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_INTERNAL_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_HANDSHAKE_FAILURE;
245 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
249 /* SSLv3+ style record */
251 * TODO(TLS1.3): This callback only provides the "outer" record
252 * type to the callback. Somehow we need to pass the "inner"
256 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
257 s->msg_callback_arg);
259 /* Pull apart the header into the SSL3_RECORD */
260 if (!PACKET_get_1(&pkt, &type)
261 || !PACKET_get_net_2(&pkt, &version)
262 || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
263 al = SSL_AD_INTERNAL_ERROR;
264 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
268 thisrr->rec_version = version;
270 /* Lets check version. In TLSv1.3 we ignore this field */
271 if (!s->first_packet && !SSL_IS_TLS13(s)
272 && version != (unsigned int)s->version) {
273 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
274 if ((s->version & 0xFF00) == (version & 0xFF00)
275 && !s->enc_write_ctx && !s->write_hash) {
276 if (thisrr->type == SSL3_RT_ALERT) {
278 * The record is using an incorrect version number,
279 * but what we've got appears to be an alert. We
280 * haven't read the body yet to check whether its a
281 * fatal or not - but chances are it is. We probably
282 * shouldn't send a fatal alert back. We'll just
288 * Send back error using their minor version number :-)
290 s->version = (unsigned short)version;
292 al = SSL_AD_PROTOCOL_VERSION;
296 if ((version >> 8) != SSL3_VERSION_MAJOR) {
297 if (RECORD_LAYER_is_first_record(&s->rlayer)) {
298 /* Go back to start of packet, look at the five bytes
300 p = RECORD_LAYER_get_packet(&s->rlayer);
301 if (strncmp((char *)p, "GET ", 4) == 0 ||
302 strncmp((char *)p, "POST ", 5) == 0 ||
303 strncmp((char *)p, "HEAD ", 5) == 0 ||
304 strncmp((char *)p, "PUT ", 4) == 0) {
305 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_HTTP_REQUEST);
307 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
308 SSLerr(SSL_F_SSL3_GET_RECORD,
309 SSL_R_HTTPS_PROXY_REQUEST);
313 /* Doesn't look like TLS - don't send an alert */
314 SSLerr(SSL_F_SSL3_GET_RECORD,
315 SSL_R_WRONG_VERSION_NUMBER);
318 SSLerr(SSL_F_SSL3_GET_RECORD,
319 SSL_R_WRONG_VERSION_NUMBER);
320 al = SSL_AD_PROTOCOL_VERSION;
325 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL
326 && thisrr->type != SSL3_RT_APPLICATION_DATA) {
327 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
328 al = SSL_AD_UNEXPECTED_MESSAGE;
333 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
334 al = SSL_AD_RECORD_OVERFLOW;
335 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
340 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
343 if (SSL_IS_TLS13(s)) {
344 if (thisrr->length > SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH) {
345 al = SSL_AD_RECORD_OVERFLOW;
346 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
350 size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
352 #ifndef OPENSSL_NO_COMP
354 * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
355 * does not include the compression overhead anyway.
357 if (s->expand == NULL)
358 len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
361 if (thisrr->length > len) {
362 al = SSL_AD_RECORD_OVERFLOW;
363 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
369 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
370 * Calculate how much more data we need to read for the rest of the
373 if (thisrr->rec_version == SSL2_VERSION) {
374 more = thisrr->length + SSL2_RT_HEADER_LENGTH
375 - SSL3_RT_HEADER_LENGTH;
377 more = thisrr->length;
380 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
382 rret = ssl3_read_n(s, more, more, 1, 0, &n);
384 return rret; /* error or non-blocking io */
387 /* set state for later operations */
388 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
391 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH
392 * + thisrr->length, or s->packet_length == SSL2_RT_HEADER_LENGTH
393 * + thisrr->length and we have that many bytes in s->packet
395 if (thisrr->rec_version == SSL2_VERSION) {
397 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
400 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
404 * ok, we can now read from 's->packet' data into 'thisrr' thisrr->input
405 * points at thisrr->length bytes, which need to be copied into
406 * thisrr->data by either the decryption or by the decompression When
407 * the data is 'copied' into the thisrr->data buffer, thisrr->input will
408 * be pointed at the new buffer
412 * We now have - encrypted [ MAC [ compressed [ plain ] ] ]
413 * thisrr->length bytes of encrypted compressed stuff.
