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 
dtls1_get_server_method(int ver)132 static const SSL_METHOD *dtls1_get_server_method(int ver)
133 {
134     if (ver == DTLS_ANY_VERSION)
135         return DTLS_server_method();
136     else if (ver == DTLS1_VERSION)
137         return DTLSv1_server_method();
138     else if (ver == DTLS1_2_VERSION)
139         return DTLSv1_2_server_method();
140     else
141         return NULL;
142 }
143 
IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,DTLSv1_server_method,dtls1_accept,ssl_undefined_function,dtls1_get_server_method,DTLSv1_enc_data)144 IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
145                           DTLSv1_server_method,
146                           dtls1_accept,
147                           ssl_undefined_function,
148                           dtls1_get_server_method, DTLSv1_enc_data)
149 
150 IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
151                           DTLSv1_2_server_method,
152                           dtls1_accept,
153                           ssl_undefined_function,
154                           dtls1_get_server_method, 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, DTLSv1_2_enc_data)
161 
162 int dtls1_accept(SSL *s)
163 {
164     BUF_MEM *buf;
165     unsigned long Time = (unsigned long)time(NULL);
166     void (*cb) (const SSL *ssl, int type, int val) = NULL;
167     unsigned long alg_k;
168     int ret = -1;
169     int new_state, state, skip = 0;
170     int listen;
171 #ifndef OPENSSL_NO_SCTP
172     unsigned char sctpauthkey[64];
173     char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
174 #endif
175 
176     RAND_add(&Time, sizeof(Time), 0);
177     ERR_clear_error();
178     clear_sys_error();
179 
180     if (s->info_callback != NULL)
181         cb = s->info_callback;
182     else if (s->ctx->info_callback != NULL)
183         cb = s->ctx->info_callback;
184 
185     listen = s->d1->listen;
186 
187     /* init things to blank */
188     s->in_handshake++;
189     if (!SSL_in_init(s) || SSL_in_before(s))
190         SSL_clear(s);
191 
192     s->d1->listen = listen;
193 #ifndef OPENSSL_NO_SCTP
194     /*
195      * Notify SCTP BIO socket to enter handshake mode and prevent stream
196      * identifier other 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,
199              s->in_handshake, NULL);
200 #endif
201 
202     if (s->cert == NULL) {
203         SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
204         return (-1);
205     }
206 #ifndef OPENSSL_NO_HEARTBEATS
207     /*
208      * If we're awaiting a HeartbeatResponse, pretend we already got and
209      * don't await it anymore, because Heartbeats don't make sense during
210      * handshakes anyway.
211      */
212     if (s->tlsext_hb_pending) {
213         dtls1_stop_timer(s);
214         s->tlsext_hb_pending = 0;
215         s->tlsext_hb_seq++;
216     }
217 #endif
218 
219     for (;;) {
220         state = s->state;
221 
222         switch (s->state) {
223         case SSL_ST_RENEGOTIATE:
224             s->renegotiate = 1;
225             /* s->state=SSL_ST_ACCEPT; */
226 
227         case SSL_ST_BEFORE:
228         case SSL_ST_ACCEPT:
229         case SSL_ST_BEFORE | SSL_ST_ACCEPT:
230         case SSL_ST_OK | SSL_ST_ACCEPT:
231 
232             s->server = 1;
233             if (cb != NULL)
234                 cb(s, SSL_CB_HANDSHAKE_START, 1);
235 
236             if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
237                 SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
238                 return -1;
239             }
240             s->type = SSL_ST_ACCEPT;
241 
242             if (s->init_buf == NULL) {
243                 if ((buf = BUF_MEM_new()) == NULL) {
244                     ret = -1;
245                     s->state = SSL_ST_ERR;
246                     goto end;
247                 }
248                 if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
249                     BUF_MEM_free(buf);
250                     ret = -1;
251                     s->state = SSL_ST_ERR;
252                     goto end;
253                 }
254                 s->init_buf = buf;
255             }
256 
257             if (!ssl3_setup_buffers(s)) {
258                 ret = -1;
259                 s->state = SSL_ST_ERR;
260                 goto end;
261             }
262 
263             s->init_num = 0;
264             s->d1->change_cipher_spec_ok = 0;
265             /*
266              * Should have been reset by ssl3_get_finished, too.
