2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include "../ssl_locl.h"
11 #include "internal/constant_time_locl.h"
12 #include <openssl/rand.h>
13 #include "record_locl.h"
15 static const unsigned char ssl3_pad_1[48] = {
16 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36,
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
24 static const unsigned char ssl3_pad_2[48] = {
25 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c, 0x5c,
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
34 * Clear the contents of an SSL3_RECORD but retain any memory allocated
36 void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
41 for (i = 0; i < num_recs; i++) {
44 memset(&r[i], 0, sizeof(*r));
49 void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
53 for (i = 0; i < num_recs; i++) {
54 OPENSSL_free(r[i].comp);
59 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
61 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
65 * Peeks ahead into "read_ahead" data to see if we have a whole record waiting
66 * for us in the buffer.
68 static int ssl3_record_app_data_waiting(SSL *s)
74 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
76 p = SSL3_BUFFER_get_buf(rbuf);
80 left = SSL3_BUFFER_get_left(rbuf);
82 if (left < SSL3_RT_HEADER_LENGTH)
85 p += SSL3_BUFFER_get_offset(rbuf);
88 * We only check the type and record length, we will sanity check version
91 if (*p != SSL3_RT_APPLICATION_DATA)
97 if (left < SSL3_RT_HEADER_LENGTH + len)
104 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
105 * will be processed per call to ssl3_get_record. Without this limit an
106 * attacker could send empty records at a faster rate than we can process and
107 * cause ssl3_get_record to loop forever.
109 #define MAX_EMPTY_RECORDS 32
111 #define SSL2_RT_HEADER_LENGTH 2
113 * Call this to get new input records.
114 * It will return <= 0 if more data is needed, normally due to an error
115 * or non-blocking IO.
116 * When it finishes, |numrpipes| records have been decoded. For each record 'i':
117 * rr[i].type - is the type of record
119 * rr[i].length, - number of bytes
120 * Multiple records will only be returned if the record types are all
121 * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
124 /* used only by ssl3_read_bytes */
125 int ssl3_get_record(SSL *s)
128 int enc_err, rret, ret = -1;
135 unsigned char md[EVP_MAX_MD_SIZE];
136 unsigned int version;
139 size_t num_recs = 0, max_recs, j;
140 PACKET pkt, sslv2pkt;
142 rr = RECORD_LAYER_get_rrec(&s->rlayer);
143 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
144 max_recs = s->max_pipelines;
150 /* check if we have the header */
151 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
152 (RECORD_LAYER_get_packet_length(&s->rlayer)
153 < SSL3_RT_HEADER_LENGTH)) {
157 rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
158 SSL3_BUFFER_get_len(rbuf), 0,
159 num_recs == 0 ? 1 : 0, &n);
161 return rret; /* error or non-blocking */
162 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
164 p = RECORD_LAYER_get_packet(&s->rlayer);
165 if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
166 RECORD_LAYER_get_packet_length(&s->rlayer))) {
167 al = SSL_AD_INTERNAL_ERROR;
168 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
172 if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
173 || !PACKET_get_1(&sslv2pkt, &type)) {
174 al = SSL_AD_INTERNAL_ERROR;
175 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
179 * The first record received by the server may be a V2ClientHello.
181 if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
182 && (sslv2len & 0x8000) != 0
183 && (type == SSL2_MT_CLIENT_HELLO)) {
187 * |num_recs| here will actually always be 0 because
188 * |num_recs > 0| only ever occurs when we are processing
189 * multiple app data records - which we know isn't the case here
190 * because it is an SSLv2ClientHello. We keep it using
191 * |num_recs| for the sake of consistency
193 rr[num_recs].type = SSL3_RT_HANDSHAKE;
194 rr[num_recs].rec_version = SSL2_VERSION;
196 rr[num_recs].length = sslv2len & 0x7fff;
198 if (rr[num_recs].length > SSL3_BUFFER_get_len(rbuf)
199 - SSL2_RT_HEADER_LENGTH) {
200 al = SSL_AD_RECORD_OVERFLOW;
201 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
205 if (rr[num_recs].length < MIN_SSL2_RECORD_LEN) {
206 al = SSL_AD_HANDSHAKE_FAILURE;
207 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
211 /* SSLv3+ style record */
213 * TODO(TLS1.3): This callback only provides the "outer" record
214 * type to the callback. Somehow we need to pass the "inner"
218 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
219 s->msg_callback_arg);
221 /* Pull apart the header into the SSL3_RECORD */
222 if (!PACKET_get_1(&pkt, &type)
223 || !PACKET_get_net_2(&pkt, &version)
224 || !PACKET_get_net_2_len(&pkt, &rr[num_recs].length)) {
225 al = SSL_AD_INTERNAL_ERROR;
226 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_R_INTERNAL_ERROR);
229 rr[num_recs].type = type;
230 rr[num_recs].rec_version = version;
232 /* Lets check version. In TLSv1.3 we ignore this field */
233 if (!s->first_packet && !SSL_IS_TLS13(s)
234 && version != (unsigned int)s->version) {
