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 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_INTERNAL_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 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
520 for (j = 0; j < num_recs; j++) {
523 * orig_len is the length of the record before any padding was
524 * removed. This is public information, as is the MAC in use,
525 * therefore we can safely process the record in a different amount
526 * of time if it's too short to possibly contain a MAC.
528 if (thisrr->orig_len < mac_size ||
529 /* CBC records must have a padding length byte too. */
530 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
531 thisrr->orig_len < mac_size + 1)) {
532 al = SSL_AD_DECODE_ERROR;
533 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
537 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
539 * We update the length so that the TLS header bytes can be
540 * constructed correctly but we need to extract the MAC in
541 * constant time from within the record, without leaking the
542 * contents of the padding bytes.
545 ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size);
546 thisrr->length -= mac_size;
549 * In this case there's no padding, so |rec->orig_len| equals
550 * |rec->length| and we checked that there's enough bytes for
553 thisrr->length -= mac_size;
554 mac = &thisrr->data[thisrr->length];
557 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
558 if (i == 0 || mac == NULL
559 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
561 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
567 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
569 * We assume this is unreadable early_data - we treat it like an
574 * The record length may have been modified by the mac check above
575 * so we use the previously saved value
577 if (!early_data_count_ok(s, first_rec_len,
578 EARLY_DATA_CIPHERTEXT_OVERHEAD, &al))
584 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
585 RECORD_LAYER_reset_read_sequence(&s->rlayer);
589 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
590 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
591 * failure is directly visible from the ciphertext anyway, we should
592 * not reveal which kind of error occurred -- this might become
593 * visible to an attacker (e.g. via a logfile)
595 al = SSL_AD_BAD_RECORD_MAC;
596 SSLerr(SSL_F_SSL3_GET_RECORD,
597 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
601 for (j = 0; j < num_recs; j++) {
604 /* thisrr->length is now just compressed */
605 if (s->expand != NULL) {
606 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
607 al = SSL_AD_RECORD_OVERFLOW;
608 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
611 if (!ssl3_do_uncompress(s, thisrr)) {
612 al = SSL_AD_DECOMPRESSION_FAILURE;
613 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
618 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
621 if (thisrr->length == 0
622 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
623 al = SSL_AD_UNEXPECTED_MESSAGE;
624 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
628 /* Strip trailing padding */
629 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
633 thisrr->length = end;
634 thisrr->type = thisrr->data[end];
635 if (thisrr->type != SSL3_RT_APPLICATION_DATA
636 && thisrr->type != SSL3_RT_ALERT
637 && thisrr->type != SSL3_RT_HANDSHAKE) {
638 al = SSL_AD_UNEXPECTED_MESSAGE;
639 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
643 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
644 &thisrr->data[end], 1, s, s->msg_callback_arg);
648 && (thisrr->type == SSL3_RT_HANDSHAKE
649 || thisrr->type == SSL3_RT_ALERT)
650 && thisrr->length == 0) {
651 al = SSL_AD_UNEXPECTED_MESSAGE;
652 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_LENGTH);
656 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
657 al = SSL_AD_RECORD_OVERFLOW;
658 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
664 * So at this point the following is true
665 * thisrr->type is the type of record
666 * thisrr->length == number of bytes in record
667 * thisrr->off == offset to first valid byte
668 * thisrr->data == where to take bytes from, increment after use :-).
671 /* just read a 0 length packet */
672 if (thisrr->length == 0) {
673 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
674 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
675 > MAX_EMPTY_RECORDS) {
676 al = SSL_AD_UNEXPECTED_MESSAGE;
677 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
681 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
685 if (s->early_data_state == SSL_EARLY_DATA_READING) {
687 if (thisrr->type == SSL3_RT_APPLICATION_DATA
688 && !early_data_count_ok(s, thisrr->length, 0, &al))
692 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
696 ssl3_send_alert(s, SSL3_AL_FATAL, al);
701 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
703 #ifndef OPENSSL_NO_COMP
706 if (rr->comp == NULL) {
707 rr->comp = (unsigned char *)
708 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
710 if (rr->comp == NULL)
713 /* TODO(size_t): Convert this call */
714 i = COMP_expand_block(ssl->expand, rr->comp,
715 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
725 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
727 #ifndef OPENSSL_NO_COMP
730 /* TODO(size_t): Convert this call */
731 i = COMP_compress_block(ssl->compress, wr->data,
732 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
733 wr->input, (int)wr->length);
739 wr->input = wr->data;
745 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
748 * 0: (in non-constant time) if the record is publically invalid (i.e. too
750 * 1: if the record's padding is valid / the encryption was successful.
