2 * Copyright 2005-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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_local.h"
13 #include <openssl/evp.h>
14 #include <openssl/buffer.h>
15 #include "record_local.h"
16 #include "internal/packet.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->buffered_app_data.q = pqueue_new();
30 if (d->buffered_app_data.q == NULL) {
39 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
44 DTLS_RECORD_LAYER_clear(rl);
45 pqueue_free(rl->d->buffered_app_data.q);
50 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
55 pqueue *buffered_app_data;
59 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) {
60 rec = (TLS_RECORD *)item->data;
61 if (rl->s->options & SSL_OP_CLEANSE_PLAINTEXT)
62 OPENSSL_cleanse(rec->data, rec->length);
63 OPENSSL_free(rec->data);
64 OPENSSL_free(item->data);
68 buffered_app_data = d->buffered_app_data.q;
69 memset(d, 0, sizeof(*d));
70 d->buffered_app_data.q = buffered_app_data;
73 static int dtls_buffer_record(SSL_CONNECTION *s, TLS_RECORD *rec)
77 record_pqueue *queue = &(s->rlayer.d->buffered_app_data);
79 /* Limit the size of the queue to prevent DOS attacks */
80 if (pqueue_size(queue->q) >= 100)
83 /* We don't buffer partially read records */
84 if (!ossl_assert(rec->off == 0))
87 rdata = OPENSSL_malloc(sizeof(*rdata));
88 item = pitem_new(rec->seq_num, rdata);
89 if (rdata == NULL || item == NULL) {
92 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
98 * We will release the record from the record layer soon, so we take a copy
99 * now. Copying data isn't good - but this should be infrequent so we
102 rdata->data = OPENSSL_memdup(rec->data, rec->length);
103 if (rdata->data == NULL) {
106 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_CRYPTO_LIB);
110 * We use a NULL rechandle to indicate that the data field has been
113 rdata->rechandle = NULL;
117 #ifndef OPENSSL_NO_SCTP
118 /* Store bio_dgram_sctp_rcvinfo struct */
119 if (BIO_dgram_is_sctp(s->rbio) &&
120 (ossl_statem_get_state(s) == TLS_ST_SR_FINISHED
121 || ossl_statem_get_state(s) == TLS_ST_CR_FINISHED)) {
122 BIO_ctrl(s->rbio, BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
123 sizeof(rdata->recordinfo), &rdata->recordinfo);
127 if (pqueue_insert(queue->q, item) == NULL) {
128 /* Must be a duplicate so ignore it */
129 OPENSSL_free(rdata->data);
137 /* Unbuffer a previously buffered TLS_RECORD structure if any */
138 static void dtls_unbuffer_record(SSL_CONNECTION *s)
143 /* If we already have records to handle then do nothing */
144 if (s->rlayer.curr_rec < s->rlayer.num_recs)
147 item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
149 rdata = (TLS_RECORD *)item->data;
151 s->rlayer.tlsrecs[0] = *rdata;
152 s->rlayer.num_recs = 1;
153 s->rlayer.curr_rec = 0;
155 #ifndef OPENSSL_NO_SCTP
156 /* Restore bio_dgram_sctp_rcvinfo struct */
157 if (BIO_dgram_is_sctp(s->rbio)) {
158 BIO_ctrl(s->rbio, BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
159 sizeof(rdata->recordinfo), &rdata->recordinfo);
163 OPENSSL_free(item->data);
169 * Return up to 'len' payload bytes received in 'type' records.
170 * 'type' is one of the following:
172 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
173 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
174 * - 0 (during a shutdown, no data has to be returned)
176 * If we don't have stored data to work from, read a SSL/TLS record first
177 * (possibly multiple records if we still don't have anything to return).
179 * This function must handle any surprises the peer may have for us, such as
180 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec
181 * messages are treated as if they were handshake messages *if* the |recd_type|
182 * argument is non NULL.