267              */
268             s->s3->change_cipher_spec = 0;
269 
270             if (s->state != SSL_ST_RENEGOTIATE) {
271                 /*
272                  * Ok, we now need to push on a buffering BIO so that the
273                  * output is sent in a way that TCP likes :-) ...but not with
274                  * SCTP :-)
275                  */
276 #ifndef OPENSSL_NO_SCTP
277                 if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
278 #endif
279                     if (!ssl_init_wbio_buffer(s, 1)) {
280                         ret = -1;
281                         s->state = SSL_ST_ERR;
282                         goto end;
283                     }
284 
285                 ssl3_init_finished_mac(s);
286                 s->state = SSL3_ST_SR_CLNT_HELLO_A;
287                 s->ctx->stats.sess_accept++;
288             } else if (!s->s3->send_connection_binding &&
289                        !(s->options &
290                          SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
291                 /*
292                  * Server attempting to renegotiate with client that doesn't
293                  * support secure renegotiation.
294                  */
295                 SSLerr(SSL_F_DTLS1_ACCEPT,
296                        SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
297                 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
298                 ret = -1;
299                 s->state = SSL_ST_ERR;
300                 goto end;
301             } else {
302                 /*
303                  * s->state == SSL_ST_RENEGOTIATE, we will just send a
304                  * HelloRequest
305                  */
306                 s->ctx->stats.sess_accept_renegotiate++;
307                 s->state = SSL3_ST_SW_HELLO_REQ_A;
308             }
309 
310             break;
311 
312         case SSL3_ST_SW_HELLO_REQ_A:
313         case SSL3_ST_SW_HELLO_REQ_B:
314 
315             s->shutdown = 0;
316             dtls1_clear_sent_buffer(s);
317             dtls1_start_timer(s);
318             ret = ssl3_send_hello_request(s);
319             if (ret <= 0)
320                 goto end;
321             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
322             s->state = SSL3_ST_SW_FLUSH;
323             s->init_num = 0;
324 
325             ssl3_init_finished_mac(s);
326             break;
327 
328         case SSL3_ST_SW_HELLO_REQ_C:
329             s->state = SSL_ST_OK;
330             break;
331 
332         case SSL3_ST_SR_CLNT_HELLO_A:
333         case SSL3_ST_SR_CLNT_HELLO_B:
334         case SSL3_ST_SR_CLNT_HELLO_C:
335 
336             s->shutdown = 0;
337             ret = ssl3_get_client_hello(s);
338             if (ret <= 0)
339                 goto end;
340             dtls1_stop_timer(s);
341 
342             if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
343                 s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
344             else
345                 s->state = SSL3_ST_SW_SRVR_HELLO_A;
346 
347             s->init_num = 0;
348 
349             /*
350              * Reflect ClientHello sequence to remain stateless while
351              * listening
352              */
353             if (listen) {
354                 memcpy(s->s3->write_sequence, s->s3->read_sequence,
355                        sizeof(s->s3->write_sequence));
356             }
357 
358             /* If we're just listening, stop here */
359             if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) {
360                 ret = 2;
361                 s->d1->listen = 0;
362                 /*
363                  * Set expected sequence numbers to continue the handshake.
