2 * Copyright 2005-2023 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 = pqueue_new();
30 if (d->buffered_app_data == NULL) {
39 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
44 DTLS_RECORD_LAYER_clear(rl);
45 pqueue_free(rl->d->buffered_app_data);
50 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
55 pqueue *buffered_app_data;
59 while ((item = pqueue_pop(d->buffered_app_data)) != NULL) {
60 rec = (TLS_RECORD *)item->data;
62 if (rl->s->options & SSL_OP_CLEANSE_PLAINTEXT)
63 OPENSSL_cleanse(rec->allocdata, rec->length);
64 OPENSSL_free(rec->allocdata);
65 OPENSSL_free(item->data);
69 buffered_app_data = d->buffered_app_data;
70 memset(d, 0, sizeof(*d));
71 d->buffered_app_data = buffered_app_data;
74 static int dtls_buffer_record(SSL_CONNECTION *s, TLS_RECORD *rec)
78 struct pqueue_st *queue = s->rlayer.d->buffered_app_data;
80 /* Limit the size of the queue to prevent DOS attacks */
81 if (pqueue_size(queue) >= 100)
84 /* We don't buffer partially read records */
85 if (!ossl_assert(rec->off == 0))
88 rdata = OPENSSL_malloc(sizeof(*rdata));
89 item = pitem_new(rec->seq_num, rdata);
90 if (rdata == NULL || item == NULL) {
93 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
99 * We will release the record from the record layer soon, so we take a copy
100 * now. Copying data isn't good - but this should be infrequent so we
103 rdata->data = rdata->allocdata = OPENSSL_memdup(rec->data, rec->length);
104 if (rdata->data == NULL) {
107 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_CRYPTO_LIB);
111 * We use a NULL rechandle to indicate that the data field has been
114 rdata->rechandle = NULL;
118 #ifndef OPENSSL_NO_SCTP
119 /* Store bio_dgram_sctp_rcvinfo struct */
120 if (BIO_dgram_is_sctp(s->rbio) &&
121 (ossl_statem_get_state(s) == TLS_ST_SR_FINISHED
122 || ossl_statem_get_state(s) == TLS_ST_CR_FINISHED)) {
123 BIO_ctrl(s->rbio, BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
124 sizeof(rdata->recordinfo), &rdata->recordinfo);
128 if (pqueue_insert(queue, item) == NULL) {
129 /* Must be a duplicate so ignore it */
130 OPENSSL_free(rdata->allocdata);
138 /* Unbuffer a previously buffered TLS_RECORD structure if any */
139 static void dtls_unbuffer_record(SSL_CONNECTION *s)
144 /* If we already have records to handle then do nothing */
145 if (s->rlayer.curr_rec < s->rlayer.num_recs)
148 item = pqueue_pop(s->rlayer.d->buffered_app_data);
150 rdata = (TLS_RECORD *)item->data;
152 s->rlayer.tlsrecs[0] = *rdata;
153 s->rlayer.num_recs = 1;
154 s->rlayer.curr_rec = 0;
156 #ifndef OPENSSL_NO_SCTP
157 /* Restore bio_dgram_sctp_rcvinfo struct */
158 if (BIO_dgram_is_sctp(s->rbio)) {
159 BIO_ctrl(s->rbio, BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
160 sizeof(rdata->recordinfo), &rdata->recordinfo);
164 OPENSSL_free(item->data);
170 * Return up to 'len' payload bytes received in 'type' records.
171 * 'type' is one of the following:
173 * - SSL3_RT_HANDSHAKE
174 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
175 * - 0 (during a shutdown, no data has to be returned)
177 * If we don't have stored data to work from, read a SSL/TLS record first
178 * (possibly multiple records if we still don't have anything to return).
180 * This function must handle any surprises the peer may have for us, such as
181 * Alert records (e.g. close_notify) or renegotiation requests. ChangeCipherSpec
182 * messages are treated as if they were handshake messages *if* the |recd_type|
183 * argument is non NULL.
184 * Also if record payloads contain fragments too small to process, we store
185 * them until there is enough for the respective protocol (the record protocol
186 * may use arbitrary fragmentation and even interleaving):
187 * Change cipher spec protocol
188 * just 1 byte needed, no need for keeping anything stored
190 * 2 bytes needed (AlertLevel, AlertDescription)
192 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
193 * to detect unexpected Client Hello and Hello Request messages
194 * here, anything else is handled by higher layers
195 * Application data protocol
196 * none of our business
198 int dtls1_read_bytes(SSL *s, uint8_t type, uint8_t *recvd_type,
199 unsigned char *buf, size_t len,
200 int peek, size_t *readbytes)
205 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
206 SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
211 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
212 (type != SSL3_RT_HANDSHAKE)) ||
213 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
214 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
218 if (!ossl_statem_get_in_handshake(sc) && SSL_in_init(s)) {
219 /* type == SSL3_RT_APPLICATION_DATA */
220 i = sc->handshake_func(s);
221 /* SSLfatal() already called if appropriate */
229 sc->rwstate = SSL_NOTHING;
232 * We are not handshaking and have no data yet, so process data buffered
233 * during the last handshake in advance, if any.
