d1_srvr.c revision 325335
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
129static const SSL_METHOD *dtls1_get_server_method(int ver);
130static int dtls1_send_hello_verify_request(SSL *s);
131
132static 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
144IMPLEMENT_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
150IMPLEMENT_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
156IMPLEMENT_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
162int 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                if (!ssl3_init_finished_mac(s)) {
286                    ret = -1;
287                    s->state = SSL_ST_ERR;
288                    goto end;
289                }
290
291                s->state = SSL3_ST_SR_CLNT_HELLO_A;
292                s->ctx->stats.sess_accept++;
293            } else if (!s->s3->send_connection_binding &&
294                       !(s->options &
295                         SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION)) {
296                /*
297                 * Server attempting to renegotiate with client that doesn't
298                 * support secure renegotiation.
299                 */
300                SSLerr(SSL_F_DTLS1_ACCEPT,
301                       SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
302                ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_HANDSHAKE_FAILURE);
303                ret = -1;
304                s->state = SSL_ST_ERR;
305                goto end;
306            } else {
307                /*
308                 * s->state == SSL_ST_RENEGOTIATE, we will just send a
309                 * HelloRequest
310                 */
311                s->ctx->stats.sess_accept_renegotiate++;
312                s->state = SSL3_ST_SW_HELLO_REQ_A;
313            }
314
315            break;
316
317        case SSL3_ST_SW_HELLO_REQ_A:
318        case SSL3_ST_SW_HELLO_REQ_B:
319
320            s->shutdown = 0;
321            dtls1_clear_sent_buffer(s);
322            dtls1_start_timer(s);
323            ret = ssl3_send_hello_request(s);
324            if (ret <= 0)
325                goto end;
326            s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
327            s->state = SSL3_ST_SW_FLUSH;
328            s->init_num = 0;
329
330            if (!ssl3_init_finished_mac(s)) {
331                ret = -1;
332                s->state = SSL_ST_ERR;
333                goto end;
334            }
335            break;
336
337        case SSL3_ST_SW_HELLO_REQ_C:
338            s->state = SSL_ST_OK;
339            break;
340
341        case SSL3_ST_SR_CLNT_HELLO_A:
342        case SSL3_ST_SR_CLNT_HELLO_B:
343        case SSL3_ST_SR_CLNT_HELLO_C:
344
345            s->shutdown = 0;
346            ret = ssl3_get_client_hello(s);
347            if (ret <= 0)
348                goto end;
349            dtls1_stop_timer(s);
350
351            if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
352                s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
353            else
354                s->state = SSL3_ST_SW_SRVR_HELLO_A;
355
356            s->init_num = 0;
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                if (!ssl3_init_finished_mac(s)) {
385                    ret = -1;
386                    s->state = SSL_ST_ERR;
387                    goto end;
388                }
389            break;
390
391#ifndef OPENSSL_NO_SCTP
392        case DTLS1_SCTP_ST_SR_READ_SOCK:
393
394            if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
395                s->s3->in_read_app_data = 2;
396                s->rwstate = SSL_READING;
397                BIO_clear_retry_flags(SSL_get_rbio(s));
398                BIO_set_retry_read(SSL_get_rbio(s));
399                ret = -1;
400                goto end;
401            }
402
403            s->state = SSL3_ST_SR_FINISHED_A;
404            break;
405
406        case DTLS1_SCTP_ST_SW_WRITE_SOCK:
407            ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
408            if (ret < 0)
409                goto end;
410
411            if (ret == 0) {
412                if (s->d1->next_state != SSL_ST_OK) {
413                    s->s3->in_read_app_data = 2;
414                    s->rwstate = SSL_READING;
415                    BIO_clear_retry_flags(SSL_get_rbio(s));
416                    BIO_set_retry_read(SSL_get_rbio(s));
417                    ret = -1;
418                    goto end;
419                }
420            }
421
422            s->state = s->d1->next_state;
423            break;
424#endif
425
426        case SSL3_ST_SW_SRVR_HELLO_A:
427        case SSL3_ST_SW_SRVR_HELLO_B:
428            s->renegotiate = 2;
429            dtls1_start_timer(s);
430            ret = ssl3_send_server_hello(s);
431            if (ret <= 0)
432                goto end;
433
434            if (s->hit) {
435#ifndef OPENSSL_NO_SCTP
436                /*
437                 * Add new shared key for SCTP-Auth, will be ignored if no
438                 * SCTP used.
