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;
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.q;
70 memset(d, 0, sizeof(*d));
71 d->buffered_app_data.q = buffered_app_data;
74 static int dtls_buffer_record(SSL_CONNECTION *s, TLS_RECORD *rec)
78 record_pqueue *queue = &(s->rlayer.d->buffered_app_data);
80 /* Limit the size of the queue to prevent DOS attacks */
81 if (pqueue_size(queue->q) >= 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->q, 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.q);
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 (when ssl3_get_message calls us)
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, int type, int *recvd_type, unsigned char *buf,
199 size_t len, int peek, size_t *readbytes)
204 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
205 SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
210 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
211 (type != SSL3_RT_HANDSHAKE)) ||
212 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
213 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
217 if (!ossl_statem_get_in_handshake(sc) && SSL_in_init(s)) {
218 /* type == SSL3_RT_APPLICATION_DATA */
219 i = sc->handshake_func(s);
220 /* SSLfatal() already called if appropriate */
228 sc->rwstate = SSL_NOTHING;
231 * We are not handshaking and have no data yet, so process data buffered
232 * during the last handshake in advance, if any.
234 if (SSL_is_init_finished(s))
235 dtls_unbuffer_record(sc);
237 /* Check for timeout */
238 if (dtls1_handle_timeout(sc) > 0) {
240 } else if (ossl_statem_in_error(sc)) {
241 /* dtls1_handle_timeout() has failed with a fatal error */
245 /* get new packet if necessary */
246 if (sc->rlayer.curr_rec >= sc->rlayer.num_recs) {
247 sc->rlayer.curr_rec = sc->rlayer.num_recs = 0;
249 rr = &sc->rlayer.tlsrecs[sc->rlayer.num_recs];
251 ret = HANDLE_RLAYER_READ_RETURN(sc,
252 sc->rlayer.rrlmethod->read_record(sc->rlayer.rrl,
254 &rr->version, &rr->type,
255 &rr->data, &rr->length,
256 &rr->epoch, rr->seq_num));
258 ret = dtls1_read_failed(sc, ret);
260 * Anything other than a timeout is an error. SSLfatal() already
261 * called if appropriate.
269 sc->rlayer.num_recs++;
270 } while (sc->rlayer.rrlmethod->processed_read_pending(sc->rlayer.rrl)
271 && sc->rlayer.num_recs < SSL_MAX_PIPELINES);
273 rr = &sc->rlayer.tlsrecs[sc->rlayer.curr_rec];
276 * Reset the count of consecutive warning alerts if we've got a non-empty
277 * record that isn't an alert.
279 if (rr->type != SSL3_RT_ALERT && rr->length != 0)
280 sc->rlayer.alert_count = 0;
282 /* we now have a packet which can be read and processed */
284 if (sc->s3.change_cipher_spec /* set when we receive ChangeCipherSpec,
285 * reset by ssl3_get_finished */
286 && (rr->type != SSL3_RT_HANDSHAKE)) {
288 * We now have application data between CCS and Finished. Most likely
289 * the packets were reordered on their way, so buffer the application
290 * data for later processing rather than dropping the connection.
292 if (dtls_buffer_record(sc, rr) < 0) {
293 /* SSLfatal() already called */
296 ssl_release_record(sc, rr);
301 * If the other end has shut down, throw anything we read away (even in
304 if (sc->shutdown & SSL_RECEIVED_SHUTDOWN) {
305 ssl_release_record(sc, rr);
306 sc->rwstate = SSL_NOTHING;
311 || (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC
312 && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
314 * SSL3_RT_APPLICATION_DATA or
315 * SSL3_RT_HANDSHAKE or
316 * SSL3_RT_CHANGE_CIPHER_SPEC
319 * make sure that we are not getting application data when we are
320 * doing a handshake for the first time
322 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA)
323 && (SSL_IS_FIRST_HANDSHAKE(sc))) {
324 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
325 SSL_R_APP_DATA_IN_HANDSHAKE);
329 if (recvd_type != NULL)
330 *recvd_type = rr->type;
334 * Release a zero length record. This ensures multiple calls to
335 * SSL_read() with a zero length buffer will eventually cause
336 * SSL_pending() to report data as being available.