235 if (SSL_is_init_finished(s))
236 dtls_unbuffer_record(sc);
238 /* Check for timeout */
239 if (dtls1_handle_timeout(sc) > 0) {
241 } else if (ossl_statem_in_error(sc)) {
242 /* dtls1_handle_timeout() has failed with a fatal error */
246 /* get new packet if necessary */
247 if (sc->rlayer.curr_rec >= sc->rlayer.num_recs) {
248 sc->rlayer.curr_rec = sc->rlayer.num_recs = 0;
250 rr = &sc->rlayer.tlsrecs[sc->rlayer.num_recs];
252 ret = HANDLE_RLAYER_READ_RETURN(sc,
253 sc->rlayer.rrlmethod->read_record(sc->rlayer.rrl,
255 &rr->version, &rr->type,
256 &rr->data, &rr->length,
257 &rr->epoch, rr->seq_num));
259 ret = dtls1_read_failed(sc, ret);
261 * Anything other than a timeout is an error. SSLfatal() already
262 * called if appropriate.
270 sc->rlayer.num_recs++;
271 } while (sc->rlayer.rrlmethod->processed_read_pending(sc->rlayer.rrl)
272 && sc->rlayer.num_recs < SSL_MAX_PIPELINES);
274 rr = &sc->rlayer.tlsrecs[sc->rlayer.curr_rec];
277 * Reset the count of consecutive warning alerts if we've got a non-empty
278 * record that isn't an alert.
280 if (rr->type != SSL3_RT_ALERT && rr->length != 0)
281 sc->rlayer.alert_count = 0;
283 /* we now have a packet which can be read and processed */
285 if (sc->s3.change_cipher_spec /* set when we receive ChangeCipherSpec,
286 * reset by ssl3_get_finished */
287 && (rr->type != SSL3_RT_HANDSHAKE)) {
289 * We now have application data between CCS and Finished. Most likely
290 * the packets were reordered on their way, so buffer the application
291 * data for later processing rather than dropping the connection.
293 if (dtls_buffer_record(sc, rr) < 0) {
294 /* SSLfatal() already called */
297 if (!ssl_release_record(sc, rr, 0))
303 * If the other end has shut down, throw anything we read away (even in
306 if (sc->shutdown & SSL_RECEIVED_SHUTDOWN) {
307 if (!ssl_release_record(sc, rr, 0))
309 sc->rwstate = SSL_NOTHING;
314 || (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC
315 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
317 * SSL3_RT_APPLICATION_DATA or
318 * SSL3_RT_HANDSHAKE or
319 * SSL3_RT_CHANGE_CIPHER_SPEC
322 * make sure that we are not getting application data when we are
323 * doing a handshake for the first time
325 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA)
326 && (SSL_IS_FIRST_HANDSHAKE(sc))) {
327 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
328 SSL_R_APP_DATA_IN_HANDSHAKE);
332 if (recvd_type != NULL)
333 *recvd_type = rr->type;
337 * Release a zero length record. This ensures multiple calls to
338 * SSL_read() with a zero length buffer will eventually cause
339 * SSL_pending() to report data as being available.
341 if (rr->length == 0 && !ssl_release_record(sc, rr, 0))
346 if (len > rr->length)
351 memcpy(buf, &(rr->data[rr->off]), n);
353 if (rr->length == 0 && !ssl_release_record(sc, rr, 0))
356 if (!ssl_release_record(sc, rr, n))
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 const 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 if (!ssl_release_record(sc, rr, 0))
413 sc->rlayer.alert_count++;
414 if (sc->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
415 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
416 SSL_R_TOO_MANY_WARN_ALERTS);
420 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
421 #ifndef OPENSSL_NO_SCTP
423 * With SCTP and streams the socket may deliver app data
424 * after a close_notify alert. We have to check this first so
425 * that nothing gets discarded.
427 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
428 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) > 0) {
429 sc->d1->shutdown_received = 1;
430 sc->rwstate = SSL_READING;
431 BIO_clear_retry_flags(SSL_get_rbio(s));
432 BIO_set_retry_read(SSL_get_rbio(s));
436 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
439 } else if (alert_level == SSL3_AL_FATAL) {
440 sc->rwstate = SSL_NOTHING;
441 sc->s3.fatal_alert = alert_descr;
442 SSLfatal_data(sc, SSL_AD_NO_ALERT,
443 SSL_AD_REASON_OFFSET + alert_descr,
444 "SSL alert number %d", alert_descr);
445 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
446 if (!ssl_release_record(sc, rr, 0))
448 SSL_CTX_remove_session(sc->session_ctx, sc->session);
451 SSLfatal(sc, SSL_AD_ILLEGAL_PARAMETER, SSL_R_UNKNOWN_ALERT_TYPE);
458 if (sc->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
460 sc->rwstate = SSL_NOTHING;
461 if (!ssl_release_record(sc, rr, 0))
466 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
468 * We can't process a CCS now, because previous handshake messages
469 * are still missing, so just drop it.
