xref: /freebsd/crypto/openssl/ssl/statem/statem_clnt.c (revision 13ea0450a9c8742119d36f3bf8f47accdce46e54)
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                 || (SSL_IS_TLS13(s)
1618                     && s->session->ext.tick_identity
1619                        != TLSEXT_PSK_BAD_IDENTITY)) {
1620             tsan_counter(&s->session_ctx->stats.sess_miss);
1621             if (!ssl_get_new_session(s, 0)) {
1622                 /* SSLfatal() already called */
1623                 goto err;
1624             }
1625         }
1626 
1627         s->session->ssl_version = s->version;
1628         /*
1629          * In TLSv1.2 and below we save the session id we were sent so we can
1630          * resume it later. In TLSv1.3 the session id we were sent is just an
1631          * echo of what we originally sent in the ClientHello and should not be
1632          * used for resumption.
1633          */
1634         if (!SSL_IS_TLS13(s)) {
1635             s->session->session_id_length = session_id_len;
1636             /* session_id_len could be 0 */
1637             if (session_id_len > 0)
1638                 memcpy(s->session->session_id, PACKET_data(&session_id),
1639                        session_id_len);
1640         }
1641     }
1642 
1643     /* Session version and negotiated protocol version should match */
1644     if (s->version != s->session->ssl_version) {
1645         SSLfatal(s, SSL_AD_PROTOCOL_VERSION, SSL_F_TLS_PROCESS_SERVER_HELLO,
1646                  SSL_R_SSL_SESSION_VERSION_MISMATCH);
1647         goto err;
1648     }
1649     /*
1650      * Now that we know the version, update the check to see if it's an allowed
1651      * version.
1652      */
1653     s->s3->tmp.min_ver = s->version;
1654     s->s3->tmp.max_ver = s->version;
1655 
1656     if (!set_client_ciphersuite(s, cipherchars)) {
1657         /* SSLfatal() already called */
1658         goto err;
1659     }
1660 
1661 #ifdef OPENSSL_NO_COMP
1662     if (compression != 0) {
1663         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1664                  SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
1665         goto err;
1666     }
1667     /*
1668      * If compression is disabled we'd better not try to resume a session
1669      * using compression.
1670      */
1671     if (s->session->compress_meth != 0) {
1672         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SERVER_HELLO,
1673                  SSL_R_INCONSISTENT_COMPRESSION);
1674         goto err;
1675     }
1676 #else
1677     if (s->hit && compression != s->session->compress_meth) {
1678         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1679                  SSL_R_OLD_SESSION_COMPRESSION_ALGORITHM_NOT_RETURNED);
1680         goto err;
1681     }
1682     if (compression == 0)
1683         comp = NULL;
1684     else if (!ssl_allow_compression(s)) {
1685         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1686                  SSL_R_COMPRESSION_DISABLED);
1687         goto err;
1688     } else {
1689         comp = ssl3_comp_find(s->ctx->comp_methods, compression);
1690     }
1691 
1692     if (compression != 0 && comp == NULL) {
1693         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SERVER_HELLO,
1694                  SSL_R_UNSUPPORTED_COMPRESSION_ALGORITHM);
1695         goto err;
1696     } else {
1697         s->s3->tmp.new_compression = comp;
1698     }
1699 #endif
1700 
1701     if (!tls_parse_all_extensions(s, context, extensions, NULL, 0, 1)) {
1702         /* SSLfatal() already called */
1703         goto err;
1704     }
1705 
1706 #ifndef OPENSSL_NO_SCTP
1707     if (SSL_IS_DTLS(s) && s->hit) {
1708         unsigned char sctpauthkey[64];
1709         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
1710         size_t labellen;
1711 
1712         /*
1713          * Add new shared key for SCTP-Auth, will be ignored if
1714          * no SCTP used.
1715          */
1716         memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
1717                sizeof(DTLS1_SCTP_AUTH_LABEL));
1718 
1719         /* Don't include the terminating zero. */
1720         labellen = sizeof(labelbuffer) - 1;
1721         if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
1722             labellen += 1;
1723 
1724         if (SSL_export_keying_material(s, sctpauthkey,
1725                                        sizeof(sctpauthkey),
1726                                        labelbuffer,
1727                                        labellen, NULL, 0, 0) <= 0) {
1728             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_HELLO,
1729                      ERR_R_INTERNAL_ERROR);
1730             goto err;
1731         }
1732 
1733         BIO_ctrl(SSL_get_wbio(s),
1734                  BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
1735                  sizeof(sctpauthkey), sctpauthkey);
1736     }
1737 #endif
1738 
1739     /*
1740      * In TLSv1.3 we have some post-processing to change cipher state, otherwise
1741      * we're done with this message
1742      */
1743     if (SSL_IS_TLS13(s)
1744             && (!s->method->ssl3_enc->setup_key_block(s)
1745                 || !s->method->ssl3_enc->change_cipher_state(s,
1746                     SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_READ))) {
1747         /* SSLfatal() already called */
1748         goto err;
1749     }
1750 
1751     OPENSSL_free(extensions);
1752     return MSG_PROCESS_CONTINUE_READING;
1753  err:
1754     OPENSSL_free(extensions);
1755     return MSG_PROCESS_ERROR;
1756 }
1757 
1758 static MSG_PROCESS_RETURN tls_process_as_hello_retry_request(SSL *s,
1759                                                              PACKET *extpkt)
1760 {
1761     RAW_EXTENSION *extensions = NULL;
1762 
1763     /*
1764      * If we were sending early_data then the enc_write_ctx is now invalid and
1765      * should not be used.
1766      */
1767     EVP_CIPHER_CTX_free(s->enc_write_ctx);
1768     s->enc_write_ctx = NULL;
1769 
1770     if (!tls_collect_extensions(s, extpkt, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
1771                                 &extensions, NULL, 1)
1772             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST,
1773                                          extensions, NULL, 0, 1)) {
1774         /* SSLfatal() already called */
1775         goto err;
1776     }
1777 
1778     OPENSSL_free(extensions);
1779     extensions = NULL;
1780 
1781     if (s->ext.tls13_cookie_len == 0
1782 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
1783         && s->s3->tmp.pkey != NULL
1784 #endif
1785         ) {
1786         /*
1787          * We didn't receive a cookie or a new key_share so the next
1788          * ClientHello will not change
1789          */
1790         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1791                  SSL_F_TLS_PROCESS_AS_HELLO_RETRY_REQUEST,
1792                  SSL_R_NO_CHANGE_FOLLOWING_HRR);
1793         goto err;
1794     }
1795 
1796     /*
1797      * Re-initialise the Transcript Hash. We're going to prepopulate it with
1798      * a synthetic message_hash in place of ClientHello1.
1799      */
1800     if (!create_synthetic_message_hash(s, NULL, 0, NULL, 0)) {
1801         /* SSLfatal() already called */
1802         goto err;
1803     }
1804 
1805     /*
1806      * Add this message to the Transcript Hash. Normally this is done
1807      * automatically prior to the message processing stage. However due to the
1808      * need to create the synthetic message hash, we defer that step until now
1809      * for HRR messages.
1810      */
1811     if (!ssl3_finish_mac(s, (unsigned char *)s->init_buf->data,
1812                                 s->init_num + SSL3_HM_HEADER_LENGTH)) {
1813         /* SSLfatal() already called */
1814         goto err;
1815     }
1816 
1817     return MSG_PROCESS_FINISHED_READING;
1818  err:
1819     OPENSSL_free(extensions);
1820     return MSG_PROCESS_ERROR;
1821 }
1822 
1823 MSG_PROCESS_RETURN tls_process_server_certificate(SSL *s, PACKET *pkt)
1824 {
1825     int i;
1826     MSG_PROCESS_RETURN ret = MSG_PROCESS_ERROR;
1827     unsigned long cert_list_len, cert_len;
1828     X509 *x = NULL;
1829     const unsigned char *certstart, *certbytes;
1830     STACK_OF(X509) *sk = NULL;
1831     EVP_PKEY *pkey = NULL;
1832     size_t chainidx, certidx;
1833     unsigned int context = 0;
1834     const SSL_CERT_LOOKUP *clu;
1835 
1836     if ((sk = sk_X509_new_null()) == NULL) {
1837         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1838                  ERR_R_MALLOC_FAILURE);
1839         goto err;
1840     }
1841 
1842     if ((SSL_IS_TLS13(s) && !PACKET_get_1(pkt, &context))
1843             || context != 0
1844             || !PACKET_get_net_3(pkt, &cert_list_len)
1845             || PACKET_remaining(pkt) != cert_list_len
1846             || PACKET_remaining(pkt) == 0) {
1847         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1848                  SSL_R_LENGTH_MISMATCH);
1849         goto err;
1850     }
1851     for (chainidx = 0; PACKET_remaining(pkt); chainidx++) {
1852         if (!PACKET_get_net_3(pkt, &cert_len)
1853             || !PACKET_get_bytes(pkt, &certbytes, cert_len)) {
1854             SSLfatal(s, SSL_AD_DECODE_ERROR,
1855                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1856                      SSL_R_CERT_LENGTH_MISMATCH);
1857             goto err;
1858         }
1859 
1860         certstart = certbytes;
1861         x = d2i_X509(NULL, (const unsigned char **)&certbytes, cert_len);
1862         if (x == NULL) {
1863             SSLfatal(s, SSL_AD_BAD_CERTIFICATE,
1864                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, ERR_R_ASN1_LIB);
1865             goto err;
1866         }
1867         if (certbytes != (certstart + cert_len)) {
1868             SSLfatal(s, SSL_AD_DECODE_ERROR,
1869                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1870                      SSL_R_CERT_LENGTH_MISMATCH);
1871             goto err;
1872         }
1873 
1874         if (SSL_IS_TLS13(s)) {
1875             RAW_EXTENSION *rawexts = NULL;
1876             PACKET extensions;
1877 
1878             if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
1879                 SSLfatal(s, SSL_AD_DECODE_ERROR,
1880                          SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1881                          SSL_R_BAD_LENGTH);
1882                 goto err;
1883             }
1884             if (!tls_collect_extensions(s, &extensions,
1885                                         SSL_EXT_TLS1_3_CERTIFICATE, &rawexts,
1886                                         NULL, chainidx == 0)
1887                 || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE,
1888                                              rawexts, x, chainidx,
1889                                              PACKET_remaining(pkt) == 0)) {
1890                 OPENSSL_free(rawexts);
1891                 /* SSLfatal already called */
1892                 goto err;
1893             }
1894             OPENSSL_free(rawexts);
1895         }
1896 
1897         if (!sk_X509_push(sk, x)) {
1898             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
1899                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1900                      ERR_R_MALLOC_FAILURE);
1901             goto err;
1902         }
1903         x = NULL;
1904     }
1905 
1906     i = ssl_verify_cert_chain(s, sk);
1907     /*
1908      * The documented interface is that SSL_VERIFY_PEER should be set in order
1909      * for client side verification of the server certificate to take place.
