pair of cache-lines, then the variable memory accesses don't
1417 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1418 * not multi-core and are not considered vulnerable to cache-timing attacks.
1420 #define CBC_MAC_ROTATE_IN_PLACE
1422 int ssl3_cbc_copy_mac(unsigned char *out,
1423 const SSL3_RECORD *rec, size_t md_size)
1425 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1426 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1427 unsigned char *rotated_mac;
1429 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1433 * mac_end is the index of |rec->data| just after the end of the MAC.
1435 size_t mac_end = rec->length;
1436 size_t mac_start = mac_end - md_size;
1439 * scan_start contains the number of bytes that we can ignore because the
1440 * MAC's position can only vary by 255 bytes.
1442 size_t scan_start = 0;
1444 size_t rotate_offset;
1446 if (!ossl_assert(rec->orig_len >= md_size
1447 && md_size <= EVP_MAX_MD_SIZE))
1450 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1451 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1454 /* This information is public so it's safe to branch based on it. */
1455 if (rec->orig_len > md_size + 255 + 1)
1456 scan_start = rec->orig_len - (md_size + 255 + 1);
1460 memset(rotated_mac, 0, md_size);
1461 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1462 size_t mac_started = constant_time_eq_s(i, mac_start);
1463 size_t mac_ended = constant_time_lt_s(i, mac_end);
1464 unsigned char b = rec->data[i];
1466 in_mac |= mac_started;
1467 in_mac &= mac_ended;
1468 rotate_offset |= j & mac_started;
1469 rotated_mac[j++] |= b & in_mac;
1470 j &= constant_time_lt_s(j, md_size);
1473 /* Now rotate the MAC */
1474 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1476 for (i = 0; i < md_size; i++) {
1477 /* in case cache-line is 32 bytes, touch second line */
1478 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1479 out[j++] = rotated_mac[rotate_offset++];
1480 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1483 memset(out, 0, md_size);
1484 rotate_offset = md_size - rotate_offset;
1485 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1486 for (i = 0; i < md_size; i++) {
1487 for (j = 0; j < md_size; j++)
1488 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1490 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1497 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1505 unsigned char md[EVP_MAX_MD_SIZE];
1507 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1511 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1512 * and we have that many bytes in s->packet
1514 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1517 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1518 * at rr->length bytes, which need to be copied into rr->data by either
1519 * the decryption or by the decompression When the data is 'copied' into
1520 * the rr->data buffer, rr->input will be pointed at the new buffer
1524 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1525 * bytes of encrypted compressed stuff.
1528 /* check is not needed I believe */
1529 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1530 al = SSL_AD_RECORD_OVERFLOW;
1531 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1535 /* decrypt in place in 'rr->input' */
1536 rr->data = rr->input;
1537 rr->orig_len = rr->length;
1539 if (SSL_READ_ETM(s) && s->read_hash) {
1541 mac_size = EVP_MD_CTX_size(s->read_hash);
1542 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1543 al = SSL_AD_INTERNAL_ERROR;
1544 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1547 if (rr->orig_len < mac_size) {
1548 al = SSL_AD_DECODE_ERROR;
1549 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1552 rr->length -= mac_size;
1553 mac = rr->data + rr->length;
1554 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1555 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1556 al = SSL_AD_BAD_RECORD_MAC;
1557 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1558 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1563 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1566 * 0: (in non-constant time) if the record is publically invalid.
1567 * 1: if the padding is valid
1568 * -1: if the padding is invalid
1571 /* For DTLS we simply ignore bad packets. */
1573 RECORD_LAYER_reset_packet_length(&s->rlayer);
1577 printf("dec %ld\n", rr->length);
1580 for (z = 0; z < rr->length; z++)
1581 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1586 /* r->length is now the compressed data plus mac */
1587 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1588 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1589 /* s->read_hash != NULL => mac_size != -1 */
1590 unsigned char *mac = NULL;
1591 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1593 /* TODO(size_t): Convert this to do size_t properly */
1594 imac_size = EVP_MD_CTX_size(s->read_hash);
1595 if (imac_size < 0) {
1596 al = SSL_AD_INTERNAL_ERROR;
1597 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1600 mac_size = (size_t)imac_size;
1601 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1602 al = SSL_AD_INTERNAL_ERROR;
1603 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1608 * orig_len is the length of the record before any padding was
1609 * removed. This is public information, as is the MAC in use,
1610 * therefore we can safely process the record in a different amount
1611 * of time if it's too short to possibly contain a MAC.
1613 if (rr->orig_len < mac_size ||
1614 /* CBC records must have a padding length byte too. */
1615 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1616 rr->orig_len < mac_size + 1)) {
1617 al = SSL_AD_DECODE_ERROR;
1618 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1622 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1624 * We update the length so that the TLS header bytes can be
1625 * constructed correctly but we need to extract the MAC in
1626 * constant time from within the record, without leaking the
1627 * contents of the padding bytes.
