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[openssl.git] / ssl / d1_srvr.c
1 /* ssl/d1_srvr.c */
2 /* 
3  * DTLS implementation written by Nagendra Modadugu
4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
5  */
6 /* ====================================================================
7  * Copyright (c) 1999-2007 The OpenSSL Project.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer. 
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  *
21  * 3. All advertising materials mentioning features or use of this
22  *    software must display the following acknowledgment:
23  *    "This product includes software developed by the OpenSSL Project
24  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25  *
26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27  *    endorse or promote products derived from this software without
28  *    prior written permission. For written permission, please contact
29  *    openssl-core@OpenSSL.org.
30  *
31  * 5. Products derived from this software may not be called "OpenSSL"
32  *    nor may "OpenSSL" appear in their names without prior written
33  *    permission of the OpenSSL Project.
34  *
35  * 6. Redistributions of any form whatsoever must retain the following
36  *    acknowledgment:
37  *    "This product includes software developed by the OpenSSL Project
38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51  * OF THE POSSIBILITY OF SUCH DAMAGE.
52  * ====================================================================
53  *
54  * This product includes cryptographic software written by Eric Young
55  * (eay@cryptsoft.com).  This product includes software written by Tim
56  * Hudson (tjh@cryptsoft.com).
57  *
58  */
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60  * All rights reserved.
61  *
62  * This package is an SSL implementation written
63  * by Eric Young (eay@cryptsoft.com).
64  * The implementation was written so as to conform with Netscapes SSL.
65  * 
66  * This library is free for commercial and non-commercial use as long as
67  * the following conditions are aheared to.  The following conditions
68  * apply to all code found in this distribution, be it the RC4, RSA,
69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
70  * included with this distribution is covered by the same copyright terms
71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
72  * 
73  * Copyright remains Eric Young's, and as such any Copyright notices in
74  * the code are not to be removed.
75  * If this package is used in a product, Eric Young should be given attribution
76  * as the author of the parts of the library used.
77  * This can be in the form of a textual message at program startup or
78  * in documentation (online or textual) provided with the package.
79  * 
80  * Redistribution and use in source and binary forms, with or without
81  * modification, are permitted provided that the following conditions
82  * are met:
83  * 1. Redistributions of source code must retain the copyright
84  *    notice, this list of conditions and the following disclaimer.
85  * 2. Redistributions in binary form must reproduce the above copyright
86  *    notice, this list of conditions and the following disclaimer in the
87  *    documentation and/or other materials provided with the distribution.
88  * 3. All advertising materials mentioning features or use of this software
89  *    must display the following acknowledgement:
90  *    "This product includes cryptographic software written by
91  *     Eric Young (eay@cryptsoft.com)"
92  *    The word 'cryptographic' can be left out if the rouines from the library
93  *    being used are not cryptographic related :-).
94  * 4. If you include any Windows specific code (or a derivative thereof) from 
95  *    the apps directory (application code) you must include an acknowledgement:
96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
97  * 
98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
108  * SUCH DAMAGE.
109  * 
110  * The licence and distribution terms for any publically available version or
111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
112  * copied and put under another distribution licence
113  * [including the GNU Public Licence.]