1910      * However, historically the code has only checked that *any* flag is set
1911      * to cause server verification to take place. Use of the other flags makes
1912      * no sense in client mode. An attempt to clean up the semantics was
1913      * reverted because at least one application *only* set
1914      * SSL_VERIFY_FAIL_IF_NO_PEER_CERT. Prior to the clean up this still caused
1915      * server verification to take place, after the clean up it silently did
1916      * nothing. SSL_CTX_set_verify()/SSL_set_verify() cannot validate the flags
1917      * sent to them because they are void functions. Therefore, we now use the
1918      * (less clean) historic behaviour of performing validation if any flag is
1919      * set. The *documented* interface remains the same.
1920      */
1921     if (s->verify_mode != SSL_VERIFY_NONE && i <= 0) {
1922         SSLfatal(s, ssl_x509err2alert(s->verify_result),
1923                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1924                  SSL_R_CERTIFICATE_VERIFY_FAILED);
1925         goto err;
1926     }
1927     ERR_clear_error();          /* but we keep s->verify_result */
1928     if (i > 1) {
1929         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
1930                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE, i);
1931         goto err;
1932     }
1933 
1934     s->session->peer_chain = sk;
1935     /*
1936      * Inconsistency alert: cert_chain does include the peer's certificate,
1937      * which we don't include in statem_srvr.c
1938      */
1939     x = sk_X509_value(sk, 0);
1940     sk = NULL;
1941 
1942     pkey = X509_get0_pubkey(x);
1943 
1944     if (pkey == NULL || EVP_PKEY_missing_parameters(pkey)) {
1945         x = NULL;
1946         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1947                  SSL_R_UNABLE_TO_FIND_PUBLIC_KEY_PARAMETERS);
1948         goto err;
1949     }
1950 
1951     if ((clu = ssl_cert_lookup_by_pkey(pkey, &certidx)) == NULL) {
1952         x = NULL;
1953         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1954                  SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1955                  SSL_R_UNKNOWN_CERTIFICATE_TYPE);
1956         goto err;
1957     }
1958     /*
1959      * Check certificate type is consistent with ciphersuite. For TLS 1.3
1960      * skip check since TLS 1.3 ciphersuites can be used with any certificate
1961      * type.
1962      */
1963     if (!SSL_IS_TLS13(s)) {
1964         if ((clu->amask & s->s3->tmp.new_cipher->algorithm_auth) == 0) {
1965             x = NULL;
1966             SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER,
1967                      SSL_F_TLS_PROCESS_SERVER_CERTIFICATE,
1968                      SSL_R_WRONG_CERTIFICATE_TYPE);
1969             goto err;
1970         }
1971     }
1972     s->session->peer_type = certidx;
1973 
1974     X509_free(s->session->peer);
1975     X509_up_ref(x);
1976     s->session->peer = x;
1977     s->session->verify_result = s->verify_result;
1978     x = NULL;
1979 
1980     /* Save the current hash state for when we receive the CertificateVerify */
1981     if (SSL_IS_TLS13(s)
1982             && !ssl_handshake_hash(s, s->cert_verify_hash,
1983                                    sizeof(s->cert_verify_hash),
1984                                    &s->cert_verify_hash_len)) {
1985         /* SSLfatal() already called */;
1986         goto err;
1987     }
1988 
1989     ret = MSG_PROCESS_CONTINUE_READING;
1990 
1991  err:
1992     X509_free(x);
1993     sk_X509_pop_free(sk, X509_free);
1994     return ret;
1995 }
1996 
1997 static int tls_process_ske_psk_preamble(SSL *s, PACKET *pkt)
1998 {
1999 #ifndef OPENSSL_NO_PSK
2000     PACKET psk_identity_hint;
2001 
2002     /* PSK ciphersuites are preceded by an identity hint */
2003 
2004     if (!PACKET_get_length_prefixed_2(pkt, &psk_identity_hint)) {
2005         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2006                  SSL_R_LENGTH_MISMATCH);
2007         return 0;
2008     }
2009 
2010     /*
2011      * Store PSK identity hint for later use, hint is used in
2012      * tls_construct_client_key_exchange.  Assume that the maximum length of
2013      * a PSK identity hint can be as long as the maximum length of a PSK
2014      * identity.
2015      */
2016     if (PACKET_remaining(&psk_identity_hint) > PSK_MAX_IDENTITY_LEN) {
2017         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2018                  SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2019                  SSL_R_DATA_LENGTH_TOO_LONG);
2020         return 0;
2021     }
2022 
2023     if (PACKET_remaining(&psk_identity_hint) == 0) {
2024         OPENSSL_free(s->session->psk_identity_hint);
2025         s->session->psk_identity_hint = NULL;
2026     } else if (!PACKET_strndup(&psk_identity_hint,
2027                                &s->session->psk_identity_hint)) {
2028         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2029                  ERR_R_INTERNAL_ERROR);
2030         return 0;
2031     }
2032 
2033     return 1;
2034 #else
2035     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_PSK_PREAMBLE,
2036              ERR_R_INTERNAL_ERROR);
2037     return 0;
2038 #endif
2039 }
2040 
2041 static int tls_process_ske_srp(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2042 {
2043 #ifndef OPENSSL_NO_SRP
2044     PACKET prime, generator, salt, server_pub;
2045 
2046     if (!PACKET_get_length_prefixed_2(pkt, &prime)
2047         || !PACKET_get_length_prefixed_2(pkt, &generator)
2048         || !PACKET_get_length_prefixed_1(pkt, &salt)
2049         || !PACKET_get_length_prefixed_2(pkt, &server_pub)) {
2050         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2051                  SSL_R_LENGTH_MISMATCH);
2052         return 0;
2053     }
2054 
2055     /* TODO(size_t): Convert BN_bin2bn() calls */
2056     if ((s->srp_ctx.N =
2057          BN_bin2bn(PACKET_data(&prime),
2058                    (int)PACKET_remaining(&prime), NULL)) == NULL
2059         || (s->srp_ctx.g =
2060             BN_bin2bn(PACKET_data(&generator),
2061                       (int)PACKET_remaining(&generator), NULL)) == NULL
2062         || (s->srp_ctx.s =
2063             BN_bin2bn(PACKET_data(&salt),
2064                       (int)PACKET_remaining(&salt), NULL)) == NULL
2065         || (s->srp_ctx.B =
2066             BN_bin2bn(PACKET_data(&server_pub),
2067                       (int)PACKET_remaining(&server_pub), NULL)) == NULL) {
2068         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2069                  ERR_R_BN_LIB);
2070         return 0;
2071     }
2072 
2073     if (!srp_verify_server_param(s)) {
2074         /* SSLfatal() already called */
2075         return 0;
2076     }
2077 
2078     /* We must check if there is a certificate */
2079     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
2080         *pkey = X509_get0_pubkey(s->session->peer);
2081 
2082     return 1;
2083 #else
2084     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_SRP,
2085              ERR_R_INTERNAL_ERROR);
2086     return 0;
2087 #endif
2088 }
2089 
2090 static int tls_process_ske_dhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2091 {
2092 #ifndef OPENSSL_NO_DH
2093     PACKET prime, generator, pub_key;
2094     EVP_PKEY *peer_tmp = NULL;
2095 
2096     DH *dh = NULL;
2097     BIGNUM *p = NULL, *g = NULL, *bnpub_key = NULL;
2098 
2099     int check_bits = 0;
2100 
2101     if (!PACKET_get_length_prefixed_2(pkt, &prime)
2102         || !PACKET_get_length_prefixed_2(pkt, &generator)
2103         || !PACKET_get_length_prefixed_2(pkt, &pub_key)) {
2104         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2105                  SSL_R_LENGTH_MISMATCH);
2106         return 0;
2107     }
2108 
2109     peer_tmp = EVP_PKEY_new();
2110     dh = DH_new();
2111 
2112     if (peer_tmp == NULL || dh == NULL) {
2113         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2114                  ERR_R_MALLOC_FAILURE);
2115         goto err;
2116     }
2117 
2118     /* TODO(size_t): Convert these calls */
2119     p = BN_bin2bn(PACKET_data(&prime), (int)PACKET_remaining(&prime), NULL);
2120     g = BN_bin2bn(PACKET_data(&generator), (int)PACKET_remaining(&generator),
2121                   NULL);
2122     bnpub_key = BN_bin2bn(PACKET_data(&pub_key),
2123                           (int)PACKET_remaining(&pub_key), NULL);
2124     if (p == NULL || g == NULL || bnpub_key == NULL) {
2125         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2126                  ERR_R_BN_LIB);
2127         goto err;
2128     }
2129 
2130     /* test non-zero pubkey */
2131     if (BN_is_zero(bnpub_key)) {
2132         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
2133                  SSL_R_BAD_DH_VALUE);
2134         goto err;
2135     }
2136 
2137     if (!DH_set0_pqg(dh, p, NULL, g)) {
2138         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2139                  ERR_R_BN_LIB);
2140         goto err;
2141     }
2142     p = g = NULL;
2143 
2144     if (DH_check_params(dh, &check_bits) == 0 || check_bits != 0) {
2145         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_DHE,
2146                  SSL_R_BAD_DH_VALUE);
2147         goto err;
2148     }
2149 
2150     if (!DH_set0_key(dh, bnpub_key, NULL)) {
2151         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2152                  ERR_R_BN_LIB);
2153         goto err;
2154     }
2155     bnpub_key = NULL;
2156 
2157     if (!ssl_security(s, SSL_SECOP_TMP_DH, DH_security_bits(dh), 0, dh)) {
2158         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_PROCESS_SKE_DHE,
2159                  SSL_R_DH_KEY_TOO_SMALL);
2160         goto err;
2161     }
2162 
2163     if (EVP_PKEY_assign_DH(peer_tmp, dh) == 0) {
2164         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2165                  ERR_R_EVP_LIB);
2166         goto err;
2167     }
2168 
2169     s->s3->peer_tmp = peer_tmp;
2170 
2171     /*
2172      * FIXME: This makes assumptions about which ciphersuites come with
2173      * public keys. We should have a less ad-hoc way of doing this
2174      */
2175     if (s->s3->tmp.new_cipher->algorithm_auth & (SSL_aRSA | SSL_aDSS))
2176         *pkey = X509_get0_pubkey(s->session->peer);
2177     /* else anonymous DH, so no certificate or pkey. */
2178 
2179     return 1;
2180 
2181  err:
2182     BN_free(p);
2183     BN_free(g);
2184     BN_free(bnpub_key);
2185     DH_free(dh);
2186     EVP_PKEY_free(peer_tmp);
2187 
2188     return 0;
2189 #else
2190     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_DHE,
2191              ERR_R_INTERNAL_ERROR);
2192     return 0;
2193 #endif
2194 }
2195 
2196 static int tls_process_ske_ecdhe(SSL *s, PACKET *pkt, EVP_PKEY **pkey)
2197 {
2198 #ifndef OPENSSL_NO_EC
2199     PACKET encoded_pt;
2200     unsigned int curve_type, curve_id;
2201 
2202     /*
2203      * Extract elliptic curve parameters and the server's ephemeral ECDH
2204      * public key. We only support named (not generic) curves and
2205      * ECParameters in this case is just three bytes.
