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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 #ifndef OPENSSL_NO_DH
125 #include <openssl/dh.h>
126 #endif
127
128 static const SSL_METHOD *dtls1_get_server_method(int ver);
129 static int dtls1_send_hello_verify_request(SSL *s);
130
131 static const SSL_METHOD *dtls1_get_server_method(int ver)
132         {
133         if (ver == DTLS1_VERSION)
134                 return(DTLSv1_server_method());
135         else
136                 return(NULL);
137         }
138
139 IMPLEMENT_dtls1_meth_func(DTLSv1_server_method,
140                         dtls1_accept,
141                         ssl_undefined_function,
142                         dtls1_get_server_method)
143
144 int dtls1_accept(SSL *s)
145         {
146         BUF_MEM *buf;
147         unsigned long Time=(unsigned long)time(NULL);
148         void (*cb)(const SSL *ssl,int type,int val)=NULL;
149         long num1;
150         unsigned long alg_k;
151         int ret= -1;
152         int new_state,state,skip=0;
153
154         RAND_add(&Time,sizeof(Time),0);
155         ERR_clear_error();
156         clear_sys_error();
157
158         if (s->info_callback != NULL)
159                 cb=s->info_callback;
160         else if (s->ctx->info_callback != NULL)
161                 cb=s->ctx->info_callback;
162
163         /* init things to blank */
164         s->in_handshake++;
165         if (!SSL_in_init(s) || SSL_in_before(s)) SSL_clear(s);
166
167         if (s->cert == NULL)
168                 {
169                 SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_NO_CERTIFICATE_SET);
170                 return(-1);
171                 }
172
173         for (;;)
174                 {
175                 state=s->state;
176
177                 switch (s->state)
178                         {
179                 case SSL_ST_RENEGOTIATE:
180                         s->new_session=1;
181                         /* s->state=SSL_ST_ACCEPT; */
182
183                 case SSL_ST_BEFORE:
184                 case SSL_ST_ACCEPT:
185                 case SSL_ST_BEFORE|SSL_ST_ACCEPT:
186                 case SSL_ST_OK|SSL_ST_ACCEPT:
187
188                         s->server=1;
189                         if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
190
191                         if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00))
192                                 {
193                                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
194                                 return -1;
195                                 }
196                         s->type=SSL_ST_ACCEPT;
197
198                         if (s->init_buf == NULL)
199                                 {
200                                 if ((buf=BUF_MEM_new()) == NULL)
201                                         {
202                                         ret= -1;
203                                         goto end;
204                                         }
205                                 if (!BUF_MEM_grow(buf,SSL3_RT_MAX_PLAIN_LENGTH))
206                                         {
207                                         ret= -1;
208                                         goto end;
209                                         }
210                                 s->init_buf=buf;
211                                 }
212
213                         if (!ssl3_setup_buffers(s))
214                                 {
215                                 ret= -1;
216                                 goto end;
217                                 }
218
219                         s->init_num=0;
220
221                         if (s->state != SSL_ST_RENEGOTIATE)
222                                 {
223                                 /* Ok, we now need to push on a buffering BIO so that
224                                  * the output is sent in a way that TCP likes :-)
225                                  */
226                                 if (!ssl_init_wbio_buffer(s,1)) { ret= -1; goto end; }
227
228                                 ssl3_init_finished_mac(s);
229                                 s->state=SSL3_ST_SR_CLNT_HELLO_A;
230                                 s->ctx->stats.sess_accept++;
231                                 }
232                         else
233                                 {
234                                 /* s->state == SSL_ST_RENEGOTIATE,
235                                  * we will just send a HelloRequest */
236                                 s->ctx->stats.sess_accept_renegotiate++;
237                                 s->state=SSL3_ST_SW_HELLO_REQ_A;
238                                 }
239
240                         if ( (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
241                                 s->d1->send_cookie = 1;
242                         else
243                                 s->d1->send_cookie = 0;
244                         
245                         break;
246
247                 case SSL3_ST_SW_HELLO_REQ_A:
248                 case SSL3_ST_SW_HELLO_REQ_B:
249
250                         s->shutdown=0;
251                         ret=dtls1_send_hello_request(s);
252                         if (ret <= 0) goto end;
253                         s->s3->tmp.next_state=SSL3_ST_SW_HELLO_REQ_C;
254                         s->state=SSL3_ST_SW_FLUSH;
255                         s->init_num=0;
256
257                         ssl3_init_finished_mac(s);
258                         break;
259
260                 case SSL3_ST_SW_HELLO_REQ_C:
261                         s->state=SSL_ST_OK;
