/*
* 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, dtls1_accept, 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_finished_mac(s)) {
OPENSSL_PUT_ERROR(SSL, dtls1_accept, 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:
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, dtls1_accept, 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;
}