1 /*
2 * Copyright 1995-2022 The OpenSSL Project Authors. All Rights Reserved.
3 *
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
8 */
9
10 #include "../ssl_local.h"
11 #include "internal/constant_time.h"
12 #include <openssl/rand.h>
13 #include "record_local.h"
14 #include "internal/cryptlib.h"
15
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
23 };
24
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
32 };
33
34 /*
35 * Clear the contents of an SSL3_RECORD but retain any memory allocated
36 */
SSL3_RECORD_clear(SSL3_RECORD * r,size_t num_recs)37 void SSL3_RECORD_clear(SSL3_RECORD *r, size_t num_recs)
38 {
39 unsigned char *comp;
40 size_t i;
41
42 for (i = 0; i < num_recs; i++) {
43 comp = r[i].comp;
44
45 memset(&r[i], 0, sizeof(*r));
46 r[i].comp = comp;
47 }
48 }
49
SSL3_RECORD_release(SSL3_RECORD * r,size_t num_recs)50 void SSL3_RECORD_release(SSL3_RECORD *r, size_t num_recs)
51 {
52 size_t i;
53
54 for (i = 0; i < num_recs; i++) {
55 OPENSSL_free(r[i].comp);
56 r[i].comp = NULL;
57 }
58 }
59
SSL3_RECORD_set_seq_num(SSL3_RECORD * r,const unsigned char * seq_num)60 void SSL3_RECORD_set_seq_num(SSL3_RECORD *r, const unsigned char *seq_num)
61 {
62 memcpy(r->seq_num, seq_num, SEQ_NUM_SIZE);
63 }
64
65 /*
66 * Peeks ahead into "read_ahead" data to see if we have a whole record waiting
67 * for us in the buffer.
68 */
ssl3_record_app_data_waiting(SSL * s)69 static int ssl3_record_app_data_waiting(SSL *s)
70 {
71 SSL3_BUFFER *rbuf;
72 size_t left, len;
73 unsigned char *p;
74
75 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
76
77 p = SSL3_BUFFER_get_buf(rbuf);
78 if (p == NULL)
79 return 0;
80
81 left = SSL3_BUFFER_get_left(rbuf);
82
83 if (left < SSL3_RT_HEADER_LENGTH)
84 return 0;
85
86 p += SSL3_BUFFER_get_offset(rbuf);
87
88 /*
89 * We only check the type and record length, we will sanity check version
90 * etc later
91 */
92 if (*p != SSL3_RT_APPLICATION_DATA)
93 return 0;
94
95 p += 3;
96 n2s(p, len);
97
98 if (left < SSL3_RT_HEADER_LENGTH + len)
99 return 0;
100
101 return 1;
102 }
103
early_data_count_ok(SSL * s,size_t length,size_t overhead,int send)104 int early_data_count_ok(SSL *s, size_t length, size_t overhead, int send)
105 {
106 uint32_t max_early_data;
107 SSL_SESSION *sess = s->session;
108
109 /*
110 * If we are a client then we always use the max_early_data from the
111 * session/psksession. Otherwise we go with the lowest out of the max early
112 * data set in the session and the configured max_early_data.
113 */
114 if (!s->server && sess->ext.max_early_data == 0) {
115 if (!ossl_assert(s->psksession != NULL
116 && s->psksession->ext.max_early_data > 0)) {
117 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_EARLY_DATA_COUNT_OK,
118 ERR_R_INTERNAL_ERROR);
119 return 0;
120 }
121 sess = s->psksession;
122 }
123
124 if (!s->server)
125 max_early_data = sess->ext.max_early_data;
126 else if (s->ext.early_data != SSL_EARLY_DATA_ACCEPTED)
127 max_early_data = s->recv_max_early_data;
128 else
129 max_early_data = s->recv_max_early_data < sess->ext.max_early_data
130 ? s->recv_max_early_data : sess->ext.max_early_data;
131
132 if (max_early_data == 0) {
133 SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
134 SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
135 return 0;
136 }
137
138 /* If we are dealing with ciphertext we need to allow for the overhead */
139 max_early_data += overhead;
140
141 if (s->early_data_count + length > max_early_data) {
142 SSLfatal(s, send ? SSL_AD_INTERNAL_ERROR : SSL_AD_UNEXPECTED_MESSAGE,
143 SSL_F_EARLY_DATA_COUNT_OK, SSL_R_TOO_MUCH_EARLY_DATA);
144 return 0;
145 }
146 s->early_data_count += length;
147
148 return 1;
149 }
150
151 /*
152 * MAX_EMPTY_RECORDS defines the number of consecutive, empty records that
153 * will be processed per call to ssl3_get_record. Without this limit an
154 * attacker could send empty records at a faster rate than we can process and
155 * cause ssl3_get_record to loop forever.
156 */
157 #define MAX_EMPTY_RECORDS 32
158
159 #define SSL2_RT_HEADER_LENGTH 2
160 /*-
161 * Call this to get new input records.
162 * It will return <= 0 if more data is needed, normally due to an error
163 * or non-blocking IO.
164 * When it finishes, |numrpipes| records have been decoded. For each record 'i':
165 * rr[i].type - is the type of record
166 * rr[i].data, - data
167 * rr[i].length, - number of bytes
168 * Multiple records will only be returned if the record types are all
169 * SSL3_RT_APPLICATION_DATA. The number of records returned will always be <=
170 * |max_pipelines|
171 */
172 /* used only by ssl3_read_bytes */
ssl3_get_record(SSL * s)173 int ssl3_get_record(SSL *s)
174 {
175 int enc_err, rret;
176 int i;
177 size_t more, n;
178 SSL3_RECORD *rr, *thisrr;
179 SSL3_BUFFER *rbuf;
180 SSL_SESSION *sess;
181 unsigned char *p;
182 unsigned char md[EVP_MAX_MD_SIZE];
183 unsigned int version;
184 size_t mac_size;
185 int imac_size;
186 size_t num_recs = 0, max_recs, j;
187 PACKET pkt, sslv2pkt;
188 size_t first_rec_len;
189 int using_ktls;
190
191 rr = RECORD_LAYER_get_rrec(&s->rlayer);
192 rbuf = RECORD_LAYER_get_rbuf(&s->rlayer);
193 max_recs = s->max_pipelines;
194 if (max_recs == 0)
195 max_recs = 1;
196 sess = s->session;
197
198 /*
199 * KTLS reads full records. If there is any data left,
200 * then it is from before enabling ktls.
201 */
202 using_ktls = BIO_get_ktls_recv(s->rbio) && SSL3_BUFFER_get_left(rbuf) == 0;
203
204 do {
205 thisrr = &rr[num_recs];
206
207 /* check if we have the header */
208 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
209 (RECORD_LAYER_get_packet_length(&s->rlayer)
210 < SSL3_RT_HEADER_LENGTH)) {
211 size_t sslv2len;
212 unsigned int type;
213
214 rret = ssl3_read_n(s, SSL3_RT_HEADER_LENGTH,
215 SSL3_BUFFER_get_len(rbuf), 0,
216 num_recs == 0 ? 1 : 0, &n);
217 if (rret <= 0) {
218 #ifndef OPENSSL_NO_KTLS
219 if (!BIO_get_ktls_recv(s->rbio) || rret == 0)
220 return rret; /* error or non-blocking */
221 switch (errno) {
222 case EBADMSG:
223 SSLfatal(s, SSL_AD_BAD_RECORD_MAC,
224 SSL_F_SSL3_GET_RECORD,
225 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
226 break;
227 case EMSGSIZE:
228 SSLfatal(s, SSL_AD_RECORD_OVERFLOW,
229 SSL_F_SSL3_GET_RECORD,
230 SSL_R_PACKET_LENGTH_TOO_LONG);
231 break;
232 case EINVAL:
233 SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
234 SSL_F_SSL3_GET_RECORD,
235 SSL_R_WRONG_VERSION_NUMBER);
236 break;
237 default:
238 break;
239 }
240 #endif
241 return rret;
242 }
243 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
244
245 p = RECORD_LAYER_get_packet(&s->rlayer);
246 if (!PACKET_buf_init(&pkt, RECORD_LAYER_get_packet(&s->rlayer),
247 RECORD_LAYER_get_packet_length(&s->rlayer))) {
248 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
249 ERR_R_INTERNAL_ERROR);
250 return -1;
251 }
252 sslv2pkt = pkt;
253 if (!PACKET_get_net_2_len(&sslv2pkt, &sslv2len)
254 || !PACKET_get_1(&sslv2pkt, &type)) {
255 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
256 ERR_R_INTERNAL_ERROR);
257 return -1;
258 }
259 /*
260 * The first record received by the server may be a V2ClientHello.
