xref: /freebsd/crypto/openssl/ssl/statem/statem_clnt.c (revision 54e9e4e72d711fb41f88f793f6c64df1126112f9)
1 /*
2  * Copyright 1995-2019 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_locl.h"
16 #include "statem_locl.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         if (s->key_update != SSL_KEY_UPDATE_NONE) {
477             st->hand_state = TLS_ST_CW_KEY_UPDATE;
478             return WRITE_TRAN_CONTINUE;
479         }
480         /* Fall through */
481 
482     case TLS_ST_CW_KEY_UPDATE:
483     case TLS_ST_CR_SESSION_TICKET:
484     case TLS_ST_CW_FINISHED:
485         st->hand_state = TLS_ST_OK;
486         return WRITE_TRAN_CONTINUE;
487 
488     case TLS_ST_OK:
489         if (s->key_update != SSL_KEY_UPDATE_NONE) {
490             st->hand_state = TLS_ST_CW_KEY_UPDATE;
491             return WRITE_TRAN_CONTINUE;
492         }
493 
494         /* Try to read from the server instead */
495         return WRITE_TRAN_FINISHED;
496     }
497 }
498 
499 /*
500  * ossl_statem_client_write_transition() works out what handshake state to
501  * move to next when the client is writing messages to be sent to the server.
502  */
503 WRITE_TRAN ossl_statem_client_write_transition(SSL *s)
504 {
505     OSSL_STATEM *st = &s->statem;
506 
507     /*
508      * Note that immediately before/after a ClientHello we don't know what
509      * version we are going to negotiate yet, so we don't take this branch until
510      * later
511      */
512     if (SSL_IS_TLS13(s))
513         return ossl_statem_client13_write_transition(s);
514 
515     switch (st->hand_state) {
516     default:
517         /* Shouldn't happen */
518         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
519                  SSL_F_OSSL_STATEM_CLIENT_WRITE_TRANSITION,
520                  ERR_R_INTERNAL_ERROR);
521         return WRITE_TRAN_ERROR;
522 
523     case TLS_ST_OK:
524         if (!s->renegotiate) {
525             /*
526              * We haven't requested a renegotiation ourselves so we must have
527              * received a message from the server. Better read it.
528              */
529             return WRITE_TRAN_FINISHED;
530         }
531         /* Renegotiation */
532         /* fall thru */
533     case TLS_ST_BEFORE:
534         st->hand_state = TLS_ST_CW_CLNT_HELLO;
535         return WRITE_TRAN_CONTINUE;
536 
537     case TLS_ST_CW_CLNT_HELLO:
538         if (s->early_data_state == SSL_EARLY_DATA_CONNECTING) {
539             /*
540              * We are assuming this is a TLSv1.3 connection, although we haven't
541              * actually selected a version yet.
542              */
543             if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0)
544                 st->hand_state = TLS_ST_CW_CHANGE;
545             else
546                 st->hand_state = TLS_ST_EARLY_DATA;
547             return WRITE_TRAN_CONTINUE;
548         }
549         /*
550          * No transition at the end of writing because we don't know what
551          * we will be sent
552          */
553         return WRITE_TRAN_FINISHED;
554 
555     case TLS_ST_CR_SRVR_HELLO:
556         /*
557          * We only get here in TLSv1.3. We just received an HRR, so issue a
558          * CCS unless middlebox compat mode is off, or we already issued one
559          * because we did early data.
560          */
561         if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0
562                 && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING)
563             st->hand_state = TLS_ST_CW_CHANGE;
564         else
565             st->hand_state = TLS_ST_CW_CLNT_HELLO;
566         return WRITE_TRAN_CONTINUE;
567 
568     case TLS_ST_EARLY_DATA:
569         return WRITE_TRAN_FINISHED;
570 
571     case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
572         st->hand_state = TLS_ST_CW_CLNT_HELLO;
573         return WRITE_TRAN_CONTINUE;
574 
575     case TLS_ST_CR_SRVR_DONE:
576         if (s->s3->tmp.cert_req)
577             st->hand_state = TLS_ST_CW_CERT;
578         else
579             st->hand_state = TLS_ST_CW_KEY_EXCH;
580         return WRITE_TRAN_CONTINUE;
581 
582     case TLS_ST_CW_CERT:
583         st->hand_state = TLS_ST_CW_KEY_EXCH;
584         return WRITE_TRAN_CONTINUE;
585 
586     case TLS_ST_CW_KEY_EXCH:
587         /*
588          * For TLS, cert_req is set to 2, so a cert chain of nothing is
589          * sent, but no verify packet is sent
590          */
591         /*
592          * XXX: For now, we do not support client authentication in ECDH
593          * cipher suites with ECDH (rather than ECDSA) certificates. We
594          * need to skip the certificate verify message when client's
595          * ECDH public key is sent inside the client certificate.
596          */
597         if (s->s3->tmp.cert_req == 1) {
598             st->hand_state = TLS_ST_CW_CERT_VRFY;
599         } else {
600             st->hand_state = TLS_ST_CW_CHANGE;
601         }
602         if (s->s3->flags & TLS1_FLAGS_SKIP_CERT_VERIFY) {
603             st->hand_state = TLS_ST_CW_CHANGE;
604         }
605         return WRITE_TRAN_CONTINUE;
606 
607     case TLS_ST_CW_CERT_VRFY:
608         st->hand_state = TLS_ST_CW_CHANGE;
609         return WRITE_TRAN_CONTINUE;
610 
611     case TLS_ST_CW_CHANGE:
612         if (s->hello_retry_request == SSL_HRR_PENDING) {
613             st->hand_state = TLS_ST_CW_CLNT_HELLO;
614         } else if (s->early_data_state == SSL_EARLY_DATA_CONNECTING) {
615             st->hand_state = TLS_ST_EARLY_DATA;
616         } else {
617 #if defined(OPENSSL_NO_NEXTPROTONEG)
618             st->hand_state = TLS_ST_CW_FINISHED;
619 #else
620             if (!SSL_IS_DTLS(s) && s->s3->npn_seen)
621                 st->hand_state = TLS_ST_CW_NEXT_PROTO;
622             else
623                 st->hand_state = TLS_ST_CW_FINISHED;
624 #endif
625         }
626         return WRITE_TRAN_CONTINUE;
627 
628 #if !defined(OPENSSL_NO_NEXTPROTONEG)
629     case TLS_ST_CW_NEXT_PROTO:
630         st->hand_state = TLS_ST_CW_FINISHED;
631         return WRITE_TRAN_CONTINUE;
632 #endif
633 
634     case TLS_ST_CW_FINISHED:
635         if (s->hit) {
636             st->hand_state = TLS_ST_OK;
637             return WRITE_TRAN_CONTINUE;
638         } else {
639             return WRITE_TRAN_FINISHED;
640         }
641 
642     case TLS_ST_CR_FINISHED:
643         if (s->hit) {
644             st->hand_state = TLS_ST_CW_CHANGE;
645             return WRITE_TRAN_CONTINUE;
646         } else {
647             st->hand_state = TLS_ST_OK;
648             return WRITE_TRAN_CONTINUE;
649         }
650 
651     case TLS_ST_CR_HELLO_REQ:
652         /*
653          * If we can renegotiate now then do so, otherwise wait for a more
654          * convenient time.
655          */
656         if (ssl3_renegotiate_check(s, 1)) {
657             if (!tls_setup_handshake(s)) {
658                 /* SSLfatal() already called */
659                 return WRITE_TRAN_ERROR;
660             }
661             st->hand_state = TLS_ST_CW_CLNT_HELLO;
662             return WRITE_TRAN_CONTINUE;
663         }
664         st->hand_state = TLS_ST_OK;
665         return WRITE_TRAN_CONTINUE;
666     }
667 }
668 
669 /*
670  * Perform any pre work that needs to be done prior to sending a message from
671  * the client to the server.
672  */
673 WORK_STATE ossl_statem_client_pre_work(SSL *s, WORK_STATE wst)
674 {
675     OSSL_STATEM *st = &s->statem;
676 
677     switch (st->hand_state) {
678     default:
679         /* No pre work to be done */
680         break;
681 
682     case TLS_ST_CW_CLNT_HELLO:
683         s->shutdown = 0;
684         if (SSL_IS_DTLS(s)) {
685             /* every DTLS ClientHello resets Finished MAC */
686             if (!ssl3_init_finished_mac(s)) {
687                 /* SSLfatal() already called */
688                 return WORK_ERROR;
689             }
690         }
691         break;
692 
693     case TLS_ST_CW_CHANGE:
694         if (SSL_IS_DTLS(s)) {
695             if (s->hit) {
696                 /*
697                  * We're into the last flight so we don't retransmit these
698                  * messages unless we need to.
699                  */
700                 st->use_timer = 0;
701             }
702 #ifndef OPENSSL_NO_SCTP
703             if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
704                 /* Calls SSLfatal() as required */
705                 return dtls_wait_for_dry(s);
706             }
707 #endif
708         }
709         break;
710 
711     case TLS_ST_PENDING_EARLY_DATA_END:
712         /*
713          * If we've been called by SSL_do_handshake()/SSL_write(), or we did not
714          * attempt to write early data before calling SSL_read() then we press
715          * on with the handshake. Otherwise we pause here.
716          */
717         if (s->early_data_state == SSL_EARLY_DATA_FINISHED_WRITING
718                 || s->early_data_state == SSL_EARLY_DATA_NONE)
719             return WORK_FINISHED_CONTINUE;
720         /* Fall through */
721 
722     case TLS_ST_EARLY_DATA:
723         return tls_finish_handshake(s, wst, 0, 1);
724 
725     case TLS_ST_OK:
726         /* Calls SSLfatal() as required */
727         return tls_finish_handshake(s, wst, 1, 1);
728     }
729 
730     return WORK_FINISHED_CONTINUE;
731 }
732 
733 /*
734  * Perform any work that needs to be done after sending a message from the
735  * client to the server.
736  */
737 WORK_STATE ossl_statem_client_post_work(SSL *s, WORK_STATE wst)
738 {
739     OSSL_STATEM *st = &s->statem;
740 
741     s->init_num = 0;
742 
743     switch (st->hand_state) {
744     default:
745         /* No post work to be done */
746         break;
747 
748     case TLS_ST_CW_CLNT_HELLO:
749         if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
750                 && s->max_early_data > 0) {
751             /*
752              * We haven't selected TLSv1.3 yet so we don't call the change
753              * cipher state function associated with the SSL_METHOD. Instead
754              * we call tls13_change_cipher_state() directly.
755              */
756             if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) == 0) {
757                 if (!tls13_change_cipher_state(s,
758                             SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
759                     /* SSLfatal() already called */
760                     return WORK_ERROR;
761                 }
762             }
763             /* else we're in compat mode so we delay flushing until after CCS */
764         } else if (!statem_flush(s)) {
765             return WORK_MORE_A;
766         }
767 
768         if (SSL_IS_DTLS(s)) {
769             /* Treat the next message as the first packet */
770             s->first_packet = 1;
771         }
772         break;
773 
774     case TLS_ST_CW_END_OF_EARLY_DATA:
775         /*
776          * We set the enc_write_ctx back to NULL because we may end up writing
777          * in cleartext again if we get a HelloRetryRequest from the server.
778          */
779         EVP_CIPHER_CTX_free(s->enc_write_ctx);
780         s->enc_write_ctx = NULL;
781         break;
782 
783     case TLS_ST_CW_KEY_EXCH:
784         if (tls_client_key_exchange_post_work(s) == 0) {
785             /* SSLfatal() already called */
786             return WORK_ERROR;
787         }
788         break;
789 
790     case TLS_ST_CW_CHANGE:
791         if (SSL_IS_TLS13(s) || s->hello_retry_request == SSL_HRR_PENDING)
792             break;
793         if (s->early_data_state == SSL_EARLY_DATA_CONNECTING
794                     && s->max_early_data > 0) {
795             /*
796              * We haven't selected TLSv1.3 yet so we don't call the change
797              * cipher state function associated with the SSL_METHOD. Instead
798              * we call tls13_change_cipher_state() directly.
799              */
800             if (!tls13_change_cipher_state(s,
801                         SSL3_CC_EARLY | SSL3_CHANGE_CIPHER_CLIENT_WRITE))
802                 return WORK_ERROR;
803             break;
804         }
805         s->session->cipher = s->s3->tmp.new_cipher;
806 #ifdef OPENSSL_NO_COMP
807         s->session->compress_meth = 0;
808 #else
809         if (s->s3->tmp.new_compression == NULL)
810             s->session->compress_meth = 0;
811         else
812             s->session->compress_meth = s->s3->tmp.new_compression->id;
813 #endif
814         if (!s->method->ssl3_enc->setup_key_block(s)) {
815             /* SSLfatal() already called */
816             return WORK_ERROR;
817         }
818 
819         if (!s->method->ssl3_enc->change_cipher_state(s,
820                                           SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
821             /* SSLfatal() already called */
822             return WORK_ERROR;
823         }
824 
825         if (SSL_IS_DTLS(s)) {
826 #ifndef OPENSSL_NO_SCTP
827             if (s->hit) {
828                 /*
829                  * Change to new shared key of SCTP-Auth, will be ignored if
830                  * no SCTP used.
831                  */
832                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
833                          0, NULL);
834             }
835 #endif
836 
837             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
838         }
839         break;
840 
841     case TLS_ST_CW_FINISHED:
842 #ifndef OPENSSL_NO_SCTP
843         if (wst == WORK_MORE_A && SSL_IS_DTLS(s) && s->hit == 0) {
844             /*
845              * Change to new shared key of SCTP-Auth, will be ignored if
846              * no SCTP used.