416 /* decrypt in place in 'thisrr->input' */
417 thisrr->data = thisrr->input;
418 thisrr->orig_len = thisrr->length;
420 /* Mark this record as not read by upper layers yet */
425 /* we have pulled in a full packet so zero things */
426 RECORD_LAYER_reset_packet_length(&s->rlayer);
427 RECORD_LAYER_clear_first_record(&s->rlayer);
428 } while (num_recs < max_recs
429 && thisrr->type == SSL3_RT_APPLICATION_DATA
430 && SSL_USE_EXPLICIT_IV(s)
431 && s->enc_read_ctx != NULL
432 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
433 & EVP_CIPH_FLAG_PIPELINE)
434 && ssl3_record_app_data_waiting(s));
437 * If in encrypt-then-mac mode calculate mac from encrypted record. All
438 * the details below are public so no timing details can leak.
440 if (SSL_READ_ETM(s) && s->read_hash) {
442 /* TODO(size_t): convert this to do size_t properly */
443 imac_size = EVP_MD_CTX_size(s->read_hash);
444 assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE);
445 if (imac_size < 0 || imac_size > EVP_MAX_MD_SIZE) {
446 al = SSL_AD_INTERNAL_ERROR;
447 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_LIB_EVP);
450 mac_size = (size_t)imac_size;
451 for (j = 0; j < num_recs; j++) {
454 if (thisrr->length < mac_size) {
455 al = SSL_AD_DECODE_ERROR;
456 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
459 thisrr->length -= mac_size;
460 mac = thisrr->data + thisrr->length;
461 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
462 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
463 al = SSL_AD_BAD_RECORD_MAC;
464 SSLerr(SSL_F_SSL3_GET_RECORD,
465 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
471 first_rec_len = rr[0].length;
473 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
477 * 0: (in non-constant time) if the record is publicly invalid.
478 * 1: if the padding is valid
479 * -1: if the padding is invalid
482 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
484 * Valid early_data that we cannot decrypt might fail here as
485 * publicly invalid. We treat it like an empty record.
490 if (!early_data_count_ok(s, thisrr->length,
491 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
496 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
497 RECORD_LAYER_reset_read_sequence(&s->rlayer);
500 al = SSL_AD_DECRYPTION_FAILED;
501 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
505 printf("dec %"OSSLzu"\n", rr[0].length);
508 for (z = 0; z < rr[0].length; z++)
509 printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
514 /* r->length is now the compressed data plus mac */
515 if ((sess != NULL) &&
516 (s->enc_read_ctx != NULL) &&
517 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
518 /* s->read_hash != NULL => mac_size != -1 */
519 unsigned char *mac = NULL;
520 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
522 mac_size = EVP_MD_CTX_size(s->read_hash);
523 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
525 for (j = 0; j < num_recs; j++) {
528 * orig_len is the length of the record before any padding was
529 * removed. This is public information, as is the MAC in use,
530 * therefore we can safely process the record in a different amount
531 * of time if it's too short to possibly contain a MAC.
533 if (thisrr->orig_len < mac_size ||
534 /* CBC records must have a padding length byte too. */
535 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
536 thisrr->orig_len < mac_size + 1)) {
537 al = SSL_AD_DECODE_ERROR;
538 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
542 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
544 * We update the length so that the TLS header bytes can be
545 * constructed correctly but we need to extract the MAC in
546 * constant time from within the record, without leaking the
547 * contents of the padding bytes.
550 ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size);
551 thisrr->length -= mac_size;
554 * In this case there's no padding, so |rec->orig_len| equals
555 * |rec->length| and we checked that there's enough bytes for
558 thisrr->length -= mac_size;
559 mac = &thisrr->data[thisrr->length];
562 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
563 if (i == 0 || mac == NULL
564 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
566 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
572 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
574 * We assume this is unreadable early_data - we treat it like an
579 * The record length may have been modified by the mac check above
580 * so we use the previously saved value
582 if (!early_data_count_ok(s, first_rec_len,
583 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
589 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
590 RECORD_LAYER_reset_read_sequence(&s->rlayer);
594 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
595 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
596 * failure is directly visible from the ciphertext anyway, we should
597 * not reveal which kind of error occurred -- this might become
598 * visible to an attacker (e.g. via a logfile)
600 al = SSL_AD_BAD_RECORD_MAC;
601 SSLerr(SSL_F_SSL3_GET_RECORD,
602 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
606 for (j = 0; j < num_recs; j++) {
609 /* thisrr->length is now just compressed */
610 if (s->expand != NULL) {
611 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
612 al = SSL_AD_RECORD_OVERFLOW;
613 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
616 if (!ssl3_do_uncompress(s, thisrr)) {
617 al = SSL_AD_DECOMPRESSION_FAILURE;
618 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
623 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
626 if (thisrr->length == 0) {
627 al = SSL_AD_UNEXPECTED_MESSAGE;
628 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
632 /* Strip trailing padding */
633 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
637 thisrr->length = end;
638 thisrr->type = thisrr->data[end];
639 if (thisrr->type != SSL3_RT_APPLICATION_DATA
640 && thisrr->type != SSL3_RT_ALERT
641 && thisrr->type != SSL3_RT_HANDSHAKE) {
642 al = SSL_AD_UNEXPECTED_MESSAGE;
643 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
648 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
649 al = SSL_AD_RECORD_OVERFLOW;
650 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
656 * So at this point the following is true
657 * thisrr->type is the type of record
658 * thisrr->length == number of bytes in record
659 * thisrr->off == offset to first valid byte
660 * thisrr->data == where to take bytes from, increment after use :-).