364                  */
365                 s->d1->handshake_read_seq = 2;
366                 s->d1->handshake_write_seq = 1;
367                 s->d1->next_handshake_write_seq = 1;
368                 goto end;
369             }
370 
371             break;
372 
373         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
374         case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
375 
376             ret = dtls1_send_hello_verify_request(s);
377             if (ret <= 0)
378                 goto end;
379             s->state = SSL3_ST_SW_FLUSH;
380             s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
381 
382             /* HelloVerifyRequest resets Finished MAC */
383             if (s->version != DTLS1_BAD_VER)
384                 ssl3_init_finished_mac(s);
385             break;
386 
387 #ifndef OPENSSL_NO_SCTP
388         case DTLS1_SCTP_ST_SR_READ_SOCK:
389 
390             if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
391                 s->s3->in_read_app_data = 2;
392                 s->rwstate = SSL_READING;
393                 BIO_clear_retry_flags(SSL_get_rbio(s));
394                 BIO_set_retry_read(SSL_get_rbio(s));
395                 ret = -1;
396                 goto end;
397             }
398 
399             s->state = SSL3_ST_SR_FINISHED_A;
400             break;
401 
402         case DTLS1_SCTP_ST_SW_WRITE_SOCK:
403             ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
404             if (ret < 0)
405                 goto end;
406 
407             if (ret == 0) {
408                 if (s->d1->next_state != SSL_ST_OK) {
409                     s->s3->in_read_app_data = 2;
410                     s->rwstate = SSL_READING;
411                     BIO_clear_retry_flags(SSL_get_rbio(s));
412                     BIO_set_retry_read(SSL_get_rbio(s));
413                     ret = -1;
414                     goto end;
415                 }
416             }
417 
418             s->state = s->d1->next_state;
419             break;
420 #endif
421 
422         case SSL3_ST_SW_SRVR_HELLO_A:
423         case SSL3_ST_SW_SRVR_HELLO_B:
424             s->renegotiate = 2;
425             dtls1_start_timer(s);
426             ret = ssl3_send_server_hello(s);
427             if (ret <= 0)
428                 goto end;
429 
430             if (s->hit) {
431 #ifndef OPENSSL_NO_SCTP
432                 /*
433                  * Add new shared key for SCTP-Auth, will be ignored if no
434                  * SCTP used.
435                  */
436                 snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
437                          DTLS1_SCTP_AUTH_LABEL);
438 
439                 if (SSL_export_keying_material(s, sctpauthkey,
440                         sizeof(sctpauthkey), labelbuffer,
441                         sizeof(labelbuffer), NULL, 0, 0) <= 0) {
442                     ret = -1;
443                     s->state = SSL_ST_ERR;
444                     goto end;
445                 }
446 
447                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
448                          sizeof(sctpauthkey), sctpauthkey);
449 #endif
450 #ifndef OPENSSL_NO_TLSEXT
451                 if (s->tlsext_ticket_expected)
452                     s->state = SSL3_ST_SW_SESSION_TICKET_A;
453                 else
454                     s->state = SSL3_ST_SW_CHANGE_A;
455 #else
456                 s->state = SSL3_ST_SW_CHANGE_A;
457 #endif
458             } else
459                 s->state = SSL3_ST_SW_CERT_A;
460             s->init_num = 0;
461             break;
462 
463         case SSL3_ST_SW_CERT_A:
464         case SSL3_ST_SW_CERT_B:
465             /* Check if it is anon DH or normal PSK */
466             if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
467                 && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
468                 dtls1_start_timer(s);
469                 ret = ssl3_send_server_certificate(s);
470                 if (ret <= 0)
471                     goto end;
472 #ifndef OPENSSL_NO_TLSEXT
473                 if (s->tlsext_status_expected)
474                     s->state = SSL3_ST_SW_CERT_STATUS_A;
475                 else
476                     s->state = SSL3_ST_SW_KEY_EXCH_A;
477             } else {
478                 skip = 1;
479                 s->state = SSL3_ST_SW_KEY_EXCH_A;
480             }
481 #else
482             } else
483                 skip = 1;
484 
485             s->state = SSL3_ST_SW_KEY_EXCH_A;
486 #endif
487             s->init_num = 0;
488             break;
489 
490         case SSL3_ST_SW_KEY_EXCH_A:
491         case SSL3_ST_SW_KEY_EXCH_B:
492             alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
493 
494             /*
495              * clear this, it may get reset by
496              * send_server_key_exchange
497              */
498             s->s3->tmp.use_rsa_tmp = 0;
499 
500             /*
501              * only send if a DH key exchange or RSA but we have a sign only
502              * certificate
503              */
504             if (0
505                 /*
506                  * PSK: send ServerKeyExchange if PSK identity hint if
507                  * provided
508                  */
509 #ifndef OPENSSL_NO_PSK
510                 || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
511 #endif
512                 || (alg_k & SSL_kDHE)
513                 || (alg_k & SSL_kEECDH)
514                 || ((alg_k & SSL_kRSA)
515                     && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
516                         || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