847              */
848             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
849                      0, NULL);
850         }
851 #endif
852         if (statem_flush(s) != 1)
853             return WORK_MORE_B;
854 
855         if (SSL_IS_TLS13(s)) {
856             if (!tls13_save_handshake_digest_for_pha(s)) {
857                 /* SSLfatal() already called */
858                 return WORK_ERROR;
859             }
860             if (s->post_handshake_auth != SSL_PHA_REQUESTED) {
861                 if (!s->method->ssl3_enc->change_cipher_state(s,
862                         SSL3_CC_APPLICATION | SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
863                     /* SSLfatal() already called */
864                     return WORK_ERROR;
865                 }
866             }
867         }
868         break;
869 
870     case TLS_ST_CW_KEY_UPDATE:
871         if (statem_flush(s) != 1)
872             return WORK_MORE_A;
873         if (!tls13_update_key(s, 1)) {
874             /* SSLfatal() already called */
875             return WORK_ERROR;
876         }
877         break;
878     }
879 
880     return WORK_FINISHED_CONTINUE;
881 }
882 
883 /*
884  * Get the message construction function and message type for sending from the
885  * client
886  *
887  * Valid return values are:
888  *   1: Success
889  *   0: Error
890  */
891 int ossl_statem_client_construct_message(SSL *s, WPACKET *pkt,
892                                          confunc_f *confunc, int *mt)
893 {
894     OSSL_STATEM *st = &s->statem;
895 
896     switch (st->hand_state) {
897     default:
898         /* Shouldn't happen */
899         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
900                  SSL_F_OSSL_STATEM_CLIENT_CONSTRUCT_MESSAGE,
901                  SSL_R_BAD_HANDSHAKE_STATE);
902         return 0;
903 
904     case TLS_ST_CW_CHANGE:
905         if (SSL_IS_DTLS(s))
906             *confunc = dtls_construct_change_cipher_spec;
907         else
908             *confunc = tls_construct_change_cipher_spec;
909         *mt = SSL3_MT_CHANGE_CIPHER_SPEC;
910         break;
911 
912     case TLS_ST_CW_CLNT_HELLO:
913         *confunc = tls_construct_client_hello;
914         *mt = SSL3_MT_CLIENT_HELLO;
915         break;
916 
917     case TLS_ST_CW_END_OF_EARLY_DATA:
918         *confunc = tls_construct_end_of_early_data;
919         *mt = SSL3_MT_END_OF_EARLY_DATA;
920         break;
921 
922     case TLS_ST_PENDING_EARLY_DATA_END:
923         *confunc = NULL;
924         *mt = SSL3_MT_DUMMY;
925         break;
926 
927     case TLS_ST_CW_CERT:
928         *confunc = tls_construct_client_certificate;
929         *mt = SSL3_MT_CERTIFICATE;
930         break;
931 
932     case TLS_ST_CW_KEY_EXCH:
933         *confunc = tls_construct_client_key_exchange;
934         *mt = SSL3_MT_CLIENT_KEY_EXCHANGE;
935         break;
936 
937     case TLS_ST_CW_CERT_VRFY:
938         *confunc = tls_construct_cert_verify;
939         *mt = SSL3_MT_CERTIFICATE_VERIFY;
940         break;
941 
942 #if !defined(OPENSSL_NO_NEXTPROTONEG)
943     case TLS_ST_CW_NEXT_PROTO:
944         *confunc = tls_construct_next_proto;
945         *mt = SSL3_MT_NEXT_PROTO;
946         break;
947 #endif
948     case TLS_ST_CW_FINISHED:
949         *confunc = tls_construct_finished;
950         *mt = SSL3_MT_FINISHED;
951         break;
952 
953     case TLS_ST_CW_KEY_UPDATE:
954         *confunc = tls_construct_key_update;
955         *mt = SSL3_MT_KEY_UPDATE;
956         break;
957     }
958 
959     return 1;
960 }
961 
962 /*
963  * Returns the maximum allowed length for the current message that we are
964  * reading. Excludes the message header.
965  */
966 size_t ossl_statem_client_max_message_size(SSL *s)
967 {
968     OSSL_STATEM *st = &s->statem;
969 
970     switch (st->hand_state) {
971     default:
972         /* Shouldn't happen */
973         return 0;
974 
975     case TLS_ST_CR_SRVR_HELLO:
976         return SERVER_HELLO_MAX_LENGTH;
977 
978     case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
979         return HELLO_VERIFY_REQUEST_MAX_LENGTH;
980 
981     case TLS_ST_CR_CERT:
982         return s->max_cert_list;
983 
984     case TLS_ST_CR_CERT_VRFY:
985         return SSL3_RT_MAX_PLAIN_LENGTH;
986 
987     case TLS_ST_CR_CERT_STATUS:
988         return SSL3_RT_MAX_PLAIN_LENGTH;
989 
990     case TLS_ST_CR_KEY_EXCH:
991         return SERVER_KEY_EXCH_MAX_LENGTH;
992 
993     case TLS_ST_CR_CERT_REQ:
994         /*
995          * Set to s->max_cert_list for compatibility with previous releases. In
996          * practice these messages can get quite long if servers are configured
997          * to provide a long list of acceptable CAs
998          */
999         return s->max_cert_list;
1000 
1001     case TLS_ST_CR_SRVR_DONE:
1002         return SERVER_HELLO_DONE_MAX_LENGTH;
1003 
1004     case TLS_ST_CR_CHANGE:
1005         if (s->version == DTLS1_BAD_VER)
1006             return 3;
1007         return CCS_MAX_LENGTH;
1008 
1009     case TLS_ST_CR_SESSION_TICKET:
1010         return SSL3_RT_MAX_PLAIN_LENGTH;
1011 
1012     case TLS_ST_CR_FINISHED:
1013         return FINISHED_MAX_LENGTH;
1014 
1015     case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
1016         return ENCRYPTED_EXTENSIONS_MAX_LENGTH;
1017 
1018     case TLS_ST_CR_KEY_UPDATE:
1019         return KEY_UPDATE_MAX_LENGTH;
1020     }
1021 }
1022 
1023 /*
1024  * Process a message that the client has been received from the server.
1025  */
1026 MSG_PROCESS_RETURN ossl_statem_client_process_message(SSL *s, PACKET *pkt)
1027 {
1028     OSSL_STATEM *st = &s->statem;
1029 
1030     switch (st->hand_state) {
1031     default:
1032         /* Shouldn't happen */
1033         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1034                  SSL_F_OSSL_STATEM_CLIENT_PROCESS_MESSAGE,
1035                  ERR_R_INTERNAL_ERROR);
1036         return MSG_PROCESS_ERROR;
1037 
1038     case TLS_ST_CR_SRVR_HELLO:
1039         return tls_process_server_hello(s, pkt);
1040 
1041     case DTLS_ST_CR_HELLO_VERIFY_REQUEST:
1042         return dtls_process_hello_verify(s, pkt);
1043 
1044     case TLS_ST_CR_CERT:
1045         return tls_process_server_certificate(s, pkt);
1046 
1047     case TLS_ST_CR_CERT_VRFY:
1048         return tls_process_cert_verify(s, pkt);
1049 
1050     case TLS_ST_CR_CERT_STATUS:
1051         return tls_process_cert_status(s, pkt);
1052 
1053     case TLS_ST_CR_KEY_EXCH:
1054         return tls_process_key_exchange(s, pkt);
1055 
1056     case TLS_ST_CR_CERT_REQ:
1057         return tls_process_certificate_request(s, pkt);
1058 
1059     case TLS_ST_CR_SRVR_DONE:
1060         return tls_process_server_done(s, pkt);
1061 
1062     case TLS_ST_CR_CHANGE:
1063         return tls_process_change_cipher_spec(s, pkt);
1064 
1065     case TLS_ST_CR_SESSION_TICKET:
1066         return tls_process_new_session_ticket(s, pkt);
1067 
1068     case TLS_ST_CR_FINISHED:
1069         return tls_process_finished(s, pkt);
1070 
1071     case TLS_ST_CR_HELLO_REQ:
1072         return tls_process_hello_req(s, pkt);
1073 
1074     case TLS_ST_CR_ENCRYPTED_EXTENSIONS:
1075         return tls_process_encrypted_extensions(s, pkt);
1076 
1077     case TLS_ST_CR_KEY_UPDATE:
1078         return tls_process_key_update(s, pkt);
1079     }
1080 }
1081 
1082 /*
1083  * Perform any further processing required following the receipt of a message
1084  * from the server
1085  */
1086 WORK_STATE ossl_statem_client_post_process_message(SSL *s, WORK_STATE wst)
1087 {
1088     OSSL_STATEM *st = &s->statem;
1089 
1090     switch (st->hand_state) {
1091     default:
1092         /* Shouldn't happen */
1093         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1094                  SSL_F_OSSL_STATEM_CLIENT_POST_PROCESS_MESSAGE,
1095                  ERR_R_INTERNAL_ERROR);
1096         return WORK_ERROR;
1097 
1098     case TLS_ST_CR_CERT_VRFY:
1099     case TLS_ST_CR_CERT_REQ:
1100         return tls_prepare_client_certificate(s, wst);
1101     }
1102 }
1103 
1104 int tls_construct_client_hello(SSL *s, WPACKET *pkt)
1105 {
1106     unsigned char *p;
1107     size_t sess_id_len;
1108     int i, protverr;
1109 #ifndef OPENSSL_NO_COMP
1110     SSL_COMP *comp;
1111 #endif
1112     SSL_SESSION *sess = s->session;
1113     unsigned char *session_id;
1114 
1115     /* Work out what SSL/TLS/DTLS version to use */
1116     protverr = ssl_set_client_hello_version(s);
1117     if (protverr != 0) {
1118         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1119                  protverr);
1120         return 0;
1121     }
1122 
1123     if (sess == NULL
1124             || !ssl_version_supported(s, sess->ssl_version, NULL)
1125             || !SSL_SESSION_is_resumable(sess)) {
1126         if (s->hello_retry_request == SSL_HRR_NONE
1127                 && !ssl_get_new_session(s, 0)) {
1128             /* SSLfatal() already called */
1129             return 0;
1130         }
1131     }
1132     /* else use the pre-loaded session */
1133 
1134     p = s->s3->client_random;
1135 
1136     /*
1137      * for DTLS if client_random is initialized, reuse it, we are
1138      * required to use same upon reply to HelloVerify
1139      */
1140     if (SSL_IS_DTLS(s)) {
1141         size_t idx;
1142         i = 1;
1143         for (idx = 0; idx < sizeof(s->s3->client_random); idx++) {
1144             if (p[idx]) {
1145                 i = 0;
1146                 break;
1147             }
1148         }
1149     } else {
1150         i = (s->hello_retry_request == SSL_HRR_NONE);
1151     }
1152 
1153     if (i && ssl_fill_hello_random(s, 0, p, sizeof(s->s3->client_random),
1154                                    DOWNGRADE_NONE) <= 0) {
1155         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1156                  ERR_R_INTERNAL_ERROR);
1157         return 0;
1158     }
1159 
1160     /*-
1161      * version indicates the negotiated version: for example from
1162      * an SSLv2/v3 compatible client hello). The client_version
1163      * field is the maximum version we permit and it is also
1164      * used in RSA encrypted premaster secrets. Some servers can
1165      * choke if we initially report a higher version then
1166      * renegotiate to a lower one in the premaster secret. This
1167      * didn't happen with TLS 1.0 as most servers supported it
1168      * but it can with TLS 1.1 or later if the server only supports
1169      * 1.0.
1170      *
1171      * Possible scenario with previous logic:
1172      *      1. Client hello indicates TLS 1.2
1173      *      2. Server hello says TLS 1.0
1174      *      3. RSA encrypted premaster secret uses 1.2.
1175      *      4. Handshake proceeds using TLS 1.0.
1176      *      5. Server sends hello request to renegotiate.
1177      *      6. Client hello indicates TLS v1.0 as we now
1178      *         know that is maximum server supports.
1179      *      7. Server chokes on RSA encrypted premaster secret
1180      *         containing version 1.0.
1181      *
1182      * For interoperability it should be OK to always use the
1183      * maximum version we support in client hello and then rely
1184      * on the checking of version to ensure the servers isn't
1185      * being inconsistent: for example initially negotiating with
1186      * TLS 1.0 and renegotiating with TLS 1.2. We do this by using
1187      * client_version in client hello and not resetting it to
1188      * the negotiated version.
1189      *
1190      * For TLS 1.3 we always set the ClientHello version to 1.2 and rely on the
1191      * supported_versions extension for the real supported versions.
1192      */
1193     if (!WPACKET_put_bytes_u16(pkt, s->client_version)
1194             || !WPACKET_memcpy(pkt, s->s3->client_random, SSL3_RANDOM_SIZE)) {
1195         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1196                  ERR_R_INTERNAL_ERROR);
1197         return 0;
1198     }
1199 
1200     /* Session ID */
1201     session_id = s->session->session_id;
1202     if (s->new_session || s->session->ssl_version == TLS1_3_VERSION) {
1203         if (s->version == TLS1_3_VERSION
1204                 && (s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0) {
1205             sess_id_len = sizeof(s->tmp_session_id);
1206             s->tmp_session_id_len = sess_id_len;
1207             session_id = s->tmp_session_id;
1208             if (s->hello_retry_request == SSL_HRR_NONE
1209                     && RAND_bytes(s->tmp_session_id, sess_id_len) <= 0) {
1210                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1211                          SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1212                          ERR_R_INTERNAL_ERROR);
1213                 return 0;
1214             }
1215         } else {
1216             sess_id_len = 0;
1217         }
1218     } else {
1219         assert(s->session->session_id_length <= sizeof(s->session->session_id));
1220         sess_id_len = s->session->session_id_length;
1221         if (s->version == TLS1_3_VERSION) {
1222             s->tmp_session_id_len = sess_id_len;
1223             memcpy(s->tmp_session_id, s->session->session_id, sess_id_len);
1224         }
1225     }
1226     if (!WPACKET_start_sub_packet_u8(pkt)
1227             || (sess_id_len != 0 && !WPACKET_memcpy(pkt, session_id,
1228                                                     sess_id_len))
1229             || !WPACKET_close(pkt)) {
1230         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1231                  ERR_R_INTERNAL_ERROR);
1232         return 0;
1233     }
1234 
1235     /* cookie stuff for DTLS */
1236     if (SSL_IS_DTLS(s)) {
1237         if (s->d1->cookie_len > sizeof(s->d1->cookie)
1238                 || !WPACKET_sub_memcpy_u8(pkt, s->d1->cookie,
1239                                           s->d1->cookie_len)) {
1240             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1241                      ERR_R_INTERNAL_ERROR);
1242             return 0;
1243         }
1244     }
1245 
1246     /* Ciphers supported */
1247     if (!WPACKET_start_sub_packet_u16(pkt)) {
1248         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1249                  ERR_R_INTERNAL_ERROR);
1250         return 0;
1251     }
1252 
1253     if (!ssl_cipher_list_to_bytes(s, SSL_get_ciphers(s), pkt)) {
1254         /* SSLfatal() already called */
1255         return 0;
1256     }
1257     if (!WPACKET_close(pkt)) {
1258         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1259                  ERR_R_INTERNAL_ERROR);
1260         return 0;
1261     }
1262 
1263     /* COMPRESSION */
1264     if (!WPACKET_start_sub_packet_u8(pkt)) {
1265         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1266                  ERR_R_INTERNAL_ERROR);
1267         return 0;
1268     }
1269 #ifndef OPENSSL_NO_COMP
1270     if (ssl_allow_compression(s)
1271             && s->ctx->comp_methods
1272             && (SSL_IS_DTLS(s) || s->s3->tmp.max_ver < TLS1_3_VERSION)) {
1273         int compnum = sk_SSL_COMP_num(s->ctx->comp_methods);
1274         for (i = 0; i < compnum; i++) {
1275             comp = sk_SSL_COMP_value(s->ctx->comp_methods, i);
1276             if (!WPACKET_put_bytes_u8(pkt, comp->id)) {
1277                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1278                          SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1279                          ERR_R_INTERNAL_ERROR);
1280                 return 0;
1281             }
1282         }
1283     }
1284 #endif
1285     /* Add the NULL method */
1286     if (!WPACKET_put_bytes_u8(pkt, 0) || !WPACKET_close(pkt)) {
1287         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CLIENT_HELLO,
1288                  ERR_R_INTERNAL_ERROR);
1289         return 0;
1290     }
1291 
1292     /* TLS extensions */
1293     if (!tls_construct_extensions(s, pkt, SSL_EXT_CLIENT_HELLO, NULL, 0)) {
1294         /* SSLfatal() already called */
1295         return 0;
1296     }
1297 
1298     return 1;
1299 }
1300 
1301 MSG_PROCESS_RETURN dtls_process_hello_verify(SSL *s, PACKET *pkt)
1302 {
1303     size_t cookie_len;
1304     PACKET cookiepkt;
1305 
1306     if (!PACKET_forward(pkt, 2)
1307         || !PACKET_get_length_prefixed_1(pkt, &cookiepkt)) {
1308         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
1309                  SSL_R_LENGTH_MISMATCH);
1310         return MSG_PROCESS_ERROR;
1311     }
1312 
1313     cookie_len = PACKET_remaining(&cookiepkt);
1314     if (cookie_len > sizeof(s->d1->cookie)) {
1315         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
1316                  SSL_R_LENGTH_TOO_LONG);
1317         return MSG_PROCESS_ERROR;
1318     }
1319 
1320     if (!PACKET_copy_bytes(&cookiepkt, s->d1->cookie, cookie_len)) {
1321         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_DTLS_PROCESS_HELLO_VERIFY,
1322                  SSL_R_LENGTH_MISMATCH);
1323         return MSG_PROCESS_ERROR;
1324     }
1325     s->d1->cookie_len = cookie_len;
1326 
1327     return MSG_PROCESS_FINISHED_READING;
1328 }
1329 
1330 static int set_client_ciphersuite(SSL *s, const unsigned char *cipherchars)
1331 {
1332     STACK_OF(SSL_CIPHER) *sk;
1333     const SSL_CIPHER *c;
1334     int i;
1335 
1336     c = ssl_get_cipher_by_char(s, cipherchars, 0);
1337     if (c == NULL) {
1338         /* unknown cipher */
1339         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1340                  SSL_R_UNKNOWN_CIPHER_RETURNED);
1341         return 0;
1342     }
1343     /*
1344      * If it is a disabled cipher we either didn't send it in client hello,
1345      * or it's not allowed for the selected protocol. So we return an error.