751 * -1: if the record's padding is invalid or, if sending, an internal error
754 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
759 size_t bs, mac_size = 0;
761 const EVP_CIPHER *enc;
765 * We shouldn't ever be called with more than one record in the SSLv3 case
770 ds = s->enc_write_ctx;
771 if (s->enc_write_ctx == NULL)
774 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
776 ds = s->enc_read_ctx;
777 if (s->enc_read_ctx == NULL)
780 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
783 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
784 memmove(rec->data, rec->input, rec->length);
785 rec->input = rec->data;
788 /* TODO(size_t): Convert this call */
789 bs = EVP_CIPHER_CTX_block_size(ds);
793 if ((bs != 1) && sending) {
796 /* we need to add 'i-1' padding bytes */
799 * the last of these zero bytes will be overwritten with the
802 memset(&rec->input[rec->length], 0, i);
804 rec->input[l - 1] = (unsigned char)(i - 1);
808 if (l == 0 || l % bs != 0)
810 /* otherwise, rec->length >= bs */
813 /* TODO(size_t): Convert this call */
814 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
817 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
818 /* TODO(size_t): convert me */
819 imac_size = EVP_MD_CTX_size(s->read_hash);
822 mac_size = (size_t)imac_size;
824 if ((bs != 1) && !sending)
825 return ssl3_cbc_remove_padding(rec, bs, mac_size);
830 #define MAX_PADDING 256
832 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
835 * 0: (in non-constant time) if the record is publically invalid (i.e. too
837 * 1: if the record's padding is valid / the encryption was successful.
838 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
839 * an internal error occurred.
841 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
844 size_t reclen[SSL_MAX_PIPELINES];
845 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
846 int i, pad = 0, ret, tmpr;
847 size_t bs, mac_size = 0, ctr, padnum, loop;
848 unsigned char padval;
850 const EVP_CIPHER *enc;
856 if (EVP_MD_CTX_md(s->write_hash)) {
857 int n = EVP_MD_CTX_size(s->write_hash);
858 OPENSSL_assert(n >= 0);
860 ds = s->enc_write_ctx;
861 if (s->enc_write_ctx == NULL)
865 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
866 /* For TLSv1.1 and later explicit IV */
867 if (SSL_USE_EXPLICIT_IV(s)
868 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
869 ivlen = EVP_CIPHER_iv_length(enc);
873 for (ctr = 0; ctr < n_recs; ctr++) {
874 if (recs[ctr].data != recs[ctr].input) {
876 * we can't write into the input stream: Can this ever
879 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
881 } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
882 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
889 if (EVP_MD_CTX_md(s->read_hash)) {
890 int n = EVP_MD_CTX_size(s->read_hash);
891 OPENSSL_assert(n >= 0);
893 ds = s->enc_read_ctx;
894 if (s->enc_read_ctx == NULL)
897 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
900 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
901 for (ctr = 0; ctr < n_recs; ctr++) {
902 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
903 recs[ctr].input = recs[ctr].data;
907 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
910 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
911 & EVP_CIPH_FLAG_PIPELINE)) {
913 * We shouldn't have been called with pipeline data if the
914 * cipher doesn't support pipelining
916 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
920 for (ctr = 0; ctr < n_recs; ctr++) {
921 reclen[ctr] = recs[ctr].length;
923 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
924 & EVP_CIPH_FLAG_AEAD_CIPHER) {
927 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
928 : RECORD_LAYER_get_read_sequence(&s->rlayer);
930 if (SSL_IS_DTLS(s)) {
931 /* DTLS does not support pipelining */
932 unsigned char dtlsseq[9], *p = dtlsseq;
934 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
