| /* |
| * Simple DTLS client demonstration program |
| * |
| * Copyright (C) 2014, Brainspark B.V. |
| * |
| * This file is part of mbed TLS (https://polarssl.org) |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License along |
| * with this program; if not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| #if !defined(POLARSSL_CONFIG_FILE) |
| #include "polarssl/config.h" |
| #else |
| #include POLARSSL_CONFIG_FILE |
| #endif |
| |
| #if !defined(POLARSSL_SSL_CLI_C) || !defined(POLARSSL_SSL_PROTO_DTLS) || \ |
| !defined(POLARSSL_NET_C) || \ |
| !defined(POLARSSL_ENTROPY_C) || !defined(POLARSSL_CTR_DRBG_C) || \ |
| !defined(POLARSSL_X509_CRT_PARSE_C) || !defined(POLARSSL_RSA_C) || \ |
| !defined(POLARSSL_CERTS_C) |
| |
| #include <stdio.h> |
| int main( int argc, char *argv[] ) |
| { |
| ((void) argc); |
| ((void) argv); |
| |
| printf( "POLARSSL_SSL_CLI_C and/or POLARSSL_SSL_PROTO_DTLS and/or " |
| "POLARSSL_NET_C and/or " |
| "POLARSSL_ENTROPY_C and/or POLARSSL_CTR_DRBG_C and/or " |
| "POLARSSL_X509_CRT_PARSE_C and/or POLARSSL_RSA_C and/or " |
| "POLARSSL_CERTS_C not defined.\n" ); |
| return( 0 ); |
| } |
| #else |
| |
| #include <string.h> |
| #include <stdio.h> |
| |
| #include "polarssl/net.h" |
| #include "polarssl/debug.h" |
| #include "polarssl/ssl.h" |
| #include "polarssl/entropy.h" |
| #include "polarssl/ctr_drbg.h" |
| #include "polarssl/error.h" |
| #include "polarssl/certs.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 *str ) |
| { |
| ((void) level); |
| |
| fprintf( (FILE *) ctx, "%s", str ); |
| fflush( (FILE *) ctx ); |
| } |
| |
| int main( int argc, char *argv[] ) |
| { |
| int ret, len, server_fd = -1; |
| unsigned char buf[1024]; |
| const char *pers = "dtls_client"; |
| int retry_left = MAX_RETRY; |
| |
| entropy_context entropy; |
| ctr_drbg_context ctr_drbg; |
| ssl_context ssl; |
| x509_crt cacert; |
| |
| ((void) argc); |
| ((void) argv); |
| |
| #if defined(POLARSSL_DEBUG_C) |
| debug_set_threshold( DEBUG_LEVEL ); |
| #endif |
| |
| /* |
| * 0. Initialize the RNG and the session data |
| */ |
| memset( &ssl, 0, sizeof( ssl_context ) ); |
| x509_crt_init( &cacert ); |
| |
| printf( "\n . Seeding the random number generator..." ); |
| fflush( stdout ); |
| |
| entropy_init( &entropy ); |
| if( ( ret = ctr_drbg_init( &ctr_drbg, entropy_func, &entropy, |
| (const unsigned char *) pers, |
| strlen( pers ) ) ) != 0 ) |
| { |
| printf( " failed\n ! ctr_drbg_init returned %d\n", ret ); |
| goto exit; |
| } |
| |
| printf( " ok\n" ); |
| |
| /* |
| * 0. Initialize certificates |
| */ |
| printf( " . Loading the CA root certificate ..." ); |
| fflush( stdout ); |
| |
| #if defined(POLARSSL_CERTS_C) |
| ret = x509_crt_parse( &cacert, (const unsigned char *) test_ca_list, |
| strlen( test_ca_list ) ); |
| #else |
| ret = 1; |
| printf("POLARSSL_CERTS_C not defined."); |
| #endif |
| |
| if( ret < 0 ) |
| { |
| printf( " failed\n ! x509_crt_parse returned -0x%x\n\n", -ret ); |
| goto exit; |
| } |
| |
| printf( " ok (%d skipped)\n", ret ); |
| |
| /* |
| * 1. Start the connection |
| */ |
| printf( " . Connecting to udp/%s/%4d...", SERVER_NAME, |
| SERVER_PORT ); |
| fflush( stdout ); |
| |
| if( ( ret = net_connect( &server_fd, SERVER_ADDR, |
| SERVER_PORT, NET_PROTO_UDP ) ) != 0 ) |
| { |
| printf( " failed\n ! net_connect returned %d\n\n", ret ); |
| goto exit; |
| } |
| |
| printf( " ok\n" ); |
| |
| /* |
| * 2. Setup stuff |
| */ |
| printf( " . Setting up the DTLS structure..." ); |
| fflush( stdout ); |
| |
| if( ( ret = ssl_init( &ssl ) ) != 0 ) |
| { |
| printf( " failed\n ! ssl_init returned %d\n\n", ret ); |
| goto exit; |
| } |
| |
| printf( " ok\n" ); |
| |
| ssl_set_endpoint( &ssl, SSL_IS_CLIENT ); |
| ssl_set_transport( &ssl, SSL_TRANSPORT_DATAGRAM ); |
| |
| /* 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. */ |
| ssl_set_authmode( &ssl, SSL_VERIFY_OPTIONAL ); |