1346      */
1347     if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_CHECK, 1)) {
1348         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1349                  SSL_R_WRONG_CIPHER_RETURNED);
1350         return 0;
1351     }
1352 
1353     sk = ssl_get_ciphers_by_id(s);
1354     i = sk_SSL_CIPHER_find(sk, c);
1355     if (i < 0) {
1356         /* we did not say we would use this cipher */
1357         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1358                  SSL_R_WRONG_CIPHER_RETURNED);
1359         return 0;
1360     }
1361 
1362     if (SSL_IS_TLS13(s) && s->s3->tmp.new_cipher != NULL
1363             && s->s3->tmp.new_cipher->id != c->id) {
1364         /* ServerHello selected a different ciphersuite to that in the HRR */
1365         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1366                  SSL_R_WRONG_CIPHER_RETURNED);
1367         return 0;
1368     }
1369 
1370     /*
1371      * Depending on the session caching (internal/external), the cipher
1372      * and/or cipher_id values may not be set. Make sure that cipher_id is
1373      * set and use it for comparison.
1374      */
1375     if (s->session->cipher != NULL)
1376         s->session->cipher_id = s->session->cipher->id;
1377     if (s->hit && (s->session->cipher_id != c->id)) {
1378         if (SSL_IS_TLS13(s)) {
1379             /*
1380              * In TLSv1.3 it is valid for the server to select a different
1381              * ciphersuite as long as the hash is the same.
1382              */
1383             if (ssl_md(c->algorithm2)
1384                     != ssl_md(s->session->cipher->algorithm2)) {
1385                 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1386                          SSL_F_SET_CLIENT_CIPHERSUITE,
1387                          SSL_R_CIPHERSUITE_DIGEST_HAS_CHANGED);
1388                 return 0;
1389             }
1390         } else {
1391             /*
1392              * Prior to TLSv1.3 resuming a session always meant using the same
1393              * ciphersuite.
1394              */
1395             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SET_CLIENT_CIPHERSUITE,
1396                      SSL_R_OLD_SESSION_CIPHER_NOT_RETURNED);
1397             return 0;
1398         }
1399     }
1400     s->s3->tmp.new_cipher = c;
1401 
1402     return 1;
1403 }
1404 
1405 MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
1406 {
1407     PACKET session_id, extpkt;
1408     size_t session_id_len;
1409     const unsigned char *cipherchars;
1410     int hrr = 0;
1411     unsigned int compression;
1412     unsigned int sversion;
1413     unsigned int context;
1414     RAW_EXTENSION *extensions = NULL;
1415 #ifndef OPENSSL_NO_COMP
1416     SSL_COMP *comp;
1417 #endif
1418 
1419     if (!PACKET_get_net_2(pkt, &sversion)) {
1420         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1421                  SSL_R_LENGTH_MISMATCH);
1422         goto err;
1423     }
1424 
1425     /* load the server random */
1426     if (s->version == TLS1_3_VERSION
1427             && sversion == TLS1_2_VERSION
1428             && PACKET_remaining(pkt) >= SSL3_RANDOM_SIZE
1429             && memcmp(hrrrandom, PACKET_data(pkt), SSL3_RANDOM_SIZE) == 0) {
1430         s->hello_retry_request = SSL_HRR_PENDING;
1431         hrr = 1;
1432         if (!PACKET_forward(pkt, SSL3_RANDOM_SIZE)) {
1433             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1434                      SSL_R_LENGTH_MISMATCH);
1435             goto err;
1436         }
1437     } else {
1438         if (!PACKET_copy_bytes(pkt, s->s3->server_random, SSL3_RANDOM_SIZE)) {
1439             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1440                      SSL_R_LENGTH_MISMATCH);
1441             goto err;
1442         }
1443     }
1444 
1445     /* Get the session-id. */
1446     if (!PACKET_get_length_prefixed_1(pkt, &session_id)) {
1447         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1448                  SSL_R_LENGTH_MISMATCH);
1449         goto err;
1450     }
1451     session_id_len = PACKET_remaining(&session_id);
1452     if (session_id_len > sizeof(s->session->session_id)
1453         || session_id_len > SSL3_SESSION_ID_SIZE) {
1454         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1455                  SSL_R_SSL3_SESSION_ID_TOO_LONG);
1456         goto err;
1457     }
1458 
1459     if (!PACKET_get_bytes(pkt, &cipherchars, TLS_CIPHER_LEN)) {
1460         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1461                  SSL_R_LENGTH_MISMATCH);
1462         goto err;
1463     }
1464 
1465     if (!PACKET_get_1(pkt, &compression)) {
1466         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1467                  SSL_R_LENGTH_MISMATCH);
1468         goto err;
1469     }
1470 
1471     /* TLS extensions */
1472     if (PACKET_remaining(pkt) == 0 && !hrr) {
1473         PACKET_null_init(&extpkt);
1474     } else if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
1475                || PACKET_remaining(pkt) != 0) {
1476         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1477                  SSL_R_BAD_LENGTH);
1478         goto err;
1479     }
1480 
1481     if (!hrr) {
1482         if (!tls_collect_extensions(s, &extpkt,
1483                                     SSL_EXT_TLS1_2_SERVER_HELLO
1484                                     | SSL_EXT_TLS1_3_SERVER_HELLO,
1485                                     &extensions, NULL, 1)) {
1486             /* SSLfatal() already called */
1487             goto err;
1488         }
1489 
1490         if (!ssl_choose_client_version(s, sversion, extensions)) {
1491             /* SSLfatal() already called */
1492             goto err;
1493         }
1494     }
1495 
1496     if (SSL_IS_TLS13(s) || hrr) {
1497         if (compression != 0) {
1498             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1499                      SSL_F_TLS_PROCESS_SERVER_HELLO,
1500                      SSL_R_INVALID_COMPRESSION_ALGORITHM);
1501             goto err;
1502         }
1503 
1504         if (session_id_len != s->tmp_session_id_len
1505                 || memcmp(PACKET_data(&session_id), s->tmp_session_id,
1506                           session_id_len) != 0) {
1507             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1508                      SSL_F_TLS_PROCESS_SERVER_HELLO, SSL_R_INVALID_SESSION_ID);
1509             goto err;
1510         }
1511     }
1512 
1513     if (hrr) {
1514         if (!set_client_ciphersuite(s, cipherchars)) {
1515             /* SSLfatal() already called */
1516             goto err;
1517         }
1518 
1519         return tls_process_as_hello_retry_request(s, &extpkt);
1520     }
1521 
1522     /*
1523      * Now we have chosen the version we need to check again that the extensions
1524      * are appropriate for this version.
1525      */
1526     context = SSL_IS_TLS13(s) ? SSL_EXT_TLS1_3_SERVER_HELLO
1527                               : SSL_EXT_TLS1_2_SERVER_HELLO;
1528     if (!tls_validate_all_contexts(s, context, extensions)) {
1529         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1530                  SSL_R_BAD_EXTENSION);
1531         goto err;
1532     }
1533 
1534     s->hit = 0;
1535 
1536     if (SSL_IS_TLS13(s)) {
1537         /*
1538          * In TLSv1.3 a ServerHello message signals a key change so the end of
1539          * the message must be on a record boundary.
1540          */
1541         if (RECORD_LAYER_processed_read_pending(&s->rlayer)) {
1542             SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
1543                      SSL_F_TLS_PROCESS_SERVER_HELLO,
1544                      SSL_R_NOT_ON_RECORD_BOUNDARY);
1545             goto err;
1546         }
1547 
1548         /* This will set s->hit if we are resuming */
1549         if (!tls_parse_extension(s, TLSEXT_IDX_psk,
1550                                  SSL_EXT_TLS1_3_SERVER_HELLO,
1551                                  extensions, NULL, 0)) {
1552             /* SSLfatal() already called */
1553             goto err;
1554         }
1555     } else {
1556         /*
1557          * Check if we can resume the session based on external pre-shared
1558          * secret. EAP-FAST (RFC 4851) supports two types of session resumption.
1559          * Resumption based on server-side state works with session IDs.
1560          * Resumption based on pre-shared Protected Access Credentials (PACs)
1561          * works by overriding the SessionTicket extension at the application
1562          * layer, and does not send a session ID. (We do not know whether
1563          * EAP-FAST servers would honour the session ID.) Therefore, the session
1564          * ID alone is not a reliable indicator of session resumption, so we
1565          * first check if we can resume, and later peek at the next handshake
1566          * message to see if the server wants to resume.
1567          */
1568         if (s->version >= TLS1_VERSION
1569                 && s->ext.session_secret_cb != NULL && s->session->ext.tick) {
1570             const SSL_CIPHER *pref_cipher = NULL;
1571             /*
1572              * s->session->master_key_length is a size_t, but this is an int for
1573              * backwards compat reasons
1574              */
1575             int master_key_length;
1576             master_key_length = sizeof(s->session->master_key);
1577             if (s->ext.session_secret_cb(s, s->session->master_key,
1578                                          &master_key_length,
1579                                          NULL, &pref_cipher,
1580                                          s->ext.session_secret_cb_arg)
1581                      && master_key_length > 0) {
1582                 s->session->master_key_length = master_key_length;
1583                 s->session->cipher = pref_cipher ?
1584                     pref_cipher : ssl_get_cipher_by_char(s, cipherchars, 0);
1585             } else {
1586                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1587                          SSL_F_TLS_PROCESS_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
1588                 goto err;
1589             }
1590         }
1591 
1592         if (session_id_len != 0
1593                 && session_id_len == s->session->session_id_length
1594                 && memcmp(PACKET_data(&session_id), s->session->session_id,
1595                           session_id_len) == 0)
1596             s->hit = 1;
1597     }
1598 
1599     if (s->hit) {
1600         if (s->sid_ctx_length != s->session->sid_ctx_length
1601                 || memcmp(s->session->sid_ctx, s->sid_ctx, s->sid_ctx_length)) {
1602             /* actually a client application bug */
1603             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1604                      SSL_F_TLS_PROCESS_SERVER_HELLO,
1605                      SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT);
1606             goto err;
1607         }
1608     } else {
1609         /*
1610          * If we were trying for session-id reuse but the server
1611          * didn't resume, make a new SSL_SESSION.
1612          * In the case of EAP-FAST and PAC, we do not send a session ID,
1613          * so the PAC-based session secret is always preserved. It'll be
1614          * overwritten if the server refuses resumption.
1615          */
1616         if (s->session->session_id_length > 0) {
1617             tsan_counter(&s->session_ctx->stats.sess_miss);
1618             if (!ssl_get_new_session(s, 0)) {
1619                 /* SSLfatal() already called */
1620                 goto err;
1621             }
1622         }
1623 
1624         s->session->ssl_version = s->version;
1625         /*
1626          * In TLSv1.2 and below we save the session id we were sent so we can
1627          * resume it later. In TLSv1.3 the session id we were sent is just an
1628          * echo of what we originally sent in the ClientHello and should not be
1629          * used for resumption.
1630          */
1631         if (!SSL_IS_TLS13(s)) {
1632             s->session->session_id_length = session_id_len;
1633             /* session_id_len could be 0 */
1634             if (session_id_len > 0)
1635                 memcpy(s->session->session_id, PACKET_data(&session_id),
1636                        session_id_len);
1637         }
1638     }
1639 
1640     /* Session version and negotiated protocol version should match */
1641     if (s->version != s->session->ssl_version) {
1642         SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_TLS_PROCESS_SERVER_HELLO,
1643                  SSL_R_SSL_SESSION_VERSION_MISMATCH);
1644         goto err;
1645     }
1646     /*
1647      * Now that we know the version, update the check to see if it's an allowed
1648      * version.
1649      */
1650     s->s3->tmp.min_ver = s->version;
1651     s->s3->tmp.max_ver = s->version;
1652 
1653     if (!set_client_ciphersuite(s, cipherchars)) {
1654         /* SSLfatal() already called */
1655         goto err;
1656     }
1657 
1658 #ifdef OPENSSL_NO_COMP
1659     if (compression != 0) {
1660         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1661                  SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
1662         goto err;
1663     }
1664     /*
1665      * If compression is disabled we'd better not try to resume a session
1666      * using compression.
1667      */
1668     if (s->session->compress_meth != 0) {
1669         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SERVER_HELLO,
1670                  SSL_R_INCONSISTENT_COMPRESSION);
1671         goto err;
1672     }
1673 #else
1674     if (s->hit && compression != s->session->compress_meth) {
1675         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1676                  SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
1677         goto err;
1678     }
1679     if (compression == 0)
1680         comp = NULL;
1681     else if (!ssl_allow_compression(s)) {
1682         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1683                  SSL_R_COMPRESSION_DISABLED);
1684         goto err;
1685     } else {
1686         comp = ssl3_comp_find(s->ctx->comp_methods, compression);
1687     }
1688 
1689     if (compression != 0 && comp == NULL) {
1690         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1691                  SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
1692         goto err;
1693     } else {
1694         s->s3->tmp.new_compression = comp;
1695     }
1696 #endif
1697 
1698     if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, 1)) {
1699         /* SSLfatal() already called */
1700         goto err;
1701     }
1702 
1703 #ifndef OPENSSL_NO_SCTP
1704     if (SSL_IS_DTLS(s) && s->hit) {
1705         unsigned char sctpauthkey[64];
1706         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
1707         size_t labellen;
1708 
1709         /*
1710          * Add new shared key for SCTP-Auth, will be ignored if
1711          * no SCTP used.