262                         break;
263
264                 case SSL3_ST_SR_CLNT_HELLO_A:
265                 case SSL3_ST_SR_CLNT_HELLO_B:
266                 case SSL3_ST_SR_CLNT_HELLO_C:
267
268                         s->shutdown=0;
269                         ret=ssl3_get_client_hello(s);
270                         if (ret <= 0) goto end;
271                         s->new_session = 2;
272
273                         if (s->d1->send_cookie)
274                                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
275                         else
276                                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
277
278                         s->init_num=0;
279                         break;
280                         
281                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
282                 case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
283
284                         ret = dtls1_send_hello_verify_request(s);
285                         if ( ret <= 0) goto end;
286                         s->d1->send_cookie = 0;
287                         s->state=SSL3_ST_SW_FLUSH;
288                         s->s3->tmp.next_state=SSL3_ST_SR_CLNT_HELLO_A;
289
290                         /* HelloVerifyRequest resets Finished MAC */
291                         ssl3_init_finished_mac(s);
292                         break;
293                         
294                 case SSL3_ST_SW_SRVR_HELLO_A:
295                 case SSL3_ST_SW_SRVR_HELLO_B:
296                         ret=dtls1_send_server_hello(s);
297                         if (ret <= 0) goto end;
298
299                         if (s->hit)
300                                 s->state=SSL3_ST_SW_CHANGE_A;
301                         else
302                                 s->state=SSL3_ST_SW_CERT_A;
303                         s->init_num=0;
304                         break;
305
306                 case SSL3_ST_SW_CERT_A:
307                 case SSL3_ST_SW_CERT_B:
308                         /* Check if it is anon DH */
309                         if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
310                                 {
311                                 ret=dtls1_send_server_certificate(s);
312                                 if (ret <= 0) goto end;
313                                 }
314                         else
315                                 skip=1;
316                         s->state=SSL3_ST_SW_KEY_EXCH_A;
317                         s->init_num=0;
318                         break;
319
320                 case SSL3_ST_SW_KEY_EXCH_A:
321                 case SSL3_ST_SW_KEY_EXCH_B:
322                         alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
323
324                         /* clear this, it may get reset by
325                          * send_server_key_exchange */
326                         if ((s->options & SSL_OP_EPHEMERAL_RSA)
327 #ifndef OPENSSL_NO_KRB5
328                                 && !(alg_k & SSL_kKRB5)
329 #endif /* OPENSSL_NO_KRB5 */
330                                 )
331                                 /* option SSL_OP_EPHEMERAL_RSA sends temporary RSA key
332                                  * even when forbidden by protocol specs
333                                  * (handshake may fail as clients are not required to
334                                  * be able to handle this) */
335                                 s->s3->tmp.use_rsa_tmp=1;
336                         else
337                                 s->s3->tmp.use_rsa_tmp=0;
338
339                         /* only send if a DH key exchange or
340                          * RSA but we have a sign only certificate */
341                         if (s->s3->tmp.use_rsa_tmp
342                             || (alg_k & (SSL_kEDH|SSL_kDHr|SSL_kDHd))
343                             || ((alg_k & SSL_kRSA)
344                                 && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
345                                     || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
346                                         && EVP_PKEY_size(s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey)*8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
347                                         )
348                                     )
349                                 )
350                             )
351                                 {
352                                 ret=dtls1_send_server_key_exchange(s);
353                                 if (ret <= 0) goto end;
354                                 }
355                         else
356                                 skip=1;
357
358                         s->state=SSL3_ST_SW_CERT_REQ_A;
359                         s->init_num=0;
360                         break;
361
362                 case SSL3_ST_SW_CERT_REQ_A:
363                 case SSL3_ST_SW_CERT_REQ_B:
364                         if (/* don't request cert unless asked for it: */
365                                 !(s->verify_mode & SSL_VERIFY_PEER) ||
366                                 /* if SSL_VERIFY_CLIENT_ONCE is set,
367                                  * don't request cert during re-negotiation: */
368                                 ((s->session->peer != NULL) &&
369                                  (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
370                                 /* never request cert in anonymous ciphersuites
371                                  * (see section "Certificate request" in SSL 3 drafts
