2 * Copyright 2005-2017 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include "../ssl_locl.h"
13 #include <openssl/evp.h>
14 #include <openssl/buffer.h>
15 #include "record_locl.h"
16 #include "../packet_locl.h"
17 #include "internal/cryptlib.h"
19 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
23 if ((d = OPENSSL_malloc(sizeof(*d))) == NULL)
28 d->unprocessed_rcds.q = pqueue_new();
29 d->processed_rcds.q = pqueue_new();
30 d->buffered_app_data.q = pqueue_new();
32 if (d->unprocessed_rcds.q == NULL || d->processed_rcds.q == NULL
33 || d->buffered_app_data.q == NULL) {
34 pqueue_free(d->unprocessed_rcds.q);
35 pqueue_free(d->processed_rcds.q);
36 pqueue_free(d->buffered_app_data.q);
45 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
47 DTLS_RECORD_LAYER_clear(rl);
48 pqueue_free(rl->d->unprocessed_rcds.q);
49 pqueue_free(rl->d->processed_rcds.q);
50 pqueue_free(rl->d->buffered_app_data.q);
55 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
59 DTLS1_RECORD_DATA *rdata;
60 pqueue *unprocessed_rcds;
61 pqueue *processed_rcds;
62 pqueue *buffered_app_data;
66 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) {
67 rdata = (DTLS1_RECORD_DATA *)item->data;
68 OPENSSL_free(rdata->rbuf.buf);
69 OPENSSL_free(item->data);
73 while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) {
74 rdata = (DTLS1_RECORD_DATA *)item->data;
75 OPENSSL_free(rdata->rbuf.buf);
76 OPENSSL_free(item->data);
80 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) {
81 rdata = (DTLS1_RECORD_DATA *)item->data;
82 OPENSSL_free(rdata->rbuf.buf);
83 OPENSSL_free(item->data);
87 unprocessed_rcds = d->unprocessed_rcds.q;
88 processed_rcds = d->processed_rcds.q;
89 buffered_app_data = d->buffered_app_data.q;
90 memset(d, 0, sizeof(*d));
91 d->unprocessed_rcds.q = unprocessed_rcds;
92 d->processed_rcds.q = processed_rcds;
93 d->buffered_app_data.q = buffered_app_data;
96 void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e)
98 if (e == rl->d->w_epoch - 1) {
99 memcpy(rl->d->curr_write_sequence,
100 rl->write_sequence, sizeof(rl->write_sequence));
101 memcpy(rl->write_sequence,
102 rl->d->last_write_sequence, sizeof(rl->write_sequence));
103 } else if (e == rl->d->w_epoch + 1) {
104 memcpy(rl->d->last_write_sequence,
105 rl->write_sequence, sizeof(unsigned char[8]));
106 memcpy(rl->write_sequence,
107 rl->d->curr_write_sequence, sizeof(rl->write_sequence));
112 void DTLS_RECORD_LAYER_set_write_sequence(RECORD_LAYER *rl, unsigned char *seq)
114 memcpy(rl->write_sequence, seq, SEQ_NUM_SIZE);
117 /* copy buffered record into SSL structure */
118 static int dtls1_copy_record(SSL *s, pitem *item)
120 DTLS1_RECORD_DATA *rdata;
122 rdata = (DTLS1_RECORD_DATA *)item->data;
124 SSL3_BUFFER_release(&s->rlayer.rbuf);
126 s->rlayer.packet = rdata->packet;
127 s->rlayer.packet_length = rdata->packet_length;
128 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
129 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
131 /* Set proper sequence number for mac calculation */
132 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
137 int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
139 DTLS1_RECORD_DATA *rdata;
142 /* Limit the size of the queue to prevent DOS attacks */
143 if (pqueue_size(queue->q) >= 100)
146 rdata = OPENSSL_malloc(sizeof(*rdata));
147 item = pitem_new(priority, rdata);
148 if (rdata == NULL || item == NULL) {
151 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
155 rdata->packet = s->rlayer.packet;
156 rdata->packet_length = s->rlayer.packet_length;
157 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
158 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
162 #ifndef OPENSSL_NO_SCTP
163 /* Store bio_dgram_sctp_rcvinfo struct */
164 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
