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 == DTLS1_VERSION)
135        return (DTLSv1_server_method());
136    else if (ver == DTLS1_2_VERSION)
137        return (DTLSv1_2_server_method());
138    else
139        return (NULL);
140}
141
142IMPLEMENT_dtls1_meth_func(DTLS1_VERSION,
143                          DTLSv1_server_method,
144                          dtls1_accept,
145                          ssl_undefined_function,
146                          dtls1_get_server_method, DTLSv1_enc_data)
147
148    IMPLEMENT_dtls1_meth_func(DTLS1_2_VERSION,
149                          DTLSv1_2_server_method,
150                          dtls1_accept,
151                          ssl_undefined_function,
152                          dtls1_get_server_method, DTLSv1_2_enc_data)
153
154    IMPLEMENT_dtls1_meth_func(DTLS_ANY_VERSION,
155                          DTLS_server_method,
156                          dtls1_accept,
157                          ssl_undefined_function,
158                          dtls1_get_server_method, DTLSv1_2_enc_data)
159
160int dtls1_accept(SSL *s)
161{
162    BUF_MEM *buf;
163    unsigned long Time = (unsigned long)time(NULL);
164    void (*cb) (const SSL *ssl, int type, int val) = NULL;
165    unsigned long alg_k;
166    int ret = -1;
167    int new_state, state, skip = 0;
168    int listen;
169#ifndef OPENSSL_NO_SCTP
170    unsigned char sctpauthkey[64];
171    char labelbuffer[sizeof(DTLS1_SCTP_AUTH_LABEL)];
172#endif
173
174    RAND_add(&Time, sizeof(Time), 0);
175    ERR_clear_error();
176    clear_sys_error();
177
178    if (s->info_callback != NULL)
179        cb = s->info_callback;
180    else if (s->ctx->info_callback != NULL)
181        cb = s->ctx->info_callback;
182
183    listen = s->d1->listen;
184
185    /* init things to blank */
186    s->in_handshake++;
187    if (!SSL_in_init(s) || SSL_in_before(s))
188        SSL_clear(s);
189
190    s->d1->listen = listen;
191#ifndef OPENSSL_NO_SCTP
192    /*
193     * Notify SCTP BIO socket to enter handshake mode and prevent stream
194     * identifier other than 0. Will be ignored if no SCTP is used.
195     */
196    BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
197             s->in_handshake, NULL);
198#endif
199
200    if (s->cert == NULL) {
201        SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_NO_CERTIFICATE_SET);
202        return (-1);
203    }
204#ifndef OPENSSL_NO_HEARTBEATS
205    /*
206     * If we're awaiting a HeartbeatResponse, pretend we already got and
207     * don't await it anymore, because Heartbeats don't make sense during
208     * handshakes anyway.
209     */
210    if (s->tlsext_hb_pending) {
211        dtls1_stop_timer(s);
212        s->tlsext_hb_pending = 0;
213        s->tlsext_hb_seq++;
214    }
215#endif
216
217    for (;;) {
218        state = s->state;
219
220        switch (s->state) {
221        case SSL_ST_RENEGOTIATE:
222            s->renegotiate = 1;
223            /* s->state=SSL_ST_ACCEPT; */
224
225        case SSL_ST_BEFORE:
226        case SSL_ST_ACCEPT:
227        case SSL_ST_BEFORE | SSL_ST_ACCEPT:
228        case SSL_ST_OK | SSL_ST_ACCEPT:
229
230            s->server = 1;
231            if (cb != NULL)
232                cb(s, SSL_CB_HANDSHAKE_START, 1);
233
234            if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
235                SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
236                return -1;
237            }
238            s->type = SSL_ST_ACCEPT;
239
240            if (s->init_buf == NULL) {
241                if ((buf = BUF_MEM_new()) == NULL) {
242                    ret = -1;
243                    s->state = SSL_ST_ERR;
244                    goto end;
245                }
246                if (!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
247                    BUF_MEM_free(buf);
248                    ret = -1;
249                    s->state = SSL_ST_ERR;
250                    goto end;
251                }
252                s->init_buf = buf;
253            }
254
255            if (!ssl3_setup_buffers(s)) {
256                ret = -1;
257                s->state = SSL_ST_ERR;
258                goto end;
259            }
260
261            s->init_num = 0;
262            s->d1->change_cipher_spec_ok = 0;
263            /*
264             * Should have been reset by ssl3_get_finished, too.
