text: /*
   *  SSL server demonstration program using fork() for handling multiple clients
   *
   *  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.
   */
  
  #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>
  #include <stdlib.h>
  #define mbedtls_fprintf         fprintf
  #define mbedtls_printf          printf
  #define mbedtls_time_t          time_t
  #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_SRV_C) ||         \
      !defined(MBEDTLS_NET_C) || !defined(MBEDTLS_RSA_C) ||                 \
      !defined(MBEDTLS_CTR_DRBG_C) || !defined(MBEDTLS_X509_CRT_PARSE_C) || \
      !defined(MBEDTLS_TIMING_C) || !defined(MBEDTLS_FS_IO) ||              \
      !defined(MBEDTLS_PEM_PARSE_C)
  int main( int argc, char *argv[] )
  {
      ((void) argc);
      ((void) argv);
  
      mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_ENTROPY_C "
             "and/or MBEDTLS_SSL_TLS_C and/or MBEDTLS_SSL_SRV_C and/or "
             "MBEDTLS_NET_C and/or MBEDTLS_RSA_C and/or "
             "MBEDTLS_CTR_DRBG_C and/or MBEDTLS_X509_CRT_PARSE_C and/or "
             "MBEDTLS_TIMING_C and/or MBEDTLS_PEM_PARSE_C not defined.\n");
      mbedtls_exit( 0 );
  }
  #elif defined(_WIN32)
  int main( void )
  {
      mbedtls_printf("_WIN32 defined. This application requires fork() and signals "
             "to work correctly.\n");
      mbedtls_exit( 0 );
  }
  #else
  
  #include "mbedtls/entropy.h"
  #include "mbedtls/ctr_drbg.h"
  #include "test/certs.h"
  #include "mbedtls/x509.h"
  #include "mbedtls/ssl.h"
  #include "mbedtls/net_sockets.h"
  #include "mbedtls/timing.h"
  
  #include <string.h>
  #include <signal.h>
  
  #if !defined(_MSC_VER) || defined(EFIX64) || defined(EFI32)
  #include <unistd.h>
  #endif
  
  #define HTTP_RESPONSE \
      "HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n" \
      "<h2>mbed TLS Test Server</h2>\r\n" \
      "<p>Successful connection using: %s</p>\r\n"
  
  #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( void )
  {
      int ret = 1, len, cnt = 0, pid;
      int exit_code = MBEDTLS_EXIT_FAILURE;
      mbedtls_net_context listen_fd, client_fd;
      unsigned char buf[1024];
      const char *pers = "ssl_fork_server";
  
      mbedtls_entropy_context entropy;
      mbedtls_ctr_drbg_context ctr_drbg;
      mbedtls_ssl_context ssl;
      mbedtls_ssl_config conf;
      mbedtls_x509_crt srvcert;
      mbedtls_pk_context pkey;
  
      mbedtls_net_init( &listen_fd );
      mbedtls_net_init( &client_fd );
      mbedtls_ssl_init( &ssl );
      mbedtls_ssl_config_init( &conf );
      mbedtls_entropy_init( &entropy );
      mbedtls_pk_init( &pkey );
      mbedtls_x509_crt_init( &srvcert );
      mbedtls_ctr_drbg_init( &ctr_drbg );
  
      signal( SIGCHLD, SIG_IGN );
  
      /*
       * 0. Initial seeding of the RNG
       */
      mbedtls_printf( "\n  . Initial seeding of the random generator..." );
      fflush( stdout );
  
      if( ( ret = mbedtls_ctr_drbg_seed( &ctr_drbg, mbedtls_entropy_func, &entropy,
                                 (const unsigned char *) pers,
                                 strlen( pers ) ) ) != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_ctr_drbg_seed returned %d\n\n", ret );
          goto exit;
      }
  
      mbedtls_printf( " ok\n" );
  
      /*
       * 1. Load the certificates and private RSA key
       */
      mbedtls_printf( "  . Loading the server cert. and key..." );
      fflush( stdout );
  