517                             && EVP_PKEY_size(s->cert->pkeys
518                                              [SSL_PKEY_RSA_ENC].privatekey) *
519                             8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
520                         )
521                     )
522                 )
523                 ) {
524                 dtls1_start_timer(s);
525                 ret = ssl3_send_server_key_exchange(s);
526                 if (ret <= 0)
527                     goto end;
528             } else
529                 skip = 1;
530 
531             s->state = SSL3_ST_SW_CERT_REQ_A;
532             s->init_num = 0;
533             break;
534 
535         case SSL3_ST_SW_CERT_REQ_A:
536         case SSL3_ST_SW_CERT_REQ_B:
537             if (                /* don't request cert unless asked for it: */
538                    !(s->verify_mode & SSL_VERIFY_PEER) ||
539                    /*
540                     * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
541                     * during re-negotiation:
542                     */
543                    ((s->session->peer != NULL) &&
544                     (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
545                    /*
546                     * never request cert in anonymous ciphersuites (see
547                     * section "Certificate request" in SSL 3 drafts and in
548                     * RFC 2246):
549                     */
550                    ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
551                     /*
552                      * ... except when the application insists on
553                      * verification (against the specs, but s3_clnt.c accepts
554                      * this for SSL 3)
555                      */
556                     !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
557                    /*
558                     * never request cert in Kerberos ciphersuites
559                     */
560                    (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
561                    /*
562                     * With normal PSK Certificates and Certificate Requests
563                     * are omitted
564                     */
565                    || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
566                 /* no cert request */
567                 skip = 1;
568                 s->s3->tmp.cert_request = 0;
569                 s->state = SSL3_ST_SW_SRVR_DONE_A;
570 #ifndef OPENSSL_NO_SCTP
571                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
572                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
573                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
574                 }
575 #endif
576             } else {
577                 s->s3->tmp.cert_request = 1;
578                 dtls1_start_timer(s);
579                 ret = ssl3_send_certificate_request(s);
580                 if (ret <= 0)
581                     goto end;
582 #ifndef NETSCAPE_HANG_BUG
583                 s->state = SSL3_ST_SW_SRVR_DONE_A;
584 # ifndef OPENSSL_NO_SCTP
585                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
586                     s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
587                     s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
588                 }
589 # endif
590 #else
591                 s->state = SSL3_ST_SW_FLUSH;
592                 s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
593 # ifndef OPENSSL_NO_SCTP
594                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
595                     s->d1->next_state = s->s3->tmp.next_state;
596                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
597                 }
598 # endif
599 #endif
600                 s->init_num = 0;
601             }
602             break;
603 
604         case SSL3_ST_SW_SRVR_DONE_A:
605         case SSL3_ST_SW_SRVR_DONE_B:
606             dtls1_start_timer(s);
607             ret = ssl3_send_server_done(s);
608             if (ret <= 0)
609                 goto end;
610             s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
611             s->state = SSL3_ST_SW_FLUSH;
612             s->init_num = 0;
613             break;
614 
615         case SSL3_ST_SW_FLUSH:
616             s->rwstate = SSL_WRITING;
617             if (BIO_flush(s->wbio) <= 0) {
618                 /*
619                  * If the write error was fatal, stop trying
620                  */
621                 if (!BIO_should_retry(s->wbio)) {
622                     s->rwstate = SSL_NOTHING;
623                     s->state = s->s3->tmp.next_state;
624                 }
625 
626                 ret = -1;
627                 goto end;
628             }
629             s->rwstate = SSL_NOTHING;
630             s->state = s->s3->tmp.next_state;
631             break;
632 
633         case SSL3_ST_SR_CERT_A:
634         case SSL3_ST_SR_CERT_B:
635             if (s->s3->tmp.cert_request) {
636                 ret = ssl3_get_client_certificate(s);
637                 if (ret <= 0)
638                     goto end;
639             }
640             s->init_num = 0;
641             s->state = SSL3_ST_SR_KEY_EXCH_A;
642             break;
643 
644         case SSL3_ST_SR_KEY_EXCH_A:
645         case SSL3_ST_SR_KEY_EXCH_B:
646             ret = ssl3_get_client_key_exchange(s);
647             if (ret <= 0)
648                 goto end;
649 #ifndef OPENSSL_NO_SCTP
650             /*
651              * Add new shared key for SCTP-Auth, will be ignored if no SCTP
652              * used.
