programs/ssl/ssl_pthread_server.c - security/mbedtls - Rivoreo Source Code Repositories

 /*
  *  SSL server demonstration program using pthread for handling multiple
  *  clients.
  *
  *  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_fprintf    fprintf
 #define mbedtls_printf     printf
 #define mbedtls_snprintf   snprintf
 #endif

 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_CERTS_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_FS_IO) ||      \
     !defined(MBEDTLS_THREADING_C) || !defined(MBEDTLS_THREADING_PTHREAD) || \
     !defined(MBEDTLS_PEM_PARSE_C)
 int main( void )
 {
     mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_CERTS_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_THREADING_C and/or MBEDTLS_THREADING_PTHREAD "
            "and/or MBEDTLS_PEM_PARSE_C not defined.\n");
     return( 0 );
 }
 #else

 #include <stdlib.h>
 #include <string.h>

 #if defined(_WIN32)
 #include <windows.h>
 #endif

 #include "mbedtls/entropy.h"
 #include "mbedtls/ctr_drbg.h"
 #include "mbedtls/certs.h"
 #include "mbedtls/x509.h"
 #include "mbedtls/ssl.h"
 #include "mbedtls/net.h"
 #include "mbedtls/error.h"

 #if defined(MBEDTLS_SSL_CACHE_C)
 #include "mbedtls/ssl_cache.h"
 #endif

 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
 #include "mbedtls/memory_buffer_alloc.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

 #define MAX_NUM_THREADS 5

 mbedtls_threading_mutex_t debug_mutex;

 static void my_mutexed_debug( void *ctx, int level,
                       const char *file, int line,
                       const char *str )
 {
     long int thread_id = (long int) pthread_self();

     mbedtls_mutex_lock( &debug_mutex );

     ((void) level);
     mbedtls_fprintf( (FILE *) ctx, "%s:%04d: [ #%ld ] %s",
                                     file, line, thread_id, str );
     fflush(  (FILE *) ctx  );

     mbedtls_mutex_unlock( &debug_mutex );
 }

 typedef struct {
     mbedtls_net_context client_fd;
     int thread_complete;
     const mbedtls_ssl_config *config;
 } thread_info_t;

 typedef struct {
     int active;
     thread_info_t   data;
     pthread_t       thread;
 } pthread_info_t;

 static thread_info_t    base_info;
 static pthread_info_t   threads[MAX_NUM_THREADS];

 static void *handle_ssl_connection( void *data )
 {
     int ret, len;
     thread_info_t *thread_info = (thread_info_t *) data;
     mbedtls_net_context *client_fd = &thread_info->client_fd;
     long int thread_id = (long int) pthread_self();
     unsigned char buf[1024];
     mbedtls_ssl_context ssl;

     /* Make sure memory references are valid */
     mbedtls_ssl_init( &ssl );

     mbedtls_printf( "  [ #%ld ]  Setting up SSL/TLS data\n", thread_id );

     /*
      * 4. Get the SSL context ready
      */
     if( ( ret = mbedtls_ssl_setup( &ssl, thread_info->config ) ) != 0 )
     {
         mbedtls_printf( "  [ #%ld ]  failed: mbedtls_ssl_setup returned -0x%04x\n",
                 thread_id, -ret );
         goto thread_exit;
     }

     mbedtls_ssl_set_bio( &ssl, client_fd, mbedtls_net_send, mbedtls_net_recv, NULL );

     /*
      * 5. Handshake
      */
     mbedtls_printf( "  [ #%ld ]  Performing the SSL/TLS handshake\n", thread_id );

     while( ( ret = mbedtls_ssl_handshake( &ssl ) ) != 0 )
     {
         if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
         {
             mbedtls_printf( "  [ #%ld ]  failed: mbedtls_ssl_handshake returned -0x%04x\n",
                     thread_id, -ret );
             goto thread_exit;
         }
     }

     mbedtls_printf( "  [ #%ld ]  ok\n", thread_id );