265             */
266            s->s3->change_cipher_spec = 0;
267
268            if (s->state != SSL_ST_RENEGOTIATE) {
269                /*
270                 * Ok, we now need to push on a buffering BIO so that the
271                 * output is sent in a way that TCP likes :-) ...but not with
272                 * SCTP :-)
273                 */
274#ifndef OPENSSL_NO_SCTP
275                if (!BIO_dgram_is_sctp(SSL_get_wbio(s)))
276#endif
277                    if (!ssl_init_wbio_buffer(s, 1)) {
278                        ret = -1;
279                        s->state = SSL_ST_ERR;
280                        goto end;
281                    }
282
283                ssl3_init_finished_mac(s);
284                s->state = SSL3_ST_SR_CLNT_HELLO_A;
285                s->ctx->stats.sess_accept++;
286            } else {
287                /*
288                 * s->state == SSL_ST_RENEGOTIATE, we will just send a
289                 * HelloRequest
290                 */
291                s->ctx->stats.sess_accept_renegotiate++;
292                s->state = SSL3_ST_SW_HELLO_REQ_A;
293            }
294
295            break;
296
297        case SSL3_ST_SW_HELLO_REQ_A:
298        case SSL3_ST_SW_HELLO_REQ_B:
299
300            s->shutdown = 0;
301            dtls1_clear_record_buffer(s);
302            dtls1_start_timer(s);
303            ret = ssl3_send_hello_request(s);
304            if (ret <= 0)
305                goto end;
306            s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
307            s->state = SSL3_ST_SW_FLUSH;
308            s->init_num = 0;
309
310            ssl3_init_finished_mac(s);
311            break;
312
313        case SSL3_ST_SW_HELLO_REQ_C:
314            s->state = SSL_ST_OK;
315            break;
316
317        case SSL3_ST_SR_CLNT_HELLO_A:
318        case SSL3_ST_SR_CLNT_HELLO_B:
319        case SSL3_ST_SR_CLNT_HELLO_C:
320
321            s->shutdown = 0;
322            ret = ssl3_get_client_hello(s);
323            if (ret <= 0)
324                goto end;
325            dtls1_stop_timer(s);
326
327            if (ret == 1 && (SSL_get_options(s) & SSL_OP_COOKIE_EXCHANGE))
328                s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A;
329            else
330                s->state = SSL3_ST_SW_SRVR_HELLO_A;
331
332            s->init_num = 0;
333
334            /*
335             * Reflect ClientHello sequence to remain stateless while
336             * listening
337             */
338            if (listen) {
339                memcpy(s->s3->write_sequence, s->s3->read_sequence,
340                       sizeof(s->s3->write_sequence));
341            }
342
343            /* If we're just listening, stop here */
344            if (listen && s->state == SSL3_ST_SW_SRVR_HELLO_A) {
345                ret = 2;
346                s->d1->listen = 0;
347                /*
348                 * Set expected sequence numbers to continue the handshake.