2206      */
2207     if (!PACKET_get_1(pkt, &curve_type) || !PACKET_get_net_2(pkt, &curve_id)) {
2208         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2209                  SSL_R_LENGTH_TOO_SHORT);
2210         return 0;
2211     }
2212     /*
2213      * Check curve is named curve type and one of our preferences, if not
2214      * server has sent an invalid curve.
2215      */
2216     if (curve_type != NAMED_CURVE_TYPE
2217             || !tls1_check_group_id(s, curve_id, 1)) {
2218         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
2219                  SSL_R_WRONG_CURVE);
2220         return 0;
2221     }
2222 
2223     if ((s->s3->peer_tmp = ssl_generate_param_group(curve_id)) == NULL) {
2224         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2225                  SSL_R_UNABLE_TO_FIND_ECDH_PARAMETERS);
2226         return 0;
2227     }
2228 
2229     if (!PACKET_get_length_prefixed_1(pkt, &encoded_pt)) {
2230         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2231                  SSL_R_LENGTH_MISMATCH);
2232         return 0;
2233     }
2234 
2235     if (!EVP_PKEY_set1_tls_encodedpoint(s->s3->peer_tmp,
2236                                         PACKET_data(&encoded_pt),
2237                                         PACKET_remaining(&encoded_pt))) {
2238         SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_TLS_PROCESS_SKE_ECDHE,
2239                  SSL_R_BAD_ECPOINT);
2240         return 0;
2241     }
2242 
2243     /*
2244      * The ECC/TLS specification does not mention the use of DSA to sign
2245      * ECParameters in the server key exchange message. We do support RSA
2246      * and ECDSA.
2247      */
2248     if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aECDSA)
2249         *pkey = X509_get0_pubkey(s->session->peer);
2250     else if (s->s3->tmp.new_cipher->algorithm_auth & SSL_aRSA)
2251         *pkey = X509_get0_pubkey(s->session->peer);
2252     /* else anonymous ECDH, so no certificate or pkey. */
2253 
2254     return 1;
2255 #else
2256     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SKE_ECDHE,
2257              ERR_R_INTERNAL_ERROR);
2258     return 0;
2259 #endif
2260 }
2261 
2262 MSG_PROCESS_RETURN tls_process_key_exchange(SSL *s, PACKET *pkt)
2263 {
2264     long alg_k;
2265     EVP_PKEY *pkey = NULL;
2266     EVP_MD_CTX *md_ctx = NULL;
2267     EVP_PKEY_CTX *pctx = NULL;
2268     PACKET save_param_start, signature;
2269 
2270     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
2271 
2272     save_param_start = *pkt;
2273 
2274 #if !defined(OPENSSL_NO_EC) || !defined(OPENSSL_NO_DH)
2275     EVP_PKEY_free(s->s3->peer_tmp);
2276     s->s3->peer_tmp = NULL;
2277 #endif
2278 
2279     if (alg_k & SSL_PSK) {
2280         if (!tls_process_ske_psk_preamble(s, pkt)) {
2281             /* SSLfatal() already called */
2282             goto err;
2283         }
2284     }
2285 
2286     /* Nothing else to do for plain PSK or RSAPSK */
2287     if (alg_k & (SSL_kPSK | SSL_kRSAPSK)) {
2288     } else if (alg_k & SSL_kSRP) {
2289         if (!tls_process_ske_srp(s, pkt, &pkey)) {
2290             /* SSLfatal() already called */
2291             goto err;
2292         }
2293     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
2294         if (!tls_process_ske_dhe(s, pkt, &pkey)) {
2295             /* SSLfatal() already called */
2296             goto err;
2297         }
2298     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
2299         if (!tls_process_ske_ecdhe(s, pkt, &pkey)) {
2300             /* SSLfatal() already called */
2301             goto err;
2302         }
2303     } else if (alg_k) {
2304         SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2305                  SSL_R_UNEXPECTED_MESSAGE);
2306         goto err;
2307     }
2308 
2309     /* if it was signed, check the signature */
2310     if (pkey != NULL) {
2311         PACKET params;
2312         int maxsig;
2313         const EVP_MD *md = NULL;
2314         unsigned char *tbs;
2315         size_t tbslen;
2316         int rv;
2317 
2318         /*
2319          * |pkt| now points to the beginning of the signature, so the difference
2320          * equals the length of the parameters.
2321          */
2322         if (!PACKET_get_sub_packet(&save_param_start, &params,
2323                                    PACKET_remaining(&save_param_start) -
2324                                    PACKET_remaining(pkt))) {
2325             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2326                      ERR_R_INTERNAL_ERROR);
2327             goto err;
2328         }
2329 
2330         if (SSL_USE_SIGALGS(s)) {
2331             unsigned int sigalg;
2332 
2333             if (!PACKET_get_net_2(pkt, &sigalg)) {
2334                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2335                          SSL_R_LENGTH_TOO_SHORT);
2336                 goto err;
2337             }
2338             if (tls12_check_peer_sigalg(s, sigalg, pkey) <=0) {
2339                 /* SSLfatal() already called */
2340                 goto err;
2341             }
2342         } else if (!tls1_set_peer_legacy_sigalg(s, pkey)) {
2343             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2344                      ERR_R_INTERNAL_ERROR);
2345             goto err;
2346         }
2347 
2348         if (!tls1_lookup_md(s->s3->tmp.peer_sigalg, &md)) {
2349             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2350                      ERR_R_INTERNAL_ERROR);
2351             goto err;
2352         }
2353 #ifdef SSL_DEBUG
2354         if (SSL_USE_SIGALGS(s))
2355             fprintf(stderr, "USING TLSv1.2 HASH %s\n",
2356                     md == NULL ? "n/a" : EVP_MD_name(md));
2357 #endif
2358 
2359         if (!PACKET_get_length_prefixed_2(pkt, &signature)
2360             || PACKET_remaining(pkt) != 0) {
2361             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2362                      SSL_R_LENGTH_MISMATCH);
2363             goto err;
2364         }
2365         maxsig = EVP_PKEY_size(pkey);
2366         if (maxsig < 0) {
2367             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2368                      ERR_R_INTERNAL_ERROR);
2369             goto err;
2370         }
2371 
2372         /*
2373          * Check signature length
2374          */
2375         if (PACKET_remaining(&signature) > (size_t)maxsig) {
2376             /* wrong packet length */
2377             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2378                    SSL_R_WRONG_SIGNATURE_LENGTH);
2379             goto err;
2380         }
2381 
2382         md_ctx = EVP_MD_CTX_new();
2383         if (md_ctx == NULL) {
2384             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2385                      ERR_R_MALLOC_FAILURE);
2386             goto err;
2387         }
2388 
2389         if (EVP_DigestVerifyInit(md_ctx, &pctx, md, NULL, pkey) <= 0) {
2390             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2391                      ERR_R_EVP_LIB);
2392             goto err;
2393         }
2394         if (SSL_USE_PSS(s)) {
2395             if (EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) <= 0
2396                 || EVP_PKEY_CTX_set_rsa_pss_saltlen(pctx,
2397                                                 RSA_PSS_SALTLEN_DIGEST) <= 0) {
2398                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2399                          SSL_F_TLS_PROCESS_KEY_EXCHANGE, ERR_R_EVP_LIB);
2400                 goto err;
2401             }
2402         }
2403         tbslen = construct_key_exchange_tbs(s, &tbs, PACKET_data(&params),
2404                                             PACKET_remaining(&params));
2405         if (tbslen == 0) {
2406             /* SSLfatal() already called */
2407             goto err;
2408         }
2409 
2410         rv = EVP_DigestVerify(md_ctx, PACKET_data(&signature),
2411                               PACKET_remaining(&signature), tbs, tbslen);
2412         OPENSSL_free(tbs);
2413         if (rv <= 0) {
2414             SSLfatal(s, SSL_AD_DECRYPT_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2415                      SSL_R_BAD_SIGNATURE);
2416             goto err;
2417         }
2418         EVP_MD_CTX_free(md_ctx);
2419         md_ctx = NULL;
2420     } else {
2421         /* aNULL, aSRP or PSK do not need public keys */
2422         if (!(s->s3->tmp.new_cipher->algorithm_auth & (SSL_aNULL | SSL_aSRP))
2423             && !(alg_k & SSL_PSK)) {
2424             /* Might be wrong key type, check it */
2425             if (ssl3_check_cert_and_algorithm(s)) {
2426                 SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2427                          SSL_R_BAD_DATA);
2428             }
2429             /* else this shouldn't happen, SSLfatal() already called */
2430             goto err;
2431         }
2432         /* still data left over */
2433         if (PACKET_remaining(pkt) != 0) {
2434             SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_KEY_EXCHANGE,
2435                      SSL_R_EXTRA_DATA_IN_MESSAGE);
2436             goto err;
2437         }
2438     }
2439 
2440     return MSG_PROCESS_CONTINUE_READING;
2441  err:
2442     EVP_MD_CTX_free(md_ctx);
2443     return MSG_PROCESS_ERROR;
2444 }
2445 
2446 MSG_PROCESS_RETURN tls_process_certificate_request(SSL *s, PACKET *pkt)
2447 {
2448     size_t i;
2449 
2450     /* Clear certificate validity flags */
2451     for (i = 0; i < SSL_PKEY_NUM; i++)
2452         s->s3->tmp.valid_flags[i] = 0;
2453 
2454     if (SSL_IS_TLS13(s)) {
2455         PACKET reqctx, extensions;
2456         RAW_EXTENSION *rawexts = NULL;
2457 
2458         if ((s->shutdown & SSL_SENT_SHUTDOWN) != 0) {
2459             /*
2460              * We already sent close_notify. This can only happen in TLSv1.3
2461              * post-handshake messages. We can't reasonably respond to this, so
2462              * we just ignore it
2463              */
2464             return MSG_PROCESS_FINISHED_READING;
2465         }
2466 
2467         /* Free and zero certificate types: it is not present in TLS 1.3 */
2468         OPENSSL_free(s->s3->tmp.ctype);
2469         s->s3->tmp.ctype = NULL;
2470         s->s3->tmp.ctype_len = 0;
2471         OPENSSL_free(s->pha_context);
2472         s->pha_context = NULL;
2473 
2474         if (!PACKET_get_length_prefixed_1(pkt, &reqctx) ||
2475             !PACKET_memdup(&reqctx, &s->pha_context, &s->pha_context_len)) {
2476             SSLfatal(s, SSL_AD_DECODE_ERROR,
2477                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2478                      SSL_R_LENGTH_MISMATCH);
2479             return MSG_PROCESS_ERROR;
2480         }
2481 
2482         if (!PACKET_get_length_prefixed_2(pkt, &extensions)) {
2483             SSLfatal(s, SSL_AD_DECODE_ERROR,
2484                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2485                      SSL_R_BAD_LENGTH);
2486             return MSG_PROCESS_ERROR;
2487         }
2488         if (!tls_collect_extensions(s, &extensions,
2489                                     SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
2490                                     &rawexts, NULL, 1)
2491             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_CERTIFICATE_REQUEST,
2492                                          rawexts, NULL, 0, 1)) {
2493             /* SSLfatal() already called */
2494             OPENSSL_free(rawexts);
2495             return MSG_PROCESS_ERROR;
2496         }
2497         OPENSSL_free(rawexts);
2498         if (!tls1_process_sigalgs(s)) {
2499             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2500                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2501                      SSL_R_BAD_LENGTH);
2502             return MSG_PROCESS_ERROR;
2503         }
2504     } else {
2505         PACKET ctypes;
2506 
2507         /* get the certificate types */
2508         if (!PACKET_get_length_prefixed_1(pkt, &ctypes)) {
2509             SSLfatal(s, SSL_AD_DECODE_ERROR,
2510                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2511                      SSL_R_LENGTH_MISMATCH);
2512             return MSG_PROCESS_ERROR;
2513         }
2514 
2515         if (!PACKET_memdup(&ctypes, &s->s3->tmp.ctype, &s->s3->tmp.ctype_len)) {
2516             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2517                      SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2518                      ERR_R_INTERNAL_ERROR);
2519             return MSG_PROCESS_ERROR;
2520         }
2521 
2522         if (SSL_USE_SIGALGS(s)) {
2523             PACKET sigalgs;
2524 
2525             if (!PACKET_get_length_prefixed_2(pkt, &sigalgs)) {
2526                 SSLfatal(s, SSL_AD_DECODE_ERROR,
2527                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2528                          SSL_R_LENGTH_MISMATCH);
2529                 return MSG_PROCESS_ERROR;
2530             }
2531 
2532             /*
2533              * Despite this being for certificates, preserve compatibility
2534              * with pre-TLS 1.3 and use the regular sigalgs field.