261 */
262 if (s->server && RECORD_LAYER_is_first_record(&s->rlayer)
263 && (sslv2len & 0x8000) != 0
264 && (type == SSL2_MT_CLIENT_HELLO)) {
265 /*
266 * SSLv2 style record
267 *
268 * |num_recs| here will actually always be 0 because
269 * |num_recs > 0| only ever occurs when we are processing
270 * multiple app data records - which we know isn't the case here
271 * because it is an SSLv2ClientHello. We keep it using
272 * |num_recs| for the sake of consistency
273 */
274 thisrr->type = SSL3_RT_HANDSHAKE;
275 thisrr->rec_version = SSL2_VERSION;
276
277 thisrr->length = sslv2len & 0x7fff;
278
279 if (thisrr->length > SSL3_BUFFER_get_len(rbuf)
280 - SSL2_RT_HEADER_LENGTH) {
281 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
282 SSL_R_PACKET_LENGTH_TOO_LONG);
283 return -1;
284 }
285
286 if (thisrr->length < MIN_SSL2_RECORD_LEN) {
287 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
288 SSL_R_LENGTH_TOO_SHORT);
289 return -1;
290 }
291 } else {
292 /* SSLv3+ style record */
293 if (s->msg_callback)
294 s->msg_callback(0, 0, SSL3_RT_HEADER, p, 5, s,
295 s->msg_callback_arg);
296
297 /* Pull apart the header into the SSL3_RECORD */
298 if (!PACKET_get_1(&pkt, &type)
299 || !PACKET_get_net_2(&pkt, &version)
300 || !PACKET_get_net_2_len(&pkt, &thisrr->length)) {
301 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
302 ERR_R_INTERNAL_ERROR);
303 return -1;
304 }
305 thisrr->type = type;
306 thisrr->rec_version = version;
307
308 /*
309 * Lets check version. In TLSv1.3 we only check this field
310 * when encryption is occurring (see later check). For the
311 * ServerHello after an HRR we haven't actually selected TLSv1.3
312 * yet, but we still treat it as TLSv1.3, so we must check for
313 * that explicitly
314 */
315 if (!s->first_packet && !SSL_IS_TLS13(s)
316 && s->hello_retry_request != SSL_HRR_PENDING
317 && version != (unsigned int)s->version) {
318 if ((s->version & 0xFF00) == (version & 0xFF00)
319 && !s->enc_write_ctx && !s->write_hash) {
320 if (thisrr->type == SSL3_RT_ALERT) {
321 /*
322 * The record is using an incorrect version number,
323 * but what we've got appears to be an alert. We
324 * haven't read the body yet to check whether its a
325 * fatal or not - but chances are it is. We probably
326 * shouldn't send a fatal alert back. We'll just
327 * end.
328 */
329 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
330 SSL_R_WRONG_VERSION_NUMBER);
331 return -1;
332 }
333 /*
334 * Send back error using their minor version number :-)
335 */
336 s->version = (unsigned short)version;
337 }
338 SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_SSL3_GET_RECORD,
339 SSL_R_WRONG_VERSION_NUMBER);
340 return -1;
341 }
342
343 if ((version >> 8) != SSL3_VERSION_MAJOR) {
344 if (RECORD_LAYER_is_first_record(&s->rlayer)) {
345 /* Go back to start of packet, look at the five bytes
346 * that we have. */
347 p = RECORD_LAYER_get_packet(&s->rlayer);
348 if (strncmp((char *)p, "GET ", 4) == 0 ||
349 strncmp((char *)p, "POST ", 5) == 0 ||
350 strncmp((char *)p, "HEAD ", 5) == 0 ||
351 strncmp((char *)p, "PUT ", 4) == 0) {
352 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
353 SSL_R_HTTP_REQUEST);
354 return -1;
355 } else if (strncmp((char *)p, "CONNE", 5) == 0) {
356 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
357 SSL_R_HTTPS_PROXY_REQUEST);
358 return -1;
359 }
360
361 /* Doesn't look like TLS - don't send an alert */
362 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_SSL3_GET_RECORD,
363 SSL_R_WRONG_VERSION_NUMBER);
364 return -1;
365 } else {
366 SSLfatal(s, SSL_AD_PROTOCOL_VERSION,
367 SSL_F_SSL3_GET_RECORD,
368 SSL_R_WRONG_VERSION_NUMBER);
369 return -1;
370 }
371 }
372
373 if (SSL_IS_TLS13(s)
374 && s->enc_read_ctx != NULL
375 && !using_ktls) {
376 if (thisrr->type != SSL3_RT_APPLICATION_DATA
377 && (thisrr->type != SSL3_RT_CHANGE_CIPHER_SPEC
378 || !SSL_IS_FIRST_HANDSHAKE(s))
379 && (thisrr->type != SSL3_RT_ALERT
380 || s->statem.enc_read_state
381 != ENC_READ_STATE_ALLOW_PLAIN_ALERTS)) {
382 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
383 SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
384 return -1;
385 }
386 if (thisrr->rec_version != TLS1_2_VERSION) {
387 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
388 SSL_R_WRONG_VERSION_NUMBER);
389 return -1;
390 }
391 }
392
393 if (thisrr->length >
394 SSL3_BUFFER_get_len(rbuf) - SSL3_RT_HEADER_LENGTH) {
395 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
396 SSL_R_PACKET_LENGTH_TOO_LONG);
397 return -1;
398 }
399 }
400
401 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
402 }
403
404 if (SSL_IS_TLS13(s)) {
405 size_t len = SSL3_RT_MAX_TLS13_ENCRYPTED_LENGTH;
406
407 /* KTLS strips the inner record type. */
408 if (using_ktls)
409 len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
410
411 if (thisrr->length > len) {
412 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
413 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
414 return -1;
415 }
416 } else {
417 size_t len = SSL3_RT_MAX_ENCRYPTED_LENGTH;
418
419 #ifndef OPENSSL_NO_COMP
420 /*
421 * If OPENSSL_NO_COMP is defined then SSL3_RT_MAX_ENCRYPTED_LENGTH
422 * does not include the compression overhead anyway.
423 */
424 if (s->expand == NULL)
425 len -= SSL3_RT_MAX_COMPRESSED_OVERHEAD;
426 #endif
427
428 /* KTLS may use all of the buffer */
429 if (using_ktls)
430 len = SSL3_BUFFER_get_left(rbuf);
431
432 if (thisrr->length > len) {
433 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
434 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
435 return -1;
436 }
437 }
438
439 /*
440 * s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data.
441 * Calculate how much more data we need to read for the rest of the
442 * record
443 */
444 if (thisrr->rec_version == SSL2_VERSION) {
445 more = thisrr->length + SSL2_RT_HEADER_LENGTH
446 - SSL3_RT_HEADER_LENGTH;
447 } else {
448 more = thisrr->length;
449 }
450
451 if (more > 0) {
452 /* now s->rlayer.packet_length == SSL3_RT_HEADER_LENGTH */
453
454 rret = ssl3_read_n(s, more, more, 1, 0, &n);
455 if (rret <= 0)
456 return rret; /* error or non-blocking io */
457 }
458
459 /* set state for later operations */
460 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
461
462 /*
463 * At this point, s->rlayer.packet_length == SSL3_RT_HEADER_LENGTH
464 * + thisrr->length, or s->rlayer.packet_length == SSL2_RT_HEADER_LENGTH
465 * + thisrr->length and we have that many bytes in s->rlayer.packet
466 */
467 if (thisrr->rec_version == SSL2_VERSION) {
468 thisrr->input =
469 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL2_RT_HEADER_LENGTH]);
470 } else {
471 thisrr->input =
472 &(RECORD_LAYER_get_packet(&s->rlayer)[SSL3_RT_HEADER_LENGTH]);
473 }
474
475 /*
476 * ok, we can now read from 's->rlayer.packet' data into 'thisrr'.
477 * thisrr->input points at thisrr->length bytes, which need to be copied
478 * into thisrr->data by either the decryption or by the decompression.
479 * When the data is 'copied' into the thisrr->data buffer,
480 * thisrr->input will be updated to point at the new buffer
481 */
482
483 /*
484 * We now have - encrypted [ MAC [ compressed [ plain ] ] ]
485 * thisrr->length bytes of encrypted compressed stuff.
486 */
487
488 /* decrypt in place in 'thisrr->input' */
489 thisrr->data = thisrr->input;
490 thisrr->orig_len = thisrr->length;
491
492 /* Mark this record as not read by upper layers yet */
493 thisrr->read = 0;
494
495 num_recs++;
496
497 /* we have pulled in a full packet so zero things */
498 RECORD_LAYER_reset_packet_length(&s->rlayer);
499 RECORD_LAYER_clear_first_record(&s->rlayer);
500 } while (num_recs < max_recs
501 && thisrr->type == SSL3_RT_APPLICATION_DATA
502 && SSL_USE_EXPLICIT_IV(s)
503 && s->enc_read_ctx != NULL
504 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx))
505 & EVP_CIPH_FLAG_PIPELINE)
506 && ssl3_record_app_data_waiting(s));
507
508 if (num_recs == 1
509 && thisrr->type == SSL3_RT_CHANGE_CIPHER_SPEC
510 && (SSL_IS_TLS13(s) || s->hello_retry_request != SSL_HRR_NONE)
511 && SSL_IS_FIRST_HANDSHAKE(s)) {
512 /*
513 * CCS messages must be exactly 1 byte long, containing the value 0x01
514 */
515 if (thisrr->length != 1 || thisrr->data[0] != 0x01) {
516 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SSL3_GET_RECORD,
517 SSL_R_INVALID_CCS_MESSAGE);
518 return -1;
519 }
520 /*
521 * CCS messages are ignored in TLSv1.3. We treat it like an empty
522 * handshake record
523 */
524 thisrr->type = SSL3_RT_HANDSHAKE;
525 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
526 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
527 > MAX_EMPTY_RECORDS) {
528 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
529 SSL_R_UNEXPECTED_CCS_MESSAGE);
530 return -1;
531 }
532 thisrr->read = 1;
533 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
534
535 return 1;
536 }
537
538 if (using_ktls)
539 goto skip_decryption;
540
541 /*
542 * If in encrypt-then-mac mode calculate mac from encrypted record. All
543 * the details below are public so no timing details can leak.
544 */
545 if (SSL_READ_ETM(s) && s->read_hash) {
546 unsigned char *mac;
547 /* TODO(size_t): convert this to do size_t properly */
548 imac_size = EVP_MD_CTX_size(s->read_hash);
549 if (!ossl_assert(imac_size >= 0 && imac_size <= EVP_MAX_MD_SIZE)) {
550 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
551 ERR_LIB_EVP);
552 return -1;
553 }
554 mac_size = (size_t)imac_size;
555 for (j = 0; j < num_recs; j++) {
556 thisrr = &rr[j];
557
558 if (thisrr->length < mac_size) {
559 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
560 SSL_R_LENGTH_TOO_SHORT);
561 return -1;
562 }
563 thisrr->length -= mac_size;
564 mac = thisrr->data + thisrr->length;
565 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
566 if (i == 0 || CRYPTO_memcmp(md, mac, mac_size) != 0) {
567 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
568 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
569 return -1;
570 }
571 }
572 }
573
574 first_rec_len = rr[0].length;
575
576 enc_err = s->method->ssl3_enc->enc(s, rr, num_recs, 0);
577
578 /*-
579 * enc_err is:
580 * 0: (in non-constant time) if the record is publicly invalid.
