xref: /src/crypto/openssl/ssl/record/rec_layer_d1.c (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
1 /*
2  * Copyright 2005-2025 The OpenSSL Project Authors. All Rights Reserved.
3  *
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
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 "internal/packet.h"
17 #include "internal/cryptlib.h"
18 #include "internal/ssl_unwrap.h"
19 
DTLS_RECORD_LAYER_new(RECORD_LAYER * rl)20 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
21 {
22     DTLS_RECORD_LAYER *d;
23 
24     if ((d = OPENSSL_malloc(sizeof(*d))) == NULL)
25         return 0;
26 
27     rl->d = d;
28 
29     d->buffered_app_data = pqueue_new();
30 
31     if (d->buffered_app_data == NULL) {
32         OPENSSL_free(d);
33         rl->d = NULL;
34         return 0;
35     }
36 
37     return 1;
38 }
39 
DTLS_RECORD_LAYER_free(RECORD_LAYER * rl)40 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
41 {
42     if (rl->d == NULL)
43         return;
44 
45     DTLS_RECORD_LAYER_clear(rl);
46     pqueue_free(rl->d->buffered_app_data);
47     OPENSSL_free(rl->d);
48     rl->d = NULL;
49 }
50 
DTLS_RECORD_LAYER_clear(RECORD_LAYER * rl)51 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
52 {
53     DTLS_RECORD_LAYER *d;
54     pitem *item = NULL;
55     TLS_RECORD *rec;
56     pqueue *buffered_app_data;
57 
58     d = rl->d;
59 
60     while ((item = pqueue_pop(d->buffered_app_data)) != NULL) {
61         rec = (TLS_RECORD *)item->data;
62 
63         if (rl->s->options & SSL_OP_CLEANSE_PLAINTEXT)
64             OPENSSL_cleanse(rec->allocdata, rec->length);
65         OPENSSL_free(rec->allocdata);
66         OPENSSL_free(item->data);
67         pitem_free(item);
68     }
69 
70     buffered_app_data = d->buffered_app_data;
71     memset(d, 0, sizeof(*d));
72     d->buffered_app_data = buffered_app_data;
73 }
74 
dtls_buffer_record(SSL_CONNECTION * s,TLS_RECORD * rec)75 static int dtls_buffer_record(SSL_CONNECTION *s, TLS_RECORD *rec)
76 {
77     TLS_RECORD *rdata;
78     pitem *item;
79     struct pqueue_st *queue = s->rlayer.d->buffered_app_data;
80 
81     /* Limit the size of the queue to prevent DOS attacks */
82     if (pqueue_size(queue) >= 100)
83         return 0;
84 
85     /* We don't buffer partially read records */
86     if (!ossl_assert(rec->off == 0))
87         return -1;
88 
89     rdata = OPENSSL_malloc(sizeof(*rdata));
90     item = pitem_new(rec->seq_num, rdata);
91     if (rdata == NULL || item == NULL) {
92         OPENSSL_free(rdata);
93         pitem_free(item);
94         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
95         return -1;
96     }
97 
98     *rdata = *rec;
99     /*
100      * We will release the record from the record layer soon, so we take a copy
101      * now. Copying data isn't good - but this should be infrequent so we
102      * accept it here.
103      */
104     rdata->data = rdata->allocdata = OPENSSL_memdup(rec->data, rec->length);
105     if (rdata->data == NULL) {
106         OPENSSL_free(rdata);
107         pitem_free(item);
108         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_CRYPTO_LIB);
109         return -1;
110     }
111     /*
112      * We use a NULL rechandle to indicate that the data field has been
113      * allocated by us.