2535              */
2536             if (!tls1_save_sigalgs(s, &sigalgs, 0)) {
2537                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2538                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2539                          SSL_R_SIGNATURE_ALGORITHMS_ERROR);
2540                 return MSG_PROCESS_ERROR;
2541             }
2542             if (!tls1_process_sigalgs(s)) {
2543                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2544                          SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2545                          ERR_R_MALLOC_FAILURE);
2546                 return MSG_PROCESS_ERROR;
2547             }
2548         }
2549 
2550         /* get the CA RDNs */
2551         if (!parse_ca_names(s, pkt)) {
2552             /* SSLfatal() already called */
2553             return MSG_PROCESS_ERROR;
2554         }
2555     }
2556 
2557     if (PACKET_remaining(pkt) != 0) {
2558         SSLfatal(s, SSL_AD_DECODE_ERROR,
2559                  SSL_F_TLS_PROCESS_CERTIFICATE_REQUEST,
2560                  SSL_R_LENGTH_MISMATCH);
2561         return MSG_PROCESS_ERROR;
2562     }
2563 
2564     /* we should setup a certificate to return.... */
2565     s->s3->tmp.cert_req = 1;
2566 
2567     /*
2568      * In TLSv1.3 we don't prepare the client certificate yet. We wait until
2569      * after the CertificateVerify message has been received. This is because
2570      * in TLSv1.3 the CertificateRequest arrives before the Certificate message
2571      * but in TLSv1.2 it is the other way around. We want to make sure that
2572      * SSL_get_peer_certificate() returns something sensible in
2573      * client_cert_cb.
2574      */
2575     if (SSL_IS_TLS13(s) && s->post_handshake_auth != SSL_PHA_REQUESTED)
2576         return MSG_PROCESS_CONTINUE_READING;
2577 
2578     return MSG_PROCESS_CONTINUE_PROCESSING;
2579 }
2580 
2581 MSG_PROCESS_RETURN tls_process_new_session_ticket(SSL *s, PACKET *pkt)
2582 {
2583     unsigned int ticklen;
2584     unsigned long ticket_lifetime_hint, age_add = 0;
2585     unsigned int sess_len;
2586     RAW_EXTENSION *exts = NULL;
2587     PACKET nonce;
2588 
2589     PACKET_null_init(&nonce);
2590 
2591     if (!PACKET_get_net_4(pkt, &ticket_lifetime_hint)
2592         || (SSL_IS_TLS13(s)
2593             && (!PACKET_get_net_4(pkt, &age_add)
2594                 || !PACKET_get_length_prefixed_1(pkt, &nonce)))
2595         || !PACKET_get_net_2(pkt, &ticklen)
2596         || (SSL_IS_TLS13(s) ? (ticklen == 0 || PACKET_remaining(pkt) < ticklen)
2597                             : PACKET_remaining(pkt) != ticklen)) {
2598         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2599                  SSL_R_LENGTH_MISMATCH);
2600         goto err;
2601     }
2602 
2603     /*
2604      * Server is allowed to change its mind (in <=TLSv1.2) and send an empty
2605      * ticket. We already checked this TLSv1.3 case above, so it should never
2606      * be 0 here in that instance
2607      */
2608     if (ticklen == 0)
2609         return MSG_PROCESS_CONTINUE_READING;
2610 
2611     /*
2612      * Sessions must be immutable once they go into the session cache. Otherwise
2613      * we can get multi-thread problems. Therefore we don't "update" sessions,
2614      * we replace them with a duplicate. In TLSv1.3 we need to do this every
2615      * time a NewSessionTicket arrives because those messages arrive
2616      * post-handshake and the session may have already gone into the session
2617      * cache.
2618      */
2619     if (SSL_IS_TLS13(s) || s->session->session_id_length > 0) {
2620         SSL_SESSION *new_sess;
2621 
2622         /*
2623          * We reused an existing session, so we need to replace it with a new
2624          * one
2625          */
2626         if ((new_sess = ssl_session_dup(s->session, 0)) == 0) {
2627             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2628                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2629                      ERR_R_MALLOC_FAILURE);
2630             goto err;
2631         }
2632 
2633         if ((s->session_ctx->session_cache_mode & SSL_SESS_CACHE_CLIENT) != 0
2634                 && !SSL_IS_TLS13(s)) {
2635             /*
2636              * In TLSv1.2 and below the arrival of a new tickets signals that
2637              * any old ticket we were using is now out of date, so we remove the
2638              * old session from the cache. We carry on if this fails
2639              */
2640             SSL_CTX_remove_session(s->session_ctx, s->session);
2641         }
2642 
2643         SSL_SESSION_free(s->session);
2644         s->session = new_sess;
2645     }
2646 
2647     /*
2648      * Technically the cast to long here is not guaranteed by the C standard -
2649      * but we use it elsewhere, so this should be ok.
2650      */
2651     s->session->time = (long)time(NULL);
2652 
2653     OPENSSL_free(s->session->ext.tick);
2654     s->session->ext.tick = NULL;
2655     s->session->ext.ticklen = 0;
2656 
2657     s->session->ext.tick = OPENSSL_malloc(ticklen);
2658     if (s->session->ext.tick == NULL) {
2659         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2660                  ERR_R_MALLOC_FAILURE);
2661         goto err;
2662     }
2663     if (!PACKET_copy_bytes(pkt, s->session->ext.tick, ticklen)) {
2664         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2665                  SSL_R_LENGTH_MISMATCH);
2666         goto err;
2667     }
2668 
2669     s->session->ext.tick_lifetime_hint = ticket_lifetime_hint;
2670     s->session->ext.tick_age_add = age_add;
2671     s->session->ext.ticklen = ticklen;
2672 
2673     if (SSL_IS_TLS13(s)) {
2674         PACKET extpkt;
2675 
2676         if (!PACKET_as_length_prefixed_2(pkt, &extpkt)
2677                 || PACKET_remaining(pkt) != 0) {
2678             SSLfatal(s, SSL_AD_DECODE_ERROR,
2679                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2680                      SSL_R_LENGTH_MISMATCH);
2681             goto err;
2682         }
2683 
2684         if (!tls_collect_extensions(s, &extpkt,
2685                                     SSL_EXT_TLS1_3_NEW_SESSION_TICKET, &exts,
2686                                     NULL, 1)
2687                 || !tls_parse_all_extensions(s,
2688                                              SSL_EXT_TLS1_3_NEW_SESSION_TICKET,
2689                                              exts, NULL, 0, 1)) {
2690             /* SSLfatal() already called */
2691             goto err;
2692         }
2693     }
2694 
2695     /*
2696      * There are two ways to detect a resumed ticket session. One is to set
2697      * an appropriate session ID and then the server must return a match in
2698      * ServerHello. This allows the normal client session ID matching to work
2699      * and we know much earlier that the ticket has been accepted. The
2700      * other way is to set zero length session ID when the ticket is
2701      * presented and rely on the handshake to determine session resumption.
2702      * We choose the former approach because this fits in with assumptions
2703      * elsewhere in OpenSSL. The session ID is set to the SHA256 (or SHA1 is
2704      * SHA256 is disabled) hash of the ticket.