581 * 1: if the padding is valid
582 * -1: if the padding is invalid
583 */
584 if (enc_err == 0) {
585 if (ossl_statem_in_error(s)) {
586 /* SSLfatal() already got called */
587 return -1;
588 }
589 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
590 /*
591 * Valid early_data that we cannot decrypt might fail here as
592 * publicly invalid. We treat it like an empty record.
593 */
594
595 thisrr = &rr[0];
596
597 if (!early_data_count_ok(s, thisrr->length,
598 EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
599 /* SSLfatal() already called */
600 return -1;
601 }
602
603 thisrr->length = 0;
604 thisrr->read = 1;
605 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
606 RECORD_LAYER_reset_read_sequence(&s->rlayer);
607 return 1;
608 }
609 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
610 SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
611 return -1;
612 }
613 #ifdef SSL_DEBUG
614 printf("dec %lu\n", (unsigned long)rr[0].length);
615 {
616 size_t z;
617 for (z = 0; z < rr[0].length; z++)
618 printf("%02X%c", rr[0].data[z], ((z + 1) % 16) ? ' ' : '\n');
619 }
620 printf("\n");
621 #endif
622
623 /* r->length is now the compressed data plus mac */
624 if ((sess != NULL) &&
625 (s->enc_read_ctx != NULL) &&
626 (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL)) {
627 /* s->read_hash != NULL => mac_size != -1 */
628 unsigned char *mac = NULL;
629 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
630
631 mac_size = EVP_MD_CTX_size(s->read_hash);
632 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
633 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
634 ERR_R_INTERNAL_ERROR);
635 return -1;
636 }
637
638 for (j = 0; j < num_recs; j++) {
639 thisrr = &rr[j];
640 /*
641 * orig_len is the length of the record before any padding was
642 * removed. This is public information, as is the MAC in use,
643 * therefore we can safely process the record in a different amount
644 * of time if it's too short to possibly contain a MAC.
645 */
646 if (thisrr->orig_len < mac_size ||
647 /* CBC records must have a padding length byte too. */
648 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
649 thisrr->orig_len < mac_size + 1)) {
650 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_SSL3_GET_RECORD,
651 SSL_R_LENGTH_TOO_SHORT);
652 return -1;
653 }
654
655 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
656 /*
657 * We update the length so that the TLS header bytes can be
658 * constructed correctly but we need to extract the MAC in
659 * constant time from within the record, without leaking the
660 * contents of the padding bytes.
661 */
662 mac = mac_tmp;
663 if (!ssl3_cbc_copy_mac(mac_tmp, thisrr, mac_size)) {
664 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_GET_RECORD,
665 ERR_R_INTERNAL_ERROR);
666 return -1;
667 }
668 thisrr->length -= mac_size;
669 } else {
670 /*
671 * In this case there's no padding, so |rec->orig_len| equals
672 * |rec->length| and we checked that there's enough bytes for
673 * |mac_size| above.
674 */
675 thisrr->length -= mac_size;
676 mac = &thisrr->data[thisrr->length];
677 }
678
679 i = s->method->ssl3_enc->mac(s, thisrr, md, 0 /* not send */ );
680 if (i == 0 || mac == NULL
681 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
682 enc_err = -1;
683 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
684 enc_err = -1;
685 }
686 }
687
688 if (enc_err < 0) {
689 if (ossl_statem_in_error(s)) {
690 /* We already called SSLfatal() */
691 return -1;
692 }
693 if (num_recs == 1 && ossl_statem_skip_early_data(s)) {
694 /*
695 * We assume this is unreadable early_data - we treat it like an
696 * empty record
697 */
698
699 /*
700 * The record length may have been modified by the mac check above
701 * so we use the previously saved value
702 */
703 if (!early_data_count_ok(s, first_rec_len,
704 EARLY_DATA_CIPHERTEXT_OVERHEAD, 0)) {
705 /* SSLfatal() already called */
706 return -1;
707 }
708
709 thisrr = &rr[0];
710 thisrr->length = 0;
711 thisrr->read = 1;
712 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
713 RECORD_LAYER_reset_read_sequence(&s->rlayer);
714 return 1;
715 }
716 /*
717 * A separate 'decryption_failed' alert was introduced with TLS 1.0,
718 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
719 * failure is directly visible from the ciphertext anyway, we should
720 * not reveal which kind of error occurred -- this might become
721 * visible to an attacker (e.g. via a logfile)
722 */
723 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_SSL3_GET_RECORD,
724 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
725 return -1;
726 }
727
728 skip_decryption:
729
730 for (j = 0; j < num_recs; j++) {
731 thisrr = &rr[j];
732
733 /* thisrr->length is now just compressed */
734 if (s->expand != NULL) {
735 if (thisrr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
736 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
737 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
738 return -1;
739 }
740 if (!ssl3_do_uncompress(s, thisrr)) {
741 SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE, SSL_F_SSL3_GET_RECORD,
742 SSL_R_BAD_DECOMPRESSION);
743 return -1;
744 }
745 }
746
747 if (SSL_IS_TLS13(s)
748 && s->enc_read_ctx != NULL
749 && thisrr->type != SSL3_RT_ALERT) {
750 /*
751 * The following logic are irrelevant in KTLS: the kernel provides
752 * unprotected record and thus record type represent the actual
753 * content type, and padding is already removed and thisrr->type and
754 * thisrr->length should have the correct values.
755 */
756 if (!using_ktls) {
757 size_t end;
758
759 if (thisrr->length == 0
760 || thisrr->type != SSL3_RT_APPLICATION_DATA) {
761 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
762 SSL_F_SSL3_GET_RECORD, SSL_R_BAD_RECORD_TYPE);
763 return -1;
764 }
765
766 /* Strip trailing padding */
767 for (end = thisrr->length - 1; end > 0 && thisrr->data[end] == 0;
768 end--)
769 continue;
770
771 thisrr->length = end;
772 thisrr->type = thisrr->data[end];
773 }
774 if (thisrr->type != SSL3_RT_APPLICATION_DATA
775 && thisrr->type != SSL3_RT_ALERT
776 && thisrr->type != SSL3_RT_HANDSHAKE) {
777 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
778 SSL_R_BAD_RECORD_TYPE);
779 return -1;
780 }
781 if (s->msg_callback)
782 s->msg_callback(0, s->version, SSL3_RT_INNER_CONTENT_TYPE,
783 &thisrr->type, 1, s, s->msg_callback_arg);
784 }
785
786 /*
787 * TLSv1.3 alert and handshake records are required to be non-zero in
788 * length.
789 */
790 if (SSL_IS_TLS13(s)
791 && (thisrr->type == SSL3_RT_HANDSHAKE
792 || thisrr->type == SSL3_RT_ALERT)
793 && thisrr->length == 0) {
794 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
795 SSL_R_BAD_LENGTH);
796 return -1;
797 }
798
799 /*
800 * Usually thisrr->length is the length of a single record, but when
801 * KTLS handles the decryption, thisrr->length may be larger than
802 * SSL3_RT_MAX_PLAIN_LENGTH because the kernel may have coalesced
803 * multiple records.
804 * Therefore we have to rely on KTLS to check the plaintext length
805 * limit in the kernel.
806 */
807 if (thisrr->length > SSL3_RT_MAX_PLAIN_LENGTH && !using_ktls) {
808 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
809 SSL_R_DATA_LENGTH_TOO_LONG);
810 return -1;
811 }
812
813 /*
814 * Check if the received packet overflows the current
815 * Max Fragment Length setting.
816 * Note: USE_MAX_FRAGMENT_LENGTH_EXT and KTLS are mutually exclusive.
817 */
818 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
819 && thisrr->length > GET_MAX_FRAGMENT_LENGTH(s->session)) {
820 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_SSL3_GET_RECORD,
821 SSL_R_DATA_LENGTH_TOO_LONG);
822 return -1;
823 }
824
825 thisrr->off = 0;
826 /*-
827 * So at this point the following is true
828 * thisrr->type is the type of record
829 * thisrr->length == number of bytes in record
830 * thisrr->off == offset to first valid byte
831 * thisrr->data == where to take bytes from, increment after use :-).
