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- /*
- * DTLS implementation written by Nagendra Modadugu
- * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
- */
- /* ====================================================================
- * Copyright (c) 1999-2007 The OpenSSL Project. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in
- * the documentation and/or other materials provided with the
- * distribution.
- *
- * 3. All advertising materials mentioning features or use of this
- * software must display the following acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
- *
- * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
- * endorse or promote products derived from this software without
- * prior written permission. For written permission, please contact
- * openssl-core@OpenSSL.org.
- *
- * 5. Products derived from this software may not be called "OpenSSL"
- * nor may "OpenSSL" appear in their names without prior written
- * permission of the OpenSSL Project.
- *
- * 6. Redistributions of any form whatsoever must retain the following
- * acknowledgment:
- * "This product includes software developed by the OpenSSL Project
- * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
- *
- * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
- * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
- * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
- * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
- * OF THE POSSIBILITY OF SUCH DAMAGE.
- * ====================================================================
- *
- * This product includes cryptographic software written by Eric Young
- * (eay@cryptsoft.com). This product includes software written by Tim
- * Hudson (tjh@cryptsoft.com).
- *
- */
- /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
- *
- * This package is an SSL implementation written
- * by Eric Young (eay@cryptsoft.com).
- * The implementation was written so as to conform with Netscapes SSL.
- *
- * This library is free for commercial and non-commercial use as long as
- * the following conditions are aheared to. The following conditions
- * apply to all code found in this distribution, be it the RC4, RSA,
- * lhash, DES, etc., code; not just the SSL code. The SSL documentation
- * included with this distribution is covered by the same copyright terms
- * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- *
- * Copyright remains Eric Young's, and as such any Copyright notices in
- * the code are not to be removed.
- * If this package is used in a product, Eric Young should be given attribution
- * as the author of the parts of the library used.
- * This can be in the form of a textual message at program startup or
- * in documentation (online or textual) provided with the package.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * "This product includes cryptographic software written by
- * Eric Young (eay@cryptsoft.com)"
- * The word 'cryptographic' can be left out if the rouines from the library
- * being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from
- * the apps directory (application code) you must include an acknowledgement:
- * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- *
- * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * The licence and distribution terms for any publically available version or
- * derivative of this code cannot be changed. i.e. this code cannot simply be
- * copied and put under another distribution licence
- * [including the GNU Public Licence.]
- */
-
- #include <assert.h>
- #include <stdio.h>
-
- #include <openssl/bn.h>
- #include <openssl/buf.h>
- #include <openssl/dh.h>
