xref: /freebsd/crypto/openssl/ssl/statem/statem_clnt.c (revision 43a5ec4eb41567cc92586503212743d89686d78f)
1 /*
2  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3  * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved
4  * Copyright 2005 Nokia. All rights reserved.
5  *
6  * Licensed under the OpenSSL license (the "License").  You may not use
7  * this file except in compliance with the License.  You can obtain a copy
8  * in the file LICENSE in the source distribution or at
9  * https://www.openssl.org/source/license.html
10  */
11 
12 #include <stdio.h>
13 #include <time.h>
14 #include <assert.h>
15 #include "../ssl_local.h"
16 #include "statem_local.h"
17 #include <openssl/buffer.h>
18 #include <openssl/rand.h>
19 #include <openssl/objects.h>
20 #include <openssl/evp.h>
21 #include <openssl/md5.h>
22 #include <openssl/dh.h>
23 #include <openssl/bn.h>
24 #include <openssl/engine.h>
25 #include <internal/cryptlib.h>
26 
27 static MSG_PROCESS_RETURN tls_process_as_hello_retry_request(SSL *s, PACKET *pkt);
28 static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt);
29 
30 static ossl_inline int cert_req_allowed(SSL *s);
31 static int key_exchange_expected(SSL *s);
32 static int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk,
33                                     WPACKET *pkt);
34 
35 /*
36  * Is a CertificateRequest message allowed at the moment or not?
37  *
38  *  Return values are:
39  *  1: Yes
40  *  0: No
41  */
42 static ossl_inline int cert_req_allowed(SSL *s)
43 {
44     /* TLS does not like anon-DH with client cert */
45     if ((s->version > SSL3_VERSION
46          && (s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
47         || (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aSRP | SSL_aPSK)))
48         return 0;
49 
50     return 1;
51 }
52 
53 /*
54  * Should we expect the ServerKeyExchange message or not?
55  *
56  *  Return values are:
57  *  1: Yes
58  *  0: No
59  */
60 static int key_exchange_expected(SSL *s)
61 {
62     long alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
63 
64     /*
65      * Can't skip server key exchange if this is an ephemeral
66      * ciphersuite or for SRP
67      */
68     if (alg_k & (SSL_kDHE | SSL_kECDHE | SSL_kDHEPSK | SSL_kECDHEPSK
69                  | SSL_kSRP)) {
70         return 1;
71     }
72 
73     return 0;
74 }
75 
76 /*
77  * ossl_statem_client_read_transition() encapsulates the logic for the allowed
78  * handshake state transitions when a TLS1.3 client is reading messages from the
79  * server. The message type that the server has sent is provided in |mt|. The
80  * current state is in |s->statem.hand_state|.
81  *
82  * Return values are 1 for success (transition allowed) and  0 on error
83  * (transition not allowed)
84  */
85 static int ossl_statem_client13_read_transition(SSL *s, int mt)
86 {
87     OSSL_STATEM *st = &s->statem;
88 
89     /*
90      * Note: There is no case for TLS_ST_CW_CLNT_HELLO, because we haven't
91      * yet negotiated TLSv1.3 at that point so that is handled by
92      * ossl_statem_client_read_transition()
93      */
94 
95     switch (st->hand_state) {
96     default:
97         break;
98 
99     case TLS_ST_CW_CLNT_HELLO:
100         /*
101          * This must a ClientHello following a HelloRetryRequest, so the only
102          * thing we can get now is a ServerHello.
103          */
104         if (mt == SSL3_MT_SERVER_HELLO) {
105             st->hand_state = TLS_ST_CR_SRVR_HELLO;
106             return 1;
107         }
108         break;
109 
110     case TLS_ST_CR_SRVR_HELLO:
111         if (mt == SSL3_MT_ENCRYPTED_EXTENSIONS) {
112             st->hand_state = TLS_ST_CR_ENCRYPTED_EXTENSIONS;
113             return 1;
114         }
115         break;
116 
117     case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
118         if (s->hit) {
119             if (mt == SSL3_MT_FINISHED) {
120                 st->hand_state = TLS_ST_CR_FINISHED;
121                 return 1;
122             }
123         } else {
124             if (mt == SSL3_MT_CERTIFICATE_REQUEST) {
125                 st->hand_state = TLS_ST_CR_CERT_REQ;
126                 return 1;
127             }
128             if (mt == SSL3_MT_CERTIFICATE) {
129                 st->hand_state = TLS_ST_CR_CERT;
130                 return 1;
131             }
132         }
133         break;
134 
135     case TLS_ST_CR_CERT_REQ:
136         if (mt == SSL3_MT_CERTIFICATE) {
137             st->hand_state = TLS_ST_CR_CERT;
138             return 1;
139         }
140         break;
141 
142     case TLS_ST_CR_CERT:
143         if (mt == SSL3_MT_CERTIFICATE_VERIFY) {
144             st->hand_state = TLS_ST_CR_CERT_VRFY;
145             return 1;
146         }
147         break;
148 
149     case TLS_ST_CR_CERT_VRFY:
150         if (mt == SSL3_MT_FINISHED) {
151             st->hand_state = TLS_ST_CR_FINISHED;
152             return 1;
153         }
154         break;
155 
156     case TLS_ST_OK:
157         if (mt == SSL3_MT_NEWSESSION_TICKET) {
158             st->hand_state = TLS_ST_CR_SESSION_TICKET;
159             return 1;
160         }
161         if (mt == SSL3_MT_KEY_UPDATE) {
162             st->hand_state = TLS_ST_CR_KEY_UPDATE;
163             return 1;
164         }
165         if (mt == SSL3_MT_CERTIFICATE_REQUEST) {
166 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
167 # error TODO(DTLS1.3): Restore digest for PHA before adding message.
168 #endif
169             if (!SSL_IS_DTLS(s) && s->post_handshake_auth == SSL_PHA_EXT_SENT) {
170                 s->post_handshake_auth = SSL_PHA_REQUESTED;
171                 /*
172                  * In TLS, this is called before the message is added to the
173                  * digest. In DTLS, this is expected to be called after adding
174                  * to the digest. Either move the digest restore, or add the
175                  * message here after the swap, or do it after the clientFinished?
176                  */
177                 if (!tls13_restore_handshake_digest_for_pha(s)) {
178                     /* SSLfatal() already called */
179                     return 0;
180                 }
181                 st->hand_state = TLS_ST_CR_CERT_REQ;
182                 return 1;
183             }
184         }
185         break;
186     }
187 
188     /* No valid transition found */
189     return 0;
190 }
191 
192 /*
193  * ossl_statem_client_read_transition() encapsulates the logic for the allowed
194  * handshake state transitions when the client is reading messages from the
195  * server. The message type that the server has sent is provided in |mt|. The
196  * current state is in |s->statem.hand_state|.
197  *
198  * Return values are 1 for success (transition allowed) and  0 on error
199  * (transition not allowed)
200  */
201 int ossl_statem_client_read_transition(SSL *s, int mt)
202 {
203     OSSL_STATEM *st = &s->statem;
204     int ske_expected;
205 
206     /*
207      * Note that after writing the first ClientHello we don't know what version
208      * we are going to negotiate yet, so we don't take this branch until later.
209      */
210     if (SSL_IS_TLS13(s)) {
211         if (!ossl_statem_client13_read_transition(s, mt))
212             goto err;
213         return 1;
214     }
215 
216     switch (st->hand_state) {
217     default:
218         break;
219 
220     case TLS_ST_CW_CLNT_HELLO:
221         if (mt == SSL3_MT_SERVER_HELLO) {
222             st->hand_state = TLS_ST_CR_SRVR_HELLO;
223             return 1;
224         }
225 
226         if (SSL_IS_DTLS(s)) {
227             if (mt == DTLS1_MT_HELLO_VERIFY_REQUEST) {
228                 st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
229                 return 1;
230             }
231         }
232         break;
233 
234     case TLS_ST_EARLY_DATA:
235         /*
236          * We've not actually selected TLSv1.3 yet, but we have sent early
237          * data. The only thing allowed now is a ServerHello or a
238          * HelloRetryRequest.
239          */
240         if (mt == SSL3_MT_SERVER_HELLO) {
241             st->hand_state = TLS_ST_CR_SRVR_HELLO;
242             return 1;
243         }
244         break;
245 
246     case TLS_ST_CR_SRVR_HELLO:
247         if (s->hit) {
248             if (s->ext.ticket_expected) {
249                 if (mt == SSL3_MT_NEWSESSION_TICKET) {
250                     st->hand_state = TLS_ST_CR_SESSION_TICKET;
251                     return 1;
252                 }
253             } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
254                 st->hand_state = TLS_ST_CR_CHANGE;
255                 return 1;
256             }
257         } else {
258             if (SSL_IS_DTLS(s) && mt == DTLS1_MT_HELLO_VERIFY_REQUEST) {
259                 st->hand_state = DTLS_ST_CR_HELLO_VERIFY_REQUEST;
260                 return 1;
261             } else if (s->version >= TLS1_VERSION
262                        && s->ext.session_secret_cb != NULL
263                        && s->session->ext.tick != NULL
264                        && mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
265                 /*
266                  * Normally, we can tell if the server is resuming the session
267                  * from the session ID. EAP-FAST (RFC 4851), however, relies on
268                  * the next server message after the ServerHello to determine if
269                  * the server is resuming.
270                  */
271                 s->hit = 1;
272                 st->hand_state = TLS_ST_CR_CHANGE;
273                 return 1;
274             } else if (!(s->s3->tmp.new_cipher->algorithm_auth
275                          & (SSL_aNULL | SSL_aSRP | SSL_aPSK))) {
276                 if (mt == SSL3_MT_CERTIFICATE) {
277                     st->hand_state = TLS_ST_CR_CERT;
278                     return 1;
279                 }
280             } else {
281                 ske_expected = key_exchange_expected(s);
282                 /* SKE is optional for some PSK ciphersuites */
283                 if (ske_expected
284                     || ((s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)
285                         && mt == SSL3_MT_SERVER_KEY_EXCHANGE)) {
286                     if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
287                         st->hand_state = TLS_ST_CR_KEY_EXCH;
288                         return 1;
289                     }
290                 } else if (mt == SSL3_MT_CERTIFICATE_REQUEST
291                            && cert_req_allowed(s)) {
292                     st->hand_state = TLS_ST_CR_CERT_REQ;
293                     return 1;
294                 } else if (mt == SSL3_MT_SERVER_DONE) {
295                     st->hand_state = TLS_ST_CR_SRVR_DONE;
296                     return 1;
297                 }
298             }
299         }
300         break;
301 
302     case TLS_ST_CR_CERT:
303         /*
304          * The CertificateStatus message is optional even if
305          * |ext.status_expected| is set
306          */
307         if (s->ext.status_expected && mt == SSL3_MT_CERTIFICATE_STATUS) {
308             st->hand_state = TLS_ST_CR_CERT_STATUS;
309             return 1;
310         }
311         /* Fall through */
312 
313     case TLS_ST_CR_CERT_STATUS:
314         ske_expected = key_exchange_expected(s);
315         /* SKE is optional for some PSK ciphersuites */
316         if (ske_expected || ((s->s3->tmp.new_cipher->algorithm_mkey & SSL_PSK)
317                              && mt == SSL3_MT_SERVER_KEY_EXCHANGE)) {
318             if (mt == SSL3_MT_SERVER_KEY_EXCHANGE) {
319                 st->hand_state = TLS_ST_CR_KEY_EXCH;
320                 return 1;
321             }
322             goto err;
323         }
324         /* Fall through */
325 
326     case TLS_ST_CR_KEY_EXCH:
327         if (mt == SSL3_MT_CERTIFICATE_REQUEST) {
328             if (cert_req_allowed(s)) {
329                 st->hand_state = TLS_ST_CR_CERT_REQ;
330                 return 1;
331             }
332             goto err;
333         }
334         /* Fall through */
335 
336     case TLS_ST_CR_CERT_REQ:
337         if (mt == SSL3_MT_SERVER_DONE) {
338             st->hand_state = TLS_ST_CR_SRVR_DONE;
339             return 1;
340         }
341         break;
342 
343     case TLS_ST_CW_FINISHED:
344         if (s->ext.ticket_expected) {
345             if (mt == SSL3_MT_NEWSESSION_TICKET) {
346                 st->hand_state = TLS_ST_CR_SESSION_TICKET;
347                 return 1;
348             }
349         } else if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
350             st->hand_state = TLS_ST_CR_CHANGE;
351             return 1;
352         }
353         break;
354 
355     case TLS_ST_CR_SESSION_TICKET:
356         if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
357             st->hand_state = TLS_ST_CR_CHANGE;
358             return 1;
359         }
360         break;
361 
362     case TLS_ST_CR_CHANGE:
363         if (mt == SSL3_MT_FINISHED) {
364             st->hand_state = TLS_ST_CR_FINISHED;
365             return 1;
366         }
367         break;
368 
369     case TLS_ST_OK:
370         if (mt == SSL3_MT_HELLO_REQUEST) {
371             st->hand_state = TLS_ST_CR_HELLO_REQ;
372             return 1;
373         }
374         break;
375     }
376 
377  err:
378     /* No valid transition found */
379     if (SSL_IS_DTLS(s) && mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
380         BIO *rbio;
381 
382         /*
383          * CCS messages don't have a message sequence number so this is probably
384          * because of an out-of-order CCS. We'll just drop it.
385          */
386         s->init_num = 0;
387         s->rwstate = SSL_READING;
388         rbio = SSL_get_rbio(s);
389         BIO_clear_retry_flags(rbio);
390         BIO_set_retry_read(rbio);
391         return 0;
392     }
393     SSLfatal(s, SSL3_AD_UNEXPECTED_MESSAGE,
394              SSL_F_OSSL_STATEM_CLIENT_READ_TRANSITION,
395              SSL_R_UNEXPECTED_MESSAGE);
396     return 0;
397 }
398 
399 /*
400  * ossl_statem_client13_write_transition() works out what handshake state to
401  * move to next when the TLSv1.3 client is writing messages to be sent to the
402  * server.
403  */
404 static WRITE_TRAN ossl_statem_client13_write_transition(SSL *s)
405 {
406     OSSL_STATEM *st = &s->statem;
407 
408     /*
409      * Note: There are no cases for TLS_ST_BEFORE because we haven't negotiated
410      * TLSv1.3 yet at that point. They are handled by
411      * ossl_statem_client_write_transition().
412      */
413     switch (st->hand_state) {
414     default:
415         /* Shouldn't happen */
416         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
417                  SSL_F_OSSL_STATEM_CLIENT13_WRITE_TRANSITION,
418                  ERR_R_INTERNAL_ERROR);
419         return WRITE_TRAN_ERROR;
420 
421     case TLS_ST_CR_CERT_REQ:
422         if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
423             st->hand_state = TLS_ST_CW_CERT;
424             return WRITE_TRAN_CONTINUE;
425         }
426         /*
427          * We should only get here if we received a CertificateRequest after
428          * we already sent close_notify
429          */
430         if (!ossl_assert((s->shutdown & SSL_SENT_SHUTDOWN) != 0)) {
431             /* Shouldn't happen - same as default case */
432             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
433                      SSL_F_OSSL_STATEM_CLIENT13_WRITE_TRANSITION,
434                      ERR_R_INTERNAL_ERROR);
435             return WRITE_TRAN_ERROR;
436         }
437         st->hand_state = TLS_ST_OK;
438         return WRITE_TRAN_CONTINUE;
439 
440     case TLS_ST_CR_FINISHED:
441         if (s->early_data_state == SSL_EARLY_DATA_WRITE_RETRY
442                 || s->early_data_state == SSL_EARLY_DATA_FINISHED_WRITING)
443             st->hand_state = TLS_ST_PENDING_EARLY_DATA_END;
444         else if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
445                  && s->hello_retry_request == SSL_HRR_NONE)
446             st->hand_state = TLS_ST_CW_CHANGE;
447         else
448             st->hand_state = (s->s3->tmp.cert_req != 0) ? TLS_ST_CW_CERT
449                                                         : TLS_ST_CW_FINISHED;
450         return WRITE_TRAN_CONTINUE;
451 
452     case TLS_ST_PENDING_EARLY_DATA_END:
453         if (s->ext.early_data == SSL_EARLY_DATA_ACCEPTED) {
454             st->hand_state = TLS_ST_CW_END_OF_EARLY_DATA;
455             return WRITE_TRAN_CONTINUE;
456         }
457         /* Fall through */
458 
459     case TLS_ST_CW_END_OF_EARLY_DATA:
460     case TLS_ST_CW_CHANGE:
461         st->hand_state = (s->s3->tmp.cert_req != 0) ? TLS_ST_CW_CERT
462                                                     : TLS_ST_CW_FINISHED;
463         return WRITE_TRAN_CONTINUE;
464 
465     case TLS_ST_CW_CERT:
466         /* If a non-empty Certificate we also send CertificateVerify */
467         st->hand_state = (s->s3->tmp.cert_req == 1) ? TLS_ST_CW_CERT_VRFY
468                                                     : TLS_ST_CW_FINISHED;
469         return WRITE_TRAN_CONTINUE;
470 
471     case TLS_ST_CW_CERT_VRFY:
472         st->hand_state = TLS_ST_CW_FINISHED;
473         return WRITE_TRAN_CONTINUE;
474 
475     case TLS_ST_CR_KEY_UPDATE:
476     case TLS_ST_CW_KEY_UPDATE:
477     case TLS_ST_CR_SESSION_TICKET:
478     case TLS_ST_CW_FINISHED:
479         st->hand_state = TLS_ST_OK;
480         return WRITE_TRAN_CONTINUE;
481 
482     case TLS_ST_OK:
483         if (s->key_update != SSL_KEY_UPDATE_NONE) {
484             st->hand_state = TLS_ST_CW_KEY_UPDATE;
485             return WRITE_TRAN_CONTINUE;
486         }
487 
488         /* Try to read from the server instead */
489         return WRITE_TRAN_FINISHED;
490     }
491 }
492 
493 /*
494  * ossl_statem_client_write_transition() works out what handshake state to
495  * move to next when the client is writing messages to be sent to the server.