439                 */
440                snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
441                         DTLS1_SCTP_AUTH_LABEL);
442
443                if (SSL_export_keying_material(s, sctpauthkey,
444                        sizeof(sctpauthkey), labelbuffer,
445                        sizeof(labelbuffer), NULL, 0, 0) <= 0) {
446                    ret = -1;
447                    s->state = SSL_ST_ERR;
448                    goto end;
449                }
450
451                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
452                         sizeof(sctpauthkey), sctpauthkey);
453#endif
454#ifndef OPENSSL_NO_TLSEXT
455                if (s->tlsext_ticket_expected)
456                    s->state = SSL3_ST_SW_SESSION_TICKET_A;
457                else
458                    s->state = SSL3_ST_SW_CHANGE_A;
459#else
460                s->state = SSL3_ST_SW_CHANGE_A;
461#endif
462            } else
463                s->state = SSL3_ST_SW_CERT_A;
464            s->init_num = 0;
465            break;
466
467        case SSL3_ST_SW_CERT_A:
468        case SSL3_ST_SW_CERT_B:
469            /* Check if it is anon DH or normal PSK */
470            if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
471                && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
472                dtls1_start_timer(s);
473                ret = ssl3_send_server_certificate(s);
474                if (ret <= 0)
475                    goto end;
476#ifndef OPENSSL_NO_TLSEXT
477                if (s->tlsext_status_expected)
478                    s->state = SSL3_ST_SW_CERT_STATUS_A;
479                else
480                    s->state = SSL3_ST_SW_KEY_EXCH_A;
481            } else {
482                skip = 1;
483                s->state = SSL3_ST_SW_KEY_EXCH_A;
484            }
485#else
486            } else
487                skip = 1;
488
489            s->state = SSL3_ST_SW_KEY_EXCH_A;
490#endif
491            s->init_num = 0;
492            break;
493
494        case SSL3_ST_SW_KEY_EXCH_A:
495        case SSL3_ST_SW_KEY_EXCH_B:
496            alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
497
498            /*
499             * clear this, it may get reset by
500             * send_server_key_exchange
501             */
502            s->s3->tmp.use_rsa_tmp = 0;
503
504            /*
505             * only send if a DH key exchange or RSA but we have a sign only
506             * certificate
507             */
508            if (0
509                /*
510                 * PSK: send ServerKeyExchange if PSK identity hint if
511                 * provided
512                 */
513#ifndef OPENSSL_NO_PSK
514                || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
515#endif
516                || (alg_k & SSL_kDHE)
517                || (alg_k & SSL_kEECDH)
518                || ((alg_k & SSL_kRSA)
519                    && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
520                        || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
521                            && EVP_PKEY_size(s->cert->pkeys
522                                             [SSL_PKEY_RSA_ENC].privatekey) *
523                            8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
524                        )
525                    )
526                )
527                ) {
528                dtls1_start_timer(s);
529                ret = ssl3_send_server_key_exchange(s);
530                if (ret <= 0)
531                    goto end;
532            } else
533                skip = 1;
534
535            s->state = SSL3_ST_SW_CERT_REQ_A;
536            s->init_num = 0;
537            break;
538
539        case SSL3_ST_SW_CERT_REQ_A:
540        case SSL3_ST_SW_CERT_REQ_B:
541            if (                /* don't request cert unless asked for it: */
542                   !(s->verify_mode & SSL_VERIFY_PEER) ||
543                   /*
544                    * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
545                    * during re-negotiation:
546                    */
547                   ((s->session->peer != NULL) &&
548                    (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
549                   /*
550                    * never request cert in anonymous ciphersuites (see
551                    * section "Certificate request" in SSL 3 drafts and in
552                    * RFC 2246):
553                    */
554                   ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
555                    /*
556                     * ... except when the application insists on
557                     * verification (against the specs, but s3_clnt.c accepts
558                     * this for SSL 3)
559                     */
560                    !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
561                   /*
562                    * never request cert in Kerberos ciphersuites
563                    */