663 /* just read a 0 length packet */
664 if (thisrr->length == 0) {
665 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
666 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
667 > MAX_EMPTY_RECORDS) {
668 al = SSL_AD_UNEXPECTED_MESSAGE;
669 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
673 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
677 if (s->early_data_state == SSL_EARLY_DATA_READING) {
679 if (thisrr->type == SSL3_RT_APPLICATION_DATA
680 && !early_data_count_ok(s, thisrr->length, 0, &al))
684 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
688 ssl3_send_alert(s, SSL3_AL_FATAL, al);
693 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
695 #ifndef OPENSSL_NO_COMP
698 if (rr->comp == NULL) {
699 rr->comp = (unsigned char *)
700 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
702 if (rr->comp == NULL)
705 /* TODO(size_t): Convert this call */
706 i = COMP_expand_block(ssl->expand, rr->comp,
707 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
717 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
719 #ifndef OPENSSL_NO_COMP
722 /* TODO(size_t): Convert this call */
723 i = COMP_compress_block(ssl->compress, wr->data,
724 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
725 wr->input, (int)wr->length);
731 wr->input = wr->data;
737 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
740 * 0: (in non-constant time) if the record is publically invalid (i.e. too
742 * 1: if the record's padding is valid / the encryption was successful.
743 * -1: if the record's padding is invalid or, if sending, an internal error
746 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int send)
751 size_t bs, mac_size = 0;
753 const EVP_CIPHER *enc;
757 * We shouldn't ever be called with more than one record in the SSLv3 case
762 ds = s->enc_write_ctx;
763 if (s->enc_write_ctx == NULL)
766 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
768 ds = s->enc_read_ctx;
769 if (s->enc_read_ctx == NULL)
772 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
775 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
776 memmove(rec->data, rec->input, rec->length);
777 rec->input = rec->data;
780 /* TODO(size_t): Convert this call */
781 bs = EVP_CIPHER_CTX_block_size(ds);
785 if ((bs != 1) && send) {
788 /* we need to add 'i-1' padding bytes */
791 * the last of these zero bytes will be overwritten with the
794 memset(&rec->input[rec->length], 0, i);
796 rec->input[l - 1] = (unsigned char)(i - 1);
800 if (l == 0 || l % bs != 0)
802 /* otherwise, rec->length >= bs */
805 /* TODO(size_t): Convert this call */
806 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
809 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
810 /* TODO(size_t): convert me */
811 imac_size = EVP_MD_CTX_size(s->read_hash);
814 mac_size = (size_t)imac_size;
816 if ((bs != 1) && !send)
817 return ssl3_cbc_remove_padding(rec, bs, mac_size);
822 #define MAX_PADDING 256
824 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
827 * 0: (in non-constant time) if the record is publically invalid (i.e. too
829 * 1: if the record's padding is valid / the encryption was successful.
830 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
831 * an internal error occurred.