     /*
      * 6. Read the HTTP Request
      */
     mbedtls_printf( "  [ #%ld ]  < Read from client\n", thread_id );

     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( "  [ #%ld ]  connection was closed gracefully\n",
                             thread_id );
                     goto thread_exit;

                 case MBEDTLS_ERR_NET_CONN_RESET:
                     mbedtls_printf( "  [ #%ld ]  connection was reset by peer\n",
                             thread_id );
                     goto thread_exit;

                 default:
                     mbedtls_printf( "  [ #%ld ]  mbedtls_ssl_read returned -0x%04x\n",
                             thread_id, -ret );
                     goto thread_exit;
             }
         }

         len = ret;
         mbedtls_printf( "  [ #%ld ]  %d bytes read\n=====\n%s\n=====\n",
                 thread_id, len, (char *) buf );

         if( ret > 0 )
             break;
     }
     while( 1 );

     /*
      * 7. Write the 200 Response
      */
     mbedtls_printf( "  [ #%ld ]  > Write to client:\n", thread_id );

     len = sprintf( (char *) buf, HTTP_RESPONSE,
                    mbedtls_ssl_get_ciphersuite( &ssl ) );

     while( ( ret = mbedtls_ssl_write( &ssl, buf, len ) ) <= 0 )
     {
         if( ret == MBEDTLS_ERR_NET_CONN_RESET )
         {
             mbedtls_printf( "  [ #%ld ]  failed: peer closed the connection\n",
                     thread_id );
             goto thread_exit;
         }

         if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
         {
             mbedtls_printf( "  [ #%ld ]  failed: mbedtls_ssl_write returned -0x%04x\n",
                     thread_id, ret );
             goto thread_exit;
         }
     }

     len = ret;
     mbedtls_printf( "  [ #%ld ]  %d bytes written\n=====\n%s\n=====\n",
             thread_id, len, (char *) buf );

     mbedtls_printf( "  [ #%ld ]  . Closing the connection...", thread_id );

     while( ( ret = mbedtls_ssl_close_notify( &ssl ) ) < 0 )
     {
         if( ret != MBEDTLS_ERR_SSL_WANT_READ &&
             ret != MBEDTLS_ERR_SSL_WANT_WRITE )
         {
             mbedtls_printf( "  [ #%ld ]  failed: mbedtls_ssl_close_notify returned -0x%04x\n",
                     thread_id, ret );
             goto thread_exit;
         }
     }

     mbedtls_printf( " ok\n" );

     ret = 0;

 thread_exit:

 #ifdef MBEDTLS_ERROR_C
     if( ret != 0 )
     {
         char error_buf[100];
         mbedtls_strerror( ret, error_buf, 100 );
         mbedtls_printf("  [ #%ld ]  Last error was: -0x%04x - %s\n\n",
                thread_id, -ret, error_buf );
     }
 #endif

     mbedtls_net_free( client_fd );
     mbedtls_ssl_free( &ssl );

     thread_info->thread_complete = 1;

     return( NULL );
 }

 static int thread_create( mbedtls_net_context *client_fd )
 {
     int ret, i;

     /*
      * Find in-active or finished thread slot
      */
     for( i = 0; i < MAX_NUM_THREADS; i++ )
     {
         if( threads[i].active == 0 )
             break;

         if( threads[i].data.thread_complete == 1 )
         {
             mbedtls_printf( "  [ main ]  Cleaning up thread %d\n", i );
             pthread_join(threads[i].thread, NULL );
             memset( &threads[i], 0, sizeof(pthread_info_t) );
             break;
         }
     }

     if( i == MAX_NUM_THREADS )
         return( -1 );