564                   (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
565                   /*
566                    * With normal PSK Certificates and Certificate Requests
567                    * are omitted
568                    */
569                   || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
570                /* no cert request */
571                skip = 1;
572                s->s3->tmp.cert_request = 0;
573                s->state = SSL3_ST_SW_SRVR_DONE_A;
574#ifndef OPENSSL_NO_SCTP
575                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
576                    s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
577                    s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
578                }
579#endif
580            } else {
581                s->s3->tmp.cert_request = 1;
582                dtls1_start_timer(s);
583                ret = ssl3_send_certificate_request(s);
584                if (ret <= 0)
585                    goto end;
586#ifndef NETSCAPE_HANG_BUG
587                s->state = SSL3_ST_SW_SRVR_DONE_A;
588# ifndef OPENSSL_NO_SCTP
589                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
590                    s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
591                    s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
592                }
593# endif
594#else
595                s->state = SSL3_ST_SW_FLUSH;
596                s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
597# ifndef OPENSSL_NO_SCTP
598                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
599                    s->d1->next_state = s->s3->tmp.next_state;
600                    s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
601                }
602# endif
603#endif
604                s->init_num = 0;
605            }
606            break;
607
608        case SSL3_ST_SW_SRVR_DONE_A:
609        case SSL3_ST_SW_SRVR_DONE_B:
610            dtls1_start_timer(s);
611            ret = ssl3_send_server_done(s);
612            if (ret <= 0)
613                goto end;
614            s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
615            s->state = SSL3_ST_SW_FLUSH;
616            s->init_num = 0;
617            break;
618
619        case SSL3_ST_SW_FLUSH:
620            s->rwstate = SSL_WRITING;
621            if (BIO_flush(s->wbio) <= 0) {
622                /*
623                 * If the write error was fatal, stop trying
624                 */
625                if (!BIO_should_retry(s->wbio)) {
626                    s->rwstate = SSL_NOTHING;
627                    s->state = s->s3->tmp.next_state;
628                }
629
630                ret = -1;
631                goto end;
632            }
633            s->rwstate = SSL_NOTHING;
634            s->state = s->s3->tmp.next_state;
635            break;
636
637        case SSL3_ST_SR_CERT_A:
638        case SSL3_ST_SR_CERT_B:
639            if (s->s3->tmp.cert_request) {
640                ret = ssl3_get_client_certificate(s);
641                if (ret <= 0)
642                    goto end;
643            }
644            s->init_num = 0;
645            s->state = SSL3_ST_SR_KEY_EXCH_A;
646            break;
647
648        case SSL3_ST_SR_KEY_EXCH_A:
649        case SSL3_ST_SR_KEY_EXCH_B:
650            ret = ssl3_get_client_key_exchange(s);
651            if (ret <= 0)
652                goto end;
653#ifndef OPENSSL_NO_SCTP
654            /*
655             * Add new shared key for SCTP-Auth, will be ignored if no SCTP
656             * used.
657             */
658            snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
659                     DTLS1_SCTP_AUTH_LABEL);
660
661            if (SSL_export_keying_material(s, sctpauthkey,
662                                       sizeof(sctpauthkey), labelbuffer,
663                                       sizeof(labelbuffer), NULL, 0, 0) <= 0) {
664                ret = -1;
665                s->state = SSL_ST_ERR;
666                goto end;
667            }
668
669            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
670                     sizeof(sctpauthkey), sctpauthkey);
671#endif
672
673            s->state = SSL3_ST_SR_CERT_VRFY_A;
674            s->init_num = 0;
675
676            if (ret == 2) {
677                /*
678                 * For the ECDH ciphersuites when the client sends its ECDH
679                 * pub key in a certificate, the CertificateVerify message is
680                 * not sent.
681                 */
682                s->state = SSL3_ST_SR_FINISHED_A;
683                s->init_num = 0;
684            } else if (SSL_USE_SIGALGS(s)) {
685                s->state = SSL3_ST_SR_CERT_VRFY_A;
686                s->init_num = 0;
687                if (!s->session->peer)
688                    break;
689                /*
690                 * For sigalgs freeze the handshake buffer at this point and
691                 * digest cached records.