1630 if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
1631 al = SSL_AD_INTERNAL_ERROR;
1632 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_R_INTERNAL_ERROR);
1635 rr->length -= mac_size;
1638 * In this case there's no padding, so |rec->orig_len| equals
1639 * |rec->length| and we checked that there's enough bytes for
1642 rr->length -= mac_size;
1643 mac = &rr->data[rr->length];
1646 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1647 if (i == 0 || mac == NULL
1648 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1650 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1655 /* decryption failed, silently discard message */
1657 RECORD_LAYER_reset_packet_length(&s->rlayer);
1661 /* r->length is now just compressed */
1662 if (s->expand != NULL) {
1663 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1664 al = SSL_AD_RECORD_OVERFLOW;
1665 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1666 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1669 if (!ssl3_do_uncompress(s, rr)) {
1670 al = SSL_AD_DECOMPRESSION_FAILURE;
1671 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1676 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1677 al = SSL_AD_RECORD_OVERFLOW;
1678 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1684 * So at this point the following is true
1685 * ssl->s3->rrec.type is the type of record
1686 * ssl->s3->rrec.length == number of bytes in record
1687 * ssl->s3->rrec.off == offset to first valid byte
1688 * ssl->s3->rrec.data == where to take bytes from, increment
1692 /* we have pulled in a full packet so zero things */
1693 RECORD_LAYER_reset_packet_length(&s->rlayer);
1695 /* Mark receipt of record. */
1696 dtls1_record_bitmap_update(s, bitmap);
1701 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1707 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1709 #define dtls1_get_processed_record(s) \
1710 dtls1_retrieve_buffered_record((s), \
1711 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1714 * Call this to get a new input record.
1715 * It will return <= 0 if more data is needed, normally due to an error
1716 * or non-blocking IO.
1717 * When it finishes, one packet has been decoded and can be found in
1718 * ssl->s3->rrec.type - is the type of record
1719 * ssl->s3->rrec.data, - data
1720 * ssl->s3->rrec.length, - number of bytes
1722 /* used only by dtls1_read_bytes */
1723 int dtls1_get_record(SSL *s)
1725 int ssl_major, ssl_minor;
1729 unsigned char *p = NULL;
1730 unsigned short version;
1731 DTLS1_BITMAP *bitmap;
1732 unsigned int is_next_epoch;
1734 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1738 * The epoch may have changed. If so, process all the pending records.
1739 * This is a non-blocking operation.
1741 if (!dtls1_process_buffered_records(s))
1744 /* if we're renegotiating, then there may be buffered records */
1745 if (dtls1_get_processed_record(s))
1748 /* get something from the wire */
1750 /* check if we have the header */
1751 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1752 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1753 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1754 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1755 /* read timeout is handled by dtls1_read_bytes */
1757 return rret; /* error or non-blocking */
1759 /* this packet contained a partial record, dump it */
1760 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1761 DTLS1_RT_HEADER_LENGTH) {
1762 RECORD_LAYER_reset_packet_length(&s->rlayer);
1766 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1768 p = RECORD_LAYER_get_packet(&s->rlayer);
1770 if (s->msg_callback)
1771 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1772 s, s->msg_callback_arg);
1774 /* Pull apart the header into the DTLS1_RECORD */
1778 version = (ssl_major << 8) | ssl_minor;
1780 /* sequence number is 64 bits, with top 2 bytes = epoch */
1783 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1788 /* Lets check version */
1789 if (!s->first_packet) {
1790 if (version != s->version) {
1791 /* unexpected version, silently discard */
1793 RECORD_LAYER_reset_packet_length(&s->rlayer);
1798 if ((version & 0xff00) != (s->version & 0xff00)) {
1799 /* wrong version, silently discard record */
1801 RECORD_LAYER_reset_packet_length(&s->rlayer);
1805 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1806 /* record too long, silently discard it */
1808 RECORD_LAYER_reset_packet_length(&s->rlayer);
1812 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1815 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1818 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1819 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1821 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1822 /* this packet contained a partial record, dump it */
1823 if (rret <= 0 || n != more) {
1825 RECORD_LAYER_reset_packet_length(&s->rlayer);
1830 * now n == rr->length, and s->packet_length ==
1831 * DTLS1_RT_HEADER_LENGTH + rr->length
1834 /* set state for later operations */
1835 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1837 /* match epochs. NULL means the packet is dropped on the floor */
1838 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1839 if (bitmap == NULL) {
1841 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1842 goto again; /* get another record */
1844 #ifndef OPENSSL_NO_SCTP
1845 /* Only do replay check if no SCTP bio */
1846 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1848 /* Check whether this is a repeat, or aged record. */
1850 * TODO: Does it make sense to have replay protection in epoch 0 where
1851 * we have no integrity negotiated yet?
1853 if (!dtls1_record_replay_check(s, bitmap)) {
1855 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1856 goto again; /* get another record */
1858 #ifndef OPENSSL_NO_SCTP
1862 /* just read a 0 length packet */
1863 if (rr->length == 0)
1867 * If this record is from the next epoch (either HM or ALERT), and a
1868 * handshake is currently in progress, buffer it since it cannot be
1869 * processed at this time.
1871 if (is_next_epoch) {
1872 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1873 if (dtls1_buffer_record
1874 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1879 RECORD_LAYER_reset_packet_length(&s->rlayer);
1883 if (!dtls1_process_record(s, bitmap)) {
1885 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1886 goto again; /* get another record */