1712          */
1713         memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
1714                sizeof(DTLS1_SCTP_AUTH_LABEL));
1715 
1716         /* Don't include the terminating zero. */
1717         labellen = sizeof(labelbuffer) - 1;
1718         if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
1719             labellen += 1;
1720 
1721         if (SSL_export_keying_material(s, sctpauthkey,
1722                                        sizeof(sctpauthkey),
1723                                        labelbuffer,
1724                                        labellen, NULL, 0, 0) <= 0) {
1725             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1726                      ERR_R_INTERNAL_ERROR);
1727             goto err;
1728         }
1729 
1730         BIO_ctrl(SSL_get_wbio(s),
1731                  BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
1732                  sizeof(sctpauthkey), sctpauthkey);
1733     }
1734 #endif
1735 
1736     /*
1737      * In TLSv1.3 we have some post-processing to change cipher state, otherwise
1738      * we're done with this message
1739      */
1740     if (SSL_IS_TLS13(s)
1741             && (!s->method->ssl3_enc->setup_key_block(s)
1742                 || !s->method->ssl3_enc->change_cipher_state(s,
1743                     SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_READ))) {
1744         /* SSLfatal() already called */
1745         goto err;
1746     }
1747 
1748     OPENSSL_free(extensions);
1749     return MSG_PROCESS_CONTINUE_READING;
1750  err:
1751     OPENSSL_free(extensions);
1752     return MSG_PROCESS_ERROR;
1753 }
1754 
1755 static MSG_PROCESS_RETURN tls_process_as_hello_retry_request(SSL *s,
1756                                                              PACKET *extpkt)
1757 {
1758     RAW_EXTENSION *extensions = NULL;
1759 
1760     /*
1761      * If we were sending early_data then the enc_write_ctx is now invalid and
1762      * should not be used.
1763      */
1764     EVP_CIPHER_CTX_free(s->enc_write_ctx);
1765     s->enc_write_ctx = NULL;
1766 
1767     if (!tls_collect_extensions(s, extpkt, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
1768                                 &extensions, NULL, 1)
1769             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
1770                                          extensions, NULL, 0, 1)) {
1771         /* SSLfatal() already called */
1772         goto err;
1773     }
1774 
1775     OPENSSL_free(extensions);
1776     extensions = NULL;
1777 
1778     if (s->ext.tls13_cookie_len == 0
1779 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
1780         && s->s3->tmp.pkey != NULL
1781 #endif
1782         ) {
1783         /*
1784          * We didn't receive a cookie or a new key_share so the next
1785          * ClientHello will not change
1786          */
1787         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1788                  SSL_F_TLS_PROCESS_AS_HELLO_RETRY_REQUEST,
1789                  SSL_R_NO_CHANGE_FOLLOWING_HRR);
1790         goto err;
1791     }
1792 
1793     /*
1794      * Re-initialise the Transcript Hash. We're going to prepopulate it with
1795      * a synthetic message_hash in place of ClientHello1.
1796      */
1797     if (!create_synthetic_message_hash(s, NULL, 0, NULL, 0)) {
1798         /* SSLfatal() already called */
1799         goto err;
1800     }
1801 
1802     /*
1803      * Add this message to the Transcript Hash. Normally this is done
1804      * automatically prior to the message processing stage. However due to the
1805      * need to create the synthetic message hash, we defer that step until now
1806      * for HRR messages.
1807      */
1808     if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
1809                                 s->init_num + SSL3_HM_HEADER_LENGTH)) {
1810         /* SSLfatal() already called */
1811         goto err;
1812     }
1813 
1814     return MSG_PROCESS_FINISHED_READING;
1815  err:
1816     OPENSSL_free(extensions);
1817     return MSG_PROCESS_ERROR;
1818 }
1819 
1820 MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
1821 {
1822     int i;
1823     MSG_PROCESS_RETURN ret = MSG_PROCESS_ERROR;
1824     unsigned long cert_list_len, cert_len;
1825     X509 *x = NULL;
1826     const unsigned char *certstart, *certbytes;
1827     STACK_OF(X509) *sk = NULL;
1828     EVP_PKEY *pkey = NULL;
1829     size_t chainidx, certidx;
1830     unsigned int context = 0;
1831     const SSL_CERT_LOOKUP *clu;
1832 
1833     if ((sk = sk_X509_new_null()) == NULL) {
1834         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1835                  ERR_R_MALLOC_FAILURE);
1836         goto err;
1837     }
1838 
1839     if ((SSL_IS_TLS13(s) && !PACKET_get_1(pkt, &context))
1840             || context != 0
1841             || !PACKET_get_net_3(pkt, &cert_list_len)
1842             || PACKET_remaining(pkt) != cert_list_len
1843             || PACKET_remaining(pkt) == 0) {
1844         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1845                  SSL_R_LENGTH_MISMATCH);
1846         goto err;
1847     }
1848     for (chainidx = 0; PACKET_remaining(pkt); chainidx++) {
1849         if (!PACKET_get_net_3(pkt, &cert_len)
1850             || !PACKET_get_bytes(pkt, &certbytes, cert_len)) {
1851             SSLfatal(s, SSL_AD_DECODE_ERROR,
1852                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1853                      SSL_R_CERT_LENGTH_MISMATCH);
1854             goto err;
1855         }
1856 
1857         certstart = certbytes;
1858         x = d2i_X509(NULL, (const unsigned char **)&certbytes, cert_len);
1859         if (x == NULL) {
1860             SSLfatal(s, SSL_AD_BAD_CERTIFICATE,
1861                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_ASN1_LIB);
1862             goto err;
1863         }
1864         if (certbytes != (certstart + cert_len)) {
1865             SSLfatal(s, SSL_AD_DECODE_ERROR,
1866                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1867                      SSL_R_CERT_LENGTH_MISMATCH);
1868             goto err;
1869         }
1870 
1871         if (SSL_IS_TLS13(s)) {
1872             RAW_EXTENSION *rawexts = NULL;
1873             PACKET extensions;
1874 
1875             if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
1876                 SSLfatal(s, SSL_AD_DECODE_ERROR,
1877                          SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1878                          SSL_R_BAD_LENGTH);
1879                 goto err;
1880             }
1881             if (!tls_collect_extensions(s, &extensions,
1882                                         SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
1883                                         NULL, chainidx == 0)
1884                 || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
1885                                              rawexts, x, chainidx,
1886                                              PACKET_remaining(pkt) == 0)) {
1887                 OPENSSL_free(rawexts);
1888                 /* SSLfatal already called */
1889                 goto err;
1890             }
1891             OPENSSL_free(rawexts);
1892         }
1893 
1894         if (!sk_X509_push(sk, x)) {
1895             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1896                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1897                      ERR_R_MALLOC_FAILURE);
1898             goto err;
1899         }
1900         x = NULL;
1901     }
1902 
1903     i = ssl_verify_cert_chain(s, sk);
1904     /*
1905      * The documented interface is that SSL_VERIFY_PEER should be set in order
1906      * for client side verification of the server certificate to take place.
1907      * However, historically the code has only checked that *any* flag is set
1908      * to cause server verification to take place. Use of the other flags makes
1909      * no sense in client mode. An attempt to clean up the semantics was
1910      * reverted because at least one application *only* set
1911      * SSL_VERIFY_FAIL_IF_NO_PEER_CERT. Prior to the clean up this still caused
1912      * server verification to take place, after the clean up it silently did
1913      * nothing. SSL_CTX_set_verify()/SSL_set_verify() cannot validate the flags
1914      * sent to them because they are void functions. Therefore, we now use the
1915      * (less clean) historic behaviour of performing validation if any flag is
1916      * set. The *documented* interface remains the same.
1917      */
1918     if (s->verify_mode != SSL_VERIFY_NONE && i <= 0) {
1919         SSLfatal(s, ssl_x509err2alert(s->verify_result),
1920                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1921                  SSL_R_CERTIFICATE_VERIFY_FAILED);
1922         goto err;
1923     }
1924     ERR_clear_error();          /* but we keep s->verify_result */
1925     if (i > 1) {
1926         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
1927                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, i);
1928         goto err;
1929     }
1930 
1931     s->session->peer_chain = sk;
1932     /*
1933      * Inconsistency alert: cert_chain does include the peer's certificate,
1934      * which we don't include in statem_srvr.c
1935      */
1936     x = sk_X509_value(sk, 0);
1937     sk = NULL;
1938 
1939     pkey = X509_get0_pubkey(x);
1940 
1941     if (pkey == NULL || EVP_PKEY_missing_parameters(pkey)) {
1942         x = NULL;
1943         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1944                  SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS);
1945         goto err;
1946     }
1947 
1948     if ((clu = ssl_cert_lookup_by_pkey(pkey, &certidx)) == NULL) {
1949         x = NULL;
1950         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1951                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1952                  SSL_R_UNKNOWN_CERTIFICATE_TYPE);
1953         goto err;
1954     }
1955     /*
1956      * Check certificate type is consistent with ciphersuite. For TLS 1.3
1957      * skip check since TLS 1.3 ciphersuites can be used with any certificate
1958      * type.
1959      */
1960     if (!SSL_IS_TLS13(s)) {
1961         if ((clu->amask & s->s3->tmp.new_cipher->algorithm_auth) == 0) {
1962             x = NULL;
1963             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1964                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1965                      SSL_R_WRONG_CERTIFICATE_TYPE);
1966             goto err;
1967         }
1968     }
1969     s->session->peer_type = certidx;
1970 
1971     X509_free(s->session->peer);
1972     X509_up_ref(x);
1973     s->session->peer = x;
1974     s->session->verify_result = s->verify_result;
1975     x = NULL;
1976 
1977     /* Save the current hash state for when we receive the CertificateVerify */
1978     if (SSL_IS_TLS13(s)
1979             && !ssl_handshake_hash(s, s->cert_verify_hash,
1980                                    sizeof(s->cert_verify_hash),
1981                                    &s->cert_verify_hash_len)) {
1982         /* SSLfatal() already called */;
1983         goto err;
1984     }
1985 
1986     ret = MSG_PROCESS_CONTINUE_READING;
1987 
1988  err:
1989     X509_free(x);
1990     sk_X509_pop_free(sk, X509_free);
1991     return ret;
1992 }
1993 
1994 static int tls_process_ske_psk_preamble(SSL *s, PACKET *pkt)
1995 {
1996 #ifndef OPENSSL_NO_PSK
1997     PACKET psk_identity_hint;
1998 
1999     /* PSK ciphersuites are preceded by an identity hint */
2000 
2001     if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {
2002         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2003                  SSL_R_LENGTH_MISMATCH);
2004         return 0;
2005     }
2006 
2007     /*
2008      * Store PSK identity hint for later use, hint is used in
2009      * tls_construct_client_key_exchange.  Assume that the maximum length of
2010      * a PSK identity hint can be as long as the maximum length of a PSK
2011      * identity.
2012      */
2013     if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {
2014         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2015                  SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2016                  SSL_R_DATA_LENGTH_TOO_LONG);
2017         return 0;
2018     }
2019 
2020     if (PACKET_remaining(&psk_identity_hint) == 0) {
2021         OPENSSL_free(s->session->psk_identity_hint);
2022         s->session->psk_identity_hint = NULL;
2023     } else if (!PACKET_strndup(&psk_identity_hint,
2024                                &s->session->psk_identity_hint)) {
2025         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2026                  ERR_R_INTERNAL_ERROR);
2027         return 0;
2028     }
2029 
2030     return 1;
2031 #else
2032     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2033              ERR_R_INTERNAL_ERROR);
2034     return 0;
2035 #endif
2036 }
2037 
2038 static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2039 {
2040 #ifndef OPENSSL_NO_SRP
2041     PACKET prime, generator, salt, server_pub;
2042 
2043     if (!PACKET_get_length_prefixed_2(pkt, &prime)
2044         || !PACKET_get_length_prefixed_2(pkt, &generator)
2045         || !PACKET_get_length_prefixed_1(pkt, &salt)
2046         || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
2047         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2048                  SSL_R_LENGTH_MISMATCH);
2049         return 0;
2050     }
2051 
2052     /* TODO(size_t): Convert BN_bin2bn() calls */
2053     if ((s->srp_ctx.N =
2054          BN_bin2bn(PACKET_data(&prime),
2055                    (int)PACKET_remaining(&prime), NULL)) == NULL
2056         || (s->srp_ctx.g =
2057             BN_bin2bn(PACKET_data(&generator),
2058                       (int)PACKET_remaining(&generator), NULL)) == NULL
2059         || (s->srp_ctx.s =
2060             BN_bin2bn(PACKET_data(&salt),
2061                       (int)PACKET_remaining(&salt), NULL)) == NULL
2062         || (s->srp_ctx.B =
2063             BN_bin2bn(PACKET_data(&server_pub),
2064                       (int)PACKET_remaining(&server_pub), NULL)) == NULL) {
2065         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2066                  ERR_R_BN_LIB);
2067         return 0;
2068     }
2069 
2070     if (!srp_verify_server_param(s)) {
2071         /* SSLfatal() already called */
2072         return 0;
2073     }
2074 
2075     /* We must check if there is a certificate */
2076     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
2077         *pkey = X509_get0_pubkey(s->session->peer);
2078 
2079     return 1;
2080 #else
2081     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2082              ERR_R_INTERNAL_ERROR);
2083     return 0;
2084 #endif
2085 }
2086 
2087 static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2088 {
2089 #ifndef OPENSSL_NO_DH
2090     PACKET prime, generator, pub_key;
2091     EVP_PKEY *peer_tmp = NULL;
2092 
2093     DH *dh = NULL;
2094     BIGNUM *p = NULL, *g = NULL, *bnpub_key = NULL;
2095 
2096     int check_bits = 0;
2097 
2098     if (!PACKET_get_length_prefixed_2(pkt, &prime)
2099         || !PACKET_get_length_prefixed_2(pkt, &generator)
2100         || !PACKET_get_length_prefixed_2(pkt, &pub_key)) {
2101         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2102                  SSL_R_LENGTH_MISMATCH);
2103         return 0;
2104     }
2105 
2106     peer_tmp = EVP_PKEY_new();
2107     dh = DH_new();
2108 
2109     if (peer_tmp == NULL || dh == NULL) {
2110         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2111                  ERR_R_MALLOC_FAILURE);
2112         goto err;
2113     }
2114 
2115     /* TODO(size_t): Convert these calls */
2116     p = BN_bin2bn(PACKET_data(&prime), (int)PACKET_remaining(&prime), NULL);
2117     g = BN_bin2bn(PACKET_data(&generator), (int)PACKET_remaining(&generator),
2118                   NULL);
2119     bnpub_key = BN_bin2bn(PACKET_data(&pub_key),
2120                           (int)PACKET_remaining(&pub_key), NULL);
2121     if (p == NULL || g == NULL || bnpub_key == NULL) {
2122         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2123                  ERR_R_BN_LIB);
2124         goto err;
2125     }
2126 
2127     /* test non-zero pubkey */
2128     if (BN_is_zero(bnpub_key)) {
2129         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
2130                  SSL_R_BAD_DH_VALUE);
2131         goto err;
2132     }
2133 
2134     if (!DH_set0_pqg(dh, p, NULL, g)) {
2135         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2136                  ERR_R_BN_LIB);
2137         goto err;
2138     }
2139     p = g = NULL;
2140 
2141     if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
2142         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
2143                  SSL_R_BAD_DH_VALUE);
2144         goto err;
2145     }
2146 
2147     if (!DH_set0_key(dh, bnpub_key, NULL)) {
2148         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2149                  ERR_R_BN_LIB);
2150         goto err;
2151     }
2152     bnpub_key = NULL;
2153 
2154     if (!ssl_security(s, SSL_SECOP_TMP_DH, DH_security_bits(dh), 0, dh)) {
2155         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SKE_DHE,
2156                  SSL_R_DH_KEY_TOO_SMALL);
2157         goto err;
2158     }
2159 
2160     if (EVP_PKEY_assign_DH(peer_tmp, dh) == 0) {
2161         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2162                  ERR_R_EVP_LIB);
2163         goto err;
2164     }
2165 
2166     s->s3->peer_tmp = peer_tmp;
2167 
2168     /*
2169      * FIXME: This makes assumptions about which ciphersuites come with
2170      * public keys. We should have a less ad-hoc way of doing this
2171      */
2172     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
2173         *pkey = X509_get0_pubkey(s->session->peer);
2174     /* else anonymous DH, so no certificate or pkey. */
2175 
2176     return 1;
2177 
2178  err:
2179     BN_free(p);
2180     BN_free(g);
2181     BN_free(bnpub_key);
2182     DH_free(dh);
2183     EVP_PKEY_free(peer_tmp);
2184 
2185     return 0;
2186 #else
2187     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2188              ERR_R_INTERNAL_ERROR);
2189     return 0;
2190 #endif
2191 }
2192 
2193 static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2194 {
2195 #ifndef OPENSSL_NO_EC
2196     PACKET encoded_pt;
2197     unsigned int curve_type, curve_id;
2198 
2199     /*
2200      * Extract elliptic curve parameters and the server's ephemeral ECDH
2201      * public key. We only support named (not generic) curves and
2202      * ECParameters in this case is just three bytes.