339 ssl_release_record(sc, rr);
343 if (len > rr->length)
348 memcpy(buf, &(rr->data[rr->off]), n);
351 ssl_release_record(sc, rr);
353 /* TODO(RECLAYER): Casting away the const is wrong! FIX ME */
354 if (sc->options & SSL_OP_CLEANSE_PLAINTEXT)
355 OPENSSL_cleanse((unsigned char *)&(rr->data[rr->off]), n);
359 ssl_release_record(sc, rr);
361 #ifndef OPENSSL_NO_SCTP
363 * We might had to delay a close_notify alert because of reordered
364 * app data. If there was an alert and there is no message to read
365 * anymore, finally set shutdown.
367 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
368 sc->d1->shutdown_received
369 && BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) <= 0) {
370 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
379 * If we get here, then type != rr->type; if we have a handshake message,
380 * then it was unexpected (Hello Request or Client Hello).
383 if (rr->type == SSL3_RT_ALERT) {
384 unsigned int alert_level, alert_descr;
385 const unsigned char *alert_bytes = rr->data + rr->off;
388 if (!PACKET_buf_init(&alert, alert_bytes, rr->length)
389 || !PACKET_get_1(&alert, &alert_level)
390 || !PACKET_get_1(&alert, &alert_descr)
391 || PACKET_remaining(&alert) != 0) {
392 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_INVALID_ALERT);
396 if (sc->msg_callback)
397 sc->msg_callback(0, sc->version, SSL3_RT_ALERT, alert_bytes, 2, s,
398 sc->msg_callback_arg);
400 if (sc->info_callback != NULL)
401 cb = sc->info_callback;
402 else if (s->ctx->info_callback != NULL)
403 cb = s->ctx->info_callback;
406 j = (alert_level << 8) | alert_descr;
407 cb(s, SSL_CB_READ_ALERT, j);
410 if (alert_level == SSL3_AL_WARNING) {
411 sc->s3.warn_alert = alert_descr;
412 ssl_release_record(sc, rr);
414 sc->rlayer.alert_count++;
415 if (sc->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
416 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
417 SSL_R_TOO_MANY_WARN_ALERTS);
421 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
422 #ifndef OPENSSL_NO_SCTP
424 * With SCTP and streams the socket may deliver app data
425 * after a close_notify alert. We have to check this first so
426 * that nothing gets discarded.
428 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
429 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) > 0) {
430 sc->d1->shutdown_received = 1;
431 sc->rwstate = SSL_READING;
432 BIO_clear_retry_flags(SSL_get_rbio(s));
433 BIO_set_retry_read(SSL_get_rbio(s));
437 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
440 } else if (alert_level == SSL3_AL_FATAL) {
441 sc->rwstate = SSL_NOTHING;
442 sc->s3.fatal_alert = alert_descr;
443 SSLfatal_data(sc, SSL_AD_NO_ALERT,
444 SSL_AD_REASON_OFFSET + alert_descr,
445 "SSL alert number %d", alert_descr);
446 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
447 ssl_release_record(sc, rr);
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 ssl_release_record(sc, rr);
465 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
467 * We can't process a CCS now, because previous handshake messages
468 * are still missing, so just drop it.
470 ssl_release_record(sc, rr);
475 * Unexpected handshake message (Client Hello, or protocol violation)
477 if (rr->type == SSL3_RT_HANDSHAKE && !ossl_statem_get_in_handshake(sc)) {
478 struct hm_header_st msg_hdr;
481 * This may just be a stale retransmit. Also sanity check that we have
482 * at least enough record bytes for a message header
484 if (rr->epoch != sc->rlayer.d->r_epoch
485 || rr->length < DTLS1_HM_HEADER_LENGTH) {
486 ssl_release_record(sc, rr);
490 dtls1_get_message_header(rr->data, &msg_hdr);
493 * If we are server, we may have a repeated FINISHED of the client
494 * here, then retransmit our CCS and FINISHED.