114  */
115
116 #include <stdio.h>
117 #include "ssl_locl.h"
118 #include <openssl/buffer.h>
119 #include <openssl/rand.h>
120 #include <openssl/objects.h>
121 #include <openssl/evp.h>
122 #include <openssl/x509.h>
123 #include <openssl/md5.h>
124 #include <openssl/bn.h>
125 #ifndef OPENSSL_NO_DH
126 #include <openssl/dh.h>
127 #endif
128
129 static const SSL_METHOD *dtls1_get_server_method(int ver);
130 static int dtls1_send_hello_verify_request(SSL *s);
131
132 static const SSL_METHOD *dtls1_get_server_method(int ver)
133         {
134         if (ver == DTLS1_VERSION)
135                 return(DTLSv1_server_method());
136         else if (ver == DTLS1_2_VERSION)
137                 return(DTLSv1_2_server_method());
138         else
139                 return(NULL);
140         }
141
142 IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
143                         DTLSv1_server_method,
144                         dtls1_accept,
145                         ssl_undefined_function,
146                         dtls1_get_server_method,
147                         DTLSv1_enc_data)
148
149 IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
150                         DTLSv1_2_server_method,
151                         dtls1_accept,
152                         ssl_undefined_function,
153                         dtls1_get_server_method,
154                         DTLSv1_2_enc_data)
155
156 IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
157                         DTLS_server_method,
158                         dtls1_accept,
159                         ssl_undefined_function,
160                         dtls1_get_server_method,
161                         DTLSv1_2_enc_data)
162
163 int dtls1_accept(SSL *s)
164         {
165         BUF_MEM *buf;
166         unsigned long Time=(unsigned long)time(NULL);
167         void (*cb)(const SSL *ssl,int type,int val)=NULL;
168         unsigned long alg_k;
169         int ret= -1;
170         int new_state,state,skip=0;
171         int listen;
172 #ifndef OPENSSL_NO_SCTP
173         unsigned char sctpauthkey[64];
174         char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
175 #endif
176
177         RAND_add(&Time,sizeof(Time),0);
178         ERR_clear_error();
179         clear_sys_error();
180
181         if (s->info_callback != NULL)
182                 cb=s->info_callback;
183         else if (s->ctx->info_callback != NULL)
184                 cb=s->ctx->info_callback;
185         
186         listen = s->d1->listen;
187
188         /* init things to blank */
189         s->in_handshake++;
190         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
191
192         s->d1->listen = listen;
193 #ifndef OPENSSL_NO_SCTP
194         /* Notify SCTP BIO socket to enter handshake
195          * mode and prevent stream identifier other
196          * than 0. Will be ignored if no SCTP is used.
197          */
198         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
199 #endif
200
201         if (s->cert == NULL)
202                 {
203                 SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
204                 return(-1);
205                 }
206
207 #ifndef OPENSSL_NO_HEARTBEATS
208         /* If we're awaiting a HeartbeatResponse, pretend we
209          * already got and don't await it anymore, because
210          * Heartbeats don't make sense during handshakes anyway.
211          */
212         if (s->tlsext_hb_pending)
213                 {
214                 dtls1_stop_timer(s);
215                 s->tlsext_hb_pending = 0;
216                 s->tlsext_hb_seq++;
217                 }
218 #endif
219
220         for (;;)
221                 {
222                 state=s->state;
223
224                 switch (s->state)
225                         {
226                 case SSL_ST_RENEGOTIATE:
227                         s->renegotiate=1;
228                         /* s->state=SSL_ST_ACCEPT; */
229
230                 case SSL_ST_BEFORE:
231                 case SSL_ST_ACCEPT:
232                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
233                 case SSL_ST_OK|SSL_ST_ACCEPT:
234
235                         s->server=1;
236                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
237
238                         if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00))
239                                 {
240                                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
241                                 return -1;
242                                 }
243                         s->type=SSL_ST_ACCEPT;
244
245                         if (s->init_buf == NULL)
246                                 {
247                                 if ((buf=BUF_MEM_new()) == NULL)
248                                         {
249                                         ret= -1;
250                                         goto end;
251                                         }
252                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
253                                         {
254                                         ret= -1;
255                                         goto end;
256                                         }
257                                 s->init_buf=buf;
258                                 }
259
260                         if (!ssl3_setup_buffers(s))
261                                 {
262                                 ret= -1;
263                                 goto end;
264                                 }
265
266                         s->init_num=0;
267
268                         if (s->state != SSL_ST_RENEGOTIATE)
269                                 {
270                                 /* Ok, we now need to push on a buffering BIO so that
271                                  * the output is sent in a way that TCP likes :-)
272                                  * ...but not with SCTP :-)
273                                  */
274 #ifndef OPENSSL_NO_SCTP
275                                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
276 #endif
277                                         if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
278
279                                 ssl3_init_finished_mac(s);
280                                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
281                                 s->ctx->stats.sess_accept++;
282                                 }
283                         else
284                                 {
285                                 /* s->state == SSL_ST_RENEGOTIATE,
286                                  * we will just send a HelloRequest */
287                                 s->ctx->stats.sess_accept_renegotiate++;
288                                 s->state=SSL3_ST_SW_HELLO_REQ_A;
289                                 }
290
291                         break;
292
293                 case SSL3_ST_SW_HELLO_REQ_A:
294                 case SSL3_ST_SW_HELLO_REQ_B:
295
296                         s->shutdown=0;
297                         dtls1_clear_record_buffer(s);
298                         dtls1_start_timer(s);
299                         ret=ssl3_send_hello_request(s);
300                         if (ret <= 0) goto end;
301                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
302                         s->state=SSL3_ST_SW_FLUSH;
303                         s->init_num=0;
304
305                         ssl3_init_finished_mac(s);
306                         break;
307
308                 case SSL3_ST_SW_HELLO_REQ_C:
309                         s->state=SSL_ST_OK;
310                         break;
311
312                 case SSL3_ST_SR_CLNT_HELLO_A:
313                 case SSL3_ST_SR_CLNT_HELLO_B:
314                 case SSL3_ST_SR_CLNT_HELLO_C:
315
316                         s->shutdown=0;
317                         ret=ssl3_get_client_hello(s);
318                         if (ret <= 0) goto end;
319                         dtls1_stop_timer(s);
320
321                         if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
322                                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
323                         else
324                                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
325
326                         s->init_num=0;
327
328                         /* Reflect ClientHello sequence to remain stateless while listening */
329                         if (listen)
330                                 {
331                                 memcpy(s->s3->write_sequence, s->s3->read_sequence, sizeof(s->s3->write_sequence));
332                                 }
333
334                         /* If we're just listening, stop here */
335                         if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A)
336                                 {
337                                 ret = 2;
338                                 s->d1->listen = 0;
339                                 /* Set expected sequence numbers
340                                  * to continue the handshake.
