1 /*
2 * Copyright 2005-2021 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 <stdio.h>
11 #include <errno.h>
12 #include "../ssl_local.h"
13 #include <openssl/evp.h>
14 #include <openssl/buffer.h>
15 #include "record_local.h"
16 #include "../packet_local.h"
17 #include "internal/cryptlib.h"
18
DTLS_RECORD_LAYER_new(RECORD_LAYER * rl)19 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
20 {
21 DTLS_RECORD_LAYER *d;
22
23 if ((d = OPENSSL_malloc(sizeof(*d))) == NULL) {
24 SSLerr(SSL_F_DTLS_RECORD_LAYER_NEW, ERR_R_MALLOC_FAILURE);
25 return 0;
26 }
27
28 rl->d = d;
29
30 d->unprocessed_rcds.q = pqueue_new();
31 d->processed_rcds.q = pqueue_new();
32 d->buffered_app_data.q = pqueue_new();
33
34 if (d->unprocessed_rcds.q == NULL || d->processed_rcds.q == NULL
35 || d->buffered_app_data.q == NULL) {
36 pqueue_free(d->unprocessed_rcds.q);
37 pqueue_free(d->processed_rcds.q);
38 pqueue_free(d->buffered_app_data.q);
39 OPENSSL_free(d);
40 rl->d = NULL;
41 return 0;
42 }
43
44 return 1;
45 }
46
DTLS_RECORD_LAYER_free(RECORD_LAYER * rl)47 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
48 {
49 if (rl->d == NULL)
50 return;
51
52 DTLS_RECORD_LAYER_clear(rl);
53 pqueue_free(rl->d->unprocessed_rcds.q);
54 pqueue_free(rl->d->processed_rcds.q);
55 pqueue_free(rl->d->buffered_app_data.q);
56 OPENSSL_free(rl->d);
57 rl->d = NULL;
58 }
59
DTLS_RECORD_LAYER_clear(RECORD_LAYER * rl)60 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
61 {
62 DTLS_RECORD_LAYER *d;
63 pitem *item = NULL;
64 DTLS1_RECORD_DATA *rdata;
65 pqueue *unprocessed_rcds;
66 pqueue *processed_rcds;
67 pqueue *buffered_app_data;
68
69 d = rl->d;
70
71 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) {
72 rdata = (DTLS1_RECORD_DATA *)item->data;
73 OPENSSL_free(rdata->rbuf.buf);
74 OPENSSL_free(item->data);
75 pitem_free(item);
76 }
77
78 while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) {
79 rdata = (DTLS1_RECORD_DATA *)item->data;
80 OPENSSL_free(rdata->rbuf.buf);
81 OPENSSL_free(item->data);
82 pitem_free(item);
83 }
84
85 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) {
86 rdata = (DTLS1_RECORD_DATA *)item->data;
87 OPENSSL_free(rdata->rbuf.buf);
88 OPENSSL_free(item->data);
89 pitem_free(item);
90 }
91
92 unprocessed_rcds = d->unprocessed_rcds.q;
93 processed_rcds = d->processed_rcds.q;
94 buffered_app_data = d->buffered_app_data.q;
95 memset(d, 0, sizeof(*d));
96 d->unprocessed_rcds.q = unprocessed_rcds;
97 d->processed_rcds.q = processed_rcds;
98 d->buffered_app_data.q = buffered_app_data;
99 }
100
DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER * rl,unsigned short e)101 void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e)
102 {
103 if (e == rl->d->w_epoch - 1) {
104 memcpy(rl->d->curr_write_sequence,
105 rl->write_sequence, sizeof(rl->write_sequence));
106 memcpy(rl->write_sequence,
107 rl->d->last_write_sequence, sizeof(rl->write_sequence));
108 } else if (e == rl->d->w_epoch + 1) {
109 memcpy(rl->d->last_write_sequence,
110 rl->write_sequence, sizeof(unsigned char[8]));
111 memcpy(rl->write_sequence,
112 rl->d->curr_write_sequence, sizeof(rl->write_sequence));
113 }
114 rl->d->w_epoch = e;
115 }
116
DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER * rl,unsigned char * seq)117 void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq)
118 {
119 memcpy(rl->write_sequence, seq, SEQ_NUM_SIZE);
120 }
121
122 /* copy buffered record into SSL structure */
dtls1_copy_record(SSL * s,pitem * item)123 static int dtls1_copy_record(SSL *s, pitem *item)
124 {
125 DTLS1_RECORD_DATA *rdata;
126