235 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_WRONG_VERSION_NUMBER);
236 if ((s->version & 0xFF00) == (version & 0xFF00)
237 && !s->enc_write_ctx && !s->write_hash) {
238 if (rr->type == SSL3_RT_ALERT) {
240 * The record is using an incorrect version number,
241 * but what we've got appears to be an alert. We
242 * haven't read the body yet to check whether its a
243 * fatal or not - but chances are it is. We probably
244 * shouldn't send a fatal alert back. We'll just
250 * Send back error using their minor version number :-)
252 s->version = (unsigned short)version;
254 al = SSL_AD_PROTOCOL_VERSION;
258 if ((version >> 8) != SSL3_VERSION_MAJOR) {
259 if (RECORD_LAYER_is_first_record(&s->rlayer)) {
260 /* Go back to start of packet, look at the five bytes
262 p = RECORD_LAYER_get_packet(&s->rlayer);
263 if (strncmp((char *)p, "GET ", 4) == 0 ||
264 strncmp((char *)p, "POST ", 5) == 0 ||
265 strncmp((char *)p, "HEAD ", 5) == 0 ||
266 strncmp((char *)p, "PUT ", 4) == 0) {
267 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_HTTP_REQUEST);
269 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
270 SSLerr(SSL_F_SSL3_GET_RECORD,
271 SSL_R_HTTPS_PROXY_REQUEST);
275 /* Doesn't look like TLS - don't send an alert */
276 SSLerr(SSL_F_SSL3_GET_RECORD,
277 SSL_R_WRONG_VERSION_NUMBER);
280 SSLerr(SSL_F_SSL3_GET_RECORD,
281 SSL_R_WRONG_VERSION_NUMBER);
282 al = SSL_AD_PROTOCOL_VERSION;
287 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL
288 && rr[num_recs].type != SSL3_RT_APPLICATION_DATA) {
289 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
290 al = SSL_AD_UNEXPECTED_MESSAGE;
294 if (rr[num_recs].length >
295 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
296 al = SSL_AD_RECORD_OVERFLOW;
297 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_PACKET_LENGTH_TOO_LONG);
302 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
306 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
307 * Calculate how much more data we need to read for the rest of the
310 if (rr[num_recs].rec_version == SSL2_VERSION) {
311 more = rr[num_recs].length + SSL2_RT_HEADER_LENGTH
312 - SSL3_RT_HEADER_LENGTH;
314 more = rr[num_recs].length;
317 /* now s->packet_length == SSL3_RT_HEADER_LENGTH */
319 rret = ssl3_read_n(s, more, more, 1, 0, &n);
321 return rret; /* error or non-blocking io */
324 /* set state for later operations */
325 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
328 * At this point, s->packet_length == SSL3_RT_HEADER_LENGTH + rr->length,
329 * or s->packet_length == SSL2_RT_HEADER_LENGTH + rr->length
330 * and we have that many bytes in s->packet
332 if (rr[num_recs].rec_version == SSL2_VERSION) {
334 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
337 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
341 * ok, we can now read from 's->packet' data into 'rr' rr->input points
342 * at rr->length bytes, which need to be copied into rr->data by either
343 * the decryption or by the decompression When the data is 'copied' into
344 * the rr->data buffer, rr->input will be pointed at the new buffer
348 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
349 * bytes of encrypted compressed stuff.
352 /* check is not needed I believe */
353 if (rr[num_recs].length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
354 al = SSL_AD_RECORD_OVERFLOW;
355 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
359 /* decrypt in place in 'rr->input' */
360 rr[num_recs].data = rr[num_recs].input;
361 rr[num_recs].orig_len = rr[num_recs].length;
363 /* Mark this record as not read by upper layers yet */
364 rr[num_recs].read = 0;
368 /* we have pulled in a full packet so zero things */
369 RECORD_LAYER_reset_packet_length(&s->rlayer);
370 RECORD_LAYER_clear_first_record(&s->rlayer);
371 } while (num_recs < max_recs
372 && rr[num_recs - 1].type == SSL3_RT_APPLICATION_DATA
373 && SSL_USE_EXPLICIT_IV(s)
374 && s->enc_read_ctx != NULL
375 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
376 & EVP_CIPH_FLAG_PIPELINE)
377 && ssl3_record_app_data_waiting(s));
380 * If in encrypt-then-mac mode calculate mac from encrypted record. All
381 * the details below are public so no timing details can leak.
383 if (SSL_USE_ETM(s) && s->read_hash) {
385 /* TODO(size_t): convert this to do size_t properly */
386 imac_size = EVP_MD_CTX_size(s->read_hash);
388 al = SSL_AD_INTERNAL_ERROR;
389 SSLerr(SSL_F_SSL3_GET_RECORD, ERR_LIB_EVP);
392 mac_size = (size_t)imac_size;
393 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
394 for (j = 0; j < num_recs; j++) {
395 if (rr[j].length < mac_size) {
396 al = SSL_AD_DECODE_ERROR;
397 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
400 rr[j].length -= mac_size;
401 mac = rr[j].data + rr[j].length;
402 i = s->method->ssl3_enc->mac(s, &rr[j], md, 0 /* not send */ );
403 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
404 al = SSL_AD_BAD_RECORD_MAC;
405 SSLerr(SSL_F_SSL3_GET_RECORD,
406 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
412 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
416 * 0: (in non-constant time) if the record is publically invalid.