496  */
497 WRITE_TRAN ossl_statem_client_write_transition(SSL *s)
498 {
499     OSSL_STATEM *st = &s->statem;
500 
501     /*
502      * Note that immediately before/after a ClientHello we don't know what
503      * version we are going to negotiate yet, so we don't take this branch until
504      * later
505      */
506     if (SSL_IS_TLS13(s))
507         return ossl_statem_client13_write_transition(s);
508 
509     switch (st->hand_state) {
510     default:
511         /* Shouldn't happen */
512         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
513                  SSL_F_OSSL_STATEM_CLIENT_WRITE_TRANSITION,
514                  ERR_R_INTERNAL_ERROR);
515         return WRITE_TRAN_ERROR;
516 
517     case TLS_ST_OK:
518         if (!s->renegotiate) {
519             /*
520              * We haven't requested a renegotiation ourselves so we must have
521              * received a message from the server. Better read it.
522              */
523             return WRITE_TRAN_FINISHED;
524         }
525         /* Renegotiation */
526         /* fall thru */
527     case TLS_ST_BEFORE:
528         st->hand_state = TLS_ST_CW_CLNT_HELLO;
529         return WRITE_TRAN_CONTINUE;
530 
531     case TLS_ST_CW_CLNT_HELLO:
532         if (s->early_data_state == SSL_EARLY_DATA_CONNECTING) {
533             /*
534              * We are assuming this is a TLSv1.3 connection, although we haven't
535              * actually selected a version yet.
536              */
537             if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0)
538                 st->hand_state = TLS_ST_CW_CHANGE;
539             else
540                 st->hand_state = TLS_ST_EARLY_DATA;
541             return WRITE_TRAN_CONTINUE;
542         }
543         /*
544          * No transition at the end of writing because we don't know what
545          * we will be sent
546          */
547         return WRITE_TRAN_FINISHED;
548 
549     case TLS_ST_CR_SRVR_HELLO:
550         /*
551          * We only get here in TLSv1.3. We just received an HRR, so issue a
552          * CCS unless middlebox compat mode is off, or we already issued one
553          * because we did early data.
554          */
555         if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
556                 && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING)
557             st->hand_state = TLS_ST_CW_CHANGE;
558         else
559             st->hand_state = TLS_ST_CW_CLNT_HELLO;
560         return WRITE_TRAN_CONTINUE;
561 
562     case TLS_ST_EARLY_DATA:
563         return WRITE_TRAN_FINISHED;
564 
565     case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
566         st->hand_state = TLS_ST_CW_CLNT_HELLO;
567         return WRITE_TRAN_CONTINUE;
568 
569     case TLS_ST_CR_SRVR_DONE:
570         if (s->s3->tmp.cert_req)
571             st->hand_state = TLS_ST_CW_CERT;
572         else
573             st->hand_state = TLS_ST_CW_KEY_EXCH;
574         return WRITE_TRAN_CONTINUE;
575 
576     case TLS_ST_CW_CERT:
577         st->hand_state = TLS_ST_CW_KEY_EXCH;
578         return WRITE_TRAN_CONTINUE;
579 
580     case TLS_ST_CW_KEY_EXCH:
581         /*
582          * For TLS, cert_req is set to 2, so a cert chain of nothing is
583          * sent, but no verify packet is sent
584          */
585         /*
586          * XXX: For now, we do not support client authentication in ECDH
587          * cipher suites with ECDH (rather than ECDSA) certificates. We
588          * need to skip the certificate verify message when client's
589          * ECDH public key is sent inside the client certificate.
590          */
591         if (s->s3->tmp.cert_req == 1) {
592             st->hand_state = TLS_ST_CW_CERT_VRFY;
593         } else {
594             st->hand_state = TLS_ST_CW_CHANGE;
595         }
596         if (s->s3->flags & TLS1_FLAGS_SKIP_CERT_VERIFY) {
597             st->hand_state = TLS_ST_CW_CHANGE;
598         }
599         return WRITE_TRAN_CONTINUE;
600 
601     case TLS_ST_CW_CERT_VRFY:
602         st->hand_state = TLS_ST_CW_CHANGE;
603         return WRITE_TRAN_CONTINUE;
604 
605     case TLS_ST_CW_CHANGE:
606         if (s->hello_retry_request == SSL_HRR_PENDING) {
607             st->hand_state = TLS_ST_CW_CLNT_HELLO;
608         } else if (s->early_data_state == SSL_EARLY_DATA_CONNECTING) {
609             st->hand_state = TLS_ST_EARLY_DATA;
610         } else {
611 #if defined(OPENSSL_NO_NEXTPROTONEG)
612             st->hand_state = TLS_ST_CW_FINISHED;
613 #else
614             if (!SSL_IS_DTLS(s) && s->s3->npn_seen)
615                 st->hand_state = TLS_ST_CW_NEXT_PROTO;
616             else
617                 st->hand_state = TLS_ST_CW_FINISHED;
618 #endif
619         }
620         return WRITE_TRAN_CONTINUE;
621 
622 #if !defined(OPENSSL_NO_NEXTPROTONEG)
623     case TLS_ST_CW_NEXT_PROTO:
624         st->hand_state = TLS_ST_CW_FINISHED;
625         return WRITE_TRAN_CONTINUE;
626 #endif
627 
628     case TLS_ST_CW_FINISHED:
629         if (s->hit) {
630             st->hand_state = TLS_ST_OK;
631             return WRITE_TRAN_CONTINUE;
632         } else {
633             return WRITE_TRAN_FINISHED;
634         }
635 
636     case TLS_ST_CR_FINISHED:
637         if (s->hit) {
638             st->hand_state = TLS_ST_CW_CHANGE;
639             return WRITE_TRAN_CONTINUE;
640         } else {
641             st->hand_state = TLS_ST_OK;
642             return WRITE_TRAN_CONTINUE;
643         }
644 
645     case TLS_ST_CR_HELLO_REQ:
646         /*
647          * If we can renegotiate now then do so, otherwise wait for a more
648          * convenient time.
649          */
650         if (ssl3_renegotiate_check(s, 1)) {
651             if (!tls_setup_handshake(s)) {
652                 /* SSLfatal() already called */
653                 return WRITE_TRAN_ERROR;
654             }
655             st->hand_state = TLS_ST_CW_CLNT_HELLO;
656             return WRITE_TRAN_CONTINUE;
657         }
658         st->hand_state = TLS_ST_OK;
659         return WRITE_TRAN_CONTINUE;
660     }
661 }
662 
663 /*
664  * Perform any pre work that needs to be done prior to sending a message from
665  * the client to the server.
666  */
667 WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst)
668 {
669     OSSL_STATEM *st = &s->statem;
670 
671     switch (st->hand_state) {
672     default:
673         /* No pre work to be done */
674         break;
675 
676     case TLS_ST_CW_CLNT_HELLO:
677         s->shutdown = 0;
678         if (SSL_IS_DTLS(s)) {
679             /* every DTLS ClientHello resets Finished MAC */
680             if (!ssl3_init_finished_mac(s)) {
681                 /* SSLfatal() already called */
682                 return WORK_ERROR;
683             }
684         }
685         break;
686 
687     case TLS_ST_CW_CHANGE:
688         if (SSL_IS_DTLS(s)) {
689             if (s->hit) {
690                 /*
691                  * We're into the last flight so we don't retransmit these
692                  * messages unless we need to.
693                  */
694                 st->use_timer = 0;
695             }
696 #ifndef OPENSSL_NO_SCTP
697             if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
698                 /* Calls SSLfatal() as required */
699                 return dtls_wait_for_dry(s);
700             }
701 #endif
702         }
703         break;
704 
705     case TLS_ST_PENDING_EARLY_DATA_END:
706         /*
707          * If we've been called by SSL_do_handshake()/SSL_write(), or we did not
708          * attempt to write early data before calling SSL_read() then we press
709          * on with the handshake. Otherwise we pause here.
710          */
711         if (s->early_data_state == SSL_EARLY_DATA_FINISHED_WRITING
712                 || s->early_data_state == SSL_EARLY_DATA_NONE)
713             return WORK_FINISHED_CONTINUE;
714         /* Fall through */
715 
716     case TLS_ST_EARLY_DATA:
717         return tls_finish_handshake(s, wst, 0, 1);
718 
719     case TLS_ST_OK:
720         /* Calls SSLfatal() as required */
721         return tls_finish_handshake(s, wst, 1, 1);
722     }
723 
724     return WORK_FINISHED_CONTINUE;
725 }
726 
727 /*
728  * Perform any work that needs to be done after sending a message from the
729  * client to the server.
730  */
731 WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
732 {
733     OSSL_STATEM *st = &s->statem;
734 
735     s->init_num = 0;
736 
737     switch (st->hand_state) {
738     default:
739         /* No post work to be done */
740         break;
741 
742     case TLS_ST_CW_CLNT_HELLO:
743         if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
744                 && s->max_early_data > 0) {
745             /*
746              * We haven't selected TLSv1.3 yet so we don't call the change
747              * cipher state function associated with the SSL_METHOD. Instead
748              * we call tls13_change_cipher_state() directly.
749              */
750             if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) == 0) {
751                 if (!tls13_change_cipher_state(s,
752                             SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
753                     /* SSLfatal() already called */
754                     return WORK_ERROR;
755                 }
756             }
757             /* else we're in compat mode so we delay flushing until after CCS */
758         } else if (!statem_flush(s)) {
759             return WORK_MORE_A;
760         }
761 
762         if (SSL_IS_DTLS(s)) {
763             /* Treat the next message as the first packet */
764             s->first_packet = 1;
765         }
766         break;
767 
768     case TLS_ST_CW_END_OF_EARLY_DATA:
769         /*
770          * We set the enc_write_ctx back to NULL because we may end up writing
771          * in cleartext again if we get a HelloRetryRequest from the server.
772          */
773         EVP_CIPHER_CTX_free(s->enc_write_ctx);
774         s->enc_write_ctx = NULL;
775         break;
776 
777     case TLS_ST_CW_KEY_EXCH:
778         if (tls_client_key_exchange_post_work(s) == 0) {
779             /* SSLfatal() already called */
780             return WORK_ERROR;
781         }
782         break;
783 
784     case TLS_ST_CW_CHANGE:
785         if (SSL_IS_TLS13(s) || s->hello_retry_request == SSL_HRR_PENDING)
786             break;
787         if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
788                     && s->max_early_data > 0) {
789             /*
790              * We haven't selected TLSv1.3 yet so we don't call the change
791              * cipher state function associated with the SSL_METHOD. Instead
792              * we call tls13_change_cipher_state() directly.
793              */
794             if (!tls13_change_cipher_state(s,
795                         SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_CLIENT_WRITE))
796                 return WORK_ERROR;
797             break;
798         }
799         s->session->cipher = s->s3->tmp.new_cipher;
800 #ifdef OPENSSL_NO_COMP
801         s->session->compress_meth = 0;
802 #else
803         if (s->s3->tmp.new_compression == NULL)
804             s->session->compress_meth = 0;
805         else
806             s->session->compress_meth = s->s3->tmp.new_compression->id;
807 #endif
808         if (!s->method->ssl3_enc->setup_key_block(s)) {
809             /* SSLfatal() already called */
810             return WORK_ERROR;
811         }
812 
813         if (!s->method->ssl3_enc->change_cipher_state(s,
814                                           SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
815             /* SSLfatal() already called */
816             return WORK_ERROR;
817         }
818 
819         if (SSL_IS_DTLS(s)) {
820 #ifndef OPENSSL_NO_SCTP
821             if (s->hit) {
822                 /*
823                  * Change to new shared key of SCTP-Auth, will be ignored if
824                  * no SCTP used.
825                  */
826                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
827                          0, NULL);
828             }
829 #endif
830 
831             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
832         }
833         break;
834 
835     case TLS_ST_CW_FINISHED:
836 #ifndef OPENSSL_NO_SCTP
837         if (wst == WORK_MORE_A && SSL_IS_DTLS(s) && s->hit == 0) {
838             /*
839              * Change to new shared key of SCTP-Auth, will be ignored if
840              * no SCTP used.
841              */
842             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
843                      0, NULL);
844         }
845 #endif
846         if (statem_flush(s) != 1)
847             return WORK_MORE_B;
848 
849         if (SSL_IS_TLS13(s)) {
850             if (!tls13_save_handshake_digest_for_pha(s)) {
851                 /* SSLfatal() already called */
852                 return WORK_ERROR;
853             }
854             if (s->post_handshake_auth != SSL_PHA_REQUESTED) {
855                 if (!s->method->ssl3_enc->change_cipher_state(s,
856                         SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
857                     /* SSLfatal() already called */
858                     return WORK_ERROR;
859                 }
860             }
861         }
862         break;
863 
864     case TLS_ST_CW_KEY_UPDATE:
865         if (statem_flush(s) != 1)
866             return WORK_MORE_A;
867         if (!tls13_update_key(s, 1)) {
868             /* SSLfatal() already called */
869             return WORK_ERROR;
870         }
871         break;
872     }
873 
874     return WORK_FINISHED_CONTINUE;
875 }
876 
877 /*
878  * Get the message construction function and message type for sending from the
879  * client
880  *
881  * Valid return values are:
882  *   1: Success
883  *   0: Error
884  */
885 int ossl_statem_client_construct_message(SSL *s, WPACKET *pkt,
886                                          confunc_f *confunc, int *mt)
887 {
888     OSSL_STATEM *st = &s->statem;
889 
890     switch (st->hand_state) {
891     default:
892         /* Shouldn't happen */
893         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
894                  SSL_F_OSSL_STATEM_CLIENT_CONSTRUCT_MESSAGE,
895                  SSL_R_BAD_HANDSHAKE_STATE);
896         return 0;
897 
898     case TLS_ST_CW_CHANGE:
899         if (SSL_IS_DTLS(s))
900             *confunc = dtls_construct_change_cipher_spec;
901         else
902             *confunc = tls_construct_change_cipher_spec;
903         *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
904         break;
905 
906     case TLS_ST_CW_CLNT_HELLO:
907         *confunc = tls_construct_client_hello;
908         *mt = SSL3_MT_CLIENT_HELLO;
909         break;
910 
911     case TLS_ST_CW_END_OF_EARLY_DATA:
912         *confunc = tls_construct_end_of_early_data;
913         *mt = SSL3_MT_END_OF_EARLY_DATA;
914         break;
915 
916     case TLS_ST_PENDING_EARLY_DATA_END:
917         *confunc = NULL;
918         *mt = SSL3_MT_DUMMY;
919         break;
920 
921     case TLS_ST_CW_CERT:
922         *confunc = tls_construct_client_certificate;
923         *mt = SSL3_MT_CERTIFICATE;
924         break;
925 
926     case TLS_ST_CW_KEY_EXCH:
927         *confunc = tls_construct_client_key_exchange;
928         *mt = SSL3_MT_CLIENT_KEY_EXCHANGE;
929         break;
930 
931     case TLS_ST_CW_CERT_VRFY:
932         *confunc = tls_construct_cert_verify;
933         *mt = SSL3_MT_CERTIFICATE_VERIFY;
934         break;
935 
936 #if !defined(OPENSSL_NO_NEXTPROTONEG)
937     case TLS_ST_CW_NEXT_PROTO:
938         *confunc = tls_construct_next_proto;
939         *mt = SSL3_MT_NEXT_PROTO;
940         break;
941 #endif
942     case TLS_ST_CW_FINISHED:
943         *confunc = tls_construct_finished;
944         *mt = SSL3_MT_FINISHED;
945         break;
946 
947     case TLS_ST_CW_KEY_UPDATE:
948         *confunc = tls_construct_key_update;
949         *mt = SSL3_MT_KEY_UPDATE;
950         break;
951     }
952 
953     return 1;
954 }
955 
956 /*
957  * Returns the maximum allowed length for the current message that we are
958  * reading. Excludes the message header.