114      */
115     rdata->rechandle = NULL;
116 
117     item->data = rdata;
118 
119 #ifndef OPENSSL_NO_SCTP
120     /* Store bio_dgram_sctp_rcvinfo struct */
121     if (BIO_dgram_is_sctp(s->rbio) && (ossl_statem_get_state(s) == TLS_ST_SR_FINISHED || 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);
124     }
125 #endif
126 
127     if (pqueue_insert(queue, item) == NULL) {
128         /* Must be a duplicate so ignore it */
129         OPENSSL_free(rdata->allocdata);
130         OPENSSL_free(rdata);
131         pitem_free(item);
132     }
133 
134     return 1;
135 }
136 
137 /* Unbuffer a previously buffered TLS_RECORD structure if any */
dtls_unbuffer_record(SSL_CONNECTION * s)138 static void dtls_unbuffer_record(SSL_CONNECTION *s)
139 {
140     TLS_RECORD *rdata;
141     pitem *item;
142 
143     /* If we already have records to handle then do nothing */
144     if (s->rlayer.curr_rec < s->rlayer.num_recs)
145         return;
146 
147     item = pqueue_pop(s->rlayer.d->buffered_app_data);
148     if (item != NULL) {
149         rdata = (TLS_RECORD *)item->data;
150 
151         s->rlayer.tlsrecs[0] = *rdata;
152         s->rlayer.num_recs = 1;
153         s->rlayer.curr_rec = 0;
154 
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);
160         }
161 #endif
162 
163         OPENSSL_free(item->data);
164         pitem_free(item);
165     }
166 }
167 
168 /*-
169  * Return up to 'len' payload bytes received in 'type' records.
170  * 'type' is one of the following:
171  *
172  *   -  SSL3_RT_HANDSHAKE
173  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
174  *   -  0 (during a shutdown, no data has to be returned)
175  *
176  * If we don't have stored data to work from, read an SSL/TLS record first
177  * (possibly multiple records if we still don't have anything to return).
178  *
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
188  *     Alert protocol
189  *             2 bytes needed (AlertLevel, AlertDescription)
190  *     Handshake protocol
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
196  */
dtls1_read_bytes(SSL * s,uint8_t type,uint8_t * recvd_type,unsigned char * buf,size_t len,int peek,size_t * readbytes)197 int dtls1_read_bytes(SSL *s, uint8_t type, uint8_t *recvd_type,
198     unsigned char *buf, size_t len,
199     int peek, size_t *readbytes)
200 {
201     int i, j, ret;
202     size_t n;
203     TLS_RECORD *rr;
204     void (*cb)(const SSL *ssl, int type2, int val) = NULL;
205     SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL(s);
206 
207     if (sc == NULL)
208         return -1;
209 
210     if ((type && (type != SSL3_RT_APPLICATION_DATA) && (type != SSL3_RT_HANDSHAKE)) || (peek && (type != SSL3_RT_APPLICATION_DATA))) {
211         SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
212         return -1;
213     }
214 
215     if (!ossl_statem_get_in_handshake(sc) && SSL_in_init(s)) {
216         /* type == SSL3_RT_APPLICATION_DATA */
217         i = sc->handshake_func(s);
218         /* SSLfatal() already called if appropriate */
219         if (i < 0)
220             return i;
221         if (i == 0)
222             return -1;
223     }
224 
225 start:
226     sc->rwstate = SSL_NOTHING;
227 
228     /*
229      * We are not handshaking and have no data yet, so process data buffered
230      * during the last handshake in advance, if any.
231      */
232     if (SSL_is_init_finished(s))
233         dtls_unbuffer_record(sc);
234 
235     /* Check for timeout */
236     if (dtls1_handle_timeout(sc) > 0) {
237         goto start;
238     } else if (ossl_statem_in_error(sc)) {
239         /* dtls1_handle_timeout() has failed with a fatal error */
240         return -1;
241     }
242 
243     /* get new packet if necessary */
244     if (sc->rlayer.curr_rec >= sc->rlayer.num_recs) {
245         sc->rlayer.curr_rec = sc->rlayer.num_recs = 0;
246         do {
247             rr = &sc->rlayer.tlsrecs[sc->rlayer.num_recs];
248 
249             ret = HANDLE_RLAYER_READ_RETURN(sc,
250                 sc->rlayer.rrlmethod->read_record(sc->rlayer.rrl,
251                     &rr->rechandle,
252                     &rr->version, &rr->type,
253                     &rr->data, &rr->length,
254                     &rr->epoch, rr->seq_num));
255             if (ret <= 0) {
256                 ret = dtls1_read_failed(sc, ret);
257                 /*
258                  * Anything other than a timeout is an error. SSLfatal() already
259                  * called if appropriate.
