mbedtls/programs/ssl/dtls_client.c
Simon Butcher b5b6af2663 Puts platform time abstraction into its own header
Separates platform time abstraction into it's own header from the
general platform abstraction as both depend on different build options.
(MBEDTLS_PLATFORM_C vs MBEDTLS_HAVE_TIME)
2016-07-13 14:46:18 +01:00

350 lines
10 KiB
C

/*
* Simple DTLS client demonstration program
*
* Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_PLATFORM_C)
#include "mbedtls/platform.h"
#else
#include <stdio.h>
#define mbedtls_printf printf
#define mbedtls_fprintf fprintf
#endif
#if !defined(MBEDTLS_SSL_CLI_C) || !defined(MBEDTLS_SSL_PROTO_DTLS) || \
!defined(MBEDTLS_NET_C) || !defined(MBEDTLS_TIMING_C) || \
!defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
!defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_RSA_C) || \
!defined(MBEDTLS_CERTS_C)
int main( void )
{
mbedtls_printf( "MBEDTLS_SSL_CLI_C and/or MBEDTLS_SSL_PROTO_DTLS and/or "
"MBEDTLS_NET_C and/or MBEDTLS_TIMING_C and/or "
"MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
"MBEDTLS_X509_CRT_PARSE_C and/or MBEDTLS_RSA_C and/or "
"MBEDTLS_CERTS_C and/or MBEDTLS_PEM_PARSE_C not defined.\n" );
return( 0 );
}
#else
#include <string.h>
#include "mbedtls/net.h"
#include "mbedtls/debug.h"
#include "mbedtls/ssl.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/error.h"
#include "mbedtls/certs.h"
#include "mbedtls/timing.h"
#define SERVER_PORT "4433"
#define SERVER_NAME "localhost"
#define SERVER_ADDR "127.0.0.1" /* forces IPv4 */
#define MESSAGE "Echo this"
#define READ_TIMEOUT_MS 1000
#define MAX_RETRY 5
#define DEBUG_LEVEL 0
static void my_debug( void *ctx, int level,
const char *file, int line,
const char *str )
{
((void) level);
mbedtls_fprintf( (FILE *) ctx, "%s:%04d: %s", file, line, str );
fflush( (FILE *) ctx );
}
int main( int argc, char *argv[] )
{
int ret, len;
mbedtls_net_context server_fd;
uint32_t flags;
unsigned char buf[1024];
const char *pers = "dtls_client";
int retry_left = MAX_RETRY;
mbedtls_entropy_context entropy;
mbedtls_ctr_drbg_context ctr_drbg;
mbedtls_ssl_context ssl;
mbedtls_ssl_config conf;
mbedtls_x509_crt cacert;
mbedtls_timing_delay_context timer;
((void) argc);
((void) argv);
#if defined(MBEDTLS_DEBUG_C)
mbedtls_debug_set_threshold( DEBUG_LEVEL );
#endif
/*
* 0. Initialize the RNG and the session data
*/
mbedtls_net_init( &server_fd );
mbedtls_ssl_init( &ssl );
mbedtls_ssl_config_init( &conf );
mbedtls_x509_crt_init( &cacert );
mbedtls_ctr_drbg_init( &ctr_drbg );
mbedtls_printf( "\n . Seeding the random number generator..." );
fflush( stdout );
mbedtls_entropy_init( &entropy );
if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
(const unsigned char *) pers,
strlen( pers ) ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ctr_drbg_seed returned %d\n", ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* 0. Load certificates
*/
mbedtls_printf( " . Loading the CA root certificate ..." );
fflush( stdout );
ret = mbedtls_x509_crt_parse( &cacert, (const unsigned char *) mbedtls_test_cas_pem,
mbedtls_test_cas_pem_len );
if( ret < 0 )
{
mbedtls_printf( " failed\n ! mbedtls_x509_crt_parse returned -0x%x\n\n", -ret );
goto exit;
}
mbedtls_printf( " ok (%d skipped)\n", ret );
/*
* 1. Start the connection
*/
mbedtls_printf( " . Connecting to udp/%s/%s...", SERVER_NAME, SERVER_PORT );
fflush( stdout );
if( ( ret = mbedtls_net_connect( &server_fd, SERVER_ADDR,
SERVER_PORT, MBEDTLS_NET_PROTO_UDP ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_net_connect returned %d\n\n", ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* 2. Setup stuff
*/
mbedtls_printf( " . Setting up the DTLS structure..." );
fflush( stdout );
if( ( ret = mbedtls_ssl_config_defaults( &conf,
MBEDTLS_SSL_IS_CLIENT,
MBEDTLS_SSL_TRANSPORT_DATAGRAM,
MBEDTLS_SSL_PRESET_DEFAULT ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_config_defaults returned %d\n\n", ret );
goto exit;
}
/* OPTIONAL is usually a bad choice for security, but makes interop easier
* in this simplified example, in which the ca chain is hardcoded.