165 (SSL_get_state(s) == TLS_ST_SR_FINISHED
166 || SSL_get_state(s) == TLS_ST_CR_FINISHED)) {
167 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
168 sizeof(rdata->recordinfo), &rdata->recordinfo);
172 s->rlayer.packet = NULL;
173 s->rlayer.packet_length = 0;
174 memset(&s->rlayer.rbuf, 0, sizeof(s->rlayer.rbuf));
175 memset(&s->rlayer.rrec, 0, sizeof(s->rlayer.rrec));
177 if (!ssl3_setup_buffers(s)) {
178 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
179 OPENSSL_free(rdata->rbuf.buf);
185 /* insert should not fail, since duplicates are dropped */
186 if (pqueue_insert(queue->q, item) == NULL) {
187 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
188 OPENSSL_free(rdata->rbuf.buf);
197 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
201 item = pqueue_pop(queue->q);
203 dtls1_copy_record(s, item);
205 OPENSSL_free(item->data);
215 * retrieve a buffered record that belongs to the new epoch, i.e., not
218 #define dtls1_get_unprocessed_record(s) \
219 dtls1_retrieve_buffered_record((s), \
220 &((s)->rlayer.d->unprocessed_rcds))
222 int dtls1_process_buffered_records(SSL *s)
227 DTLS1_BITMAP *bitmap;
228 unsigned int is_next_epoch;
231 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q);
233 /* Check if epoch is current. */
234 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch)
235 return 1; /* Nothing to do. */
237 rr = RECORD_LAYER_get_rrec(&s->rlayer);
239 rb = RECORD_LAYER_get_rbuf(&s->rlayer);
241 if (SSL3_BUFFER_get_left(rb) > 0) {
243 * We've still got data from the current packet to read. There could
244 * be a record from the new epoch in it - so don't overwrite it
245 * with the unprocessed records yet (we'll do it when we've
246 * finished reading the current packet).
251 /* Process all the records. */
252 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) {
253 dtls1_get_unprocessed_record(s);
254 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
255 if (bitmap == NULL) {
257 * Should not happen. This will only ever be NULL when the
258 * current record is from a different epoch. But that cannot
259 * be the case because we already checked the epoch above
261 SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
262 ERR_R_INTERNAL_ERROR);
265 #ifndef OPENSSL_NO_SCTP
266 /* Only do replay check if no SCTP bio */
267 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
271 * Check whether this is a repeat, or aged record. We did this
272 * check once already when we first received the record - but
273 * we might have updated the window since then due to
274 * records we subsequently processed.
276 replayok = dtls1_record_replay_check(s, bitmap);
279 if (!replayok || !dtls1_process_record(s, bitmap)) {
280 /* dump this record */
282 RECORD_LAYER_reset_packet_length(&s->rlayer);
286 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
287 SSL3_RECORD_get_seq_num(s->rlayer.rrec)) < 0)
293 * sync epoch numbers once all the unprocessed records have been
296 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch;
297 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1;
303 * Return up to 'len' payload bytes received in 'type' records.
304 * 'type' is one of the following:
306 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
307 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
308 * - 0 (during a shutdown, no data has to be returned)
310 * If we don't have stored data to work from, read a SSL/TLS record first
311 * (possibly multiple records if we still don't have anything to return).
313 * This function must handle any surprises the peer may have for us, such as
314 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec
315 * messages are treated as if they were handshake messages *if* the |recd_type|
316 * argument is non NULL.