692                 */
693                if (!s->s3->handshake_buffer) {
694                    SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
695                    s->state = SSL_ST_ERR;
696                    return -1;
697                }
698                s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
699                if (!ssl3_digest_cached_records(s)) {
700                    s->state = SSL_ST_ERR;
701                    return -1;
702                }
703            } else {
704                s->state = SSL3_ST_SR_CERT_VRFY_A;
705                s->init_num = 0;
706
707                /*
708                 * We need to get hashes here so if there is a client cert,
709                 * it can be verified
710                 */
711                s->method->ssl3_enc->cert_verify_mac(s,
712                                                     NID_md5,
713                                                     &(s->s3->
714                                                       tmp.cert_verify_md
715                                                       [0]));
716                s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
717                                                     &(s->s3->
718                                                       tmp.cert_verify_md
719                                                       [MD5_DIGEST_LENGTH]));
720            }
721            break;
722
723        case SSL3_ST_SR_CERT_VRFY_A:
724        case SSL3_ST_SR_CERT_VRFY_B:
725            ret = ssl3_get_cert_verify(s);
726            if (ret <= 0)
727                goto end;
728#ifndef OPENSSL_NO_SCTP
729            if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
730                state == SSL_ST_RENEGOTIATE)
731                s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
732            else
733#endif
734                s->state = SSL3_ST_SR_FINISHED_A;
735            s->init_num = 0;
736            break;
737
738        case SSL3_ST_SR_FINISHED_A:
739        case SSL3_ST_SR_FINISHED_B:
740            /*
741             * Enable CCS. Receiving a CCS clears the flag, so make
742             * sure not to re-enable it to ban duplicates. This *should* be the
743             * first time we have received one - but we check anyway to be
744             * cautious.
745             * s->s3->change_cipher_spec is set when a CCS is
746             * processed in d1_pkt.c, and remains set until
747             * the client's Finished message is read.
748             */
749            if (!s->s3->change_cipher_spec)
750                s->d1->change_cipher_spec_ok = 1;
751            ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
752                                    SSL3_ST_SR_FINISHED_B);
753            if (ret <= 0)
754                goto end;
755            dtls1_stop_timer(s);
756            if (s->hit)
757                s->state = SSL_ST_OK;
758#ifndef OPENSSL_NO_TLSEXT
759            else if (s->tlsext_ticket_expected)
760                s->state = SSL3_ST_SW_SESSION_TICKET_A;
761#endif
762            else
763                s->state = SSL3_ST_SW_CHANGE_A;
764            s->init_num = 0;
765            break;
766
767#ifndef OPENSSL_NO_TLSEXT
768        case SSL3_ST_SW_SESSION_TICKET_A:
769        case SSL3_ST_SW_SESSION_TICKET_B:
770            ret = ssl3_send_newsession_ticket(s);
771            if (ret <= 0)
772                goto end;
773            s->state = SSL3_ST_SW_CHANGE_A;
774            s->init_num = 0;
775            break;
776
777        case SSL3_ST_SW_CERT_STATUS_A:
778        case SSL3_ST_SW_CERT_STATUS_B:
779            ret = ssl3_send_cert_status(s);
780            if (ret <= 0)
781                goto end;
782            s->state = SSL3_ST_SW_KEY_EXCH_A;
783            s->init_num = 0;
784            break;
785
786#endif
787
788        case SSL3_ST_SW_CHANGE_A:
789        case SSL3_ST_SW_CHANGE_B:
790
791            s->session->cipher = s->s3->tmp.new_cipher;
792            if (!s->method->ssl3_enc->setup_key_block(s)) {
793                ret = -1;
794                s->state = SSL_ST_ERR;
795                goto end;
796            }
797
798            ret = dtls1_send_change_cipher_spec(s,
799                                                SSL3_ST_SW_CHANGE_A,
800                                                SSL3_ST_SW_CHANGE_B);
801
802            if (ret <= 0)
803                goto end;
804
805#ifndef OPENSSL_NO_SCTP
806            if (!s->hit) {
807                /*
808                 * Change to new shared key of SCTP-Auth, will be ignored if
809                 * no SCTP used.
810                 */
811                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
812                         0, NULL);
813            }
814#endif
815
816            s->state = SSL3_ST_SW_FINISHED_A;
817            s->init_num = 0;
818
819            if (!s->method->ssl3_enc->change_cipher_state(s,
820                                                          SSL3_CHANGE_CIPHER_SERVER_WRITE))
821            {
822                ret = -1;
823                s->state = SSL_ST_ERR;
824                goto end;
825            }
826
827            dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
828            break;
829
830        case SSL3_ST_SW_FINISHED_A:
831        case SSL3_ST_SW_FINISHED_B:
832            ret = ssl3_send_finished(s,
833                                     SSL3_ST_SW_FINISHED_A,
834                                     SSL3_ST_SW_FINISHED_B,
835                                     s->method->
836                                     ssl3_enc->server_finished_label,
837                                     s->method->
838                                     ssl3_enc->server_finished_label_len);
839            if (ret <= 0)
840                goto end;
841            s->state = SSL3_ST_SW_FLUSH;
842            if (s->hit) {
843                s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
844
845#ifndef OPENSSL_NO_SCTP
846                /*
847                 * Change to new shared key of SCTP-Auth, will be ignored if
848                 * no SCTP used.