959  */
960 size_t ossl_statem_client_max_message_size(SSL *s)
961 {
962     OSSL_STATEM *st = &s->statem;
963 
964     switch (st->hand_state) {
965     default:
966         /* Shouldn't happen */
967         return 0;
968 
969     case TLS_ST_CR_SRVR_HELLO:
970         return SERVER_HELLO_MAX_LENGTH;
971 
972     case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
973         return HELLO_VERIFY_REQUEST_MAX_LENGTH;
974 
975     case TLS_ST_CR_CERT:
976         return s->max_cert_list;
977 
978     case TLS_ST_CR_CERT_VRFY:
979         return SSL3_RT_MAX_PLAIN_LENGTH;
980 
981     case TLS_ST_CR_CERT_STATUS:
982         return SSL3_RT_MAX_PLAIN_LENGTH;
983 
984     case TLS_ST_CR_KEY_EXCH:
985         return SERVER_KEY_EXCH_MAX_LENGTH;
986 
987     case TLS_ST_CR_CERT_REQ:
988         /*
989          * Set to s->max_cert_list for compatibility with previous releases. In
990          * practice these messages can get quite long if servers are configured
991          * to provide a long list of acceptable CAs
992          */
993         return s->max_cert_list;
994 
995     case TLS_ST_CR_SRVR_DONE:
996         return SERVER_HELLO_DONE_MAX_LENGTH;
997 
998     case TLS_ST_CR_CHANGE:
999         if (s->version == DTLS1_BAD_VER)
1000             return 3;
1001         return CCS_MAX_LENGTH;
1002 
1003     case TLS_ST_CR_SESSION_TICKET:
1004         return (SSL_IS_TLS13(s)) ? SESSION_TICKET_MAX_LENGTH_TLS13
1005                                  : SESSION_TICKET_MAX_LENGTH_TLS12;
1006 
1007     case TLS_ST_CR_FINISHED:
1008         return FINISHED_MAX_LENGTH;
1009 
1010     case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
1011         return ENCRYPTED_EXTENSIONS_MAX_LENGTH;
1012 
1013     case TLS_ST_CR_KEY_UPDATE:
1014         return KEY_UPDATE_MAX_LENGTH;
1015     }
1016 }
1017 
1018 /*
1019  * Process a message that the client has been received from the server.
1020  */
1021 MSG_PROCESS_RETURN ossl_statem_client_process_message(SSL *s, PACKET *pkt)
1022 {
1023     OSSL_STATEM *st = &s->statem;
1024 
1025     switch (st->hand_state) {
1026     default:
1027         /* Shouldn't happen */
1028         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1029                  SSL_F_OSSL_STATEM_CLIENT_PROCESS_MESSAGE,
1030                  ERR_R_INTERNAL_ERROR);
1031         return MSG_PROCESS_ERROR;
1032 
1033     case TLS_ST_CR_SRVR_HELLO:
1034         return tls_process_server_hello(s, pkt);
1035 
1036     case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
1037         return dtls_process_hello_verify(s, pkt);
1038 
1039     case TLS_ST_CR_CERT:
1040         return tls_process_server_certificate(s, pkt);
1041 
1042     case TLS_ST_CR_CERT_VRFY:
1043         return tls_process_cert_verify(s, pkt);
1044 
1045     case TLS_ST_CR_CERT_STATUS:
1046         return tls_process_cert_status(s, pkt);
1047 
1048     case TLS_ST_CR_KEY_EXCH:
1049         return tls_process_key_exchange(s, pkt);
1050 
1051     case TLS_ST_CR_CERT_REQ:
1052         return tls_process_certificate_request(s, pkt);
1053 
1054     case TLS_ST_CR_SRVR_DONE:
1055         return tls_process_server_done(s, pkt);
1056 
1057     case TLS_ST_CR_CHANGE:
1058         return tls_process_change_cipher_spec(s, pkt);
1059 
1060     case TLS_ST_CR_SESSION_TICKET:
1061         return tls_process_new_session_ticket(s, pkt);
1062 
1063     case TLS_ST_CR_FINISHED:
1064         return tls_process_finished(s, pkt);
1065 
1066     case TLS_ST_CR_HELLO_REQ:
1067         return tls_process_hello_req(s, pkt);
1068 
1069     case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
1070         return tls_process_encrypted_extensions(s, pkt);
1071 
1072     case TLS_ST_CR_KEY_UPDATE:
1073         return tls_process_key_update(s, pkt);
1074     }
1075 }
1076 
1077 /*
1078  * Perform any further processing required following the receipt of a message
1079  * from the server
1080  */
1081 WORK_STATE ossl_statem_client_post_process_message(SSL *s, WORK_STATE wst)
1082 {
1083     OSSL_STATEM *st = &s->statem;
1084 
1085     switch (st->hand_state) {
1086     default:
1087         /* Shouldn't happen */
1088         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1089                  SSL_F_OSSL_STATEM_CLIENT_POST_PROCESS_MESSAGE,
1090                  ERR_R_INTERNAL_ERROR);
1091         return WORK_ERROR;
1092 
1093     case TLS_ST_CR_CERT_VRFY:
1094     case TLS_ST_CR_CERT_REQ:
1095         return tls_prepare_client_certificate(s, wst);
1096     }
1097 }
1098 
1099 int tls_construct_client_hello(SSL *s, WPACKET *pkt)
1100 {
1101     unsigned char *p;
1102     size_t sess_id_len;
1103     int i, protverr;
1104 #ifndef OPENSSL_NO_COMP
1105     SSL_COMP *comp;
1106 #endif
1107     SSL_SESSION *sess = s->session;
1108     unsigned char *session_id;
1109 
1110     /* Work out what SSL/TLS/DTLS version to use */
1111     protverr = ssl_set_client_hello_version(s);
1112     if (protverr != 0) {
1113         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1114                  protverr);
1115         return 0;
1116     }
1117 
1118     if (sess == NULL
1119             || !ssl_version_supported(s, sess->ssl_version, NULL)
1120             || !SSL_SESSION_is_resumable(sess)) {
1121         if (s->hello_retry_request == SSL_HRR_NONE
1122                 && !ssl_get_new_session(s, 0)) {
1123             /* SSLfatal() already called */
1124             return 0;
1125         }
1126     }
1127     /* else use the pre-loaded session */
1128 
1129     p = s->s3->client_random;
1130 
1131     /*
1132      * for DTLS if client_random is initialized, reuse it, we are
1133      * required to use same upon reply to HelloVerify
1134      */
1135     if (SSL_IS_DTLS(s)) {
1136         size_t idx;
1137         i = 1;
1138         for (idx = 0; idx < sizeof(s->s3->client_random); idx++) {
1139             if (p[idx]) {
1140                 i = 0;
1141                 break;
1142             }
1143         }
1144     } else {
1145         i = (s->hello_retry_request == SSL_HRR_NONE);
1146     }
1147 
1148     if (i && ssl_fill_hello_random(s, 0, p, sizeof(s->s3->client_random),
1149                                    DOWNGRADE_NONE) <= 0) {
1150         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1151                  ERR_R_INTERNAL_ERROR);
1152         return 0;
1153     }
1154 
1155     /*-
1156      * version indicates the negotiated version: for example from
1157      * an SSLv2/v3 compatible client hello). The client_version
1158      * field is the maximum version we permit and it is also
1159      * used in RSA encrypted premaster secrets. Some servers can
1160      * choke if we initially report a higher version then
1161      * renegotiate to a lower one in the premaster secret. This
1162      * didn't happen with TLS 1.0 as most servers supported it
1163      * but it can with TLS 1.1 or later if the server only supports
1164      * 1.0.
1165      *
1166      * Possible scenario with previous logic:
1167      *      1. Client hello indicates TLS 1.2
1168      *      2. Server hello says TLS 1.0
1169      *      3. RSA encrypted premaster secret uses 1.2.
1170      *      4. Handshake proceeds using TLS 1.0.
1171      *      5. Server sends hello request to renegotiate.
1172      *      6. Client hello indicates TLS v1.0 as we now
1173      *         know that is maximum server supports.
1174      *      7. Server chokes on RSA encrypted premaster secret
1175      *         containing version 1.0.
1176      *
1177      * For interoperability it should be OK to always use the
1178      * maximum version we support in client hello and then rely
1179      * on the checking of version to ensure the servers isn't
1180      * being inconsistent: for example initially negotiating with
1181      * TLS 1.0 and renegotiating with TLS 1.2. We do this by using
1182      * client_version in client hello and not resetting it to
1183      * the negotiated version.
1184      *
1185      * For TLS 1.3 we always set the ClientHello version to 1.2 and rely on the
1186      * supported_versions extension for the real supported versions.
1187      */
1188     if (!WPACKET_put_bytes_u16(pkt, s->client_version)
1189             || !WPACKET_memcpy(pkt, s->s3->client_random, SSL3_RANDOM_SIZE)) {
1190         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1191                  ERR_R_INTERNAL_ERROR);
1192         return 0;
1193     }
1194 
1195     /* Session ID */
1196     session_id = s->session->session_id;
1197     if (s->new_session || s->session->ssl_version == TLS1_3_VERSION) {
1198         if (s->version == TLS1_3_VERSION
1199                 && (s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0) {
1200             sess_id_len = sizeof(s->tmp_session_id);
1201             s->tmp_session_id_len = sess_id_len;
1202             session_id = s->tmp_session_id;
1203             if (s->hello_retry_request == SSL_HRR_NONE
1204                     && RAND_bytes(s->tmp_session_id, sess_id_len) <= 0) {
1205                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1206                          SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1207                          ERR_R_INTERNAL_ERROR);
1208                 return 0;
1209             }
1210         } else {
1211             sess_id_len = 0;
1212         }
1213     } else {
1214         assert(s->session->session_id_length <= sizeof(s->session->session_id));
1215         sess_id_len = s->session->session_id_length;
1216         if (s->version == TLS1_3_VERSION) {
1217             s->tmp_session_id_len = sess_id_len;
1218             memcpy(s->tmp_session_id, s->session->session_id, sess_id_len);
1219         }
1220     }
1221     if (!WPACKET_start_sub_packet_u8(pkt)
1222             || (sess_id_len != 0 && !WPACKET_memcpy(pkt, session_id,
1223                                                     sess_id_len))
1224             || !WPACKET_close(pkt)) {
1225         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1226                  ERR_R_INTERNAL_ERROR);
1227         return 0;
1228     }
1229 
1230     /* cookie stuff for DTLS */
1231     if (SSL_IS_DTLS(s)) {
1232         if (s->d1->cookie_len > sizeof(s->d1->cookie)
1233                 || !WPACKET_sub_memcpy_u8(pkt, s->d1->cookie,
1234                                           s->d1->cookie_len)) {
1235             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1236                      ERR_R_INTERNAL_ERROR);
1237             return 0;
1238         }
1239     }
1240 
1241     /* Ciphers supported */
1242     if (!WPACKET_start_sub_packet_u16(pkt)) {
1243         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1244                  ERR_R_INTERNAL_ERROR);
1245         return 0;
1246     }
1247 
1248     if (!ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), pkt)) {
1249         /* SSLfatal() already called */
1250         return 0;
1251     }
1252     if (!WPACKET_close(pkt)) {
1253         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1254                  ERR_R_INTERNAL_ERROR);
1255         return 0;
1256     }
1257 
1258     /* COMPRESSION */
1259     if (!WPACKET_start_sub_packet_u8(pkt)) {
1260         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1261                  ERR_R_INTERNAL_ERROR);
1262         return 0;
1263     }
1264 #ifndef OPENSSL_NO_COMP
1265     if (ssl_allow_compression(s)
1266             && s->ctx->comp_methods
1267             && (SSL_IS_DTLS(s) || s->s3->tmp.max_ver < TLS1_3_VERSION)) {
1268         int compnum = sk_SSL_COMP_num(s->ctx->comp_methods);
1269         for (i = 0; i < compnum; i++) {
1270             comp = sk_SSL_COMP_value(s->ctx->comp_methods, i);
1271             if (!WPACKET_put_bytes_u8(pkt, comp->id)) {
1272                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1273                          SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1274                          ERR_R_INTERNAL_ERROR);
1275                 return 0;
1276             }
1277         }
1278     }
1279 #endif
1280     /* Add the NULL method */
1281     if (!WPACKET_put_bytes_u8(pkt, 0) || !WPACKET_close(pkt)) {
1282         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1283                  ERR_R_INTERNAL_ERROR);
1284         return 0;
1285     }
1286 
1287     /* TLS extensions */
1288     if (!tls_construct_extensions(s, pkt, SSL_EXT_CLIENT_HELLO, NULL, 0)) {
1289         /* SSLfatal() already called */
1290         return 0;
1291     }
1292 
1293     return 1;
1294 }
1295 
1296 MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s, PACKET *pkt)
1297 {
1298     size_t cookie_len;
1299     PACKET cookiepkt;
1300 
1301     if (!PACKET_forward(pkt, 2)
1302         || !PACKET_get_length_prefixed_1(pkt, &cookiepkt)) {
1303         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
1304                  SSL_R_LENGTH_MISMATCH);
1305         return MSG_PROCESS_ERROR;
1306     }
1307 
1308     cookie_len = PACKET_remaining(&cookiepkt);
1309     if (cookie_len > sizeof(s->d1->cookie)) {
1310         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
1311                  SSL_R_LENGTH_TOO_LONG);
1312         return MSG_PROCESS_ERROR;
1313     }
1314 
1315     if (!PACKET_copy_bytes(&cookiepkt, s->d1->cookie, cookie_len)) {
1316         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
1317                  SSL_R_LENGTH_MISMATCH);
1318         return MSG_PROCESS_ERROR;
1319     }
1320     s->d1->cookie_len = cookie_len;
1321 
1322     return MSG_PROCESS_FINISHED_READING;
1323 }
1324 
1325 static int set_client_ciphersuite(SSL *s, const unsigned char *cipherchars)
1326 {
1327     STACK_OF(SSL_CIPHER) *sk;
1328     const SSL_CIPHER *c;
1329     int i;
1330 
1331     c = ssl_get_cipher_by_char(s, cipherchars, 0);
1332     if (c == NULL) {
1333         /* unknown cipher */
1334         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1335                  SSL_R_UNKNOWN_CIPHER_RETURNED);
1336         return 0;
1337     }
1338     /*
1339      * If it is a disabled cipher we either didn't send it in client hello,
1340      * or it's not allowed for the selected protocol. So we return an error.
1341      */
1342     if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_CHECK, 1)) {
1343         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1344                  SSL_R_WRONG_CIPHER_RETURNED);
1345         return 0;
1346     }
1347 
1348     sk = ssl_get_ciphers_by_id(s);
1349     i = sk_SSL_CIPHER_find(sk, c);
1350     if (i < 0) {
1351         /* we did not say we would use this cipher */
1352         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1353                  SSL_R_WRONG_CIPHER_RETURNED);
1354         return 0;
1355     }
1356 
1357     if (SSL_IS_TLS13(s) && s->s3->tmp.new_cipher != NULL
1358             && s->s3->tmp.new_cipher->id != c->id) {
1359         /* ServerHello selected a different ciphersuite to that in the HRR */
1360         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1361                  SSL_R_WRONG_CIPHER_RETURNED);
1362         return 0;
1363     }
1364 
1365     /*
1366      * Depending on the session caching (internal/external), the cipher
1367      * and/or cipher_id values may not be set. Make sure that cipher_id is
1368      * set and use it for comparison.
1369      */
1370     if (s->session->cipher != NULL)
1371         s->session->cipher_id = s->session->cipher->id;
1372     if (s->hit && (s->session->cipher_id != c->id)) {
1373         if (SSL_IS_TLS13(s)) {
1374             /*
1375              * In TLSv1.3 it is valid for the server to select a different
1376              * ciphersuite as long as the hash is the same.
1377              */
1378             if (ssl_md(c->algorithm2)
1379                     != ssl_md(s->session->cipher->algorithm2)) {
1380                 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1381                          SSL_F_SET_CLIENT_CIPHERSUITE,
1382                          SSL_R_CIPHERSUITE_DIGEST_HAS_CHANGED);
1383                 return 0;
1384             }
1385         } else {
1386             /*
1387              * Prior to TLSv1.3 resuming a session always meant using the same
1388              * ciphersuite.