653              */
654             snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
655                      DTLS1_SCTP_AUTH_LABEL);
656 
657             if (SSL_export_keying_material(s, sctpauthkey,
658                                        sizeof(sctpauthkey), labelbuffer,
659                                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
660                 ret = -1;
661                 s->state = SSL_ST_ERR;
662                 goto end;
663             }
664 
665             BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
666                      sizeof(sctpauthkey), sctpauthkey);
667 #endif
668 
669             s->state = SSL3_ST_SR_CERT_VRFY_A;
670             s->init_num = 0;
671 
672             if (ret == 2) {
673                 /*
674                  * For the ECDH ciphersuites when the client sends its ECDH
675                  * pub key in a certificate, the CertificateVerify message is
676                  * not sent.
677                  */
678                 s->state = SSL3_ST_SR_FINISHED_A;
679                 s->init_num = 0;
680             } else if (SSL_USE_SIGALGS(s)) {
681                 s->state = SSL3_ST_SR_CERT_VRFY_A;
682                 s->init_num = 0;
683                 if (!s->session->peer)
684                     break;
685                 /*
686                  * For sigalgs freeze the handshake buffer at this point and
687                  * digest cached records.
688                  */
689                 if (!s->s3->handshake_buffer) {
690                     SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
691                     s->state = SSL_ST_ERR;
692                     return -1;
693                 }
694                 s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
695                 if (!ssl3_digest_cached_records(s)) {
696                     s->state = SSL_ST_ERR;
697                     return -1;
698                 }
699             } else {
700                 s->state = SSL3_ST_SR_CERT_VRFY_A;
701                 s->init_num = 0;
702 
703                 /*
704                  * We need to get hashes here so if there is a client cert,
705                  * it can be verified
706                  */
707                 s->method->ssl3_enc->cert_verify_mac(s,
708                                                      NID_md5,
709                                                      &(s->s3->
710                                                        tmp.cert_verify_md
711                                                        [0]));
712                 s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
713                                                      &(s->s3->
714                                                        tmp.cert_verify_md
715                                                        [MD5_DIGEST_LENGTH]));
716             }
717             break;
718 
719         case SSL3_ST_SR_CERT_VRFY_A:
720         case SSL3_ST_SR_CERT_VRFY_B:
721             ret = ssl3_get_cert_verify(s);
722             if (ret <= 0)
723                 goto end;
724 #ifndef OPENSSL_NO_SCTP
725             if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
726                 state == SSL_ST_RENEGOTIATE)
727                 s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
728             else
729 #endif
730                 s->state = SSL3_ST_SR_FINISHED_A;
731             s->init_num = 0;
732             break;
733 
734         case SSL3_ST_SR_FINISHED_A:
735         case SSL3_ST_SR_FINISHED_B:
736             /*
737              * Enable CCS. Receiving a CCS clears the flag, so make
738              * sure not to re-enable it to ban duplicates. This *should* be the
739              * first time we have received one - but we check anyway to be
740              * cautious.