349                 */
350                s->d1->handshake_read_seq = 2;
351                s->d1->handshake_write_seq = 1;
352                s->d1->next_handshake_write_seq = 1;
353                goto end;
354            }
355
356            break;
357
358        case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A:
359        case DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B:
360
361            ret = dtls1_send_hello_verify_request(s);
362            if (ret <= 0)
363                goto end;
364            s->state = SSL3_ST_SW_FLUSH;
365            s->s3->tmp.next_state = SSL3_ST_SR_CLNT_HELLO_A;
366
367            /* HelloVerifyRequest resets Finished MAC */
368            if (s->version != DTLS1_BAD_VER)
369                ssl3_init_finished_mac(s);
370            break;
371
372#ifndef OPENSSL_NO_SCTP
373        case DTLS1_SCTP_ST_SR_READ_SOCK:
374
375            if (BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
376                s->s3->in_read_app_data = 2;
377                s->rwstate = SSL_READING;
378                BIO_clear_retry_flags(SSL_get_rbio(s));
379                BIO_set_retry_read(SSL_get_rbio(s));
380                ret = -1;
381                goto end;
382            }
383
384            s->state = SSL3_ST_SR_FINISHED_A;
385            break;
386
387        case DTLS1_SCTP_ST_SW_WRITE_SOCK:
388            ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
389            if (ret < 0)
390                goto end;
391
392            if (ret == 0) {
393                if (s->d1->next_state != SSL_ST_OK) {
394                    s->s3->in_read_app_data = 2;
395                    s->rwstate = SSL_READING;
396                    BIO_clear_retry_flags(SSL_get_rbio(s));
397                    BIO_set_retry_read(SSL_get_rbio(s));
398                    ret = -1;
399                    goto end;
400                }
401            }
402
403            s->state = s->d1->next_state;
404            break;
405#endif
406
407        case SSL3_ST_SW_SRVR_HELLO_A:
408        case SSL3_ST_SW_SRVR_HELLO_B:
409            s->renegotiate = 2;
410            dtls1_start_timer(s);
411            ret = ssl3_send_server_hello(s);
412            if (ret <= 0)
413                goto end;
414
415            if (s->hit) {
416#ifndef OPENSSL_NO_SCTP
417                /*
418                 * Add new shared key for SCTP-Auth, will be ignored if no
419                 * SCTP used.
420                 */
421                snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
422                         DTLS1_SCTP_AUTH_LABEL);
423
424                SSL_export_keying_material(s, sctpauthkey,
425                                           sizeof(sctpauthkey), labelbuffer,
426                                           sizeof(labelbuffer), NULL, 0, 0);
427
428                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
429                         sizeof(sctpauthkey), sctpauthkey);
430#endif
431#ifndef OPENSSL_NO_TLSEXT
432                if (s->tlsext_ticket_expected)
433                    s->state = SSL3_ST_SW_SESSION_TICKET_A;
434                else
435                    s->state = SSL3_ST_SW_CHANGE_A;
436#else
437                s->state = SSL3_ST_SW_CHANGE_A;
438#endif
439            } else
440                s->state = SSL3_ST_SW_CERT_A;
441            s->init_num = 0;
442            break;
443
444        case SSL3_ST_SW_CERT_A:
445        case SSL3_ST_SW_CERT_B:
446            /* Check if it is anon DH or normal PSK */
447            if (!(s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL)
448                && !(s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
449                dtls1_start_timer(s);
450                ret = ssl3_send_server_certificate(s);
451                if (ret <= 0)
452                    goto end;
453#ifndef OPENSSL_NO_TLSEXT
454                if (s->tlsext_status_expected)
455                    s->state = SSL3_ST_SW_CERT_STATUS_A;
456                else
457                    s->state = SSL3_ST_SW_KEY_EXCH_A;
458            } else {
459                skip = 1;
460                s->state = SSL3_ST_SW_KEY_EXCH_A;
461            }
462#else
463            } else
464                skip = 1;
465
466            s->state = SSL3_ST_SW_KEY_EXCH_A;
467#endif
468            s->init_num = 0;
469            break;
470
471        case SSL3_ST_SW_KEY_EXCH_A:
472        case SSL3_ST_SW_KEY_EXCH_B:
473            alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
474
475            /*
476             * clear this, it may get reset by
477             * send_server_key_exchange
478             */
479            s->s3->tmp.use_rsa_tmp = 0;
480
481            /*
482             * only send if a DH key exchange or RSA but we have a sign only
483             * certificate
484             */
485            if (0
486                /*
487                 * PSK: send ServerKeyExchange if PSK identity hint if
488                 * provided
489                 */
490#ifndef OPENSSL_NO_PSK
491                || ((alg_k & SSL_kPSK) && s->ctx->psk_identity_hint)
492#endif
493                || (alg_k & SSL_kDHE)
494                || (alg_k & SSL_kEECDH)
495                || ((alg_k & SSL_kRSA)
496                    && (s->cert->pkeys[SSL_PKEY_RSA_ENC].privatekey == NULL
497                        || (SSL_C_IS_EXPORT(s->s3->tmp.new_cipher)
498                            && EVP_PKEY_size(s->cert->pkeys