417 * 1: if the padding is valid
418 * -1: if the padding is invalid
421 al = SSL_AD_DECRYPTION_FAILED;
422 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
426 printf("dec %"OSSLzu"\n", rr->length);
429 for (z = 0; z < rr->length; z++)
430 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
435 /* r->length is now the compressed data plus mac */
436 if ((sess != NULL) &&
437 (s->enc_read_ctx != NULL) &&
438 (EVP_MD_CTX_md(s->read_hash) != NULL) && !SSL_USE_ETM(s)) {
439 /* s->read_hash != NULL => mac_size != -1 */
440 unsigned char *mac = NULL;
441 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
443 mac_size = EVP_MD_CTX_size(s->read_hash);
444 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
446 for (j = 0; j < num_recs; j++) {
448 * orig_len is the length of the record before any padding was
449 * removed. This is public information, as is the MAC in use,
450 * therefore we can safely process the record in a different amount
451 * of time if it's too short to possibly contain a MAC.
453 if (rr[j].orig_len < mac_size ||
454 /* CBC records must have a padding length byte too. */
455 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
456 rr[j].orig_len < mac_size + 1)) {
457 al = SSL_AD_DECODE_ERROR;
458 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_LENGTH_TOO_SHORT);
462 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
464 * We update the length so that the TLS header bytes can be
465 * constructed correctly but we need to extract the MAC in
466 * constant time from within the record, without leaking the
467 * contents of the padding bytes.
470 ssl3_cbc_copy_mac(mac_tmp, &rr[j], mac_size);
471 rr[j].length -= mac_size;
474 * In this case there's no padding, so |rec->orig_len| equals
475 * |rec->length| and we checked that there's enough bytes for
478 rr[j].length -= mac_size;
479 mac = &rr[j].data[rr[j].length];
482 i = s->method->ssl3_enc->mac(s, &rr[j], md, 0 /* not send */ );
483 if (i == 0 || mac == NULL
484 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
486 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
493 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
494 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
495 * failure is directly visible from the ciphertext anyway, we should
496 * not reveal which kind of error occurred -- this might become
497 * visible to an attacker (e.g. via a logfile)
499 al = SSL_AD_BAD_RECORD_MAC;
500 SSLerr(SSL_F_SSL3_GET_RECORD,
501 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
505 for (j = 0; j < num_recs; j++) {
506 /* rr[j].length is now just compressed */
507 if (s->expand != NULL) {
508 if (rr[j].length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
509 al = SSL_AD_RECORD_OVERFLOW;
510 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_COMPRESSED_LENGTH_TOO_LONG);
513 if (!ssl3_do_uncompress(s, &rr[j])) {
514 al = SSL_AD_DECOMPRESSION_FAILURE;
515 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_DECOMPRESSION);
520 if (SSL_IS_TLS13(s) && s->enc_read_ctx != NULL) {
523 if (rr[j].length == 0) {
524 al = SSL_AD_UNEXPECTED_MESSAGE;
525 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
529 /* Strip trailing padding */
530 for (end = rr[j].length - 1; end > 0 && rr[j].data[end] == 0; end--)
534 rr[j].type = rr[j].data[end];
535 if (rr[j].type != SSL3_RT_APPLICATION_DATA
536 && rr[j].type != SSL3_RT_ALERT
537 && rr[j].type != SSL3_RT_HANDSHAKE) {
538 al = SSL_AD_UNEXPECTED_MESSAGE;
539 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
544 if (rr[j].length > SSL3_RT_MAX_PLAIN_LENGTH) {
545 al = SSL_AD_RECORD_OVERFLOW;
546 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
552 * So at this point the following is true
553 * rr[j].type is the type of record
554 * rr[j].length == number of bytes in record
555 * rr[j].off == offset to first valid byte
556 * rr[j].data == where to take bytes from, increment after use :-).
559 /* just read a 0 length packet */
560 if (rr[j].length == 0) {
561 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
562 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
563 > MAX_EMPTY_RECORDS) {
564 al = SSL_AD_UNEXPECTED_MESSAGE;
565 SSLerr(SSL_F_SSL3_GET_RECORD, SSL_R_RECORD_TOO_SMALL);
569 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
573 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
577 ssl3_send_alert(s, SSL3_AL_FATAL, al);
582 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
584 #ifndef OPENSSL_NO_COMP
587 if (rr->comp == NULL) {
588 rr->comp = (unsigned char *)
589 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
591 if (rr->comp == NULL)
594 /* TODO(size_t): Convert this call */
595 i = COMP_expand_block(ssl->expand, rr->comp,
596 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
606 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
608 #ifndef OPENSSL_NO_COMP
611 /* TODO(size_t): Convert this call */
612 i = COMP_compress_block(ssl->compress, wr->data,
613 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
614 wr->input, (int)wr->length);
620 wr->input = wr->data;
626 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|
629 * 0: (in non-constant time) if the record is publically invalid (i.e. too
631 * 1: if the record's padding is valid / the encryption was successful.