      /*
       * This demonstration program uses embedded test certificates.
       * Instead, you may want to use mbedtls_x509_crt_parse_file() to read the
       * server and CA certificates, as well as mbedtls_pk_parse_keyfile().
       */
      ret = mbedtls_x509_crt_parse( &srvcert, (const unsigned char *) mbedtls_test_srv_crt,
                            mbedtls_test_srv_crt_len );
      if( ret != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_x509_crt_parse returned %d\n\n", ret );
          goto exit;
      }
  
      ret = mbedtls_x509_crt_parse( &srvcert, (const unsigned char *) mbedtls_test_cas_pem,
                            mbedtls_test_cas_pem_len );
      if( ret != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_x509_crt_parse returned %d\n\n", ret );
          goto exit;
      }
  
      ret =  mbedtls_pk_parse_key( &pkey, (const unsigned char *) mbedtls_test_srv_key,
                            mbedtls_test_srv_key_len, NULL, 0 );
      if( ret != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_pk_parse_key returned %d\n\n", ret );
          goto exit;
      }
  
      mbedtls_printf( " ok\n" );
  
      /*
       * 1b. Prepare SSL configuration
       */
      mbedtls_printf( "  . Configuring SSL..." );
      fflush( stdout );
  
      if( ( ret = mbedtls_ssl_config_defaults( &conf,
                      MBEDTLS_SSL_IS_SERVER,
                      MBEDTLS_SSL_TRANSPORT_STREAM,
                      MBEDTLS_SSL_PRESET_DEFAULT ) ) != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_ssl_config_defaults returned %d\n\n", ret );
          goto exit;
      }
  
      mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &ctr_drbg );
      mbedtls_ssl_conf_dbg( &conf, my_debug, stdout );
  
      mbedtls_ssl_conf_ca_chain( &conf, srvcert.next, NULL );
      if( ( ret = mbedtls_ssl_conf_own_cert( &conf, &srvcert, &pkey ) ) != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_ssl_conf_own_cert returned %d\n\n", ret );
          goto exit;
      }
  
      mbedtls_printf( " ok\n" );
  
      /*
       * 2. Setup the listening TCP socket
       */
      mbedtls_printf( "  . Bind on https://localhost:4433/ ..." );
      fflush( stdout );
  
      if( ( ret = mbedtls_net_bind( &listen_fd, NULL, "4433", MBEDTLS_NET_PROTO_TCP ) ) != 0 )
      {
          mbedtls_printf( " failed!  mbedtls_net_bind returned %d\n\n", ret );
          goto exit;
      }
  
      mbedtls_printf( " ok\n" );
  
      while( 1 )
      {
          /*
           * 3. Wait until a client connects
           */
          mbedtls_net_init( &client_fd );
          mbedtls_ssl_init( &ssl );
  
          mbedtls_printf( "  . Waiting for a remote connection ...\n" );
          fflush( stdout );
  
          if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
                                          NULL, 0, NULL ) ) != 0 )
          {
              mbedtls_printf( " failed!  mbedtls_net_accept returned %d\n\n", ret );
              goto exit;
          }
  
          /*
           * 3.5. Forking server thread
           */
  
          mbedtls_printf( "  . Forking to handle connection ..." );
          fflush( stdout );
  
          pid = fork();
  
          if( pid < 0 )
          {
              mbedtls_printf(" failed!  fork returned %d\n\n", pid );
              goto exit;
          }
  
          if( pid != 0 )
          {
              mbedtls_printf( " ok\n" );
              mbedtls_net_close( &client_fd );
  
              if( ( ret = mbedtls_ctr_drbg_reseed( &ctr_drbg,
                                           (const unsigned char *) "parent",
                                           6 ) ) != 0 )
              {
                  mbedtls_printf( " failed!  mbedtls_ctr_drbg_reseed returned %d\n\n", ret );
                  goto exit;
              }
  
              continue;
          }
  
          mbedtls_net_close( &listen_fd );
  
          pid = getpid();
  