127 rdata = (DTLS1_RECORD_DATA *)item->data;
128
129 SSL3_BUFFER_release(&s->rlayer.rbuf);
130
131 s->rlayer.packet = rdata->packet;
132 s->rlayer.packet_length = rdata->packet_length;
133 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
134 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
135
136 /* Set proper sequence number for mac calculation */
137 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
138
139 return 1;
140 }
141
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)142 int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
143 {
144 DTLS1_RECORD_DATA *rdata;
145 pitem *item;
146
147 /* Limit the size of the queue to prevent DOS attacks */
148 if (pqueue_size(queue->q) >= 100)
149 return 0;
150
151 rdata = OPENSSL_malloc(sizeof(*rdata));
152 item = pitem_new(priority, rdata);
153 if (rdata == NULL || item == NULL) {
154 OPENSSL_free(rdata);
155 pitem_free(item);
156 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_BUFFER_RECORD,
157 ERR_R_INTERNAL_ERROR);
158 return -1;
159 }
160
161 rdata->packet = s->rlayer.packet;
162 rdata->packet_length = s->rlayer.packet_length;
163 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
164 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
165
166 item->data = rdata;
167
168 #ifndef OPENSSL_NO_SCTP
169 /* Store bio_dgram_sctp_rcvinfo struct */
170 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
171 (SSL_get_state(s) == TLS_ST_SR_FINISHED
172 || SSL_get_state(s) == TLS_ST_CR_FINISHED)) {
173 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
174 sizeof(rdata->recordinfo), &rdata->recordinfo);
175 }
176 #endif
177
178 s->rlayer.packet = NULL;
179 s->rlayer.packet_length = 0;
180 memset(&s->rlayer.rbuf, 0, sizeof(s->rlayer.rbuf));
181 memset(&s->rlayer.rrec, 0, sizeof(s->rlayer.rrec));
182
183 if (!ssl3_setup_buffers(s)) {
184 /* SSLfatal() already called */
185 OPENSSL_free(rdata->rbuf.buf);
186 OPENSSL_free(rdata);
187 pitem_free(item);
188 return -1;
189 }
190
191 if (pqueue_insert(queue->q, item) == NULL) {
192 /* Must be a duplicate so ignore it */
193 OPENSSL_free(rdata->rbuf.buf);
194 OPENSSL_free(rdata);
195 pitem_free(item);
196 }
197
198 return 1;
199 }
200
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)201 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
202 {
203 pitem *item;
204
205 item = pqueue_pop(queue->q);
206 if (item) {
207 dtls1_copy_record(s, item);
208
209 OPENSSL_free(item->data);
210 pitem_free(item);
211
212 return 1;
213 }
214
215 return 0;
216 }
217
218 /*
219 * retrieve a buffered record that belongs to the new epoch, i.e., not
220 * processed yet
221 */
222 #define dtls1_get_unprocessed_record(s) \
223 dtls1_retrieve_buffered_record((s), \
224 &((s)->rlayer.d->unprocessed_rcds))
225
dtls1_process_buffered_records(SSL * s)226 int dtls1_process_buffered_records(SSL *s)
227 {
228 pitem *item;
229 SSL3_BUFFER *rb;
230 SSL3_RECORD *rr;
231 DTLS1_BITMAP *bitmap;
232 unsigned int is_next_epoch;
233 int replayok = 1;
234
235 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q);
236 if (item) {
237 /* Check if epoch is current. */
238 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch)
239 return 1; /* Nothing to do. */
240
241 rr = RECORD_LAYER_get_rrec(&s->rlayer);
242
243 rb = RECORD_LAYER_get_rbuf(&s->rlayer);
244
245 if (SSL3_BUFFER_get_left(rb) > 0) {
246 /*
247 * We've still got data from the current packet to read. There could
248 * be a record from the new epoch in it - so don't overwrite it
249 * with the unprocessed records yet (we'll do it when we've
250 * finished reading the current packet).