341                                  */
342                                 s->d1->handshake_read_seq = 2;
343                                 s->d1->handshake_write_seq = 1;
344                                 s->d1->next_handshake_write_seq = 1;
345                                 goto end;
346                                 }
347                         
348                         break;
349                         
350                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
351                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
352
353                         ret = dtls1_send_hello_verify_request(s);
354                         if ( ret <= 0) goto end;
355                         s->state=SSL3_ST_SW_FLUSH;
356                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
357
358                         /* HelloVerifyRequest resets Finished MAC */
359                         if (s->version != DTLS1_BAD_VER)
360                                 ssl3_init_finished_mac(s);
361                         break;
362                         
363 #ifndef OPENSSL_NO_SCTP
364                 case DTLS1_SCTP_ST_SR_READ_SOCK:
365                         
366                         if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))                
367                                 {
368                                 s->s3->in_read_app_data=2;
369                                 s->rwstate=SSL_READING;
370                                 BIO_clear_retry_flags(SSL_get_rbio(s));
371                                 BIO_set_retry_read(SSL_get_rbio(s));
372                                 ret = -1;
373                                 goto end;
374                                 }
375                         
376                         s->state=SSL3_ST_SR_FINISHED_A;
377                         break;
378                         
379                 case DTLS1_SCTP_ST_SW_WRITE_SOCK:
380                         ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
381                         if (ret < 0) goto end;
382                         
383                         if (ret == 0)
384                                 {
385                                 if (s->d1->next_state != SSL_ST_OK)
386                                         {
387                                         s->s3->in_read_app_data=2;
388                                         s->rwstate=SSL_READING;
389                                         BIO_clear_retry_flags(SSL_get_rbio(s));
390                                         BIO_set_retry_read(SSL_get_rbio(s));
391                                         ret = -1;
392                                         goto end;
393                                         }
394                                 }
395
396                         s->state=s->d1->next_state;
397                         break;
398 #endif
399
400                 case SSL3_ST_SW_SRVR_HELLO_A:
401                 case SSL3_ST_SW_SRVR_HELLO_B:
402                         s->renegotiate = 2;
403                         dtls1_start_timer(s);
404                         ret=ssl3_send_server_hello(s);
405                         if (ret <= 0) goto end;
406
407                         if (s->hit)
408                                 {
409 #ifndef OPENSSL_NO_SCTP
410                                 /* Add new shared key for SCTP-Auth,
411                                  * will be ignored if no SCTP used.