1389              */
1390             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1391                      SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
1392             return 0;
1393         }
1394     }
1395     s->s3->tmp.new_cipher = c;
1396 
1397     return 1;
1398 }
1399 
1400 MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
1401 {
1402     PACKET session_id, extpkt;
1403     size_t session_id_len;
1404     const unsigned char *cipherchars;
1405     int hrr = 0;
1406     unsigned int compression;
1407     unsigned int sversion;
1408     unsigned int context;
1409     RAW_EXTENSION *extensions = NULL;
1410 #ifndef OPENSSL_NO_COMP
1411     SSL_COMP *comp;
1412 #endif
1413 
1414     if (!PACKET_get_net_2(pkt, &sversion)) {
1415         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1416                  SSL_R_LENGTH_MISMATCH);
1417         goto err;
1418     }
1419 
1420     /* load the server random */
1421     if (s->version == TLS1_3_VERSION
1422             && sversion == TLS1_2_VERSION
1423             && PACKET_remaining(pkt) >= SSL3_RANDOM_SIZE
1424             && memcmp(hrrrandom, PACKET_data(pkt), SSL3_RANDOM_SIZE) == 0) {
1425         s->hello_retry_request = SSL_HRR_PENDING;
1426         hrr = 1;
1427         if (!PACKET_forward(pkt, SSL3_RANDOM_SIZE)) {
1428             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1429                      SSL_R_LENGTH_MISMATCH);
1430             goto err;
1431         }
1432     } else {
1433         if (!PACKET_copy_bytes(pkt, s->s3->server_random, SSL3_RANDOM_SIZE)) {
1434             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1435                      SSL_R_LENGTH_MISMATCH);
1436             goto err;
1437         }
1438     }
1439 
1440     /* Get the session-id. */
1441     if (!PACKET_get_length_prefixed_1(pkt, &session_id)) {
1442         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1443                  SSL_R_LENGTH_MISMATCH);
1444         goto err;
1445     }
1446     session_id_len = PACKET_remaining(&session_id);
1447     if (session_id_len > sizeof(s->session->session_id)
1448         || session_id_len > SSL3_SESSION_ID_SIZE) {
1449         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1450                  SSL_R_SSL3_SESSION_ID_TOO_LONG);
1451         goto err;
1452     }
1453 
1454     if (!PACKET_get_bytes(pkt, &cipherchars, TLS_CIPHER_LEN)) {
1455         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1456                  SSL_R_LENGTH_MISMATCH);
1457         goto err;
1458     }
1459 
1460     if (!PACKET_get_1(pkt, &compression)) {
1461         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1462                  SSL_R_LENGTH_MISMATCH);
1463         goto err;
1464     }
1465 
1466     /* TLS extensions */
1467     if (PACKET_remaining(pkt) == 0 && !hrr) {
1468         PACKET_null_init(&extpkt);
1469     } else if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
1470                || PACKET_remaining(pkt) != 0) {
1471         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1472                  SSL_R_BAD_LENGTH);
1473         goto err;
1474     }
1475 
1476     if (!hrr) {
1477         if (!tls_collect_extensions(s, &extpkt,
1478                                     SSL_EXT_TLS1_2_SERVER_HELLO
1479                                     | SSL_EXT_TLS1_3_SERVER_HELLO,
1480                                     &extensions, NULL, 1)) {
1481             /* SSLfatal() already called */
1482             goto err;
1483         }
1484 
1485         if (!ssl_choose_client_version(s, sversion, extensions)) {
1486             /* SSLfatal() already called */
1487             goto err;
1488         }
1489     }
1490 
1491     if (SSL_IS_TLS13(s) || hrr) {
1492         if (compression != 0) {
1493             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1494                      SSL_F_TLS_PROCESS_SERVER_HELLO,
1495                      SSL_R_INVALID_COMPRESSION_ALGORITHM);
1496             goto err;
1497         }
1498 
1499         if (session_id_len != s->tmp_session_id_len
1500                 || memcmp(PACKET_data(&session_id), s->tmp_session_id,
1501                           session_id_len) != 0) {
1502             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1503                      SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_INVALID_SESSION_ID);
1504             goto err;
1505         }
1506     }
1507 
1508     if (hrr) {
1509         if (!set_client_ciphersuite(s, cipherchars)) {
1510             /* SSLfatal() already called */
1511             goto err;
1512         }
1513 
1514         return tls_process_as_hello_retry_request(s, &extpkt);
1515     }
1516 
1517     /*
1518      * Now we have chosen the version we need to check again that the extensions
1519      * are appropriate for this version.
1520      */
1521     context = SSL_IS_TLS13(s) ? SSL_EXT_TLS1_3_SERVER_HELLO
1522                               : SSL_EXT_TLS1_2_SERVER_HELLO;
1523     if (!tls_validate_all_contexts(s, context, extensions)) {
1524         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1525                  SSL_R_BAD_EXTENSION);
1526         goto err;
1527     }
1528 
1529     s->hit = 0;
1530 
1531     if (SSL_IS_TLS13(s)) {
1532         /*
1533          * In TLSv1.3 a ServerHello message signals a key change so the end of
1534          * the message must be on a record boundary.
1535          */
1536         if (RECORD_LAYER_processed_read_pending(&s->rlayer)) {
1537             SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
1538                      SSL_F_TLS_PROCESS_SERVER_HELLO,
1539                      SSL_R_NOT_ON_RECORD_BOUNDARY);
1540             goto err;
1541         }
1542 
1543         /* This will set s->hit if we are resuming */
1544         if (!tls_parse_extension(s, TLSEXT_IDX_psk,
1545                                  SSL_EXT_TLS1_3_SERVER_HELLO,
1546                                  extensions, NULL, 0)) {
1547             /* SSLfatal() already called */
1548             goto err;
1549         }
1550     } else {
1551         /*
1552          * Check if we can resume the session based on external pre-shared
1553          * secret. EAP-FAST (RFC 4851) supports two types of session resumption.
1554          * Resumption based on server-side state works with session IDs.
1555          * Resumption based on pre-shared Protected Access Credentials (PACs)
1556          * works by overriding the SessionTicket extension at the application
1557          * layer, and does not send a session ID. (We do not know whether
1558          * EAP-FAST servers would honour the session ID.) Therefore, the session
1559          * ID alone is not a reliable indicator of session resumption, so we
1560          * first check if we can resume, and later peek at the next handshake
1561          * message to see if the server wants to resume.
1562          */
1563         if (s->version >= TLS1_VERSION
1564                 && s->ext.session_secret_cb != NULL && s->session->ext.tick) {
1565             const SSL_CIPHER *pref_cipher = NULL;
1566             /*
1567              * s->session->master_key_length is a size_t, but this is an int for
1568              * backwards compat reasons
1569              */
1570             int master_key_length;
1571             master_key_length = sizeof(s->session->master_key);
1572             if (s->ext.session_secret_cb(s, s->session->master_key,
1573                                          &master_key_length,
1574                                          NULL, &pref_cipher,
1575                                          s->ext.session_secret_cb_arg)
1576                      && master_key_length > 0) {
1577                 s->session->master_key_length = master_key_length;
1578                 s->session->cipher = pref_cipher ?
1579                     pref_cipher : ssl_get_cipher_by_char(s, cipherchars, 0);
1580             } else {
1581                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1582                          SSL_F_TLS_PROCESS_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
1583                 goto err;
1584             }
1585         }
1586 
1587         if (session_id_len != 0
1588                 && session_id_len == s->session->session_id_length
1589                 && memcmp(PACKET_data(&session_id), s->session->session_id,
1590                           session_id_len) == 0)
1591             s->hit = 1;
1592     }
1593 
1594     if (s->hit) {
1595         if (s->sid_ctx_length != s->session->sid_ctx_length
1596                 || memcmp(s->session->sid_ctx, s->sid_ctx, s->sid_ctx_length)) {
1597             /* actually a client application bug */
1598             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1599                      SSL_F_TLS_PROCESS_SERVER_HELLO,
1600                      SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
1601             goto err;
1602         }
1603     } else {
1604         /*
1605          * If we were trying for session-id reuse but the server
1606          * didn't resume, make a new SSL_SESSION.
1607          * In the case of EAP-FAST and PAC, we do not send a session ID,
1608          * so the PAC-based session secret is always preserved. It'll be
1609          * overwritten if the server refuses resumption.
1610          */
1611         if (s->session->session_id_length > 0) {
1612             tsan_counter(&s->session_ctx->stats.sess_miss);
1613             if (!ssl_get_new_session(s, 0)) {
1614                 /* SSLfatal() already called */
1615                 goto err;
1616             }
1617         }
1618 
1619         s->session->ssl_version = s->version;
1620         /*
1621          * In TLSv1.2 and below we save the session id we were sent so we can
1622          * resume it later. In TLSv1.3 the session id we were sent is just an
1623          * echo of what we originally sent in the ClientHello and should not be
1624          * used for resumption.
1625          */
1626         if (!SSL_IS_TLS13(s)) {
1627             s->session->session_id_length = session_id_len;
1628             /* session_id_len could be 0 */
1629             if (session_id_len > 0)
1630                 memcpy(s->session->session_id, PACKET_data(&session_id),
1631                        session_id_len);
1632         }
1633     }
1634 
1635     /* Session version and negotiated protocol version should match */
1636     if (s->version != s->session->ssl_version) {
1637         SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_TLS_PROCESS_SERVER_HELLO,
1638                  SSL_R_SSL_SESSION_VERSION_MISMATCH);
1639         goto err;
1640     }
1641     /*
1642      * Now that we know the version, update the check to see if it's an allowed
1643      * version.
1644      */
1645     s->s3->tmp.min_ver = s->version;
1646     s->s3->tmp.max_ver = s->version;
1647 
1648     if (!set_client_ciphersuite(s, cipherchars)) {
1649         /* SSLfatal() already called */
1650         goto err;
1651     }
1652 
1653 #ifdef OPENSSL_NO_COMP
1654     if (compression != 0) {
1655         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1656                  SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
1657         goto err;
1658     }
1659     /*
1660      * If compression is disabled we'd better not try to resume a session
1661      * using compression.
1662      */
1663     if (s->session->compress_meth != 0) {
1664         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SERVER_HELLO,
1665                  SSL_R_INCONSISTENT_COMPRESSION);
1666         goto err;
1667     }
1668 #else
1669     if (s->hit && compression != s->session->compress_meth) {
1670         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1671                  SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
1672         goto err;
1673     }
1674     if (compression == 0)
1675         comp = NULL;
1676     else if (!ssl_allow_compression(s)) {
1677         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1678                  SSL_R_COMPRESSION_DISABLED);
1679         goto err;
1680     } else {
1681         comp = ssl3_comp_find(s->ctx->comp_methods, compression);
1682     }
1683 
1684     if (compression != 0 && comp == NULL) {
1685         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1686                  SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
1687         goto err;
1688     } else {
1689         s->s3->tmp.new_compression = comp;
1690     }
1691 #endif
1692 
1693     if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, 1)) {
1694         /* SSLfatal() already called */
1695         goto err;
1696     }
1697 
1698 #ifndef OPENSSL_NO_SCTP
1699     if (SSL_IS_DTLS(s) && s->hit) {
1700         unsigned char sctpauthkey[64];
1701         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
1702         size_t labellen;
1703 
1704         /*
1705          * Add new shared key for SCTP-Auth, will be ignored if
1706          * no SCTP used.
1707          */
1708         memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
1709                sizeof(DTLS1_SCTP_AUTH_LABEL));
1710 
1711         /* Don't include the terminating zero. */
1712         labellen = sizeof(labelbuffer) - 1;
1713         if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
1714             labellen += 1;
1715 
1716         if (SSL_export_keying_material(s, sctpauthkey,
1717                                        sizeof(sctpauthkey),
1718                                        labelbuffer,
1719                                        labellen, NULL, 0, 0) <= 0) {
1720             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1721                      ERR_R_INTERNAL_ERROR);
1722             goto err;
1723         }
1724 
1725         BIO_ctrl(SSL_get_wbio(s),
1726                  BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
1727                  sizeof(sctpauthkey), sctpauthkey);
1728     }
1729 #endif
1730 
1731     /*
1732      * In TLSv1.3 we have some post-processing to change cipher state, otherwise
1733      * we're done with this message
1734      */
1735     if (SSL_IS_TLS13(s)
1736             && (!s->method->ssl3_enc->setup_key_block(s)
1737                 || !s->method->ssl3_enc->change_cipher_state(s,
1738                     SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_READ))) {
1739         /* SSLfatal() already called */
1740         goto err;
1741     }
1742 
1743     OPENSSL_free(extensions);
1744     return MSG_PROCESS_CONTINUE_READING;
1745  err:
1746     OPENSSL_free(extensions);
1747     return MSG_PROCESS_ERROR;
1748 }
1749 
1750 static MSG_PROCESS_RETURN tls_process_as_hello_retry_request(SSL *s,
1751                                                              PACKET *extpkt)
1752 {
1753     RAW_EXTENSION *extensions = NULL;
1754 
1755     /*
1756      * If we were sending early_data then the enc_write_ctx is now invalid and
1757      * should not be used.
1758      */
1759     EVP_CIPHER_CTX_free(s->enc_write_ctx);
1760     s->enc_write_ctx = NULL;
1761 
1762     if (!tls_collect_extensions(s, extpkt, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
1763                                 &extensions, NULL, 1)
1764             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
1765                                          extensions, NULL, 0, 1)) {
1766         /* SSLfatal() already called */
1767         goto err;
1768     }
1769 
1770     OPENSSL_free(extensions);
1771     extensions = NULL;
1772 
1773     if (s->ext.tls13_cookie_len == 0
1774 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
1775         && s->s3->tmp.pkey != NULL
1776 #endif
1777         ) {
1778         /*
1779          * We didn't receive a cookie or a new key_share so the next
1780          * ClientHello will not change
1781          */
1782         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1783                  SSL_F_TLS_PROCESS_AS_HELLO_RETRY_REQUEST,
1784                  SSL_R_NO_CHANGE_FOLLOWING_HRR);
1785         goto err;
1786     }
1787 
1788     /*
1789      * Re-initialise the Transcript Hash. We're going to prepopulate it with
1790      * a synthetic message_hash in place of ClientHello1.
1791      */
1792     if (!create_synthetic_message_hash(s, NULL, 0, NULL, 0)) {
1793         /* SSLfatal() already called */
1794         goto err;
1795     }
1796 
1797     /*
1798      * Add this message to the Transcript Hash. Normally this is done
1799      * automatically prior to the message processing stage. However due to the
1800      * need to create the synthetic message hash, we defer that step until now
1801      * for HRR messages.
1802      */
1803     if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
1804                                 s->init_num + SSL3_HM_HEADER_LENGTH)) {
1805         /* SSLfatal() already called */
1806         goto err;
1807     }
1808 
1809     return MSG_PROCESS_FINISHED_READING;
1810  err:
1811     OPENSSL_free(extensions);
1812     return MSG_PROCESS_ERROR;
1813 }
1814 
1815 MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
1816 {
1817     int i;
1818     MSG_PROCESS_RETURN ret = MSG_PROCESS_ERROR;
1819     unsigned long cert_list_len, cert_len;
1820     X509 *x = NULL;
1821     const unsigned char *certstart, *certbytes;
1822     STACK_OF(X509) *sk = NULL;
1823     EVP_PKEY *pkey = NULL;
1824     size_t chainidx, certidx;
1825     unsigned int context = 0;
1826     const SSL_CERT_LOOKUP *clu;
1827 
1828     if ((sk = sk_X509_new_null()) == NULL) {
1829         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1830                  ERR_R_MALLOC_FAILURE);
1831         goto err;
1832     }
1833 
1834     if ((SSL_IS_TLS13(s) && !PACKET_get_1(pkt, &context))
1835             || context != 0
1836             || !PACKET_get_net_3(pkt, &cert_list_len)
1837             || PACKET_remaining(pkt) != cert_list_len
1838             || PACKET_remaining(pkt) == 0) {
1839         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1840                  SSL_R_LENGTH_MISMATCH);
1841         goto err;
1842     }
1843     for (chainidx = 0; PACKET_remaining(pkt); chainidx++) {
1844         if (!PACKET_get_net_3(pkt, &cert_len)
1845             || !PACKET_get_bytes(pkt, &certbytes, cert_len)) {
1846             SSLfatal(s, SSL_AD_DECODE_ERROR,
1847                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1848                      SSL_R_CERT_LENGTH_MISMATCH);
1849             goto err;
1850         }
1851 
1852         certstart = certbytes;
1853         x = d2i_X509(NULL, (const unsigned char **)&certbytes, cert_len);
1854         if (x == NULL) {
1855             SSLfatal(s, SSL_AD_BAD_CERTIFICATE,
1856                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_ASN1_LIB);
1857             goto err;
1858         }
1859         if (certbytes != (certstart + cert_len)) {
1860             SSLfatal(s, SSL_AD_DECODE_ERROR,
1861                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1862                      SSL_R_CERT_LENGTH_MISMATCH);
1863             goto err;
1864         }
1865 
1866         if (SSL_IS_TLS13(s)) {
1867             RAW_EXTENSION *rawexts = NULL;
1868             PACKET extensions;
1869 
1870             if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
1871                 SSLfatal(s, SSL_AD_DECODE_ERROR,
1872                          SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1873                          SSL_R_BAD_LENGTH);
1874                 goto err;
1875             }
1876             if (!tls_collect_extensions(s, &extensions,
1877                                         SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
1878                                         NULL, chainidx == 0)
1879                 || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
1880                                              rawexts, x, chainidx,
1881                                              PACKET_remaining(pkt) == 0)) {
1882                 OPENSSL_free(rawexts);
1883                 /* SSLfatal already called */
1884                 goto err;
1885             }
1886             OPENSSL_free(rawexts);
1887         }
1888 
1889         if (!sk_X509_push(sk, x)) {
1890             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1891                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1892                      ERR_R_MALLOC_FAILURE);
1893             goto err;
1894         }
1895         x = NULL;
1896     }
1897 
1898     i = ssl_verify_cert_chain(s, sk);
1899     /*
1900      * The documented interface is that SSL_VERIFY_PEER should be set in order
1901      * for client side verification of the server certificate to take place.