251 */
252 return 1;
253 }
254
255 /* Process all the records. */
256 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) {
257 dtls1_get_unprocessed_record(s);
258 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
259 if (bitmap == NULL) {
260 /*
261 * Should not happen. This will only ever be NULL when the
262 * current record is from a different epoch. But that cannot
263 * be the case because we already checked the epoch above
264 */
265 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
266 SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
267 ERR_R_INTERNAL_ERROR);
268 return 0;
269 }
270 #ifndef OPENSSL_NO_SCTP
271 /* Only do replay check if no SCTP bio */
272 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
273 #endif
274 {
275 /*
276 * Check whether this is a repeat, or aged record. We did this
277 * check once already when we first received the record - but
278 * we might have updated the window since then due to
279 * records we subsequently processed.
280 */
281 replayok = dtls1_record_replay_check(s, bitmap);
282 }
283
284 if (!replayok || !dtls1_process_record(s, bitmap)) {
285 if (ossl_statem_in_error(s)) {
286 /* dtls1_process_record called SSLfatal() */
287 return -1;
288 }
289 /* dump this record */
290 rr->length = 0;
291 RECORD_LAYER_reset_packet_length(&s->rlayer);
292 continue;
293 }
294
295 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
296 SSL3_RECORD_get_seq_num(s->rlayer.rrec)) < 0) {
297 /* SSLfatal() already called */
298 return 0;
299 }
300 }
301 }
302
303 /*
304 * sync epoch numbers once all the unprocessed records have been
305 * processed
306 */
307 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch;
308 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1;
309
310 return 1;
311 }
312
313 /*-
314 * Return up to 'len' payload bytes received in 'type' records.
315 * 'type' is one of the following:
316 *
317 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
318 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
319 * - 0 (during a shutdown, no data has to be returned)
320 *
321 * If we don't have stored data to work from, read a SSL/TLS record first
322 * (possibly multiple records if we still don't have anything to return).
323 *
324 * This function must handle any surprises the peer may have for us, such as
325 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec
326 * messages are treated as if they were handshake messages *if* the |recd_type|
327 * argument is non NULL.
328 * Also if record payloads contain fragments too small to process, we store
329 * them until there is enough for the respective protocol (the record protocol
330 * may use arbitrary fragmentation and even interleaving):
331 * Change cipher spec protocol
332 * just 1 byte needed, no need for keeping anything stored
333 * Alert protocol
334 * 2 bytes needed (AlertLevel, AlertDescription)
335 * Handshake protocol
336 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
337 * to detect unexpected Client Hello and Hello Request messages
338 * here, anything else is handled by higher layers
339 * Application data protocol
340 * none of our business
341 */
dtls1_read_bytes(SSL * s,int type,int * recvd_type,unsigned char * buf,size_t len,int peek,size_t * readbytes)342 int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
343 size_t len, int peek, size_t *readbytes)
344 {
345 int i, j, iret;
346 size_t n;
347 SSL3_RECORD *rr;
348 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
349
350 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
351 /* Not initialized yet */
352 if (!ssl3_setup_buffers(s)) {
353 /* SSLfatal() already called */
354 return -1;
355 }
356 }
357
358 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
359 (type != SSL3_RT_HANDSHAKE)) ||
360 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
361 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES,
362 ERR_R_INTERNAL_ERROR);
363 return -1;
364 }
365
366 if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s)) {
367 /* type == SSL3_RT_APPLICATION_DATA */
368 i = s->handshake_func(s);
369 /* SSLfatal() already called if appropriate */
370 if (i < 0)
371 return i;
372 if (i == 0)
373 return -1;
374 }
375
376 start:
377 s->rwstate = SSL_NOTHING;
378
379 /*-
380 * s->s3->rrec.type - is the type of record
381 * s->s3->rrec.data, - data
382 * s->s3->rrec.off, - offset into 'data' for next read
383 * s->s3->rrec.length, - number of bytes.
384 */
385 rr = s->rlayer.rrec;
386
387 /*
388 * We are not handshaking and have no data yet, so process data buffered
389 * during the last handshake in advance, if any.