471 if (!ssl_release_record(sc, rr, 0))
477 * Unexpected handshake message (Client Hello, or protocol violation)
479 if (rr->type == SSL3_RT_HANDSHAKE && !ossl_statem_get_in_handshake(sc)) {
480 struct hm_header_st msg_hdr;
483 * This may just be a stale retransmit. Also sanity check that we have
484 * at least enough record bytes for a message header
486 if (rr->epoch != sc->rlayer.d->r_epoch
487 || rr->length < DTLS1_HM_HEADER_LENGTH) {
488 if (!ssl_release_record(sc, rr, 0))
493 dtls1_get_message_header(rr->data, &msg_hdr);
496 * If we are server, we may have a repeated FINISHED of the client
497 * here, then retransmit our CCS and FINISHED.
499 if (msg_hdr.type == SSL3_MT_FINISHED) {
500 if (dtls1_check_timeout_num(sc) < 0) {
501 /* SSLfatal) already called */
505 if (dtls1_retransmit_buffered_messages(sc) <= 0) {
506 /* Fail if we encountered a fatal error */
507 if (ossl_statem_in_error(sc))
510 if (!ssl_release_record(sc, rr, 0))
512 if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
513 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
514 /* no read-ahead left? */
517 sc->rwstate = SSL_READING;
518 bio = SSL_get_rbio(s);
519 BIO_clear_retry_flags(bio);
520 BIO_set_retry_read(bio);
528 * To get here we must be trying to read app data but found handshake
529 * data. But if we're trying to read app data, and we're not in init
530 * (which is tested for at the top of this function) then init must be
533 if (!ossl_assert(SSL_is_init_finished(s))) {
534 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
538 /* We found handshake data, so we're going back into init */
539 ossl_statem_set_in_init(sc, 1);
541 i = sc->handshake_func(s);
542 /* SSLfatal() called if appropriate */
548 if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
549 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
550 /* no read-ahead left? */
553 * In the case where we try to read application data, but we
554 * trigger an SSL handshake, we return -1 with the retry
555 * option set. Otherwise renegotiation may cause nasty
556 * problems in the blocking world
558 sc->rwstate = SSL_READING;
559 bio = SSL_get_rbio(s);
560 BIO_clear_retry_flags(bio);
561 BIO_set_retry_read(bio);
570 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
572 case SSL3_RT_CHANGE_CIPHER_SPEC:
574 case SSL3_RT_HANDSHAKE:
576 * we already handled all of these, with the possible exception of
577 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
578 * that should not happen when type != rr->type
580 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, ERR_R_INTERNAL_ERROR);
582 case SSL3_RT_APPLICATION_DATA:
584 * At this point, we were expecting handshake data, but have
585 * application data. If the library was running inside ssl3_read()
586 * (i.e. in_read_app_data is set) and it makes sense to read
587 * application data at this point (session renegotiation not yet
588 * started), we will indulge it.
590 if (sc->s3.in_read_app_data &&
591 (sc->s3.total_renegotiations != 0) &&
592 ossl_statem_app_data_allowed(sc)) {
593 sc->s3.in_read_app_data = 2;
596 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
604 * Call this to write data in records of type 'type' It will return <= 0 if
605 * not all data has been sent or non-blocking IO.
607 int dtls1_write_bytes(SSL_CONNECTION *s, uint8_t type, const void *buf,
608 size_t len, size_t *written)
612 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
613 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
616 s->rwstate = SSL_NOTHING;
617 i = do_dtls1_write(s, type, buf, len, written);
621 int do_dtls1_write(SSL_CONNECTION *sc, uint8_t type, const unsigned char *buf,
622 size_t len, size_t *written)
625 OSSL_RECORD_TEMPLATE tmpl;
626 SSL *s = SSL_CONNECTION_GET_SSL(sc);
629 /* If we have an alert to send, lets send it */
630 if (sc->s3.alert_dispatch > 0) {
631 i = s->method->ssl_dispatch_alert(s);
634 /* if it went, fall through and send more stuff */
640 if (len > ssl_get_max_send_fragment(sc)) {
641 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
647 * Special case: for hello verify request, client version 1.0 and we
648 * haven't decided which version to use yet send back using version 1.0
649 * header: otherwise some clients will ignore it.
651 if (s->method->version == DTLS_ANY_VERSION
652 && sc->max_proto_version != DTLS1_BAD_VER)
653 tmpl.version = DTLS1_VERSION;
655 tmpl.version = sc->version;
659 ret = HANDLE_RLAYER_WRITE_RETURN(sc,
660 sc->rlayer.wrlmethod->write_records(sc->rlayer.wrl, &tmpl, 1));
668 void dtls1_increment_epoch(SSL_CONNECTION *s, int rw)
670 if (rw & SSL3_CC_READ) {
671 s->rlayer.d->r_epoch++;
674 * We must not use any buffered messages received from the previous
677 dtls1_clear_received_buffer(s);
679 s->rlayer.d->w_epoch++;
683 uint16_t dtls1_get_epoch(SSL_CONNECTION *s, int rw) {
686 if (rw & SSL3_CC_READ)
687 epoch = s->rlayer.d->r_epoch;
689 epoch = s->rlayer.d->w_epoch;