2203      */
2204     if (!PACKET_get_1(pkt, &curve_type) || !PACKET_get_net_2(pkt, &curve_id)) {
2205         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2206                  SSL_R_LENGTH_TOO_SHORT);
2207         return 0;
2208     }
2209     /*
2210      * Check curve is named curve type and one of our preferences, if not
2211      * server has sent an invalid curve.
2212      */
2213     if (curve_type != NAMED_CURVE_TYPE
2214             || !tls1_check_group_id(s, curve_id, 1)) {
2215         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
2216                  SSL_R_WRONG_CURVE);
2217         return 0;
2218     }
2219 
2220     if ((s->s3->peer_tmp = ssl_generate_param_group(curve_id)) == NULL) {
2221         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2222                  SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
2223         return 0;
2224     }
2225 
2226     if (!PACKET_get_length_prefixed_1(pkt, &encoded_pt)) {
2227         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2228                  SSL_R_LENGTH_MISMATCH);
2229         return 0;
2230     }
2231 
2232     if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
2233                                         PACKET_data(&encoded_pt),
2234                                         PACKET_remaining(&encoded_pt))) {
2235         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
2236                  SSL_R_BAD_ECPOINT);
2237         return 0;
2238     }
2239 
2240     /*
2241      * The ECC/TLS specification does not mention the use of DSA to sign
2242      * ECParameters in the server key exchange message. We do support RSA
2243      * and ECDSA.
2244      */
2245     if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aECDSA)
2246         *pkey = X509_get0_pubkey(s->session->peer);
2247     else if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aRSA)
2248         *pkey = X509_get0_pubkey(s->session->peer);
2249     /* else anonymous ECDH, so no certificate or pkey. */
2250 
2251     return 1;
2252 #else
2253     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2254              ERR_R_INTERNAL_ERROR);
2255     return 0;
2256 #endif
2257 }
2258 
2259 MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
2260 {
2261     long alg_k;
2262     EVP_PKEY *pkey = NULL;
2263     EVP_MD_CTX *md_ctx = NULL;
2264     EVP_PKEY_CTX *pctx = NULL;
2265     PACKET save_param_start, signature;
2266 
2267     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
2268 
2269     save_param_start = *pkt;
2270 
2271 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
2272     EVP_PKEY_free(s->s3->peer_tmp);
2273     s->s3->peer_tmp = NULL;
2274 #endif
2275 
2276     if (alg_k & SSL_PSK) {
2277         if (!tls_process_ske_psk_preamble(s, pkt)) {
2278             /* SSLfatal() already called */
2279             goto err;
2280         }
2281     }
2282 
2283     /* Nothing else to do for plain PSK or RSAPSK */
2284     if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
2285     } else if (alg_k & SSL_kSRP) {
2286         if (!tls_process_ske_srp(s, pkt, &pkey)) {
2287             /* SSLfatal() already called */
2288             goto err;
2289         }
2290     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
2291         if (!tls_process_ske_dhe(s, pkt, &pkey)) {
2292             /* SSLfatal() already called */
2293             goto err;
2294         }
2295     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
2296         if (!tls_process_ske_ecdhe(s, pkt, &pkey)) {
2297             /* SSLfatal() already called */
2298             goto err;
2299         }
2300     } else if (alg_k) {
2301         SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2302                  SSL_R_UNEXPECTED_MESSAGE);
2303         goto err;
2304     }
2305 
2306     /* if it was signed, check the signature */
2307     if (pkey != NULL) {
2308         PACKET params;
2309         int maxsig;
2310         const EVP_MD *md = NULL;
2311         unsigned char *tbs;
2312         size_t tbslen;
2313         int rv;
2314 
2315         /*
2316          * |pkt| now points to the beginning of the signature, so the difference
2317          * equals the length of the parameters.
2318          */
2319         if (!PACKET_get_sub_packet(&save_param_start, &params,
2320                                    PACKET_remaining(&save_param_start) -
2321                                    PACKET_remaining(pkt))) {
2322             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2323                      ERR_R_INTERNAL_ERROR);
2324             goto err;
2325         }
2326 
2327         if (SSL_USE_SIGALGS(s)) {
2328             unsigned int sigalg;
2329 
2330             if (!PACKET_get_net_2(pkt, &sigalg)) {
2331                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2332                          SSL_R_LENGTH_TOO_SHORT);
2333                 goto err;
2334             }
2335             if (tls12_check_peer_sigalg(s, sigalg, pkey) <=0) {
2336                 /* SSLfatal() already called */
2337                 goto err;
2338             }
2339         } else if (!tls1_set_peer_legacy_sigalg(s, pkey)) {
2340             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2341                      ERR_R_INTERNAL_ERROR);
2342             goto err;
2343         }
2344 
2345         if (!tls1_lookup_md(s->s3->tmp.peer_sigalg, &md)) {
2346             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2347                      ERR_R_INTERNAL_ERROR);
2348             goto err;
2349         }
2350 #ifdef SSL_DEBUG
2351         if (SSL_USE_SIGALGS(s))
2352             fprintf(stderr, "USING TLSv1.2 HASH %s\n",
2353                     md == NULL ? "n/a" : EVP_MD_name(md));
2354 #endif
2355 
2356         if (!PACKET_get_length_prefixed_2(pkt, &signature)
2357             || PACKET_remaining(pkt) != 0) {
2358             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2359                      SSL_R_LENGTH_MISMATCH);
2360             goto err;
2361         }
2362         maxsig = EVP_PKEY_size(pkey);
2363         if (maxsig < 0) {
2364             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2365                      ERR_R_INTERNAL_ERROR);
2366             goto err;
2367         }
2368 
2369         /*
2370          * Check signature length
2371          */
2372         if (PACKET_remaining(&signature) > (size_t)maxsig) {
2373             /* wrong packet length */
2374             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2375                    SSL_R_WRONG_SIGNATURE_LENGTH);
2376             goto err;
2377         }
2378 
2379         md_ctx = EVP_MD_CTX_new();
2380         if (md_ctx == NULL) {
2381             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2382                      ERR_R_MALLOC_FAILURE);
2383             goto err;
2384         }
2385 
2386         if (EVP_DigestVerifyInit(md_ctx, &pctx, md, NULL, pkey) <= 0) {
2387             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2388                      ERR_R_EVP_LIB);
2389             goto err;
2390         }
2391         if (SSL_USE_PSS(s)) {
2392             if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
2393                 || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx,
2394                                                 RSA_PSS_SALTLEN_DIGEST) <= 0) {
2395                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2396                          SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
2397                 goto err;
2398             }
2399         }
2400         tbslen = construct_key_exchange_tbs(s, &tbs, PACKET_data(&params),
2401                                             PACKET_remaining(&params));
2402         if (tbslen == 0) {
2403             /* SSLfatal() already called */
2404             goto err;
2405         }
2406 
2407         rv = EVP_DigestVerify(md_ctx, PACKET_data(&signature),
2408                               PACKET_remaining(&signature), tbs, tbslen);
2409         OPENSSL_free(tbs);
2410         if (rv <= 0) {
2411             SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2412                      SSL_R_BAD_SIGNATURE);
2413             goto err;
2414         }
2415         EVP_MD_CTX_free(md_ctx);
2416         md_ctx = NULL;
2417     } else {
2418         /* aNULL, aSRP or PSK do not need public keys */
2419         if (!(s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aSRP))
2420             && !(alg_k & SSL_PSK)) {
2421             /* Might be wrong key type, check it */
2422             if (ssl3_check_cert_and_algorithm(s)) {
2423                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2424                          SSL_R_BAD_DATA);
2425             }
2426             /* else this shouldn't happen, SSLfatal() already called */
2427             goto err;
2428         }
2429         /* still data left over */
2430         if (PACKET_remaining(pkt) != 0) {
2431             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2432                      SSL_R_EXTRA_DATA_IN_MESSAGE);
2433             goto err;
2434         }
2435     }
2436 
2437     return MSG_PROCESS_CONTINUE_READING;
2438  err:
2439     EVP_MD_CTX_free(md_ctx);
2440     return MSG_PROCESS_ERROR;
2441 }
2442 
2443 MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
2444 {
2445     size_t i;
2446 
2447     /* Clear certificate validity flags */
2448     for (i = 0; i < SSL_PKEY_NUM; i++)
2449         s->s3->tmp.valid_flags[i] = 0;
2450 
2451     if (SSL_IS_TLS13(s)) {
2452         PACKET reqctx, extensions;
2453         RAW_EXTENSION *rawexts = NULL;
2454 
2455         if ((s->shutdown & SSL_SENT_SHUTDOWN) != 0) {
2456             /*
2457              * We already sent close_notify. This can only happen in TLSv1.3
2458              * post-handshake messages. We can't reasonably respond to this, so
2459              * we just ignore it
2460              */
2461             return MSG_PROCESS_FINISHED_READING;
2462         }
2463 
2464         /* Free and zero certificate types: it is not present in TLS 1.3 */
2465         OPENSSL_free(s->s3->tmp.ctype);
2466         s->s3->tmp.ctype = NULL;
2467         s->s3->tmp.ctype_len = 0;
2468         OPENSSL_free(s->pha_context);
2469         s->pha_context = NULL;
2470 
2471         if (!PACKET_get_length_prefixed_1(pkt, &reqctx) ||
2472             !PACKET_memdup(&reqctx, &s->pha_context, &s->pha_context_len)) {
2473             SSLfatal(s, SSL_AD_DECODE_ERROR,
2474                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2475                      SSL_R_LENGTH_MISMATCH);
2476             return MSG_PROCESS_ERROR;
2477         }
2478 
2479         if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
2480             SSLfatal(s, SSL_AD_DECODE_ERROR,
2481                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2482                      SSL_R_BAD_LENGTH);
2483             return MSG_PROCESS_ERROR;
2484         }
2485         if (!tls_collect_extensions(s, &extensions,
2486                                     SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
2487                                     &rawexts, NULL, 1)
2488             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
2489                                          rawexts, NULL, 0, 1)) {
2490             /* SSLfatal() already called */
2491             OPENSSL_free(rawexts);
2492             return MSG_PROCESS_ERROR;
2493         }
2494         OPENSSL_free(rawexts);
2495         if (!tls1_process_sigalgs(s)) {
2496             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2497                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2498                      SSL_R_BAD_LENGTH);
2499             return MSG_PROCESS_ERROR;
2500         }
2501     } else {
2502         PACKET ctypes;
2503 
2504         /* get the certificate types */
2505         if (!PACKET_get_length_prefixed_1(pkt, &ctypes)) {
2506             SSLfatal(s, SSL_AD_DECODE_ERROR,
2507                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2508                      SSL_R_LENGTH_MISMATCH);
2509             return MSG_PROCESS_ERROR;
2510         }
2511 
2512         if (!PACKET_memdup(&ctypes, &s->s3->tmp.ctype, &s->s3->tmp.ctype_len)) {
2513             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2514                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2515                      ERR_R_INTERNAL_ERROR);
2516             return MSG_PROCESS_ERROR;
2517         }
2518 
2519         if (SSL_USE_SIGALGS(s)) {
2520             PACKET sigalgs;
2521 
2522             if (!PACKET_get_length_prefixed_2(pkt, &sigalgs)) {
2523                 SSLfatal(s, SSL_AD_DECODE_ERROR,
2524                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2525                          SSL_R_LENGTH_MISMATCH);
2526                 return MSG_PROCESS_ERROR;
2527             }
2528 
2529             /*
2530              * Despite this being for certificates, preserve compatibility
2531              * with pre-TLS 1.3 and use the regular sigalgs field.
2532              */
2533             if (!tls1_save_sigalgs(s, &sigalgs, 0)) {
2534                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2535                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2536                          SSL_R_SIGNATURE_ALGORITHMS_ERROR);
2537                 return MSG_PROCESS_ERROR;
2538             }
2539             if (!tls1_process_sigalgs(s)) {
2540                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2541                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2542                          ERR_R_MALLOC_FAILURE);
2543                 return MSG_PROCESS_ERROR;
2544             }
2545         }
2546 
2547         /* get the CA RDNs */
2548         if (!parse_ca_names(s, pkt)) {
2549             /* SSLfatal() already called */
2550             return MSG_PROCESS_ERROR;
2551         }
2552     }
2553 
2554     if (PACKET_remaining(pkt) != 0) {
2555         SSLfatal(s, SSL_AD_DECODE_ERROR,
2556                  SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2557                  SSL_R_LENGTH_MISMATCH);
2558         return MSG_PROCESS_ERROR;
2559     }
2560 
2561     /* we should setup a certificate to return.... */
2562     s->s3->tmp.cert_req = 1;
2563 
2564     /*
2565      * In TLSv1.3 we don't prepare the client certificate yet. We wait until
2566      * after the CertificateVerify message has been received. This is because
2567      * in TLSv1.3 the CertificateRequest arrives before the Certificate message
2568      * but in TLSv1.2 it is the other way around. We want to make sure that
2569      * SSL_get_peer_certificate() returns something sensible in
2570      * client_cert_cb.