390 */
391 if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) {
392 pitem *item;
393 item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
394 if (item) {
395 #ifndef OPENSSL_NO_SCTP
396 /* Restore bio_dgram_sctp_rcvinfo struct */
397 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
398 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
399 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
400 sizeof(rdata->recordinfo), &rdata->recordinfo);
401 }
402 #endif
403
404 dtls1_copy_record(s, item);
405
406 OPENSSL_free(item->data);
407 pitem_free(item);
408 }
409 }
410
411 /* Check for timeout */
412 if (dtls1_handle_timeout(s) > 0) {
413 goto start;
414 } else if (ossl_statem_in_error(s)) {
415 /* dtls1_handle_timeout() has failed with a fatal error */
416 return -1;
417 }
418
419 /* get new packet if necessary */
420 if ((SSL3_RECORD_get_length(rr) == 0)
421 || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
422 RECORD_LAYER_set_numrpipes(&s->rlayer, 0);
423 iret = dtls1_get_record(s);
424 if (iret <= 0) {
425 iret = dtls1_read_failed(s, iret);
426 /*
427 * Anything other than a timeout is an error. SSLfatal() already
428 * called if appropriate.
429 */
430 if (iret <= 0)
431 return iret;
432 else
433 goto start;
434 }
435 RECORD_LAYER_set_numrpipes(&s->rlayer, 1);
436 }
437
438 /*
439 * Reset the count of consecutive warning alerts if we've got a non-empty
440 * record that isn't an alert.
441 */
442 if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT
443 && SSL3_RECORD_get_length(rr) != 0)
444 s->rlayer.alert_count = 0;
445
446 /* we now have a packet which can be read and processed */
447
448 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
449 * reset by ssl3_get_finished */
450 && (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) {
451 /*
452 * We now have application data between CCS and Finished. Most likely
453 * the packets were reordered on their way, so buffer the application
454 * data for later processing rather than dropping the connection.
455 */
456 if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
457 SSL3_RECORD_get_seq_num(rr)) < 0) {
458 /* SSLfatal() already called */
459 return -1;
460 }
461 SSL3_RECORD_set_length(rr, 0);
462 SSL3_RECORD_set_read(rr);
463 goto start;
464 }
465
466 /*
467 * If the other end has shut down, throw anything we read away (even in
468 * 'peek' mode)
469 */
470 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
471 SSL3_RECORD_set_length(rr, 0);
472 SSL3_RECORD_set_read(rr);
473 s->rwstate = SSL_NOTHING;
474 return 0;
475 }
476
477 if (type == SSL3_RECORD_get_type(rr)
478 || (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC
479 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
480 /*
481 * SSL3_RT_APPLICATION_DATA or
482 * SSL3_RT_HANDSHAKE or
483 * SSL3_RT_CHANGE_CIPHER_SPEC
484 */
485 /*
486 * make sure that we are not getting application data when we are
487 * doing a handshake for the first time
488 */
489 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
490 (s->enc_read_ctx == NULL)) {
491 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
492 SSL_R_APP_DATA_IN_HANDSHAKE);
493 return -1;
494 }
495
496 if (recvd_type != NULL)
497 *recvd_type = SSL3_RECORD_get_type(rr);
498
499 if (len == 0) {
500 /*
501 * Mark a zero length record as read. This ensures multiple calls to
502 * SSL_read() with a zero length buffer will eventually cause
503 * SSL_pending() to report data as being available.
504 */
505 if (SSL3_RECORD_get_length(rr) == 0)
506 SSL3_RECORD_set_read(rr);
507 return 0;
508 }
509
510 if (len > SSL3_RECORD_get_length(rr))
511 n = SSL3_RECORD_get_length(rr);
512 else
513 n = len;
514
515 memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
516 if (peek) {
517 if (SSL3_RECORD_get_length(rr) == 0)
518 SSL3_RECORD_set_read(rr);
519 } else {
520 SSL3_RECORD_sub_length(rr, n);
521 SSL3_RECORD_add_off(rr, n);
522 if (SSL3_RECORD_get_length(rr) == 0) {
523 s->rlayer.rstate = SSL_ST_READ_HEADER;
524 SSL3_RECORD_set_off(rr, 0);
525 SSL3_RECORD_set_read(rr);
526 }
527 }
528 #ifndef OPENSSL_NO_SCTP
529 /*
530 * We might had to delay a close_notify alert because of reordered
531 * app data. If there was an alert and there is no message to read
532 * anymore, finally set shutdown.