832 */
833
834 /* just read a 0 length packet */
835 if (thisrr->length == 0) {
836 RECORD_LAYER_inc_empty_record_count(&s->rlayer);
837 if (RECORD_LAYER_get_empty_record_count(&s->rlayer)
838 > MAX_EMPTY_RECORDS) {
839 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_SSL3_GET_RECORD,
840 SSL_R_RECORD_TOO_SMALL);
841 return -1;
842 }
843 } else {
844 RECORD_LAYER_reset_empty_record_count(&s->rlayer);
845 }
846 }
847
848 if (s->early_data_state == SSL_EARLY_DATA_READING) {
849 thisrr = &rr[0];
850 if (thisrr->type == SSL3_RT_APPLICATION_DATA
851 && !early_data_count_ok(s, thisrr->length, 0, 0)) {
852 /* SSLfatal already called */
853 return -1;
854 }
855 }
856
857 RECORD_LAYER_set_numrpipes(&s->rlayer, num_recs);
858 return 1;
859 }
860
ssl3_do_uncompress(SSL * ssl,SSL3_RECORD * rr)861 int ssl3_do_uncompress(SSL *ssl, SSL3_RECORD *rr)
862 {
863 #ifndef OPENSSL_NO_COMP
864 int i;
865
866 if (rr->comp == NULL) {
867 rr->comp = (unsigned char *)
868 OPENSSL_malloc(SSL3_RT_MAX_ENCRYPTED_LENGTH);
869 }
870 if (rr->comp == NULL)
871 return 0;
872
873 /* TODO(size_t): Convert this call */
874 i = COMP_expand_block(ssl->expand, rr->comp,
875 SSL3_RT_MAX_PLAIN_LENGTH, rr->data, (int)rr->length);
876 if (i < 0)
877 return 0;
878 else
879 rr->length = i;
880 rr->data = rr->comp;
881 #endif
882 return 1;
883 }
884
ssl3_do_compress(SSL * ssl,SSL3_RECORD * wr)885 int ssl3_do_compress(SSL *ssl, SSL3_RECORD *wr)
886 {
887 #ifndef OPENSSL_NO_COMP
888 int i;
889
890 /* TODO(size_t): Convert this call */
891 i = COMP_compress_block(ssl->compress, wr->data,
892 (int)(wr->length + SSL3_RT_MAX_COMPRESSED_OVERHEAD),
893 wr->input, (int)wr->length);
894 if (i < 0)
895 return 0;
896 else
897 wr->length = i;
898
899 wr->input = wr->data;
900 #endif
901 return 1;
902 }
903
904 /*-
905 * ssl3_enc encrypts/decrypts |n_recs| records in |inrecs|. Will call
906 * SSLfatal() for internal errors, but not otherwise.
907 *
908 * Returns:
909 * 0: (in non-constant time) if the record is publicly invalid (i.e. too
910 * short etc).
911 * 1: if the record's padding is valid / the encryption was successful.
912 * -1: if the record's padding is invalid or, if sending, an internal error
913 * occurred.
914 */
ssl3_enc(SSL * s,SSL3_RECORD * inrecs,size_t n_recs,int sending)915 int ssl3_enc(SSL *s, SSL3_RECORD *inrecs, size_t n_recs, int sending)
916 {
917 SSL3_RECORD *rec;
918 EVP_CIPHER_CTX *ds;
919 size_t l, i;
920 size_t bs, mac_size = 0;
921 int imac_size;
922 const EVP_CIPHER *enc;
923
924 rec = inrecs;
925 /*
926 * We shouldn't ever be called with more than one record in the SSLv3 case
927 */
928 if (n_recs != 1)
929 return 0;
930 if (sending) {
931 ds = s->enc_write_ctx;
932 if (s->enc_write_ctx == NULL)
933 enc = NULL;
934 else
935 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
936 } else {
937 ds = s->enc_read_ctx;
938 if (s->enc_read_ctx == NULL)
939 enc = NULL;
940 else
941 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
942 }
943
944 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
945 memmove(rec->data, rec->input, rec->length);
946 rec->input = rec->data;
947 } else {
948 l = rec->length;
949 /* TODO(size_t): Convert this call */
950 bs = EVP_CIPHER_CTX_block_size(ds);
951
952 /* COMPRESS */
953
954 if ((bs != 1) && sending) {
955 i = bs - (l % bs);
956
957 /* we need to add 'i-1' padding bytes */
958 l += i;
959 /*
960 * the last of these zero bytes will be overwritten with the
961 * padding length.
962 */
963 memset(&rec->input[rec->length], 0, i);
964 rec->length += i;
965 rec->input[l - 1] = (unsigned char)(i - 1);
966 }
967
968 if (!sending) {
969 if (l == 0 || l % bs != 0)
970 return 0;
971 /* otherwise, rec->length >= bs */
972 }
973
974 /* TODO(size_t): Convert this call */
975 if (EVP_Cipher(ds, rec->data, rec->input, (unsigned int)l) < 1)
976 return -1;
977
978 if (EVP_MD_CTX_md(s->read_hash) != NULL) {
979 /* TODO(size_t): convert me */
980 imac_size = EVP_MD_CTX_size(s->read_hash);
981 if (imac_size < 0) {
982 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_ENC,
983 ERR_R_INTERNAL_ERROR);
984 return -1;
985 }
986 mac_size = (size_t)imac_size;
987 }
988 if ((bs != 1) && !sending)
989 return ssl3_cbc_remove_padding(rec, bs, mac_size);
990 }
991 return 1;
992 }
993
994 #define MAX_PADDING 256
995 /*-
996 * tls1_enc encrypts/decrypts |n_recs| in |recs|. Will call SSLfatal() for
997 * internal errors, but not otherwise.
998 *
999 * Returns:
1000 * 0: (in non-constant time) if the record is publicly invalid (i.e. too
1001 * short etc).
1002 * 1: if the record's padding is valid / the encryption was successful.
1003 * -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
1004 * an internal error occurred.
1005 */
tls1_enc(SSL * s,SSL3_RECORD * recs,size_t n_recs,int sending)1006 int tls1_enc(SSL *s, SSL3_RECORD *recs, size_t n_recs, int sending)
1007 {
1008 EVP_CIPHER_CTX *ds;
1009 size_t reclen[SSL_MAX_PIPELINES];
1010 unsigned char buf[SSL_MAX_PIPELINES][EVP_AEAD_TLS1_AAD_LEN];
1011 int i, pad = 0, ret, tmpr;
1012 size_t bs, mac_size = 0, ctr, padnum, loop;
1013 unsigned char padval;
1014 int imac_size;
1015 const EVP_CIPHER *enc;
1016
1017 if (n_recs == 0) {
1018 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1019 ERR_R_INTERNAL_ERROR);
1020 return 0;
1021 }
1022
1023 if (sending) {
1024 if (EVP_MD_CTX_md(s->write_hash)) {
1025 int n = EVP_MD_CTX_size(s->write_hash);
1026 if (!ossl_assert(n >= 0)) {
1027 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1028 ERR_R_INTERNAL_ERROR);
1029 return -1;
1030 }
1031 }
1032 ds = s->enc_write_ctx;
1033 if (s->enc_write_ctx == NULL)
1034 enc = NULL;
1035 else {
1036 int ivlen;
1037 enc = EVP_CIPHER_CTX_cipher(s->enc_write_ctx);
1038 /* For TLSv1.1 and later explicit IV */
1039 if (SSL_USE_EXPLICIT_IV(s)
1040 && EVP_CIPHER_mode(enc) == EVP_CIPH_CBC_MODE)
1041 ivlen = EVP_CIPHER_iv_length(enc);
1042 else
1043 ivlen = 0;
1044 if (ivlen > 1) {
1045 for (ctr = 0; ctr < n_recs; ctr++) {
1046 if (recs[ctr].data != recs[ctr].input) {
1047 /*
1048 * we can't write into the input stream: Can this ever
1049 * happen?? (steve)
1050 */
1051 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1052 ERR_R_INTERNAL_ERROR);
1053 return -1;
1054 } else if (RAND_bytes(recs[ctr].input, ivlen) <= 0) {
1055 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1056 ERR_R_INTERNAL_ERROR);
1057 return -1;
1058 }
1059 }
1060 }
1061 }
1062 } else {
1063 if (EVP_MD_CTX_md(s->read_hash)) {
1064 int n = EVP_MD_CTX_size(s->read_hash);
1065 if (!ossl_assert(n >= 0)) {
1066 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1067 ERR_R_INTERNAL_ERROR);
1068 return -1;
1069 }
1070 }
1071 ds = s->enc_read_ctx;
1072 if (s->enc_read_ctx == NULL)
1073 enc = NULL;
1074 else
1075 enc = EVP_CIPHER_CTX_cipher(s->enc_read_ctx);
1076 }
1077
1078 if ((s->session == NULL) || (ds == NULL) || (enc == NULL)) {
1079 for (ctr = 0; ctr < n_recs; ctr++) {
1080 memmove(recs[ctr].data, recs[ctr].input, recs[ctr].length);
1081 recs[ctr].input = recs[ctr].data;
1082 }
1083 ret = 1;
1084 } else {
1085 bs = EVP_CIPHER_block_size(EVP_CIPHER_CTX_cipher(ds));
1086
1087 if (n_recs > 1) {
1088 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1089 & EVP_CIPH_FLAG_PIPELINE)) {
1090 /*
1091 * We shouldn't have been called with pipeline data if the
1092 * cipher doesn't support pipelining
1093 */
1094 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1095 SSL_R_PIPELINE_FAILURE);
1096 return -1;
1097 }
1098 }
1099 for (ctr = 0; ctr < n_recs; ctr++) {
1100 reclen[ctr] = recs[ctr].length;
1101
1102 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1103 & EVP_CIPH_FLAG_AEAD_CIPHER) {
1104 unsigned char *seq;
1105
1106 seq = sending ? RECORD_LAYER_get_write_sequence(&s->rlayer)
1107 : RECORD_LAYER_get_read_sequence(&s->rlayer);
1108
1109 if (SSL_IS_DTLS(s)) {
1110 /* DTLS does not support pipelining */
1111 unsigned char dtlsseq[8], *p = dtlsseq;
1112
1113 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer) :
1114 DTLS_RECORD_LAYER_get_r_epoch(&s->rlayer), p);
1115 memcpy(p, &seq[2], 6);
1116 memcpy(buf[ctr], dtlsseq, 8);
1117 } else {
1118 memcpy(buf[ctr], seq, 8);
1119 for (i = 7; i >= 0; i--) { /* increment */
1120 ++seq[i];
1121 if (seq[i] != 0)
1122 break;
1123 }
1124 }
1125
1126 buf[ctr][8] = recs[ctr].type;
1127 buf[ctr][9] = (unsigned char)(s->version >> 8);
1128 buf[ctr][10] = (unsigned char)(s->version);
1129 buf[ctr][11] = (unsigned char)(recs[ctr].length >> 8);
1130 buf[ctr][12] = (unsigned char)(recs[ctr].length & 0xff);
1131 pad = EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_AEAD_TLS1_AAD,
1132 EVP_AEAD_TLS1_AAD_LEN, buf[ctr]);
1133 if (pad <= 0) {