833 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
836 size_t reclen[SSL_MAX_PIPELINES];
837 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
838 int i, pad = 0, ret, tmpr;
839 size_t bs, mac_size = 0, ctr, padnum, loop;
840 unsigned char padval;
842 const EVP_CIPHER *enc;
848 if (EVP_MD_CTX_md(s->write_hash)) {
849 int n = EVP_MD_CTX_size(s->write_hash);
850 OPENSSL_assert(n >= 0);
852 ds = s->enc_write_ctx;
853 if (s->enc_write_ctx == NULL)
857 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
858 /* For TLSv1.1 and later explicit IV */
859 if (SSL_USE_EXPLICIT_IV(s)
860 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
861 ivlen = EVP_CIPHER_iv_length(enc);
865 for (ctr = 0; ctr < n_recs; ctr++) {
866 if (recs[ctr].data != recs[ctr].input) {
868 * we can't write into the input stream: Can this ever
871 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
873 } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
874 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
881 if (EVP_MD_CTX_md(s->read_hash)) {
882 int n = EVP_MD_CTX_size(s->read_hash);
883 OPENSSL_assert(n >= 0);
885 ds = s->enc_read_ctx;
886 if (s->enc_read_ctx == NULL)
889 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
892 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
893 for (ctr = 0; ctr < n_recs; ctr++) {
894 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
895 recs[ctr].input = recs[ctr].data;
899 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
902 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
903 & EVP_CIPH_FLAG_PIPELINE)) {
905 * We shouldn't have been called with pipeline data if the
906 * cipher doesn't support pipelining
908 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
912 for (ctr = 0; ctr < n_recs; ctr++) {
913 reclen[ctr] = recs[ctr].length;
915 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
916 & EVP_CIPH_FLAG_AEAD_CIPHER) {
919 seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer)
920 : RECORD_LAYER_get_read_sequence(&s->rlayer);
922 if (SSL_IS_DTLS(s)) {
923 /* DTLS does not support pipelining */
924 unsigned char dtlsseq[9], *p = dtlsseq;
926 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
927 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
928 memcpy(p, &seq[2], 6);
929 memcpy(buf[ctr], dtlsseq, 8);
931 memcpy(buf[ctr], seq, 8);
932 for (i = 7; i >= 0; i--) { /* increment */
939 buf[ctr][8] = recs[ctr].type;
940 buf[ctr][9] = (unsigned char)(s->version >> 8);
941 buf[ctr][10] = (unsigned char)(s->version);
942 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
943 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
944 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
945 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
951 recs[ctr].length += pad;
954 } else if ((bs != 1) && send) {
955 padnum = bs - (reclen[ctr] % bs);
957 /* Add weird padding of upto 256 bytes */
959 if (padnum > MAX_PADDING)
961 /* we need to add 'padnum' padding bytes of value padval */
962 padval = (unsigned char)(padnum - 1);
963 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
964 recs[ctr].input[loop] = padval;
965 reclen[ctr] += padnum;
966 recs[ctr].length += padnum;
970 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
975 unsigned char *data[SSL_MAX_PIPELINES];
977 /* Set the output buffers */
978 for (ctr = 0; ctr < n_recs; ctr++) {
979 data[ctr] = recs[ctr].data;
981 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
982 (int)n_recs, data) <= 0) {
983 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
985 /* Set the input buffers */
986 for (ctr = 0; ctr < n_recs; ctr++) {
987 data[ctr] = recs[ctr].input;
989 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
990 (int)n_recs, data) <= 0
991 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
992 (int)n_recs, reclen) <= 0) {
993 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
998 /* TODO(size_t): Convert this call */
999 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1000 (unsigned int)reclen[0]);
1001 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1002 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1005 return -1; /* AEAD can fail to verify MAC */
1007 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1008 for (ctr = 0; ctr < n_recs; ctr++) {
1009 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1010 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1011 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1013 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1014 for (ctr = 0; ctr < n_recs; ctr++) {
1015 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1016 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1017 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1023 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1024 imac_size = EVP_MD_CTX_size(s->read_hash);
1027 mac_size = (size_t)imac_size;
1029 if ((bs != 1) && !send) {
1031 for (ctr = 0; ctr < n_recs; ctr++) {
1032 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1034 * If tmpret == 0 then this means publicly invalid so we can
1035 * short circuit things here. Otherwise we must respect constant
1040 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1045 for (ctr = 0; ctr < n_recs; ctr++) {
1046 recs[ctr].length -= pad;
1053 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send)
1055 unsigned char *mac_sec, *seq;
1056 const EVP_MD_CTX *hash;
1057 unsigned char *p, rec_char;
1063 mac_sec = &(ssl->s3->write_mac_secret[0]);
1064 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1065 hash = ssl->write_hash;
1067 mac_sec = &(ssl->s3->read_mac_secret[0]);
1068 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1069 hash = ssl->read_hash;
1072 t = EVP_MD_CTX_size(hash);
1076 npad = (48 / md_size) * md_size;
1079 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1080 ssl3_cbc_record_digest_supported(hash)) {
1082 * This is a CBC-encrypted record. We must avoid leaking any
1083 * timing-side channel information about how many blocks of data we
1084 * are hashing because that gives an attacker a timing-oracle.