935 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
936 memcpy(p, &seq[2], 6);
937 memcpy(buf[ctr], dtlsseq, 8);
939 memcpy(buf[ctr], seq, 8);
940 for (i = 7; i >= 0; i--) { /* increment */
947 buf[ctr][8] = recs[ctr].type;
948 buf[ctr][9] = (unsigned char)(s->version >> 8);
949 buf[ctr][10] = (unsigned char)(s->version);
950 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
951 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
952 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
953 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
959 recs[ctr].length += pad;
962 } else if ((bs != 1) && sending) {
963 padnum = bs - (reclen[ctr] % bs);
965 /* Add weird padding of upto 256 bytes */
967 if (padnum > MAX_PADDING)
969 /* we need to add 'padnum' padding bytes of value padval */
970 padval = (unsigned char)(padnum - 1);
971 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
972 recs[ctr].input[loop] = padval;
973 reclen[ctr] += padnum;
974 recs[ctr].length += padnum;
978 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
983 unsigned char *data[SSL_MAX_PIPELINES];
985 /* Set the output buffers */
986 for (ctr = 0; ctr < n_recs; ctr++) {
987 data[ctr] = recs[ctr].data;
989 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
990 (int)n_recs, data) <= 0) {
991 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
993 /* Set the input buffers */
994 for (ctr = 0; ctr < n_recs; ctr++) {
995 data[ctr] = recs[ctr].input;
997 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
998 (int)n_recs, data) <= 0
999 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1000 (int)n_recs, reclen) <= 0) {
1001 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
1006 /* TODO(size_t): Convert this call */
1007 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1008 (unsigned int)reclen[0]);
1009 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1010 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1013 return -1; /* AEAD can fail to verify MAC */
1015 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1016 for (ctr = 0; ctr < n_recs; ctr++) {
1017 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1018 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1019 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1021 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1022 for (ctr = 0; ctr < n_recs; ctr++) {
1023 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1024 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1025 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1031 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1032 imac_size = EVP_MD_CTX_size(s->read_hash);
1035 mac_size = (size_t)imac_size;
1037 if ((bs != 1) && !sending) {
1039 for (ctr = 0; ctr < n_recs; ctr++) {
1040 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1042 * If tmpret == 0 then this means publicly invalid so we can
1043 * short circuit things here. Otherwise we must respect constant
1048 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1052 if (pad && !sending) {
1053 for (ctr = 0; ctr < n_recs; ctr++) {
1054 recs[ctr].length -= pad;
1061 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1063 unsigned char *mac_sec, *seq;
1064 const EVP_MD_CTX *hash;
1065 unsigned char *p, rec_char;
1071 mac_sec = &(ssl->s3->write_mac_secret[0]);
1072 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1073 hash = ssl->write_hash;
1075 mac_sec = &(ssl->s3->read_mac_secret[0]);
1076 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1077 hash = ssl->read_hash;
1080 t = EVP_MD_CTX_size(hash);
1084 npad = (48 / md_size) * md_size;
1087 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1088 ssl3_cbc_record_digest_supported(hash)) {
1090 * This is a CBC-encrypted record. We must avoid leaking any
1091 * timing-side channel information about how many blocks of data we
1092 * are hashing because that gives an attacker a timing-oracle.