533 */
534 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
535 s->d1->shutdown_received
536 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
537 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
538 return 0;
539 }
540 #endif
541 *readbytes = n;
542 return 1;
543 }
544
545 /*
546 * If we get here, then type != rr->type; if we have a handshake message,
547 * then it was unexpected (Hello Request or Client Hello).
548 */
549
550 if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
551 unsigned int alert_level, alert_descr;
552 unsigned char *alert_bytes = SSL3_RECORD_get_data(rr)
553 + SSL3_RECORD_get_off(rr);
554 PACKET alert;
555
556 if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr))
557 || !PACKET_get_1(&alert, &alert_level)
558 || !PACKET_get_1(&alert, &alert_descr)
559 || PACKET_remaining(&alert) != 0) {
560 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
561 SSL_R_INVALID_ALERT);
562 return -1;
563 }
564
565 if (s->msg_callback)
566 s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 2, s,
567 s->msg_callback_arg);
568
569 if (s->info_callback != NULL)
570 cb = s->info_callback;
571 else if (s->ctx->info_callback != NULL)
572 cb = s->ctx->info_callback;
573
574 if (cb != NULL) {
575 j = (alert_level << 8) | alert_descr;
576 cb(s, SSL_CB_READ_ALERT, j);
577 }
578
579 if (alert_level == SSL3_AL_WARNING) {
580 s->s3->warn_alert = alert_descr;
581 SSL3_RECORD_set_read(rr);
582
583 s->rlayer.alert_count++;
584 if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
585 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
586 SSL_R_TOO_MANY_WARN_ALERTS);
587 return -1;
588 }
589
590 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
591 #ifndef OPENSSL_NO_SCTP
592 /*
593 * With SCTP and streams the socket may deliver app data
594 * after a close_notify alert. We have to check this first so
595 * that nothing gets discarded.
596 */
597 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
598 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
599 s->d1->shutdown_received = 1;
600 s->rwstate = SSL_READING;
601 BIO_clear_retry_flags(SSL_get_rbio(s));
602 BIO_set_retry_read(SSL_get_rbio(s));
603 return -1;
604 }
605 #endif
606 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
607 return 0;
608 }
609 } else if (alert_level == SSL3_AL_FATAL) {
610 char tmp[16];
611
612 s->rwstate = SSL_NOTHING;
613 s->s3->fatal_alert = alert_descr;
614 SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_DTLS1_READ_BYTES,
615 SSL_AD_REASON_OFFSET + alert_descr);
616 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
617 ERR_add_error_data(2, "SSL alert number ", tmp);
618 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
619 SSL3_RECORD_set_read(rr);
620 SSL_CTX_remove_session(s->session_ctx, s->session);
621 return 0;
622 } else {
623 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS1_READ_BYTES,
624 SSL_R_UNKNOWN_ALERT_TYPE);
625 return -1;
626 }
627
628 goto start;
629 }
630
631 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
632 * shutdown */
633 s->rwstate = SSL_NOTHING;
634 SSL3_RECORD_set_length(rr, 0);
635 SSL3_RECORD_set_read(rr);
636 return 0;
637 }
638
639 if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {
640 /*
641 * We can't process a CCS now, because previous handshake messages
642 * are still missing, so just drop it.
643 */
644 SSL3_RECORD_set_length(rr, 0);
645 SSL3_RECORD_set_read(rr);
646 goto start;
647 }
648
649 /*
650 * Unexpected handshake message (Client Hello, or protocol violation)
651 */
652 if ((SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) &&
653 !ossl_statem_get_in_handshake(s)) {
654 struct hm_header_st msg_hdr;
655
656 /*
657 * This may just be a stale retransmit. Also sanity check that we have
658 * at least enough record bytes for a message header
659 */
660 if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch
661 || SSL3_RECORD_get_length(rr) < DTLS1_HM_HEADER_LENGTH) {
662 SSL3_RECORD_set_length(rr, 0);
663 SSL3_RECORD_set_read(rr);
664 goto start;
665 }
666
667 dtls1_get_message_header(rr->data, &msg_hdr);
668
669 /*
670 * If we are server, we may have a repeated FINISHED of the client
671 * here, then retransmit our CCS and FINISHED.