1088 * npad is, at most, 48 bytes and that's with MD5:
1089 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1091 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1092 * goes up 4, but npad goes down by 8, resulting in a smaller
1095 unsigned char header[75];
1097 memcpy(header + j, mac_sec, md_size);
1099 memcpy(header + j, ssl3_pad_1, npad);
1101 memcpy(header + j, seq, 8);
1103 header[j++] = rec->type;
1104 header[j++] = (unsigned char)(rec->length >> 8);
1105 header[j++] = (unsigned char)(rec->length & 0xff);
1107 /* Final param == is SSLv3 */
1108 if (ssl3_cbc_digest_record(hash,
1111 rec->length + md_size, rec->orig_len,
1112 mac_sec, md_size, 1) <= 0)
1115 unsigned int md_size_u;
1116 /* Chop the digest off the end :-) */
1117 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1122 rec_char = rec->type;
1124 s2n(rec->length, p);
1125 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1126 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1127 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1128 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1129 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1130 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1131 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1132 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1133 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1134 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1135 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1136 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1137 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1138 EVP_MD_CTX_reset(md_ctx);
1142 EVP_MD_CTX_free(md_ctx);
1145 ssl3_record_sequence_update(seq);
1149 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send)
1155 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1156 unsigned char header[13];
1157 int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1158 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1162 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1163 hash = ssl->write_hash;
1165 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1166 hash = ssl->read_hash;
1169 t = EVP_MD_CTX_size(hash);
1170 OPENSSL_assert(t >= 0);
1173 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1177 hmac = EVP_MD_CTX_new();
1178 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1183 if (SSL_IS_DTLS(ssl)) {
1184 unsigned char dtlsseq[8], *p = dtlsseq;
1186 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1187 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1188 memcpy(p, &seq[2], 6);
1190 memcpy(header, dtlsseq, 8);
1192 memcpy(header, seq, 8);
1194 header[8] = rec->type;
1195 header[9] = (unsigned char)(ssl->version >> 8);
1196 header[10] = (unsigned char)(ssl->version);
1197 header[11] = (unsigned char)(rec->length >> 8);
1198 header[12] = (unsigned char)(rec->length & 0xff);
1200 if (!send && !SSL_READ_ETM(ssl) &&
1201 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1202 ssl3_cbc_record_digest_supported(mac_ctx)) {
1204 * This is a CBC-encrypted record. We must avoid leaking any
1205 * timing-side channel information about how many blocks of data we
1206 * are hashing because that gives an attacker a timing-oracle.
1208 /* Final param == not SSLv3 */
1209 if (ssl3_cbc_digest_record(mac_ctx,
1212 rec->length + md_size, rec->orig_len,
1213 ssl->s3->read_mac_secret,
1214 ssl->s3->read_mac_secret_size, 0) <= 0) {
1215 EVP_MD_CTX_free(hmac);
1219 /* TODO(size_t): Convert these calls */
1220 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1221 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1222 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1223 EVP_MD_CTX_free(hmac);
1228 EVP_MD_CTX_free(hmac);
1231 fprintf(stderr, "seq=");
1234 for (z = 0; z < 8; z++)
1235 fprintf(stderr, "%02X ", seq[z]);
1236 fprintf(stderr, "\n");
1238 fprintf(stderr, "rec=");
1241 for (z = 0; z < rec->length; z++)
1242 fprintf(stderr, "%02X ", rec->data[z]);
1243 fprintf(stderr, "\n");
1247 if (!SSL_IS_DTLS(ssl)) {
1248 for (i = 7; i >= 0; i--) {
1257 for (z = 0; z < md_size; z++)
1258 fprintf(stderr, "%02X ", md[z]);
1259 fprintf(stderr, "\n");
1266 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1267 * record in |rec| by updating |rec->length| in constant time.
1269 * block_size: the block size of the cipher used to encrypt the record.
1271 * 0: (in non-constant time) if the record is publicly invalid.
1272 * 1: if the padding was valid
1275 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1276 size_t block_size, size_t mac_size)
1278 size_t padding_length;
1280 const size_t overhead = 1 /* padding length byte */ + mac_size;
1283 * These lengths are all public so we can test them in non-constant time.