1096 * npad is, at most, 48 bytes and that's with MD5:
1097 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1099 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1100 * goes up 4, but npad goes down by 8, resulting in a smaller
1103 unsigned char header[75];
1105 memcpy(header + j, mac_sec, md_size);
1107 memcpy(header + j, ssl3_pad_1, npad);
1109 memcpy(header + j, seq, 8);
1111 header[j++] = rec->type;
1112 header[j++] = (unsigned char)(rec->length >> 8);
1113 header[j++] = (unsigned char)(rec->length & 0xff);
1115 /* Final param == is SSLv3 */
1116 if (ssl3_cbc_digest_record(hash,
1119 rec->length + md_size, rec->orig_len,
1120 mac_sec, md_size, 1) <= 0)
1123 unsigned int md_size_u;
1124 /* Chop the digest off the end :-) */
1125 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1130 rec_char = rec->type;
1132 s2n(rec->length, p);
1133 if (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_1, npad) <= 0
1136 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1137 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1138 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1139 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1140 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1141 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1142 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1143 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1144 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1145 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1146 EVP_MD_CTX_reset(md_ctx);
1150 EVP_MD_CTX_free(md_ctx);
1153 ssl3_record_sequence_update(seq);
1157 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1163 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1164 unsigned char header[13];
1165 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1166 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1170 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1171 hash = ssl->write_hash;
1173 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1174 hash = ssl->read_hash;
1177 t = EVP_MD_CTX_size(hash);
1178 OPENSSL_assert(t >= 0);
1181 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1185 hmac = EVP_MD_CTX_new();
1186 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1191 if (SSL_IS_DTLS(ssl)) {
1192 unsigned char dtlsseq[8], *p = dtlsseq;
1194 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1195 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1196 memcpy(p, &seq[2], 6);
1198 memcpy(header, dtlsseq, 8);
1200 memcpy(header, seq, 8);
1202 header[8] = rec->type;
1203 header[9] = (unsigned char)(ssl->version >> 8);
1204 header[10] = (unsigned char)(ssl->version);
1205 header[11] = (unsigned char)(rec->length >> 8);
1206 header[12] = (unsigned char)(rec->length & 0xff);
1208 if (!sending && !SSL_READ_ETM(ssl) &&
1209 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1210 ssl3_cbc_record_digest_supported(mac_ctx)) {
1212 * This is a CBC-encrypted record. We must avoid leaking any
1213 * timing-side channel information about how many blocks of data we
1214 * are hashing because that gives an attacker a timing-oracle.
1216 /* Final param == not SSLv3 */
1217 if (ssl3_cbc_digest_record(mac_ctx,
1220 rec->length + md_size, rec->orig_len,
1221 ssl->s3->read_mac_secret,
1222 ssl->s3->read_mac_secret_size, 0) <= 0) {
1223 EVP_MD_CTX_free(hmac);
1227 /* TODO(size_t): Convert these calls */
1228 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1229 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1230 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1231 EVP_MD_CTX_free(hmac);
1236 EVP_MD_CTX_free(hmac);
1239 fprintf(stderr, "seq=");
1242 for (z = 0; z < 8; z++)
1243 fprintf(stderr, "%02X ", seq[z]);
1244 fprintf(stderr, "\n");
1246 fprintf(stderr, "rec=");
1249 for (z = 0; z < rec->length; z++)
1250 fprintf(stderr, "%02X ", rec->data[z]);
1251 fprintf(stderr, "\n");
1255 if (!SSL_IS_DTLS(ssl)) {
1256 for (i = 7; i >= 0; i--) {
1265 for (z = 0; z < md_size; z++)
1266 fprintf(stderr, "%02X ", md[z]);
1267 fprintf(stderr, "\n");
1274 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1275 * record in |rec| by updating |rec->length| in constant time.
1277 * block_size: the block size of the cipher used to encrypt the record.
1279 * 0: (in non-constant time) if the record is publicly invalid.
1280 * 1: if the padding was valid
1283 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1284 size_t block_size, size_t mac_size)
1286 size_t padding_length;
1288 const size_t overhead = 1 /* padding length byte */ + mac_size;
1291 * These lengths are all public so we can test them in non-constant time.
1293 if (overhead > rec->length)
1296 padding_length = rec->data[rec->length - 1];
1297 good = constant_time_ge_s(rec->length, padding_length + overhead);
1298 /* SSLv3 requires that the padding is minimal. */
1299 good &= constant_time_ge_s(block_size, padding_length + 1);
1300 rec->length -= good & (padding_length + 1);
1301 return constant_time_select_int_s(good, 1, -1);
1305 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1306 * record in |rec| in constant time and returns 1 if the padding is valid and
1307 * -1 otherwise. It also removes any explicit IV from the start of the record
1308 * without leaking any timing about whether there was enough space after the
1309 * padding was removed.
1311 * block_size: the block size of the cipher used to encrypt the record.
1313 * 0: (in non-constant time) if the record is publicly invalid.