317 * Also if record payloads contain fragments too small to process, we store
318 * them until there is enough for the respective protocol (the record protocol
319 * may use arbitrary fragmentation and even interleaving):
320 * Change cipher spec protocol
321 * just 1 byte needed, no need for keeping anything stored
323 * 2 bytes needed (AlertLevel, AlertDescription)
325 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
326 * to detect unexpected Client Hello and Hello Request messages
327 * here, anything else is handled by higher layers
328 * Application data protocol
329 * none of our business
331 int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
332 size_t len, int peek, size_t *readbytes)
337 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
339 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
340 /* Not initialized yet */
341 if (!ssl3_setup_buffers(s))
345 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
346 (type != SSL3_RT_HANDSHAKE)) ||
347 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
348 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
352 if (!ossl_statem_get_in_handshake(s) && SSL_in_init(s))
354 /* type == SSL3_RT_APPLICATION_DATA */
355 i = s->handshake_func(s);
359 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
365 s->rwstate = SSL_NOTHING;
368 * s->s3->rrec.type - is the type of record
369 * s->s3->rrec.data, - data
370 * s->s3->rrec.off, - offset into 'data' for next read
371 * s->s3->rrec.length, - number of bytes.
376 * We are not handshaking and have no data yet, so process data buffered
377 * during the last handshake in advance, if any.
379 if (SSL_is_init_finished(s) && SSL3_RECORD_get_length(rr) == 0) {
381 item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
383 #ifndef OPENSSL_NO_SCTP
384 /* Restore bio_dgram_sctp_rcvinfo struct */
385 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
386 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
387 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
388 sizeof(rdata->recordinfo), &rdata->recordinfo);
392 dtls1_copy_record(s, item);
394 OPENSSL_free(item->data);
399 /* Check for timeout */
400 if (dtls1_handle_timeout(s) > 0) {
402 } else if (ossl_statem_in_error(s)) {
403 /* dtls1_handle_timeout() has failed with a fatal error */
407 /* get new packet if necessary */
408 if ((SSL3_RECORD_get_length(rr) == 0)
409 || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
410 iret = dtls1_get_record(s);
412 iret = dtls1_read_failed(s, iret);
413 /* anything other than a timeout is an error */
422 * Reset the count of consecutive warning alerts if we've got a non-empty
423 * record that isn't an alert.
425 if (SSL3_RECORD_get_type(rr) != SSL3_RT_ALERT
426 && SSL3_RECORD_get_length(rr) != 0)
427 s->rlayer.alert_count = 0;
429 /* we now have a packet which can be read and processed */
431 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
432 * reset by ssl3_get_finished */
433 && (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) {
435 * We now have application data between CCS and Finished. Most likely
436 * the packets were reordered on their way, so buffer the application
437 * data for later processing rather than dropping the connection.
439 if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
440 SSL3_RECORD_get_seq_num(rr)) < 0) {
441 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
444 SSL3_RECORD_set_length(rr, 0);
449 * If the other end has shut down, throw anything we read away (even in
452 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
453 SSL3_RECORD_set_length(rr, 0);
454 s->rwstate = SSL_NOTHING;
458 if (type == SSL3_RECORD_get_type(rr)
459 || (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC
460 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
462 * SSL3_RT_APPLICATION_DATA or
463 * SSL3_RT_HANDSHAKE or
464 * SSL3_RT_CHANGE_CIPHER_SPEC
467 * make sure that we are not getting application data when we are
468 * doing a handshake for the first time
470 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
471 (s->enc_read_ctx == NULL)) {
472 al = SSL_AD_UNEXPECTED_MESSAGE;
473 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
477 if (recvd_type != NULL)
478 *recvd_type = SSL3_RECORD_get_type(rr);
483 if (len > SSL3_RECORD_get_length(rr))
484 n = SSL3_RECORD_get_length(rr);
488 memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
490 SSL3_RECORD_sub_length(rr, n);
491 SSL3_RECORD_add_off(rr, n);
492 if (SSL3_RECORD_get_length(rr) == 0) {
493 s->rlayer.rstate = SSL_ST_READ_HEADER;
494 SSL3_RECORD_set_off(rr, 0);
497 #ifndef OPENSSL_NO_SCTP
499 * We might had to delay a close_notify alert because of reordered
500 * app data. If there was an alert and there is no message to read
501 * anymore, finally set shutdown.
503 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
504 s->d1->shutdown_received
505 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
506 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
515 * If we get here, then type != rr->type; if we have a handshake message,
516 * then it was unexpected (Hello Request or Client Hello).