499                                             [SSL_PKEY_RSA_ENC].privatekey) *
500                            8 > SSL_C_EXPORT_PKEYLENGTH(s->s3->tmp.new_cipher)
501                        )
502                    )
503                )
504                ) {
505                dtls1_start_timer(s);
506                ret = ssl3_send_server_key_exchange(s);
507                if (ret <= 0)
508                    goto end;
509            } else
510                skip = 1;
511
512            s->state = SSL3_ST_SW_CERT_REQ_A;
513            s->init_num = 0;
514            break;
515
516        case SSL3_ST_SW_CERT_REQ_A:
517        case SSL3_ST_SW_CERT_REQ_B:
518            if (                /* don't request cert unless asked for it: */
519                   !(s->verify_mode & SSL_VERIFY_PEER) ||
520                   /*
521                    * if SSL_VERIFY_CLIENT_ONCE is set, don't request cert
522                    * during re-negotiation:
523                    */
524                   ((s->session->peer != NULL) &&
525                    (s->verify_mode & SSL_VERIFY_CLIENT_ONCE)) ||
526                   /*
527                    * never request cert in anonymous ciphersuites (see
528                    * section "Certificate request" in SSL 3 drafts and in
529                    * RFC 2246):
530                    */
531                   ((s->s3->tmp.new_cipher->algorithm_auth & SSL_aNULL) &&
532                    /*
533                     * ... except when the application insists on
534                     * verification (against the specs, but s3_clnt.c accepts
535                     * this for SSL 3)
536                     */
537                    !(s->verify_mode & SSL_VERIFY_FAIL_IF_NO_PEER_CERT)) ||
538                   /*
539                    * never request cert in Kerberos ciphersuites
540                    */
541                   (s->s3->tmp.new_cipher->algorithm_auth & SSL_aKRB5)
542                   /*
543                    * With normal PSK Certificates and Certificate Requests
544                    * are omitted
545                    */
546                   || (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)) {
547                /* no cert request */
548                skip = 1;
549                s->s3->tmp.cert_request = 0;
550                s->state = SSL3_ST_SW_SRVR_DONE_A;
551#ifndef OPENSSL_NO_SCTP
552                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
553                    s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
554                    s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
555                }
556#endif
557            } else {
558                s->s3->tmp.cert_request = 1;
559                dtls1_start_timer(s);
560                ret = ssl3_send_certificate_request(s);
561                if (ret <= 0)
562                    goto end;
563#ifndef NETSCAPE_HANG_BUG
564                s->state = SSL3_ST_SW_SRVR_DONE_A;
565# ifndef OPENSSL_NO_SCTP
566                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
567                    s->d1->next_state = SSL3_ST_SW_SRVR_DONE_A;
568                    s->state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
569                }
570# endif
571#else
572                s->state = SSL3_ST_SW_FLUSH;
573                s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
574# ifndef OPENSSL_NO_SCTP
575                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
576                    s->d1->next_state = s->s3->tmp.next_state;
577                    s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
578                }
579# endif
580#endif
581                s->init_num = 0;
582            }
583            break;
584
585        case SSL3_ST_SW_SRVR_DONE_A:
586        case SSL3_ST_SW_SRVR_DONE_B:
587            dtls1_start_timer(s);
588            ret = ssl3_send_server_done(s);
589            if (ret <= 0)
590                goto end;
591            s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
592            s->state = SSL3_ST_SW_FLUSH;
593            s->init_num = 0;
594            break;
595
596        case SSL3_ST_SW_FLUSH:
597            s->rwstate = SSL_WRITING;
598            if (BIO_flush(s->wbio) <= 0) {
599                /*
600                 * If the write error was fatal, stop trying
601                 */
602                if (!BIO_should_retry(s->wbio)) {
603                    s->rwstate = SSL_NOTHING;
604                    s->state = s->s3->tmp.next_state;
605                }
606
607                ret = -1;
608                goto end;
609            }
610            s->rwstate = SSL_NOTHING;
611            s->state = s->s3->tmp.next_state;
612            break;
613
614        case SSL3_ST_SR_CERT_A:
615        case SSL3_ST_SR_CERT_B:
616            if (s->s3->tmp.cert_request) {
617                ret = ssl3_get_client_certificate(s);
618                if (ret <= 0)
619                    goto end;
620            }
621            s->init_num = 0;
622            s->state = SSL3_ST_SR_KEY_EXCH_A;
623            break;
624
625        case SSL3_ST_SR_KEY_EXCH_A:
626        case SSL3_ST_SR_KEY_EXCH_B:
627            ret = ssl3_get_client_key_exchange(s);
628            if (ret <= 0)
629                goto end;
630#ifndef OPENSSL_NO_SCTP
631            /*
632             * Add new shared key for SCTP-Auth, will be ignored if no SCTP
633             * used.