372                                  * and in RFC 2246): */
373                                 ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
374                                  /* ... except when the application insists on verification
375                                   * (against the specs, but s3_clnt.c accepts this for SSL 3) */
376                                  !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
377                                  /* never request cert in Kerberos ciphersuites */
378                                 (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5))
379                                 {
380                                 /* no cert request */
381                                 skip=1;
382                                 s->s3->tmp.cert_request=0;
383                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
384                                 }
385                         else
386                                 {
387                                 s->s3->tmp.cert_request=1;
388                                 ret=dtls1_send_certificate_request(s);
389                                 if (ret <= 0) goto end;
390 #ifndef NETSCAPE_HANG_BUG
391                                 s->state=SSL3_ST_SW_SRVR_DONE_A;
392 #else
393                                 s->state=SSL3_ST_SW_FLUSH;
394                                 s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
395 #endif
396                                 s->init_num=0;
397                                 }
398                         break;
399
400                 case SSL3_ST_SW_SRVR_DONE_A:
401                 case SSL3_ST_SW_SRVR_DONE_B:
402                         ret=dtls1_send_server_done(s);
403                         if (ret <= 0) goto end;
404                         s->s3->tmp.next_state=SSL3_ST_SR_CERT_A;
405                         s->state=SSL3_ST_SW_FLUSH;
406                         s->init_num=0;
407                         break;
408                 
409                 case SSL3_ST_SW_FLUSH:
410                         /* number of bytes to be flushed */
411                         num1=BIO_ctrl(s->wbio,BIO_CTRL_INFO,0,NULL);
412                         if (num1 > 0)
413                                 {
414                                 s->rwstate=SSL_WRITING;
415                                 num1=BIO_flush(s->wbio);
416                                 if (num1 <= 0) { ret= -1; goto end; }
417                                 s->rwstate=SSL_NOTHING;
418                                 }
419
420                         s->state=s->s3->tmp.next_state;
421                         break;
422
423                 case SSL3_ST_SR_CERT_A:
424                 case SSL3_ST_SR_CERT_B:
425                         /* Check for second client hello (MS SGC) */
426                         ret = ssl3_check_client_hello(s);
427                         if (ret <= 0)
428                                 goto end;
429                         if (ret == 2)
430                                 s->state = SSL3_ST_SR_CLNT_HELLO_C;
431                         else {
432                                 /* could be sent for a DH cert, even if we
433                                  * have not asked for it :-) */
434                                 ret=ssl3_get_client_certificate(s);
435                                 if (ret <= 0) goto end;
436                                 s->init_num=0;
437                                 s->state=SSL3_ST_SR_KEY_EXCH_A;
438                         }
439                         break;
440
441                 case SSL3_ST_SR_KEY_EXCH_A:
442                 case SSL3_ST_SR_KEY_EXCH_B:
443                         ret=ssl3_get_client_key_exchange(s);
444                         if (ret <= 0) goto end;
445                         s->state=SSL3_ST_SR_CERT_VRFY_A;
446                         s->init_num=0;
447
448                         /* We need to get hashes here so if there is
449                          * a client cert, it can be verified */ 
450                         s->method->ssl3_enc->cert_verify_mac(s,
451                                 NID_md5,
452                                 &(s->s3->tmp.cert_verify_md[0]));
453                         s->method->ssl3_enc->cert_verify_mac(s,
454                                 NID_sha1,
455                                 &(s->s3->tmp.cert_verify_md[MD5_DIGEST_LENGTH]));
456
457                         break;
458
459                 case SSL3_ST_SR_CERT_VRFY_A:
460                 case SSL3_ST_SR_CERT_VRFY_B:
461
462                         /* we should decide if we expected this one */
463                         ret=ssl3_get_cert_verify(s);
464                         if (ret <= 0) goto end;
465
466                         s->state=SSL3_ST_SR_FINISHED_A;
467                         s->init_num=0;
468                         break;
469
470                 case SSL3_ST_SR_FINISHED_A:
471                 case SSL3_ST_SR_FINISHED_B:
472                         ret=ssl3_get_finished(s,SSL3_ST_SR_FINISHED_A,
473                                 SSL3_ST_SR_FINISHED_B);
474                         if (ret <= 0) goto end;
475                         if (s->hit)
476                                 s->state=SSL_ST_OK;
477                         else
478                                 s->state=SSL3_ST_SW_CHANGE_A;
479                         s->init_num=0;
480                         break;
481
482                 case SSL3_ST_SW_CHANGE_A:
483                 case SSL3_ST_SW_CHANGE_B:
484
485                         s->session->cipher=s->s3->tmp.new_cipher;