1314 * 1: if the padding was valid
1317 int tls1_cbc_remove_padding(const SSL *s,
1319 size_t block_size, size_t mac_size)
1322 size_t padding_length, to_check, i;
1323 const size_t overhead = 1 /* padding length byte */ + mac_size;
1324 /* Check if version requires explicit IV */
1325 if (SSL_USE_EXPLICIT_IV(s)) {
1327 * These lengths are all public so we can test them in non-constant
1330 if (overhead + block_size > rec->length)
1332 /* We can now safely skip explicit IV */
1333 rec->data += block_size;
1334 rec->input += block_size;
1335 rec->length -= block_size;
1336 rec->orig_len -= block_size;
1337 } else if (overhead > rec->length)
1340 padding_length = rec->data[rec->length - 1];
1342 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1343 EVP_CIPH_FLAG_AEAD_CIPHER) {
1344 /* padding is already verified */
1345 rec->length -= padding_length + 1;
1349 good = constant_time_ge_s(rec->length, overhead + padding_length);
1351 * The padding consists of a length byte at the end of the record and
1352 * then that many bytes of padding, all with the same value as the length
1353 * byte. Thus, with the length byte included, there are i+1 bytes of
1354 * padding. We can't check just |padding_length+1| bytes because that
1355 * leaks decrypted information. Therefore we always have to check the
1356 * maximum amount of padding possible. (Again, the length of the record
1357 * is public information so we can use it.)
1359 to_check = 256; /* maximum amount of padding, inc length byte. */
1360 if (to_check > rec->length)
1361 to_check = rec->length;
1363 for (i = 0; i < to_check; i++) {
1364 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1365 unsigned char b = rec->data[rec->length - 1 - i];
1367 * The final |padding_length+1| bytes should all have the value
1368 * |padding_length|. Therefore the XOR should be zero.
1370 good &= ~(mask & (padding_length ^ b));
1374 * If any of the final |padding_length+1| bytes had the wrong value, one
1375 * or more of the lower eight bits of |good| will be cleared.
1377 good = constant_time_eq_s(0xff, good & 0xff);
1378 rec->length -= good & (padding_length + 1);
1380 return constant_time_select_int_s(good, 1, -1);
1384 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1385 * constant time (independent of the concrete value of rec->length, which may
1386 * vary within a 256-byte window).
1388 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1392 * rec->orig_len >= md_size
1393 * md_size <= EVP_MAX_MD_SIZE
1395 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1396 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1397 * a single or pair of cache-lines, then the variable memory accesses don't
1398 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1399 * not multi-core and are not considered vulnerable to cache-timing attacks.
1401 #define CBC_MAC_ROTATE_IN_PLACE
1403 void ssl3_cbc_copy_mac(unsigned char *out,
1404 const SSL3_RECORD *rec, size_t md_size)
1406 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1407 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1408 unsigned char *rotated_mac;
1410 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1414 * mac_end is the index of |rec->data| just after the end of the MAC.
1416 size_t mac_end = rec->length;
1417 size_t mac_start = mac_end - md_size;
1420 * scan_start contains the number of bytes that we can ignore because the
1421 * MAC's position can only vary by 255 bytes.
1423 size_t scan_start = 0;
1425 size_t rotate_offset;
1427 OPENSSL_assert(rec->orig_len >= md_size);
1428 OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
1430 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1431 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1434 /* This information is public so it's safe to branch based on it. */
1435 if (rec->orig_len > md_size + 255 + 1)
1436 scan_start = rec->orig_len - (md_size + 255 + 1);
1440 memset(rotated_mac, 0, md_size);
1441 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1442 size_t mac_started = constant_time_eq_s(i, mac_start);
1443 size_t mac_ended = constant_time_lt_s(i, mac_end);
1444 unsigned char b = rec->data[i];
1446 in_mac |= mac_started;
1447 in_mac &= mac_ended;
1448 rotate_offset |= j & mac_started;
1449 rotated_mac[j++] |= b & in_mac;
1450 j &= constant_time_lt_s(j, md_size);
1453 /* Now rotate the MAC */
1454 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1456 for (i = 0; i < md_size; i++) {
1457 /* in case cache-line is 32 bytes, touch second line */
1458 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1459 out[j++] = rotated_mac[rotate_offset++];
1460 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1463 memset(out, 0, md_size);
1464 rotate_offset = md_size - rotate_offset;
1465 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1466 for (i = 0; i < md_size; i++) {
1467 for (j = 0; j < md_size; j++)
1468 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1470 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1475 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1483 unsigned char md[EVP_MAX_MD_SIZE];
1485 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1489 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1490 * and we have that many bytes in s->packet
1492 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1495 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1496 * at rr->length bytes, which need to be copied into rr->data by either
1497 * the decryption or by the decompression When the data is 'copied' into
1498 * the rr->data buffer, rr->input will be pointed at the new buffer
1502 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1503 * bytes of encrypted compressed stuff.