412                                  */
413                                 snprintf((char*) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
414                                          DTLS1_SCTP_AUTH_LABEL);
415
416                                 SSL_export_keying_material(s, sctpauthkey,
417                                                            sizeof(sctpauthkey), labelbuffer,
418                                                            sizeof(labelbuffer), NULL, 0, 0);
419                                 
420                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
421                          sizeof(sctpauthkey), sctpauthkey);
422 #endif
423 #ifndef OPENSSL_NO_TLSEXT
424                                 if (s->tlsext_ticket_expected)
425                                         s->state=SSL3_ST_SW_SESSION_TICKET_A;
426                                 else
427                                         s->state=SSL3_ST_SW_CHANGE_A;
428 #else
429                                 s->state=SSL3_ST_SW_CHANGE_A;
430 #endif
431                                 }
432                         else
433                                 s->state=SSL3_ST_SW_CERT_A;
434                         s->init_num=0;
435                         break;
436
437                 case SSL3_ST_SW_CERT_A:
438                 case SSL3_ST_SW_CERT_B:
439                         /* Check if it is anon DH or normal PSK */
440                         if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
441                                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
442                                 {
443                                 dtls1_start_timer(s);
444                                 ret=ssl3_send_server_certificate(s);
445                                 if (ret <= 0) goto end;
446 #ifndef OPENSSL_NO_TLSEXT
447                                 if (s->tlsext_status_expected)
448                                         s->state=SSL3_ST_SW_CERT_STATUS_A;
449                                 else
450                                         s->state=SSL3_ST_SW_KEY_EXCH_A;
451                                 }
452                         else
453                                 {
454                                 skip = 1;
455                                 s->state=SSL3_ST_SW_KEY_EXCH_A;
456                                 }
457 #else
458                                 }
459                         else
460                                 skip=1;
461
462                         s->state=SSL3_ST_SW_KEY_EXCH_A;
463 #endif
464                         s->init_num=0;
465                         break;
466
467                 case SSL3_ST_SW_KEY_EXCH_A:
468                 case SSL3_ST_SW_KEY_EXCH_B:
469                         alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
470
471                         /* clear this, it may get reset by
472                          * send_server_key_exchange */
473                         if ((s->options & SSL_OP_EPHEMERAL_RSA)
474 #ifndef OPENSSL_NO_KRB5
475                                 && !(alg_k & SSL_kKRB5)
476 #endif /* OPENSSL_NO_KRB5 */
477                                 )
478                                 /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key
479                                  * even when forbidden by protocol specs
480                                  * (handshake may fail as clients are not required to
481                                  * be able to handle this) */
482                                 s->s3->tmp.use_rsa_tmp=1;
483                         else
484                                 s->s3->tmp.use_rsa_tmp=0;
485
486                         /* only send if a DH key exchange or
487                          * RSA but we have a sign only certificate */
488                         if (s->s3->tmp.use_rsa_tmp
489                         /* PSK: send ServerKeyExchange if PSK identity
490                          * hint if provided */
491 #ifndef OPENSSL_NO_PSK
492                             || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
493 #endif
494                             || (alg_k & (SSL_kEDH|SSL_kDHr|SSL_kDHd))
495                             || (alg_k & SSL_kEECDH)
496                             || ((alg_k & SSL_kRSA)
497                                 && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
498                                     || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
499                                         && EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
500                                         )
501                                     )
502                                 )
503                             )
504                                 {
505                                 dtls1_start_timer(s);
506                                 ret=ssl3_send_server_key_exchange(s);
507                                 if (ret <= 0) goto end;
508                                 }
509                         else
510                                 skip=1;
511
512                         s->state=SSL3_ST_SW_CERT_REQ_A;
513                         s->init_num=0;
514                         break;
515
516                 case SSL3_ST_SW_CERT_REQ_A:
517                 case SSL3_ST_SW_CERT_REQ_B:
518                         if (/* don't request cert unless asked for it: */
519                                 !(s->verify_mode & SSL_VERIFY_PEER) ||
520                                 /* if SSL_VERIFY_CLIENT_ONCE is set,
521                                  * don't request cert during re-negotiation: */
522                                 ((s->session->peer != NULL) &&
523                                  (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
524                                 /* never request cert in anonymous ciphersuites
525                                  * (see section "Certificate request" in SSL 3 drafts
526                                  * and in RFC 2246): */
527                                 ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
528                                  /* ... except when the application insists on verification
529                                   * (against the specs, but s3_clnt.c accepts this for SSL 3) */
530                                  !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
531                                  /* never request cert in Kerberos ciphersuites */
532                                 (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
533                                 /* With normal PSK Certificates and
534                                  * Certificate Requests are omitted */
535                                 || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK))