486                         if (!s->method->ssl3_enc->setup_key_block(s))
487                                 { ret= -1; goto end; }
488
489                         ret=dtls1_send_change_cipher_spec(s,
490                                 SSL3_ST_SW_CHANGE_A,SSL3_ST_SW_CHANGE_B);
491
492                         if (ret <= 0) goto end;
493                         s->state=SSL3_ST_SW_FINISHED_A;
494                         s->init_num=0;
495
496                         if (!s->method->ssl3_enc->change_cipher_state(s,
497                                 SSL3_CHANGE_CIPHER_SERVER_WRITE))
498                                 {
499                                 ret= -1;
500                                 goto end;
501                                 }
502
503                         dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
504                         break;
505
506                 case SSL3_ST_SW_FINISHED_A:
507                 case SSL3_ST_SW_FINISHED_B:
508                         ret=dtls1_send_finished(s,
509                                 SSL3_ST_SW_FINISHED_A,SSL3_ST_SW_FINISHED_B,
510                                 s->method->ssl3_enc->server_finished_label,
511                                 s->method->ssl3_enc->server_finished_label_len);
512                         if (ret <= 0) goto end;
513                         s->state=SSL3_ST_SW_FLUSH;
514                         if (s->hit)
515                                 s->s3->tmp.next_state=SSL3_ST_SR_FINISHED_A;
516                         else
517                                 s->s3->tmp.next_state=SSL_ST_OK;
518                         s->init_num=0;
519                         break;
520
521                 case SSL_ST_OK:
522                         /* clean a few things up */
523                         ssl3_cleanup_key_block(s);
524
525 #if 0
526                         BUF_MEM_free(s->init_buf);
527                         s->init_buf=NULL;
528 #endif
529
530                         /* remove buffering on output */
531                         ssl_free_wbio_buffer(s);
532
533                         s->init_num=0;
534
535                         if (s->new_session == 2) /* skipped if we just sent a HelloRequest */
536                                 {
537                                 /* actually not necessarily a 'new' session unless
538                                  * SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION is set */
539                                 
540                                 s->new_session=0;
541                                 
542                                 ssl_update_cache(s,SSL_SESS_CACHE_SERVER);
543                                 
544                                 s->ctx->stats.sess_accept_good++;
545                                 /* s->server=1; */
546                                 s->handshake_func=dtls1_accept;
547
548                                 if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_DONE,1);
549                                 }
550                         
551                         ret = 1;
552
553                         /* done handshaking, next message is client hello */
554                         s->d1->handshake_read_seq = 0;
555                         /* next message is server hello */
556                         s->d1->handshake_write_seq = 0;
557                         goto end;
558                         /* break; */
559
560                 default:
561                         SSLerr(SSL_F_DTLS1_ACCEPT,SSL_R_UNKNOWN_STATE);
562                         ret= -1;
563                         goto end;
564                         /* break; */
565                         }
566                 
567                 if (!s->s3->tmp.reuse_message && !skip)
568                         {
569                         if (s->debug)
570                                 {
571                                 if ((ret=BIO_flush(s->wbio)) <= 0)
572                                         goto end;
573                                 }
574
575
576                         if ((cb != NULL) && (s->state != state))
577                                 {
578                                 new_state=s->state;
579                                 s->state=state;
580                                 cb(s,SSL_CB_ACCEPT_LOOP,1);
581                                 s->state=new_state;
582                                 }
583                         }
584                 skip=0;
585                 }
586 end:
587         /* BIO_flush(s->wbio); */
588
589         s->in_handshake--;
590         if (cb != NULL)
591                 cb(s,SSL_CB_ACCEPT_EXIT,ret);
592         return(ret);
593         }
594
595 int dtls1_send_hello_request(SSL *s)
596         {
597         unsigned char *p;
598
599         if (s->state == SSL3_ST_SW_HELLO_REQ_A)
600                 {
601                 p=(unsigned char *)s->init_buf->data;
602                 p = dtls1_set_message_header(s, p, SSL3_MT_HELLO_REQUEST, 0, 0, 0);
603
604                 s->state=SSL3_ST_SW_HELLO_REQ_B;
605                 /* number of bytes to write */
606                 s->init_num=DTLS1_HM_HEADER_LENGTH;
607                 s->init_off=0;
608
609                 /* no need to buffer this message, since there are no retransmit 
610                  * requests for it */
611                 }
612
613         /* SSL3_ST_SW_HELLO_REQ_B */
614         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
615         }
616
617 int dtls1_send_hello_verify_request(SSL *s)
618         {
619         unsigned int msg_len;