* Production code should set a proper ca chain and use REQUIRED. */
mbedtls_ssl_conf_authmode( &conf, MBEDTLS_SSL_VERIFY_OPTIONAL );
mbedtls_ssl_conf_ca_chain( &conf, &cacert, NULL );
mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &ctr_drbg );
mbedtls_ssl_conf_dbg( &conf, my_debug, stdout );
if( ( ret = mbedtls_ssl_setup( &ssl, &conf ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_setup returned %d\n\n", ret );
goto exit;
}
if( ( ret = mbedtls_ssl_set_hostname( &ssl, SERVER_NAME ) ) != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_set_hostname returned %d\n\n", ret );
goto exit;
}
mbedtls_ssl_set_bio( &ssl, &server_fd,
mbedtls_net_send, mbedtls_net_recv, mbedtls_net_recv_timeout );
mbedtls_ssl_set_timer_cb( &ssl, &timer, mbedtls_timing_set_delay,
mbedtls_timing_get_delay );
mbedtls_printf( " ok\n" );
/*
* 4. Handshake
*/
mbedtls_printf( " . Performing the SSL/TLS handshake..." );
fflush( stdout );
do ret = mbedtls_ssl_handshake( &ssl );
while( ret == MBEDTLS_ERR_SSL_WANT_READ ||
ret == MBEDTLS_ERR_SSL_WANT_WRITE );
if( ret != 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_handshake returned -0x%x\n\n", -ret );
goto exit;
}
mbedtls_printf( " ok\n" );
/*
* 5. Verify the server certificate
*/
mbedtls_printf( " . Verifying peer X.509 certificate..." );
/* In real life, we would have used MBEDTLS_SSL_VERIFY_REQUIRED so that the
* handshake would not succeed if the peer's cert is bad. Even if we used
* MBEDTLS_SSL_VERIFY_OPTIONAL, we would bail out here if ret != 0 */
if( ( flags = mbedtls_ssl_get_verify_result( &ssl ) ) != 0 )
{
char vrfy_buf[512];
mbedtls_printf( " failed\n" );
mbedtls_x509_crt_verify_info( vrfy_buf, sizeof( vrfy_buf ), " ! ", flags );
mbedtls_printf( "%s\n", vrfy_buf );
}
else
mbedtls_printf( " ok\n" );
/*
* 6. Write the echo request
*/
send_request:
mbedtls_printf( " > Write to server:" );
fflush( stdout );
len = sizeof( MESSAGE ) - 1;
do ret = mbedtls_ssl_write( &ssl, (unsigned char *) MESSAGE, len );
while( ret == MBEDTLS_ERR_SSL_WANT_READ ||
ret == MBEDTLS_ERR_SSL_WANT_WRITE );
if( ret < 0 )
{
mbedtls_printf( " failed\n ! mbedtls_ssl_write returned %d\n\n", ret );
goto exit;
}
len = ret;
mbedtls_printf( " %d bytes written\n\n%s\n\n", len, MESSAGE );
/*
* 7. Read the echo response
*/
mbedtls_printf( " < Read from server:" );
fflush( stdout );
len = sizeof( buf ) - 1;
memset( buf, 0, sizeof( buf ) );
do ret = mbedtls_ssl_read( &ssl, buf, len );
while( ret == MBEDTLS_ERR_SSL_WANT_READ ||
ret == MBEDTLS_ERR_SSL_WANT_WRITE );
if( ret <= 0 )
{
switch( ret )
{
case MBEDTLS_ERR_SSL_TIMEOUT:
mbedtls_printf( " timeout\n\n" );
if( retry_left-- > 0 )
goto send_request;
goto exit;
case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY:
mbedtls_printf( " connection was closed gracefully\n" );
ret = 0;
goto close_notify;
default:
mbedtls_printf( " mbedtls_ssl_read returned -0x%x\n\n", -ret );
goto exit;
}
}
len = ret;
mbedtls_printf( " %d bytes read\n\n%s\n\n", len, buf );
/*
* 8. Done, cleanly close the connection
*/
close_notify:
mbedtls_printf( " . Closing the connection..." );
/* No error checking, the connection might be closed already */
do ret = mbedtls_ssl_close_notify( &ssl );
while( ret == MBEDTLS_ERR_SSL_WANT_WRITE );
ret = 0;
mbedtls_printf( " done\n" );
/*
* 9. Final clean-ups and exit
*/
exit:
#ifdef MBEDTLS_ERROR_C
if( ret != 0 )
{
char error_buf[100];
mbedtls_strerror( ret, error_buf, 100 );
mbedtls_printf( "Last error was: %d - %s\n\n", ret, error_buf );
}
#endif
mbedtls_net_free( &server_fd );
mbedtls_x509_crt_free( &cacert );
mbedtls_ssl_free( &ssl );
mbedtls_ssl_config_free( &conf );
mbedtls_ctr_drbg_free( &ctr_drbg );
mbedtls_entropy_free( &entropy );
#if defined(_WIN32)
mbedtls_printf( " + Press Enter to exit this program.\n" );
fflush( stdout ); getchar();
#endif
/* Shell can not handle large exit numbers -> 1 for errors */
if( ret < 0 )
ret = 1;
return( ret );
}
#endif /* MBEDTLS_SSL_CLI_C && MBEDTLS_SSL_PROTO_DTLS && MBEDTLS_NET_C &&
MBEDTLD_TIMING_C && MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C &&
MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_RSA_C && MBEDTLS_CERTS_C &&
MBEDTLS_PEM_PARSE_C */