nexmon – Rev 1
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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 <openssl/ssl.h>
#include <assert.h>
#include <string.h>
#include <openssl/bn.h>
#include <openssl/buf.h>
#include <openssl/dh.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/md5.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include "internal.h"
static int dtls1_get_hello_verify(SSL *ssl);
int dtls1_connect(SSL *ssl) {
BUF_MEM *buf = NULL;
void (*cb)(const SSL *ssl, int type, int value) = NULL;
int ret = -1;
int new_state, state, skip = 0;
assert(ssl->handshake_func == dtls1_connect);
assert(!ssl->server);
assert(SSL_IS_DTLS(ssl));
ERR_clear_system_error();
if (ssl->info_callback != NULL) {
cb = ssl->info_callback;
} else if (ssl->ctx->info_callback != NULL) {
cb = ssl->ctx->info_callback;
}
for (;;) {
state = ssl->state;
switch (ssl->state) {
case SSL_ST_CONNECT:
if (cb != NULL) {
cb(ssl, SSL_CB_HANDSHAKE_START, 1);
}
if (ssl->init_buf == NULL) {
buf = BUF_MEM_new();
if (buf == NULL ||
!BUF_MEM_grow(buf, SSL3_RT_MAX_PLAIN_LENGTH)) {
ret = -1;
goto end;
}
ssl->init_buf = buf;
buf = NULL;
}
if (!ssl_init_wbio_buffer(ssl, 0)) {
ret = -1;
goto end;
}
/* don't push the buffering BIO quite yet */
ssl->state = SSL3_ST_CW_CLNT_HELLO_A;
ssl->init_num = 0;
ssl->d1->send_cookie = 0;
ssl->hit = 0;
break;
case SSL3_ST_CW_CLNT_HELLO_A:
case SSL3_ST_CW_CLNT_HELLO_B:
ssl->shutdown = 0;
dtls1_start_timer(ssl);
ret = ssl3_send_client_hello(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->d1->send_cookie) {
ssl->state = SSL3_ST_CW_FLUSH;
ssl->s3->tmp.next_state = SSL3_ST_CR_SRVR_HELLO_A;
} else {
ssl->state = DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A;
}
ssl->init_num = 0;
/* turn on buffering for the next lot of output */
if (ssl->bbio != ssl->wbio) {
ssl->wbio = BIO_push(ssl->bbio, ssl->wbio);
}
break;
case DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A:
case DTLS1_ST_CR_HELLO_VERIFY_REQUEST_B:
ret = dtls1_get_hello_verify(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->d1->send_cookie) {
/* start again, with a cookie */
dtls1_stop_timer(ssl);
ssl->state = SSL3_ST_CW_CLNT_HELLO_A;
} else {
ssl->state = SSL3_ST_CR_SRVR_HELLO_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_CR_SRVR_HELLO_A:
case SSL3_ST_CR_SRVR_HELLO_B:
ret = ssl3_get_server_hello(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->hit) {
ssl->state = SSL3_ST_CR_CHANGE;
if (ssl->tlsext_ticket_expected) {
/* receive renewed session ticket */
ssl->state = SSL3_ST_CR_SESSION_TICKET_A;
}
} else {
ssl->state = SSL3_ST_CR_CERT_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_CR_CERT_A:
case SSL3_ST_CR_CERT_B:
if (ssl_cipher_has_server_public_key(ssl->s3->tmp.new_cipher)) {
ret = ssl3_get_server_certificate(ssl);
if (ret <= 0) {
goto end;
}
if (ssl->s3->tmp.certificate_status_expected) {
ssl->state = SSL3_ST_CR_CERT_STATUS_A;