620         unsigned char *msg, *buf, *p;
621
622         if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A)
623                 {
624                 buf = (unsigned char *)s->init_buf->data;
625
626                 msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
627                 *(p++) = s->version >> 8;
628                 *(p++) = s->version & 0xFF;
629
630                 if (s->ctx->app_gen_cookie_cb != NULL &&
631                     s->ctx->app_gen_cookie_cb(s, s->d1->cookie, 
632                         &(s->d1->cookie_len)) == 0)
633                         {
634                         SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,ERR_R_INTERNAL_ERROR);
635                         return 0;
636                         }
637                 /* else the cookie is assumed to have 
638                  * been initialized by the application */
639
640                 *(p++) = (unsigned char) s->d1->cookie_len;
641                 memcpy(p, s->d1->cookie, s->d1->cookie_len);
642                 p += s->d1->cookie_len;
643                 msg_len = p - msg;
644
645                 dtls1_set_message_header(s, buf,
646                         DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0, msg_len);
647
648                 s->state=DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
649                 /* number of bytes to write */
650                 s->init_num=p-buf;
651                 s->init_off=0;
652
653                 /* buffer the message to handle re-xmits */
654                 dtls1_buffer_message(s, 0);
655                 }
656
657         /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
658         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
659         }
660
661 int dtls1_send_server_hello(SSL *s)
662         {
663         unsigned char *buf;
664         unsigned char *p,*d;
665         int i;
666         unsigned int sl;
667         unsigned long l,Time;
668
669         if (s->state == SSL3_ST_SW_SRVR_HELLO_A)
670                 {
671                 buf=(unsigned char *)s->init_buf->data;
672                 p=s->s3->server_random;
673                 Time=(unsigned long)time(NULL);                 /* Time */
674                 l2n(Time,p);
675                 RAND_pseudo_bytes(p,SSL3_RANDOM_SIZE-sizeof(Time));
676                 /* Do the message type and length last */
677                 d=p= &(buf[DTLS1_HM_HEADER_LENGTH]);
678
679                 *(p++)=s->version>>8;
680                 *(p++)=s->version&0xff;
681
682                 /* Random stuff */
683                 memcpy(p,s->s3->server_random,SSL3_RANDOM_SIZE);
684                 p+=SSL3_RANDOM_SIZE;
685
686                 /* now in theory we have 3 options to sending back the
687                  * session id.  If it is a re-use, we send back the
688                  * old session-id, if it is a new session, we send
689                  * back the new session-id or we send back a 0 length
690                  * session-id if we want it to be single use.
691                  * Currently I will not implement the '0' length session-id
692                  * 12-Jan-98 - I'll now support the '0' length stuff.
693                  */
694                 if (!(s->ctx->session_cache_mode & SSL_SESS_CACHE_SERVER))
695                         s->session->session_id_length=0;
696
697                 sl=s->session->session_id_length;
698                 if (sl > sizeof s->session->session_id)
699                         {
700                         SSLerr(SSL_F_DTLS1_SEND_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
701                         return -1;
702                         }
703                 *(p++)=sl;
704                 memcpy(p,s->session->session_id,sl);
705                 p+=sl;
706
707                 /* put the cipher */
708                 i=ssl3_put_cipher_by_char(s->s3->tmp.new_cipher,p);
709                 p+=i;
710
711                 /* put the compression method */
712 #ifdef OPENSSL_NO_COMP
713                 *(p++)=0;
714 #else
715                 if (s->s3->tmp.new_compression == NULL)
716                         *(p++)=0;
717                 else
718                         *(p++)=s->s3->tmp.new_compression->id;
719 #endif
720
721                 /* do the header */
722                 l=(p-d);
723                 d=buf;
724
725                 d = dtls1_set_message_header(s, d, SSL3_MT_SERVER_HELLO, l, 0, l);
726
727                 s->state=SSL3_ST_CW_CLNT_HELLO_B;
728                 /* number of bytes to write */
729                 s->init_num=p-buf;
730                 s->init_off=0;
731
732                 /* buffer the message to handle re-xmits */
733                 dtls1_buffer_message(s, 0);
734                 }
735
736         /* SSL3_ST_CW_CLNT_HELLO_B */
737         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
738         }
739
740 int dtls1_send_server_done(SSL *s)
741         {
742         unsigned char *p;
743
744         if (s->state == SSL3_ST_SW_SRVR_DONE_A)
745                 {
746                 p=(unsigned char *)s->init_buf->data;
747
748                 /* do the header */
749                 p = dtls1_set_message_header(s, p, SSL3_MT_SERVER_DONE, 0, 0, 0);
750
751                 s->state=SSL3_ST_SW_SRVR_DONE_B;
752                 /* number of bytes to write */
753                 s->init_num=DTLS1_HM_HEADER_LENGTH;
754                 s->init_off=0;
755
756                 /* buffer the message to handle re-xmits */
757                 dtls1_buffer_message(s, 0);
758                 }
759
760         /* SSL3_ST_CW_CLNT_HELLO_B */