2705      */
2706     /*
2707      * TODO(size_t): we use sess_len here because EVP_Digest expects an int
2708      * but s->session->session_id_length is a size_t
2709      */
2710     if (!EVP_Digest(s->session->ext.tick, ticklen,
2711                     s->session->session_id, &sess_len,
2712                     EVP_sha256(), NULL)) {
2713         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2714                  ERR_R_EVP_LIB);
2715         goto err;
2716     }
2717     s->session->session_id_length = sess_len;
2718     s->session->not_resumable = 0;
2719 
2720     /* This is a standalone message in TLSv1.3, so there is no more to read */
2721     if (SSL_IS_TLS13(s)) {
2722         const EVP_MD *md = ssl_handshake_md(s);
2723         int hashleni = EVP_MD_size(md);
2724         size_t hashlen;
2725         static const unsigned char nonce_label[] = "resumption";
2726 
2727         /* Ensure cast to size_t is safe */
2728         if (!ossl_assert(hashleni >= 0)) {
2729             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2730                      SSL_F_TLS_PROCESS_NEW_SESSION_TICKET,
2731                      ERR_R_INTERNAL_ERROR);
2732             goto err;
2733         }
2734         hashlen = (size_t)hashleni;
2735 
2736         if (!tls13_hkdf_expand(s, md, s->resumption_master_secret,
2737                                nonce_label,
2738                                sizeof(nonce_label) - 1,
2739                                PACKET_data(&nonce),
2740                                PACKET_remaining(&nonce),
2741                                s->session->master_key,
2742                                hashlen, 1)) {
2743             /* SSLfatal() already called */
2744             goto err;
2745         }
2746         s->session->master_key_length = hashlen;
2747 
2748         OPENSSL_free(exts);
2749         ssl_update_cache(s, SSL_SESS_CACHE_CLIENT);
2750         return MSG_PROCESS_FINISHED_READING;
2751     }
2752 
2753     return MSG_PROCESS_CONTINUE_READING;
2754  err:
2755     OPENSSL_free(exts);
2756     return MSG_PROCESS_ERROR;
2757 }
2758 
2759 /*
2760  * In TLSv1.3 this is called from the extensions code, otherwise it is used to
2761  * parse a separate message. Returns 1 on success or 0 on failure
2762  */
2763 int tls_process_cert_status_body(SSL *s, PACKET *pkt)
2764 {
2765     size_t resplen;
2766     unsigned int type;
2767 
2768     if (!PACKET_get_1(pkt, &type)
2769         || type != TLSEXT_STATUSTYPE_ocsp) {
2770         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2771                  SSL_R_UNSUPPORTED_STATUS_TYPE);
2772         return 0;
2773     }
2774     if (!PACKET_get_net_3_len(pkt, &resplen)
2775         || PACKET_remaining(pkt) != resplen) {
2776         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2777                  SSL_R_LENGTH_MISMATCH);
2778         return 0;
2779     }
2780     s->ext.ocsp.resp = OPENSSL_malloc(resplen);
2781     if (s->ext.ocsp.resp == NULL) {
2782         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2783                  ERR_R_MALLOC_FAILURE);
2784         return 0;
2785     }
2786     if (!PACKET_copy_bytes(pkt, s->ext.ocsp.resp, resplen)) {
2787         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_CERT_STATUS_BODY,
2788                  SSL_R_LENGTH_MISMATCH);
2789         return 0;
2790     }
2791     s->ext.ocsp.resp_len = resplen;
2792 
2793     return 1;
2794 }
2795 
2796 
2797 MSG_PROCESS_RETURN tls_process_cert_status(SSL *s, PACKET *pkt)
2798 {
2799     if (!tls_process_cert_status_body(s, pkt)) {
2800         /* SSLfatal() already called */
2801         return MSG_PROCESS_ERROR;
2802     }
2803 
2804     return MSG_PROCESS_CONTINUE_READING;
2805 }
2806 
2807 /*
2808  * Perform miscellaneous checks and processing after we have received the
2809  * server's initial flight. In TLS1.3 this is after the Server Finished message.
2810  * In <=TLS1.2 this is after the ServerDone message. Returns 1 on success or 0
2811  * on failure.
2812  */
2813 int tls_process_initial_server_flight(SSL *s)
2814 {
2815     /*
2816      * at this point we check that we have the required stuff from
2817      * the server
2818      */
2819     if (!ssl3_check_cert_and_algorithm(s)) {
2820         /* SSLfatal() already called */
2821         return 0;
2822     }
2823 
2824     /*
2825      * Call the ocsp status callback if needed. The |ext.ocsp.resp| and
2826      * |ext.ocsp.resp_len| values will be set if we actually received a status
2827      * message, or NULL and -1 otherwise
2828      */
2829     if (s->ext.status_type != TLSEXT_STATUSTYPE_nothing
2830             && s->ctx->ext.status_cb != NULL) {
2831         int ret = s->ctx->ext.status_cb(s, s->ctx->ext.status_arg);
2832 
2833         if (ret == 0) {
2834             SSLfatal(s, SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE,
2835                      SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
2836                      SSL_R_INVALID_STATUS_RESPONSE);
2837             return 0;
2838         }
2839         if (ret < 0) {
2840             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
2841                      SSL_F_TLS_PROCESS_INITIAL_SERVER_FLIGHT,
2842                      ERR_R_MALLOC_FAILURE);
2843             return 0;
2844         }
2845     }
2846 #ifndef OPENSSL_NO_CT
2847     if (s->ct_validation_callback != NULL) {
2848         /* Note we validate the SCTs whether or not we abort on error */
2849         if (!ssl_validate_ct(s) && (s->verify_mode & SSL_VERIFY_PEER)) {
2850             /* SSLfatal() already called */
2851             return 0;
2852         }
2853     }
2854 #endif
2855 
2856     return 1;
2857 }
2858 
2859 MSG_PROCESS_RETURN tls_process_server_done(SSL *s, PACKET *pkt)
2860 {
2861     if (PACKET_remaining(pkt) > 0) {
2862         /* should contain no data */
2863         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
2864                  SSL_R_LENGTH_MISMATCH);
2865         return MSG_PROCESS_ERROR;
2866     }
2867 #ifndef OPENSSL_NO_SRP
2868     if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
2869         if (SRP_Calc_A_param(s) <= 0) {
2870             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PROCESS_SERVER_DONE,
2871                      SSL_R_SRP_A_CALC);
2872             return MSG_PROCESS_ERROR;
2873         }
2874     }
2875 #endif
2876 
2877     if (!tls_process_initial_server_flight(s)) {
2878         /* SSLfatal() already called */
2879         return MSG_PROCESS_ERROR;
2880     }
2881 
2882     return MSG_PROCESS_FINISHED_READING;
2883 }
2884 
2885 static int tls_construct_cke_psk_preamble(SSL *s, WPACKET *pkt)
2886 {
2887 #ifndef OPENSSL_NO_PSK
2888     int ret = 0;
2889     /*
2890      * The callback needs PSK_MAX_IDENTITY_LEN + 1 bytes to return a
2891      * \0-terminated identity. The last byte is for us for simulating
2892      * strnlen.
2893      */
2894     char identity[PSK_MAX_IDENTITY_LEN + 1];
2895     size_t identitylen = 0;
2896     unsigned char psk[PSK_MAX_PSK_LEN];
2897     unsigned char *tmppsk = NULL;
2898     char *tmpidentity = NULL;
2899     size_t psklen = 0;
2900 
2901     if (s->psk_client_callback == NULL) {
2902         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2903                  SSL_R_PSK_NO_CLIENT_CB);
2904         goto err;
2905     }
2906 
2907     memset(identity, 0, sizeof(identity));
2908 
2909     psklen = s->psk_client_callback(s, s->session->psk_identity_hint,
2910                                     identity, sizeof(identity) - 1,
2911                                     psk, sizeof(psk));
2912 
2913     if (psklen > PSK_MAX_PSK_LEN) {
2914         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2915                  SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE, ERR_R_INTERNAL_ERROR);
2916         goto err;
2917     } else if (psklen == 0) {
2918         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
2919                  SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2920                  SSL_R_PSK_IDENTITY_NOT_FOUND);
2921         goto err;
2922     }
2923 
2924     identitylen = strlen(identity);
2925     if (identitylen > PSK_MAX_IDENTITY_LEN) {
2926         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2927                  ERR_R_INTERNAL_ERROR);
2928         goto err;
2929     }
2930 
2931     tmppsk = OPENSSL_memdup(psk, psklen);
2932     tmpidentity = OPENSSL_strdup(identity);
2933     if (tmppsk == NULL || tmpidentity == NULL) {
2934         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2935                  ERR_R_MALLOC_FAILURE);
2936         goto err;
2937     }
2938 
2939     OPENSSL_free(s->s3->tmp.psk);
2940     s->s3->tmp.psk = tmppsk;
2941     s->s3->tmp.psklen = psklen;
2942     tmppsk = NULL;
2943     OPENSSL_free(s->session->psk_identity);
2944     s->session->psk_identity = tmpidentity;
2945     tmpidentity = NULL;
2946 
2947     if (!WPACKET_sub_memcpy_u16(pkt, identity, identitylen))  {
2948         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2949                  ERR_R_INTERNAL_ERROR);
2950         goto err;
2951     }
2952 
2953     ret = 1;
2954 
2955  err:
2956     OPENSSL_cleanse(psk, psklen);
2957     OPENSSL_cleanse(identity, sizeof(identity));
2958     OPENSSL_clear_free(tmppsk, psklen);
2959     OPENSSL_clear_free(tmpidentity, identitylen);
2960 
2961     return ret;
2962 #else
2963     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_PSK_PREAMBLE,
2964              ERR_R_INTERNAL_ERROR);
2965     return 0;
2966 #endif
2967 }
2968 
2969 static int tls_construct_cke_rsa(SSL *s, WPACKET *pkt)
2970 {
2971 #ifndef OPENSSL_NO_RSA
2972     unsigned char *encdata = NULL;
2973     EVP_PKEY *pkey = NULL;
2974     EVP_PKEY_CTX *pctx = NULL;
2975     size_t enclen;
2976     unsigned char *pms = NULL;
2977     size_t pmslen = 0;
2978 
2979     if (s->session->peer == NULL) {
2980         /*
2981          * We should always have a server certificate with SSL_kRSA.