          /*
           * 4. Setup stuff
           */
          mbedtls_printf( "pid %d: Setting up the SSL data.\n", pid );
          fflush( stdout );
  
          if( ( ret = mbedtls_ctr_drbg_reseed( &ctr_drbg,
                                       (const unsigned char *) "child",
                                       5 ) ) != 0 )
          {
              mbedtls_printf(
                      "pid %d: SSL setup failed!  mbedtls_ctr_drbg_reseed returned %d\n\n",
                      pid, ret );
              goto exit;
          }
  
          if( ( ret = mbedtls_ssl_setup( &ssl, &conf ) ) != 0 )
          {
              mbedtls_printf(
                      "pid %d: SSL setup failed!  mbedtls_ssl_setup returned %d\n\n",
                      pid, ret );
              goto exit;
          }
  
          mbedtls_ssl_set_bio( &ssl, &client_fd, mbedtls_net_send, mbedtls_net_recv, NULL );
  
          mbedtls_printf( "pid %d: SSL setup ok\n", pid );
  
          /*
           * 5. Handshake
           */
          mbedtls_printf( "pid %d: Performing the SSL/TLS handshake.\n", pid );
          fflush( stdout );
  
          while( ( ret = mbedtls_ssl_handshake( &ssl ) ) != 0 )
          {
              if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
              {
                  mbedtls_printf(
                          "pid %d: SSL handshake failed!  mbedtls_ssl_handshake returned %d\n\n",
                          pid, ret );
                  goto exit;
              }
          }
  
          mbedtls_printf( "pid %d: SSL handshake ok\n", pid );
  
          /*
           * 6. Read the HTTP Request
           */
          mbedtls_printf( "pid %d: Start reading from client.\n", pid );
          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 <= 0 )
              {
                  switch( ret )
                  {
                      case MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY:
                          mbedtls_printf( "pid %d: connection was closed gracefully\n", pid );
                          break;
  
                      case MBEDTLS_ERR_NET_CONN_RESET:
                          mbedtls_printf( "pid %d: connection was reset by peer\n", pid );
                          break;
  
                      default:
                          mbedtls_printf( "pid %d: mbedtls_ssl_read returned %d\n", pid, ret );
                          break;
                  }
  
                  break;
              }
  
              len = ret;
              mbedtls_printf( "pid %d: %d bytes read\n\n%s", pid, len, (char *) buf );
  
              if( ret > 0 )
                  break;
          }
          while( 1 );
  
          /*
           * 7. Write the 200 Response
           */
          mbedtls_printf( "pid %d: Start writing to client.\n", pid );
          fflush( stdout );
  
          len = sprintf( (char *) buf, HTTP_RESPONSE,
                  mbedtls_ssl_get_ciphersuite( &ssl ) );
  
          while( cnt++ < 100 )
          {
              while( ( ret = mbedtls_ssl_write( &ssl, buf, len ) ) <= 0 )
              {
                  if( ret == MBEDTLS_ERR_NET_CONN_RESET )
                  {
                      mbedtls_printf(
                              "pid %d: Write failed!  peer closed the connection\n\n", pid );
                      goto exit;
                  }
  
                  if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
                  {
                      mbedtls_printf(
                              "pid %d: Write failed!  mbedtls_ssl_write returned %d\n\n",
                              pid, ret );
                      goto exit;
                  }
              }
              len = ret;
              mbedtls_printf( "pid %d: %d bytes written\n\n%s\n", pid, len, (char *) buf );
  
              mbedtls_net_usleep( 1000000 );
          }
  
          mbedtls_ssl_close_notify( &ssl );
          goto exit;
      }
  
      exit_code = MBEDTLS_EXIT_SUCCESS;
  
  exit:
      mbedtls_net_free( &client_fd );
      mbedtls_net_free( &listen_fd );
  
      mbedtls_x509_crt_free( &srvcert );
      mbedtls_pk_free( &pkey );
      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
  
      mbedtls_exit( exit_code );
  }
  #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_ENTROPY_C &&
            MBEDTLS_SSL_TLS_C && MBEDTLS_SSL_SRV_C && MBEDTLS_NET_C &&
            MBEDTLS_RSA_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_PEM_PARSE_C &&
            ! _WIN32 */
  