} else {
ssl->state = SSL3_ST_VERIFY_SERVER_CERT;
}
} else {
skip = 1;
ssl->state = SSL3_ST_CR_KEY_EXCH_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_VERIFY_SERVER_CERT:
ret = ssl3_verify_server_cert(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CR_KEY_EXCH_A;
ssl->init_num = 0;
break;
case SSL3_ST_CR_KEY_EXCH_A:
case SSL3_ST_CR_KEY_EXCH_B:
ret = ssl3_get_server_key_exchange(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CR_CERT_REQ_A;
ssl->init_num = 0;
break;
case SSL3_ST_CR_CERT_REQ_A:
case SSL3_ST_CR_CERT_REQ_B:
ret = ssl3_get_certificate_request(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CR_SRVR_DONE_A;
ssl->init_num = 0;
break;
case SSL3_ST_CR_SRVR_DONE_A:
case SSL3_ST_CR_SRVR_DONE_B:
ret = ssl3_get_server_done(ssl);
if (ret <= 0) {
goto end;
}
dtls1_stop_timer(ssl);
if (ssl->s3->tmp.cert_req) {
ssl->s3->tmp.next_state = SSL3_ST_CW_CERT_A;
} else {
ssl->s3->tmp.next_state = SSL3_ST_CW_KEY_EXCH_A;
}
ssl->init_num = 0;
ssl->state = ssl->s3->tmp.next_state;
break;
case SSL3_ST_CW_CERT_A:
case SSL3_ST_CW_CERT_B:
case SSL3_ST_CW_CERT_C:
case SSL3_ST_CW_CERT_D:
dtls1_start_timer(ssl);
ret = ssl3_send_client_certificate(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CW_KEY_EXCH_A;
ssl->init_num = 0;
break;
case SSL3_ST_CW_KEY_EXCH_A:
case SSL3_ST_CW_KEY_EXCH_B:
dtls1_start_timer(ssl);
ret = ssl3_send_client_key_exchange(ssl);
if (ret <= 0) {
goto end;
}
/* For TLS, cert_req is set to 2, so a cert chain
* of nothing is sent, but no verify packet is sent */
if (ssl->s3->tmp.cert_req == 1) {
ssl->state = SSL3_ST_CW_CERT_VRFY_A;
} else {
ssl->state = SSL3_ST_CW_CHANGE_A;
}
ssl->init_num = 0;
break;
case SSL3_ST_CW_CERT_VRFY_A:
case SSL3_ST_CW_CERT_VRFY_B:
case SSL3_ST_CW_CERT_VRFY_C:
dtls1_start_timer(ssl);
ret = ssl3_send_cert_verify(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CW_CHANGE_A;
ssl->init_num = 0;
break;
case SSL3_ST_CW_CHANGE_A:
case SSL3_ST_CW_CHANGE_B:
if (!ssl->hit) {
dtls1_start_timer(ssl);
}
ret = dtls1_send_change_cipher_spec(ssl, SSL3_ST_CW_CHANGE_A,
SSL3_ST_CW_CHANGE_B);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CW_FINISHED_A;
ssl->init_num = 0;
if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_CLIENT_WRITE)) {
ret = -1;
goto end;
}
break;
case SSL3_ST_CW_FINISHED_A:
case SSL3_ST_CW_FINISHED_B:
if (!ssl->hit) {
dtls1_start_timer(ssl);
}
ret = ssl3_send_finished(ssl, SSL3_ST_CW_FINISHED_A,
SSL3_ST_CW_FINISHED_B);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CW_FLUSH;
if (ssl->hit) {
ssl->s3->tmp.next_state = SSL_ST_OK;
} else {
/* Allow NewSessionTicket if ticket expected */
if (ssl->tlsext_ticket_expected) {
ssl->s3->tmp.next_state = SSL3_ST_CR_SESSION_TICKET_A;
} else {
ssl->s3->tmp.next_state = SSL3_ST_CR_CHANGE;
}
}
ssl->init_num = 0;
break;
case SSL3_ST_CR_SESSION_TICKET_A:
case SSL3_ST_CR_SESSION_TICKET_B:
ret = ssl3_get_new_session_ticket(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_CR_CHANGE;
ssl->init_num = 0;
break;
case SSL3_ST_CR_CERT_STATUS_A:
case SSL3_ST_CR_CERT_STATUS_B:
ret = ssl3_get_cert_status(ssl);
if (ret <= 0) {
goto end;
}
ssl->state = SSL3_ST_VERIFY_SERVER_CERT;
ssl->init_num = 0;
break;
case SSL3_ST_CR_CHANGE:
ret = ssl->method->ssl_read_change_cipher_spec(ssl);
if (ret <= 0) {
goto end;
}
if (!tls1_change_cipher_state(ssl, SSL3_CHANGE_CIPHER_CLIENT_READ)) {
ret = -1;
goto end;
}
ssl->state = SSL3_ST_CR_FINISHED_A;
break;
case SSL3_ST_CR_FINISHED_A:
case SSL3_ST_CR_FINISHED_B:
ret =
ssl3_get_finished(ssl, SSL3_ST_CR_FINISHED_A, SSL3_ST_CR_FINISHED_B);
if (ret <= 0) {
goto end;
}
dtls1_stop_timer(ssl);
if (ssl->hit) {
ssl->state = SSL3_ST_CW_CHANGE_A;
} else {
ssl->state = SSL_ST_OK;
}
ssl->init_num = 0;
break;
case SSL3_ST_CW_FLUSH:
if (BIO_flush(ssl->wbio) <= 0) {
ssl->rwstate = SSL_WRITING;
ret = -1;
goto end;
}
ssl->state = ssl->s3->tmp.next_state;
break;
case SSL_ST_OK:
/* clean a few things up */
ssl3_cleanup_key_block(ssl);
/* Remove write buffering now. */
ssl_free_wbio_buffer(ssl);
ssl->init_num = 0;
ssl->s3->initial_handshake_complete = 1;
ssl_update_cache(ssl, SSL_SESS_CACHE_CLIENT);
ret = 1;
if (cb != NULL) {
cb(ssl, SSL_CB_HANDSHAKE_DONE, 1);
}
/* done with handshaking */
ssl->d1->handshake_read_seq = 0;
ssl->d1->next_handshake_write_seq = 0;
goto end;
default:
OPENSSL_PUT_ERROR(SSL, SSL_R_UNKNOWN_STATE);
ret = -1;
goto end;
}
/* did we do anything? */
if (!ssl->s3->tmp.reuse_message && !skip) {
if ((cb != NULL) && (ssl->state != state)) {
new_state = ssl->state;
ssl->state = state;
cb(ssl, SSL_CB_CONNECT_LOOP, 1);
ssl->state = new_state;
}
}
skip = 0;
}
end:
BUF_MEM_free(buf);
if (cb != NULL) {
cb(ssl, SSL_CB_CONNECT_EXIT, ret);
}
return ret;
}
static int dtls1_get_hello_verify(SSL *ssl) {
long n;
int al, ok = 0;
CBS hello_verify_request, cookie;
uint16_t server_version;
n = ssl->method->ssl_get_message(
ssl, DTLS1_ST_CR_HELLO_VERIFY_REQUEST_A,
DTLS1_ST_CR_HELLO_VERIFY_REQUEST_B, -1,
/* Use the same maximum size as ssl3_get_server_hello. */
20000, ssl_hash_message, &ok);
if (!ok) {
return n;
}
if (ssl->s3->tmp.message_type != DTLS1_MT_HELLO_VERIFY_REQUEST) {
ssl->d1->send_cookie = 0;
ssl->s3->tmp.reuse_message = 1;
return 1;
}
CBS_init(&hello_verify_request, ssl->init_msg, n);
if (!CBS_get_u16(&hello_verify_request, &server_version) ||
!CBS_get_u8_length_prefixed(&hello_verify_request, &cookie) ||
CBS_len(&hello_verify_request) != 0) {
al = SSL_AD_DECODE_ERROR;
OPENSSL_PUT_ERROR(SSL, SSL_R_DECODE_ERROR);
goto f_err;
}
if (CBS_len(&cookie) > sizeof(ssl->d1->cookie)) {
al = SSL_AD_ILLEGAL_PARAMETER;
goto f_err;
}
memcpy(ssl->d1->cookie, CBS_data(&cookie), CBS_len(&cookie));
ssl->d1->cookie_len = CBS_len(&cookie);
ssl->d1->send_cookie = 1;
return 1;
f_err:
ssl3_send_alert(ssl, SSL3_AL_FATAL, al);
return -1;
}