2982          */
2983         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2984                  ERR_R_INTERNAL_ERROR);
2985         return 0;
2986     }
2987 
2988     pkey = X509_get0_pubkey(s->session->peer);
2989     if (EVP_PKEY_get0_RSA(pkey) == NULL) {
2990         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2991                  ERR_R_INTERNAL_ERROR);
2992         return 0;
2993     }
2994 
2995     pmslen = SSL_MAX_MASTER_KEY_LENGTH;
2996     pms = OPENSSL_malloc(pmslen);
2997     if (pms == NULL) {
2998         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
2999                  ERR_R_MALLOC_FAILURE);
3000         return 0;
3001     }
3002 
3003     pms[0] = s->client_version >> 8;
3004     pms[1] = s->client_version & 0xff;
3005     /* TODO(size_t): Convert this function */
3006     if (RAND_bytes(pms + 2, (int)(pmslen - 2)) <= 0) {
3007         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3008                  ERR_R_MALLOC_FAILURE);
3009         goto err;
3010     }
3011 
3012     /* Fix buf for TLS and beyond */
3013     if (s->version > SSL3_VERSION && !WPACKET_start_sub_packet_u16(pkt)) {
3014         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3015                  ERR_R_INTERNAL_ERROR);
3016         goto err;
3017     }
3018     pctx = EVP_PKEY_CTX_new(pkey, NULL);
3019     if (pctx == NULL || EVP_PKEY_encrypt_init(pctx) <= 0
3020         || EVP_PKEY_encrypt(pctx, NULL, &enclen, pms, pmslen) <= 0) {
3021         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3022                  ERR_R_EVP_LIB);
3023         goto err;
3024     }
3025     if (!WPACKET_allocate_bytes(pkt, enclen, &encdata)
3026             || EVP_PKEY_encrypt(pctx, encdata, &enclen, pms, pmslen) <= 0) {
3027         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3028                  SSL_R_BAD_RSA_ENCRYPT);
3029         goto err;
3030     }
3031     EVP_PKEY_CTX_free(pctx);
3032     pctx = NULL;
3033 
3034     /* Fix buf for TLS and beyond */
3035     if (s->version > SSL3_VERSION && !WPACKET_close(pkt)) {
3036         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3037                  ERR_R_INTERNAL_ERROR);
3038         goto err;
3039     }
3040 
3041     /* Log the premaster secret, if logging is enabled. */
3042     if (!ssl_log_rsa_client_key_exchange(s, encdata, enclen, pms, pmslen)) {
3043         /* SSLfatal() already called */
3044         goto err;
3045     }
3046 
3047     s->s3->tmp.pms = pms;
3048     s->s3->tmp.pmslen = pmslen;
3049 
3050     return 1;
3051  err:
3052     OPENSSL_clear_free(pms, pmslen);
3053     EVP_PKEY_CTX_free(pctx);
3054 
3055     return 0;
3056 #else
3057     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_RSA,
3058              ERR_R_INTERNAL_ERROR);
3059     return 0;
3060 #endif
3061 }
3062 
3063 static int tls_construct_cke_dhe(SSL *s, WPACKET *pkt)
3064 {
3065 #ifndef OPENSSL_NO_DH
3066     DH *dh_clnt = NULL;
3067     const BIGNUM *pub_key;
3068     EVP_PKEY *ckey = NULL, *skey = NULL;
3069     unsigned char *keybytes = NULL;
3070 
3071     skey = s->s3->peer_tmp;
3072     if (skey == NULL) {
3073         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3074                  ERR_R_INTERNAL_ERROR);
3075         goto err;
3076     }
3077 
3078     ckey = ssl_generate_pkey(skey);
3079     if (ckey == NULL) {
3080         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3081                  ERR_R_INTERNAL_ERROR);
3082         goto err;
3083     }
3084 
3085     dh_clnt = EVP_PKEY_get0_DH(ckey);
3086 
3087     if (dh_clnt == NULL) {
3088         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3089                  ERR_R_INTERNAL_ERROR);
3090         goto err;
3091     }
3092 
3093     if (ssl_derive(s, ckey, skey, 0) == 0) {
3094         /* SSLfatal() already called */
3095         goto err;
3096     }
3097 
3098     /* send off the data */
3099     DH_get0_key(dh_clnt, &pub_key, NULL);
3100     if (!WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(pub_key),
3101                                         &keybytes)) {
3102         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3103                  ERR_R_INTERNAL_ERROR);
3104         goto err;
3105     }
3106 
3107     BN_bn2bin(pub_key, keybytes);
3108     EVP_PKEY_free(ckey);
3109 
3110     return 1;
3111  err:
3112     EVP_PKEY_free(ckey);
3113     return 0;
3114 #else
3115     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_DHE,
3116              ERR_R_INTERNAL_ERROR);
3117     return 0;
3118 #endif
3119 }
3120 
3121 static int tls_construct_cke_ecdhe(SSL *s, WPACKET *pkt)
3122 {
3123 #ifndef OPENSSL_NO_EC
3124     unsigned char *encodedPoint = NULL;
3125     size_t encoded_pt_len = 0;
3126     EVP_PKEY *ckey = NULL, *skey = NULL;
3127     int ret = 0;
3128 
3129     skey = s->s3->peer_tmp;
3130     if (skey == NULL) {
3131         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3132                  ERR_R_INTERNAL_ERROR);
3133         return 0;
3134     }
3135 
3136     ckey = ssl_generate_pkey(skey);
3137     if (ckey == NULL) {
3138         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3139                  ERR_R_MALLOC_FAILURE);
3140         goto err;
3141     }
3142 
3143     if (ssl_derive(s, ckey, skey, 0) == 0) {
3144         /* SSLfatal() already called */
3145         goto err;
3146     }
3147 
3148     /* Generate encoding of client key */
3149     encoded_pt_len = EVP_PKEY_get1_tls_encodedpoint(ckey, &encodedPoint);
3150 
3151     if (encoded_pt_len == 0) {
3152         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3153                  ERR_R_EC_LIB);
3154         goto err;
3155     }
3156 
3157     if (!WPACKET_sub_memcpy_u8(pkt, encodedPoint, encoded_pt_len)) {
3158         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3159                  ERR_R_INTERNAL_ERROR);
3160         goto err;
3161     }
3162 
3163     ret = 1;
3164  err:
3165     OPENSSL_free(encodedPoint);
3166     EVP_PKEY_free(ckey);
3167     return ret;
3168 #else
3169     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_ECDHE,
3170              ERR_R_INTERNAL_ERROR);
3171     return 0;
3172 #endif
3173 }
3174 
3175 static int tls_construct_cke_gost(SSL *s, WPACKET *pkt)
3176 {
3177 #ifndef OPENSSL_NO_GOST
3178     /* GOST key exchange message creation */
3179     EVP_PKEY_CTX *pkey_ctx = NULL;
3180     X509 *peer_cert;
3181     size_t msglen;
3182     unsigned int md_len;
3183     unsigned char shared_ukm[32], tmp[256];
3184     EVP_MD_CTX *ukm_hash = NULL;
3185     int dgst_nid = NID_id_GostR3411_94;
3186     unsigned char *pms = NULL;
3187     size_t pmslen = 0;
3188 
3189     if ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aGOST12) != 0)
3190         dgst_nid = NID_id_GostR3411_2012_256;
3191 
3192     /*
3193      * Get server certificate PKEY and create ctx from it
3194      */
3195     peer_cert = s->session->peer;
3196     if (!peer_cert) {
3197         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3198                SSL_R_NO_GOST_CERTIFICATE_SENT_BY_PEER);
3199         return 0;
3200     }
3201 
3202     pkey_ctx = EVP_PKEY_CTX_new(X509_get0_pubkey(peer_cert), NULL);
3203     if (pkey_ctx == NULL) {
3204         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3205                  ERR_R_MALLOC_FAILURE);
3206         return 0;
3207     }
3208     /*
3209      * If we have send a certificate, and certificate key
3210      * parameters match those of server certificate, use
3211      * certificate key for key exchange
3212      */
3213 
3214     /* Otherwise, generate ephemeral key pair */
3215     pmslen = 32;
3216     pms = OPENSSL_malloc(pmslen);
3217     if (pms == NULL) {
3218         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3219                  ERR_R_MALLOC_FAILURE);
3220         goto err;
3221     }
3222 
3223     if (EVP_PKEY_encrypt_init(pkey_ctx) <= 0
3224         /* Generate session key
3225          * TODO(size_t): Convert this function
3226          */
3227         || RAND_bytes(pms, (int)pmslen) <= 0) {
3228         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3229                  ERR_R_INTERNAL_ERROR);
3230         goto err;
3231     };
3232     /*
3233      * Compute shared IV and store it in algorithm-specific context
3234      * data
3235      */
3236     ukm_hash = EVP_MD_CTX_new();
3237     if (ukm_hash == NULL
3238         || EVP_DigestInit(ukm_hash, EVP_get_digestbynid(dgst_nid)) <= 0
3239         || EVP_DigestUpdate(ukm_hash, s->s3->client_random,
3240                             SSL3_RANDOM_SIZE) <= 0
3241         || EVP_DigestUpdate(ukm_hash, s->s3->server_random,
3242                             SSL3_RANDOM_SIZE) <= 0
3243         || EVP_DigestFinal_ex(ukm_hash, shared_ukm, &md_len) <= 0) {
3244         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3245                  ERR_R_INTERNAL_ERROR);
3246         goto err;
3247     }
3248     EVP_MD_CTX_free(ukm_hash);
3249     ukm_hash = NULL;
3250     if (EVP_PKEY_CTX_ctrl(pkey_ctx, -1, EVP_PKEY_OP_ENCRYPT,
3251                           EVP_PKEY_CTRL_SET_IV, 8, shared_ukm) < 0) {
3252         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3253                  SSL_R_LIBRARY_BUG);
3254         goto err;
3255     }
3256     /* Make GOST keytransport blob message */
3257     /*
3258      * Encapsulate it into sequence
3259      */
3260     msglen = 255;
3261     if (EVP_PKEY_encrypt(pkey_ctx, tmp, &msglen, pms, pmslen) <= 0) {
3262         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3263                  SSL_R_LIBRARY_BUG);
3264         goto err;
3265     }
3266 
3267     if (!WPACKET_put_bytes_u8(pkt, V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)
3268             || (msglen >= 0x80 && !WPACKET_put_bytes_u8(pkt, 0x81))
3269             || !WPACKET_sub_memcpy_u8(pkt, tmp, msglen)) {
3270         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3271                  ERR_R_INTERNAL_ERROR);
3272         goto err;
3273     }
3274 
3275     EVP_PKEY_CTX_free(pkey_ctx);
3276     s->s3->tmp.pms = pms;
3277     s->s3->tmp.pmslen = pmslen;
3278 
3279     return 1;
3280  err:
3281     EVP_PKEY_CTX_free(pkey_ctx);
3282     OPENSSL_clear_free(pms, pmslen);
3283     EVP_MD_CTX_free(ukm_hash);
3284     return 0;
3285 #else
3286     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_GOST,
3287              ERR_R_INTERNAL_ERROR);
3288     return 0;
3289 #endif
3290 }
3291 
3292 static int tls_construct_cke_srp(SSL *s, WPACKET *pkt)
3293 {
3294 #ifndef OPENSSL_NO_SRP
3295     unsigned char *abytes = NULL;
3296 
3297     if (s->srp_ctx.A == NULL
3298             || !WPACKET_sub_allocate_bytes_u16(pkt, BN_num_bytes(s->srp_ctx.A),
3299                                                &abytes)) {
3300         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3301                  ERR_R_INTERNAL_ERROR);
3302         return 0;
3303     }
3304     BN_bn2bin(s->srp_ctx.A, abytes);
3305 
3306     OPENSSL_free(s->session->srp_username);
3307     s->session->srp_username = OPENSSL_strdup(s->srp_ctx.login);
3308     if (s->session->srp_username == NULL) {
3309         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3310                  ERR_R_MALLOC_FAILURE);
3311         return 0;
3312     }
3313 
3314     return 1;
3315 #else
3316     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_CKE_SRP,
3317              ERR_R_INTERNAL_ERROR);
3318     return 0;
3319 #endif
3320 }
3321 
3322 int tls_construct_client_key_exchange(SSL *s, WPACKET *pkt)
3323 {
3324     unsigned long alg_k;
3325 
3326     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3327 
3328     /*
3329      * All of the construct functions below call SSLfatal() if necessary so
3330      * no need to do so here.
