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