- #include <openssl/err.h>
- #include <openssl/evp.h>
- #include <openssl/md5.h>
- #include <openssl/obj.h>
- #include <openssl/rand.h>
- #include <openssl/x509.h>
-
- #include "internal.h"
-
-
- int dtls1_accept(SSL *s) {
- BUF_MEM *buf = NULL;
- void (*cb)(const SSL *ssl, int type, int val) = NULL;
- uint32_t alg_a;
- int ret = -1;
- int new_state, state, skip = 0;
-
- assert(s->handshake_func == dtls1_accept);
- assert(s->server);
- assert(SSL_IS_DTLS(s));
-
- ERR_clear_error();
- ERR_clear_system_error();
-
- if (s->info_callback != NULL) {
- cb = s->info_callback;
- } else if (s->ctx->info_callback != NULL) {
- cb = s->ctx->info_callback;
- }
-
- s->in_handshake++;
-
- if (s->cert == NULL) {
- OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CERTIFICATE_SET);
- return -1;
- }
-
- for (;;) {
- state = s->state;
-
- switch (s->state) {
- case SSL_ST_ACCEPT:
- if (cb != NULL) {
- cb(s, SSL_CB_HANDSHAKE_START, 1);
- }
-
- if (s->init_buf == NULL) {
- buf = BUF_MEM_new();
- if (buf == NULL || !BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
- ret = -1;
- goto end;
- }
- s->init_buf = buf;
- buf = NULL;
- }
-
- s->init_num = 0;
-
- if (!ssl_init_wbio_buffer(s, 1)) {
- ret = -1;
- goto end;
- }
-
- if (!ssl3_init_handshake_buffer(s)) {
- OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
- ret = -1;
- goto end;
- }
-
- s->state = SSL3_ST_SR_CLNT_HELLO_A;
- break;
-
- case SSL3_ST_SR_CLNT_HELLO_A:
- case SSL3_ST_SR_CLNT_HELLO_B:
- case SSL3_ST_SR_CLNT_HELLO_C:
- case SSL3_ST_SR_CLNT_HELLO_D:
- s->shutdown = 0;
- ret = ssl3_get_client_hello(s);
- if (ret <= 0) {
- goto end;
- }
- dtls1_stop_timer(s);
- s->state = SSL3_ST_SW_SRVR_HELLO_A;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_SRVR_HELLO_A:
- case SSL3_ST_SW_SRVR_HELLO_B:
- dtls1_start_timer(s);
- ret = ssl3_send_server_hello(s);
- if (ret <= 0) {
- goto end;
- }
-
- if (s->hit) {
- if (s->tlsext_ticket_expected) {
- s->state = SSL3_ST_SW_SESSION_TICKET_A;
- } else {
- s->state = SSL3_ST_SW_CHANGE_A;
- }
- } else {
- s->state = SSL3_ST_SW_CERT_A;
- }
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_CERT_A:
- case SSL3_ST_SW_CERT_B:
- if (ssl_cipher_has_server_public_key(s->s3->tmp.new_cipher)) {
- dtls1_start_timer(s);
- ret = ssl3_send_server_certificate(s);
- if (ret <= 0) {
- goto end;
- }
- if (s->s3->tmp.certificate_status_expected) {
- s->state = SSL3_ST_SW_CERT_STATUS_A;
- } else {
- s->state = SSL3_ST_SW_KEY_EXCH_A;
- }
- } else {
- skip = 1;
- s->state = SSL3_ST_SW_KEY_EXCH_A;
- }
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_KEY_EXCH_A:
- case SSL3_ST_SW_KEY_EXCH_B:
- case SSL3_ST_SW_KEY_EXCH_C:
- case SSL3_ST_SW_KEY_EXCH_D:
- alg_a = s->s3->tmp.new_cipher->algorithm_auth;
-
- /* Send a ServerKeyExchange message if:
- * - The key exchange is ephemeral or anonymous
- * Diffie-Hellman.
- * - There is a PSK identity hint.
- *
- * TODO(davidben): This logic is currently duplicated
- * in s3_srvr.c. Fix this. In the meantime, keep them
- * in sync. */
- if (ssl_cipher_requires_server_key_exchange(s->s3->tmp.new_cipher) ||
- ((alg_a & SSL_aPSK) && s->psk_identity_hint)) {
- dtls1_start_timer(s);
- ret = ssl3_send_server_key_exchange(s);
- if (ret <= 0) {
- goto end;
- }
- } else {
- skip = 1;
- }
-
- s->state = SSL3_ST_SW_CERT_REQ_A;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_CERT_REQ_A:
- case SSL3_ST_SW_CERT_REQ_B:
- if (s->s3->tmp.cert_request) {
- dtls1_start_timer(s);
- ret = ssl3_send_certificate_request(s);
- if (ret <= 0) {
- goto end;
- }
- } else {
- skip = 1;
- }
- s->state = SSL3_ST_SW_SRVR_DONE_A;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_SRVR_DONE_A:
- case SSL3_ST_SW_SRVR_DONE_B:
- dtls1_start_timer(s);
- ret = ssl3_send_server_done(s);
- if (ret <= 0) {
- goto end;
- }
- s->s3->tmp.next_state = SSL3_ST_SR_CERT_A;
- s->state = SSL3_ST_SW_FLUSH;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_FLUSH:
- s->rwstate = SSL_WRITING;
- if (BIO_flush(s->wbio) <= 0) {
- ret = -1;
- goto end;
- }
- s->rwstate = SSL_NOTHING;
- s->state = s->s3->tmp.next_state;
- break;
-
- case SSL3_ST_SR_CERT_A:
- case SSL3_ST_SR_CERT_B:
- if (s->s3->tmp.cert_request) {
- ret = ssl3_get_client_certificate(s);
- if (ret <= 0) {
- goto end;
- }
- }
- s->init_num = 0;
- s->state = SSL3_ST_SR_KEY_EXCH_A;
- break;
-
- case SSL3_ST_SR_KEY_EXCH_A:
- case SSL3_ST_SR_KEY_EXCH_B:
- ret = ssl3_get_client_key_exchange(s);
- if (ret <= 0) {
- goto end;
- }
- s->state = SSL3_ST_SR_CERT_VRFY_A;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SR_CERT_VRFY_A:
- case SSL3_ST_SR_CERT_VRFY_B:
- ret = ssl3_get_cert_verify(s);
- if (ret <= 0) {
- goto end;
- }
- s->state = SSL3_ST_SR_FINISHED_A;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SR_FINISHED_A:
- case SSL3_ST_SR_FINISHED_B:
- s->d1->change_cipher_spec_ok = 1;
- ret =
- ssl3_get_finished(s, SSL3_ST_SR_FINISHED_A, SSL3_ST_SR_FINISHED_B);
- if (ret <= 0) {
- goto end;
- }
- dtls1_stop_timer(s);
- if (s->hit) {
- s->state = SSL_ST_OK;
- } else if (s->tlsext_ticket_expected) {
- s->state = SSL3_ST_SW_SESSION_TICKET_A;
- } else {
- s->state = SSL3_ST_SW_CHANGE_A;
- }
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_SESSION_TICKET_A:
- case SSL3_ST_SW_SESSION_TICKET_B:
- ret = ssl3_send_new_session_ticket(s);
- if (ret <= 0) {
- goto end;
- }
- s->state = SSL3_ST_SW_CHANGE_A;
- s->init_num = 0;
- break;
-
- case SSL3_ST_SW_CHANGE_A:
- case SSL3_ST_SW_CHANGE_B:
- s->session->cipher = s->s3->tmp.new_cipher;
- if (!s->enc_method->setup_key_block(s)) {
- ret = -1;
- goto end;
- }
-
- ret = dtls1_send_change_cipher_spec(s, SSL3_ST_SW_CHANGE_A,
- SSL3_ST_SW_CHANGE_B);
-
- if (ret <= 0) {
- goto end;
- }
-
- s->state = SSL3_ST_SW_FINISHED_A;
- s->init_num = 0;
-
- if (!s->enc_method->change_cipher_state(
- s, SSL3_CHANGE_CIPHER_SERVER_WRITE)) {
- ret = -1;
- goto end;
- }
-
- dtls1_reset_seq_numbers(s, SSL3_CC_WRITE);
- break;
-
- case SSL3_ST_SW_FINISHED_A:
- case SSL3_ST_SW_FINISHED_B:
- ret =
- ssl3_send_finished(s, SSL3_ST_SW_FINISHED_A, SSL3_ST_SW_FINISHED_B,
- s->enc_method->server_finished_label,
- s->enc_method->server_finished_label_len);
- if (ret <= 0) {
- goto end;
- }
- s->state = SSL3_ST_SW_FLUSH;
- if (s->hit) {
- s->s3->tmp.next_state = SSL3_ST_SR_FINISHED_A;
- } else {
- s->s3->tmp.next_state = SSL_ST_OK;
- }
- s->init_num = 0;
- break;
-
- case SSL_ST_OK:
- ssl3_cleanup_key_block(s);
-
- /* remove buffering on output */
- ssl_free_wbio_buffer(s);
-
- s->init_num = 0;
- s->s3->initial_handshake_complete = 1;
-
- ssl_update_cache(s, SSL_SESS_CACHE_SERVER);
-
- if (cb != NULL) {
- cb(s, SSL_CB_HANDSHAKE_DONE, 1);
- }
-
- ret = 1;
-
- /* done handshaking, next message is client hello */
- s->d1->handshake_read_seq = 0;
- /* next message is server hello */
- s->d1->handshake_write_seq = 0;
- s->d1->next_handshake_write_seq = 0;
- goto end;
-
- default:
- OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
- ret = -1;
- goto end;
- }
-
- if (!s->s3->tmp.reuse_message && !skip) {
- if (cb != NULL && s->state != state) {
- new_state = s->state;
- s->state = state;
- cb(s, SSL_CB_ACCEPT_LOOP, 1);
- s->state = new_state;
- }
- }
- skip = 0;
- }
-
- end:
- s->in_handshake--;
- BUF_MEM_free(buf);
- if (cb != NULL) {
- cb(s, SSL_CB_ACCEPT_EXIT, ret);
- }
- return ret;
- }
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