1902      * However, historically the code has only checked that *any* flag is set
1903      * to cause server verification to take place. Use of the other flags makes
1904      * no sense in client mode. An attempt to clean up the semantics was
1905      * reverted because at least one application *only* set
1906      * SSL_VERIFY_FAIL_IF_NO_PEER_CERT. Prior to the clean up this still caused
1907      * server verification to take place, after the clean up it silently did
1908      * nothing. SSL_CTX_set_verify()/SSL_set_verify() cannot validate the flags
1909      * sent to them because they are void functions. Therefore, we now use the
1910      * (less clean) historic behaviour of performing validation if any flag is
1911      * set. The *documented* interface remains the same.
1912      */
1913     if (s->verify_mode != SSL_VERIFY_NONE && i <= 0) {
1914         SSLfatal(s, ssl_x509err2alert(s->verify_result),
1915                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1916                  SSL_R_CERTIFICATE_VERIFY_FAILED);
1917         goto err;
1918     }
1919     ERR_clear_error();          /* but we keep s->verify_result */
1920     if (i > 1) {
1921         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
1922                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, i);
1923         goto err;
1924     }
1925 
1926     s->session->peer_chain = sk;
1927     /*
1928      * Inconsistency alert: cert_chain does include the peer's certificate,
1929      * which we don't include in statem_srvr.c
1930      */
1931     x = sk_X509_value(sk, 0);
1932     sk = NULL;
1933 
1934     pkey = X509_get0_pubkey(x);
1935 
1936     if (pkey == NULL || EVP_PKEY_missing_parameters(pkey)) {
1937         x = NULL;
1938         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1939                  SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS);
1940         goto err;
1941     }
1942 
1943     if ((clu = ssl_cert_lookup_by_pkey(pkey, &certidx)) == NULL) {
1944         x = NULL;
1945         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1946                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1947                  SSL_R_UNKNOWN_CERTIFICATE_TYPE);
1948         goto err;
1949     }
1950     /*
1951      * Check certificate type is consistent with ciphersuite. For TLS 1.3
1952      * skip check since TLS 1.3 ciphersuites can be used with any certificate
1953      * type.
1954      */
1955     if (!SSL_IS_TLS13(s)) {
1956         if ((clu->amask & s->s3->tmp.new_cipher->algorithm_auth) == 0) {
1957             x = NULL;
1958             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1959                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1960                      SSL_R_WRONG_CERTIFICATE_TYPE);
1961             goto err;
1962         }
1963     }
1964 
1965     X509_free(s->session->peer);
1966     X509_up_ref(x);
1967     s->session->peer = x;
1968     s->session->verify_result = s->verify_result;
1969     x = NULL;
1970 
1971     /* Save the current hash state for when we receive the CertificateVerify */
1972     if (SSL_IS_TLS13(s)
1973             && !ssl_handshake_hash(s, s->cert_verify_hash,
1974                                    sizeof(s->cert_verify_hash),
1975                                    &s->cert_verify_hash_len)) {
1976         /* SSLfatal() already called */;
1977         goto err;
1978     }
1979 
1980     ret = MSG_PROCESS_CONTINUE_READING;
1981 
1982  err:
1983     X509_free(x);
1984     sk_X509_pop_free(sk, X509_free);
1985     return ret;
1986 }
1987 
1988 static int tls_process_ske_psk_preamble(SSL *s, PACKET *pkt)
1989 {
1990 #ifndef OPENSSL_NO_PSK
1991     PACKET psk_identity_hint;
1992 
1993     /* PSK ciphersuites are preceded by an identity hint */
1994 
1995     if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {
1996         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
1997                  SSL_R_LENGTH_MISMATCH);
1998         return 0;
1999     }
2000 
2001     /*
2002      * Store PSK identity hint for later use, hint is used in
2003      * tls_construct_client_key_exchange.  Assume that the maximum length of
2004      * a PSK identity hint can be as long as the maximum length of a PSK
2005      * identity.
2006      */
2007     if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {
2008         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2009                  SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2010                  SSL_R_DATA_LENGTH_TOO_LONG);
2011         return 0;
2012     }
2013 
2014     if (PACKET_remaining(&psk_identity_hint) == 0) {
2015         OPENSSL_free(s->session->psk_identity_hint);
2016         s->session->psk_identity_hint = NULL;
2017     } else if (!PACKET_strndup(&psk_identity_hint,
2018                                &s->session->psk_identity_hint)) {
2019         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2020                  ERR_R_INTERNAL_ERROR);
2021         return 0;
2022     }
2023 
2024     return 1;
2025 #else
2026     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2027              ERR_R_INTERNAL_ERROR);
2028     return 0;
2029 #endif
2030 }
2031 
2032 static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2033 {
2034 #ifndef OPENSSL_NO_SRP
2035     PACKET prime, generator, salt, server_pub;
2036 
2037     if (!PACKET_get_length_prefixed_2(pkt, &prime)
2038         || !PACKET_get_length_prefixed_2(pkt, &generator)
2039         || !PACKET_get_length_prefixed_1(pkt, &salt)
2040         || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
2041         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2042                  SSL_R_LENGTH_MISMATCH);
2043         return 0;
2044     }
2045 
2046     /* TODO(size_t): Convert BN_bin2bn() calls */
2047     if ((s->srp_ctx.N =
2048          BN_bin2bn(PACKET_data(&prime),
2049                    (int)PACKET_remaining(&prime), NULL)) == NULL
2050         || (s->srp_ctx.g =
2051             BN_bin2bn(PACKET_data(&generator),
2052                       (int)PACKET_remaining(&generator), NULL)) == NULL
2053         || (s->srp_ctx.s =
2054             BN_bin2bn(PACKET_data(&salt),
2055                       (int)PACKET_remaining(&salt), NULL)) == NULL
2056         || (s->srp_ctx.B =
2057             BN_bin2bn(PACKET_data(&server_pub),
2058                       (int)PACKET_remaining(&server_pub), NULL)) == NULL) {
2059         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2060                  ERR_R_BN_LIB);
2061         return 0;
2062     }
2063 
2064     if (!srp_verify_server_param(s)) {
2065         /* SSLfatal() already called */
2066         return 0;
2067     }
2068 
2069     /* We must check if there is a certificate */
2070     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
2071         *pkey = X509_get0_pubkey(s->session->peer);
2072 
2073     return 1;
2074 #else
2075     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2076              ERR_R_INTERNAL_ERROR);
2077     return 0;
2078 #endif
2079 }
2080 
2081 static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2082 {
2083 #ifndef OPENSSL_NO_DH
2084     PACKET prime, generator, pub_key;
2085     EVP_PKEY *peer_tmp = NULL;
2086 
2087     DH *dh = NULL;
2088     BIGNUM *p = NULL, *g = NULL, *bnpub_key = NULL;
2089 
2090     int check_bits = 0;
2091 
2092     if (!PACKET_get_length_prefixed_2(pkt, &prime)
2093         || !PACKET_get_length_prefixed_2(pkt, &generator)
2094         || !PACKET_get_length_prefixed_2(pkt, &pub_key)) {
2095         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2096                  SSL_R_LENGTH_MISMATCH);
2097         return 0;
2098     }
2099 
2100     peer_tmp = EVP_PKEY_new();
2101     dh = DH_new();
2102 
2103     if (peer_tmp == NULL || dh == NULL) {
2104         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2105                  ERR_R_MALLOC_FAILURE);
2106         goto err;
2107     }
2108 
2109     /* TODO(size_t): Convert these calls */
2110     p = BN_bin2bn(PACKET_data(&prime), (int)PACKET_remaining(&prime), NULL);
2111     g = BN_bin2bn(PACKET_data(&generator), (int)PACKET_remaining(&generator),
2112                   NULL);
2113     bnpub_key = BN_bin2bn(PACKET_data(&pub_key),
2114                           (int)PACKET_remaining(&pub_key), NULL);
2115     if (p == NULL || g == NULL || bnpub_key == NULL) {
2116         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2117                  ERR_R_BN_LIB);
2118         goto err;
2119     }
2120 
2121     /* test non-zero pubkey */
2122     if (BN_is_zero(bnpub_key)) {
2123         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
2124                  SSL_R_BAD_DH_VALUE);
2125         goto err;
2126     }
2127 
2128     if (!DH_set0_pqg(dh, p, NULL, g)) {
2129         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2130                  ERR_R_BN_LIB);
2131         goto err;
2132     }
2133     p = g = NULL;
2134 
2135     if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
2136         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
2137                  SSL_R_BAD_DH_VALUE);
2138         goto err;
2139     }
2140 
2141     if (!DH_set0_key(dh, bnpub_key, NULL)) {
2142         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2143                  ERR_R_BN_LIB);
2144         goto err;
2145     }
2146     bnpub_key = NULL;
2147 
2148     if (EVP_PKEY_assign_DH(peer_tmp, dh) == 0) {
2149         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2150                  ERR_R_EVP_LIB);
2151         goto err;
2152     }
2153     dh = NULL;
2154 
2155     if (!ssl_security(s, SSL_SECOP_TMP_DH, EVP_PKEY_security_bits(peer_tmp),
2156                       0, peer_tmp)) {
2157         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SKE_DHE,
2158                  SSL_R_DH_KEY_TOO_SMALL);
2159         goto err;
2160     }
2161 
2162     s->s3->peer_tmp = peer_tmp;
2163 
2164     /*
2165      * FIXME: This makes assumptions about which ciphersuites come with
2166      * public keys. We should have a less ad-hoc way of doing this
2167      */
2168     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
2169         *pkey = X509_get0_pubkey(s->session->peer);
2170     /* else anonymous DH, so no certificate or pkey. */
2171 
2172     return 1;
2173 
2174  err:
2175     BN_free(p);
2176     BN_free(g);
2177     BN_free(bnpub_key);
2178     DH_free(dh);
2179     EVP_PKEY_free(peer_tmp);
2180 
2181     return 0;
2182 #else
2183     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2184              ERR_R_INTERNAL_ERROR);
2185     return 0;
2186 #endif
2187 }
2188 
2189 static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2190 {
2191 #ifndef OPENSSL_NO_EC
2192     PACKET encoded_pt;
2193     unsigned int curve_type, curve_id;
2194 
2195     /*
2196      * Extract elliptic curve parameters and the server's ephemeral ECDH
2197      * public key. We only support named (not generic) curves and
2198      * ECParameters in this case is just three bytes.
2199      */
2200     if (!PACKET_get_1(pkt, &curve_type) || !PACKET_get_net_2(pkt, &curve_id)) {
2201         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2202                  SSL_R_LENGTH_TOO_SHORT);
2203         return 0;
2204     }
2205     /*
2206      * Check curve is named curve type and one of our preferences, if not
2207      * server has sent an invalid curve.
2208      */
2209     if (curve_type != NAMED_CURVE_TYPE
2210             || !tls1_check_group_id(s, curve_id, 1)) {
2211         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
2212                  SSL_R_WRONG_CURVE);
2213         return 0;
2214     }
2215 
2216     if ((s->s3->peer_tmp = ssl_generate_param_group(curve_id)) == NULL) {
2217         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2218                  SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
2219         return 0;
2220     }
2221 
2222     if (!PACKET_get_length_prefixed_1(pkt, &encoded_pt)) {
2223         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2224                  SSL_R_LENGTH_MISMATCH);
2225         return 0;
2226     }
2227 
2228     if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
2229                                         PACKET_data(&encoded_pt),
2230                                         PACKET_remaining(&encoded_pt))) {
2231         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
2232                  SSL_R_BAD_ECPOINT);
2233         return 0;
2234     }
2235 
2236     /*
2237      * The ECC/TLS specification does not mention the use of DSA to sign
2238      * ECParameters in the server key exchange message. We do support RSA
2239      * and ECDSA.
2240      */
2241     if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aECDSA)
2242         *pkey = X509_get0_pubkey(s->session->peer);
2243     else if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aRSA)
2244         *pkey = X509_get0_pubkey(s->session->peer);
2245     /* else anonymous ECDH, so no certificate or pkey. */
2246 
2247     return 1;
2248 #else
2249     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2250              ERR_R_INTERNAL_ERROR);
2251     return 0;
2252 #endif
2253 }
2254 
2255 MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
2256 {
2257     long alg_k;
2258     EVP_PKEY *pkey = NULL;
2259     EVP_MD_CTX *md_ctx = NULL;
2260     EVP_PKEY_CTX *pctx = NULL;
2261     PACKET save_param_start, signature;
2262 
2263     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
2264 
2265     save_param_start = *pkt;
2266 
2267 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
2268     EVP_PKEY_free(s->s3->peer_tmp);
2269     s->s3->peer_tmp = NULL;
2270 #endif
2271 
2272     if (alg_k & SSL_PSK) {
2273         if (!tls_process_ske_psk_preamble(s, pkt)) {
2274             /* SSLfatal() already called */
2275             goto err;
2276         }
2277     }
2278 
2279     /* Nothing else to do for plain PSK or RSAPSK */
2280     if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
2281     } else if (alg_k & SSL_kSRP) {
2282         if (!tls_process_ske_srp(s, pkt, &pkey)) {
2283             /* SSLfatal() already called */
2284             goto err;
2285         }
2286     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
2287         if (!tls_process_ske_dhe(s, pkt, &pkey)) {
2288             /* SSLfatal() already called */
2289             goto err;
2290         }
2291     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
2292         if (!tls_process_ske_ecdhe(s, pkt, &pkey)) {
2293             /* SSLfatal() already called */
2294             goto err;
2295         }
2296     } else if (alg_k) {
2297         SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2298                  SSL_R_UNEXPECTED_MESSAGE);
2299         goto err;
2300     }
2301 
2302     /* if it was signed, check the signature */
2303     if (pkey != NULL) {
2304         PACKET params;
2305         int maxsig;
2306         const EVP_MD *md = NULL;
2307         unsigned char *tbs;
2308         size_t tbslen;
2309         int rv;
2310 
2311         /*
2312          * |pkt| now points to the beginning of the signature, so the difference
2313          * equals the length of the parameters.