496 if (msg_hdr.type == SSL3_MT_FINISHED) {
497 if (dtls1_check_timeout_num(sc) < 0) {
498 /* SSLfatal) already called */
502 if (dtls1_retransmit_buffered_messages(sc) <= 0) {
503 /* Fail if we encountered a fatal error */
504 if (ossl_statem_in_error(sc))
507 ssl_release_record(sc, rr);
508 if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
509 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
510 /* no read-ahead left? */
513 sc->rwstate = SSL_READING;
514 bio = SSL_get_rbio(s);
515 BIO_clear_retry_flags(bio);
516 BIO_set_retry_read(bio);
524 * To get here we must be trying to read app data but found handshake
525 * data. But if we're trying to read app data, and we're not in init
526 * (which is tested for at the top of this function) then init must be
529 if (!ossl_assert(SSL_is_init_finished(s))) {
530 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
534 /* We found handshake data, so we're going back into init */
535 ossl_statem_set_in_init(sc, 1);
537 i = sc->handshake_func(s);
538 /* SSLfatal() called if appropriate */
544 if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
545 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
546 /* no read-ahead left? */
549 * In the case where we try to read application data, but we
550 * trigger an SSL handshake, we return -1 with the retry
551 * option set. Otherwise renegotiation may cause nasty
552 * problems in the blocking world
554 sc->rwstate = SSL_READING;
555 bio = SSL_get_rbio(s);
556 BIO_clear_retry_flags(bio);
557 BIO_set_retry_read(bio);
566 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
568 case SSL3_RT_CHANGE_CIPHER_SPEC:
570 case SSL3_RT_HANDSHAKE:
572 * we already handled all of these, with the possible exception of
573 * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
574 * that should not happen when type != rr->type
576 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, ERR_R_INTERNAL_ERROR);
578 case SSL3_RT_APPLICATION_DATA:
580 * At this point, we were expecting handshake data, but have
581 * application data. If the library was running inside ssl3_read()
582 * (i.e. in_read_app_data is set) and it makes sense to read
583 * application data at this point (session renegotiation not yet
584 * started), we will indulge it.
586 if (sc->s3.in_read_app_data &&
587 (sc->s3.total_renegotiations != 0) &&
588 ossl_statem_app_data_allowed(sc)) {
589 sc->s3.in_read_app_data = 2;
592 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
600 * Call this to write data in records of type 'type' It will return <= 0 if
601 * not all data has been sent or non-blocking IO.
603 int dtls1_write_bytes(SSL_CONNECTION *s, int type, const void *buf,
604 size_t len, size_t *written)
608 if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
609 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
612 s->rwstate = SSL_NOTHING;
613 i = do_dtls1_write(s, type, buf, len, written);
617 int do_dtls1_write(SSL_CONNECTION *sc, int type, const unsigned char *buf,
618 size_t len, size_t *written)
621 OSSL_RECORD_TEMPLATE tmpl;
622 SSL *s = SSL_CONNECTION_GET_SSL(sc);
625 /* If we have an alert to send, lets send it */
626 if (sc->s3.alert_dispatch > 0) {
627 i = s->method->ssl_dispatch_alert(s);
630 /* if it went, fall through and send more stuff */
636 if (len > ssl_get_max_send_fragment(sc)) {
637 SSLfatal(sc, SSL_AD_INTERNAL_ERROR, SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
643 * Special case: for hello verify request, client version 1.0 and we
644 * haven't decided which version to use yet send back using version 1.0
645 * header: otherwise some clients will ignore it.
647 if (s->method->version == DTLS_ANY_VERSION
648 && sc->max_proto_version != DTLS1_BAD_VER)
649 tmpl.version = DTLS1_VERSION;
651 tmpl.version = sc->version;
655 ret = HANDLE_RLAYER_WRITE_RETURN(sc,
656 sc->rlayer.wrlmethod->write_records(sc->rlayer.wrl, &tmpl, 1));
664 void dtls1_increment_epoch(SSL_CONNECTION *s, int rw)
666 if (rw & SSL3_CC_READ) {
667 s->rlayer.d->r_epoch++;
670 * We must not use any buffered messages received from the previous
673 dtls1_clear_received_buffer(s);
675 s->rlayer.d->w_epoch++;