260                  */
261                 if (ret <= 0)
262                     return ret;
263                 else
264                     goto start;
265             }
266             rr->off = 0;
267             sc->rlayer.num_recs++;
268         } while (sc->rlayer.rrlmethod->processed_read_pending(sc->rlayer.rrl)
269             && sc->rlayer.num_recs < SSL_MAX_PIPELINES);
270     }
271     rr = &sc->rlayer.tlsrecs[sc->rlayer.curr_rec];
272 
273     /*
274      * Reset the count of consecutive warning alerts if we've got a non-empty
275      * record that isn't an alert.
276      */
277     if (rr->type != SSL3_RT_ALERT && rr->length != 0)
278         sc->rlayer.alert_count = 0;
279 
280     /* we now have a packet which can be read and processed */
281 
282     if (sc->s3.change_cipher_spec /* set when we receive ChangeCipherSpec,
283                                    * reset by ssl3_get_finished */
284         && (rr->type != SSL3_RT_HANDSHAKE)) {
285         /*
286          * We now have application data between CCS and Finished. Most likely
287          * the packets were reordered on their way, so buffer the application
288          * data for later processing rather than dropping the connection.
289          */
290         if (dtls_buffer_record(sc, rr) < 0) {
291             /* SSLfatal() already called */
292             return -1;
293         }
294         if (!ssl_release_record(sc, rr, 0))
295             return -1;
296         goto start;
297     }
298 
299     /*
300      * If the other end has shut down, throw anything we read away (even in
301      * 'peek' mode)
302      */
303     if (sc->shutdown & SSL_RECEIVED_SHUTDOWN) {
304         if (!ssl_release_record(sc, rr, 0))
305             return -1;
306         sc->rwstate = SSL_NOTHING;
307         return 0;
308     }
309 
310     if (type == rr->type
311         || (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC
312             && type == SSL3_RT_HANDSHAKE && recvd_type != NULL)) {
313         /*
314          * SSL3_RT_APPLICATION_DATA or
315          * SSL3_RT_HANDSHAKE or
316          * SSL3_RT_CHANGE_CIPHER_SPEC
317          */
318         /*
319          * make sure that we are not getting application data when we are
320          * doing a handshake for the first time
321          */
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);
326             return -1;
327         }
328 
329         if (recvd_type != NULL)
330             *recvd_type = rr->type;
331 
332         if (len == 0) {
333             /*
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.
337              */
338             if (rr->length == 0 && !ssl_release_record(sc, rr, 0))
339                 return -1;
340             return 0;
341         }
342 
343         if (len > rr->length)
344             n = rr->length;
345         else
346             n = len;
347 
348         memcpy(buf, &(rr->data[rr->off]), n);
349         if (peek) {
350             if (rr->length == 0 && !ssl_release_record(sc, rr, 0))
351                 return -1;
352         } else {
353             if (!ssl_release_record(sc, rr, n))
354                 return -1;
355         }
356 #ifndef OPENSSL_NO_SCTP
357         /*
358          * We might had to delay a close_notify alert because of reordered
359          * app data. If there was an alert and there is no message to read
360          * anymore, finally set shutdown.
361          */
362         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && sc->d1->shutdown_received
363             && BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) <= 0) {
364             sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
365             return 0;
366         }
367 #endif
368         *readbytes = n;
369         return 1;
370     }
371 
372     /*
373      * If we get here, then type != rr->type; if we have a handshake message,
374      * then it was unexpected (Hello Request or Client Hello).