3331      */
3332     if ((alg_k & SSL_PSK)
3333         && !tls_construct_cke_psk_preamble(s, pkt))
3334         goto err;
3335 
3336     if (alg_k & (SSL_kRSA | SSL_kRSAPSK)) {
3337         if (!tls_construct_cke_rsa(s, pkt))
3338             goto err;
3339     } else if (alg_k & (SSL_kDHE | SSL_kDHEPSK)) {
3340         if (!tls_construct_cke_dhe(s, pkt))
3341             goto err;
3342     } else if (alg_k & (SSL_kECDHE | SSL_kECDHEPSK)) {
3343         if (!tls_construct_cke_ecdhe(s, pkt))
3344             goto err;
3345     } else if (alg_k & SSL_kGOST) {
3346         if (!tls_construct_cke_gost(s, pkt))
3347             goto err;
3348     } else if (alg_k & SSL_kSRP) {
3349         if (!tls_construct_cke_srp(s, pkt))
3350             goto err;
3351     } else if (!(alg_k & SSL_kPSK)) {
3352         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3353                  SSL_F_TLS_CONSTRUCT_CLIENT_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
3354         goto err;
3355     }
3356 
3357     return 1;
3358  err:
3359     OPENSSL_clear_free(s->s3->tmp.pms, s->s3->tmp.pmslen);
3360     s->s3->tmp.pms = NULL;
3361 #ifndef OPENSSL_NO_PSK
3362     OPENSSL_clear_free(s->s3->tmp.psk, s->s3->tmp.psklen);
3363     s->s3->tmp.psk = NULL;
3364 #endif
3365     return 0;
3366 }
3367 
3368 int tls_client_key_exchange_post_work(SSL *s)
3369 {
3370     unsigned char *pms = NULL;
3371     size_t pmslen = 0;
3372 
3373     pms = s->s3->tmp.pms;
3374     pmslen = s->s3->tmp.pmslen;
3375 
3376 #ifndef OPENSSL_NO_SRP
3377     /* Check for SRP */
3378     if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kSRP) {
3379         if (!srp_generate_client_master_secret(s)) {
3380             /* SSLfatal() already called */
3381             goto err;
3382         }
3383         return 1;
3384     }
3385 #endif
3386 
3387     if (pms == NULL && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
3388         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3389                  SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK, ERR_R_MALLOC_FAILURE);
3390         goto err;
3391     }
3392     if (!ssl_generate_master_secret(s, pms, pmslen, 1)) {
3393         /* SSLfatal() already called */
3394         /* ssl_generate_master_secret frees the pms even on error */
3395         pms = NULL;
3396         pmslen = 0;
3397         goto err;
3398     }
3399     pms = NULL;
3400     pmslen = 0;
3401 
3402 #ifndef OPENSSL_NO_SCTP
3403     if (SSL_IS_DTLS(s)) {
3404         unsigned char sctpauthkey[64];
3405         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
3406         size_t labellen;
3407 
3408         /*
3409          * Add new shared key for SCTP-Auth, will be ignored if no SCTP
3410          * used.
3411          */
3412         memcpy(labelbuffer, DTLS1_SCTP_AUTH_LABEL,
3413                sizeof(DTLS1_SCTP_AUTH_LABEL));
3414 
3415         /* Don't include the terminating zero. */
3416         labellen = sizeof(labelbuffer) - 1;
3417         if (s->mode & SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG)
3418             labellen += 1;
3419 
3420         if (SSL_export_keying_material(s, sctpauthkey,
3421                                        sizeof(sctpauthkey), labelbuffer,
3422                                        labellen, NULL, 0, 0) <= 0) {
3423             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3424                      SSL_F_TLS_CLIENT_KEY_EXCHANGE_POST_WORK,
3425                      ERR_R_INTERNAL_ERROR);
3426             goto err;
3427         }
3428 
3429         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
3430                  sizeof(sctpauthkey), sctpauthkey);
3431     }
3432 #endif
3433 
3434     return 1;
3435  err:
3436     OPENSSL_clear_free(pms, pmslen);
3437     s->s3->tmp.pms = NULL;
3438     return 0;
3439 }
3440 
3441 /*
3442  * Check a certificate can be used for client authentication. Currently check
3443  * cert exists, if we have a suitable digest for TLS 1.2 if static DH client
3444  * certificates can be used and optionally checks suitability for Suite B.
3445  */
3446 static int ssl3_check_client_certificate(SSL *s)
3447 {
3448     /* If no suitable signature algorithm can't use certificate */
3449     if (!tls_choose_sigalg(s, 0) || s->s3->tmp.sigalg == NULL)
3450         return 0;
3451     /*
3452      * If strict mode check suitability of chain before using it. This also
3453      * adjusts suite B digest if necessary.
3454      */
3455     if (s->cert->cert_flags & SSL_CERT_FLAGS_CHECK_TLS_STRICT &&
3456         !tls1_check_chain(s, NULL, NULL, NULL, -2))
3457         return 0;
3458     return 1;
3459 }
3460 
3461 WORK_STATE tls_prepare_client_certificate(SSL *s, WORK_STATE wst)
3462 {
3463     X509 *x509 = NULL;
3464     EVP_PKEY *pkey = NULL;
3465     int i;
3466 
3467     if (wst == WORK_MORE_A) {
3468         /* Let cert callback update client certificates if required */
3469         if (s->cert->cert_cb) {
3470             i = s->cert->cert_cb(s, s->cert->cert_cb_arg);
3471             if (i < 0) {
3472                 s->rwstate = SSL_X509_LOOKUP;
3473                 return WORK_MORE_A;
3474             }
3475             if (i == 0) {
3476                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3477                          SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3478                          SSL_R_CALLBACK_FAILED);
3479                 return WORK_ERROR;
3480             }
3481             s->rwstate = SSL_NOTHING;
3482         }
3483         if (ssl3_check_client_certificate(s)) {
3484             if (s->post_handshake_auth == SSL_PHA_REQUESTED) {
3485                 return WORK_FINISHED_STOP;
3486             }
3487             return WORK_FINISHED_CONTINUE;
3488         }
3489 
3490         /* Fall through to WORK_MORE_B */
3491         wst = WORK_MORE_B;
3492     }
3493 
3494     /* We need to get a client cert */
3495     if (wst == WORK_MORE_B) {
3496         /*
3497          * If we get an error, we need to ssl->rwstate=SSL_X509_LOOKUP;
3498          * return(-1); We then get retied later
3499          */
3500         i = ssl_do_client_cert_cb(s, &x509, &pkey);
3501         if (i < 0) {
3502             s->rwstate = SSL_X509_LOOKUP;
3503             return WORK_MORE_B;
3504         }
3505         s->rwstate = SSL_NOTHING;
3506         if ((i == 1) && (pkey != NULL) && (x509 != NULL)) {
3507             if (!SSL_use_certificate(s, x509) || !SSL_use_PrivateKey(s, pkey))
3508                 i = 0;
3509         } else if (i == 1) {
3510             i = 0;
3511             SSLerr(SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3512                    SSL_R_BAD_DATA_RETURNED_BY_CALLBACK);
3513         }
3514 
3515         X509_free(x509);
3516         EVP_PKEY_free(pkey);
3517         if (i && !ssl3_check_client_certificate(s))
3518             i = 0;
3519         if (i == 0) {
3520             if (s->version == SSL3_VERSION) {
3521                 s->s3->tmp.cert_req = 0;
3522                 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_CERTIFICATE);
3523                 return WORK_FINISHED_CONTINUE;
3524             } else {
3525                 s->s3->tmp.cert_req = 2;
3526                 if (!ssl3_digest_cached_records(s, 0)) {
3527                     /* SSLfatal() already called */
3528                     return WORK_ERROR;
3529                 }
3530             }
3531         }
3532 
3533         if (s->post_handshake_auth == SSL_PHA_REQUESTED)
3534             return WORK_FINISHED_STOP;
3535         return WORK_FINISHED_CONTINUE;
3536     }
3537 
3538     /* Shouldn't ever get here */
3539     SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_PREPARE_CLIENT_CERTIFICATE,
3540              ERR_R_INTERNAL_ERROR);
3541     return WORK_ERROR;
3542 }
3543 
3544 int tls_construct_client_certificate(SSL *s, WPACKET *pkt)
3545 {
3546     if (SSL_IS_TLS13(s)) {
3547         if (s->pha_context == NULL) {
3548             /* no context available, add 0-length context */
3549             if (!WPACKET_put_bytes_u8(pkt, 0)) {
3550                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3551                          SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
3552                 return 0;
3553             }
3554         } else if (!WPACKET_sub_memcpy_u8(pkt, s->pha_context, s->pha_context_len)) {
3555             SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3556                      SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE, ERR_R_INTERNAL_ERROR);
3557             return 0;
3558         }
3559     }
3560     if (!ssl3_output_cert_chain(s, pkt,
3561                                 (s->s3->tmp.cert_req == 2) ? NULL
3562                                                            : s->cert->key)) {
3563         /* SSLfatal() already called */
3564         return 0;
3565     }
3566 
3567     if (SSL_IS_TLS13(s)
3568             && SSL_IS_FIRST_HANDSHAKE(s)
3569             && (!s->method->ssl3_enc->change_cipher_state(s,
3570                     SSL3_CC_HANDSHAKE | SSL3_CHANGE_CIPHER_CLIENT_WRITE))) {
3571         /*
3572          * This is a fatal error, which leaves enc_write_ctx in an inconsistent
3573          * state and thus ssl3_send_alert may crash.