2314          */
2315         if (!PACKET_get_sub_packet(&save_param_start, &params,
2316                                    PACKET_remaining(&save_param_start) -
2317                                    PACKET_remaining(pkt))) {
2318             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2319                      ERR_R_INTERNAL_ERROR);
2320             goto err;
2321         }
2322 
2323         if (SSL_USE_SIGALGS(s)) {
2324             unsigned int sigalg;
2325 
2326             if (!PACKET_get_net_2(pkt, &sigalg)) {
2327                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2328                          SSL_R_LENGTH_TOO_SHORT);
2329                 goto err;
2330             }
2331             if (tls12_check_peer_sigalg(s, sigalg, pkey) <=0) {
2332                 /* SSLfatal() already called */
2333                 goto err;
2334             }
2335         } else if (!tls1_set_peer_legacy_sigalg(s, pkey)) {
2336             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2337                      ERR_R_INTERNAL_ERROR);
2338             goto err;
2339         }
2340 
2341         if (!tls1_lookup_md(s->s3->tmp.peer_sigalg, &md)) {
2342             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2343                      ERR_R_INTERNAL_ERROR);
2344             goto err;
2345         }
2346 #ifdef SSL_DEBUG
2347         if (SSL_USE_SIGALGS(s))
2348             fprintf(stderr, "USING TLSv1.2 HASH %s\n",
2349                     md == NULL ? "n/a" : EVP_MD_name(md));
2350 #endif
2351 
2352         if (!PACKET_get_length_prefixed_2(pkt, &signature)
2353             || PACKET_remaining(pkt) != 0) {
2354             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2355                      SSL_R_LENGTH_MISMATCH);
2356             goto err;
2357         }
2358         maxsig = EVP_PKEY_size(pkey);
2359         if (maxsig < 0) {
2360             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2361                      ERR_R_INTERNAL_ERROR);
2362             goto err;
2363         }
2364 
2365         /*
2366          * Check signature length
2367          */
2368         if (PACKET_remaining(&signature) > (size_t)maxsig) {
2369             /* wrong packet length */
2370             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2371                    SSL_R_WRONG_SIGNATURE_LENGTH);
2372             goto err;
2373         }
2374 
2375         md_ctx = EVP_MD_CTX_new();
2376         if (md_ctx == NULL) {
2377             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2378                      ERR_R_MALLOC_FAILURE);
2379             goto err;
2380         }
2381 
2382         if (EVP_DigestVerifyInit(md_ctx, &pctx, md, NULL, pkey) <= 0) {
2383             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2384                      ERR_R_EVP_LIB);
2385             goto err;
2386         }
2387         if (SSL_USE_PSS(s)) {
2388             if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
2389                 || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx,
2390                                                 RSA_PSS_SALTLEN_DIGEST) <= 0) {
2391                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2392                          SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
2393                 goto err;
2394             }
2395         }
2396         tbslen = construct_key_exchange_tbs(s, &tbs, PACKET_data(&params),
2397                                             PACKET_remaining(&params));
2398         if (tbslen == 0) {
2399             /* SSLfatal() already called */
2400             goto err;
2401         }
2402 
2403         rv = EVP_DigestVerify(md_ctx, PACKET_data(&signature),
2404                               PACKET_remaining(&signature), tbs, tbslen);
2405         OPENSSL_free(tbs);
2406         if (rv <= 0) {
2407             SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2408                      SSL_R_BAD_SIGNATURE);
2409             goto err;
2410         }
2411         EVP_MD_CTX_free(md_ctx);
2412         md_ctx = NULL;
2413     } else {
2414         /* aNULL, aSRP or PSK do not need public keys */
2415         if (!(s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aSRP))
2416             && !(alg_k & SSL_PSK)) {
2417             /* Might be wrong key type, check it */
2418             if (ssl3_check_cert_and_algorithm(s)) {
2419                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2420                          SSL_R_BAD_DATA);
2421             }
2422             /* else this shouldn't happen, SSLfatal() already called */
2423             goto err;
2424         }
2425         /* still data left over */
2426         if (PACKET_remaining(pkt) != 0) {
2427             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2428                      SSL_R_EXTRA_DATA_IN_MESSAGE);
2429             goto err;
2430         }
2431     }
2432 
2433     return MSG_PROCESS_CONTINUE_READING;
2434  err:
2435     EVP_MD_CTX_free(md_ctx);
2436     return MSG_PROCESS_ERROR;
2437 }
2438 
2439 MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
2440 {
2441     size_t i;
2442 
2443     /* Clear certificate validity flags */
2444     for (i = 0; i < SSL_PKEY_NUM; i++)
2445         s->s3->tmp.valid_flags[i] = 0;
2446 
2447     if (SSL_IS_TLS13(s)) {
2448         PACKET reqctx, extensions;
2449         RAW_EXTENSION *rawexts = NULL;
2450 
2451         if ((s->shutdown & SSL_SENT_SHUTDOWN) != 0) {
2452             /*
2453              * We already sent close_notify. This can only happen in TLSv1.3
2454              * post-handshake messages. We can't reasonably respond to this, so
2455              * we just ignore it
2456              */
2457             return MSG_PROCESS_FINISHED_READING;
2458         }
2459 
2460         /* Free and zero certificate types: it is not present in TLS 1.3 */
2461         OPENSSL_free(s->s3->tmp.ctype);
2462         s->s3->tmp.ctype = NULL;
2463         s->s3->tmp.ctype_len = 0;
2464         OPENSSL_free(s->pha_context);
2465         s->pha_context = NULL;
2466         s->pha_context_len = 0;
2467 
2468         if (!PACKET_get_length_prefixed_1(pkt, &reqctx) ||
2469             !PACKET_memdup(&reqctx, &s->pha_context, &s->pha_context_len)) {
2470             SSLfatal(s, SSL_AD_DECODE_ERROR,
2471                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2472                      SSL_R_LENGTH_MISMATCH);
2473             return MSG_PROCESS_ERROR;
2474         }
2475 
2476         if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
2477             SSLfatal(s, SSL_AD_DECODE_ERROR,
2478                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2479                      SSL_R_BAD_LENGTH);
2480             return MSG_PROCESS_ERROR;
2481         }
2482         if (!tls_collect_extensions(s, &extensions,
2483                                     SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
2484                                     &rawexts, NULL, 1)
2485             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
2486                                          rawexts, NULL, 0, 1)) {
2487             /* SSLfatal() already called */
2488             OPENSSL_free(rawexts);
2489             return MSG_PROCESS_ERROR;
2490         }
2491         OPENSSL_free(rawexts);
2492         if (!tls1_process_sigalgs(s)) {
2493             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2494                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2495                      SSL_R_BAD_LENGTH);
2496             return MSG_PROCESS_ERROR;
2497         }
2498     } else {
2499         PACKET ctypes;
2500 
2501         /* get the certificate types */
2502         if (!PACKET_get_length_prefixed_1(pkt, &ctypes)) {
2503             SSLfatal(s, SSL_AD_DECODE_ERROR,
2504                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2505                      SSL_R_LENGTH_MISMATCH);
2506             return MSG_PROCESS_ERROR;
2507         }
2508 
2509         if (!PACKET_memdup(&ctypes, &s->s3->tmp.ctype, &s->s3->tmp.ctype_len)) {
2510             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2511                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2512                      ERR_R_INTERNAL_ERROR);
2513             return MSG_PROCESS_ERROR;
2514         }
2515 
2516         if (SSL_USE_SIGALGS(s)) {
2517             PACKET sigalgs;
2518 
2519             if (!PACKET_get_length_prefixed_2(pkt, &sigalgs)) {
2520                 SSLfatal(s, SSL_AD_DECODE_ERROR,
2521                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2522                          SSL_R_LENGTH_MISMATCH);
2523                 return MSG_PROCESS_ERROR;
2524             }
2525 
2526             /*
2527              * Despite this being for certificates, preserve compatibility
2528              * with pre-TLS 1.3 and use the regular sigalgs field.
2529              */
2530             if (!tls1_save_sigalgs(s, &sigalgs, 0)) {
2531                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2532                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2533                          SSL_R_SIGNATURE_ALGORITHMS_ERROR);
2534                 return MSG_PROCESS_ERROR;
2535             }
2536             if (!tls1_process_sigalgs(s)) {
2537                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2538                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2539                          ERR_R_MALLOC_FAILURE);
2540                 return MSG_PROCESS_ERROR;
2541             }
2542         }
2543 
2544         /* get the CA RDNs */
2545         if (!parse_ca_names(s, pkt)) {
2546             /* SSLfatal() already called */
2547             return MSG_PROCESS_ERROR;
2548         }
2549     }
2550 
2551     if (PACKET_remaining(pkt) != 0) {
2552         SSLfatal(s, SSL_AD_DECODE_ERROR,
2553                  SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2554                  SSL_R_LENGTH_MISMATCH);
2555         return MSG_PROCESS_ERROR;
2556     }
2557 
2558     /* we should setup a certificate to return.... */
2559     s->s3->tmp.cert_req = 1;
2560 
2561     /*
2562      * In TLSv1.3 we don't prepare the client certificate yet. We wait until
2563      * after the CertificateVerify message has been received. This is because
2564      * in TLSv1.3 the CertificateRequest arrives before the Certificate message
2565      * but in TLSv1.2 it is the other way around. We want to make sure that
2566      * SSL_get_peer_certificate() returns something sensible in
2567      * client_cert_cb.
2568      */
2569     if (SSL_IS_TLS13(s) && s->post_handshake_auth != SSL_PHA_REQUESTED)
2570         return MSG_PROCESS_CONTINUE_READING;
2571 
2572     return MSG_PROCESS_CONTINUE_PROCESSING;
2573 }
2574 
2575 MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
2576 {
2577     unsigned int ticklen;
2578     unsigned long ticket_lifetime_hint, age_add = 0;
2579     unsigned int sess_len;
2580     RAW_EXTENSION *exts = NULL;
2581     PACKET nonce;
2582 
2583     PACKET_null_init(&nonce);
2584 
2585     if (!PACKET_get_net_4(pkt, &ticket_lifetime_hint)
2586         || (SSL_IS_TLS13(s)
2587             && (!PACKET_get_net_4(pkt, &age_add)
2588                 || !PACKET_get_length_prefixed_1(pkt, &nonce)))
2589         || !PACKET_get_net_2(pkt, &ticklen)
2590         || (SSL_IS_TLS13(s) ? (ticklen == 0 || PACKET_remaining(pkt) < ticklen)
2591                             : PACKET_remaining(pkt) != ticklen)) {
2592         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2593                  SSL_R_LENGTH_MISMATCH);
2594         goto err;
2595     }
2596 
2597     /*
2598      * Server is allowed to change its mind (in <=TLSv1.2) and send an empty
2599      * ticket. We already checked this TLSv1.3 case above, so it should never
2600      * be 0 here in that instance
2601      */
2602     if (ticklen == 0)
2603         return MSG_PROCESS_CONTINUE_READING;
2604 
2605     /*
2606      * Sessions must be immutable once they go into the session cache. Otherwise
2607      * we can get multi-thread problems. Therefore we don't "update" sessions,
2608      * we replace them with a duplicate. In TLSv1.3 we need to do this every
2609      * time a NewSessionTicket arrives because those messages arrive
2610      * post-handshake and the session may have already gone into the session
2611      * cache.
2612      */
2613     if (SSL_IS_TLS13(s) || s->session->session_id_length > 0) {
2614         SSL_SESSION *new_sess;
2615 
2616         /*
2617          * We reused an existing session, so we need to replace it with a new
2618          * one
2619          */
2620         if ((new_sess = ssl_session_dup(s->session, 0)) == 0) {
2621             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2622                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2623                      ERR_R_MALLOC_FAILURE);
2624             goto err;
2625         }
2626 
2627         if ((s->session_ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) != 0
2628                 && !SSL_IS_TLS13(s)) {
2629             /*
2630              * In TLSv1.2 and below the arrival of a new tickets signals that
2631              * any old ticket we were using is now out of date, so we remove the
2632              * old session from the cache. We carry on if this fails
2633              */
2634             SSL_CTX_remove_session(s->session_ctx, s->session);
2635         }
2636 
2637         SSL_SESSION_free(s->session);
2638         s->session = new_sess;
2639     }
2640 
2641     /*
2642      * Technically the cast to long here is not guaranteed by the C standard -
2643      * but we use it elsewhere, so this should be ok.
2644      */
2645     s->session->time = (long)time(NULL);
2646 
2647     OPENSSL_free(s->session->ext.tick);
2648     s->session->ext.tick = NULL;
2649     s->session->ext.ticklen = 0;
2650 
2651     s->session->ext.tick = OPENSSL_malloc(ticklen);
2652     if (s->session->ext.tick == NULL) {
2653         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2654                  ERR_R_MALLOC_FAILURE);
2655         goto err;
2656     }
2657     if (!PACKET_copy_bytes(pkt, s->session->ext.tick, ticklen)) {
2658         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2659                  SSL_R_LENGTH_MISMATCH);
2660         goto err;
2661     }
2662 
2663     s->session->ext.tick_lifetime_hint = ticket_lifetime_hint;
2664     s->session->ext.tick_age_add = age_add;
2665     s->session->ext.ticklen = ticklen;
2666 
2667     if (SSL_IS_TLS13(s)) {
2668         PACKET extpkt;
2669 
2670         if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
2671                 || PACKET_remaining(pkt) != 0) {
2672             SSLfatal(s, SSL_AD_DECODE_ERROR,
2673                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2674                      SSL_R_LENGTH_MISMATCH);
2675             goto err;
2676         }
2677 
2678         if (!tls_collect_extensions(s, &extpkt,
2679                                     SSL_EXT_TLS1_3_NEW_SESSION_TICKET, &exts,
2680                                     NULL, 1)
2681                 || !tls_parse_all_extensions(s,
2682                                              SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
2683                                              exts, NULL, 0, 1)) {
2684             /* SSLfatal() already called */
2685             goto err;
2686         }
2687     }
2688 
2689     /*
2690      * There are two ways to detect a resumed ticket session. One is to set
2691      * an appropriate session ID and then the server must return a match in
2692      * ServerHello. This allows the normal client session ID matching to work
2693      * and we know much earlier that the ticket has been accepted. The
2694      * other way is to set zero length session ID when the ticket is
2695      * presented and rely on the handshake to determine session resumption.
2696      * We choose the former approach because this fits in with assumptions
2697      * elsewhere in OpenSSL. The session ID is set to the SHA256 (or SHA1 is
2698      * SHA256 is disabled) hash of the ticket.
2699      */
2700     /*
2701      * TODO(size_t): we use sess_len here because EVP_Digest expects an int
2702      * but s->session->session_id_length is a size_t
2703      */
2704     if (!EVP_Digest(s->session->ext.tick, ticklen,
2705                     s->session->session_id, &sess_len,
2706                     EVP_sha256(), NULL)) {
2707         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2708                  ERR_R_EVP_LIB);
2709         goto err;
2710     }
2711     s->session->session_id_length = sess_len;
2712     s->session->not_resumable = 0;
2713 
2714     /* This is a standalone message in TLSv1.3, so there is no more to read */
2715     if (SSL_IS_TLS13(s)) {
2716         const EVP_MD *md = ssl_handshake_md(s);
2717         int hashleni = EVP_MD_size(md);
2718         size_t hashlen;
2719         static const unsigned char nonce_label[] = "resumption";
2720 
2721         /* Ensure cast to size_t is safe */
2722         if (!ossl_assert(hashleni >= 0)) {
2723             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2724                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2725                      ERR_R_INTERNAL_ERROR);
2726             goto err;
2727         }
2728         hashlen = (size_t)hashleni;
2729 
2730         if (!tls13_hkdf_expand(s, md, s->resumption_master_secret,
2731                                nonce_label,
2732                                sizeof(nonce_label) - 1,
2733                                PACKET_data(&nonce),
2734                                PACKET_remaining(&nonce),
2735                                s->session->master_key,
2736                                hashlen, 1)) {
2737             /* SSLfatal() already called */
2738             goto err;
2739         }
2740         s->session->master_key_length = hashlen;
2741 
2742         OPENSSL_free(exts);
2743         ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
2744         return MSG_PROCESS_FINISHED_READING;
2745     }
2746 
2747     return MSG_PROCESS_CONTINUE_READING;
2748  err:
2749     OPENSSL_free(exts);
2750     return MSG_PROCESS_ERROR;
2751 }
2752 
2753 /*
2754  * In TLSv1.3 this is called from the extensions code, otherwise it is used to
2755  * parse a separate message. Returns 1 on success or 0 on failure
2756  */
2757 int tls_process_cert_status_body(SSL *s, PACKET *pkt)
2758 {
2759     size_t resplen;
2760     unsigned int type;
2761 
2762     if (!PACKET_get_1(pkt, &type)
2763         || type != TLSEXT_STATUSTYPE_ocsp) {
2764         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2765                  SSL_R_UNSUPPORTED_STATUS_TYPE);
2766         return 0;
2767     }
2768     if (!PACKET_get_net_3_len(pkt, &resplen)
2769         || PACKET_remaining(pkt) != resplen) {
2770         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2771                  SSL_R_LENGTH_MISMATCH);
2772         return 0;
2773     }
2774     s->ext.ocsp.resp = OPENSSL_malloc(resplen);
2775     if (s->ext.ocsp.resp == NULL) {
2776         s->ext.ocsp.resp_len = 0;
2777         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2778                  ERR_R_MALLOC_FAILURE);
2779         return 0;
2780     }
2781     s->ext.ocsp.resp_len = resplen;
2782     if (!PACKET_copy_bytes(pkt, s->ext.ocsp.resp, resplen)) {
2783         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2784                  SSL_R_LENGTH_MISMATCH);
2785         return 0;
2786     }
2787 
2788     return 1;
2789 }
2790 
2791 
2792 MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt)
2793 {
2794     if (!tls_process_cert_status_body(s, pkt)) {
2795         /* SSLfatal() already called */
2796         return MSG_PROCESS_ERROR;
2797     }
2798 
2799     return MSG_PROCESS_CONTINUE_READING;
2800 }
2801 
2802 /*
2803  * Perform miscellaneous checks and processing after we have received the
2804  * server's initial flight. In TLS1.3 this is after the Server Finished message.
2805  * In <=TLS1.2 this is after the ServerDone message. Returns 1 on success or 0
2806  * on failure.
2807  */
2808 int tls_process_initial_server_flight(SSL *s)
2809 {
2810     /*
2811      * at this point we check that we have the required stuff from
2812      * the server
2813      */
2814     if (!ssl3_check_cert_and_algorithm(s)) {
2815         /* SSLfatal() already called */
2816         return 0;
2817     }
2818 
2819     /*
2820      * Call the ocsp status callback if needed. The |ext.ocsp.resp| and
2821      * |ext.ocsp.resp_len| values will be set if we actually received a status
2822      * message, or NULL and -1 otherwise
2823      */
2824     if (s->ext.status_type != TLSEXT_STATUSTYPE_nothing
2825             && s->ctx->ext.status_cb != NULL) {
2826         int ret = s->ctx->ext.status_cb(s, s->ctx->ext.status_arg);
2827 
2828         if (ret == 0) {
2829             SSLfatal(s, SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE,
2830                      SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
2831                      SSL_R_INVALID_STATUS_RESPONSE);
2832             return 0;
2833         }
2834         if (ret < 0) {
2835             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2836                      SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
2837                      SSL_R_OCSP_CALLBACK_FAILURE);
2838             return 0;
2839         }
2840     }
2841 #ifndef OPENSSL_NO_CT
2842     if (s->ct_validation_callback != NULL) {
2843         /* Note we validate the SCTs whether or not we abort on error */
2844         if (!ssl_validate_ct(s) && (s->verify_mode & SSL_VERIFY_PEER)) {
2845             /* SSLfatal() already called */
2846             return 0;
2847         }
2848     }
2849 #endif
2850 
2851     return 1;
2852 }
2853 
2854 MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt)
2855 {
2856     if (PACKET_remaining(pkt) > 0) {
2857         /* should contain no data */
2858         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
2859                  SSL_R_LENGTH_MISMATCH);
2860         return MSG_PROCESS_ERROR;
2861     }
2862 #ifndef OPENSSL_NO_SRP
2863     if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
2864         if (SRP_Calc_A_param(s) <= 0) {
2865             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
2866                      SSL_R_SRP_A_CALC);
2867             return MSG_PROCESS_ERROR;
2868         }
2869     }
2870 #endif
2871 
2872     if (!tls_process_initial_server_flight(s)) {
2873         /* SSLfatal() already called */
2874         return MSG_PROCESS_ERROR;
2875     }
2876 
2877     return MSG_PROCESS_FINISHED_READING;
2878 }
2879 
2880 static int tls_construct_cke_psk_preamble(SSL *s, WPACKET *pkt)
2881 {
2882 #ifndef OPENSSL_NO_PSK
2883     int ret = 0;
2884     /*
2885      * The callback needs PSK_MAX_IDENTITY_LEN + 1 bytes to return a
2886      * \0-terminated identity. The last byte is for us for simulating
2887      * strnlen.