375      */
376 
377     if (rr->type == SSL3_RT_ALERT) {
378         unsigned int alert_level, alert_descr;
379         const unsigned char *alert_bytes = rr->data + rr->off;
380         PACKET alert;
381 
382         if (!PACKET_buf_init(&alert, alert_bytes, rr->length)
383             || !PACKET_get_1(&alert, &alert_level)
384             || !PACKET_get_1(&alert, &alert_descr)
385             || PACKET_remaining(&alert) != 0) {
386             SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_INVALID_ALERT);
387             return -1;
388         }
389 
390         if (sc->msg_callback)
391             sc->msg_callback(0, sc->version, SSL3_RT_ALERT, alert_bytes, 2, s,
392                 sc->msg_callback_arg);
393 
394         if (sc->info_callback != NULL)
395             cb = sc->info_callback;
396         else if (s->ctx->info_callback != NULL)
397             cb = s->ctx->info_callback;
398 
399         if (cb != NULL) {
400             j = (alert_level << 8) | alert_descr;
401             cb(s, SSL_CB_READ_ALERT, j);
402         }
403 
404         if (alert_level == SSL3_AL_WARNING) {
405             sc->s3.warn_alert = alert_descr;
406             if (!ssl_release_record(sc, rr, 0))
407                 return -1;
408 
409             sc->rlayer.alert_count++;
410             if (sc->rlayer.alert_count == MAX_WARN_ALERT_COUNT) {
411                 SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE,
412                     SSL_R_TOO_MANY_WARN_ALERTS);
413                 return -1;
414             }
415 
416             if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
417 #ifndef OPENSSL_NO_SCTP
418                 /*
419                  * With SCTP and streams the socket may deliver app data
420                  * after a close_notify alert. We have to check this first so
421                  * that nothing gets discarded.
422                  */
423                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) && BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)) > 0) {
424                     sc->d1->shutdown_received = 1;
425                     sc->rwstate = SSL_READING;
426                     BIO_clear_retry_flags(SSL_get_rbio(s));
427                     BIO_set_retry_read(SSL_get_rbio(s));
428                     return -1;
429                 }
430 #endif
431                 sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
432                 return 0;
433             } else if (alert_descr == SSL_AD_NO_RENEGOTIATION) {
434                 /*
435                  * This is a warning but we receive it if we requested
436                  * renegotiation and the peer denied it. Terminate with a fatal
437                  * alert because if the application tried to renegotiate it
438                  * presumably had a good reason and expects it to succeed. In
439                  * the future we might have a renegotiation where we don't care
440                  * if the peer refused it where we carry on.
441                  */
442                 SSLfatal(sc, SSL_AD_HANDSHAKE_FAILURE, SSL_R_NO_RENEGOTIATION);
443                 return -1;
444             }
445         } else if (alert_level == SSL3_AL_FATAL) {
446             sc->rwstate = SSL_NOTHING;
447             sc->s3.fatal_alert = alert_descr;
448             SSLfatal_data(sc, SSL_AD_NO_ALERT,
449                 SSL_AD_REASON_OFFSET + alert_descr,
450                 "SSL alert number %d", alert_descr);
451             sc->shutdown |= SSL_RECEIVED_SHUTDOWN;
452             if (!ssl_release_record(sc, rr, 0))
453                 return -1;
454             SSL_CTX_remove_session(sc->session_ctx, sc->session);
455             return 0;
456         } else {
457             SSLfatal(sc, SSL_AD_ILLEGAL_PARAMETER, SSL_R_UNKNOWN_ALERT_TYPE);
458             return -1;
459         }
460 
461         goto start;
462     }
463 
464     if (sc->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
465                                              * shutdown */
466         sc->rwstate = SSL_NOTHING;
467         if (!ssl_release_record(sc, rr, 0))
468             return -1;
469         return 0;
470     }
471 
472     if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
473         /*
474          * We can't process a CCS now, because previous handshake messages
475          * are still missing, so just drop it.