632 * -1: if the record's padding is invalid or, if sending, an internal error
635 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int send)
640 size_t bs, mac_size = 0;
642 const EVP_CIPHER *enc;
646 * We shouldn't ever be called with more than one record in the SSLv3 case
651 ds = s->enc_write_ctx;
652 if (s->enc_write_ctx == NULL)
655 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
657 ds = s->enc_read_ctx;
658 if (s->enc_read_ctx == NULL)
661 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
664 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
665 memmove(rec->data, rec->input, rec->length);
666 rec->input = rec->data;
669 /* TODO(size_t): Convert this call */
670 bs = EVP_CIPHER_CTX_block_size(ds);
674 if ((bs != 1) && send) {
677 /* we need to add 'i-1' padding bytes */
680 * the last of these zero bytes will be overwritten with the
683 memset(&rec->input[rec->length], 0, i);
685 rec->input[l - 1] = (unsigned char)(i - 1);
689 if (l == 0 || l % bs != 0)
691 /* otherwise, rec->length >= bs */
694 /* TODO(size_t): Convert this call */
695 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
698 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
699 /* TODO(size_t): convert me */
700 imac_size = EVP_MD_CTX_size(s->read_hash);
703 mac_size = (size_t)imac_size;
705 if ((bs != 1) && !send)
706 return ssl3_cbc_remove_padding(rec, bs, mac_size);
711 #define MAX_PADDING 256
713 * tls1_enc encrypts/decrypts |n_recs| in |recs|.
716 * 0: (in non-constant time) if the record is publically invalid (i.e. too
718 * 1: if the record's padding is valid / the encryption was successful.
719 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
720 * an internal error occurred.
722 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int send)
725 size_t reclen[SSL_MAX_PIPELINES];
726 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
727 int i, pad = 0, ret, tmpr;
728 size_t bs, mac_size = 0, ctr, padnum, loop;
729 unsigned char padval;
731 const EVP_CIPHER *enc;
734 if (EVP_MD_CTX_md(s->write_hash)) {
735 int n = EVP_MD_CTX_size(s->write_hash);
736 OPENSSL_assert(n >= 0);
738 ds = s->enc_write_ctx;
739 if (s->enc_write_ctx == NULL)
743 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
744 /* For TLSv1.1 and later explicit IV */
745 if (SSL_USE_EXPLICIT_IV(s)
746 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
747 ivlen = EVP_CIPHER_iv_length(enc);
751 for (ctr = 0; ctr < n_recs; ctr++) {
752 if (recs[ctr].data != recs[ctr].input) {
754 * we can't write into the input stream: Can this ever
757 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
759 } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
760 SSLerr(SSL_F_TLS1_ENC, ERR_R_INTERNAL_ERROR);
767 if (EVP_MD_CTX_md(s->read_hash)) {
768 int n = EVP_MD_CTX_size(s->read_hash);
769 OPENSSL_assert(n >= 0);
771 ds = s->enc_read_ctx;
772 if (s->enc_read_ctx == NULL)
775 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
778 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
779 for (ctr = 0; ctr < n_recs; ctr++) {
780 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
781 recs[ctr].input = recs[ctr].data;
785 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
788 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
789 & EVP_CIPH_FLAG_PIPELINE)) {
791 * We shouldn't have been called with pipeline data if the
792 * cipher doesn't support pipelining
794 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
798 for (ctr = 0; ctr < n_recs; ctr++) {
799 reclen[ctr] = recs[ctr].length;
801 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
802 & EVP_CIPH_FLAG_AEAD_CIPHER) {
805 seq = send ? RECORD_LAYER_get_write_sequence(&s->rlayer)
806 : RECORD_LAYER_get_read_sequence(&s->rlayer);
808 if (SSL_IS_DTLS(s)) {
809 /* DTLS does not support pipelining */
810 unsigned char dtlsseq[9], *p = dtlsseq;
812 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
813 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
814 memcpy(p, &seq[2], 6);
815 memcpy(buf[ctr], dtlsseq, 8);
817 memcpy(buf[ctr], seq, 8);
818 for (i = 7; i >= 0; i--) { /* increment */
825 buf[ctr][8] = recs[ctr].type;
826 buf[ctr][9] = (unsigned char)(s->version >> 8);
827 buf[ctr][10] = (unsigned char)(s->version);
828 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
829 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
830 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
831 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
837 recs[ctr].length += pad;
840 } else if ((bs != 1) && send) {
841 padnum = bs - (reclen[ctr] % bs);
843 /* Add weird padding of upto 256 bytes */
845 if (padnum > MAX_PADDING)
847 /* we need to add 'padnum' padding bytes of value padval */
848 padval = (unsigned char)(padnum - 1);
849 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
850 recs[ctr].input[loop] = padval;
851 reclen[ctr] += padnum;
852 recs[ctr].length += padnum;
856 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
861 unsigned char *data[SSL_MAX_PIPELINES];
863 /* Set the output buffers */
864 for (ctr = 0; ctr < n_recs; ctr++) {
865 data[ctr] = recs[ctr].data;
867 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
868 (int)n_recs, data) <= 0) {
869 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
871 /* Set the input buffers */
872 for (ctr = 0; ctr < n_recs; ctr++) {
873 data[ctr] = recs[ctr].input;
875 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
876 (int)n_recs, data) <= 0
877 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
878 (int)n_recs, reclen) <= 0) {
879 SSLerr(SSL_F_TLS1_ENC, SSL_R_PIPELINE_FAILURE);
884 /* TODO(size_t): Convert this call */
885 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
886 (unsigned int)reclen[0]);
887 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
888 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
891 return -1; /* AEAD can fail to verify MAC */
893 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
894 for (ctr = 0; ctr < n_recs; ctr++) {
895 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