634             */
635            snprintf((char *)labelbuffer, sizeof(DTLS1_SCTP_AUTH_LABEL),
636                     DTLS1_SCTP_AUTH_LABEL);
637
638            SSL_export_keying_material(s, sctpauthkey,
639                                       sizeof(sctpauthkey), labelbuffer,
640                                       sizeof(labelbuffer), NULL, 0, 0);
641
642            BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_ADD_AUTH_KEY,
643                     sizeof(sctpauthkey), sctpauthkey);
644#endif
645
646            s->state = SSL3_ST_SR_CERT_VRFY_A;
647            s->init_num = 0;
648
649            if (ret == 2) {
650                /*
651                 * For the ECDH ciphersuites when the client sends its ECDH
652                 * pub key in a certificate, the CertificateVerify message is
653                 * not sent.
654                 */
655                s->state = SSL3_ST_SR_FINISHED_A;
656                s->init_num = 0;
657            } else if (SSL_USE_SIGALGS(s)) {
658                s->state = SSL3_ST_SR_CERT_VRFY_A;
659                s->init_num = 0;
660                if (!s->session->peer)
661                    break;
662                /*
663                 * For sigalgs freeze the handshake buffer at this point and
664                 * digest cached records.
665                 */
666                if (!s->s3->handshake_buffer) {
667                    SSLerr(SSL_F_DTLS1_ACCEPT, ERR_R_INTERNAL_ERROR);
668                    s->state = SSL_ST_ERR;
669                    return -1;
670                }
671                s->s3->flags |= TLS1_FLAGS_KEEP_HANDSHAKE;
672                if (!ssl3_digest_cached_records(s)) {
673                    s->state = SSL_ST_ERR;
674                    return -1;
675                }
676            } else {
677                s->state = SSL3_ST_SR_CERT_VRFY_A;
678                s->init_num = 0;
679
680                /*
681                 * We need to get hashes here so if there is a client cert,
682                 * it can be verified
683                 */
684                s->method->ssl3_enc->cert_verify_mac(s,
685                                                     NID_md5,
686                                                     &(s->s3->
687                                                       tmp.cert_verify_md
688                                                       [0]));
689                s->method->ssl3_enc->cert_verify_mac(s, NID_sha1,
690                                                     &(s->s3->
691                                                       tmp.cert_verify_md
692                                                       [MD5_DIGEST_LENGTH]));
693            }
694            break;
695
696        case SSL3_ST_SR_CERT_VRFY_A:
697        case SSL3_ST_SR_CERT_VRFY_B:
698            ret = ssl3_get_cert_verify(s);
699            if (ret <= 0)
700                goto end;
701#ifndef OPENSSL_NO_SCTP
702            if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
703                state == SSL_ST_RENEGOTIATE)
704                s->state = DTLS1_SCTP_ST_SR_READ_SOCK;
705            else
706#endif
707                s->state = SSL3_ST_SR_FINISHED_A;
708            s->init_num = 0;
709            break;
710
711        case SSL3_ST_SR_FINISHED_A:
712        case SSL3_ST_SR_FINISHED_B:
713            /*
714             * Enable CCS. Receiving a CCS clears the flag, so make
715             * sure not to re-enable it to ban duplicates. This *should* be the
716             * first time we have received one - but we check anyway to be
717             * cautious.