672 */
673 if (msg_hdr.type == SSL3_MT_FINISHED) {
674 if (dtls1_check_timeout_num(s) < 0) {
675 /* SSLfatal) already called */
676 return -1;
677 }
678
679 if (dtls1_retransmit_buffered_messages(s) <= 0) {
680 /* Fail if we encountered a fatal error */
681 if (ossl_statem_in_error(s))
682 return -1;
683 }
684 SSL3_RECORD_set_length(rr, 0);
685 SSL3_RECORD_set_read(rr);
686 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
687 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
688 /* no read-ahead left? */
689 BIO *bio;
690
691 s->rwstate = SSL_READING;
692 bio = SSL_get_rbio(s);
693 BIO_clear_retry_flags(bio);
694 BIO_set_retry_read(bio);
695 return -1;
696 }
697 }
698 goto start;
699 }
700
701 /*
702 * To get here we must be trying to read app data but found handshake
703 * data. But if we're trying to read app data, and we're not in init
704 * (which is tested for at the top of this function) then init must be
705 * finished
706 */
707 if (!ossl_assert(SSL_is_init_finished(s))) {
708 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_READ_BYTES,
709 ERR_R_INTERNAL_ERROR);
710 return -1;
711 }
712
713 /* We found handshake data, so we're going back into init */
714 ossl_statem_set_in_init(s, 1);
715
716 i = s->handshake_func(s);
717 /* SSLfatal() called if appropriate */
718 if (i < 0)
719 return i;
720 if (i == 0)
721 return -1;
722
723 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
724 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
725 /* no read-ahead left? */
726 BIO *bio;
727 /*
728 * In the case where we try to read application data, but we
729 * trigger an SSL handshake, we return -1 with the retry
730 * option set. Otherwise renegotiation may cause nasty
731 * problems in the blocking world
732 */
733 s->rwstate = SSL_READING;
734 bio = SSL_get_rbio(s);
735 BIO_clear_retry_flags(bio);
736 BIO_set_retry_read(bio);
737 return -1;
738 }
739 }
740 goto start;
741 }
742
743 switch (SSL3_RECORD_get_type(rr)) {
744 default:
745 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
746 SSL_R_UNEXPECTED_RECORD);
747 return -1;
748 case SSL3_RT_CHANGE_CIPHER_SPEC:
749 case SSL3_RT_ALERT:
750 case SSL3_RT_HANDSHAKE:
751 /*
752 * we already handled all of these, with the possible exception of
753 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
754 * that should not happen when type != rr->type
755 */
756 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
757 ERR_R_INTERNAL_ERROR);
758 return -1;
759 case SSL3_RT_APPLICATION_DATA:
760 /*
761 * At this point, we were expecting handshake data, but have
762 * application data. If the library was running inside ssl3_read()
763 * (i.e. in_read_app_data is set) and it makes sense to read
764 * application data at this point (session renegotiation not yet
765 * started), we will indulge it.
766 */
767 if (s->s3->in_read_app_data &&
768 (s->s3->total_renegotiations != 0) &&
769 ossl_statem_app_data_allowed(s)) {
770 s->s3->in_read_app_data = 2;
771 return -1;
772 } else {
773 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_DTLS1_READ_BYTES,
774 SSL_R_UNEXPECTED_RECORD);
775 return -1;
776 }
777 }
778 /* not reached */
779 }
780
781 /*
782 * Call this to write data in records of type 'type' It will return <= 0 if
783 * not all data has been sent or non-blocking IO.
784 */
dtls1_write_bytes(SSL * s,int type,const void * buf,size_t len,size_t * written)785 int dtls1_write_bytes(SSL *s, int type, const void *buf, size_t len,
786 size_t *written)
787 {
788 int i;
789
790 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
791 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DTLS1_WRITE_BYTES,
792 ERR_R_INTERNAL_ERROR);
793 return -1;
794 }
795 s->rwstate = SSL_NOTHING;
796 i = do_dtls1_write(s, type, buf, len, 0, written);
797 return i;
798 }
799
do_dtls1_write(SSL * s,int type,const unsigned char * buf,size_t len,int create_empty_fragment,size_t * written)800 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
801 size_t len, int create_empty_fragment, size_t *written)
802 {
803 unsigned char *p, *pseq;
804 int i, mac_size, clear = 0;
805 size_t prefix_len = 0;
806 int eivlen;
807 SSL3_RECORD wr;
808 SSL3_BUFFER *wb;
809 SSL_SESSION *sess;
810
811 wb = &s->rlayer.wbuf[0];
812
813 /*
814 * DTLS writes whole datagrams, so there can't be anything left in
815 * the buffer.