896 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
897 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
899 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
900 for (ctr = 0; ctr < n_recs; ctr++) {
901 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
902 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
903 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
909 if (!SSL_USE_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
910 imac_size = EVP_MD_CTX_size(s->read_hash);
913 mac_size = (size_t)imac_size;
915 if ((bs != 1) && !send) {
917 for (ctr = 0; ctr < n_recs; ctr++) {
918 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
920 * If tmpret == 0 then this means publicly invalid so we can
921 * short circuit things here. Otherwise we must respect constant
926 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
931 for (ctr = 0; ctr < n_recs; ctr++) {
932 recs[ctr].length -= pad;
939 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send)
941 unsigned char *mac_sec, *seq;
942 const EVP_MD_CTX *hash;
943 unsigned char *p, rec_char;
949 mac_sec = &(ssl->s3->write_mac_secret[0]);
950 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
951 hash = ssl->write_hash;
953 mac_sec = &(ssl->s3->read_mac_secret[0]);
954 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
955 hash = ssl->read_hash;
958 t = EVP_MD_CTX_size(hash);
962 npad = (48 / md_size) * md_size;
965 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
966 ssl3_cbc_record_digest_supported(hash)) {
968 * This is a CBC-encrypted record. We must avoid leaking any
969 * timing-side channel information about how many blocks of data we
970 * are hashing because that gives an attacker a timing-oracle.
974 * npad is, at most, 48 bytes and that's with MD5:
975 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
977 * With SHA-1 (the largest hash speced for SSLv3) the hash size
978 * goes up 4, but npad goes down by 8, resulting in a smaller
981 unsigned char header[75];
983 memcpy(header + j, mac_sec, md_size);
985 memcpy(header + j, ssl3_pad_1, npad);
987 memcpy(header + j, seq, 8);
989 header[j++] = rec->type;
990 header[j++] = (unsigned char)(rec->length >> 8);
991 header[j++] = (unsigned char)(rec->length & 0xff);
993 /* Final param == is SSLv3 */
994 if (ssl3_cbc_digest_record(hash,
997 rec->length + md_size, rec->orig_len,
998 mac_sec, md_size, 1) <= 0)
1001 unsigned int md_size_u;
1002 /* Chop the digest off the end :-) */
1003 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1008 rec_char = rec->type;
1010 s2n(rec->length, p);
1011 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1012 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1013 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1014 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1015 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1016 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1017 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1018 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1019 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1020 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1021 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1022 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1023 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1024 EVP_MD_CTX_reset(md_ctx);
1028 EVP_MD_CTX_free(md_ctx);
1031 ssl3_record_sequence_update(seq);
1035 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int send)
1041 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1042 unsigned char header[13];
1043 int stream_mac = (send ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1044 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1048 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1049 hash = ssl->write_hash;
1051 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1052 hash = ssl->read_hash;
1055 t = EVP_MD_CTX_size(hash);
1056 OPENSSL_assert(t >= 0);
1059 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1063 hmac = EVP_MD_CTX_new();
1064 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash))
1069 if (SSL_IS_DTLS(ssl)) {
1070 unsigned char dtlsseq[8], *p = dtlsseq;
1072 s2n(send ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1073 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1074 memcpy(p, &seq[2], 6);
1076 memcpy(header, dtlsseq, 8);
1078 memcpy(header, seq, 8);
1080 header[8] = rec->type;
1081 header[9] = (unsigned char)(ssl->version >> 8);
1082 header[10] = (unsigned char)(ssl->version);
1083 header[11] = (unsigned char)(rec->length >> 8);
1084 header[12] = (unsigned char)(rec->length & 0xff);
1086 if (!send && !SSL_USE_ETM(ssl) &&
1087 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1088 ssl3_cbc_record_digest_supported(mac_ctx)) {
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.
1094 /* Final param == not SSLv3 */
1095 if (ssl3_cbc_digest_record(mac_ctx,
1098 rec->length + md_size, rec->orig_len,
1099 ssl->s3->read_mac_secret,
1100 ssl->s3->read_mac_secret_size, 0) <= 0) {
1101 EVP_MD_CTX_free(hmac);
1105 /* TODO(size_t): Convert these calls */
1106 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1107 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1108 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1109 EVP_MD_CTX_free(hmac);
1112 if (!send && !SSL_USE_ETM(ssl) && FIPS_mode())
1113 if (!tls_fips_digest_extra(ssl->enc_read_ctx,
1114 mac_ctx, rec->input,
1115 rec->length, rec->orig_len)) {
1116 EVP_MD_CTX_free(hmac);
1121 EVP_MD_CTX_free(hmac);
1124 fprintf(stderr, "seq=");
1127 for (z = 0; z < 8; z++)
1128 fprintf(stderr, "%02X ", seq[z]);
1129 fprintf(stderr, "\n");
1131 fprintf(stderr, "rec=");
1134 for (z = 0; z < rec->length; z++)
1135 fprintf(stderr, "%02X ", rec->data[z]);
1136 fprintf(stderr, "\n");
1140 if (!SSL_IS_DTLS(ssl)) {
1141 for (i = 7; i >= 0; i--) {
1150 for (z = 0; z < md_size; z++)
1151 fprintf(stderr, "%02X ", md[z]);
1152 fprintf(stderr, "\n");
1159 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1160 * record in |rec| by updating |rec->length| in constant time.