| ssl_set_ca_chain( &ssl, &cacert, NULL, SERVER_NAME ); |
| |
| ssl_set_rng( &ssl, ctr_drbg_random, &ctr_drbg ); |
| ssl_set_dbg( &ssl, my_debug, stdout ); |
| |
| ssl_set_bio_timeout( &ssl, &server_fd, |
| net_send, net_recv, net_recv_timeout, |
| READ_TIMEOUT_MS ); |
| |
| /* |
| * 4. Handshake |
| */ |
| printf( " . Performing the SSL/TLS handshake..." ); |
| fflush( stdout ); |
| |
| do ret = ssl_handshake( &ssl ); |
| while( ret == POLARSSL_ERR_NET_WANT_READ || |
| ret == POLARSSL_ERR_NET_WANT_WRITE ); |
| |
| if( ret != 0 ) |
| { |
| printf( " failed\n ! ssl_handshake returned -0x%x\n\n", -ret ); |
| goto exit; |
| } |
| |
| printf( " ok\n" ); |
| |
| /* |
| * 5. Verify the server certificate |
| */ |
| printf( " . Verifying peer X.509 certificate..." ); |
| |
| /* In real life, we would have used SSL_VERIFY_REQUIRED so that the |
| * handshake would not succeed if the peer's cert is bad. Even if we used |
| * SSL_VERIFY_OPTIONAL, we would bail out here if ret != 0 */ |
| if( ( ret = ssl_get_verify_result( &ssl ) ) != 0 ) |
| { |
| printf( " failed\n" ); |
| |
| if( ( ret & BADCERT_EXPIRED ) != 0 ) |
| printf( " ! server certificate has expired\n" ); |
| |
| if( ( ret & BADCERT_REVOKED ) != 0 ) |
| printf( " ! server certificate has been revoked\n" ); |
| |
| if( ( ret & BADCERT_CN_MISMATCH ) != 0 ) |
| printf( " ! CN mismatch (expected CN=%s)\n", SERVER_NAME ); |
| |
| if( ( ret & BADCERT_NOT_TRUSTED ) != 0 ) |
| printf( " ! self-signed or not signed by a trusted CA\n" ); |
| |
| printf( "\n" ); |
| } |
| else |
| printf( " ok\n" ); |
| |
| /* |
| * 6. Write the echo request |
| */ |
| send_request: |
| printf( " > Write to server:" ); |
| fflush( stdout ); |
| |
| len = sizeof( MESSAGE ) - 1; |
| |
| do ret = ssl_write( &ssl, (unsigned char *) MESSAGE, len ); |
| while( ret == POLARSSL_ERR_NET_WANT_READ || |
| ret == POLARSSL_ERR_NET_WANT_WRITE ); |
| |
| if( ret < 0 ) |
| { |
| printf( " failed\n ! ssl_write returned %d\n\n", ret ); |
| goto exit; |
| } |
| |
| len = ret; |
| printf( " %d bytes written\n\n%s\n\n", len, MESSAGE ); |
| |
| /* |
| * 7. Read the echo response |
| */ |
| printf( " < Read from server:" ); |
| fflush( stdout ); |
| |
| len = sizeof( buf ) - 1; |
| memset( buf, 0, sizeof( buf ) ); |
| |
| do ret = ssl_read( &ssl, buf, len ); |
| while( ret == POLARSSL_ERR_NET_WANT_READ || |
| ret == POLARSSL_ERR_NET_WANT_WRITE ); |
| |
| if( ret <= 0 ) |
| { |
| switch( ret ) |
| { |
| case POLARSSL_ERR_NET_TIMEOUT: |
| printf( " timeout\n\n" ); |
| if( retry_left-- > 0 ) |
| goto send_request; |
| goto exit; |
| |
| case POLARSSL_ERR_SSL_PEER_CLOSE_NOTIFY: |
| printf( " connection was closed gracefully\n" ); |
| ret = 0; |
| goto close_notify; |
| |
| default: |
| printf( " ssl_read returned -0x%x\n\n", -ret ); |
| goto exit; |
| } |
| } |
| |
| len = ret; |
| printf( " %d bytes read\n\n%s\n\n", len, buf ); |
| |
| /* |
| * 8. Done, cleanly close the connection |
| */ |
| close_notify: |
| printf( " . Closing the connection..." ); |
| |
| /* No error checking, the connection might be closed already */ |
| do ret = ssl_close_notify( &ssl ); |
| while( ret == POLARSSL_ERR_NET_WANT_WRITE ); |
| ret = 0; |
| |
| printf( " done\n" ); |
| |
| /* |
| * 9. Final clean-ups and exit |
| */ |
| exit: |
| |
| #ifdef POLARSSL_ERROR_C |
| if( ret != 0 ) |
| { |
| char error_buf[100]; |
| polarssl_strerror( ret, error_buf, 100 ); |
| printf( "Last error was: %d - %s\n\n", ret, error_buf ); |
| } |
| #endif |
| |
| if( server_fd != -1 ) |
| net_close( server_fd ); |
| |
| x509_crt_free( &cacert ); |
| ssl_free( &ssl ); |
| ctr_drbg_free( &ctr_drbg ); |
| entropy_free( &entropy ); |
| |
| #if defined(_WIN32) |
| 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 /* POLARSSL_SSL_CLI_C && POLARSSL_SSL_PROTO_DTLS && POLARSSL_NET_C && |
| POLARSSL_ENTROPY_C && POLARSSL_CTR_DRBG_C && |
| POLARSSL_X509_CRT_PARSE_C && POLARSSL_RSA_C && POLARSSL_CERTS_C */ |