1506 /* check is not needed I believe */
1507 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1508 al = SSL_AD_RECORD_OVERFLOW;
1509 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1513 /* decrypt in place in 'rr->input' */
1514 rr->data = rr->input;
1515 rr->orig_len = rr->length;
1517 if (SSL_READ_ETM(s) && s->read_hash) {
1519 mac_size = EVP_MD_CTX_size(s->read_hash);
1520 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1521 if (rr->orig_len < mac_size) {
1522 al = SSL_AD_DECODE_ERROR;
1523 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1526 rr->length -= mac_size;
1527 mac = rr->data + rr->length;
1528 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1529 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1530 al = SSL_AD_BAD_RECORD_MAC;
1531 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1532 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1537 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1540 * 0: (in non-constant time) if the record is publically invalid.
1541 * 1: if the padding is valid
1542 * -1: if the padding is invalid
1545 /* For DTLS we simply ignore bad packets. */
1547 RECORD_LAYER_reset_packet_length(&s->rlayer);
1551 printf("dec %ld\n", rr->length);
1554 for (z = 0; z < rr->length; z++)
1555 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1560 /* r->length is now the compressed data plus mac */
1561 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1562 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1563 /* s->read_hash != NULL => mac_size != -1 */
1564 unsigned char *mac = NULL;
1565 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1567 /* TODO(size_t): Convert this to do size_t properly */
1568 imac_size = EVP_MD_CTX_size(s->read_hash);
1569 if (imac_size < 0) {
1570 al = SSL_AD_INTERNAL_ERROR;
1571 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1574 mac_size = (size_t)imac_size;
1575 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1578 * orig_len is the length of the record before any padding was
1579 * removed. This is public information, as is the MAC in use,
1580 * therefore we can safely process the record in a different amount
1581 * of time if it's too short to possibly contain a MAC.
1583 if (rr->orig_len < mac_size ||
1584 /* CBC records must have a padding length byte too. */
1585 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1586 rr->orig_len < mac_size + 1)) {
1587 al = SSL_AD_DECODE_ERROR;
1588 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1592 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1594 * We update the length so that the TLS header bytes can be
1595 * constructed correctly but we need to extract the MAC in
1596 * constant time from within the record, without leaking the
1597 * contents of the padding bytes.
1600 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
1601 rr->length -= mac_size;
1604 * In this case there's no padding, so |rec->orig_len| equals
1605 * |rec->length| and we checked that there's enough bytes for
1608 rr->length -= mac_size;
1609 mac = &rr->data[rr->length];
1612 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1613 if (i == 0 || mac == NULL
1614 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1616 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1621 /* decryption failed, silently discard message */
1623 RECORD_LAYER_reset_packet_length(&s->rlayer);
1627 /* r->length is now just compressed */
1628 if (s->expand != NULL) {
1629 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1630 al = SSL_AD_RECORD_OVERFLOW;
1631 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1632 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1635 if (!ssl3_do_uncompress(s, rr)) {
1636 al = SSL_AD_DECOMPRESSION_FAILURE;
1637 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1642 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1643 al = SSL_AD_RECORD_OVERFLOW;
1644 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1650 * So at this point the following is true
1651 * ssl->s3->rrec.type is the type of record
1652 * ssl->s3->rrec.length == number of bytes in record
1653 * ssl->s3->rrec.off == offset to first valid byte
1654 * ssl->s3->rrec.data == where to take bytes from, increment
1658 /* we have pulled in a full packet so zero things */
1659 RECORD_LAYER_reset_packet_length(&s->rlayer);
1661 /* Mark receipt of record. */
1662 dtls1_record_bitmap_update(s, bitmap);
1667 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1673 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1675 #define dtls1_get_processed_record(s) \
1676 dtls1_retrieve_buffered_record((s), \
1677 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1680 * Call this to get a new input record.