536                                 {
537                                 /* no cert request */
538                                 skip=1;
539                                 s->s3->tmp.cert_request=0;
540                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
541 #ifndef OPENSSL_NO_SCTP
542                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
543                                         {
544                                         s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
545                                         s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
546                                         }
547 #endif
548                                 }
549                         else
550                                 {
551                                 s->s3->tmp.cert_request=1;
552                                 dtls1_start_timer(s);
553                                 ret=ssl3_send_certificate_request(s);
554                                 if (ret <= 0) goto end;
555 #ifndef NETSCAPE_HANG_BUG
556                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
557 #ifndef OPENSSL_NO_SCTP
558                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
559                                         {
560                                         s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
561                                         s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
562                                         }
563 #endif
564 #else
565                                 s->state=SSL3_ST_SW_FLUSH;
566                                 s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
567 #ifndef OPENSSL_NO_SCTP
568                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
569                                         {
570                                         s->d1->next_state = s->s3->tmp.next_state;
571                                         s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
572                                         }
573 #endif
574 #endif
575                                 s->init_num=0;
576                                 }
577                         break;
578
579                 case SSL3_ST_SW_SRVR_DONE_A:
580                 case SSL3_ST_SW_SRVR_DONE_B:
581                         dtls1_start_timer(s);
582                         ret=ssl3_send_server_done(s);
583                         if (ret <= 0) goto end;
584                         s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
585                         s->state=SSL3_ST_SW_FLUSH;
586                         s->init_num=0;
587                         break;
588                 
589                 case SSL3_ST_SW_FLUSH:
590                         s->rwstate=SSL_WRITING;
591                         if (BIO_flush(s->wbio) <= 0)
592                                 {
593                                 /* If the write error was fatal, stop trying */
594                                 if (!BIO_should_retry(s->wbio))
595                                         {
596                                         s->rwstate=SSL_NOTHING;
597                                         s->state=s->s3->tmp.next_state;
598                                         }
599                                 
600                                 ret= -1;
601                                 goto end;
602                                 }
603                         s->rwstate=SSL_NOTHING;
604                         s->state=s->s3->tmp.next_state;
605                         break;
606
607                 case SSL3_ST_SR_CERT_A:
608                 case SSL3_ST_SR_CERT_B:
609                         /* Check for second client hello (MS SGC) */
610                         ret = ssl3_check_client_hello(s);
611                         if (ret <= 0)
612                                 goto end;
613                         if (ret == 2)
614                                 {
615                                 dtls1_stop_timer(s);
616                                 s->state = SSL3_ST_SR_CLNT_HELLO_C;
617                                 }
618                         else {
619                                 /* could be sent for a DH cert, even if we
620                                  * have not asked for it :-) */
621                                 ret=ssl3_get_client_certificate(s);
622                                 if (ret <= 0) goto end;
623                                 s->init_num=0;
624                                 s->state=SSL3_ST_SR_KEY_EXCH_A;
625                         }
626                         break;
627
628                 case SSL3_ST_SR_KEY_EXCH_A:
629                 case SSL3_ST_SR_KEY_EXCH_B:
630                         ret=ssl3_get_client_key_exchange(s);
631                         if (ret <= 0) goto end;
632 #ifndef OPENSSL_NO_SCTP
633                         /* Add new shared key for SCTP-Auth,
634                          * will be ignored if no SCTP used.
635                          */
636                         snprintf((char *) labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
637                                  DTLS1_SCTP_AUTH_LABEL);
638
639                         SSL_export_keying_material(s, sctpauthkey,
640                                                    sizeof(sctpauthkey), labelbuffer,
641                                                    sizeof(labelbuffer), NULL, 0, 0);
642
643                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
644                                  sizeof(sctpauthkey), sctpauthkey);
645 #endif
646
647                         s->state=SSL3_ST_SR_CERT_VRFY_A;
648                         s->init_num=0;
649
650                         if (ret == 2)
651                                 {
652                                 /* For the ECDH ciphersuites when
653                                  * the client sends its ECDH pub key in
654                                  * a certificate, the CertificateVerify
655                                  * message is not sent.
656                                  */
657                                 s->state=SSL3_ST_SR_FINISHED_A;
658                                 s->init_num = 0;
659                                 }
660                         else if (SSL_USE_SIGALGS(s))
661                                 {
662                                 s->state=SSL3_ST_SR_CERT_VRFY_A;
663                                 s->init_num=0;
664                                 if (!s->session->peer)
665                                         break;
666                                 /* For sigalgs freeze the handshake buffer
667                                  * at this point and digest cached records.