816 */
817 if (!ossl_assert(SSL3_BUFFER_get_left(wb) == 0)) {
818 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
819 ERR_R_INTERNAL_ERROR);
820 return 0;
821 }
822
823 /* If we have an alert to send, lets send it */
824 if (s->s3->alert_dispatch) {
825 i = s->method->ssl_dispatch_alert(s);
826 if (i <= 0)
827 return i;
828 /* if it went, fall through and send more stuff */
829 }
830
831 if (len == 0 && !create_empty_fragment)
832 return 0;
833
834 if (len > ssl_get_max_send_fragment(s)) {
835 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
836 SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
837 return 0;
838 }
839
840 sess = s->session;
841
842 if ((sess == NULL) ||
843 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
844 clear = 1;
845
846 if (clear)
847 mac_size = 0;
848 else {
849 mac_size = EVP_MD_CTX_size(s->write_hash);
850 if (mac_size < 0) {
851 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
852 SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
853 return -1;
854 }
855 }
856
857 p = SSL3_BUFFER_get_buf(wb) + prefix_len;
858
859 /* write the header */
860
861 *(p++) = type & 0xff;
862 SSL3_RECORD_set_type(&wr, type);
863 /*
864 * Special case: for hello verify request, client version 1.0 and we
865 * haven't decided which version to use yet send back using version 1.0
866 * header: otherwise some clients will ignore it.
867 */
868 if (s->method->version == DTLS_ANY_VERSION &&
869 s->max_proto_version != DTLS1_BAD_VER) {
870 *(p++) = DTLS1_VERSION >> 8;
871 *(p++) = DTLS1_VERSION & 0xff;
872 } else {
873 *(p++) = s->version >> 8;
874 *(p++) = s->version & 0xff;
875 }
876
877 /* field where we are to write out packet epoch, seq num and len */
878 pseq = p;
879 p += 10;
880
881 /* Explicit IV length, block ciphers appropriate version flag */
882 if (s->enc_write_ctx) {
883 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
884 if (mode == EVP_CIPH_CBC_MODE) {
885 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
886 if (eivlen <= 1)
887 eivlen = 0;
888 }
889 /* Need explicit part of IV for GCM mode */
890 else if (mode == EVP_CIPH_GCM_MODE)
891 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
892 else if (mode == EVP_CIPH_CCM_MODE)
893 eivlen = EVP_CCM_TLS_EXPLICIT_IV_LEN;
894 else
895 eivlen = 0;
896 } else
897 eivlen = 0;
898
899 /* lets setup the record stuff. */
900 SSL3_RECORD_set_data(&wr, p + eivlen); /* make room for IV in case of CBC */
901 SSL3_RECORD_set_length(&wr, len);
902 SSL3_RECORD_set_input(&wr, (unsigned char *)buf);
903
904 /*
905 * we now 'read' from wr.input, wr.length bytes into wr.data
906 */
907
908 /* first we compress */
909 if (s->compress != NULL) {
910 if (!ssl3_do_compress(s, &wr)) {
911 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
912 SSL_R_COMPRESSION_FAILURE);
913 return -1;
914 }
915 } else {
916 memcpy(SSL3_RECORD_get_data(&wr), SSL3_RECORD_get_input(&wr),
917 SSL3_RECORD_get_length(&wr));
918 SSL3_RECORD_reset_input(&wr);
919 }
920
921 /*
922 * we should still have the output to wr.data and the input from
923 * wr.input. Length should be wr.length. wr.data still points in the
924 * wb->buf
925 */
926
927 if (!SSL_WRITE_ETM(s) && mac_size != 0) {
928 if (!s->method->ssl3_enc->mac(s, &wr,
929 &(p[SSL3_RECORD_get_length(&wr) + eivlen]),
930 1)) {
931 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
932 ERR_R_INTERNAL_ERROR);
933 return -1;
934 }
935 SSL3_RECORD_add_length(&wr, mac_size);
936 }
937
938 /* this is true regardless of mac size */
939 SSL3_RECORD_set_data(&wr, p);
940 SSL3_RECORD_reset_input(&wr);
941
942 if (eivlen)
943 SSL3_RECORD_add_length(&wr, eivlen);