1285 if (overhead > rec->length)
1288 padding_length = rec->data[rec->length - 1];
1289 good = constant_time_ge_s(rec->length, padding_length + overhead);
1290 /* SSLv3 requires that the padding is minimal. */
1291 good &= constant_time_ge_s(block_size, padding_length + 1);
1292 rec->length -= good & (padding_length + 1);
1293 return constant_time_select_int_s(good, 1, -1);
1297 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1298 * record in |rec| in constant time and returns 1 if the padding is valid and
1299 * -1 otherwise. It also removes any explicit IV from the start of the record
1300 * without leaking any timing about whether there was enough space after the
1301 * padding was removed.
1303 * block_size: the block size of the cipher used to encrypt the record.
1305 * 0: (in non-constant time) if the record is publicly invalid.
1306 * 1: if the padding was valid
1309 int tls1_cbc_remove_padding(const SSL *s,
1311 size_t block_size, size_t mac_size)
1314 size_t padding_length, to_check, i;
1315 const size_t overhead = 1 /* padding length byte */ + mac_size;
1316 /* Check if version requires explicit IV */
1317 if (SSL_USE_EXPLICIT_IV(s)) {
1319 * These lengths are all public so we can test them in non-constant
1322 if (overhead + block_size > rec->length)
1324 /* We can now safely skip explicit IV */
1325 rec->data += block_size;
1326 rec->input += block_size;
1327 rec->length -= block_size;
1328 rec->orig_len -= block_size;
1329 } else if (overhead > rec->length)
1332 padding_length = rec->data[rec->length - 1];
1334 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1335 EVP_CIPH_FLAG_AEAD_CIPHER) {
1336 /* padding is already verified */
1337 rec->length -= padding_length + 1;
1341 good = constant_time_ge_s(rec->length, overhead + padding_length);
1343 * The padding consists of a length byte at the end of the record and
1344 * then that many bytes of padding, all with the same value as the length
1345 * byte. Thus, with the length byte included, there are i+1 bytes of
1346 * padding. We can't check just |padding_length+1| bytes because that
1347 * leaks decrypted information. Therefore we always have to check the
1348 * maximum amount of padding possible. (Again, the length of the record
1349 * is public information so we can use it.)
1351 to_check = 256; /* maximum amount of padding, inc length byte. */
1352 if (to_check > rec->length)
1353 to_check = rec->length;
1355 for (i = 0; i < to_check; i++) {
1356 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1357 unsigned char b = rec->data[rec->length - 1 - i];
1359 * The final |padding_length+1| bytes should all have the value
1360 * |padding_length|. Therefore the XOR should be zero.
1362 good &= ~(mask & (padding_length ^ b));
1366 * If any of the final |padding_length+1| bytes had the wrong value, one
1367 * or more of the lower eight bits of |good| will be cleared.
1369 good = constant_time_eq_s(0xff, good & 0xff);
1370 rec->length -= good & (padding_length + 1);
1372 return constant_time_select_int_s(good, 1, -1);
1376 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1377 * constant time (independent of the concrete value of rec->length, which may
1378 * vary within a 256-byte window).
1380 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1384 * rec->orig_len >= md_size
1385 * md_size <= EVP_MAX_MD_SIZE
1387 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1388 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1389 * a single or pair of cache-lines, then the variable memory accesses don't
1390 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1391 * not multi-core and are not considered vulnerable to cache-timing attacks.
1393 #define CBC_MAC_ROTATE_IN_PLACE
1395 void ssl3_cbc_copy_mac(unsigned char *out,
1396 const SSL3_RECORD *rec, size_t md_size)
1398 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1399 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1400 unsigned char *rotated_mac;
1402 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1406 * mac_end is the index of |rec->data| just after the end of the MAC.
1408 size_t mac_end = rec->length;
1409 size_t mac_start = mac_end - md_size;
1412 * scan_start contains the number of bytes that we can ignore because the
1413 * MAC's position can only vary by 255 bytes.