3574          */
3575         SSLfatal(s, SSL_AD_NO_ALERT, SSL_F_TLS_CONSTRUCT_CLIENT_CERTIFICATE,
3576                  SSL_R_CANNOT_CHANGE_CIPHER);
3577         return 0;
3578     }
3579 
3580     return 1;
3581 }
3582 
3583 int ssl3_check_cert_and_algorithm(SSL *s)
3584 {
3585     const SSL_CERT_LOOKUP *clu;
3586     size_t idx;
3587     long alg_k, alg_a;
3588 
3589     alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
3590     alg_a = s->s3->tmp.new_cipher->algorithm_auth;
3591 
3592     /* we don't have a certificate */
3593     if (!(alg_a & SSL_aCERT))
3594         return 1;
3595 
3596     /* This is the passed certificate */
3597     clu = ssl_cert_lookup_by_pkey(X509_get0_pubkey(s->session->peer), &idx);
3598 
3599     /* Check certificate is recognised and suitable for cipher */
3600     if (clu == NULL || (alg_a & clu->amask) == 0) {
3601         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3602                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3603                  SSL_R_MISSING_SIGNING_CERT);
3604         return 0;
3605     }
3606 
3607 #ifndef OPENSSL_NO_EC
3608     if (clu->amask & SSL_aECDSA) {
3609         if (ssl_check_srvr_ecc_cert_and_alg(s->session->peer, s))
3610             return 1;
3611         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3612                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM, SSL_R_BAD_ECC_CERT);
3613         return 0;
3614     }
3615 #endif
3616 #ifndef OPENSSL_NO_RSA
3617     if (alg_k & (SSL_kRSA | SSL_kRSAPSK) && idx != SSL_PKEY_RSA) {
3618         SSLfatal(s, SSL_AD_HANDSHAKE_FAILURE,
3619                  SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3620                  SSL_R_MISSING_RSA_ENCRYPTING_CERT);
3621         return 0;
3622     }
3623 #endif
3624 #ifndef OPENSSL_NO_DH
3625     if ((alg_k & SSL_kDHE) && (s->s3->peer_tmp == NULL)) {
3626         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL3_CHECK_CERT_AND_ALGORITHM,
3627                  ERR_R_INTERNAL_ERROR);
3628         return 0;
3629     }
3630 #endif
3631 
3632     return 1;
3633 }
3634 
3635 #ifndef OPENSSL_NO_NEXTPROTONEG
3636 int tls_construct_next_proto(SSL *s, WPACKET *pkt)
3637 {
3638     size_t len, padding_len;
3639     unsigned char *padding = NULL;
3640 
3641     len = s->ext.npn_len;
3642     padding_len = 32 - ((len + 2) % 32);
3643 
3644     if (!WPACKET_sub_memcpy_u8(pkt, s->ext.npn, len)
3645             || !WPACKET_sub_allocate_bytes_u8(pkt, padding_len, &padding)) {
3646         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_TLS_CONSTRUCT_NEXT_PROTO,
3647                  ERR_R_INTERNAL_ERROR);
3648         return 0;
3649     }
3650 
3651     memset(padding, 0, padding_len);
3652 
3653     return 1;
3654 }
3655 #endif
3656 
3657 MSG_PROCESS_RETURN tls_process_hello_req(SSL *s, PACKET *pkt)
3658 {
3659     if (PACKET_remaining(pkt) > 0) {
3660         /* should contain no data */
3661         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_HELLO_REQ,
3662                  SSL_R_LENGTH_MISMATCH);
3663         return MSG_PROCESS_ERROR;
3664     }
3665 
3666     if ((s->options & SSL_OP_NO_RENEGOTIATION)) {
3667         ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
3668         return MSG_PROCESS_FINISHED_READING;
3669     }
3670 
3671     /*
3672      * This is a historical discrepancy (not in the RFC) maintained for
3673      * compatibility reasons. If a TLS client receives a HelloRequest it will
3674      * attempt an abbreviated handshake. However if a DTLS client receives a
3675      * HelloRequest it will do a full handshake. Either behaviour is reasonable
3676      * but doing one for TLS and another for DTLS is odd.
3677      */
3678     if (SSL_IS_DTLS(s))
3679         SSL_renegotiate(s);
3680     else
3681         SSL_renegotiate_abbreviated(s);
3682 
3683     return MSG_PROCESS_FINISHED_READING;
3684 }
3685 
3686 static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
3687 {
3688     PACKET extensions;
3689     RAW_EXTENSION *rawexts = NULL;
3690 
3691     if (!PACKET_as_length_prefixed_2(pkt, &extensions)
3692             || PACKET_remaining(pkt) != 0) {
3693         SSLfatal(s, SSL_AD_DECODE_ERROR, SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS,
3694                  SSL_R_LENGTH_MISMATCH);
3695         goto err;
3696     }
3697 
3698     if (!tls_collect_extensions(s, &extensions,
3699                                 SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS, &rawexts,
3700                                 NULL, 1)
3701             || !tls_parse_all_extensions(s, SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS,
3702                                          rawexts, NULL, 0, 1)) {
3703         /* SSLfatal() already called */
3704         goto err;
3705     }
3706 
3707     OPENSSL_free(rawexts);
3708     return MSG_PROCESS_CONTINUE_READING;
3709 
3710  err:
3711     OPENSSL_free(rawexts);
3712     return MSG_PROCESS_ERROR;
3713 }
3714 
3715 int ssl_do_client_cert_cb(SSL *s, X509 **px509, EVP_PKEY **ppkey)
3716 {
3717     int i = 0;
3718 #ifndef OPENSSL_NO_ENGINE
3719     if (s->ctx->client_cert_engine) {
3720         i = ENGINE_load_ssl_client_cert(s->ctx->client_cert_engine, s,
3721                                         SSL_get_client_CA_list(s),
3722                                         px509, ppkey, NULL, NULL, NULL);
3723         if (i != 0)
3724             return i;
3725     }
3726 #endif
3727     if (s->ctx->client_cert_cb)
3728         i = s->ctx->client_cert_cb(s, px509, ppkey);
3729     return i;
3730 }
3731 
3732 int ssl_cipher_list_to_bytes(SSL *s, STACK_OF(SSL_CIPHER) *sk, WPACKET *pkt)
3733 {
3734     int i;
3735     size_t totlen = 0, len, maxlen, maxverok = 0;
3736     int empty_reneg_info_scsv = !s->renegotiate;
3737 
3738     /* Set disabled masks for this session */
3739     if (!ssl_set_client_disabled(s)) {
3740         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3741                  SSL_R_NO_PROTOCOLS_AVAILABLE);
3742         return 0;
3743     }
3744 
3745     if (sk == NULL) {
3746         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3747                  ERR_R_INTERNAL_ERROR);
3748         return 0;
3749     }
3750 
3751 #ifdef OPENSSL_MAX_TLS1_2_CIPHER_LENGTH
3752 # if OPENSSL_MAX_TLS1_2_CIPHER_LENGTH < 6
3753 #  error Max cipher length too short
3754 # endif
3755     /*
3756      * Some servers hang if client hello > 256 bytes as hack workaround
3757      * chop number of supported ciphers to keep it well below this if we
3758      * use TLS v1.2
3759      */
3760     if (TLS1_get_version(s) >= TLS1_2_VERSION)
3761         maxlen = OPENSSL_MAX_TLS1_2_CIPHER_LENGTH & ~1;
3762     else
3763 #endif
3764         /* Maximum length that can be stored in 2 bytes. Length must be even */
3765         maxlen = 0xfffe;
3766 
3767     if (empty_reneg_info_scsv)
3768         maxlen -= 2;
3769     if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV)
3770         maxlen -= 2;
3771 
3772     for (i = 0; i < sk_SSL_CIPHER_num(sk) && totlen < maxlen; i++) {
3773         const SSL_CIPHER *c;
3774 
3775         c = sk_SSL_CIPHER_value(sk, i);
3776         /* Skip disabled ciphers */
3777         if (ssl_cipher_disabled(s, c, SSL_SECOP_CIPHER_SUPPORTED, 0))
3778             continue;
3779 
3780         if (!s->method->put_cipher_by_char(c, pkt, &len)) {
3781             SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3782                      ERR_R_INTERNAL_ERROR);
3783             return 0;
3784         }
3785 
3786         /* Sanity check that the maximum version we offer has ciphers enabled */
3787         if (!maxverok) {
3788             if (SSL_IS_DTLS(s)) {
3789                 if (DTLS_VERSION_GE(c->max_dtls, s->s3->tmp.max_ver)
3790                         && DTLS_VERSION_LE(c->min_dtls, s->s3->tmp.max_ver))
3791                     maxverok = 1;
3792             } else {
3793                 if (c->max_tls >= s->s3->tmp.max_ver
3794                         && c->min_tls <= s->s3->tmp.max_ver)
3795                     maxverok = 1;
3796             }
3797         }
3798 
3799         totlen += len;
3800     }
3801 
3802     if (totlen == 0 || !maxverok) {
3803         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_SSL_CIPHER_LIST_TO_BYTES,
3804                  SSL_R_NO_CIPHERS_AVAILABLE);
3805 
3806         if (!maxverok)
3807             ERR_add_error_data(1, "No ciphers enabled for max supported "
3808                                   "SSL/TLS version");
3809 
3810         return 0;
3811     }
3812 
3813     if (totlen != 0) {
3814         if (empty_reneg_info_scsv) {
3815             static SSL_CIPHER scsv = {
3816                 0, NULL, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
3817             };
3818             if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
3819                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3820                          SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
3821                 return 0;
3822             }
3823         }
3824         if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV) {
3825             static SSL_CIPHER scsv = {
3826                 0, NULL, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
3827             };
3828             if (!s->method->put_cipher_by_char(&scsv, pkt, &len)) {
3829                 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3830                          SSL_F_SSL_CIPHER_LIST_TO_BYTES, ERR_R_INTERNAL_ERROR);
3831                 return 0;
3832             }
3833         }
3834     }
3835 
3836     return 1;
3837 }
3838 
3839 int tls_construct_end_of_early_data(SSL *s, WPACKET *pkt)
3840 {
3841     if (s->early_data_state != SSL_EARLY_DATA_WRITE_RETRY
3842             && s->early_data_state != SSL_EARLY_DATA_FINISHED_WRITING) {
3843         SSLfatal(s, SSL_AD_INTERNAL_ERROR,
3844                  SSL_F_TLS_CONSTRUCT_END_OF_EARLY_DATA,
3845                  ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
3846         return 0;
3847     }
3848 
3849     s->early_data_state = SSL_EARLY_DATA_FINISHED_WRITING;
3850     return 1;
3851 }
3852