761         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
762         }
763
764 int dtls1_send_server_key_exchange(SSL *s)
765         {
766 #ifndef OPENSSL_NO_RSA
767         unsigned char *q;
768         int j,num;
769         RSA *rsa;
770         unsigned char md_buf[MD5_DIGEST_LENGTH+SHA_DIGEST_LENGTH];
771         unsigned int u;
772 #endif
773 #ifndef OPENSSL_NO_DH
774         DH *dh=NULL,*dhp;
775 #endif
776         EVP_PKEY *pkey;
777         unsigned char *p,*d;
778         int al,i;
779         unsigned long type;
780         int n;
781         CERT *cert;
782         BIGNUM *r[4];
783         int nr[4],kn;
784         BUF_MEM *buf;
785         EVP_MD_CTX md_ctx;
786
787         EVP_MD_CTX_init(&md_ctx);
788         if (s->state == SSL3_ST_SW_KEY_EXCH_A)
789                 {
790                 type=s->s3->tmp.new_cipher->algorithm_mkey;
791                 cert=s->cert;
792
793                 buf=s->init_buf;
794
795                 r[0]=r[1]=r[2]=r[3]=NULL;
796                 n=0;
797 #ifndef OPENSSL_NO_RSA
798                 if (type & SSL_kRSA)
799                         {
800                         rsa=cert->rsa_tmp;
801                         if ((rsa == NULL) && (s->cert->rsa_tmp_cb != NULL))
802                                 {
803                                 rsa=s->cert->rsa_tmp_cb(s,
804                                       SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
805                                       SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
806                                 if(rsa == NULL)
807                                 {
808                                         al=SSL_AD_HANDSHAKE_FAILURE;
809                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_ERROR_GENERATING_TMP_RSA_KEY);
810                                         goto f_err;
811                                 }
812                                 RSA_up_ref(rsa);
813                                 cert->rsa_tmp=rsa;
814                                 }
815                         if (rsa == NULL)
816                                 {
817                                 al=SSL_AD_HANDSHAKE_FAILURE;
818                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_RSA_KEY);
819                                 goto f_err;
820                                 }
821                         r[0]=rsa->n;
822                         r[1]=rsa->e;
823                         s->s3->tmp.use_rsa_tmp=1;
824                         }
825                 else
826 #endif
827 #ifndef OPENSSL_NO_DH
828                         if (type & SSL_kEDH)
829                         {
830                         dhp=cert->dh_tmp;
831                         if ((dhp == NULL) && (s->cert->dh_tmp_cb != NULL))
832                                 dhp=s->cert->dh_tmp_cb(s,
833                                       SSL_C_IS_EXPORT(s->s3->tmp.new_cipher),
834                                       SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher));
835                         if (dhp == NULL)
836                                 {
837                                 al=SSL_AD_HANDSHAKE_FAILURE;
838                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_MISSING_TMP_DH_KEY);
839                                 goto f_err;
840                                 }
841
842                         if (s->s3->tmp.dh != NULL)
843                                 {
844                                 DH_free(dh);
845                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE, ERR_R_INTERNAL_ERROR);
846                                 goto err;
847                                 }
848
849                         if ((dh=DHparams_dup(dhp)) == NULL)
850                                 {
851                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
852                                 goto err;
853                                 }
854
855                         s->s3->tmp.dh=dh;
856                         if ((dhp->pub_key == NULL ||
857                              dhp->priv_key == NULL ||
858                              (s->options & SSL_OP_SINGLE_DH_USE)))
859                                 {
860                                 if(!DH_generate_key(dh))
861                                     {
862                                     SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,
863                                            ERR_R_DH_LIB);
864                                     goto err;
865                                     }
866                                 }
867                         else
868                                 {
869                                 dh->pub_key=BN_dup(dhp->pub_key);
870                                 dh->priv_key=BN_dup(dhp->priv_key);
871                                 if ((dh->pub_key == NULL) ||
872                                         (dh->priv_key == NULL))
873                                         {
874                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_R_DH_LIB);
875                                         goto err;
876                                         }
877                                 }
878                         r[0]=dh->p;
879                         r[1]=dh->g;
880                         r[2]=dh->pub_key;
881                         }
882                 else 
883 #endif
884                         {
885                         al=SSL_AD_HANDSHAKE_FAILURE;
886                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_KEY_EXCHANGE_TYPE);
887                         goto f_err;