1134 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1135 ERR_R_INTERNAL_ERROR);
1136 return -1;
1137 }
1138
1139 if (sending) {
1140 reclen[ctr] += pad;
1141 recs[ctr].length += pad;
1142 }
1143
1144 } else if ((bs != 1) && sending) {
1145 padnum = bs - (reclen[ctr] % bs);
1146
1147 /* Add weird padding of up to 256 bytes */
1148
1149 if (padnum > MAX_PADDING) {
1150 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1151 ERR_R_INTERNAL_ERROR);
1152 return -1;
1153 }
1154 /* we need to add 'padnum' padding bytes of value padval */
1155 padval = (unsigned char)(padnum - 1);
1156 for (loop = reclen[ctr]; loop < reclen[ctr] + padnum; loop++)
1157 recs[ctr].input[loop] = padval;
1158 reclen[ctr] += padnum;
1159 recs[ctr].length += padnum;
1160 }
1161
1162 if (!sending) {
1163 if (reclen[ctr] == 0 || reclen[ctr] % bs != 0)
1164 return 0;
1165 }
1166 }
1167 if (n_recs > 1) {
1168 unsigned char *data[SSL_MAX_PIPELINES];
1169
1170 /* Set the output buffers */
1171 for (ctr = 0; ctr < n_recs; ctr++) {
1172 data[ctr] = recs[ctr].data;
1173 }
1174 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_OUTPUT_BUFS,
1175 (int)n_recs, data) <= 0) {
1176 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1177 SSL_R_PIPELINE_FAILURE);
1178 return -1;
1179 }
1180 /* Set the input buffers */
1181 for (ctr = 0; ctr < n_recs; ctr++) {
1182 data[ctr] = recs[ctr].input;
1183 }
1184 if (EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_BUFS,
1185 (int)n_recs, data) <= 0
1186 || EVP_CIPHER_CTX_ctrl(ds, EVP_CTRL_SET_PIPELINE_INPUT_LENS,
1187 (int)n_recs, reclen) <= 0) {
1188 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1189 SSL_R_PIPELINE_FAILURE);
1190 return -1;
1191 }
1192 }
1193
1194 /* TODO(size_t): Convert this call */
1195 tmpr = EVP_Cipher(ds, recs[0].data, recs[0].input,
1196 (unsigned int)reclen[0]);
1197 if ((EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ds))
1198 & EVP_CIPH_FLAG_CUSTOM_CIPHER)
1199 ? (tmpr < 0)
1200 : (tmpr == 0))
1201 return -1; /* AEAD can fail to verify MAC */
1202
1203 if (sending == 0) {
1204 if (EVP_CIPHER_mode(enc) == EVP_CIPH_GCM_MODE) {
1205 for (ctr = 0; ctr < n_recs; ctr++) {
1206 recs[ctr].data += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1207 recs[ctr].input += EVP_GCM_TLS_EXPLICIT_IV_LEN;
1208 recs[ctr].length -= EVP_GCM_TLS_EXPLICIT_IV_LEN;
1209 }
1210 } else if (EVP_CIPHER_mode(enc) == EVP_CIPH_CCM_MODE) {
1211 for (ctr = 0; ctr < n_recs; ctr++) {
1212 recs[ctr].data += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1213 recs[ctr].input += EVP_CCM_TLS_EXPLICIT_IV_LEN;
1214 recs[ctr].length -= EVP_CCM_TLS_EXPLICIT_IV_LEN;
1215 }
1216 }
1217 }
1218
1219 ret = 1;
1220 if (!SSL_READ_ETM(s) && EVP_MD_CTX_md(s->read_hash) != NULL) {
1221 imac_size = EVP_MD_CTX_size(s->read_hash);
1222 if (imac_size < 0) {
1223 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS1_ENC,
1224 ERR_R_INTERNAL_ERROR);
1225 return -1;
1226 }
1227 mac_size = (size_t)imac_size;
1228 }
1229 if ((bs != 1) && !sending) {
1230 int tmpret;
1231 for (ctr = 0; ctr < n_recs; ctr++) {
1232 tmpret = tls1_cbc_remove_padding(s, &recs[ctr], bs, mac_size);
1233 /*
1234 * If tmpret == 0 then this means publicly invalid so we can
1235 * short circuit things here. Otherwise we must respect constant
1236 * time behaviour.
1237 */
1238 if (tmpret == 0)
1239 return 0;
1240 ret = constant_time_select_int(constant_time_eq_int(tmpret, 1),
1241 ret, -1);
1242 }
1243 }
1244 if (pad && !sending) {
1245 for (ctr = 0; ctr < n_recs; ctr++) {
1246 recs[ctr].length -= pad;
1247 }
1248 }
1249 }
1250 return ret;
1251 }
1252
n_ssl3_mac(SSL * ssl,SSL3_RECORD * rec,unsigned char * md,int sending)1253 int n_ssl3_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1254 {
1255 unsigned char *mac_sec, *seq;
1256 const EVP_MD_CTX *hash;
1257 unsigned char *p, rec_char;
1258 size_t md_size;
1259 size_t npad;
1260 int t;
1261
1262 if (sending) {
1263 mac_sec = &(ssl->s3->write_mac_secret[0]);
1264 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1265 hash = ssl->write_hash;
1266 } else {
1267 mac_sec = &(ssl->s3->read_mac_secret[0]);
1268 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1269 hash = ssl->read_hash;
1270 }
1271
1272 t = EVP_MD_CTX_size(hash);
1273 if (t < 0)
1274 return 0;
1275 md_size = t;
1276 npad = (48 / md_size) * md_size;
1277
1278 if (!sending &&
1279 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1280 ssl3_cbc_record_digest_supported(hash)) {
1281 /*
1282 * This is a CBC-encrypted record. We must avoid leaking any
1283 * timing-side channel information about how many blocks of data we
1284 * are hashing because that gives an attacker a timing-oracle.
1285 */
1286
1287 /*-
1288 * npad is, at most, 48 bytes and that's with MD5:
1289 * 16 + 48 + 8 (sequence bytes) + 1 + 2 = 75.
1290 *
1291 * With SHA-1 (the largest hash speced for SSLv3) the hash size
1292 * goes up 4, but npad goes down by 8, resulting in a smaller
1293 * total size.
1294 */
1295 unsigned char header[75];
1296 size_t j = 0;
1297 memcpy(header + j, mac_sec, md_size);
1298 j += md_size;
1299 memcpy(header + j, ssl3_pad_1, npad);
1300 j += npad;
1301 memcpy(header + j, seq, 8);
1302 j += 8;
1303 header[j++] = rec->type;
1304 header[j++] = (unsigned char)(rec->length >> 8);
1305 header[j++] = (unsigned char)(rec->length & 0xff);
1306
1307 /* Final param == is SSLv3 */
1308 if (ssl3_cbc_digest_record(hash,
1309 md, &md_size,
1310 header, rec->input,
1311 rec->length + md_size, rec->orig_len,
1312 mac_sec, md_size, 1) <= 0)
1313 return 0;
1314 } else {
1315 unsigned int md_size_u;
1316 /* Chop the digest off the end :-) */
1317 EVP_MD_CTX *md_ctx = EVP_MD_CTX_new();
1318
1319 if (md_ctx == NULL)
1320 return 0;
1321
1322 rec_char = rec->type;
1323 p = md;
1324 s2n(rec->length, p);
1325 if (EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1326 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1327 || EVP_DigestUpdate(md_ctx, ssl3_pad_1, npad) <= 0
1328 || EVP_DigestUpdate(md_ctx, seq, 8) <= 0
1329 || EVP_DigestUpdate(md_ctx, &rec_char, 1) <= 0
1330 || EVP_DigestUpdate(md_ctx, md, 2) <= 0
1331 || EVP_DigestUpdate(md_ctx, rec->input, rec->length) <= 0
1332 || EVP_DigestFinal_ex(md_ctx, md, NULL) <= 0
1333 || EVP_MD_CTX_copy_ex(md_ctx, hash) <= 0
1334 || EVP_DigestUpdate(md_ctx, mac_sec, md_size) <= 0
1335 || EVP_DigestUpdate(md_ctx, ssl3_pad_2, npad) <= 0
1336 || EVP_DigestUpdate(md_ctx, md, md_size) <= 0
1337 || EVP_DigestFinal_ex(md_ctx, md, &md_size_u) <= 0) {
1338 EVP_MD_CTX_free(md_ctx);
1339 return 0;
1340 }
1341
1342 EVP_MD_CTX_free(md_ctx);
1343 }
1344
1345 ssl3_record_sequence_update(seq);
1346 return 1;
1347 }
1348
tls1_mac(SSL * ssl,SSL3_RECORD * rec,unsigned char * md,int sending)1349 int tls1_mac(SSL *ssl, SSL3_RECORD *rec, unsigned char *md, int sending)
1350 {
1351 unsigned char *seq;
1352 EVP_MD_CTX *hash;
1353 size_t md_size;
1354 int i;
1355 EVP_MD_CTX *hmac = NULL, *mac_ctx;
1356 unsigned char header[13];
1357 int stream_mac = (sending ? (ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM)
1358 : (ssl->mac_flags & SSL_MAC_FLAG_READ_MAC_STREAM));
1359 int t;
1360
1361 if (sending) {
1362 seq = RECORD_LAYER_get_write_sequence(&ssl->rlayer);
1363 hash = ssl->write_hash;
1364 } else {
1365 seq = RECORD_LAYER_get_read_sequence(&ssl->rlayer);
1366 hash = ssl->read_hash;
1367 }
1368
1369 t = EVP_MD_CTX_size(hash);
1370 if (!ossl_assert(t >= 0))
1371 return 0;
1372 md_size = t;
1373
1374 /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
1375 if (stream_mac) {
1376 mac_ctx = hash;
1377 } else {
1378 hmac = EVP_MD_CTX_new();
1379 if (hmac == NULL || !EVP_MD_CTX_copy(hmac, hash)) {
1380 EVP_MD_CTX_free(hmac);
1381 return 0;
1382 }
1383 mac_ctx = hmac;
1384 }
1385
1386 if (SSL_IS_DTLS(ssl)) {
1387 unsigned char dtlsseq[8], *p = dtlsseq;
1388
1389 s2n(sending ? DTLS_RECORD_LAYER_get_w_epoch(&ssl->rlayer) :
1390 DTLS_RECORD_LAYER_get_r_epoch(&ssl->rlayer), p);
1391 memcpy(p, &seq[2], 6);
1392
1393 memcpy(header, dtlsseq, 8);
1394 } else
1395 memcpy(header, seq, 8);
1396
1397 header[8] = rec->type;
1398 header[9] = (unsigned char)(ssl->version >> 8);
1399 header[10] = (unsigned char)(ssl->version);
1400 header[11] = (unsigned char)(rec->length >> 8);
1401 header[12] = (unsigned char)(rec->length & 0xff);
1402
1403 if (!sending && !SSL_READ_ETM(ssl) &&
1404 EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1405 ssl3_cbc_record_digest_supported(mac_ctx)) {
1406 /*
1407 * This is a CBC-encrypted record. We must avoid leaking any
1408 * timing-side channel information about how many blocks of data we
1409 * are hashing because that gives an attacker a timing-oracle.