741              * s->s3->change_cipher_spec is set when a CCS is
742              * processed in d1_pkt.c, and remains set until
743              * the client's Finished message is read.
744              */
745             if (!s->s3->change_cipher_spec)
746                 s->d1->change_cipher_spec_ok = 1;
747             ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
748                                     SSL3_ST_SR_FINISHED_B);
749             if (ret <= 0)
750                 goto end;
751             dtls1_stop_timer(s);
752             if (s->hit)
753                 s->state = SSL_ST_OK;
754 #ifndef OPENSSL_NO_TLSEXT
755             else if (s->tlsext_ticket_expected)
756                 s->state = SSL3_ST_SW_SESSION_TICKET_A;
757 #endif
758             else
759                 s->state = SSL3_ST_SW_CHANGE_A;
760             s->init_num = 0;
761             break;
762 
763 #ifndef OPENSSL_NO_TLSEXT
764         case SSL3_ST_SW_SESSION_TICKET_A:
765         case SSL3_ST_SW_SESSION_TICKET_B:
766             ret = ssl3_send_newsession_ticket(s);
767             if (ret <= 0)
768                 goto end;
769             s->state = SSL3_ST_SW_CHANGE_A;
770             s->init_num = 0;
771             break;
772 
773         case SSL3_ST_SW_CERT_STATUS_A:
774         case SSL3_ST_SW_CERT_STATUS_B:
775             ret = ssl3_send_cert_status(s);
776             if (ret <= 0)
777                 goto end;
778             s->state = SSL3_ST_SW_KEY_EXCH_A;
779             s->init_num = 0;
780             break;
781 
782 #endif
783 
784         case SSL3_ST_SW_CHANGE_A:
785         case SSL3_ST_SW_CHANGE_B:
786 
787             s->session->cipher = s->s3->tmp.new_cipher;
788             if (!s->method->ssl3_enc->setup_key_block(s)) {
789                 ret = -1;
790                 s->state = SSL_ST_ERR;
791                 goto end;
792             }
793 
794             ret = dtls1_send_change_cipher_spec(s,
795                                                 SSL3_ST_SW_CHANGE_A,
796                                                 SSL3_ST_SW_CHANGE_B);
797 
798             if (ret <= 0)
799                 goto end;
800 
801 #ifndef OPENSSL_NO_SCTP
802             if (!s->hit) {
803                 /*
804                  * Change to new shared key of SCTP-Auth, will be ignored if
805                  * no SCTP used.
806                  */
807                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
808                          0, NULL);
809             }
810 #endif
811 
812             s->state = SSL3_ST_SW_FINISHED_A;
813             s->init_num = 0;
814 
815             if (!s->method->ssl3_enc->change_cipher_state(s,
816                                                           SSL3_CHANGE_CIPHER_SERVER_WRITE))
817             {
818                 ret = -1;
819                 s->state = SSL_ST_ERR;
820                 goto end;
821             }
822 
823             dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
824             break;
825 
826         case SSL3_ST_SW_FINISHED_A:
827         case SSL3_ST_SW_FINISHED_B:
828             ret = ssl3_send_finished(s,
829                                      SSL3_ST_SW_FINISHED_A,
830                                      SSL3_ST_SW_FINISHED_B,
831                                      s->method->
832                                      ssl3_enc->server_finished_label,
833                                      s->method->
834                                      ssl3_enc->server_finished_label_len);
835             if (ret <= 0)
836                 goto end;
837             s->state = SSL3_ST_SW_FLUSH;
838             if (s->hit) {
839                 s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
840 
841 #ifndef OPENSSL_NO_SCTP
842                 /*
843                  * Change to new shared key of SCTP-Auth, will be ignored if
844                  * no SCTP used.