944
945 if (s->method->ssl3_enc->enc(s, &wr, 1, 1) < 1) {
946 if (!ossl_statem_in_error(s)) {
947 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
948 ERR_R_INTERNAL_ERROR);
949 }
950 return -1;
951 }
952
953 if (SSL_WRITE_ETM(s) && mac_size != 0) {
954 if (!s->method->ssl3_enc->mac(s, &wr,
955 &(p[SSL3_RECORD_get_length(&wr)]), 1)) {
956 SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_DO_DTLS1_WRITE,
957 ERR_R_INTERNAL_ERROR);
958 return -1;
959 }
960 SSL3_RECORD_add_length(&wr, mac_size);
961 }
962
963 /* record length after mac and block padding */
964
965 /* there's only one epoch between handshake and app data */
966
967 s2n(s->rlayer.d->w_epoch, pseq);
968
969 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
970 pseq += 6;
971 s2n(SSL3_RECORD_get_length(&wr), pseq);
972
973 if (s->msg_callback)
974 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
975 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
976
977 /*
978 * we should now have wr.data pointing to the encrypted data, which is
979 * wr->length long
980 */
981 SSL3_RECORD_set_type(&wr, type); /* not needed but helps for debugging */
982 SSL3_RECORD_add_length(&wr, DTLS1_RT_HEADER_LENGTH);
983
984 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
985
986 if (create_empty_fragment) {
987 /*
988 * we are in a recursive call; just return the length, don't write
989 * out anything here
990 */
991 *written = wr.length;
992 return 1;
993 }
994
995 /* now let's set up wb */
996 SSL3_BUFFER_set_left(wb, prefix_len + SSL3_RECORD_get_length(&wr));
997 SSL3_BUFFER_set_offset(wb, 0);
998
999 /*
1000 * memorize arguments so that ssl3_write_pending can detect bad write
1001 * retries later
1002 */
1003 s->rlayer.wpend_tot = len;
1004 s->rlayer.wpend_buf = buf;
1005 s->rlayer.wpend_type = type;
1006 s->rlayer.wpend_ret = len;
1007
1008 /* we now just need to write the buffer. Calls SSLfatal() as required. */
1009 return ssl3_write_pending(s, type, buf, len, written);
1010 }
1011
dtls1_get_bitmap(SSL * s,SSL3_RECORD * rr,unsigned int * is_next_epoch)1012 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1013 unsigned int *is_next_epoch)
1014 {
1015
1016 *is_next_epoch = 0;
1017
1018 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1019 if (rr->epoch == s->rlayer.d->r_epoch)
1020 return &s->rlayer.d->bitmap;
1021
1022 /*
1023 * Only HM and ALERT messages can be from the next epoch and only if we
1024 * have already processed all of the unprocessed records from the last
1025 * epoch
1026 */
1027 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) &&
1028 s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch &&
1029 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1030 *is_next_epoch = 1;
1031 return &s->rlayer.d->next_bitmap;
1032 }
1033
1034 return NULL;
1035 }
1036
dtls1_reset_seq_numbers(SSL * s,int rw)1037 void dtls1_reset_seq_numbers(SSL *s, int rw)
1038 {
1039 unsigned char *seq;
1040 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
1041
1042 if (rw & SSL3_CC_READ) {
1043 seq = s->rlayer.read_sequence;
1044 s->rlayer.d->r_epoch++;
1045 memcpy(&s->rlayer.d->bitmap, &s->rlayer.d->next_bitmap,
1046 sizeof(s->rlayer.d->bitmap));
1047 memset(&s->rlayer.d->next_bitmap, 0, sizeof(s->rlayer.d->next_bitmap));
1048
1049 /*
1050 * We must not use any buffered messages received from the previous
1051 * epoch
1052 */
1053 dtls1_clear_received_buffer(s);
1054 } else {
1055 seq = s->rlayer.write_sequence;
1056 memcpy(s->rlayer.d->last_write_sequence, seq,
1057 sizeof(s->rlayer.write_sequence));
1058 s->rlayer.d->w_epoch++;
1059 }
1060
1061 memset(seq, 0, seq_bytes);
1062 }
1063