718             * s->s3->change_cipher_spec is set when a CCS is
719             * processed in d1_pkt.c, and remains set until
720             * the client's Finished message is read.
721             */
722            if (!s->s3->change_cipher_spec)
723                s->d1->change_cipher_spec_ok = 1;
724            ret = ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A,
725                                    SSL3_ST_SR_FINISHED_B);
726            if (ret <= 0)
727                goto end;
728            dtls1_stop_timer(s);
729            if (s->hit)
730                s->state = SSL_ST_OK;
731#ifndef OPENSSL_NO_TLSEXT
732            else if (s->tlsext_ticket_expected)
733                s->state = SSL3_ST_SW_SESSION_TICKET_A;
734#endif
735            else
736                s->state = SSL3_ST_SW_CHANGE_A;
737            s->init_num = 0;
738            break;
739
740#ifndef OPENSSL_NO_TLSEXT
741        case SSL3_ST_SW_SESSION_TICKET_A:
742        case SSL3_ST_SW_SESSION_TICKET_B:
743            ret = ssl3_send_newsession_ticket(s);
744            if (ret <= 0)
745                goto end;
746            s->state = SSL3_ST_SW_CHANGE_A;
747            s->init_num = 0;
748            break;
749
750        case SSL3_ST_SW_CERT_STATUS_A:
751        case SSL3_ST_SW_CERT_STATUS_B:
752            ret = ssl3_send_cert_status(s);
753            if (ret <= 0)
754                goto end;
755            s->state = SSL3_ST_SW_KEY_EXCH_A;
756            s->init_num = 0;
757            break;
758
759#endif
760
761        case SSL3_ST_SW_CHANGE_A:
762        case SSL3_ST_SW_CHANGE_B:
763
764            s->session->cipher = s->s3->tmp.new_cipher;
765            if (!s->method->ssl3_enc->setup_key_block(s)) {
766                ret = -1;
767                s->state = SSL_ST_ERR;
768                goto end;
769            }
770
771            ret = dtls1_send_change_cipher_spec(s,
772                                                SSL3_ST_SW_CHANGE_A,
773                                                SSL3_ST_SW_CHANGE_B);
774
775            if (ret <= 0)
776                goto end;
777
778#ifndef OPENSSL_NO_SCTP
779            if (!s->hit) {
780                /*
781                 * Change to new shared key of SCTP-Auth, will be ignored if
782                 * no SCTP used.
783                 */
784                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
785                         0, NULL);
786            }
787#endif
788
789            s->state = SSL3_ST_SW_FINISHED_A;
790            s->init_num = 0;
791
792            if (!s->method->ssl3_enc->change_cipher_state(s,
793                                                          SSL3_CHANGE_CIPHER_SERVER_WRITE))
794            {
795                ret = -1;
796                s->state = SSL_ST_ERR;
797                goto end;
798            }
799
800            dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
801            break;
802
803        case SSL3_ST_SW_FINISHED_A:
804        case SSL3_ST_SW_FINISHED_B:
805            ret = ssl3_send_finished(s,
806                                     SSL3_ST_SW_FINISHED_A,
807                                     SSL3_ST_SW_FINISHED_B,
808                                     s->method->
809                                     ssl3_enc->server_finished_label,
810                                     s->method->
811                                     ssl3_enc->server_finished_label_len);
812            if (ret <= 0)
813                goto end;
814            s->state = SSL3_ST_SW_FLUSH;
815            if (s->hit) {
816                s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
817
818#ifndef OPENSSL_NO_SCTP
819                /*
820                 * Change to new shared key of SCTP-Auth, will be ignored if
821                 * no SCTP used.
