text: /*
   *  SSL client demonstration program
   *
   *  Copyright The Mbed TLS Contributors
   *  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.
   */
  
  #include "mbedtls/build_info.h"
  
  #if defined(MBEDTLS_PLATFORM_C)
  #include "mbedtls/platform.h"
  #else
  #include <stdio.h>
  #include <stdlib.h>
  #define mbedtls_time            time
  #define mbedtls_time_t          time_t
  #define mbedtls_fprintf         fprintf
  #define mbedtls_printf          printf
  #define mbedtls_exit            exit
  #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
  #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
  #endif /* MBEDTLS_PLATFORM_C */
  
  #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_ENTROPY_C) ||     \
      !defined(MBEDTLS_SSL_TLS_C) || !defined(MBEDTLS_SSL_CLI_C) ||    \
      !defined(MBEDTLS_NET_C) || !defined(MBEDTLS_RSA_C) ||            \
      !defined(MBEDTLS_PEM_PARSE_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
      !defined(MBEDTLS_X509_CRT_PARSE_C)
  int main( void )
  {
      mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C and/or "
             "MBEDTLS_SSL_TLS_C and/or MBEDTLS_SSL_CLI_C and/or "
             "MBEDTLS_NET_C and/or MBEDTLS_RSA_C and/or "
             "MBEDTLS_CTR_DRBG_C and/or MBEDTLS_X509_CRT_PARSE_C "
             "not defined.\n");
      mbedtls_exit( 0 );
  }
  #else
  
  #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 "test/certs.h"
  
  #include <string.h>
  
  #define SERVER_PORT "4433"
  #define SERVER_NAME "localhost"
  #define GET_REQUEST "GET / HTTP/1.0\r\n\r\n"
  
  #define DEBUG_LEVEL 1
  
  
  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( void )
  {
      int ret = 1, len;
      int exit_code = MBEDTLS_EXIT_FAILURE;
      mbedtls_net_context server_fd;
      uint32_t flags;
      unsigned char buf[1024];
      const char *pers = "ssl_client1";
  
      mbedtls_entropy_context entropy;
      mbedtls_ctr_drbg_context ctr_drbg;
      mbedtls_ssl_context ssl;
      mbedtls_ssl_config conf;
      mbedtls_x509_crt cacert;
  
  #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. Initialize 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", (unsigned int) -ret );
          goto exit;
      }
  
      mbedtls_printf( " ok (%d skipped)\n", ret );
  
      /*
       * 1. Start the connection
       */
      mbedtls_printf( "  . Connecting to tcp/%s/%s...", SERVER_NAME, SERVER_PORT );
      fflush( stdout );
  
      if( ( ret = mbedtls_net_connect( &server_fd, SERVER_NAME,
                                           SERVER_PORT, MBEDTLS_NET_PROTO_TCP ) ) != 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 SSL/TLS structure..." );
      fflush( stdout );
  
      if( ( ret = mbedtls_ssl_config_defaults( &conf,
                      MBEDTLS_SSL_IS_CLIENT,
                      MBEDTLS_SSL_TRANSPORT_STREAM,
                      MBEDTLS_SSL_PRESET_DEFAULT ) ) != 0 )
      {
          mbedtls_printf( " failed\n  ! mbedtls_ssl_config_defaults returned %d\n\n", ret );
          goto exit;
      }
  
      mbedtls_printf( " ok\n" );
  
      /* OPTIONAL is not optimal for security,
       * but makes interop easier in this simplified example */
      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, NULL );
  
      /*
       * 4. Handshake
       */
      mbedtls_printf( "  . Performing the SSL/TLS handshake..." );
      fflush( stdout );
  
      while( ( ret = mbedtls_ssl_handshake( &ssl ) ) != 0 )
      {
          if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
          {
              mbedtls_printf( " failed\n  ! mbedtls_ssl_handshake returned -0x%x\n\n", (unsigned int) -ret );
              goto exit;
          }
      }
  
      mbedtls_printf( " ok\n" );
  
      /*
       * 5. Verify the server certificate
       */
      mbedtls_printf( "  . Verifying peer X.509 certificate..." );
  
      /* In real life, we probably want to bail out when ret != 0 */
      if( ( flags = mbedtls_ssl_get_verify_result( &ssl ) ) != 0 )
      {
  #if !defined(MBEDTLS_X509_REMOVE_INFO)
          char vrfy_buf[512];
  #endif
  
          mbedtls_printf( " failed\n" );
  
  #if !defined(MBEDTLS_X509_REMOVE_INFO)
          mbedtls_x509_crt_verify_info( vrfy_buf, sizeof( vrfy_buf ), "  ! ", flags );
  
          mbedtls_printf( "%s\n", vrfy_buf );
  #endif
      }
      else
          mbedtls_printf( " ok\n" );
  
      /*
       * 3. Write the GET request
       */
      mbedtls_printf( "  > Write to server:" );
      fflush( stdout );
  
      len = sprintf( (char *) buf, GET_REQUEST );
  
      while( ( ret = mbedtls_ssl_write( &ssl, buf, len ) ) <= 0 )
      {
          if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
          {
              mbedtls_printf( " failed\n  ! mbedtls_ssl_write returned %d\n\n", ret );
              goto exit;
          }
      }
  
      len = ret;
      mbedtls_printf( " %d bytes written\n\n%s", len, (char *) buf );
  
      /*
       * 7. Read the HTTP response
       */
      mbedtls_printf( "  < Read from server:" );
      fflush( stdout );
  
      do
      {
          len = sizeof( buf ) - 1;
          memset( buf, 0, sizeof( buf ) );
          ret = mbedtls_ssl_read( &ssl, buf, len );
  
          if( ret == MBEDTLS_ERR_SSL_WANT_READ || ret == MBEDTLS_ERR_SSL_WANT_WRITE )
              continue;
  
          if( ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY )
              break;
  
          if( ret < 0 )
          {
              mbedtls_printf( "failed\n  ! mbedtls_ssl_read returned %d\n\n", ret );
              break;
          }
  
          if( ret == 0 )
          {
              mbedtls_printf( "\n\nEOF\n\n" );
              break;
          }
  
          len = ret;
          mbedtls_printf( " %d bytes read\n\n%s", len, (char *) buf );
      }
      while( 1 );
  
      mbedtls_ssl_close_notify( &ssl );
  
      exit_code = MBEDTLS_EXIT_SUCCESS;
  
  exit:
  
  #ifdef MBEDTLS_ERROR_C
      if( exit_code != MBEDTLS_EXIT_SUCCESS )
      {
          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 );
  
      mbedtls_exit( exit_code );
  }
  #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_SSL_TLS_C &&
            MBEDTLS_SSL_CLI_C && MBEDTLS_NET_C && MBEDTLS_RSA_C &&
            MBEDTLS_PEM_PARSE_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_X509_CRT_PARSE_C */
  