1410 */
1411 /* Final param == not SSLv3 */
1412 if (ssl3_cbc_digest_record(mac_ctx,
1413 md, &md_size,
1414 header, rec->input,
1415 rec->length + md_size, rec->orig_len,
1416 ssl->s3->read_mac_secret,
1417 ssl->s3->read_mac_secret_size, 0) <= 0) {
1418 EVP_MD_CTX_free(hmac);
1419 return 0;
1420 }
1421 } else {
1422 /* TODO(size_t): Convert these calls */
1423 if (EVP_DigestSignUpdate(mac_ctx, header, sizeof(header)) <= 0
1424 || EVP_DigestSignUpdate(mac_ctx, rec->input, rec->length) <= 0
1425 || EVP_DigestSignFinal(mac_ctx, md, &md_size) <= 0) {
1426 EVP_MD_CTX_free(hmac);
1427 return 0;
1428 }
1429 }
1430
1431 EVP_MD_CTX_free(hmac);
1432
1433 #ifdef SSL_DEBUG
1434 fprintf(stderr, "seq=");
1435 {
1436 int z;
1437 for (z = 0; z < 8; z++)
1438 fprintf(stderr, "%02X ", seq[z]);
1439 fprintf(stderr, "\n");
1440 }
1441 fprintf(stderr, "rec=");
1442 {
1443 size_t z;
1444 for (z = 0; z < rec->length; z++)
1445 fprintf(stderr, "%02X ", rec->data[z]);
1446 fprintf(stderr, "\n");
1447 }
1448 #endif
1449
1450 if (!SSL_IS_DTLS(ssl)) {
1451 for (i = 7; i >= 0; i--) {
1452 ++seq[i];
1453 if (seq[i] != 0)
1454 break;
1455 }
1456 }
1457 #ifdef SSL_DEBUG
1458 {
1459 unsigned int z;
1460 for (z = 0; z < md_size; z++)
1461 fprintf(stderr, "%02X ", md[z]);
1462 fprintf(stderr, "\n");
1463 }
1464 #endif
1465 return 1;
1466 }
1467
1468 /*-
1469 * ssl3_cbc_remove_padding removes padding from the decrypted, SSLv3, CBC
1470 * record in |rec| by updating |rec->length| in constant time.
1471 *
1472 * block_size: the block size of the cipher used to encrypt the record.
1473 * returns:
1474 * 0: (in non-constant time) if the record is publicly invalid.
1475 * 1: if the padding was valid
1476 * -1: otherwise.
1477 */
ssl3_cbc_remove_padding(SSL3_RECORD * rec,size_t block_size,size_t mac_size)1478 int ssl3_cbc_remove_padding(SSL3_RECORD *rec,
1479 size_t block_size, size_t mac_size)
1480 {
1481 size_t padding_length;
1482 size_t good;
1483 const size_t overhead = 1 /* padding length byte */ + mac_size;
1484
1485 /*
1486 * These lengths are all public so we can test them in non-constant time.
1487 */
1488 if (overhead > rec->length)
1489 return 0;
1490
1491 padding_length = rec->data[rec->length - 1];
1492 good = constant_time_ge_s(rec->length, padding_length + overhead);
1493 /* SSLv3 requires that the padding is minimal. */
1494 good &= constant_time_ge_s(block_size, padding_length + 1);
1495 rec->length -= good & (padding_length + 1);
1496 return constant_time_select_int_s(good, 1, -1);
1497 }
1498
1499 /*-
1500 * tls1_cbc_remove_padding removes the CBC padding from the decrypted, TLS, CBC
1501 * record in |rec| in constant time and returns 1 if the padding is valid and
1502 * -1 otherwise. It also removes any explicit IV from the start of the record
1503 * without leaking any timing about whether there was enough space after the
1504 * padding was removed.
1505 *
1506 * block_size: the block size of the cipher used to encrypt the record.
1507 * returns:
1508 * 0: (in non-constant time) if the record is publicly invalid.
1509 * 1: if the padding was valid
1510 * -1: otherwise.
1511 */
tls1_cbc_remove_padding(const SSL * s,SSL3_RECORD * rec,size_t block_size,size_t mac_size)1512 int tls1_cbc_remove_padding(const SSL *s,
1513 SSL3_RECORD *rec,
1514 size_t block_size, size_t mac_size)
1515 {
1516 size_t good;
1517 size_t padding_length, to_check, i;
1518 const size_t overhead = 1 /* padding length byte */ + mac_size;
1519 /* Check if version requires explicit IV */
1520 if (SSL_USE_EXPLICIT_IV(s)) {
1521 /*
1522 * These lengths are all public so we can test them in non-constant
1523 * time.
1524 */
1525 if (overhead + block_size > rec->length)
1526 return 0;
1527 /* We can now safely skip explicit IV */
1528 rec->data += block_size;
1529 rec->input += block_size;
1530 rec->length -= block_size;
1531 rec->orig_len -= block_size;
1532 } else if (overhead > rec->length)
1533 return 0;
1534
1535 padding_length = rec->data[rec->length - 1];
1536
1537 if (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_read_ctx)) &
1538 EVP_CIPH_FLAG_AEAD_CIPHER) {
1539 /* padding is already verified */
1540 rec->length -= padding_length + 1;
1541 return 1;
1542 }
1543
1544 good = constant_time_ge_s(rec->length, overhead + padding_length);
1545 /*
1546 * The padding consists of a length byte at the end of the record and
1547 * then that many bytes of padding, all with the same value as the length
1548 * byte. Thus, with the length byte included, there are i+1 bytes of
1549 * padding. We can't check just |padding_length+1| bytes because that
1550 * leaks decrypted information. Therefore we always have to check the
1551 * maximum amount of padding possible. (Again, the length of the record
1552 * is public information so we can use it.)
1553 */
1554 to_check = 256; /* maximum amount of padding, inc length byte. */
1555 if (to_check > rec->length)
1556 to_check = rec->length;
1557
1558 for (i = 0; i < to_check; i++) {
1559 unsigned char mask = constant_time_ge_8_s(padding_length, i);
1560 unsigned char b = rec->data[rec->length - 1 - i];
1561 /*
1562 * The final |padding_length+1| bytes should all have the value
1563 * |padding_length|. Therefore the XOR should be zero.
1564 */
1565 good &= ~(mask & (padding_length ^ b));
1566 }
1567
1568 /*
1569 * If any of the final |padding_length+1| bytes had the wrong value, one
1570 * or more of the lower eight bits of |good| will be cleared.
1571 */
1572 good = constant_time_eq_s(0xff, good & 0xff);
1573 rec->length -= good & (padding_length + 1);
1574
1575 return constant_time_select_int_s(good, 1, -1);
1576 }
1577
1578 /*-
1579 * ssl3_cbc_copy_mac copies |md_size| bytes from the end of |rec| to |out| in
1580 * constant time (independent of the concrete value of rec->length, which may
1581 * vary within a 256-byte window).
1582 *
1583 * ssl3_cbc_remove_padding or tls1_cbc_remove_padding must be called prior to
1584 * this function.
1585 *
1586 * On entry:
1587 * rec->orig_len >= md_size
1588 * md_size <= EVP_MAX_MD_SIZE
1589 *
1590 * If CBC_MAC_ROTATE_IN_PLACE is defined then the rotation is performed with
1591 * variable accesses in a 64-byte-aligned buffer. Assuming that this fits into
1592 * a single or pair of cache-lines, then the variable memory accesses don't
1593 * actually affect the timing. CPUs with smaller cache-lines [if any] are
1594 * not multi-core and are not considered vulnerable to cache-timing attacks.
1595 */
1596 #define CBC_MAC_ROTATE_IN_PLACE
1597
ssl3_cbc_copy_mac(unsigned char * out,const SSL3_RECORD * rec,size_t md_size)1598 int ssl3_cbc_copy_mac(unsigned char *out,
1599 const SSL3_RECORD *rec, size_t md_size)
1600 {
1601 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1602 unsigned char rotated_mac_buf[64 + EVP_MAX_MD_SIZE];
1603 unsigned char *rotated_mac;
1604 char aux1, aux2, aux3, mask;
1605 #else
1606 unsigned char rotated_mac[EVP_MAX_MD_SIZE];
1607 #endif
1608
1609 /*
1610 * mac_end is the index of |rec->data| just after the end of the MAC.