2571      */
2572     if (SSL_IS_TLS13(s) && s->post_handshake_auth != SSL_PHA_REQUESTED)
2573         return MSG_PROCESS_CONTINUE_READING;
2574 
2575     return MSG_PROCESS_CONTINUE_PROCESSING;
2576 }
2577 
2578 MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
2579 {
2580     unsigned int ticklen;
2581     unsigned long ticket_lifetime_hint, age_add = 0;
2582     unsigned int sess_len;
2583     RAW_EXTENSION *exts = NULL;
2584     PACKET nonce;
2585 
2586     PACKET_null_init(&nonce);
2587 
2588     if (!PACKET_get_net_4(pkt, &ticket_lifetime_hint)
2589         || (SSL_IS_TLS13(s)
2590             && (!PACKET_get_net_4(pkt, &age_add)
2591                 || !PACKET_get_length_prefixed_1(pkt, &nonce)))
2592         || !PACKET_get_net_2(pkt, &ticklen)
2593         || (SSL_IS_TLS13(s) ? (ticklen == 0 || PACKET_remaining(pkt) < ticklen)
2594                             : PACKET_remaining(pkt) != ticklen)) {
2595         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2596                  SSL_R_LENGTH_MISMATCH);
2597         goto err;
2598     }
2599 
2600     /*
2601      * Server is allowed to change its mind (in <=TLSv1.2) and send an empty
2602      * ticket. We already checked this TLSv1.3 case above, so it should never
2603      * be 0 here in that instance
2604      */
2605     if (ticklen == 0)
2606         return MSG_PROCESS_CONTINUE_READING;
2607 
2608     /*
2609      * Sessions must be immutable once they go into the session cache. Otherwise
2610      * we can get multi-thread problems. Therefore we don't "update" sessions,
2611      * we replace them with a duplicate. In TLSv1.3 we need to do this every
2612      * time a NewSessionTicket arrives because those messages arrive
2613      * post-handshake and the session may have already gone into the session
2614      * cache.
2615      */
2616     if (SSL_IS_TLS13(s) || s->session->session_id_length > 0) {
2617         SSL_SESSION *new_sess;
2618 
2619         /*
2620          * We reused an existing session, so we need to replace it with a new
2621          * one
2622          */
2623         if ((new_sess = ssl_session_dup(s->session, 0)) == 0) {
2624             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2625                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2626                      ERR_R_MALLOC_FAILURE);
2627             goto err;
2628         }
2629 
2630         if ((s->session_ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) != 0
2631                 && !SSL_IS_TLS13(s)) {
2632             /*
2633              * In TLSv1.2 and below the arrival of a new tickets signals that
2634              * any old ticket we were using is now out of date, so we remove the
2635              * old session from the cache. We carry on if this fails
2636              */
2637             SSL_CTX_remove_session(s->session_ctx, s->session);
2638         }
2639 
2640         SSL_SESSION_free(s->session);
2641         s->session = new_sess;
2642     }
2643 
2644     /*
2645      * Technically the cast to long here is not guaranteed by the C standard -
2646      * but we use it elsewhere, so this should be ok.
2647      */
2648     s->session->time = (long)time(NULL);
2649 
2650     OPENSSL_free(s->session->ext.tick);
2651     s->session->ext.tick = NULL;
2652     s->session->ext.ticklen = 0;
2653 
2654     s->session->ext.tick = OPENSSL_malloc(ticklen);
2655     if (s->session->ext.tick == NULL) {
2656         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2657                  ERR_R_MALLOC_FAILURE);
2658         goto err;
2659     }
2660     if (!PACKET_copy_bytes(pkt, s->session->ext.tick, ticklen)) {
2661         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2662                  SSL_R_LENGTH_MISMATCH);
2663         goto err;
2664     }
2665 
2666     s->session->ext.tick_lifetime_hint = ticket_lifetime_hint;
2667     s->session->ext.tick_age_add = age_add;
2668     s->session->ext.ticklen = ticklen;
2669 
2670     if (SSL_IS_TLS13(s)) {
2671         PACKET extpkt;
2672 
2673         if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
2674                 || PACKET_remaining(pkt) != 0) {
2675             SSLfatal(s, SSL_AD_DECODE_ERROR,
2676                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2677                      SSL_R_LENGTH_MISMATCH);
2678             goto err;
2679         }
2680 
2681         if (!tls_collect_extensions(s, &extpkt,
2682                                     SSL_EXT_TLS1_3_NEW_SESSION_TICKET, &exts,
2683                                     NULL, 1)
2684                 || !tls_parse_all_extensions(s,
2685                                              SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
2686                                              exts, NULL, 0, 1)) {
2687             /* SSLfatal() already called */
2688             goto err;
2689         }
2690     }
2691 
2692     /*
2693      * There are two ways to detect a resumed ticket session. One is to set
2694      * an appropriate session ID and then the server must return a match in
2695      * ServerHello. This allows the normal client session ID matching to work
2696      * and we know much earlier that the ticket has been accepted. The
2697      * other way is to set zero length session ID when the ticket is
2698      * presented and rely on the handshake to determine session resumption.
2699      * We choose the former approach because this fits in with assumptions
2700      * elsewhere in OpenSSL. The session ID is set to the SHA256 (or SHA1 is
2701      * SHA256 is disabled) hash of the ticket.
2702      */
2703     /*
2704      * TODO(size_t): we use sess_len here because EVP_Digest expects an int
2705      * but s->session->session_id_length is a size_t
2706      */
2707     if (!EVP_Digest(s->session->ext.tick, ticklen,
2708                     s->session->session_id, &sess_len,
2709                     EVP_sha256(), NULL)) {
2710         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2711                  ERR_R_EVP_LIB);
2712         goto err;
2713     }
2714     s->session->session_id_length = sess_len;
2715     s->session->not_resumable = 0;
2716 
2717     /* This is a standalone message in TLSv1.3, so there is no more to read */
2718     if (SSL_IS_TLS13(s)) {
2719         const EVP_MD *md = ssl_handshake_md(s);
2720         int hashleni = EVP_MD_size(md);
2721         size_t hashlen;
2722         static const unsigned char nonce_label[] = "resumption";
2723 
2724         /* Ensure cast to size_t is safe */
2725         if (!ossl_assert(hashleni >= 0)) {
2726             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2727                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2728                      ERR_R_INTERNAL_ERROR);
2729             goto err;
2730         }
2731         hashlen = (size_t)hashleni;
2732 
2733         if (!tls13_hkdf_expand(s, md, s->resumption_master_secret,
2734                                nonce_label,
2735                                sizeof(nonce_label) - 1,
2736                                PACKET_data(&nonce),
2737                                PACKET_remaining(&nonce),
2738                                s->session->master_key,
2739                                hashlen, 1)) {
2740             /* SSLfatal() already called */
2741             goto err;
2742         }
2743         s->session->master_key_length = hashlen;
2744 
2745         OPENSSL_free(exts);
2746         ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
2747         return MSG_PROCESS_FINISHED_READING;
2748     }
2749 
2750     return MSG_PROCESS_CONTINUE_READING;
2751  err:
2752     OPENSSL_free(exts);
2753     return MSG_PROCESS_ERROR;
2754 }
2755 
2756 /*
2757  * In TLSv1.3 this is called from the extensions code, otherwise it is used to
2758  * parse a separate message. Returns 1 on success or 0 on failure
2759  */
2760 int tls_process_cert_status_body(SSL *s, PACKET *pkt)
2761 {
2762     size_t resplen;
2763     unsigned int type;
2764 
2765     if (!PACKET_get_1(pkt, &type)
2766         || type != TLSEXT_STATUSTYPE_ocsp) {
2767         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2768                  SSL_R_UNSUPPORTED_STATUS_TYPE);
2769         return 0;
2770     }
2771     if (!PACKET_get_net_3_len(pkt, &resplen)
2772         || PACKET_remaining(pkt) != resplen) {
2773         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2774                  SSL_R_LENGTH_MISMATCH);
2775         return 0;
2776     }
2777     s->ext.ocsp.resp = OPENSSL_malloc(resplen);
2778     if (s->ext.ocsp.resp == NULL) {
2779         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2780                  ERR_R_MALLOC_FAILURE);
2781         return 0;
2782     }
2783     if (!PACKET_copy_bytes(pkt, s->ext.ocsp.resp, resplen)) {
2784         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2785                  SSL_R_LENGTH_MISMATCH);
2786         return 0;
2787     }
2788     s->ext.ocsp.resp_len = resplen;
2789 
2790     return 1;
2791 }
2792 
2793 
2794 MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt)
2795 {
2796     if (!tls_process_cert_status_body(s, pkt)) {
2797         /* SSLfatal() already called */
2798         return MSG_PROCESS_ERROR;
2799     }
2800 
2801     return MSG_PROCESS_CONTINUE_READING;
2802 }
2803 
2804 /*
2805  * Perform miscellaneous checks and processing after we have received the
2806  * server's initial flight. In TLS1.3 this is after the Server Finished message.
2807  * In <=TLS1.2 this is after the ServerDone message. Returns 1 on success or 0
2808  * on failure.
2809  */
2810 int tls_process_initial_server_flight(SSL *s)
2811 {
2812     /*
2813      * at this point we check that we have the required stuff from
2814      * the server
2815      */
2816     if (!ssl3_check_cert_and_algorithm(s)) {
2817         /* SSLfatal() already called */
2818         return 0;
2819     }
2820 
2821     /*
2822      * Call the ocsp status callback if needed. The |ext.ocsp.resp| and
2823      * |ext.ocsp.resp_len| values will be set if we actually received a status
2824      * message, or NULL and -1 otherwise
2825      */
2826     if (s->ext.status_type != TLSEXT_STATUSTYPE_nothing
2827             && s->ctx->ext.status_cb != NULL) {
2828         int ret = s->ctx->ext.status_cb(s, s->ctx->ext.status_arg);
2829 
2830         if (ret == 0) {
2831             SSLfatal(s, SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE,
2832                      SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
2833                      SSL_R_INVALID_STATUS_RESPONSE);
2834             return 0;
2835         }
2836         if (ret < 0) {
2837             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2838                      SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
2839                      ERR_R_MALLOC_FAILURE);
2840             return 0;
2841         }
2842     }
2843 #ifndef OPENSSL_NO_CT
2844     if (s->ct_validation_callback != NULL) {
2845         /* Note we validate the SCTs whether or not we abort on error */
2846         if (!ssl_validate_ct(s) && (s->verify_mode & SSL_VERIFY_PEER)) {
2847             /* SSLfatal() already called */
2848             return 0;
2849         }
2850     }
2851 #endif
2852 
2853     return 1;
2854 }
2855 
2856 MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt)
2857 {
2858     if (PACKET_remaining(pkt) > 0) {
2859         /* should contain no data */
2860         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
2861                  SSL_R_LENGTH_MISMATCH);
2862         return MSG_PROCESS_ERROR;
2863     }
2864 #ifndef OPENSSL_NO_SRP
2865     if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
2866         if (SRP_Calc_A_param(s) <= 0) {
2867             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
2868                      SSL_R_SRP_A_CALC);
2869             return MSG_PROCESS_ERROR;
2870         }
2871     }
2872 #endif
2873 
2874     if (!tls_process_initial_server_flight(s)) {
2875         /* SSLfatal() already called */
2876         return MSG_PROCESS_ERROR;
2877     }
2878 
2879     return MSG_PROCESS_FINISHED_READING;
2880 }
2881 
2882 static int tls_construct_cke_psk_preamble(SSL *s, WPACKET *pkt)
2883 {
2884 #ifndef OPENSSL_NO_PSK
2885     int ret = 0;
2886     /*
2887      * The callback needs PSK_MAX_IDENTITY_LEN + 1 bytes to return a
2888      * \0-terminated identity. The last byte is for us for simulating
2889      * strnlen.
2890      */
2891     char identity[PSK_MAX_IDENTITY_LEN + 1];
2892     size_t identitylen = 0;
2893     unsigned char psk[PSK_MAX_PSK_LEN];
2894     unsigned char *tmppsk = NULL;
2895     char *tmpidentity = NULL;
2896     size_t psklen = 0;
2897 
2898     if (s->psk_client_callback == NULL) {
2899         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2900                  SSL_R_PSK_NO_CLIENT_CB);
2901         goto err;
2902     }
2903 
2904     memset(identity, 0, sizeof(identity));
2905 
2906     psklen = s->psk_client_callback(s, s->session->psk_identity_hint,
2907                                     identity, sizeof(identity) - 1,
2908                                     psk, sizeof(psk));
2909 
2910     if (psklen > PSK_MAX_PSK_LEN) {
2911         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2912                  SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
2913         goto err;
2914     } else if (psklen == 0) {
2915         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2916                  SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2917                  SSL_R_PSK_IDENTITY_NOT_FOUND);
2918         goto err;
2919     }
2920 
2921     identitylen = strlen(identity);
2922     if (identitylen > PSK_MAX_IDENTITY_LEN) {
2923         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2924                  ERR_R_INTERNAL_ERROR);
2925         goto err;
2926     }
2927 
2928     tmppsk = OPENSSL_memdup(psk, psklen);
2929     tmpidentity = OPENSSL_strdup(identity);
2930     if (tmppsk == NULL || tmpidentity == NULL) {
2931         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2932                  ERR_R_MALLOC_FAILURE);
2933         goto err;
2934     }
2935 
2936     OPENSSL_free(s->s3->tmp.psk);
2937     s->s3->tmp.psk = tmppsk;
2938     s->s3->tmp.psklen = psklen;
2939     tmppsk = NULL;
2940     OPENSSL_free(s->session->psk_identity);
2941     s->session->psk_identity = tmpidentity;
2942     tmpidentity = NULL;
2943 
2944     if (!WPACKET_sub_memcpy_u16(pkt, identity, identitylen))  {
2945         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2946                  ERR_R_INTERNAL_ERROR);
2947         goto err;
2948     }
2949 
2950     ret = 1;
2951 
2952  err:
2953     OPENSSL_cleanse(psk, psklen);
2954     OPENSSL_cleanse(identity, sizeof(identity));
2955     OPENSSL_clear_free(tmppsk, psklen);
2956     OPENSSL_clear_free(tmpidentity, identitylen);
2957 
2958     return ret;
2959 #else
2960     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2961              ERR_R_INTERNAL_ERROR);
2962     return 0;
2963 #endif
2964 }
2965 
2966 static int tls_construct_cke_rsa(SSL *s, WPACKET *pkt)
2967 {
2968 #ifndef OPENSSL_NO_RSA
2969     unsigned char *encdata = NULL;
2970     EVP_PKEY *pkey = NULL;
2971     EVP_PKEY_CTX *pctx = NULL;
2972     size_t enclen;
2973     unsigned char *pms = NULL;
2974     size_t pmslen = 0;
2975 
2976     if (s->session->peer == NULL) {
2977         /*
2978          * We should always have a server certificate with SSL_kRSA.