     /*
      * Fill thread-info for thread
      */
     memcpy( &threads[i].data, &base_info, sizeof(base_info) );
     threads[i].active = 1;
     memcpy( &threads[i].data.client_fd, client_fd, sizeof( mbedtls_net_context ) );

     if( ( ret = pthread_create( &threads[i].thread, NULL, handle_ssl_connection,
                                 &threads[i].data ) ) != 0 )
     {
         return( ret );
     }

     return( 0 );
 }

 int main( void )
 {
     int ret;
     mbedtls_net_context listen_fd, client_fd;
     const char pers[] = "ssl_pthread_server";

     mbedtls_entropy_context entropy;
     mbedtls_ctr_drbg_context ctr_drbg;
     mbedtls_ssl_config conf;
     mbedtls_x509_crt srvcert;
     mbedtls_x509_crt cachain;
     mbedtls_pk_context pkey;
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
     unsigned char alloc_buf[100000];
 #endif
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_context cache;
 #endif

 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
     mbedtls_memory_buffer_alloc_init( alloc_buf, sizeof(alloc_buf) );
 #endif

 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_init( &cache );
 #endif

     mbedtls_x509_crt_init( &srvcert );
     mbedtls_x509_crt_init( &cachain );

     mbedtls_ssl_config_init( &conf );
     mbedtls_ctr_drbg_init( &ctr_drbg );
     memset( threads, 0, sizeof(threads) );
     mbedtls_net_init( &listen_fd );
     mbedtls_net_init( &client_fd );

     mbedtls_mutex_init( &debug_mutex );

     base_info.config = &conf;

     /*
      * We use only a single entropy source that is used in all the threads.
      */
     mbedtls_entropy_init( &entropy );

     /*
      * 1. Load the certificates and private RSA key
      */
     mbedtls_printf( "\n  . 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\n  !  mbedtls_x509_crt_parse returned %d\n\n", ret );
         goto exit;
     }

     ret = mbedtls_x509_crt_parse( &cachain, (const unsigned char *) mbedtls_test_cas_pem,
                           mbedtls_test_cas_pem_len );
     if( ret != 0 )
     {
         mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse returned %d\n\n", ret );
         goto exit;
     }

     mbedtls_pk_init( &pkey );
     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\n  !  mbedtls_pk_parse_key returned %d\n\n", ret );
         goto exit;
     }

     mbedtls_printf( " ok\n" );

     /*
      * 1b. Seed the random number generator
      */
     mbedtls_printf( "  . Seeding the random number generator..." );

     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 -0x%04x\n",
                 -ret );
         goto exit;
     }

     mbedtls_printf( " ok\n" );

     /*
      * 1c. Prepare SSL configuration
      */
     mbedtls_printf( "  . Setting up the SSL data...." );

     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 -0x%04x\n",
                 -ret );
         goto exit;
     }

     mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &ctr_drbg );
     mbedtls_ssl_conf_dbg( &conf, my_mutexed_debug, stdout );

     /* mbedtls_ssl_cache_get() and mbedtls_ssl_cache_set() are thread-safe if
      * MBEDTLS_THREADING_C is set.
      */
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_conf_session_cache( &conf, &cache,
                                    mbedtls_ssl_cache_get,
                                    mbedtls_ssl_cache_set );
 #endif

     mbedtls_ssl_conf_ca_chain( &conf, &cachain, NULL );
     if( ( ret = mbedtls_ssl_conf_own_cert( &conf, &srvcert, &pkey ) ) != 0 )
     {
         mbedtls_printf( " failed\n  ! 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\n  ! mbedtls_net_bind returned %d\n\n", ret );
         goto exit;
     }

     mbedtls_printf( " ok\n" );

 reset:
 #ifdef MBEDTLS_ERROR_C
     if( ret != 0 )
     {
         char error_buf[100];
         mbedtls_strerror( ret, error_buf, 100 );
         mbedtls_printf( "  [ main ]  Last error was: -0x%04x - %s\n", -ret, error_buf );
     }
 #endif