183 * Also if record payloads contain fragments too small to process, we store
184 * them until there is enough for the respective protocol (the record protocol
185 * may use arbitrary fragmentation and even interleaving):
186 * Change cipher spec protocol
187 * just 1 byte needed, no need for keeping anything stored
189 * 2 bytes needed (AlertLevel, AlertDescription)
191 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
192 * to detect unexpected Client Hello and Hello Request messages
193 * here, anything else is handled by higher layers
194 * Application data protocol
195 * none of our business
197 int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
198 size_t len, int peek, size_t *readbytes)
203 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
204 SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
209 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
210 (type != SSL3_RT_HANDSHAKE)) ||
211 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
212 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
216 if (!ossl_statem_get_in_handshake(sc) && SSL_in_init(s)) {
217 /* type == SSL3_RT_APPLICATION_DATA */
218 i = sc->handshake_func(s);
219 /* SSLfatal() already called if appropriate */
227 sc->rwstate = SSL_NOTHING;
230 * We are not handshaking and have no data yet, so process data buffered
231 * during the last handshake in advance, if any.
233 if (SSL_is_init_finished(s))
234 dtls_unbuffer_record(sc);
236 /* Check for timeout */
237 if (dtls1_handle_timeout(sc) > 0) {
239 } else if (ossl_statem_in_error(sc)) {
240 /* dtls1_handle_timeout() has failed with a fatal error */
244 /* get new packet if necessary */
245 if (sc->rlayer.curr_rec >= sc->rlayer.num_recs) {
246 sc->rlayer.curr_rec = sc->rlayer.num_recs = 0;
248 rr = &sc->rlayer.tlsrecs[sc->rlayer.num_recs];
250 ret = HANDLE_RLAYER_READ_RETURN(sc,
251 sc->rlayer.rrlmethod->read_record(sc->rlayer.rrl,
253 &rr->version, &rr->type,
254 &rr->data, &rr->length,
255 &rr->epoch, rr->seq_num));
257 ret = dtls1_read_failed(sc, ret);
259 * Anything other than a timeout is an error. SSLfatal() already
260 * called if appropriate.
268 sc->rlayer.num_recs++;
269 } while (sc->rlayer.rrlmethod->processed_read_pending(sc->rlayer.rrl)
270 && sc->rlayer.num_recs < SSL_MAX_PIPELINES);
272 rr = &sc->rlayer.tlsrecs[sc->rlayer.curr_rec];
275 * Reset the count of consecutive warning alerts if we've got a non-empty
276 * record that isn't an alert.
278 if (rr->type != SSL3_RT_ALERT && rr->length != 0)
279 sc->rlayer.alert_count = 0;
281 /* we now have a packet which can be read and processed */
283 if (sc->s3.change_cipher_spec /* set when we receive ChangeCipherSpec,
284 * reset by ssl3_get_finished */
285 && (rr->type != SSL3_RT_HANDSHAKE)) {
287 * We now have application data between CCS and Finished. Most likely
288 * the packets were reordered on their way, so buffer the application
289 * data for later processing rather than dropping the connection.
291 if (dtls_buffer_record(sc, rr) < 0) {
292 /* SSLfatal() already called */
295 ssl_release_record(sc, rr);
300 * If the other end has shut down, throw anything we read away (even in
303 if (sc->shutdown & SSL_RECEIVED_SHUTDOWN) {
304 ssl_release_record(sc, rr);
305 sc->rwstate = SSL_NOTHING;
310 || (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC
311 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
313 * SSL3_RT_APPLICATION_DATA or
314 * SSL3_RT_HANDSHAKE or
315 * SSL3_RT_CHANGE_CIPHER_SPEC
318 * make sure that we are not getting application data when we are
319 * doing a handshake for the first time
321 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA)
322 && (SSL_IS_FIRST_HANDSHAKE(sc))) {
323 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
324 SSL_R_APP_DATA_IN_HANDSHAKE);
328 if (recvd_type != NULL)
329 *recvd_type = rr->type;
333 * Release a zero length record. This ensures multiple calls to
334 * SSL_read() with a zero length buffer will eventually cause
335 * SSL_pending() to report data as being available.