668                                  */
669                                 if (!s->s3->handshake_buffer)
670                                         {
671                                         SSLerr(SSL_F_DTLS1_ACCEPT,ERR_R_INTERNAL_ERROR);
672                                         return -1;
673                                         }
674                                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
675                                 if (!ssl3_digest_cached_records(s))
676                                         return -1;
677                                 }
678                         else
679                                 {
680                                 s->state=SSL3_ST_SR_CERT_VRFY_A;
681                                 s->init_num=0;
682
683                                 /* We need to get hashes here so if there is
684                                  * a client cert, it can be verified */ 
685                                 s->method->ssl3_enc->cert_verify_mac(s,
686                                         NID_md5,
687                                         &(s->s3->tmp.cert_verify_md[0]));
688                                 s->method->ssl3_enc->cert_verify_mac(s,
689                                         NID_sha1,
690                                         &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
691                                 }
692                         break;
693
694                 case SSL3_ST_SR_CERT_VRFY_A:
695                 case SSL3_ST_SR_CERT_VRFY_B:
696
697                         s->d1->change_cipher_spec_ok = 1;
698                         /* we should decide if we expected this one */
699                         ret=ssl3_get_cert_verify(s);
700                         if (ret <= 0) goto end;
701 #ifndef OPENSSL_NO_SCTP
702                         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
703                             state == SSL_ST_RENEGOTIATE)
704                                 s->state=DTLS1_SCTP_ST_SR_READ_SOCK;
705                         else
706 #endif                  
707                                 s->state=SSL3_ST_SR_FINISHED_A;
708                         s->init_num=0;
709                         break;
710
711                 case SSL3_ST_SR_FINISHED_A:
712                 case SSL3_ST_SR_FINISHED_B:
713                         s->d1->change_cipher_spec_ok = 1;
714                         ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
715                                 SSL3_ST_SR_FINISHED_B);
716                         if (ret <= 0) goto end;
717                         dtls1_stop_timer(s);
718                         if (s->hit)
719                                 s->state=SSL_ST_OK;
720 #ifndef OPENSSL_NO_TLSEXT
721                         else if (s->tlsext_ticket_expected)
722                                 s->state=SSL3_ST_SW_SESSION_TICKET_A;
723 #endif
724                         else
725                                 s->state=SSL3_ST_SW_CHANGE_A;
726                         s->init_num=0;
727                         break;
728
729 #ifndef OPENSSL_NO_TLSEXT
730                 case SSL3_ST_SW_SESSION_TICKET_A:
731                 case SSL3_ST_SW_SESSION_TICKET_B:
732                         ret=ssl3_send_newsession_ticket(s);
733                         if (ret <= 0) goto end;
734                         s->state=SSL3_ST_SW_CHANGE_A;
735                         s->init_num=0;
736                         break;
737
738                 case SSL3_ST_SW_CERT_STATUS_A:
739                 case SSL3_ST_SW_CERT_STATUS_B:
740                         ret=ssl3_send_cert_status(s);
741                         if (ret <= 0) goto end;
742                         s->state=SSL3_ST_SW_KEY_EXCH_A;
743                         s->init_num=0;
744                         break;
745
746 #endif
747
748                 case SSL3_ST_SW_CHANGE_A:
749                 case SSL3_ST_SW_CHANGE_B:
750
751                         s->session->cipher=s->s3->tmp.new_cipher;
752                         if (!s->method->ssl3_enc->setup_key_block(s))
753                                 { ret= -1; goto end; }
754
755                         ret=dtls1_send_change_cipher_spec(s,
756                                 SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
757
758                         if (ret <= 0) goto end;
759
760 #ifndef OPENSSL_NO_SCTP
761                         if (!s->hit)
762                                 {
763                                 /* Change to new shared key of SCTP-Auth,
764                                  * will be ignored if no SCTP used.
765                                  */
766                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
767                                 }
768 #endif
769
770                         s->state=SSL3_ST_SW_FINISHED_A;
771                         s->init_num=0;
772
773                         if (!s->method->ssl3_enc->change_cipher_state(s,
774                                 SSL3_CHANGE_CIPHER_SERVER_WRITE))
775                                 {
776                                 ret= -1;
777                                 goto end;
778                                 }
779
780                         dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
781                         break;
782
783                 case SSL3_ST_SW_FINISHED_A:
784                 case SSL3_ST_SW_FINISHED_B:
785                         ret=ssl3_send_finished(s,
786                                 SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
787                                 s->method->ssl3_enc->server_finished_label,
788                                 s->method->ssl3_enc->server_finished_label_len);
789                         if (ret <= 0) goto end;
790                         s->state=SSL3_ST_SW_FLUSH;
791                         if (s->hit)
792                                 {
793                                 s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
794
795 #ifndef OPENSSL_NO_SCTP
796                                 /* Change to new shared key of SCTP-Auth,
797                                  * will be ignored if no SCTP used.