     /*
      * 3. Wait until a client connects
      */
     mbedtls_printf( "  [ main ]  Waiting for a remote connection\n" );

     if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
                                     NULL, 0, NULL ) ) != 0 )
     {
         mbedtls_printf( "  [ main ] failed: mbedtls_net_accept returned -0x%04x\n", ret );
         goto exit;
     }

     mbedtls_printf( "  [ main ]  ok\n" );
     mbedtls_printf( "  [ main ]  Creating a new thread\n" );

     if( ( ret = thread_create( &client_fd ) ) != 0 )
     {
         mbedtls_printf( "  [ main ]  failed: thread_create returned %d\n", ret );
         mbedtls_net_free( &client_fd );
         goto reset;
     }

     ret = 0;
     goto reset;

 exit:
     mbedtls_x509_crt_free( &srvcert );
     mbedtls_pk_free( &pkey );
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_free( &cache );
 #endif
     mbedtls_ctr_drbg_free( &ctr_drbg );
     mbedtls_entropy_free( &entropy );
     mbedtls_ssl_config_free( &conf );

     mbedtls_net_free( &listen_fd );

     mbedtls_mutex_free( &debug_mutex );

 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
     mbedtls_memory_buffer_alloc_free();
 #endif

 #if defined(_WIN32)
     mbedtls_printf( "  Press Enter to exit this program.\n" );
     fflush( stdout ); getchar();
 #endif

     return( ret );
 }

 #endif /* MBEDTLS_BIGNUM_C && MBEDTLS_CERTS_C && MBEDTLS_ENTROPY_C &&
           MBEDTLS_SSL_TLS_C && MBEDTLS_SSL_SRV_C && MBEDTLS_NET_C &&
           MBEDTLS_RSA_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_THREADING_C &&
           MBEDTLS_THREADING_PTHREAD && MBEDTLS_PEM_PARSE_C */
	/*
	* SSL server demonstration program using pthread for handling multiple
	* clients.
	*
	* 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_fprintf fprintf
	#define mbedtls_printf printf
	#define mbedtls_snprintf snprintf
	#endif

	#if !defined(MBEDTLS_BIGNUM_C) \|\| !defined(MBEDTLS_CERTS_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_FS_IO) \|\| \
	!defined(MBEDTLS_THREADING_C) \|\| !defined(MBEDTLS_THREADING_PTHREAD) \|\| \
	!defined(MBEDTLS_PEM_PARSE_C)
	int main( void )
	{
	mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_CERTS_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_THREADING_C and/or MBEDTLS_THREADING_PTHREAD "
	"and/or MBEDTLS_PEM_PARSE_C not defined.\n");
	return( 0 );
	}
	#else

	#include <stdlib.h>
	#include <string.h>

	#if defined(_WIN32)
	#include <windows.h>
	#endif

	#include "mbedtls/entropy.h"
	#include "mbedtls/ctr_drbg.h"
	#include "mbedtls/certs.h"
	#include "mbedtls/x509.h"
	#include "mbedtls/ssl.h"
	#include "mbedtls/net.h"
	#include "mbedtls/error.h"

	#if defined(MBEDTLS_SSL_CACHE_C)
	#include "mbedtls/ssl_cache.h"
	#endif

	#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
	#include "mbedtls/memory_buffer_alloc.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

	#define MAX_NUM_THREADS 5

	mbedtls_threading_mutex_t debug_mutex;

	static void my_mutexed_debug( void *ctx, int level,
	const char *file, int line,
	const char *str )
	{
	long int thread_id = (long int) pthread_self();

	mbedtls_mutex_lock( &debug_mutex );

	((void) level);
	mbedtls_fprintf( (FILE *) ctx, "%s:%04d: [ #%ld ] %s",
	file, line, thread_id, str );
	fflush( (FILE *) ctx );

	mbedtls_mutex_unlock( &debug_mutex );
	}

	typedef struct {
	mbedtls_net_context client_fd;
	int thread_complete;
	const mbedtls_ssl_config *config;
	} thread_info_t;

	typedef struct {
	int active;
	thread_info_t data;
	pthread_t thread;
	} pthread_info_t;

	static thread_info_t base_info;
	static pthread_info_t threads[MAX_NUM_THREADS];

	static void handle_ssl_connection( void data )
	{
	int ret, len;
	thread_info_t thread_info = (thread_info_t ) data;
	mbedtls_net_context *client_fd = &thread_info->client_fd;
	long int thread_id = (long int) pthread_self();
	unsigned char buf[1024];
	mbedtls_ssl_context ssl;