1162 * block_size: the block size of the cipher used to encrypt the record.
1164 * 0: (in non-constant time) if the record is publicly invalid.
1165 * 1: if the padding was valid
1168 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1169 size_t block_size, size_t mac_size)
1171 size_t padding_length;
1173 const size_t overhead = 1 /* padding length byte */ + mac_size;
1176 * These lengths are all public so we can test them in non-constant time.
1178 if (overhead > rec->length)
1181 padding_length = rec->data[rec->length - 1];
1182 good = constant_time_ge_s(rec->length, padding_length + overhead);
1183 /* SSLv3 requires that the padding is minimal. */
1184 good &= constant_time_ge_s(block_size, padding_length + 1);
1185 rec->length -= good & (padding_length + 1);
1186 return constant_time_select_int_s(good, 1, -1);
1190 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1191 * record in |rec| in constant time and returns 1 if the padding is valid and
1192 * -1 otherwise. It also removes any explicit IV from the start of the record
1193 * without leaking any timing about whether there was enough space after the
1194 * padding was removed.
1196 * block_size: the block size of the cipher used to encrypt the record.
1198 * 0: (in non-constant time) if the record is publicly invalid.
1199 * 1: if the padding was valid
1202 int tls1_cbc_remove_padding(const SSL *s,
1204 size_t block_size, size_t mac_size)
1207 size_t padding_length, to_check, i;
1208 const size_t overhead = 1 /* padding length byte */ + mac_size;
1209 /* Check if version requires explicit IV */
1210 if (SSL_USE_EXPLICIT_IV(s)) {
1212 * These lengths are all public so we can test them in non-constant
1215 if (overhead + block_size > rec->length)
1217 /* We can now safely skip explicit IV */
1218 rec->data += block_size;
1219 rec->input += block_size;
1220 rec->length -= block_size;
1221 rec->orig_len -= block_size;
1222 } else if (overhead > rec->length)
1225 padding_length = rec->data[rec->length - 1];
1227 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1228 EVP_CIPH_FLAG_AEAD_CIPHER) {
1229 /* padding is already verified */
1230 rec->length -= padding_length + 1;
1234 good = constant_time_ge_s(rec->length, overhead + padding_length);
1236 * The padding consists of a length byte at the end of the record and
1237 * then that many bytes of padding, all with the same value as the length
1238 * byte. Thus, with the length byte included, there are i+1 bytes of
1239 * padding. We can't check just |padding_length+1| bytes because that
1240 * leaks decrypted information. Therefore we always have to check the
1241 * maximum amount of padding possible. (Again, the length of the record
1242 * is public information so we can use it.)
1244 to_check = 256; /* maximum amount of padding, inc length byte. */
1245 if (to_check > rec->length)
1246 to_check = rec->length;
1248 for (i = 0; i < to_check; i++) {
1249 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1250 unsigned char b = rec->data[rec->length - 1 - i];
1252 * The final |padding_length+1| bytes should all have the value
1253 * |padding_length|. Therefore the XOR should be zero.
1255 good &= ~(mask & (padding_length ^ b));
1259 * If any of the final |padding_length+1| bytes had the wrong value, one
1260 * or more of the lower eight bits of |good| will be cleared.
1262 good = constant_time_eq_s(0xff, good & 0xff);
1263 rec->length -= good & (padding_length + 1);
1265 return constant_time_select_int_s(good, 1, -1);
1269 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1270 * constant time (independent of the concrete value of rec->length, which may
1271 * vary within a 256-byte window).
1273 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1277 * rec->orig_len >= md_size
1278 * md_size <= EVP_MAX_MD_SIZE
1280 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1281 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1282 * a single or pair of cache-lines, then the variable memory accesses don't
1283 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1284 * not multi-core and are not considered vulnerable to cache-timing attacks.
1286 #define CBC_MAC_ROTATE_IN_PLACE
1288 void ssl3_cbc_copy_mac(unsigned char *out,
1289 const SSL3_RECORD *rec, size_t md_size)
1291 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1292 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1293 unsigned char *rotated_mac;
1295 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1299 * mac_end is the index of |rec->data| just after the end of the MAC.
1301 size_t mac_end = rec->length;
1302 size_t mac_start = mac_end - md_size;
1304 * scan_start contains the number of bytes that we can ignore because the
1305 * MAC's position can only vary by 255 bytes.