476          */
477         if (!ssl_release_record(sc, rr, 0))
478             return -1;
479         goto start;
480     }
481 
482     /*
483      * Unexpected handshake message (Client Hello, or protocol violation)
484      */
485     if (rr->type == SSL3_RT_HANDSHAKE && !ossl_statem_get_in_handshake(sc)) {
486         struct hm_header_st msg_hdr;
487 
488         /*
489          * This may just be a stale retransmit. Also sanity check that we have
490          * at least enough record bytes for a message header
491          */
492         if (rr->epoch != sc->rlayer.d->r_epoch
493             || rr->length < DTLS1_HM_HEADER_LENGTH) {
494             if (!ssl_release_record(sc, rr, 0))
495                 return -1;
496             goto start;
497         }
498 
499         dtls1_get_message_header(rr->data, &msg_hdr);
500 
501         /*
502          * If we are server, we may have a repeated FINISHED of the client
503          * here, then retransmit our CCS and FINISHED.
504          */
505         if (msg_hdr.type == SSL3_MT_FINISHED) {
506             if (dtls1_check_timeout_num(sc) < 0) {
507                 /* SSLfatal) already called */
508                 return -1;
509             }
510 
511             if (dtls1_retransmit_buffered_messages(sc) <= 0) {
512                 /* Fail if we encountered a fatal error */
513                 if (ossl_statem_in_error(sc))
514                     return -1;
515             }
516             if (!ssl_release_record(sc, rr, 0))
517                 return -1;
518             if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
519                 if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
520                     /* no read-ahead left? */
521                     BIO *bio;
522 
523                     sc->rwstate = SSL_READING;
524                     bio = SSL_get_rbio(s);
525                     BIO_clear_retry_flags(bio);
526                     BIO_set_retry_read(bio);
527                     return -1;
528                 }
529             }
530             goto start;
531         }
532 
533         /*
534          * To get here we must be trying to read app data but found handshake
535          * data. But if we're trying to read app data, and we're not in init
536          * (which is tested for at the top of this function) then init must be
537          * finished
538          */
539         if (!ossl_assert(SSL_is_init_finished(s))) {
540             SSLfatal(sc, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
541             return -1;
542         }
543 
544         /* We found handshake data, so we're going back into init */
545         ossl_statem_set_in_init(sc, 1);
546 
547         i = sc->handshake_func(s);
548         /* SSLfatal() called if appropriate */
549         if (i < 0)
550             return i;
551         if (i == 0)
552             return -1;
553 
554         if (!(sc->mode & SSL_MODE_AUTO_RETRY)) {
555             if (!sc->rlayer.rrlmethod->unprocessed_read_pending(sc->rlayer.rrl)) {
556                 /* no read-ahead left? */
557                 BIO *bio;
558                 /*
559                  * In the case where we try to read application data, but we
560                  * trigger an SSL handshake, we return -1 with the retry
561                  * option set.  Otherwise renegotiation may cause nasty
562                  * problems in the blocking world
563                  */
564                 sc->rwstate = SSL_READING;
565                 bio = SSL_get_rbio(s);
566                 BIO_clear_retry_flags(bio);
567                 BIO_set_retry_read(bio);
568                 return -1;
569             }
570         }
571         goto start;
572     }
573 
574     switch (rr->type) {
575     default:
576         SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
577         return -1;
578     case SSL3_RT_CHANGE_CIPHER_SPEC:
579     case SSL3_RT_ALERT:
580     case SSL3_RT_HANDSHAKE:
581         /*
582          * we already handled all of these, with the possible exception of
583          * SSL3_RT_HANDSHAKE when ossl_statem_get_in_handshake(s) is true, but
584          * that should not happen when type != rr->type
585          */
586         SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, ERR_R_INTERNAL_ERROR);
587         return -1;
588     case SSL3_RT_APPLICATION_DATA:
589         /*
590          * At this point, we were expecting handshake data, but have
591          * application data.  If the library was running inside ssl3_read()
592          * (i.e. in_read_app_data is set) and it makes sense to read
593          * application data at this point (session renegotiation not yet
594          * started), we will indulge it.