338 ssl_release_record(sc, rr);
342 if (len > rr->length)
347 memcpy(buf, &(rr->data[rr->off]), n);
350 ssl_release_record(sc, rr);
352 if (sc->options & SSL_OP_CLEANSE_PLAINTEXT)
353 OPENSSL_cleanse(&(rr->data[rr->off]), n);
357 ssl_release_record(sc, rr);
359 #ifndef OPENSSL_NO_SCTP
361 * We might had to delay a close_notify alert because of reordered
362 * app data. If there was an alert and there is no message to read
363 * anymore, finally set shutdown.
365 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
366 sc->d1->shutdown_received
367 && BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) <= 0) {
368 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
377 * If we get here, then type != rr->type; if we have a handshake message,
378 * then it was unexpected (Hello Request or Client Hello).
381 if (rr->type == SSL3_RT_ALERT) {
382 unsigned int alert_level, alert_descr;
383 unsigned char *alert_bytes = rr->data + rr->off;
386 if (!PACKET_buf_init(&alert, alert_bytes, rr->length)
387 || !PACKET_get_1(&alert, &alert_level)
388 || !PACKET_get_1(&alert, &alert_descr)
389 || PACKET_remaining(&alert) != 0) {
390 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_INVALID_ALERT);
394 if (sc->msg_callback)
395 sc->msg_callback(0, sc->version, SSL3_RT_ALERT, alert_bytes, 2, s,
396 sc->msg_callback_arg);
398 if (sc->info_callback != NULL)
399 cb = sc->info_callback;
400 else if (s->ctx->info_callback != NULL)
401 cb = s->ctx->info_callback;
404 j = (alert_level << 8) | alert_descr;
405 cb(s, SSL_CB_READ_ALERT, j);
408 if (alert_level == SSL3_AL_WARNING) {
409 sc->s3.warn_alert = alert_descr;
410 ssl_release_record(sc, rr);
412 sc->rlayer.alert_count++;
413 if (sc->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
414 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
415 SSL_R_TOO_MANY_WARN_ALERTS);
419 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
420 #ifndef OPENSSL_NO_SCTP
422 * With SCTP and streams the socket may deliver app data
423 * after a close_notify alert. We have to check this first so
424 * that nothing gets discarded.
426 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
427 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) > 0) {
428 sc->d1->shutdown_received = 1;
429 sc->rwstate = SSL_READING;
430 BIO_clear_retry_flags(SSL_get_rbio(s));
431 BIO_set_retry_read(SSL_get_rbio(s));
435 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
438 } else if (alert_level == SSL3_AL_FATAL) {
439 sc->rwstate = SSL_NOTHING;
440 sc->s3.fatal_alert = alert_descr;
441 SSLfatal_data(sc, SSL_AD_NO_ALERT,
442 SSL_AD_REASON_OFFSET + alert_descr,
443 "SSL alert number %d", alert_descr);
444 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
445 ssl_release_record(sc, rr);
446 SSL_CTX_remove_session(sc->session_ctx, sc->session);
449 SSLfatal(sc, SSL_AD_ILLEGAL_PARAMETER, SSL_R_UNKNOWN_ALERT_TYPE);
456 if (sc->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
458 sc->rwstate = SSL_NOTHING;
459 ssl_release_record(sc, rr);
463 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
465 * We can't process a CCS now, because previous handshake messages
466 * are still missing, so just drop it.
468 ssl_release_record(sc, rr);
473 * Unexpected handshake message (Client Hello, or protocol violation)
475 if (rr->type == SSL3_RT_HANDSHAKE && !ossl_statem_get_in_handshake(sc)) {
476 struct hm_header_st msg_hdr;
479 * This may just be a stale retransmit. Also sanity check that we have
480 * at least enough record bytes for a message header
482 if (rr->epoch != sc->rlayer.d->r_epoch
483 || rr->length < DTLS1_HM_HEADER_LENGTH) {
484 ssl_release_record(sc, rr);
488 dtls1_get_message_header(rr->data, &msg_hdr);
491 * If we are server, we may have a repeated FINISHED of the client
492 * here, then retransmit our CCS and FINISHED.