1307 size_t scan_start = 0;
1310 size_t rotate_offset;
1312 OPENSSL_assert(rec->orig_len >= md_size);
1313 OPENSSL_assert(md_size <= EVP_MAX_MD_SIZE);
1315 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1316 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1319 /* This information is public so it's safe to branch based on it. */
1320 if (rec->orig_len > md_size + 255 + 1)
1321 scan_start = rec->orig_len - (md_size + 255 + 1);
1323 * div_spoiler contains a multiple of md_size that is used to cause the
1324 * modulo operation to be constant time. Without this, the time varies
1325 * based on the amount of padding when running on Intel chips at least.
1326 * The aim of right-shifting md_size is so that the compiler doesn't
1327 * figure out that it can remove div_spoiler as that would require it to
1328 * prove that md_size is always even, which I hope is beyond it.
1330 div_spoiler = md_size >> 1;
1331 div_spoiler <<= (sizeof(div_spoiler) - 1) * 8;
1332 rotate_offset = (div_spoiler + mac_start - scan_start) % md_size;
1334 memset(rotated_mac, 0, md_size);
1335 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1336 unsigned char mac_started = constant_time_ge_8_s(i, mac_start);
1337 unsigned char mac_ended = constant_time_ge_8_s(i, mac_end);
1338 unsigned char b = rec->data[i];
1339 rotated_mac[j++] |= b & mac_started & ~mac_ended;
1340 j &= constant_time_lt_s(j, md_size);
1343 /* Now rotate the MAC */
1344 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1346 for (i = 0; i < md_size; i++) {
1347 /* in case cache-line is 32 bytes, touch second line */
1348 ((volatile unsigned char *)rotated_mac)[rotate_offset ^ 32];
1349 out[j++] = rotated_mac[rotate_offset++];
1350 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1353 memset(out, 0, md_size);
1354 rotate_offset = md_size - rotate_offset;
1355 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1356 for (i = 0; i < md_size; i++) {
1357 for (j = 0; j < md_size; j++)
1358 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1360 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1365 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1373 unsigned char md[EVP_MAX_MD_SIZE];
1375 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1379 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1380 * and we have that many bytes in s->packet
1382 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1385 * ok, we can now read from 's->packet' data into 'rr' rr->input points
1386 * at rr->length bytes, which need to be copied into rr->data by either
1387 * the decryption or by the decompression When the data is 'copied' into
1388 * the rr->data buffer, rr->input will be pointed at the new buffer
1392 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1393 * bytes of encrypted compressed stuff.
1396 /* check is not needed I believe */
1397 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1398 al = SSL_AD_RECORD_OVERFLOW;
1399 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1403 /* decrypt in place in 'rr->input' */
1404 rr->data = rr->input;
1405 rr->orig_len = rr->length;
1407 if (SSL_USE_ETM(s) && s->read_hash) {
1409 mac_size = EVP_MD_CTX_size(s->read_hash);
1410 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1411 if (rr->orig_len < mac_size) {
1412 al = SSL_AD_DECODE_ERROR;
1413 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1416 rr->length -= mac_size;
1417 mac = rr->data + rr->length;
1418 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1419 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1420 al = SSL_AD_BAD_RECORD_MAC;
1421 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1422 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1427 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1430 * 0: (in non-constant time) if the record is publically invalid.
1431 * 1: if the padding is valid
1432 * -1: if the padding is invalid
1435 /* For DTLS we simply ignore bad packets. */
1437 RECORD_LAYER_reset_packet_length(&s->rlayer);
1441 printf("dec %ld\n", rr->length);
1444 for (z = 0; z < rr->length; z++)
1445 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1450 /* r->length is now the compressed data plus mac */
1451 if ((sess != NULL) && !SSL_USE_ETM(s) &&
1452 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1453 /* s->read_hash != NULL => mac_size != -1 */
1454 unsigned char *mac = NULL;
1455 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1457 /* TODO(size_t): Convert this to do size_t properly */
1458 imac_size = EVP_MD_CTX_size(s->read_hash);
1459 if (imac_size < 0) {
1460 al = SSL_AD_INTERNAL_ERROR;
1461 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, ERR_LIB_EVP);
1464 mac_size = (size_t)imac_size;
1465 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
1468 * orig_len is the length of the record before any padding was
1469 * removed. This is public information, as is the MAC in use,
1470 * therefore we can safely process the record in a different amount
1471 * of time if it's too short to possibly contain a MAC.
1473 if (rr->orig_len < mac_size ||
1474 /* CBC records must have a padding length byte too. */
1475 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1476 rr->orig_len < mac_size + 1)) {
1477 al = SSL_AD_DECODE_ERROR;
1478 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
1482 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1484 * We update the length so that the TLS header bytes can be
1485 * constructed correctly but we need to extract the MAC in
1486 * constant time from within the record, without leaking the
1487 * contents of the padding bytes.