519 if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
520 unsigned int alert_level, alert_descr;
521 unsigned char *alert_bytes = SSL3_RECORD_get_data(rr)
522 + SSL3_RECORD_get_off(rr);
525 if (!PACKET_buf_init(&alert, alert_bytes, SSL3_RECORD_get_length(rr))
526 || !PACKET_get_1(&alert, &alert_level)
527 || !PACKET_get_1(&alert, &alert_descr)
528 || PACKET_remaining(&alert) != 0) {
529 al = SSL_AD_UNEXPECTED_MESSAGE;
530 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_INVALID_ALERT);
535 s->msg_callback(0, s->version, SSL3_RT_ALERT, alert_bytes, 2, s,
536 s->msg_callback_arg);
538 if (s->info_callback != NULL)
539 cb = s->info_callback;
540 else if (s->ctx->info_callback != NULL)
541 cb = s->ctx->info_callback;
544 j = (alert_level << 8) | alert_descr;
545 cb(s, SSL_CB_READ_ALERT, j);
548 if (alert_level == SSL3_AL_WARNING) {
549 s->s3->warn_alert = alert_descr;
551 s->rlayer.alert_count++;
552 if (s->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
553 al = SSL_AD_UNEXPECTED_MESSAGE;
554 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
558 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
559 #ifndef OPENSSL_NO_SCTP
561 * With SCTP and streams the socket may deliver app data
562 * after a close_notify alert. We have to check this first so
563 * that nothing gets discarded.
565 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
566 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
567 s->d1->shutdown_received = 1;
568 s->rwstate = SSL_READING;
569 BIO_clear_retry_flags(SSL_get_rbio(s));
570 BIO_set_retry_read(SSL_get_rbio(s));
574 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
577 } else if (alert_level == SSL3_AL_FATAL) {
580 s->rwstate = SSL_NOTHING;
581 s->s3->fatal_alert = alert_descr;
582 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
583 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
584 ERR_add_error_data(2, "SSL alert number ", tmp);
585 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
586 SSL_CTX_remove_session(s->session_ctx, s->session);
589 al = SSL_AD_ILLEGAL_PARAMETER;
590 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
597 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
599 s->rwstate = SSL_NOTHING;
600 SSL3_RECORD_set_length(rr, 0);
604 if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {
606 * We can't process a CCS now, because previous handshake messages
607 * are still missing, so just drop it.
609 SSL3_RECORD_set_length(rr, 0);
614 * Unexpected handshake message (Client Hello, or protocol violation)
616 if ((SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) &&
617 !ossl_statem_get_in_handshake(s)) {
618 struct hm_header_st msg_hdr;
621 * This may just be a stale retransmit. Also sanity check that we have
622 * at least enough record bytes for a message header
624 if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch
625 || SSL3_RECORD_get_length(rr) < DTLS1_HM_HEADER_LENGTH) {
626 SSL3_RECORD_set_length(rr, 0);
630 dtls1_get_message_header(rr->data, &msg_hdr);
633 * If we are server, we may have a repeated FINISHED of the client
634 * here, then retransmit our CCS and FINISHED.
636 if (msg_hdr.type == SSL3_MT_FINISHED) {
637 if (dtls1_check_timeout_num(s) < 0)
640 if (dtls1_retransmit_buffered_messages(s) <= 0) {
641 /* Fail if we encountered a fatal error */
642 if (ossl_statem_in_error(s))
645 SSL3_RECORD_set_length(rr, 0);
650 * To get here we must be trying to read app data but found handshake
651 * data. But if we're trying to read app data, and we're not in init
652 * (which is tested for at the top of this function) then init must be
655 if (!ossl_assert(SSL_is_init_finished(s))) {
656 al = SSL_AD_INTERNAL_ERROR;
657 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
661 /* We found handshake data, so we're going back into init */
662 ossl_statem_set_in_init(s, 1);
664 i = s->handshake_func(s);
668 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
672 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
673 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
674 /* no read-ahead left? */
677 * In the case where we try to read application data, but we
678 * trigger an SSL handshake, we return -1 with the retry
679 * option set. Otherwise renegotiation may cause nasty
680 * problems in the blocking world
682 s->rwstate = SSL_READING;
683 bio = SSL_get_rbio(s);
684 BIO_clear_retry_flags(bio);
685 BIO_set_retry_read(bio);
692 switch (SSL3_RECORD_get_type(rr)) {
694 al = SSL_AD_UNEXPECTED_MESSAGE;
695 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
697 case SSL3_RT_CHANGE_CIPHER_SPEC:
699 case SSL3_RT_HANDSHAKE:
701 * we already handled all of these, with the possible exception of
702 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
703 * that should not happen when type != rr->type
705 al = SSL_AD_UNEXPECTED_MESSAGE;
706 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
708 case SSL3_RT_APPLICATION_DATA:
710 * At this point, we were expecting handshake data, but have
711 * application data. If the library was running inside ssl3_read()
712 * (i.e. in_read_app_data is set) and it makes sense to read
713 * application data at this point (session renegotiation not yet
714 * started), we will indulge it.