494 if (msg_hdr.type == SSL3_MT_FINISHED) {
495 if (dtls1_check_timeout_num(sc) < 0) {
496 /* SSLfatal) already called */
500 if (dtls1_retransmit_buffered_messages(sc) <= 0) {
501 /* Fail if we encountered a fatal error */
502 if (ossl_statem_in_error(sc))
505 ssl_release_record(sc, rr);
506 if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
507 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
508 /* no read-ahead left? */
511 sc->rwstate = SSL_READING;
512 bio = SSL_get_rbio(s);
513 BIO_clear_retry_flags(bio);
514 BIO_set_retry_read(bio);
522 * To get here we must be trying to read app data but found handshake
523 * data. But if we're trying to read app data, and we're not in init
524 * (which is tested for at the top of this function) then init must be
527 if (!ossl_assert(SSL_is_init_finished(s))) {
528 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
532 /* We found handshake data, so we're going back into init */
533 ossl_statem_set_in_init(sc, 1);
535 i = sc->handshake_func(s);
536 /* SSLfatal() called if appropriate */
542 if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
543 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
544 /* no read-ahead left? */
547 * In the case where we try to read application data, but we
548 * trigger an SSL handshake, we return -1 with the retry
549 * option set. Otherwise renegotiation may cause nasty
550 * problems in the blocking world
552 sc->rwstate = SSL_READING;
553 bio = SSL_get_rbio(s);
554 BIO_clear_retry_flags(bio);
555 BIO_set_retry_read(bio);
564 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
566 case SSL3_RT_CHANGE_CIPHER_SPEC:
568 case SSL3_RT_HANDSHAKE:
570 * we already handled all of these, with the possible exception of
571 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
572 * that should not happen when type != rr->type
574 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, ERR_R_INTERNAL_ERROR);
576 case SSL3_RT_APPLICATION_DATA:
578 * At this point, we were expecting handshake data, but have
579 * application data. If the library was running inside ssl3_read()
580 * (i.e. in_read_app_data is set) and it makes sense to read
581 * application data at this point (session renegotiation not yet
582 * started), we will indulge it.
584 if (sc->s3.in_read_app_data &&
585 (sc->s3.total_renegotiations != 0) &&
586 ossl_statem_app_data_allowed(sc)) {
587 sc->s3.in_read_app_data = 2;
590 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
598 * Call this to write data in records of type 'type' It will return <= 0 if
599 * not all data has been sent or non-blocking IO.
601 int dtls1_write_bytes(SSL_CONNECTION *s, int type, const void *buf,
602 size_t len, size_t *written)
606 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
607 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
610 s->rwstate = SSL_NOTHING;
611 i = do_dtls1_write(s, type, buf, len, written);
615 int do_dtls1_write(SSL_CONNECTION *sc, int type, const unsigned char *buf,
616 size_t len, size_t *written)
619 OSSL_RECORD_TEMPLATE tmpl;
620 SSL *s = SSL_CONNECTION_GET_SSL(sc);
623 /* If we have an alert to send, lets send it */
624 if (sc->s3.alert_dispatch > 0) {
625 i = s->method->ssl_dispatch_alert(s);
628 /* if it went, fall through and send more stuff */
634 if (len > ssl_get_max_send_fragment(sc)) {
635 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
641 * Special case: for hello verify request, client version 1.0 and we
642 * haven't decided which version to use yet send back using version 1.0
643 * header: otherwise some clients will ignore it.
645 if (s->method->version == DTLS_ANY_VERSION
646 && sc->max_proto_version != DTLS1_BAD_VER)
647 tmpl.version = DTLS1_VERSION;
649 tmpl.version = sc->version;
653 ret = HANDLE_RLAYER_WRITE_RETURN(sc,
654 sc->rlayer.wrlmethod->write_records(sc->rlayer.wrl, &tmpl, 1));
662 void dtls1_increment_epoch(SSL_CONNECTION *s, int rw)
664 if (rw & SSL3_CC_READ) {
665 s->rlayer.d->r_epoch++;
668 * We must not use any buffered messages received from the previous
671 dtls1_clear_received_buffer(s);
673 s->rlayer.d->w_epoch++;