1490 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
1491 rr->length -= mac_size;
1494 * In this case there's no padding, so |rec->orig_len| equals
1495 * |rec->length| and we checked that there's enough bytes for
1498 rr->length -= mac_size;
1499 mac = &rr->data[rr->length];
1502 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1503 if (i == 0 || mac == NULL
1504 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1506 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1511 /* decryption failed, silently discard message */
1513 RECORD_LAYER_reset_packet_length(&s->rlayer);
1517 /* r->length is now just compressed */
1518 if (s->expand != NULL) {
1519 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1520 al = SSL_AD_RECORD_OVERFLOW;
1521 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
1522 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1525 if (!ssl3_do_uncompress(s, rr)) {
1526 al = SSL_AD_DECOMPRESSION_FAILURE;
1527 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1532 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
1533 al = SSL_AD_RECORD_OVERFLOW;
1534 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
1540 * So at this point the following is true
1541 * ssl->s3->rrec.type is the type of record
1542 * ssl->s3->rrec.length == number of bytes in record
1543 * ssl->s3->rrec.off == offset to first valid byte
1544 * ssl->s3->rrec.data == where to take bytes from, increment
1548 /* we have pulled in a full packet so zero things */
1549 RECORD_LAYER_reset_packet_length(&s->rlayer);
1551 /* Mark receipt of record. */
1552 dtls1_record_bitmap_update(s, bitmap);
1557 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1563 * retrieve a buffered record that belongs to the current epoch, ie,
1566 #define dtls1_get_processed_record(s) \
1567 dtls1_retrieve_buffered_record((s), \
1568 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1571 * Call this to get a new input record.
1572 * It will return <= 0 if more data is needed, normally due to an error
1573 * or non-blocking IO.
1574 * When it finishes, one packet has been decoded and can be found in
1575 * ssl->s3->rrec.type - is the type of record
1576 * ssl->s3->rrec.data, - data
1577 * ssl->s3->rrec.length, - number of bytes
1579 /* used only by dtls1_read_bytes */
1580 int dtls1_get_record(SSL *s)
1582 int ssl_major, ssl_minor;
1586 unsigned char *p = NULL;
1587 unsigned short version;
1588 DTLS1_BITMAP *bitmap;
1589 unsigned int is_next_epoch;
1591 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1595 * The epoch may have changed. If so, process all the pending records.
1596 * This is a non-blocking operation.
1598 if (!dtls1_process_buffered_records(s))
1601 /* if we're renegotiating, then there may be buffered records */
1602 if (dtls1_get_processed_record(s))
1605 /* get something from the wire */
1607 /* check if we have the header */
1608 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1609 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1610 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1611 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1612 /* read timeout is handled by dtls1_read_bytes */
1614 return rret; /* error or non-blocking */
1616 /* this packet contained a partial record, dump it */
1617 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1618 DTLS1_RT_HEADER_LENGTH) {
1619 RECORD_LAYER_reset_packet_length(&s->rlayer);
1623 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1625 p = RECORD_LAYER_get_packet(&s->rlayer);
1627 if (s->msg_callback)
1628 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1629 s, s->msg_callback_arg);
1631 /* Pull apart the header into the DTLS1_RECORD */
1635 version = (ssl_major << 8) | ssl_minor;
1637 /* sequence number is 64 bits, with top 2 bytes = epoch */
1640 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1645 /* Lets check version */
1646 if (!s->first_packet) {
1647 if (version != s->version) {
1648 /* unexpected version, silently discard */
1650 RECORD_LAYER_reset_packet_length(&s->rlayer);
1655 if ((version & 0xff00) != (s->version & 0xff00)) {
1656 /* wrong version, silently discard record */
1658 RECORD_LAYER_reset_packet_length(&s->rlayer);
1662 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1663 /* record too long, silently discard it */
1665 RECORD_LAYER_reset_packet_length(&s->rlayer);
1669 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
1672 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
1675 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
1676 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
1678 rret = ssl3_read_n(s, more, more, 1, 1, &n);
1679 /* this packet contained a partial record, dump it */
1680 if (rret <= 0 || n != more) {
1682 RECORD_LAYER_reset_packet_length(&s->rlayer);
1687 * now n == rr->length, and s->packet_length ==
1688 * DTLS1_RT_HEADER_LENGTH + rr->length
1691 /* set state for later operations */
1692 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
1694 /* match epochs. NULL means the packet is dropped on the floor */
1695 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
1696 if (bitmap == NULL) {
1698 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1699 goto again; /* get another record */
1701 #ifndef OPENSSL_NO_SCTP
1702 /* Only do replay check if no SCTP bio */
1703 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
1705 /* Check whether this is a repeat, or aged record. */
1707 * TODO: Does it make sense to have replay protection in epoch 0 where
1708 * we have no integrity negotiated yet?
1710 if (!dtls1_record_replay_check(s, bitmap)) {
1712 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1713 goto again; /* get another record */
1715 #ifndef OPENSSL_NO_SCTP
1719 /* just read a 0 length packet */
1720 if (rr->length == 0)
1724 * If this record is from the next epoch (either HM or ALERT), and a
1725 * handshake is currently in progress, buffer it since it cannot be
1726 * processed at this time.
1728 if (is_next_epoch) {
1729 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
1730 if (dtls1_buffer_record
1731 (s, &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
1736 RECORD_LAYER_reset_packet_length(&s->rlayer);
1740 if (!dtls1_process_record(s, bitmap)) {
1742 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
1743 goto again; /* get another record */