595          */
596         if (sc->s3.in_read_app_data && (sc->s3.total_renegotiations != 0) && ossl_statem_app_data_allowed(sc)) {
597             sc->s3.in_read_app_data = 2;
598             return -1;
599         } else {
600             SSLfatal(sc, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_RECORD);
601             return -1;
602         }
603     }
604     /* not reached */
605 }
606 
607 /*
608  * Call this to write data in records of type 'type' It will return <= 0 if
609  * not all data has been sent or non-blocking IO.
610  */
dtls1_write_bytes(SSL_CONNECTION * s,uint8_t type,const void * buf,size_t len,size_t * written)611 int dtls1_write_bytes(SSL_CONNECTION *s, uint8_t type, const void *buf,
612     size_t len, size_t *written)
613 {
614     int i;
615 
616     if (!ossl_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH)) {
617         SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
618         return -1;
619     }
620     s->rwstate = SSL_NOTHING;
621     i = do_dtls1_write(s, type, buf, len, written);
622     return i;
623 }
624 
do_dtls1_write(SSL_CONNECTION * sc,uint8_t type,const unsigned char * buf,size_t len,size_t * written)625 int do_dtls1_write(SSL_CONNECTION *sc, uint8_t type, const unsigned char *buf,
626     size_t len, size_t *written)
627 {
628     int i;
629     OSSL_RECORD_TEMPLATE tmpl;
630     SSL *s = SSL_CONNECTION_GET_SSL(sc);
631     int ret;
632 
633     /* If we have an alert to send, lets send it */
634     if (sc->s3.alert_dispatch > 0) {
635         i = s->method->ssl_dispatch_alert(s);
636         if (i <= 0)
637             return i;
638         /* if it went, fall through and send more stuff */
639     }
640 
641     if (len == 0)
642         return 0;
643 
644     if (len > ssl_get_max_send_fragment(sc)) {
645         SSLfatal(sc, SSL_AD_INTERNAL_ERROR, SSL_R_EXCEEDS_MAX_FRAGMENT_SIZE);
646         return 0;
647     }
648 
649     tmpl.type = type;
650     /*
651      * Special case: for hello verify request, client version 1.0 and we
652      * haven't decided which version to use yet send back using version 1.0
653      * header: otherwise some clients will ignore it.
654      */
655     if (s->method->version == DTLS_ANY_VERSION
656         && sc->max_proto_version != DTLS1_BAD_VER)
657         tmpl.version = DTLS1_VERSION;
658     else
659         tmpl.version = sc->version;
660     tmpl.buf = buf;
661     tmpl.buflen = len;
662 
663     ret = HANDLE_RLAYER_WRITE_RETURN(sc,
664         sc->rlayer.wrlmethod->write_records(sc->rlayer.wrl, &tmpl, 1));
665 
666     if (ret > 0)
667         *written = (int)len;
668 
669     return ret;
670 }
671 
dtls1_increment_epoch(SSL_CONNECTION * s,int rw)672 void dtls1_increment_epoch(SSL_CONNECTION *s, int rw)
673 {
674     if (rw & SSL3_CC_READ) {
675         s->rlayer.d->r_epoch++;
676 
677         /*
678          * We must not use any buffered messages received from the previous
679          * epoch
680          */
681         dtls1_clear_received_buffer(s);
682     } else {
683         s->rlayer.d->w_epoch++;
684     }
685 }
686 
dtls1_get_epoch(SSL_CONNECTION * s,int rw)687 uint16_t dtls1_get_epoch(SSL_CONNECTION *s, int rw)
688 {
689     uint16_t epoch;
690 
691     if (rw & SSL3_CC_READ)
692         epoch = s->rlayer.d->r_epoch;
693     else
694         epoch = s->rlayer.d->w_epoch;
695 
696     return epoch;
697 }
698