822                 */
823                BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_NEXT_AUTH_KEY,
824                         0, NULL);
825#endif
826            } else {
827                s->s3->tmp.next_state = SSL_ST_OK;
828#ifndef OPENSSL_NO_SCTP
829                if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
830                    s->d1->next_state = s->s3->tmp.next_state;
831                    s->s3->tmp.next_state = DTLS1_SCTP_ST_SW_WRITE_SOCK;
832                }
833#endif
834            }
835            s->init_num = 0;
836            break;
837
838        case SSL_ST_OK:
839            /* clean a few things up */
840            ssl3_cleanup_key_block(s);
841
842#if 0
843            BUF_MEM_free(s->init_buf);
844            s->init_buf = NULL;
845#endif
846
847            /* remove buffering on output */
848            ssl_free_wbio_buffer(s);
849
850            s->init_num = 0;
851
852            if (s->renegotiate == 2) { /* skipped if we just sent a
853                                        * HelloRequest */
854                s->renegotiate = 0;
855                s->new_session = 0;
856
857                ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
858
859                s->ctx->stats.sess_accept_good++;
860                /* s->server=1; */
861                s->handshake_func = dtls1_accept;
862
863                if (cb != NULL)
864                    cb(s, SSL_CB_HANDSHAKE_DONE, 1);
865            }
866
867            ret = 1;
868
869            /* done handshaking, next message is client hello */
870            s->d1->handshake_read_seq = 0;
871            /* next message is server hello */
872            s->d1->handshake_write_seq = 0;
873            s->d1->next_handshake_write_seq = 0;
874            goto end;
875            /* break; */
876
877        case SSL_ST_ERR:
878        default:
879            SSLerr(SSL_F_DTLS1_ACCEPT, SSL_R_UNKNOWN_STATE);
880            ret = -1;
881            goto end;
882            /* break; */
883        }
884
885        if (!s->s3->tmp.reuse_message && !skip) {
886            if (s->debug) {
887                if ((ret = BIO_flush(s->wbio)) <= 0)
888                    goto end;
889            }
890
891            if ((cb != NULL) && (s->state != state)) {
892                new_state = s->state;
893                s->state = state;
894                cb(s, SSL_CB_ACCEPT_LOOP, 1);
895                s->state = new_state;
896            }
897        }
898        skip = 0;
899    }
900 end:
901    /* BIO_flush(s->wbio); */
902
903    s->in_handshake--;
904#ifndef OPENSSL_NO_SCTP
905    /*
906     * Notify SCTP BIO socket to leave handshake mode and prevent stream
907     * identifier other than 0. Will be ignored if no SCTP is used.
908     */
909    BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SET_IN_HANDSHAKE,
910             s->in_handshake, NULL);
911#endif
912
913    if (cb != NULL)
914        cb(s, SSL_CB_ACCEPT_EXIT, ret);
915    return (ret);
916}
917
918int dtls1_send_hello_verify_request(SSL *s)
919{
920    unsigned int msg_len;
921    unsigned char *msg, *buf, *p;
922
923    if (s->state == DTLS1_ST_SW_HELLO_VERIFY_REQUEST_A) {
924        buf = (unsigned char *)s->init_buf->data;
925
926        msg = p = &(buf[DTLS1_HM_HEADER_LENGTH]);
927        /* Always use DTLS 1.0 version: see RFC 6347 */
928        *(p++) = DTLS1_VERSION >> 8;
929        *(p++) = DTLS1_VERSION & 0xFF;
930
931        if (s->ctx->app_gen_cookie_cb == NULL ||
932            s->ctx->app_gen_cookie_cb(s, s->d1->cookie,
933                                      &(s->d1->cookie_len)) == 0) {
934            SSLerr(SSL_F_DTLS1_SEND_HELLO_VERIFY_REQUEST,
935                   ERR_R_INTERNAL_ERROR);
936            s->state = SSL_ST_ERR;
937            return 0;
938        }
939
940        *(p++) = (unsigned char)s->d1->cookie_len;
941        memcpy(p, s->d1->cookie, s->d1->cookie_len);
942        p += s->d1->cookie_len;
943        msg_len = p - msg;
944
945        dtls1_set_message_header(s, buf,
946                                 DTLS1_MT_HELLO_VERIFY_REQUEST, msg_len, 0,
947                                 msg_len);
948
949        s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B;
950        /* number of bytes to write */
951        s->init_num = p - buf;
952        s->init_off = 0;
953    }
954
955    /* s->state = DTLS1_ST_SW_HELLO_VERIFY_REQUEST_B */
956    return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
957}
958