2888      */
2889     char identity[PSK_MAX_IDENTITY_LEN + 1];
2890     size_t identitylen = 0;
2891     unsigned char psk[PSK_MAX_PSK_LEN];
2892     unsigned char *tmppsk = NULL;
2893     char *tmpidentity = NULL;
2894     size_t psklen = 0;
2895 
2896     if (s->psk_client_callback == NULL) {
2897         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2898                  SSL_R_PSK_NO_CLIENT_CB);
2899         goto err;
2900     }
2901 
2902     memset(identity, 0, sizeof(identity));
2903 
2904     psklen = s->psk_client_callback(s, s->session->psk_identity_hint,
2905                                     identity, sizeof(identity) - 1,
2906                                     psk, sizeof(psk));
2907 
2908     if (psklen > PSK_MAX_PSK_LEN) {
2909         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2910                  SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
2911         psklen = PSK_MAX_PSK_LEN;   /* Avoid overrunning the array on cleanse */
2912         goto err;
2913     } else if (psklen == 0) {
2914         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2915                  SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2916                  SSL_R_PSK_IDENTITY_NOT_FOUND);
2917         goto err;
2918     }
2919 
2920     identitylen = strlen(identity);
2921     if (identitylen > PSK_MAX_IDENTITY_LEN) {
2922         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2923                  ERR_R_INTERNAL_ERROR);
2924         goto err;
2925     }
2926 
2927     tmppsk = OPENSSL_memdup(psk, psklen);
2928     tmpidentity = OPENSSL_strdup(identity);
2929     if (tmppsk == NULL || tmpidentity == NULL) {
2930         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2931                  ERR_R_MALLOC_FAILURE);
2932         goto err;
2933     }
2934 
2935     OPENSSL_free(s->s3->tmp.psk);
2936     s->s3->tmp.psk = tmppsk;
2937     s->s3->tmp.psklen = psklen;
2938     tmppsk = NULL;
2939     OPENSSL_free(s->session->psk_identity);
2940     s->session->psk_identity = tmpidentity;
2941     tmpidentity = NULL;
2942 
2943     if (!WPACKET_sub_memcpy_u16(pkt, identity, identitylen))  {
2944         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2945                  ERR_R_INTERNAL_ERROR);
2946         goto err;
2947     }
2948 
2949     ret = 1;
2950 
2951  err:
2952     OPENSSL_cleanse(psk, psklen);
2953     OPENSSL_cleanse(identity, sizeof(identity));
2954     OPENSSL_clear_free(tmppsk, psklen);
2955     OPENSSL_clear_free(tmpidentity, identitylen);
2956 
2957     return ret;
2958 #else
2959     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2960              ERR_R_INTERNAL_ERROR);
2961     return 0;
2962 #endif
2963 }
2964 
2965 static int tls_construct_cke_rsa(SSL *s, WPACKET *pkt)
2966 {
2967 #ifndef OPENSSL_NO_RSA
2968     unsigned char *encdata = NULL;
2969     EVP_PKEY *pkey = NULL;
2970     EVP_PKEY_CTX *pctx = NULL;
2971     size_t enclen;
2972     unsigned char *pms = NULL;
2973     size_t pmslen = 0;
2974 
2975     if (s->session->peer == NULL) {
2976         /*
2977          * We should always have a server certificate with SSL_kRSA.
2978          */
2979         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2980                  ERR_R_INTERNAL_ERROR);
2981         return 0;
2982     }
2983 
2984     pkey = X509_get0_pubkey(s->session->peer);
2985     if (EVP_PKEY_get0_RSA(pkey) == NULL) {
2986         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2987                  ERR_R_INTERNAL_ERROR);
2988         return 0;
2989     }
2990 
2991     pmslen = SSL_MAX_MASTER_KEY_LENGTH;
2992     pms = OPENSSL_malloc(pmslen);
2993     if (pms == NULL) {
2994         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2995                  ERR_R_MALLOC_FAILURE);
2996         return 0;
2997     }
2998 
2999     pms[0] = s->client_version >> 8;
3000     pms[1] = s->client_version & 0xff;
3001     /* TODO(size_t): Convert this function */
3002     if (RAND_bytes(pms + 2, (int)(pmslen - 2)) <= 0) {
3003         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3004                  ERR_R_MALLOC_FAILURE);
3005         goto err;
3006     }
3007 
3008     /* Fix buf for TLS and beyond */
3009     if (s->version > SSL3_VERSION && !WPACKET_start_sub_packet_u16(pkt)) {
3010         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3011                  ERR_R_INTERNAL_ERROR);
3012         goto err;
3013     }
3014     pctx = EVP_PKEY_CTX_new(pkey, NULL);
3015     if (pctx == NULL || EVP_PKEY_encrypt_init(pctx) <= 0
3016         || EVP_PKEY_encrypt(pctx, NULL, &enclen, pms, pmslen) <= 0) {
3017         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3018                  ERR_R_EVP_LIB);
3019         goto err;
3020     }
3021     if (!WPACKET_allocate_bytes(pkt, enclen, &encdata)
3022             || EVP_PKEY_encrypt(pctx, encdata, &enclen, pms, pmslen) <= 0) {
3023         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3024                  SSL_R_BAD_RSA_ENCRYPT);
3025         goto err;
3026     }
3027     EVP_PKEY_CTX_free(pctx);
3028     pctx = NULL;
3029 
3030     /* Fix buf for TLS and beyond */
3031     if (s->version > SSL3_VERSION && !WPACKET_close(pkt)) {
3032         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3033                  ERR_R_INTERNAL_ERROR);
3034         goto err;
3035     }
3036 
3037     /* Log the premaster secret, if logging is enabled. */
3038     if (!ssl_log_rsa_client_key_exchange(s, encdata, enclen, pms, pmslen)) {
3039         /* SSLfatal() already called */
3040         goto err;
3041     }
3042 
3043     s->s3->tmp.pms = pms;
3044     s->s3->tmp.pmslen = pmslen;
3045 
3046     return 1;
3047  err:
3048     OPENSSL_clear_free(pms, pmslen);
3049     EVP_PKEY_CTX_free(pctx);
3050 
3051     return 0;
3052 #else
3053     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3054              ERR_R_INTERNAL_ERROR);
3055     return 0;
3056 #endif
3057 }
3058 
3059 static int tls_construct_cke_dhe(SSL *s, WPACKET *pkt)
3060 {
3061 #ifndef OPENSSL_NO_DH
3062     DH *dh_clnt = NULL;
3063     const BIGNUM *pub_key;
3064     EVP_PKEY *ckey = NULL, *skey = NULL;
3065     unsigned char *keybytes = NULL;
3066 
3067     skey = s->s3->peer_tmp;
3068     if (skey == NULL) {
3069         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3070                  ERR_R_INTERNAL_ERROR);
3071         goto err;
3072     }
3073 
3074     ckey = ssl_generate_pkey(skey);
3075     if (ckey == NULL) {
3076         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3077                  ERR_R_INTERNAL_ERROR);
3078         goto err;
3079     }
3080 
3081     dh_clnt = EVP_PKEY_get0_DH(ckey);
3082 
3083     if (dh_clnt == NULL) {
3084         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3085                  ERR_R_INTERNAL_ERROR);
3086         goto err;
3087     }
3088 
3089     if (ssl_derive(s, ckey, skey, 0) == 0) {
3090         /* SSLfatal() already called */
3091         goto err;
3092     }
3093 
3094     /* send off the data */
3095     DH_get0_key(dh_clnt, &pub_key, NULL);
3096     if (!WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(pub_key),
3097                                         &keybytes)) {
3098         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3099                  ERR_R_INTERNAL_ERROR);
3100         goto err;
3101     }
3102 
3103     BN_bn2bin(pub_key, keybytes);
3104     EVP_PKEY_free(ckey);
3105 
3106     return 1;
3107  err:
3108     EVP_PKEY_free(ckey);
3109     return 0;
3110 #else
3111     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3112              ERR_R_INTERNAL_ERROR);
3113     return 0;
3114 #endif
3115 }
3116 
3117 static int tls_construct_cke_ecdhe(SSL *s, WPACKET *pkt)
3118 {
3119 #ifndef OPENSSL_NO_EC
3120     unsigned char *encodedPoint = NULL;
3121     size_t encoded_pt_len = 0;
3122     EVP_PKEY *ckey = NULL, *skey = NULL;
3123     int ret = 0;
3124 
3125     skey = s->s3->peer_tmp;
3126     if (skey == NULL) {
3127         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3128                  ERR_R_INTERNAL_ERROR);
3129         return 0;
3130     }
3131 
3132     ckey = ssl_generate_pkey(skey);
3133     if (ckey == NULL) {
3134         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3135                  ERR_R_MALLOC_FAILURE);
3136         goto err;
3137     }
3138 
3139     if (ssl_derive(s, ckey, skey, 0) == 0) {
3140         /* SSLfatal() already called */
3141         goto err;
3142     }
3143 
3144     /* Generate encoding of client key */
3145     encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(ckey, &encodedPoint);
3146 
3147     if (encoded_pt_len == 0) {
3148         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3149                  ERR_R_EC_LIB);
3150         goto err;
3151     }
3152 
3153     if (!WPACKET_sub_memcpy_u8(pkt, encodedPoint, encoded_pt_len)) {
3154         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3155                  ERR_R_INTERNAL_ERROR);
3156         goto err;
3157     }
3158 
3159     ret = 1;
3160  err:
3161     OPENSSL_free(encodedPoint);
3162     EVP_PKEY_free(ckey);
3163     return ret;
3164 #else
3165     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3166              ERR_R_INTERNAL_ERROR);
3167     return 0;
3168 #endif
3169 }
3170 
3171 static int tls_construct_cke_gost(SSL *s, WPACKET *pkt)
3172 {
3173 #ifndef OPENSSL_NO_GOST
3174     /* GOST key exchange message creation */
3175     EVP_PKEY_CTX *pkey_ctx = NULL;
3176     X509 *peer_cert;
3177     size_t msglen;
3178     unsigned int md_len;
3179     unsigned char shared_ukm[32], tmp[256];
3180     EVP_MD_CTX *ukm_hash = NULL;
3181     int dgst_nid = NID_id_GostR3411_94;
3182     unsigned char *pms = NULL;
3183     size_t pmslen = 0;
3184 
3185     if ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aGOST12) != 0)
3186         dgst_nid = NID_id_GostR3411_2012_256;
3187 
3188     /*
3189      * Get server certificate PKEY and create ctx from it
3190      */
3191     peer_cert = s->session->peer;
3192     if (!peer_cert) {
3193         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3194                SSL_R_NO_GOST_CERTIFICATE_SENT_BY_PEER);
3195         return 0;
3196     }
3197 
3198     pkey_ctx = EVP_PKEY_CTX_new(X509_get0_pubkey(peer_cert), NULL);
3199     if (pkey_ctx == NULL) {
3200         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3201                  ERR_R_MALLOC_FAILURE);
3202         return 0;
3203     }
3204     /*
3205      * If we have send a certificate, and certificate key
3206      * parameters match those of server certificate, use
3207      * certificate key for key exchange
3208      */
3209 
3210     /* Otherwise, generate ephemeral key pair */
3211     pmslen = 32;
3212     pms = OPENSSL_malloc(pmslen);
3213     if (pms == NULL) {
3214         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3215                  ERR_R_MALLOC_FAILURE);
3216         goto err;
3217     }
3218 
3219     if (EVP_PKEY_encrypt_init(pkey_ctx) <= 0
3220         /* Generate session key
3221          * TODO(size_t): Convert this function
3222          */
3223         || RAND_bytes(pms, (int)pmslen) <= 0) {
3224         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3225                  ERR_R_INTERNAL_ERROR);
3226         goto err;
3227     };
3228     /*
3229      * Compute shared IV and store it in algorithm-specific context
3230      * data
3231      */
3232     ukm_hash = EVP_MD_CTX_new();
3233     if (ukm_hash == NULL
3234         || EVP_DigestInit(ukm_hash, EVP_get_digestbynid(dgst_nid)) <= 0
3235         || EVP_DigestUpdate(ukm_hash, s->s3->client_random,
3236                             SSL3_RANDOM_SIZE) <= 0
3237         || EVP_DigestUpdate(ukm_hash, s->s3->server_random,
3238                             SSL3_RANDOM_SIZE) <= 0
3239         || EVP_DigestFinal_ex(ukm_hash, shared_ukm, &md_len) <= 0) {
3240         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3241                  ERR_R_INTERNAL_ERROR);
3242         goto err;
3243     }
3244     EVP_MD_CTX_free(ukm_hash);
3245     ukm_hash = NULL;
3246     if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, EVP_PKEY_OP_ENCRYPT,
3247                           EVP_PKEY_CTRL_SET_IV, 8, shared_ukm) < 0) {
3248         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3249                  SSL_R_LIBRARY_BUG);
3250         goto err;
3251     }
3252     /* Make GOST keytransport blob message */
3253     /*
3254      * Encapsulate it into sequence
3255      */
3256     msglen = 255;
3257     if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) <= 0) {
3258         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3259                  SSL_R_LIBRARY_BUG);
3260         goto err;
3261     }
3262 
3263     if (!WPACKET_put_bytes_u8(pkt, V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)
3264             || (msglen >= 0x80 && !WPACKET_put_bytes_u8(pkt, 0x81))
3265             || !WPACKET_sub_memcpy_u8(pkt, tmp, msglen)) {
3266         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3267                  ERR_R_INTERNAL_ERROR);
3268         goto err;
3269     }
3270 
3271     EVP_PKEY_CTX_free(pkey_ctx);
3272     s->s3->tmp.pms = pms;
3273     s->s3->tmp.pmslen = pmslen;
3274 
3275     return 1;
3276  err:
3277     EVP_PKEY_CTX_free(pkey_ctx);
3278     OPENSSL_clear_free(pms, pmslen);
3279     EVP_MD_CTX_free(ukm_hash);
3280     return 0;
3281 #else
3282     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3283              ERR_R_INTERNAL_ERROR);
3284     return 0;
3285 #endif
3286 }
3287 
3288 static int tls_construct_cke_srp(SSL *s, WPACKET *pkt)
3289 {
3290 #ifndef OPENSSL_NO_SRP
3291     unsigned char *abytes = NULL;
3292 
3293     if (s->srp_ctx.A == NULL
3294             || !WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(s->srp_ctx.A),
3295                                                &abytes)) {
3296         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3297                  ERR_R_INTERNAL_ERROR);
3298         return 0;
3299     }
3300     BN_bn2bin(s->srp_ctx.A, abytes);
3301 
3302     OPENSSL_free(s->session->srp_username);
3303     s->session->srp_username = OPENSSL_strdup(s->srp_ctx.login);
3304     if (s->session->srp_username == NULL) {
3305         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3306                  ERR_R_MALLOC_FAILURE);
3307         return 0;
3308     }
3309 
3310     return 1;
3311 #else
3312     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3313              ERR_R_INTERNAL_ERROR);
3314     return 0;
3315 #endif
3316 }
3317 
3318 int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt)
3319 {
3320     unsigned long alg_k;
3321 
3322     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3323 
3324     /*
3325      * All of the construct functions below call SSLfatal() if necessary so
3326      * no need to do so here.