1611 */
1612 size_t mac_end = rec->length;
1613 size_t mac_start = mac_end - md_size;
1614 size_t in_mac;
1615 /*
1616 * scan_start contains the number of bytes that we can ignore because the
1617 * MAC's position can only vary by 255 bytes.
1618 */
1619 size_t scan_start = 0;
1620 size_t i, j;
1621 size_t rotate_offset;
1622
1623 if (!ossl_assert(rec->orig_len >= md_size
1624 && md_size <= EVP_MAX_MD_SIZE))
1625 return 0;
1626
1627 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1628 rotated_mac = rotated_mac_buf + ((0 - (size_t)rotated_mac_buf) & 63);
1629 #endif
1630
1631 /* This information is public so it's safe to branch based on it. */
1632 if (rec->orig_len > md_size + 255 + 1)
1633 scan_start = rec->orig_len - (md_size + 255 + 1);
1634
1635 in_mac = 0;
1636 rotate_offset = 0;
1637 memset(rotated_mac, 0, md_size);
1638 for (i = scan_start, j = 0; i < rec->orig_len; i++) {
1639 size_t mac_started = constant_time_eq_s(i, mac_start);
1640 size_t mac_ended = constant_time_lt_s(i, mac_end);
1641 unsigned char b = rec->data[i];
1642
1643 in_mac |= mac_started;
1644 in_mac &= mac_ended;
1645 rotate_offset |= j & mac_started;
1646 rotated_mac[j++] |= b & in_mac;
1647 j &= constant_time_lt_s(j, md_size);
1648 }
1649
1650 /* Now rotate the MAC */
1651 #if defined(CBC_MAC_ROTATE_IN_PLACE)
1652 j = 0;
1653 for (i = 0; i < md_size; i++) {
1654 /*
1655 * in case cache-line is 32 bytes,
1656 * load from both lines and select appropriately
1657 */
1658 aux1 = rotated_mac[rotate_offset & ~32];
1659 aux2 = rotated_mac[rotate_offset | 32];
1660 mask = constant_time_eq_8(rotate_offset & ~32, rotate_offset);
1661 aux3 = constant_time_select_8(mask, aux1, aux2);
1662 out[j++] = aux3;
1663 rotate_offset++;
1664 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1665 }
1666 #else
1667 memset(out, 0, md_size);
1668 rotate_offset = md_size - rotate_offset;
1669 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1670 for (i = 0; i < md_size; i++) {
1671 for (j = 0; j < md_size; j++)
1672 out[j] |= rotated_mac[i] & constant_time_eq_8_s(j, rotate_offset);
1673 rotate_offset++;
1674 rotate_offset &= constant_time_lt_s(rotate_offset, md_size);
1675 }
1676 #endif
1677
1678 return 1;
1679 }
1680
dtls1_process_record(SSL * s,DTLS1_BITMAP * bitmap)1681 int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
1682 {
1683 int i;
1684 int enc_err;
1685 SSL_SESSION *sess;
1686 SSL3_RECORD *rr;
1687 int imac_size;
1688 size_t mac_size;
1689 unsigned char md[EVP_MAX_MD_SIZE];
1690 size_t max_plain_length = SSL3_RT_MAX_PLAIN_LENGTH;
1691
1692 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1693 sess = s->session;
1694
1695 /*
1696 * At this point, s->rlayer.packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
1697 * and we have that many bytes in s->rlayer.packet
1698 */
1699 rr->input = &(RECORD_LAYER_get_packet(&s->rlayer)[DTLS1_RT_HEADER_LENGTH]);
1700
1701 /*
1702 * ok, we can now read from 's->rlayer.packet' data into 'rr'. rr->input
1703 * points at rr->length bytes, which need to be copied into rr->data by
1704 * either the decryption or by the decompression. When the data is 'copied'
1705 * into the rr->data buffer, rr->input will be pointed at the new buffer
1706 */
1707
1708 /*
1709 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
1710 * bytes of encrypted compressed stuff.
1711 */
1712
1713 /* check is not needed I believe */
1714 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
1715 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
1716 SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
1717 return 0;
1718 }
1719
1720 /* decrypt in place in 'rr->input' */
1721 rr->data = rr->input;
1722 rr->orig_len = rr->length;
1723
1724 if (SSL_READ_ETM(s) && s->read_hash) {
1725 unsigned char *mac;
1726 mac_size = EVP_MD_CTX_size(s->read_hash);
1727 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1728 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1729 ERR_R_INTERNAL_ERROR);
1730 return 0;
1731 }
1732 if (rr->orig_len < mac_size) {
1733 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1734 SSL_R_LENGTH_TOO_SHORT);
1735 return 0;
1736 }
1737 rr->length -= mac_size;
1738 mac = rr->data + rr->length;
1739 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1740 if (i == 0 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0) {
1741 SSLfatal(s, SSL_AD_BAD_RECORD_MAC, SSL_F_DTLS1_PROCESS_RECORD,
1742 SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
1743 return 0;
1744 }
1745 }
1746
1747 enc_err = s->method->ssl3_enc->enc(s, rr, 1, 0);
1748 /*-
1749 * enc_err is:
1750 * 0: (in non-constant time) if the record is publicly invalid.
1751 * 1: if the padding is valid
1752 * -1: if the padding is invalid
1753 */
1754 if (enc_err == 0) {
1755 if (ossl_statem_in_error(s)) {
1756 /* SSLfatal() got called */
1757 return 0;
1758 }
1759 /* For DTLS we simply ignore bad packets. */
1760 rr->length = 0;
1761 RECORD_LAYER_reset_packet_length(&s->rlayer);
1762 return 0;
1763 }
1764 #ifdef SSL_DEBUG
1765 printf("dec %ld\n", rr->length);
1766 {
1767 size_t z;
1768 for (z = 0; z < rr->length; z++)
1769 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
1770 }
1771 printf("\n");
1772 #endif
1773
1774 /* r->length is now the compressed data plus mac */
1775 if ((sess != NULL) && !SSL_READ_ETM(s) &&
1776 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
1777 /* s->read_hash != NULL => mac_size != -1 */
1778 unsigned char *mac = NULL;
1779 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
1780
1781 /* TODO(size_t): Convert this to do size_t properly */
1782 imac_size = EVP_MD_CTX_size(s->read_hash);
1783 if (imac_size < 0) {
1784 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1785 ERR_LIB_EVP);
1786 return 0;
1787 }
1788 mac_size = (size_t)imac_size;
1789 if (!ossl_assert(mac_size <= EVP_MAX_MD_SIZE)) {
1790 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1791 ERR_R_INTERNAL_ERROR);
1792 return 0;
1793 }
1794
1795 /*
1796 * orig_len is the length of the record before any padding was
1797 * removed. This is public information, as is the MAC in use,
1798 * therefore we can safely process the record in a different amount
1799 * of time if it's too short to possibly contain a MAC.
1800 */
1801 if (rr->orig_len < mac_size ||
1802 /* CBC records must have a padding length byte too. */
1803 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
1804 rr->orig_len < mac_size + 1)) {
1805 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1806 SSL_R_LENGTH_TOO_SHORT);
1807 return 0;
1808 }
1809
1810 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
1811 /*
1812 * We update the length so that the TLS header bytes can be
1813 * constructed correctly but we need to extract the MAC in
1814 * constant time from within the record, without leaking the
1815 * contents of the padding bytes.
1816 */
1817 mac = mac_tmp;
1818 if (!ssl3_cbc_copy_mac(mac_tmp, rr, mac_size)) {
1819 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_PROCESS_RECORD,
1820 ERR_R_INTERNAL_ERROR);
1821 return 0;
1822 }
1823 rr->length -= mac_size;
1824 } else {
1825 /*
1826 * In this case there's no padding, so |rec->orig_len| equals
1827 * |rec->length| and we checked that there's enough bytes for
1828 * |mac_size| above.
1829 */
1830 rr->length -= mac_size;
1831 mac = &rr->data[rr->length];
1832 }
1833
1834 i = s->method->ssl3_enc->mac(s, rr, md, 0 /* not send */ );
1835 if (i == 0 || mac == NULL
1836 || CRYPTO_memcmp(md, mac, mac_size) != 0)
1837 enc_err = -1;
1838 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
1839 enc_err = -1;
1840 }
1841
1842 if (enc_err < 0) {
1843 /* decryption failed, silently discard message */
1844 rr->length = 0;
1845 RECORD_LAYER_reset_packet_length(&s->rlayer);
1846 return 0;
1847 }
1848
1849 /* r->length is now just compressed */
1850 if (s->expand != NULL) {
1851 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
1852 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
1853 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
1854 return 0;
1855 }
1856 if (!ssl3_do_uncompress(s, rr)) {
1857 SSLfatal(s, SSL_AD_DECOMPRESSION_FAILURE,
1858 SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
1859 return 0;
1860 }
1861 }
1862
1863 /* use current Max Fragment Length setting if applicable */
1864 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session))
1865 max_plain_length = GET_MAX_FRAGMENT_LENGTH(s->session);
1866
1867 /* send overflow if the plaintext is too long now it has passed MAC */
1868 if (rr->length > max_plain_length) {
1869 SSLfatal(s, SSL_AD_RECORD_OVERFLOW, SSL_F_DTLS1_PROCESS_RECORD,
1870 SSL_R_DATA_LENGTH_TOO_LONG);
1871 return 0;
1872 }
1873
1874 rr->off = 0;
1875 /*-
1876 * So at this point the following is true
1877 * ssl->s3->rrec.type is the type of record
1878 * ssl->s3->rrec.length == number of bytes in record
1879 * ssl->s3->rrec.off == offset to first valid byte
1880 * ssl->s3->rrec.data == where to take bytes from, increment
1881 * after use :-).
