| 123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350 | /* *  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_sockets.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 0static 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 */
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