716 if (s->s3->in_read_app_data &&
717 (s->s3->total_renegotiations != 0) &&
718 ossl_statem_app_data_allowed(s)) {
719 s->s3->in_read_app_data = 2;
722 al = SSL_AD_UNEXPECTED_MESSAGE;
723 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
730 ssl3_send_alert(s, SSL3_AL_FATAL, al);
735 * Call this to write data in records of type 'type' It will return <= 0 if
736 * not all data has been sent or non-blocking IO.
738 int dtls1_write_bytes(SSL *s, int type, const void *buf, size_t len,
743 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
744 SSLerr(SSL_F_DTLS1_WRITE_BYTES, ERR_R_INTERNAL_ERROR);
747 s->rwstate = SSL_NOTHING;
748 i = do_dtls1_write(s, type, buf, len, 0, written);
752 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
753 size_t len, int create_empty_fragment, size_t *written)
755 unsigned char *p, *pseq;
756 int i, mac_size, clear = 0;
757 size_t prefix_len = 0;
763 wb = &s->rlayer.wbuf[0];
766 * first check if there is a SSL3_BUFFER still being written out. This
767 * will happen with non blocking IO
769 if (!ossl_assert(SSL3_BUFFER_get_left(wb) == 0)) {
770 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
774 /* If we have an alert to send, lets send it */
775 if (s->s3->alert_dispatch) {
776 i = s->method->ssl_dispatch_alert(s);
779 /* if it went, fall through and send more stuff */
782 if (len == 0 && !create_empty_fragment)
785 if (len > ssl_get_max_send_fragment(s)) {
786 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
792 if ((sess == NULL) ||
793 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
799 mac_size = EVP_MD_CTX_size(s->write_hash);
804 p = SSL3_BUFFER_get_buf(wb) + prefix_len;
806 /* write the header */
808 *(p++) = type & 0xff;
809 SSL3_RECORD_set_type(&wr, type);
811 * Special case: for hello verify request, client version 1.0 and we
812 * haven't decided which version to use yet send back using version 1.0
813 * header: otherwise some clients will ignore it.