2979          */
2980         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2981                  ERR_R_INTERNAL_ERROR);
2982         return 0;
2983     }
2984 
2985     pkey = X509_get0_pubkey(s->session->peer);
2986     if (EVP_PKEY_get0_RSA(pkey) == NULL) {
2987         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2988                  ERR_R_INTERNAL_ERROR);
2989         return 0;
2990     }
2991 
2992     pmslen = SSL_MAX_MASTER_KEY_LENGTH;
2993     pms = OPENSSL_malloc(pmslen);
2994     if (pms == NULL) {
2995         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2996                  ERR_R_MALLOC_FAILURE);
2997         return 0;
2998     }
2999 
3000     pms[0] = s->client_version >> 8;
3001     pms[1] = s->client_version & 0xff;
3002     /* TODO(size_t): Convert this function */
3003     if (RAND_bytes(pms + 2, (int)(pmslen - 2)) <= 0) {
3004         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3005                  ERR_R_MALLOC_FAILURE);
3006         goto err;
3007     }
3008 
3009     /* Fix buf for TLS and beyond */
3010     if (s->version > SSL3_VERSION && !WPACKET_start_sub_packet_u16(pkt)) {
3011         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3012                  ERR_R_INTERNAL_ERROR);
3013         goto err;
3014     }
3015     pctx = EVP_PKEY_CTX_new(pkey, NULL);
3016     if (pctx == NULL || EVP_PKEY_encrypt_init(pctx) <= 0
3017         || EVP_PKEY_encrypt(pctx, NULL, &enclen, pms, pmslen) <= 0) {
3018         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3019                  ERR_R_EVP_LIB);
3020         goto err;
3021     }
3022     if (!WPACKET_allocate_bytes(pkt, enclen, &encdata)
3023             || EVP_PKEY_encrypt(pctx, encdata, &enclen, pms, pmslen) <= 0) {
3024         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3025                  SSL_R_BAD_RSA_ENCRYPT);
3026         goto err;
3027     }
3028     EVP_PKEY_CTX_free(pctx);
3029     pctx = NULL;
3030 
3031     /* Fix buf for TLS and beyond */
3032     if (s->version > SSL3_VERSION && !WPACKET_close(pkt)) {
3033         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3034                  ERR_R_INTERNAL_ERROR);
3035         goto err;
3036     }
3037 
3038     /* Log the premaster secret, if logging is enabled. */
3039     if (!ssl_log_rsa_client_key_exchange(s, encdata, enclen, pms, pmslen)) {
3040         /* SSLfatal() already called */
3041         goto err;
3042     }
3043 
3044     s->s3->tmp.pms = pms;
3045     s->s3->tmp.pmslen = pmslen;
3046 
3047     return 1;
3048  err:
3049     OPENSSL_clear_free(pms, pmslen);
3050     EVP_PKEY_CTX_free(pctx);
3051 
3052     return 0;
3053 #else
3054     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3055              ERR_R_INTERNAL_ERROR);
3056     return 0;
3057 #endif
3058 }
3059 
3060 static int tls_construct_cke_dhe(SSL *s, WPACKET *pkt)
3061 {
3062 #ifndef OPENSSL_NO_DH
3063     DH *dh_clnt = NULL;
3064     const BIGNUM *pub_key;
3065     EVP_PKEY *ckey = NULL, *skey = NULL;
3066     unsigned char *keybytes = NULL;
3067 
3068     skey = s->s3->peer_tmp;
3069     if (skey == NULL) {
3070         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3071                  ERR_R_INTERNAL_ERROR);
3072         goto err;
3073     }
3074 
3075     ckey = ssl_generate_pkey(skey);
3076     if (ckey == NULL) {
3077         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3078                  ERR_R_INTERNAL_ERROR);
3079         goto err;
3080     }
3081 
3082     dh_clnt = EVP_PKEY_get0_DH(ckey);
3083 
3084     if (dh_clnt == NULL) {
3085         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3086                  ERR_R_INTERNAL_ERROR);
3087         goto err;
3088     }
3089 
3090     if (ssl_derive(s, ckey, skey, 0) == 0) {
3091         /* SSLfatal() already called */
3092         goto err;
3093     }
3094 
3095     /* send off the data */
3096     DH_get0_key(dh_clnt, &pub_key, NULL);
3097     if (!WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(pub_key),
3098                                         &keybytes)) {
3099         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3100                  ERR_R_INTERNAL_ERROR);
3101         goto err;
3102     }
3103 
3104     BN_bn2bin(pub_key, keybytes);
3105     EVP_PKEY_free(ckey);
3106 
3107     return 1;
3108  err:
3109     EVP_PKEY_free(ckey);
3110     return 0;
3111 #else
3112     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3113              ERR_R_INTERNAL_ERROR);
3114     return 0;
3115 #endif
3116 }
3117 
3118 static int tls_construct_cke_ecdhe(SSL *s, WPACKET *pkt)
3119 {
3120 #ifndef OPENSSL_NO_EC
3121     unsigned char *encodedPoint = NULL;
3122     size_t encoded_pt_len = 0;
3123     EVP_PKEY *ckey = NULL, *skey = NULL;
3124     int ret = 0;
3125 
3126     skey = s->s3->peer_tmp;
3127     if (skey == NULL) {
3128         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3129                  ERR_R_INTERNAL_ERROR);
3130         return 0;
3131     }
3132 
3133     ckey = ssl_generate_pkey(skey);
3134     if (ckey == NULL) {
3135         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3136                  ERR_R_MALLOC_FAILURE);
3137         goto err;
3138     }
3139 
3140     if (ssl_derive(s, ckey, skey, 0) == 0) {
3141         /* SSLfatal() already called */
3142         goto err;
3143     }
3144 
3145     /* Generate encoding of client key */
3146     encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(ckey, &encodedPoint);
3147 
3148     if (encoded_pt_len == 0) {
3149         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3150                  ERR_R_EC_LIB);
3151         goto err;
3152     }
3153 
3154     if (!WPACKET_sub_memcpy_u8(pkt, encodedPoint, encoded_pt_len)) {
3155         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3156                  ERR_R_INTERNAL_ERROR);
3157         goto err;
3158     }
3159 
3160     ret = 1;
3161  err:
3162     OPENSSL_free(encodedPoint);
3163     EVP_PKEY_free(ckey);
3164     return ret;
3165 #else
3166     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3167              ERR_R_INTERNAL_ERROR);
3168     return 0;
3169 #endif
3170 }
3171 
3172 static int tls_construct_cke_gost(SSL *s, WPACKET *pkt)
3173 {
3174 #ifndef OPENSSL_NO_GOST
3175     /* GOST key exchange message creation */
3176     EVP_PKEY_CTX *pkey_ctx = NULL;
3177     X509 *peer_cert;
3178     size_t msglen;
3179     unsigned int md_len;
3180     unsigned char shared_ukm[32], tmp[256];
3181     EVP_MD_CTX *ukm_hash = NULL;
3182     int dgst_nid = NID_id_GostR3411_94;
3183     unsigned char *pms = NULL;
3184     size_t pmslen = 0;
3185 
3186     if ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aGOST12) != 0)
3187         dgst_nid = NID_id_GostR3411_2012_256;
3188 
3189     /*
3190      * Get server certificate PKEY and create ctx from it
3191      */
3192     peer_cert = s->session->peer;
3193     if (!peer_cert) {
3194         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3195                SSL_R_NO_GOST_CERTIFICATE_SENT_BY_PEER);
3196         return 0;
3197     }
3198 
3199     pkey_ctx = EVP_PKEY_CTX_new(X509_get0_pubkey(peer_cert), NULL);
3200     if (pkey_ctx == NULL) {
3201         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3202                  ERR_R_MALLOC_FAILURE);
3203         return 0;
3204     }
3205     /*
3206      * If we have send a certificate, and certificate key
3207      * parameters match those of server certificate, use
3208      * certificate key for key exchange
3209      */
3210 
3211     /* Otherwise, generate ephemeral key pair */
3212     pmslen = 32;
3213     pms = OPENSSL_malloc(pmslen);
3214     if (pms == NULL) {
3215         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3216                  ERR_R_MALLOC_FAILURE);
3217         goto err;
3218     }
3219 
3220     if (EVP_PKEY_encrypt_init(pkey_ctx) <= 0
3221         /* Generate session key
3222          * TODO(size_t): Convert this function
3223          */
3224         || RAND_bytes(pms, (int)pmslen) <= 0) {
3225         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3226                  ERR_R_INTERNAL_ERROR);
3227         goto err;
3228     };
3229     /*
3230      * Compute shared IV and store it in algorithm-specific context
3231      * data
3232      */
3233     ukm_hash = EVP_MD_CTX_new();
3234     if (ukm_hash == NULL
3235         || EVP_DigestInit(ukm_hash, EVP_get_digestbynid(dgst_nid)) <= 0
3236         || EVP_DigestUpdate(ukm_hash, s->s3->client_random,
3237                             SSL3_RANDOM_SIZE) <= 0
3238         || EVP_DigestUpdate(ukm_hash, s->s3->server_random,
3239                             SSL3_RANDOM_SIZE) <= 0
3240         || EVP_DigestFinal_ex(ukm_hash, shared_ukm, &md_len) <= 0) {
3241         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3242                  ERR_R_INTERNAL_ERROR);
3243         goto err;
3244     }
3245     EVP_MD_CTX_free(ukm_hash);
3246     ukm_hash = NULL;
3247     if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, EVP_PKEY_OP_ENCRYPT,
3248                           EVP_PKEY_CTRL_SET_IV, 8, shared_ukm) < 0) {
3249         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3250                  SSL_R_LIBRARY_BUG);
3251         goto err;
3252     }
3253     /* Make GOST keytransport blob message */
3254     /*
3255      * Encapsulate it into sequence
3256      */
3257     msglen = 255;
3258     if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) <= 0) {
3259         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3260                  SSL_R_LIBRARY_BUG);
3261         goto err;
3262     }
3263 
3264     if (!WPACKET_put_bytes_u8(pkt, V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)
3265             || (msglen >= 0x80 && !WPACKET_put_bytes_u8(pkt, 0x81))
3266             || !WPACKET_sub_memcpy_u8(pkt, tmp, msglen)) {
3267         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3268                  ERR_R_INTERNAL_ERROR);
3269         goto err;
3270     }
3271 
3272     EVP_PKEY_CTX_free(pkey_ctx);
3273     s->s3->tmp.pms = pms;
3274     s->s3->tmp.pmslen = pmslen;
3275 
3276     return 1;
3277  err:
3278     EVP_PKEY_CTX_free(pkey_ctx);
3279     OPENSSL_clear_free(pms, pmslen);
3280     EVP_MD_CTX_free(ukm_hash);
3281     return 0;
3282 #else
3283     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3284              ERR_R_INTERNAL_ERROR);
3285     return 0;
3286 #endif
3287 }
3288 
3289 static int tls_construct_cke_srp(SSL *s, WPACKET *pkt)
3290 {
3291 #ifndef OPENSSL_NO_SRP
3292     unsigned char *abytes = NULL;
3293 
3294     if (s->srp_ctx.A == NULL
3295             || !WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(s->srp_ctx.A),
3296                                                &abytes)) {
3297         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3298                  ERR_R_INTERNAL_ERROR);
3299         return 0;
3300     }
3301     BN_bn2bin(s->srp_ctx.A, abytes);
3302 
3303     OPENSSL_free(s->session->srp_username);
3304     s->session->srp_username = OPENSSL_strdup(s->srp_ctx.login);
3305     if (s->session->srp_username == NULL) {
3306         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3307                  ERR_R_MALLOC_FAILURE);
3308         return 0;
3309     }
3310 
3311     return 1;
3312 #else
3313     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3314              ERR_R_INTERNAL_ERROR);
3315     return 0;
3316 #endif
3317 }
3318 
3319 int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt)
3320 {
3321     unsigned long alg_k;
3322 
3323     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3324 
3325     /*
3326      * All of the construct functions below call SSLfatal() if necessary so
3327      * no need to do so here.
3328      */
3329     if ((alg_k & SSL_PSK)
3330         && !tls_construct_cke_psk_preamble(s, pkt))
3331         goto err;
3332 
3333     if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
3334         if (!tls_construct_cke_rsa(s, pkt))
3335             goto err;
3336     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
3337         if (!tls_construct_cke_dhe(s, pkt))
3338             goto err;
3339     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
3340         if (!tls_construct_cke_ecdhe(s, pkt))
3341             goto err;
3342     } else if (alg_k & SSL_kGOST) {
3343         if (!tls_construct_cke_gost(s, pkt))
3344             goto err;
3345     } else if (alg_k & SSL_kSRP) {
3346         if (!tls_construct_cke_srp(s, pkt))
3347             goto err;
3348     } else if (!(alg_k & SSL_kPSK)) {
3349         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3350                  SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
3351         goto err;
3352     }
3353 
3354     return 1;
3355  err:
3356     OPENSSL_clear_free(s->s3->tmp.pms, s->s3->tmp.pmslen);
3357     s->s3->tmp.pms = NULL;
3358 #ifndef OPENSSL_NO_PSK
3359     OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);
3360     s->s3->tmp.psk = NULL;
3361 #endif
3362     return 0;
3363 }
3364 
3365 int tls_client_key_exchange_post_work(SSL *s)
3366 {
3367     unsigned char *pms = NULL;
3368     size_t pmslen = 0;
3369 
3370     pms = s->s3->tmp.pms;
3371     pmslen = s->s3->tmp.pmslen;
3372 
3373 #ifndef OPENSSL_NO_SRP
3374     /* Check for SRP */
3375     if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
3376         if (!srp_generate_client_master_secret(s)) {
3377             /* SSLfatal() already called */
3378             goto err;
3379         }
3380         return 1;
3381     }
3382 #endif
3383 
3384     if (pms == NULL && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
3385         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3386                  SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK, ERR_R_MALLOC_FAILURE);
3387         goto err;
3388     }
3389     if (!ssl_generate_master_secret(s, pms, pmslen, 1)) {
3390         /* SSLfatal() already called */
3391         /* ssl_generate_master_secret frees the pms even on error */
3392         pms = NULL;
3393         pmslen = 0;
3394         goto err;
3395     }
3396     pms = NULL;
3397     pmslen = 0;
3398 
3399 #ifndef OPENSSL_NO_SCTP
3400     if (SSL_IS_DTLS(s)) {
3401         unsigned char sctpauthkey[64];
3402         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
3403         size_t labellen;
3404 
3405         /*
3406          * Add new shared key for SCTP-Auth, will be ignored if no SCTP
3407          * used.