798                                  */
799                                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY, 0, NULL);
800 #endif
801                                 }
802                         else
803                                 {
804                                 s->s3->tmp.next_state=SSL_ST_OK;
805 #ifndef OPENSSL_NO_SCTP
806                                 if (BIO_dgram_is_sctp(SSL_get_wbio(s)))
807                                         {
808                                         s->d1->next_state = s->s3->tmp.next_state;
809                                         s->s3->tmp.next_state=DTLS1_SCTP_ST_SW_WRITE_SOCK;
810                                         }
811 #endif
812                                 }
813                         s->init_num=0;
814                         break;
815
816                 case SSL_ST_OK:
817                         /* clean a few things up */
818                         ssl3_cleanup_key_block(s);
819
820 #if 0
821                         BUF_MEM_free(s->init_buf);
822                         s->init_buf=NULL;
823 #endif
824
825                         /* remove buffering on output */
826                         ssl_free_wbio_buffer(s);
827
828                         s->init_num=0;
829
830                         if (s->renegotiate == 2) /* skipped if we just sent a HelloRequest */
831                                 {
832                                 s->renegotiate=0;
833                                 s->new_session=0;
834                                 
835                                 ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
836                                 
837                                 s->ctx->stats.sess_accept_good++;
838                                 /* s->server=1; */
839                                 s->handshake_func=dtls1_accept;
840
841                                 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
842                                 }
843                         
844                         ret = 1;
845
846                         /* done handshaking, next message is client hello */
847                         s->d1->handshake_read_seq = 0;
848                         /* next message is server hello */
849                         s->d1->handshake_write_seq = 0;
850                         s->d1->next_handshake_write_seq = 0;
851                         goto end;
852                         /* break; */
853
854                 default:
855                         SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_UNKNOWN_STATE);
856                         ret= -1;
857                         goto end;
858                         /* break; */
859                         }
860                 
861                 if (!s->s3->tmp.reuse_message && !skip)
862                         {
863                         if (s->debug)
864                                 {
865                                 if ((ret=BIO_flush(s->wbio)) <= 0)
866                                         goto end;
867                                 }
868
869
870                         if ((cb != NULL) && (s->state != state))
871                                 {
872                                 new_state=s->state;
873                                 s->state=state;
874                                 cb(s,SSL_CB_ACCEPT_LOOP,1);
875                                 s->state=new_state;
876                                 }
877                         }
878                 skip=0;
879                 }
880 end:
881         /* BIO_flush(s->wbio); */
882
883         s->in_handshake--;
884 #ifndef OPENSSL_NO_SCTP
885                 /* Notify SCTP BIO socket to leave handshake
886                  * mode and prevent stream identifier other
887                  * than 0. Will be ignored if no SCTP is used.
888                  */
889                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE, s->in_handshake, NULL);
890 #endif
891
892         if (cb != NULL)
893                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
894         return(ret);
895         }
896
897 int dtls1_send_hello_verify_request(SSL *s)
898         {
899         unsigned int msg_len;
900         unsigned char *msg, *buf, *p;
901
902         if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A)
903                 {
904                 buf = (unsigned char *)s->init_buf->data;
905
906                 msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
907                 /* Always use DTLS 1.0 version: see RFC 6347 */
908                 *(p++) = DTLS1_VERSION >> 8;
909                 *(p++) = DTLS1_VERSION & 0xFF;
910
911                 if (s->ctx->app_gen_cookie_cb == NULL ||
912                      s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
913                          &(s->d1->cookie_len)) == 0)
914                         {
915                         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,ERR_R_INTERNAL_ERROR);
916                         return 0;
917                         }
918
919                 *(p++) = (unsigned char) s->d1->cookie_len;
920                 memcpy(p, s->d1->cookie, s->d1->cookie_len);
921                 p += s->d1->cookie_len;
922                 msg_len = p - msg;
923
924                 dtls1_set_message_header(s, buf,
925                         DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len);
926
927                 s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
928                 /* number of bytes to write */
929                 s->init_num=p-buf;
930                 s->init_off=0;
931                 }
932
933         /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
934         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
935         }