815 if (s->method->version == DTLS_ANY_VERSION &&
816 s->max_proto_version != DTLS1_BAD_VER) {
817 *(p++) = DTLS1_VERSION >> 8;
818 *(p++) = DTLS1_VERSION & 0xff;
820 *(p++) = s->version >> 8;
821 *(p++) = s->version & 0xff;
824 /* field where we are to write out packet epoch, seq num and len */
828 /* Explicit IV length, block ciphers appropriate version flag */
829 if (s->enc_write_ctx) {
830 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
831 if (mode == EVP_CIPH_CBC_MODE) {
832 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
836 /* Need explicit part of IV for GCM mode */
837 else if (mode == EVP_CIPH_GCM_MODE)
838 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
839 else if (mode == EVP_CIPH_CCM_MODE)
840 eivlen = EVP_CCM_TLS_EXPLICIT_IV_LEN;
846 /* lets setup the record stuff. */
847 SSL3_RECORD_set_data(&wr, p + eivlen); /* make room for IV in case of CBC */
848 SSL3_RECORD_set_length(&wr, len);
849 SSL3_RECORD_set_input(&wr, (unsigned char *)buf);
852 * we now 'read' from wr.input, wr.length bytes into wr.data
855 /* first we compress */
856 if (s->compress != NULL) {
857 if (!ssl3_do_compress(s, &wr)) {
858 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
862 memcpy(SSL3_RECORD_get_data(&wr), SSL3_RECORD_get_input(&wr),
863 SSL3_RECORD_get_length(&wr));
864 SSL3_RECORD_reset_input(&wr);
868 * we should still have the output to wr.data and the input from
869 * wr.input. Length should be wr.length. wr.data still points in the
873 if (!SSL_WRITE_ETM(s) && mac_size != 0) {
874 if (!s->method->ssl3_enc->mac(s, &wr,
875 &(p[SSL3_RECORD_get_length(&wr) + eivlen]),
878 SSL3_RECORD_add_length(&wr, mac_size);
881 /* this is true regardless of mac size */
882 SSL3_RECORD_set_data(&wr, p);
883 SSL3_RECORD_reset_input(&wr);
886 SSL3_RECORD_add_length(&wr, eivlen);
888 if (s->method->ssl3_enc->enc(s, &wr, 1, 1) < 1)
891 if (SSL_WRITE_ETM(s) && mac_size != 0) {
892 if (!s->method->ssl3_enc->mac(s, &wr,
893 &(p[SSL3_RECORD_get_length(&wr)]), 1))
895 SSL3_RECORD_add_length(&wr, mac_size);
898 /* record length after mac and block padding */
900 /* there's only one epoch between handshake and app data */
902 s2n(s->rlayer.d->w_epoch, pseq);
904 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
906 s2n(SSL3_RECORD_get_length(&wr), pseq);
909 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
910 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
913 * we should now have wr.data pointing to the encrypted data, which is
916 SSL3_RECORD_set_type(&wr, type); /* not needed but helps for debugging */
917 SSL3_RECORD_add_length(&wr, DTLS1_RT_HEADER_LENGTH);
919 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
921 if (create_empty_fragment) {
923 * we are in a recursive call; just return the length, don't write
926 *written = wr.length;
930 /* now let's set up wb */
931 SSL3_BUFFER_set_left(wb, prefix_len + SSL3_RECORD_get_length(&wr));
932 SSL3_BUFFER_set_offset(wb, 0);
935 * memorize arguments so that ssl3_write_pending can detect bad write
938 s->rlayer.wpend_tot = len;
939 s->rlayer.wpend_buf = buf;
940 s->rlayer.wpend_type = type;
941 s->rlayer.wpend_ret = len;
943 /* we now just need to write the buffer */
944 return ssl3_write_pending(s, type, buf, len, written);
949 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
950 unsigned int *is_next_epoch)
955 /* In current epoch, accept HM, CCS, DATA, & ALERT */
956 if (rr->epoch == s->rlayer.d->r_epoch)
957 return &s->rlayer.d->bitmap;
960 * Only HM and ALERT messages can be from the next epoch and only if we
961 * have already processed all of the unprocessed records from the last
964 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) &&
965 s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch &&
966 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
968 return &s->rlayer.d->next_bitmap;
974 void dtls1_reset_seq_numbers(SSL *s, int rw)
977 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
979 if (rw & SSL3_CC_READ) {
980 seq = s->rlayer.read_sequence;
981 s->rlayer.d->r_epoch++;
982 memcpy(&s->rlayer.d->bitmap, &s->rlayer.d->next_bitmap,
983 sizeof(s->rlayer.d->bitmap));
984 memset(&s->rlayer.d->next_bitmap, 0, sizeof(s->rlayer.d->next_bitmap));
987 * We must not use any buffered messages received from the previous
990 dtls1_clear_received_buffer(s);
992 seq = s->rlayer.write_sequence;
993 memcpy(s->rlayer.d->last_write_sequence, seq,
994 sizeof(s->rlayer.write_sequence));
995 s->rlayer.d->w_epoch++;
998 memset(seq, 0, seq_bytes);