3408          */
3409         memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
3410                sizeof(DTLS1_SCTP_AUTH_LABEL));
3411 
3412         /* Don't include the terminating zero. */
3413         labellen = sizeof(labelbuffer) - 1;
3414         if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
3415             labellen += 1;
3416 
3417         if (SSL_export_keying_material(s, sctpauthkey,
3418                                        sizeof(sctpauthkey), labelbuffer,
3419                                        labellen, NULL, 0, 0) <= 0) {
3420             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3421                      SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK,
3422                      ERR_R_INTERNAL_ERROR);
3423             goto err;
3424         }
3425 
3426         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
3427                  sizeof(sctpauthkey), sctpauthkey);
3428     }
3429 #endif
3430 
3431     return 1;
3432  err:
3433     OPENSSL_clear_free(pms, pmslen);
3434     s->s3->tmp.pms = NULL;
3435     return 0;
3436 }
3437 
3438 /*
3439  * Check a certificate can be used for client authentication. Currently check
3440  * cert exists, if we have a suitable digest for TLS 1.2 if static DH client
3441  * certificates can be used and optionally checks suitability for Suite B.
3442  */
3443 static int ssl3_check_client_certificate(SSL *s)
3444 {
3445     /* If no suitable signature algorithm can't use certificate */
3446     if (!tls_choose_sigalg(s, 0) || s->s3->tmp.sigalg == NULL)
3447         return 0;
3448     /*
3449      * If strict mode check suitability of chain before using it. This also
3450      * adjusts suite B digest if necessary.
3451      */
3452     if (s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT &&
3453         !tls1_check_chain(s, NULL, NULL, NULL, -2))
3454         return 0;
3455     return 1;
3456 }
3457 
3458 WORK_STATE tls_prepare_client_certificate(SSL *s, WORK_STATE wst)
3459 {
3460     X509 *x509 = NULL;
3461     EVP_PKEY *pkey = NULL;
3462     int i;
3463 
3464     if (wst == WORK_MORE_A) {
3465         /* Let cert callback update client certificates if required */
3466         if (s->cert->cert_cb) {
3467             i = s->cert->cert_cb(s, s->cert->cert_cb_arg);
3468             if (i < 0) {
3469                 s->rwstate = SSL_X509_LOOKUP;
3470                 return WORK_MORE_A;
3471             }
3472             if (i == 0) {
3473                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3474                          SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3475                          SSL_R_CALLBACK_FAILED);
3476                 return WORK_ERROR;
3477             }
3478             s->rwstate = SSL_NOTHING;
3479         }
3480         if (ssl3_check_client_certificate(s)) {
3481             if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
3482                 return WORK_FINISHED_STOP;
3483             }
3484             return WORK_FINISHED_CONTINUE;
3485         }
3486 
3487         /* Fall through to WORK_MORE_B */
3488         wst = WORK_MORE_B;
3489     }
3490 
3491     /* We need to get a client cert */
3492     if (wst == WORK_MORE_B) {
3493         /*
3494          * If we get an error, we need to ssl->rwstate=SSL_X509_LOOKUP;
3495          * return(-1); We then get retied later
3496          */
3497         i = ssl_do_client_cert_cb(s, &x509, &pkey);
3498         if (i < 0) {
3499             s->rwstate = SSL_X509_LOOKUP;
3500             return WORK_MORE_B;
3501         }
3502         s->rwstate = SSL_NOTHING;
3503         if ((i == 1) && (pkey != NULL) && (x509 != NULL)) {
3504             if (!SSL_use_certificate(s, x509) || !SSL_use_PrivateKey(s, pkey))
3505                 i = 0;
3506         } else if (i == 1) {
3507             i = 0;
3508             SSLerr(SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3509                    SSL_R_BAD_DATA_RETURNED_BY_CALLBACK);
3510         }
3511 
3512         X509_free(x509);
3513         EVP_PKEY_free(pkey);
3514         if (i && !ssl3_check_client_certificate(s))
3515             i = 0;
3516         if (i == 0) {
3517             if (s->version == SSL3_VERSION) {
3518                 s->s3->tmp.cert_req = 0;
3519                 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_CERTIFICATE);
3520                 return WORK_FINISHED_CONTINUE;
3521             } else {
3522                 s->s3->tmp.cert_req = 2;
3523                 if (!ssl3_digest_cached_records(s, 0)) {
3524                     /* SSLfatal() already called */
3525                     return WORK_ERROR;
3526                 }
3527             }
3528         }
3529 
3530         if (s->post_handshake_auth == SSL_PHA_REQUESTED)
3531             return WORK_FINISHED_STOP;
3532         return WORK_FINISHED_CONTINUE;
3533     }
3534 
3535     /* Shouldn't ever get here */
3536     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3537              ERR_R_INTERNAL_ERROR);
3538     return WORK_ERROR;
3539 }
3540 
3541 int tls_construct_client_certificate(SSL *s, WPACKET *pkt)
3542 {
3543     if (SSL_IS_TLS13(s)) {
3544         if (s->pha_context == NULL) {
3545             /* no context available, add 0-length context */
3546             if (!WPACKET_put_bytes_u8(pkt, 0)) {
3547                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3548                          SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
3549                 return 0;
3550             }
3551         } else if (!WPACKET_sub_memcpy_u8(pkt, s->pha_context, s->pha_context_len)) {
3552             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3553                      SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
3554             return 0;
3555         }
3556     }
3557     if (!ssl3_output_cert_chain(s, pkt,
3558                                 (s->s3->tmp.cert_req == 2) ? NULL
3559                                                            : s->cert->key)) {
3560         /* SSLfatal() already called */
3561         return 0;
3562     }
3563 
3564     if (SSL_IS_TLS13(s)
3565             && SSL_IS_FIRST_HANDSHAKE(s)
3566             && (!s->method->ssl3_enc->change_cipher_state(s,
3567                     SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_WRITE))) {
3568         /*
3569          * This is a fatal error, which leaves enc_write_ctx in an inconsistent
3570          * state and thus ssl3_send_alert may crash.
3571          */
3572         SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE,
3573                  SSL_R_CANNOT_CHANGE_CIPHER);
3574         return 0;
3575     }
3576 
3577     return 1;
3578 }
3579 
3580 int ssl3_check_cert_and_algorithm(SSL *s)
3581 {
3582     const SSL_CERT_LOOKUP *clu;
3583     size_t idx;
3584     long alg_k, alg_a;
3585 
3586     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3587     alg_a = s->s3->tmp.new_cipher->algorithm_auth;
3588 
3589     /* we don't have a certificate */
3590     if (!(alg_a & SSL_aCERT))
3591         return 1;
3592 
3593     /* This is the passed certificate */
3594     clu = ssl_cert_lookup_by_pkey(X509_get0_pubkey(s->session->peer), &idx);
3595 
3596     /* Check certificate is recognised and suitable for cipher */
3597     if (clu == NULL || (alg_a & clu->amask) == 0) {
3598         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3599                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3600                  SSL_R_MISSING_SIGNING_CERT);
3601         return 0;
3602     }
3603 
3604 #ifndef OPENSSL_NO_EC
3605     if (clu->amask & SSL_aECDSA) {
3606         if (ssl_check_srvr_ecc_cert_and_alg(s->session->peer, s))
3607             return 1;
3608         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3609                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM, SSL_R_BAD_ECC_CERT);
3610         return 0;
3611     }
3612 #endif
3613 #ifndef OPENSSL_NO_RSA
3614     if (alg_k & (SSL_kRSA | SSL_kRSAPSK) && idx != SSL_PKEY_RSA) {
3615         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3616                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3617                  SSL_R_MISSING_RSA_ENCRYPTING_CERT);
3618         return 0;
3619     }
3620 #endif
3621 #ifndef OPENSSL_NO_DH
3622     if ((alg_k & SSL_kDHE) && (s->s3->peer_tmp == NULL)) {
3623         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3624                  ERR_R_INTERNAL_ERROR);
3625         return 0;
3626     }
3627 #endif
3628 
3629     return 1;
3630 }
3631 
3632 #ifndef OPENSSL_NO_NEXTPROTONEG
3633 int tls_construct_next_proto(SSL *s, WPACKET *pkt)
3634 {
3635     size_t len, padding_len;
3636     unsigned char *padding = NULL;
3637 
3638     len = s->ext.npn_len;
3639     padding_len = 32 - ((len + 2) % 32);
3640 
3641     if (!WPACKET_sub_memcpy_u8(pkt, s->ext.npn, len)
3642             || !WPACKET_sub_allocate_bytes_u8(pkt, padding_len, &padding)) {
3643         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_NEXT_PROTO,
3644                  ERR_R_INTERNAL_ERROR);
3645         return 0;
3646     }
3647 
3648     memset(padding, 0, padding_len);
3649 
3650     return 1;
3651 }
3652 #endif
3653 
3654 MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt)
3655 {
3656     if (PACKET_remaining(pkt) > 0) {
3657         /* should contain no data */
3658         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_HELLO_REQ,
3659                  SSL_R_LENGTH_MISMATCH);
3660         return MSG_PROCESS_ERROR;
3661     }
3662 
3663     if ((s->options & SSL_OP_NO_RENEGOTIATION)) {
3664         ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
3665         return MSG_PROCESS_FINISHED_READING;
3666     }
3667 
3668     /*
3669      * This is a historical discrepancy (not in the RFC) maintained for
3670      * compatibility reasons. If a TLS client receives a HelloRequest it will
3671      * attempt an abbreviated handshake. However if a DTLS client receives a
3672      * HelloRequest it will do a full handshake. Either behaviour is reasonable
3673      * but doing one for TLS and another for DTLS is odd.
3674      */
3675     if (SSL_IS_DTLS(s))
3676         SSL_renegotiate(s);
3677     else
3678         SSL_renegotiate_abbreviated(s);
3679 
3680     return MSG_PROCESS_FINISHED_READING;
3681 }
3682 
3683 static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
3684 {
3685     PACKET extensions;
3686     RAW_EXTENSION *rawexts = NULL;
3687 
3688     if (!PACKET_as_length_prefixed_2(pkt, &extensions)
3689             || PACKET_remaining(pkt) != 0) {
3690         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS,
3691                  SSL_R_LENGTH_MISMATCH);
3692         goto err;
3693     }
3694 
3695     if (!tls_collect_extensions(s, &extensions,
3696                                 SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, &rawexts,
3697                                 NULL, 1)
3698             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
3699                                          rawexts, NULL, 0, 1)) {
3700         /* SSLfatal() already called */
3701         goto err;
3702     }
3703 
3704     OPENSSL_free(rawexts);
3705     return MSG_PROCESS_CONTINUE_READING;
3706 
3707  err:
3708     OPENSSL_free(rawexts);
3709     return MSG_PROCESS_ERROR;
3710 }
3711 
3712 int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
3713 {
3714     int i = 0;
3715 #ifndef OPENSSL_NO_ENGINE
3716     if (s->ctx->client_cert_engine) {
3717         i = ENGINE_load_ssl_client_cert(s->ctx->client_cert_engine, s,
3718                                         SSL_get_client_CA_list(s),
3719                                         px509, ppkey, NULL, NULL, NULL);
3720         if (i != 0)
3721             return i;
3722     }
3723 #endif
3724     if (s->ctx->client_cert_cb)
3725         i = s->ctx->client_cert_cb(s, px509, ppkey);
3726     return i;
3727 }
3728 
3729 int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, WPACKET *pkt)
3730 {
3731     int i;
3732     size_t totlen = 0, len, maxlen, maxverok = 0;
3733     int empty_reneg_info_scsv = !s->renegotiate;
3734 
3735     /* Set disabled masks for this session */
3736     if (!ssl_set_client_disabled(s)) {
3737         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3738                  SSL_R_NO_PROTOCOLS_AVAILABLE);
3739         return 0;
3740     }
3741 
3742     if (sk == NULL) {
3743         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3744                  ERR_R_INTERNAL_ERROR);
3745         return 0;
3746     }
3747 
3748 #ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
3749 # if OPENSSL_MAX_TLS1_2_CIPHER_LENGTH < 6
3750 #  error Max cipher length too short
3751 # endif
3752     /*
3753      * Some servers hang if client hello > 256 bytes as hack workaround
3754      * chop number of supported ciphers to keep it well below this if we
3755      * use TLS v1.2
3756      */
3757     if (TLS1_get_version(s) >= TLS1_2_VERSION)
3758         maxlen = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
3759     else
3760 #endif
3761         /* Maximum length that can be stored in 2 bytes. Length must be even */
3762         maxlen = 0xfffe;
3763 
3764     if (empty_reneg_info_scsv)
3765         maxlen -= 2;
3766     if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV)
3767         maxlen -= 2;
3768 
3769     for (i = 0; i < sk_SSL_CIPHER_num(sk) && totlen < maxlen; i++) {
3770         const SSL_CIPHER *c;
3771 
3772         c = sk_SSL_CIPHER_value(sk, i);
3773         /* Skip disabled ciphers */
3774         if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0))
3775             continue;
3776 
3777         if (!s->method->put_cipher_by_char(c, pkt, &len)) {
3778             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3779                      ERR_R_INTERNAL_ERROR);
3780             return 0;
3781         }
3782 
3783         /* Sanity check that the maximum version we offer has ciphers enabled */
3784         if (!maxverok) {
3785             if (SSL_IS_DTLS(s)) {
3786                 if (DTLS_VERSION_GE(c->max_dtls, s->s3->tmp.max_ver)
3787                         && DTLS_VERSION_LE(c->min_dtls, s->s3->tmp.max_ver))
3788                     maxverok = 1;
3789             } else {
3790                 if (c->max_tls >= s->s3->tmp.max_ver
3791                         && c->min_tls <= s->s3->tmp.max_ver)
3792                     maxverok = 1;
3793             }
3794         }
3795 
3796         totlen += len;
3797     }
3798 
3799     if (totlen == 0 || !maxverok) {
3800         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3801                  SSL_R_NO_CIPHERS_AVAILABLE);
3802 
3803         if (!maxverok)
3804             ERR_add_error_data(1, "No ciphers enabled for max supported "
3805                                   "SSL/TLS version");
3806 
3807         return 0;
3808     }
3809 
3810     if (totlen != 0) {
3811         if (empty_reneg_info_scsv) {
3812             static SSL_CIPHER scsv = {
3813                 0, NULL, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
3814             };
3815             if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
3816                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3817                          SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
3818                 return 0;
3819             }
3820         }
3821         if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
3822             static SSL_CIPHER scsv = {
3823                 0, NULL, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
3824             };
3825             if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
3826                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3827                          SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
3828                 return 0;
3829             }
3830         }
3831     }
3832 
3833     return 1;
3834 }
3835 
3836 int tls_construct_end_of_early_data(SSL *s, WPACKET *pkt)
3837 {
3838     if (s->early_data_state != SSL_EARLY_DATA_WRITE_RETRY
3839             && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING) {
3840         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3841                  SSL_F_TLS_CONSTRUCT_END_OF_EARLY_DATA,
3842                  ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
3843         return 0;
3844     }
3845 
3846     s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
3847     return 1;
3848 }
3849