1882 */
1883
1884 /* we have pulled in a full packet so zero things */
1885 RECORD_LAYER_reset_packet_length(&s->rlayer);
1886
1887 /* Mark receipt of record. */
1888 dtls1_record_bitmap_update(s, bitmap);
1889
1890 return 1;
1891 }
1892
1893 /*
1894 * Retrieve a buffered record that belongs to the current epoch, i.e. processed
1895 */
1896 #define dtls1_get_processed_record(s) \
1897 dtls1_retrieve_buffered_record((s), \
1898 &(DTLS_RECORD_LAYER_get_processed_rcds(&s->rlayer)))
1899
1900 /*-
1901 * Call this to get a new input record.
1902 * It will return <= 0 if more data is needed, normally due to an error
1903 * or non-blocking IO.
1904 * When it finishes, one packet has been decoded and can be found in
1905 * ssl->s3->rrec.type - is the type of record
1906 * ssl->s3->rrec.data, - data
1907 * ssl->s3->rrec.length, - number of bytes
1908 */
1909 /* used only by dtls1_read_bytes */
dtls1_get_record(SSL * s)1910 int dtls1_get_record(SSL *s)
1911 {
1912 int ssl_major, ssl_minor;
1913 int rret;
1914 size_t more, n;
1915 SSL3_RECORD *rr;
1916 unsigned char *p = NULL;
1917 unsigned short version;
1918 DTLS1_BITMAP *bitmap;
1919 unsigned int is_next_epoch;
1920
1921 rr = RECORD_LAYER_get_rrec(&s->rlayer);
1922
1923 again:
1924 /*
1925 * The epoch may have changed. If so, process all the pending records.
1926 * This is a non-blocking operation.
1927 */
1928 if (!dtls1_process_buffered_records(s)) {
1929 /* SSLfatal() already called */
1930 return -1;
1931 }
1932
1933 /* if we're renegotiating, then there may be buffered records */
1934 if (dtls1_get_processed_record(s))
1935 return 1;
1936
1937 /* get something from the wire */
1938
1939 /* check if we have the header */
1940 if ((RECORD_LAYER_get_rstate(&s->rlayer) != SSL_ST_READ_BODY) ||
1941 (RECORD_LAYER_get_packet_length(&s->rlayer) < DTLS1_RT_HEADER_LENGTH)) {
1942 rret = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH,
1943 SSL3_BUFFER_get_len(&s->rlayer.rbuf), 0, 1, &n);
1944 /* read timeout is handled by dtls1_read_bytes */
1945 if (rret <= 0) {
1946 /* SSLfatal() already called if appropriate */
1947 return rret; /* error or non-blocking */
1948 }
1949
1950 /* this packet contained a partial record, dump it */
1951 if (RECORD_LAYER_get_packet_length(&s->rlayer) !=
1952 DTLS1_RT_HEADER_LENGTH) {
1953 RECORD_LAYER_reset_packet_length(&s->rlayer);
1954 goto again;
1955 }
1956
1957 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_BODY);
1958
1959 p = RECORD_LAYER_get_packet(&s->rlayer);
1960
1961 if (s->msg_callback)
1962 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
1963 s, s->msg_callback_arg);
1964
1965 /* Pull apart the header into the DTLS1_RECORD */
1966 rr->type = *(p++);
1967 ssl_major = *(p++);
1968 ssl_minor = *(p++);
1969 version = (ssl_major << 8) | ssl_minor;
1970
1971 /* sequence number is 64 bits, with top 2 bytes = epoch */
1972 n2s(p, rr->epoch);
1973
1974 memcpy(&(RECORD_LAYER_get_read_sequence(&s->rlayer)[2]), p, 6);
1975 p += 6;
1976
1977 n2s(p, rr->length);
1978 rr->read = 0;
1979
1980 /*
1981 * Lets check the version. We tolerate alerts that don't have the exact
1982 * version number (e.g. because of protocol version errors)
1983 */
1984 if (!s->first_packet && rr->type != SSL3_RT_ALERT) {
1985 if (version != s->version) {
1986 /* unexpected version, silently discard */
1987 rr->length = 0;
1988 rr->read = 1;
1989 RECORD_LAYER_reset_packet_length(&s->rlayer);
1990 goto again;
1991 }
1992 }
1993
1994 if ((version & 0xff00) != (s->version & 0xff00)) {
1995 /* wrong version, silently discard record */
1996 rr->length = 0;
1997 rr->read = 1;
1998 RECORD_LAYER_reset_packet_length(&s->rlayer);
1999 goto again;
2000 }
2001
2002 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
2003 /* record too long, silently discard it */
2004 rr->length = 0;
2005 rr->read = 1;
2006 RECORD_LAYER_reset_packet_length(&s->rlayer);
2007 goto again;
2008 }
2009
2010 /* If received packet overflows own-client Max Fragment Length setting */
2011 if (s->session != NULL && USE_MAX_FRAGMENT_LENGTH_EXT(s->session)
2012 && rr->length > GET_MAX_FRAGMENT_LENGTH(s->session) + SSL3_RT_MAX_ENCRYPTED_OVERHEAD) {
2013 /* record too long, silently discard it */
2014 rr->length = 0;
2015 rr->read = 1;
2016 RECORD_LAYER_reset_packet_length(&s->rlayer);
2017 goto again;
2018 }
2019
2020 /* now s->rlayer.rstate == SSL_ST_READ_BODY */
2021 }
2022
2023 /* s->rlayer.rstate == SSL_ST_READ_BODY, get and decode the data */
2024
2025 if (rr->length >
2026 RECORD_LAYER_get_packet_length(&s->rlayer) - DTLS1_RT_HEADER_LENGTH) {
2027 /* now s->rlayer.packet_length == DTLS1_RT_HEADER_LENGTH */
2028 more = rr->length;
2029 rret = ssl3_read_n(s, more, more, 1, 1, &n);
2030 /* this packet contained a partial record, dump it */
2031 if (rret <= 0 || n != more) {
2032 if (ossl_statem_in_error(s)) {
2033 /* ssl3_read_n() called SSLfatal() */
2034 return -1;
2035 }
2036 rr->length = 0;
2037 rr->read = 1;
2038 RECORD_LAYER_reset_packet_length(&s->rlayer);
2039 goto again;
2040 }
2041
2042 /*
2043 * now n == rr->length, and s->rlayer.packet_length ==
2044 * DTLS1_RT_HEADER_LENGTH + rr->length
2045 */
2046 }
2047 /* set state for later operations */
2048 RECORD_LAYER_set_rstate(&s->rlayer, SSL_ST_READ_HEADER);
2049
2050 /* match epochs. NULL means the packet is dropped on the floor */
2051 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
2052 if (bitmap == NULL) {
2053 rr->length = 0;
2054 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
2055 goto again; /* get another record */
2056 }
2057 #ifndef OPENSSL_NO_SCTP
2058 /* Only do replay check if no SCTP bio */
2059 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
2060 #endif
2061 /* Check whether this is a repeat, or aged record. */
2062 /*
2063 * TODO: Does it make sense to have replay protection in epoch 0 where
2064 * we have no integrity negotiated yet?
2065 */
2066 if (!dtls1_record_replay_check(s, bitmap)) {
2067 rr->length = 0;
2068 rr->read = 1;
2069 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
2070 goto again; /* get another record */
2071 }
2072 #ifndef OPENSSL_NO_SCTP
2073 }
2074 #endif
2075
2076 /* just read a 0 length packet */
2077 if (rr->length == 0) {
2078 rr->read = 1;
2079 goto again;
2080 }
2081
2082 /*
2083 * If this record is from the next epoch (either HM or ALERT), and a
2084 * handshake is currently in progress, buffer it since it cannot be
2085 * processed at this time.
2086 */
2087 if (is_next_epoch) {
2088 if ((SSL_in_init(s) || ossl_statem_get_in_handshake(s))) {
2089 if (dtls1_buffer_record (s,
2090 &(DTLS_RECORD_LAYER_get_unprocessed_rcds(&s->rlayer)),
2091 rr->seq_num) < 0) {
2092 /* SSLfatal() already called */
2093 return -1;
2094 }
2095 }
2096 rr->length = 0;
2097 rr->read = 1;
2098 RECORD_LAYER_reset_packet_length(&s->rlayer);
2099 goto again;
2100 }
2101
2102 if (!dtls1_process_record(s, bitmap)) {
2103 if (ossl_statem_in_error(s)) {
2104 /* dtls1_process_record() called SSLfatal */
2105 return -1;
2106 }
2107 rr->length = 0;
2108 rr->read = 1;
2109 RECORD_LAYER_reset_packet_length(&s->rlayer); /* dump this record */
2110 goto again; /* get another record */
2111 }
2112
2113 return 1;
2114
2115 }
2116
dtls_buffer_listen_record(SSL * s,size_t len,unsigned char * seq,size_t off)2117 int dtls_buffer_listen_record(SSL *s, size_t len, unsigned char *seq, size_t off)
2118 {
2119 SSL3_RECORD *rr;
2120
2121 rr = RECORD_LAYER_get_rrec(&s->rlayer);
2122 memset(rr, 0, sizeof(SSL3_RECORD));
2123
2124 rr->length = len;
2125 rr->type = SSL3_RT_HANDSHAKE;
2126 memcpy(rr->seq_num, seq, sizeof(rr->seq_num));
2127 rr->off = off;
2128
2129 s->rlayer.packet = RECORD_LAYER_get_rbuf(&s->rlayer)->buf;
2130 s->rlayer.packet_length = DTLS1_RT_HEADER_LENGTH + len;
2131 rr->data = s->rlayer.packet + DTLS1_RT_HEADER_LENGTH;
2132
2133 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
2134 SSL3_RECORD_get_seq_num(s->rlayer.rrec)) <= 0) {
2135 /* SSLfatal() already called */
2136 return 0;
2137 }
2138
2139 return 1;
2140 }
2141