1415 size_t scan_start = 0;
1417 size_t rotate_offset;
1419 OPENSSL_assert(rec->orig_len >= md_size);
1420 OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
1422 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1423 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1426 /* This information is public so it's safe to branch based on it. */
1427 if (rec->orig_len > md_size + 255 + 1)
1428 scan_start = rec->orig_len - (md_size + 255 + 1);
1432 memset(rotated_mac, 0, md_size);
1433 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1434 size_t mac_started = constant_time_eq_s(i, mac_start);
1435 size_t mac_ended = constant_time_lt_s(i, mac_end);
1436 unsigned char b = rec->data[i];
1438 in_mac |= mac_started;
1439 in_mac &= mac_ended;
1440 rotate_offset |= j & mac_started;
1441 rotated_mac[j++] |= b & in_mac;
1442 j &= constant_time_lt_s(j, md_size);
1445 /* Now rotate the MAC */
1446 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1448 for (i = 0; i < md_size; i++) {
1449 /* in case cache-line is 32 bytes, touch second line */
1450 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1451 out[j++] = rotated_mac[rotate_offset++];
1452 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1455 memset(out, 0, md_size);
1456 rotate_offset = md_size - rotate_offset;
1457 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1458 for (i = 0; i < md_size; i++) {
1459 for (j = 0; j < md_size; j++)
1460 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1462 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1467 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1475 unsigned char md[EVP_MAX_MD_SIZE];
1477 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1481 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1482 * and we have that many bytes in s->packet
1484 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1487 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1488 * at rr->length bytes, which need to be copied into rr->data by either
1489 * the decryption or by the decompression When the data is 'copied' into
1490 * the rr->data buffer, rr->input will be pointed at the new buffer
1494 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1495 * bytes of encrypted compressed stuff.
1498 /* check is not needed I believe */
1499 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1500 al = SSL_AD_RECORD_OVERFLOW;
1501 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1505 /* decrypt in place in 'rr->input' */
1506 rr->data = rr->input;
1507 rr->orig_len = rr->length;
1509 if (SSL_READ_ETM(s) && s->read_hash) {
1511 mac_size = EVP_MD_CTX_size(s->read_hash);
1512 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1513 if (rr->orig_len < mac_size) {
1514 al = SSL_AD_DECODE_ERROR;
1515 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1518 rr->length -= mac_size;
1519 mac = rr->data + rr->length;
1520 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1521 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1522 al = SSL_AD_BAD_RECORD_MAC;
1523 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1524 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1529 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1532 * 0: (in non-constant time) if the record is publically invalid.
1533 * 1: if the padding is valid
1534 * -1: if the padding is invalid
1537 /* For DTLS we simply ignore bad packets. */
1539 RECORD_LAYER_reset_packet_length(&s->rlayer);
1543 printf("dec %ld\n", rr->length);
1546 for (z = 0; z < rr->length; z++)
1547 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1552 /* r->length is now the compressed data plus mac */
1553 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1554 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1555 /* s->read_hash != NULL => mac_size != -1 */
1556 unsigned char *mac = NULL;
1557 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1559 /* TODO(size_t): Convert this to do size_t properly */
1560 imac_size = EVP_MD_CTX_size(s->read_hash);
1561 if (imac_size < 0) {
1562 al = SSL_AD_INTERNAL_ERROR;
1563 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1566 mac_size = (size_t)imac_size;
1567 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1570 * orig_len is the length of the record before any padding was
1571 * removed. This is public information, as is the MAC in use,
1572 * therefore we can safely process the record in a different amount
1573 * of time if it's too short to possibly contain a MAC.
1575 if (rr->orig_len < mac_size ||
1576 /* CBC records must have a padding length byte too. */
1577 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1578 rr->orig_len < mac_size + 1)) {
1579 al = SSL_AD_DECODE_ERROR;
1580 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1584 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1586 * We update the length so that the TLS header bytes can be
1587 * constructed correctly but we need to extract the MAC in
1588 * constant time from within the record, without leaking the
1589 * contents of the padding bytes.
1592 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
1593 rr->length -= mac_size;
1596 * In this case there's no padding, so |rec->orig_len| equals
1597 * |rec->length| and we checked that there's enough bytes for
1600 rr->length -= mac_size;
1601 mac = &rr->data[rr->length];
1604 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1605 if (i == 0 || mac == NULL
1606 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1608 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1613 /* decryption failed, silently discard message */
1615 RECORD_LAYER_reset_packet_length(&s->rlayer);
1619 /* r->length is now just compressed */
1620 if (s->expand != NULL) {
1621 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1622 al = SSL_AD_RECORD_OVERFLOW;
1623 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1624 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1627 if (!ssl3_do_uncompress(s, rr)) {
1628 al = SSL_AD_DECOMPRESSION_FAILURE;
1629 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1634 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1635 al = SSL_AD_RECORD_OVERFLOW;
1636 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1642 * So at this point the following is true
1643 * ssl->s3->rrec.type is the type of record
1644 * ssl->s3->rrec.length == number of bytes in record
1645 * ssl->s3->rrec.off == offset to first valid byte
1646 * ssl->s3->rrec.data == where to take bytes from, increment
1650 /* we have pulled in a full packet so zero things */
1651 RECORD_LAYER_reset_packet_length(&s->rlayer);
1653 /* Mark receipt of record. */
1654 dtls1_record_bitmap_update(s, bitmap);
1659 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1665 * retrieve a buffered record that belongs to the current epoch, ie,
1668 #define dtls1_get_processed_record(s) \
1669 dtls1_retrieve_buffered_record((s), \
1670 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1673 * Call this to get a new input record.