849                 */
850                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
851                         0, NULL);
852#endif
853            } else {
854                s->s3->tmp.next_state = SSL_ST_OK;
855#ifndef OPENSSL_NO_SCTP
856                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
857                    s->d1->next_state = s->s3->tmp.next_state;
858                    s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
859                }
860#endif
861            }
862            s->init_num = 0;
863            break;
864
865        case SSL_ST_OK:
866            /* clean a few things up */
867            ssl3_cleanup_key_block(s);
868
869#if 0
870            BUF_MEM_free(s->init_buf);
871            s->init_buf = NULL;
872#endif
873
874            /* remove buffering on output */
875            ssl_free_wbio_buffer(s);
876
877            s->init_num = 0;
878
879            if (s->renegotiate == 2) { /* skipped if we just sent a
880                                        * HelloRequest */
881                s->renegotiate = 0;
882                s->new_session = 0;
883
884                ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
885
886                s->ctx->stats.sess_accept_good++;
887                /* s->server=1; */
888                s->handshake_func = dtls1_accept;
889
890                if (cb != NULL)
891                    cb(s, SSL_CB_HANDSHAKE_DONE, 1);
892            }
893
894            ret = 1;
895
896            /* done handshaking, next message is client hello */
897            s->d1->handshake_read_seq = 0;
898            /* next message is server hello */
899            s->d1->handshake_write_seq = 0;
900            s->d1->next_handshake_write_seq = 0;
901            dtls1_clear_received_buffer(s);
902            goto end;
903            /* break; */
904
905        case SSL_ST_ERR:
906        default:
907            SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
908            ret = -1;
909            goto end;
910            /* break; */
911        }
912
913        if (!s->s3->tmp.reuse_message && !skip) {
914            if (s->debug) {
915                if ((ret = BIO_flush(s->wbio)) <= 0)
916                    goto end;
917            }
918
919            if ((cb != NULL) && (s->state != state)) {
920                new_state = s->state;
921                s->state = state;
922                cb(s, SSL_CB_ACCEPT_LOOP, 1);
923                s->state = new_state;
924            }
925        }
926        skip = 0;
927    }
928 end:
929    /* BIO_flush(s->wbio); */
930
931    s->in_handshake--;
932#ifndef OPENSSL_NO_SCTP
933    /*
934     * Notify SCTP BIO socket to leave handshake mode and prevent stream
935     * identifier other than 0. Will be ignored if no SCTP is used.
936     */
937    BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
938             s->in_handshake, NULL);
939#endif
940
941    if (cb != NULL)
942        cb(s, SSL_CB_ACCEPT_EXIT, ret);
943    return (ret);
944}
945
946int dtls1_send_hello_verify_request(SSL *s)
947{
948    unsigned int msg_len;
949    unsigned char *msg, *buf, *p;
950
951    if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
952        buf = (unsigned char *)s->init_buf->data;
953
954        msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
955        /* Always use DTLS 1.0 version: see RFC 6347 */
956        *(p++) = DTLS1_VERSION >> 8;
957        *(p++) = DTLS1_VERSION & 0xFF;
958
959        if (s->ctx->app_gen_cookie_cb == NULL ||
960            s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
961                                      &(s->d1->cookie_len)) == 0) {
962            SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
963                   ERR_R_INTERNAL_ERROR);
964            s->state = SSL_ST_ERR;
965            return 0;
966        }
967
968        *(p++) = (unsigned char)s->d1->cookie_len;
969        memcpy(p, s->d1->cookie, s->d1->cookie_len);
970        p += s->d1->cookie_len;
971        msg_len = p - msg;
972
973        dtls1_set_message_header(s, buf,
974                                 DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
975                                 msg_len);
976
977        s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
978        /* number of bytes to write */
979        s->init_num = p - buf;
980        s->init_off = 0;
981    }
982
983    /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
984    return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
985}
986