3327      */
3328     if ((alg_k & SSL_PSK)
3329         && !tls_construct_cke_psk_preamble(s, pkt))
3330         goto err;
3331 
3332     if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
3333         if (!tls_construct_cke_rsa(s, pkt))
3334             goto err;
3335     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
3336         if (!tls_construct_cke_dhe(s, pkt))
3337             goto err;
3338     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
3339         if (!tls_construct_cke_ecdhe(s, pkt))
3340             goto err;
3341     } else if (alg_k & SSL_kGOST) {
3342         if (!tls_construct_cke_gost(s, pkt))
3343             goto err;
3344     } else if (alg_k & SSL_kSRP) {
3345         if (!tls_construct_cke_srp(s, pkt))
3346             goto err;
3347     } else if (!(alg_k & SSL_kPSK)) {
3348         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3349                  SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
3350         goto err;
3351     }
3352 
3353     return 1;
3354  err:
3355     OPENSSL_clear_free(s->s3->tmp.pms, s->s3->tmp.pmslen);
3356     s->s3->tmp.pms = NULL;
3357     s->s3->tmp.pmslen = 0;
3358 #ifndef OPENSSL_NO_PSK
3359     OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);
3360     s->s3->tmp.psk = NULL;
3361     s->s3->tmp.psklen = 0;
3362 #endif
3363     return 0;
3364 }
3365 
3366 int tls_client_key_exchange_post_work(SSL *s)
3367 {
3368     unsigned char *pms = NULL;
3369     size_t pmslen = 0;
3370 
3371     pms = s->s3->tmp.pms;
3372     pmslen = s->s3->tmp.pmslen;
3373 
3374 #ifndef OPENSSL_NO_SRP
3375     /* Check for SRP */
3376     if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
3377         if (!srp_generate_client_master_secret(s)) {
3378             /* SSLfatal() already called */
3379             goto err;
3380         }
3381         return 1;
3382     }
3383 #endif
3384 
3385     if (pms == NULL && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
3386         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3387                  SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK, ERR_R_MALLOC_FAILURE);
3388         goto err;
3389     }
3390     if (!ssl_generate_master_secret(s, pms, pmslen, 1)) {
3391         /* SSLfatal() already called */
3392         /* ssl_generate_master_secret frees the pms even on error */
3393         pms = NULL;
3394         pmslen = 0;
3395         goto err;
3396     }
3397     pms = NULL;
3398     pmslen = 0;
3399 
3400 #ifndef OPENSSL_NO_SCTP
3401     if (SSL_IS_DTLS(s)) {
3402         unsigned char sctpauthkey[64];
3403         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
3404         size_t labellen;
3405 
3406         /*
3407          * Add new shared key for SCTP-Auth, will be ignored if no SCTP
3408          * used.
3409          */
3410         memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
3411                sizeof(DTLS1_SCTP_AUTH_LABEL));
3412 
3413         /* Don't include the terminating zero. */
3414         labellen = sizeof(labelbuffer) - 1;
3415         if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
3416             labellen += 1;
3417 
3418         if (SSL_export_keying_material(s, sctpauthkey,
3419                                        sizeof(sctpauthkey), labelbuffer,
3420                                        labellen, NULL, 0, 0) <= 0) {
3421             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3422                      SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK,
3423                      ERR_R_INTERNAL_ERROR);
3424             goto err;
3425         }
3426 
3427         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
3428                  sizeof(sctpauthkey), sctpauthkey);
3429     }
3430 #endif
3431 
3432     return 1;
3433  err:
3434     OPENSSL_clear_free(pms, pmslen);
3435     s->s3->tmp.pms = NULL;
3436     s->s3->tmp.pmslen = 0;
3437     return 0;
3438 }
3439 
3440 /*
3441  * Check a certificate can be used for client authentication. Currently check
3442  * cert exists, if we have a suitable digest for TLS 1.2 if static DH client
3443  * certificates can be used and optionally checks suitability for Suite B.
3444  */
3445 static int ssl3_check_client_certificate(SSL *s)
3446 {
3447     /* If no suitable signature algorithm can't use certificate */
3448     if (!tls_choose_sigalg(s, 0) || s->s3->tmp.sigalg == NULL)
3449         return 0;
3450     /*
3451      * If strict mode check suitability of chain before using it. This also
3452      * adjusts suite B digest if necessary.
3453      */
3454     if (s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT &&
3455         !tls1_check_chain(s, NULL, NULL, NULL, -2))
3456         return 0;
3457     return 1;
3458 }
3459 
3460 WORK_STATE tls_prepare_client_certificate(SSL *s, WORK_STATE wst)
3461 {
3462     X509 *x509 = NULL;
3463     EVP_PKEY *pkey = NULL;
3464     int i;
3465 
3466     if (wst == WORK_MORE_A) {
3467         /* Let cert callback update client certificates if required */
3468         if (s->cert->cert_cb) {
3469             i = s->cert->cert_cb(s, s->cert->cert_cb_arg);
3470             if (i < 0) {
3471                 s->rwstate = SSL_X509_LOOKUP;
3472                 return WORK_MORE_A;
3473             }
3474             if (i == 0) {
3475                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3476                          SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3477                          SSL_R_CALLBACK_FAILED);
3478                 return WORK_ERROR;
3479             }
3480             s->rwstate = SSL_NOTHING;
3481         }
3482         if (ssl3_check_client_certificate(s)) {
3483             if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
3484                 return WORK_FINISHED_STOP;
3485             }
3486             return WORK_FINISHED_CONTINUE;
3487         }
3488 
3489         /* Fall through to WORK_MORE_B */
3490         wst = WORK_MORE_B;
3491     }
3492 
3493     /* We need to get a client cert */
3494     if (wst == WORK_MORE_B) {
3495         /*
3496          * If we get an error, we need to ssl->rwstate=SSL_X509_LOOKUP;
3497          * return(-1); We then get retied later
3498          */
3499         i = ssl_do_client_cert_cb(s, &x509, &pkey);
3500         if (i < 0) {
3501             s->rwstate = SSL_X509_LOOKUP;
3502             return WORK_MORE_B;
3503         }
3504         s->rwstate = SSL_NOTHING;
3505         if ((i == 1) && (pkey != NULL) && (x509 != NULL)) {
3506             if (!SSL_use_certificate(s, x509) || !SSL_use_PrivateKey(s, pkey))
3507                 i = 0;
3508         } else if (i == 1) {
3509             i = 0;
3510             SSLerr(SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3511                    SSL_R_BAD_DATA_RETURNED_BY_CALLBACK);
3512         }
3513 
3514         X509_free(x509);
3515         EVP_PKEY_free(pkey);
3516         if (i && !ssl3_check_client_certificate(s))
3517             i = 0;
3518         if (i == 0) {
3519             if (s->version == SSL3_VERSION) {
3520                 s->s3->tmp.cert_req = 0;
3521                 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_CERTIFICATE);
3522                 return WORK_FINISHED_CONTINUE;
3523             } else {
3524                 s->s3->tmp.cert_req = 2;
3525                 if (!ssl3_digest_cached_records(s, 0)) {
3526                     /* SSLfatal() already called */
3527                     return WORK_ERROR;
3528                 }
3529             }
3530         }
3531 
3532         if (s->post_handshake_auth == SSL_PHA_REQUESTED)
3533             return WORK_FINISHED_STOP;
3534         return WORK_FINISHED_CONTINUE;
3535     }
3536 
3537     /* Shouldn't ever get here */
3538     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3539              ERR_R_INTERNAL_ERROR);
3540     return WORK_ERROR;
3541 }
3542 
3543 int tls_construct_client_certificate(SSL *s, WPACKET *pkt)
3544 {
3545     if (SSL_IS_TLS13(s)) {
3546         if (s->pha_context == NULL) {
3547             /* no context available, add 0-length context */
3548             if (!WPACKET_put_bytes_u8(pkt, 0)) {
3549                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3550                          SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
3551                 return 0;
3552             }
3553         } else if (!WPACKET_sub_memcpy_u8(pkt, s->pha_context, s->pha_context_len)) {
3554             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3555                      SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
3556             return 0;
3557         }
3558     }
3559     if (!ssl3_output_cert_chain(s, pkt,
3560                                 (s->s3->tmp.cert_req == 2) ? NULL
3561                                                            : s->cert->key)) {
3562         /* SSLfatal() already called */
3563         return 0;
3564     }
3565 
3566     if (SSL_IS_TLS13(s)
3567             && SSL_IS_FIRST_HANDSHAKE(s)
3568             && (!s->method->ssl3_enc->change_cipher_state(s,
3569                     SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_WRITE))) {
3570         /*
3571          * This is a fatal error, which leaves enc_write_ctx in an inconsistent
3572          * state and thus ssl3_send_alert may crash.
3573          */
3574         SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE,
3575                  SSL_R_CANNOT_CHANGE_CIPHER);
3576         return 0;
3577     }
3578 
3579     return 1;
3580 }
3581 
3582 int ssl3_check_cert_and_algorithm(SSL *s)
3583 {
3584     const SSL_CERT_LOOKUP *clu;
3585     size_t idx;
3586     long alg_k, alg_a;
3587 
3588     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3589     alg_a = s->s3->tmp.new_cipher->algorithm_auth;
3590 
3591     /* we don't have a certificate */
3592     if (!(alg_a & SSL_aCERT))
3593         return 1;
3594 
3595     /* This is the passed certificate */
3596     clu = ssl_cert_lookup_by_pkey(X509_get0_pubkey(s->session->peer), &idx);
3597 
3598     /* Check certificate is recognised and suitable for cipher */
3599     if (clu == NULL || (alg_a & clu->amask) == 0) {
3600         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3601                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3602                  SSL_R_MISSING_SIGNING_CERT);
3603         return 0;
3604     }
3605 
3606 #ifndef OPENSSL_NO_EC
3607     if (clu->amask & SSL_aECDSA) {
3608         if (ssl_check_srvr_ecc_cert_and_alg(s->session->peer, s))
3609             return 1;
3610         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3611                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM, SSL_R_BAD_ECC_CERT);
3612         return 0;
3613     }
3614 #endif
3615 #ifndef OPENSSL_NO_RSA
3616     if (alg_k & (SSL_kRSA | SSL_kRSAPSK) && idx != SSL_PKEY_RSA) {
3617         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3618                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3619                  SSL_R_MISSING_RSA_ENCRYPTING_CERT);
3620         return 0;
3621     }
3622 #endif
3623 #ifndef OPENSSL_NO_DH
3624     if ((alg_k & SSL_kDHE) && (s->s3->peer_tmp == NULL)) {
3625         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3626                  ERR_R_INTERNAL_ERROR);
3627         return 0;
3628     }
3629 #endif
3630 
3631     return 1;
3632 }
3633 
3634 #ifndef OPENSSL_NO_NEXTPROTONEG
3635 int tls_construct_next_proto(SSL *s, WPACKET *pkt)
3636 {
3637     size_t len, padding_len;
3638     unsigned char *padding = NULL;
3639 
3640     len = s->ext.npn_len;
3641     padding_len = 32 - ((len + 2) % 32);
3642 
3643     if (!WPACKET_sub_memcpy_u8(pkt, s->ext.npn, len)
3644             || !WPACKET_sub_allocate_bytes_u8(pkt, padding_len, &padding)) {
3645         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_NEXT_PROTO,
3646                  ERR_R_INTERNAL_ERROR);
3647         return 0;
3648     }
3649 
3650     memset(padding, 0, padding_len);
3651 
3652     return 1;
3653 }
3654 #endif
3655 
3656 MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt)
3657 {
3658     if (PACKET_remaining(pkt) > 0) {
3659         /* should contain no data */
3660         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_HELLO_REQ,
3661                  SSL_R_LENGTH_MISMATCH);
3662         return MSG_PROCESS_ERROR;
3663     }
3664 
3665     if ((s->options & SSL_OP_NO_RENEGOTIATION)) {
3666         ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
3667         return MSG_PROCESS_FINISHED_READING;
3668     }
3669 
3670     /*
3671      * This is a historical discrepancy (not in the RFC) maintained for
3672      * compatibility reasons. If a TLS client receives a HelloRequest it will
3673      * attempt an abbreviated handshake. However if a DTLS client receives a
3674      * HelloRequest it will do a full handshake. Either behaviour is reasonable
3675      * but doing one for TLS and another for DTLS is odd.
3676      */
3677     if (SSL_IS_DTLS(s))
3678         SSL_renegotiate(s);
3679     else
3680         SSL_renegotiate_abbreviated(s);
3681 
3682     return MSG_PROCESS_FINISHED_READING;
3683 }
3684 
3685 static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
3686 {
3687     PACKET extensions;
3688     RAW_EXTENSION *rawexts = NULL;
3689 
3690     if (!PACKET_as_length_prefixed_2(pkt, &extensions)
3691             || PACKET_remaining(pkt) != 0) {
3692         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS,
3693                  SSL_R_LENGTH_MISMATCH);
3694         goto err;
3695     }
3696 
3697     if (!tls_collect_extensions(s, &extensions,
3698                                 SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, &rawexts,
3699                                 NULL, 1)
3700             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
3701                                          rawexts, NULL, 0, 1)) {
3702         /* SSLfatal() already called */
3703         goto err;
3704     }
3705 
3706     OPENSSL_free(rawexts);
3707     return MSG_PROCESS_CONTINUE_READING;
3708 
3709  err:
3710     OPENSSL_free(rawexts);
3711     return MSG_PROCESS_ERROR;
3712 }
3713 
3714 int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
3715 {
3716     int i = 0;
3717 #ifndef OPENSSL_NO_ENGINE
3718     if (s->ctx->client_cert_engine) {
3719         i = ENGINE_load_ssl_client_cert(s->ctx->client_cert_engine, s,
3720                                         SSL_get_client_CA_list(s),
3721                                         px509, ppkey, NULL, NULL, NULL);
3722         if (i != 0)
3723             return i;
3724     }
3725 #endif
3726     if (s->ctx->client_cert_cb)
3727         i = s->ctx->client_cert_cb(s, px509, ppkey);
3728     return i;
3729 }
3730 
3731 int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, WPACKET *pkt)
3732 {
3733     int i;
3734     size_t totlen = 0, len, maxlen, maxverok = 0;
3735     int empty_reneg_info_scsv = !s->renegotiate;
3736 
3737     /* Set disabled masks for this session */
3738     if (!ssl_set_client_disabled(s)) {
3739         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3740                  SSL_R_NO_PROTOCOLS_AVAILABLE);
3741         return 0;
3742     }
3743 
3744     if (sk == NULL) {
3745         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3746                  ERR_R_INTERNAL_ERROR);
3747         return 0;
3748     }
3749 
3750 #ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
3751 # if OPENSSL_MAX_TLS1_2_CIPHER_LENGTH < 6
3752 #  error Max cipher length too short
3753 # endif
3754     /*
3755      * Some servers hang if client hello > 256 bytes as hack workaround
3756      * chop number of supported ciphers to keep it well below this if we
3757      * use TLS v1.2
3758      */
3759     if (TLS1_get_version(s) >= TLS1_2_VERSION)
3760         maxlen = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
3761     else
3762 #endif
3763         /* Maximum length that can be stored in 2 bytes. Length must be even */
3764         maxlen = 0xfffe;
3765 
3766     if (empty_reneg_info_scsv)
3767         maxlen -= 2;
3768     if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV)
3769         maxlen -= 2;
3770 
3771     for (i = 0; i < sk_SSL_CIPHER_num(sk) && totlen < maxlen; i++) {
3772         const SSL_CIPHER *c;
3773 
3774         c = sk_SSL_CIPHER_value(sk, i);
3775         /* Skip disabled ciphers */
3776         if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0))
3777             continue;
3778 
3779         if (!s->method->put_cipher_by_char(c, pkt, &len)) {
3780             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3781                      ERR_R_INTERNAL_ERROR);
3782             return 0;
3783         }
3784 
3785         /* Sanity check that the maximum version we offer has ciphers enabled */
3786         if (!maxverok) {
3787             if (SSL_IS_DTLS(s)) {
3788                 if (DTLS_VERSION_GE(c->max_dtls, s->s3->tmp.max_ver)
3789                         && DTLS_VERSION_LE(c->min_dtls, s->s3->tmp.max_ver))
3790                     maxverok = 1;
3791             } else {
3792                 if (c->max_tls >= s->s3->tmp.max_ver
3793                         && c->min_tls <= s->s3->tmp.max_ver)
3794                     maxverok = 1;
3795             }
3796         }
3797 
3798         totlen += len;
3799     }
3800 
3801     if (totlen == 0 || !maxverok) {
3802         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3803                  SSL_R_NO_CIPHERS_AVAILABLE);
3804 
3805         if (!maxverok)
3806             ERR_add_error_data(1, "No ciphers enabled for max supported "
3807                                   "SSL/TLS version");
3808 
3809         return 0;
3810     }
3811 
3812     if (totlen != 0) {
3813         if (empty_reneg_info_scsv) {
3814             static SSL_CIPHER scsv = {
3815                 0, NULL, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
3816             };
3817             if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
3818                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3819                          SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
3820                 return 0;
3821             }
3822         }
3823         if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
3824             static SSL_CIPHER scsv = {
3825                 0, NULL, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
3826             };
3827             if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
3828                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3829                          SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
3830                 return 0;
3831             }
3832         }
3833     }
3834 
3835     return 1;
3836 }
3837 
3838 int tls_construct_end_of_early_data(SSL *s, WPACKET *pkt)
3839 {
3840     if (s->early_data_state != SSL_EARLY_DATA_WRITE_RETRY
3841             && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING) {
3842         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3843                  SSL_F_TLS_CONSTRUCT_END_OF_EARLY_DATA,
3844                  ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
3845         return 0;
3846     }
3847 
3848     s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
3849     return 1;
3850 }
3851