1674 * It will return <= 0 if more data is needed, normally due to an error
1675 * or non-blocking IO.
1676 * When it finishes, one packet has been decoded and can be found in
1677 * ssl->s3->rrec.type - is the type of record
1678 * ssl->s3->rrec.data, - data
1679 * ssl->s3->rrec.length, - number of bytes
1681 /* used only by dtls1_read_bytes */
1682 int dtls1_get_record(SSL *s)
1684 int ssl_major, ssl_minor;
1688 unsigned char *p = NULL;
1689 unsigned short version;
1690 DTLS1_BITMAP *bitmap;
1691 unsigned int is_next_epoch;
1693 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1697 * The epoch may have changed. If so, process all the pending records.
1698 * This is a non-blocking operation.
1700 if (!dtls1_process_buffered_records(s))
1703 /* if we're renegotiating, then there may be buffered records */
1704 if (dtls1_get_processed_record(s))
1707 /* get something from the wire */
1709 /* check if we have the header */
1710 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1711 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1712 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1713 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1714 /* read timeout is handled by dtls1_read_bytes */
1716 return rret; /* error or non-blocking */
1718 /* this packet contained a partial record, dump it */
1719 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1720 DTLS1_RT_HEADER_LENGTH) {
1721 RECORD_LAYER_reset_packet_length(&s->rlayer);
1725 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1727 p = RECORD_LAYER_get_packet(&s->rlayer);
1729 if (s->msg_callback)
1730 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1731 s, s->msg_callback_arg);
1733 /* Pull apart the header into the DTLS1_RECORD */
1737 version = (ssl_major << 8) | ssl_minor;
1739 /* sequence number is 64 bits, with top 2 bytes = epoch */
1742 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1747 /* Lets check version */
1748 if (!s->first_packet) {
1749 if (version != s->version) {
1750 /* unexpected version, silently discard */
1752 RECORD_LAYER_reset_packet_length(&s->rlayer);
1757 if ((version & 0xff00) != (s->version & 0xff00)) {
1758 /* wrong version, silently discard record */
1760 RECORD_LAYER_reset_packet_length(&s->rlayer);
1764 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1765 /* record too long, silently discard it */
1767 RECORD_LAYER_reset_packet_length(&s->rlayer);
1771 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1774 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1777 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1778 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1780 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1781 /* this packet contained a partial record, dump it */
1782 if (rret <= 0 || n != more) {
1784 RECORD_LAYER_reset_packet_length(&s->rlayer);
1789 * now n == rr->length, and s->packet_length ==
1790 * DTLS1_RT_HEADER_LENGTH + rr->length
1793 /* set state for later operations */
1794 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1796 /* match epochs. NULL means the packet is dropped on the floor */
1797 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1798 if (bitmap == NULL) {
1800 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1801 goto again; /* get another record */
1803 #ifndef OPENSSL_NO_SCTP
1804 /* Only do replay check if no SCTP bio */
1805 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1807 /* Check whether this is a repeat, or aged record. */
1809 * TODO: Does it make sense to have replay protection in epoch 0 where
1810 * we have no integrity negotiated yet?
1812 if (!dtls1_record_replay_check(s, bitmap)) {
1814 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1815 goto again; /* get another record */
1817 #ifndef OPENSSL_NO_SCTP
1821 /* just read a 0 length packet */
1822 if (rr->length == 0)
1826 * If this record is from the next epoch (either HM or ALERT), and a
1827 * handshake is currently in progress, buffer it since it cannot be
1828 * processed at this time.
1830 if (is_next_epoch) {
1831 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1832 if (dtls1_buffer_record
1833 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1838 RECORD_LAYER_reset_packet_length(&s->rlayer);
1842 if (!dtls1_process_record(s, bitmap)) {
1844 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1845 goto again; /* get another record */