845                  */
846                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
847                          0, NULL);
848 #endif
849             } else {
850                 s->s3->tmp.next_state = SSL_ST_OK;
851 #ifndef OPENSSL_NO_SCTP
852                 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
853                     s->d1->next_state = s->s3->tmp.next_state;
854                     s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
855                 }
856 #endif
857             }
858             s->init_num = 0;
859             break;
860 
861         case SSL_ST_OK:
862             /* clean a few things up */
863             ssl3_cleanup_key_block(s);
864 
865 #if 0
866             BUF_MEM_free(s->init_buf);
867             s->init_buf = NULL;
868 #endif
869 
870             /* remove buffering on output */
871             ssl_free_wbio_buffer(s);
872 
873             s->init_num = 0;
874 
875             if (s->renegotiate == 2) { /* skipped if we just sent a
876                                         * HelloRequest */
877                 s->renegotiate = 0;
878                 s->new_session = 0;
879 
880                 ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
881 
882                 s->ctx->stats.sess_accept_good++;
883                 /* s->server=1; */
884                 s->handshake_func = dtls1_accept;
885 
886                 if (cb != NULL)
887                     cb(s, SSL_CB_HANDSHAKE_DONE, 1);
888             }
889 
890             ret = 1;
891 
892             /* done handshaking, next message is client hello */
893             s->d1->handshake_read_seq = 0;
894             /* next message is server hello */
895             s->d1->handshake_write_seq = 0;
896             s->d1->next_handshake_write_seq = 0;
897             dtls1_clear_received_buffer(s);
898             goto end;
899             /* break; */
900 
901         case SSL_ST_ERR:
902         default:
903             SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
904             ret = -1;
905             goto end;
906             /* break; */
907         }
908 
909         if (!s->s3->tmp.reuse_message && !skip) {
910             if (s->debug) {
911                 if ((ret = BIO_flush(s->wbio)) <= 0)
912                     goto end;
913             }
914 
915             if ((cb != NULL) && (s->state != state)) {
916                 new_state = s->state;
917                 s->state = state;
918                 cb(s, SSL_CB_ACCEPT_LOOP, 1);
919                 s->state = new_state;
920             }
921         }
922         skip = 0;
923     }
924  end:
925     /* BIO_flush(s->wbio); */
926 
927     s->in_handshake--;
928 #ifndef OPENSSL_NO_SCTP
929     /*
930      * Notify SCTP BIO socket to leave handshake mode and prevent stream
931      * identifier other than 0. Will be ignored if no SCTP is used.
932      */
933     BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
934              s->in_handshake, NULL);
935 #endif
936 
937     if (cb != NULL)
938         cb(s, SSL_CB_ACCEPT_EXIT, ret);
939     return (ret);
940 }
941 
dtls1_send_hello_verify_request(SSL * s)942 int dtls1_send_hello_verify_request(SSL *s)
943 {
944     unsigned int msg_len;
945     unsigned char *msg, *buf, *p;
946 
947     if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
948         buf = (unsigned char *)s->init_buf->data;
949 
950         msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
951         /* Always use DTLS 1.0 version: see RFC 6347 */
952         *(p++) = DTLS1_VERSION >> 8;
953         *(p++) = DTLS1_VERSION & 0xFF;
954 
955         if (s->ctx->app_gen_cookie_cb == NULL ||
956             s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
957                                       &(s->d1->cookie_len)) == 0) {
958             SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
959                    ERR_R_INTERNAL_ERROR);
960             s->state = SSL_ST_ERR;
961             return 0;
962         }
963 
964         *(p++) = (unsigned char)s->d1->cookie_len;
965         memcpy(p, s->d1->cookie, s->d1->cookie_len);
966         p += s->d1->cookie_len;
967         msg_len = p - msg;
968 
969         dtls1_set_message_header(s, buf,
970                                  DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
971                                  msg_len);
972 
973         s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
974         /* number of bytes to write */
975         s->init_num = p - buf;
976         s->init_off = 0;
977     }
978 
979     /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
980     return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
981 }
982