1681 * It will return <= 0 if more data is needed, normally due to an error
1682 * or non-blocking IO.
1683 * When it finishes, one packet has been decoded and can be found in
1684 * ssl->s3->rrec.type - is the type of record
1685 * ssl->s3->rrec.data, - data
1686 * ssl->s3->rrec.length, - number of bytes
1688 /* used only by dtls1_read_bytes */
1689 int dtls1_get_record(SSL *s)
1691 int ssl_major, ssl_minor;
1695 unsigned char *p = NULL;
1696 unsigned short version;
1697 DTLS1_BITMAP *bitmap;
1698 unsigned int is_next_epoch;
1700 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1704 * The epoch may have changed. If so, process all the pending records.
1705 * This is a non-blocking operation.
1707 if (!dtls1_process_buffered_records(s))
1710 /* if we're renegotiating, then there may be buffered records */
1711 if (dtls1_get_processed_record(s))
1714 /* get something from the wire */
1716 /* check if we have the header */
1717 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1718 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1719 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1720 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1721 /* read timeout is handled by dtls1_read_bytes */
1723 return rret; /* error or non-blocking */
1725 /* this packet contained a partial record, dump it */
1726 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1727 DTLS1_RT_HEADER_LENGTH) {
1728 RECORD_LAYER_reset_packet_length(&s->rlayer);
1732 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1734 p = RECORD_LAYER_get_packet(&s->rlayer);
1736 if (s->msg_callback)
1737 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1738 s, s->msg_callback_arg);
1740 /* Pull apart the header into the DTLS1_RECORD */
1744 version = (ssl_major << 8) | ssl_minor;
1746 /* sequence number is 64 bits, with top 2 bytes = epoch */
1749 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1754 /* Lets check version */
1755 if (!s->first_packet) {
1756 if (version != s->version) {
1757 /* unexpected version, silently discard */
1759 RECORD_LAYER_reset_packet_length(&s->rlayer);
1764 if ((version & 0xff00) != (s->version & 0xff00)) {
1765 /* wrong version, silently discard record */
1767 RECORD_LAYER_reset_packet_length(&s->rlayer);
1771 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1772 /* record too long, silently discard it */
1774 RECORD_LAYER_reset_packet_length(&s->rlayer);
1778 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1781 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1784 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1785 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1787 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1788 /* this packet contained a partial record, dump it */
1789 if (rret <= 0 || n != more) {
1791 RECORD_LAYER_reset_packet_length(&s->rlayer);
1796 * now n == rr->length, and s->packet_length ==
1797 * DTLS1_RT_HEADER_LENGTH + rr->length
1800 /* set state for later operations */
1801 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1803 /* match epochs. NULL means the packet is dropped on the floor */
1804 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1805 if (bitmap == NULL) {
1807 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1808 goto again; /* get another record */
1810 #ifndef OPENSSL_NO_SCTP
1811 /* Only do replay check if no SCTP bio */
1812 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1814 /* Check whether this is a repeat, or aged record. */
1816 * TODO: Does it make sense to have replay protection in epoch 0 where
1817 * we have no integrity negotiated yet?
1819 if (!dtls1_record_replay_check(s, bitmap)) {
1821 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1822 goto again; /* get another record */
1824 #ifndef OPENSSL_NO_SCTP
1828 /* just read a 0 length packet */
1829 if (rr->length == 0)
1833 * If this record is from the next epoch (either HM or ALERT), and a
1834 * handshake is currently in progress, buffer it since it cannot be
1835 * processed at this time.
1837 if (is_next_epoch) {
1838 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1839 if (dtls1_buffer_record
1840 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1845 RECORD_LAYER_reset_packet_length(&s->rlayer);
1849 if (!dtls1_process_record(s, bitmap)) {
1851 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1852 goto again; /* get another record */