888                         }
889                 for (i=0; r[i] != NULL; i++)
890                         {
891                         nr[i]=BN_num_bytes(r[i]);
892                         n+=2+nr[i];
893                         }
894
895                 if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL))
896                         {
897                         if ((pkey=ssl_get_sign_pkey(s,s->s3->tmp.new_cipher))
898                                 == NULL)
899                                 {
900                                 al=SSL_AD_DECODE_ERROR;
901                                 goto f_err;
902                                 }
903                         kn=EVP_PKEY_size(pkey);
904                         }
905                 else
906                         {
907                         pkey=NULL;
908                         kn=0;
909                         }
910
911                 if (!BUF_MEM_grow_clean(buf,n+DTLS1_HM_HEADER_LENGTH+kn))
912                         {
913                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_BUF);
914                         goto err;
915                         }
916                 d=(unsigned char *)s->init_buf->data;
917                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
918
919                 for (i=0; r[i] != NULL; i++)
920                         {
921                         s2n(nr[i],p);
922                         BN_bn2bin(r[i],p);
923                         p+=nr[i];
924                         }
925
926                 /* not anonymous */
927                 if (pkey != NULL)
928                         {
929                         /* n is the length of the params, they start at
930                          * &(d[DTLS1_HM_HEADER_LENGTH]) and p points to the space
931                          * at the end. */
932 #ifndef OPENSSL_NO_RSA
933                         if (pkey->type == EVP_PKEY_RSA)
934                                 {
935                                 q=md_buf;
936                                 j=0;
937                                 for (num=2; num > 0; num--)
938                                         {
939                                         EVP_DigestInit_ex(&md_ctx,(num == 2)
940                                                 ?s->ctx->md5:s->ctx->sha1, NULL);
941                                         EVP_DigestUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
942                                         EVP_DigestUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
943                                         EVP_DigestUpdate(&md_ctx,&(d[DTLS1_HM_HEADER_LENGTH]),n);
944                                         EVP_DigestFinal_ex(&md_ctx,q,
945                                                 (unsigned int *)&i);
946                                         q+=i;
947                                         j+=i;
948                                         }
949                                 if (RSA_sign(NID_md5_sha1, md_buf, j,
950                                         &(p[2]), &u, pkey->pkey.rsa) <= 0)
951                                         {
952                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_RSA);
953                                         goto err;
954                                         }
955                                 s2n(u,p);
956                                 n+=u+2;
957                                 }
958                         else
959 #endif
960 #if !defined(OPENSSL_NO_DSA)
961                                 if (pkey->type == EVP_PKEY_DSA)
962                                 {
963                                 /* lets do DSS */
964                                 EVP_SignInit_ex(&md_ctx,EVP_dss1(), NULL);
965                                 EVP_SignUpdate(&md_ctx,&(s->s3->client_random[0]),SSL3_RANDOM_SIZE);
966                                 EVP_SignUpdate(&md_ctx,&(s->s3->server_random[0]),SSL3_RANDOM_SIZE);
967                                 EVP_SignUpdate(&md_ctx,&(d[DTLS1_HM_HEADER_LENGTH]),n);
968                                 if (!EVP_SignFinal(&md_ctx,&(p[2]),
969                                         (unsigned int *)&i,pkey))
970                                         {
971                                         SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,ERR_LIB_DSA);
972                                         goto err;
973                                         }
974                                 s2n(i,p);
975                                 n+=i+2;
976                                 }
977                         else
978 #endif
979                                 {
980                                 /* Is this error check actually needed? */
981                                 al=SSL_AD_HANDSHAKE_FAILURE;
982                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_KEY_EXCHANGE,SSL_R_UNKNOWN_PKEY_TYPE);
983                                 goto f_err;
984                                 }
985                         }
986
987                 d = dtls1_set_message_header(s, d,
988                         SSL3_MT_SERVER_KEY_EXCHANGE, n, 0, n);
989
990                 /* we should now have things packed up, so lets send
991                  * it off */
992                 s->init_num=n+DTLS1_HM_HEADER_LENGTH;
993                 s->init_off=0;
994
995                 /* buffer the message to handle re-xmits */
996                 dtls1_buffer_message(s, 0);
997                 }
998
999         s->state = SSL3_ST_SW_KEY_EXCH_B;
1000         EVP_MD_CTX_cleanup(&md_ctx);
1001         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1002 f_err:
1003         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1004 err:
1005         EVP_MD_CTX_cleanup(&md_ctx);
1006         return(-1);
1007         }
1008
1009 int dtls1_send_certificate_request(SSL *s)
1010         {
1011         unsigned char *p,*d;
1012         int i,j,nl,off,n;
1013         STACK_OF(X509_NAME) *sk=NULL;
1014         X509_NAME *name;
1015         BUF_MEM *buf;
1016         unsigned int msg_len;
1017
1018         if (s->state == SSL3_ST_SW_CERT_REQ_A)
1019                 {
1020                 buf=s->init_buf;
1021
1022                 d=p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1023
1024                 /* get the list of acceptable cert types */
1025                 p++;
1026                 n=ssl3_get_req_cert_type(s,p);
1027                 d[0]=n;
1028                 p+=n;
1029                 n++;
1030
1031                 off=n;
1032                 p+=2;
1033                 n+=2;
1034
1035                 sk=SSL_get_client_CA_list(s);
1036                 nl=0;
1037                 if (sk != NULL)
1038                         {
1039                         for (i=0; i<sk_X509_NAME_num(sk); i++)
1040                                 {
1041                                 name=sk_X509_NAME_value(sk,i);
1042                                 j=i2d_X509_NAME(name,NULL);
1043                                 if (!BUF_MEM_grow_clean(buf,DTLS1_HM_HEADER_LENGTH+n+j+2))
1044                                         {
1045                                         SSLerr(SSL_F_DTLS1_SEND_CERTIFICATE_REQUEST,ERR_R_BUF_LIB);
1046                                         goto err;
1047                                         }
1048                                 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH+n]);
1049                                 if (!(s->options & SSL_OP_NETSCAPE_CA_DN_BUG))
1050                                         {
1051                                         s2n(j,p);
1052                                         i2d_X509_NAME(name,&p);
1053                                         n+=2+j;
1054                                         nl+=2+j;
1055                                         }
1056                                 else
1057                                         {
1058                                         d=p;
1059                                         i2d_X509_NAME(name,&p);
1060                                         j-=2; s2n(j,d); j+=2;
1061                                         n+=j;
1062                                         nl+=j;
1063                                         }
1064                                 }
1065                         }
1066                 /* else no CA names */
1067                 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH+off]);
1068                 s2n(nl,p);
1069
1070                 d=(unsigned char *)buf->data;
1071                 *(d++)=SSL3_MT_CERTIFICATE_REQUEST;
1072                 l2n3(n,d);
1073                 s2n(s->d1->handshake_write_seq,d);
1074                 s->d1->handshake_write_seq++;
1075
1076                 /* we should now have things packed up, so lets send
1077                  * it off */
1078
1079                 s->init_num=n+DTLS1_HM_HEADER_LENGTH;
1080                 s->init_off=0;
1081 #ifdef NETSCAPE_HANG_BUG
1082 /* XXX: what to do about this? */
1083                 p=(unsigned char *)s->init_buf->data + s->init_num;
1084
1085                 /* do the header */
1086                 *(p++)=SSL3_MT_SERVER_DONE;
1087                 *(p++)=0;
1088                 *(p++)=0;
1089                 *(p++)=0;
1090                 s->init_num += 4;
1091 #endif
1092
1093                 /* XDTLS:  set message header ? */
1094                 msg_len = s->init_num - DTLS1_HM_HEADER_LENGTH;
1095                 dtls1_set_message_header(s, (void *)s->init_buf->data,
1096                         SSL3_MT_CERTIFICATE_REQUEST, msg_len, 0, msg_len);
1097
1098                 /* buffer the message to handle re-xmits */
1099                 dtls1_buffer_message(s, 0);
1100
1101                 s->state = SSL3_ST_SW_CERT_REQ_B;
1102                 }
1103
1104         /* SSL3_ST_SW_CERT_REQ_B */
1105         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1106 err:
1107         return(-1);
1108         }
1109
1110 int dtls1_send_server_certificate(SSL *s)
1111         {
1112         unsigned long l;
1113         X509 *x;
1114
1115         if (s->state == SSL3_ST_SW_CERT_A)
1116                 {
1117                 x=ssl_get_server_send_cert(s);
1118                 if (x == NULL)
1119                         {
1120                         /* VRS: allow null cert if auth == KRB5 */
1121                         if ((s->s3->tmp.new_cipher->algorithm_mkey != SSL_kKRB5) ||
1122                             (s->s3->tmp.new_cipher->algorithm_auth != SSL_aKRB5))
1123                                 {
1124                                 SSLerr(SSL_F_DTLS1_SEND_SERVER_CERTIFICATE,ERR_R_INTERNAL_ERROR);
1125                                 return(0);
1126                                 }
1127                         }
1128
1129                 l=dtls1_output_cert_chain(s,x);
1130                 s->state=SSL3_ST_SW_CERT_B;
1131                 s->init_num=(int)l;
1132                 s->init_off=0;
1133
1134                 /* buffer the message to handle re-xmits */
1135                 dtls1_buffer_message(s, 0);
1136                 }
1137
1138         /* SSL3_ST_SW_CERT_B */
1139         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
1140         }