	/* Make sure memory references are valid */
	mbedtls_ssl_init( &ssl );

	mbedtls_printf( " [ #%ld ] Setting up SSL/TLS data\n", thread_id );

	/*
	* 4. Get the SSL context ready
	*/
	if( ( ret = mbedtls_ssl_setup( &ssl, thread_info->config ) ) != 0 )
	{
	mbedtls_printf( " [ #%ld ] failed: mbedtls_ssl_setup returned -0x%04x\n",
	thread_id, -ret );
	goto thread_exit;
	}

	mbedtls_ssl_set_bio( &ssl, client_fd, mbedtls_net_send, mbedtls_net_recv, NULL );

	/*
	* 5. Handshake
	*/
	mbedtls_printf( " [ #%ld ] Performing the SSL/TLS handshake\n", thread_id );

	while( ( ret = mbedtls_ssl_handshake( &ssl ) ) != 0 )
	{
	if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
	{
	mbedtls_printf( " [ #%ld ] failed: mbedtls_ssl_handshake returned -0x%04x\n",
	thread_id, -ret );
	goto thread_exit;
	}
	}

	mbedtls_printf( " [ #%ld ] ok\n", thread_id );

	/*
	* 6. Read the HTTP Request
	*/
	mbedtls_printf( " [ #%ld ] < Read from client\n", thread_id );

	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( " [ #%ld ] connection was closed gracefully\n",
	thread_id );
	goto thread_exit;

	case MBEDTLS_ERR_NET_CONN_RESET:
	mbedtls_printf( " [ #%ld ] connection was reset by peer\n",
	thread_id );
	goto thread_exit;

	default:
	mbedtls_printf( " [ #%ld ] mbedtls_ssl_read returned -0x%04x\n",
	thread_id, -ret );
	goto thread_exit;
	}
	}

	len = ret;
	mbedtls_printf( " [ #%ld ] %d bytes read\n=====\n%s\n=====\n",
	thread_id, len, (char *) buf );

	if( ret > 0 )
	break;
	}
	while( 1 );

	/*
	* 7. Write the 200 Response
	*/
	mbedtls_printf( " [ #%ld ] > Write to client:\n", thread_id );

	len = sprintf( (char *) buf, HTTP_RESPONSE,
	mbedtls_ssl_get_ciphersuite( &ssl ) );

	while( ( ret = mbedtls_ssl_write( &ssl, buf, len ) ) <= 0 )
	{
	if( ret == MBEDTLS_ERR_NET_CONN_RESET )
	{
	mbedtls_printf( " [ #%ld ] failed: peer closed the connection\n",
	thread_id );
	goto thread_exit;
	}

	if( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE )
	{
	mbedtls_printf( " [ #%ld ] failed: mbedtls_ssl_write returned -0x%04x\n",
	thread_id, ret );
	goto thread_exit;
	}
	}

	len = ret;
	mbedtls_printf( " [ #%ld ] %d bytes written\n=====\n%s\n=====\n",
	thread_id, len, (char *) buf );

	mbedtls_printf( " [ #%ld ] . Closing the connection...", thread_id );

	while( ( ret = mbedtls_ssl_close_notify( &ssl ) ) < 0 )
	{
	if( ret != MBEDTLS_ERR_SSL_WANT_READ &&
	ret != MBEDTLS_ERR_SSL_WANT_WRITE )
	{
	mbedtls_printf( " [ #%ld ] failed: mbedtls_ssl_close_notify returned -0x%04x\n",
	thread_id, ret );
	goto thread_exit;
	}
	}

	mbedtls_printf( " ok\n" );

	ret = 0;

	thread_exit:

	#ifdef MBEDTLS_ERROR_C
	if( ret != 0 )
	{
	char error_buf[100];
	mbedtls_strerror( ret, error_buf, 100 );
	mbedtls_printf(" [ #%ld ] Last error was: -0x%04x - %s\n\n",
	thread_id, -ret, error_buf );
	}
	#endif

	mbedtls_net_free( client_fd );
	mbedtls_ssl_free( &ssl );

	thread_info->thread_complete = 1;

	return( NULL );
	}

	static int thread_create( mbedtls_net_context *client_fd )
	{
	int ret, i;

	/*
	* Find in-active or finished thread slot
	*/
	for( i = 0; i < MAX_NUM_THREADS; i++ )
	{
	if( threads[i].active == 0 )
	break;

	if( threads[i].data.thread_complete == 1 )
	{
	mbedtls_printf( " [ main ] Cleaning up thread %d\n", i );
	pthread_join(threads[i].thread, NULL );
	memset( &threads[i], 0, sizeof(pthread_info_t) );
	break;
	}
	}

	if( i == MAX_NUM_THREADS )
	return( -1 );

	/*
	* Fill thread-info for thread
	*/
	memcpy( &threads[i].data, &base_info, sizeof(base_info) );
	threads[i].active = 1;
	memcpy( &threads[i].data.client_fd, client_fd, sizeof( mbedtls_net_context ) );

	if( ( ret = pthread_create( &threads[i].thread, NULL, handle_ssl_connection,
	&threads[i].data ) ) != 0 )
	{
	return( ret );
	}

	return( 0 );
	}

	int main( void )
	{
	int ret;
	mbedtls_net_context listen_fd, client_fd;
	const char pers[] = "ssl_pthread_server";

	mbedtls_entropy_context entropy;
	mbedtls_ctr_drbg_context ctr_drbg;
	mbedtls_ssl_config conf;
	mbedtls_x509_crt srvcert;
	mbedtls_x509_crt cachain;
	mbedtls_pk_context pkey;
	#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
	unsigned char alloc_buf[100000];
	#endif
	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_cache_context cache;
	#endif

	#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
	mbedtls_memory_buffer_alloc_init( alloc_buf, sizeof(alloc_buf) );
	#endif

	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_cache_init( &cache );
	#endif

	mbedtls_x509_crt_init( &srvcert );
	mbedtls_x509_crt_init( &cachain );

	mbedtls_ssl_config_init( &conf );
	mbedtls_ctr_drbg_init( &ctr_drbg );
	memset( threads, 0, sizeof(threads) );
	mbedtls_net_init( &listen_fd );
	mbedtls_net_init( &client_fd );

	mbedtls_mutex_init( &debug_mutex );

	base_info.config = &conf;

	/*
	* We use only a single entropy source that is used in all the threads.
	*/
	mbedtls_entropy_init( &entropy );

	/*
	* 1. Load the certificates and private RSA key
	*/
	mbedtls_printf( "\n . 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\n ! mbedtls_x509_crt_parse returned %d\n\n", ret );
	goto exit;
	}

	ret = mbedtls_x509_crt_parse( &cachain, (const unsigned char *) mbedtls_test_cas_pem,
	mbedtls_test_cas_pem_len );
	if( ret != 0 )
	{
	mbedtls_printf( " failed\n ! mbedtls_x509_crt_parse returned %d\n\n", ret );
	goto exit;
	}

	mbedtls_pk_init( &pkey );
	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\n ! mbedtls_pk_parse_key returned %d\n\n", ret );
	goto exit;
	}

	mbedtls_printf( " ok\n" );

	/*
	* 1b. Seed the random number generator
	*/
	mbedtls_printf( " . Seeding the random number generator..." );

	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 -0x%04x\n",
	-ret );
	goto exit;
	}

	mbedtls_printf( " ok\n" );

	/*
	* 1c. Prepare SSL configuration
	*/
	mbedtls_printf( " . Setting up the SSL data...." );

	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 -0x%04x\n",
	-ret );
	goto exit;
	}

	mbedtls_ssl_conf_rng( &conf, mbedtls_ctr_drbg_random, &ctr_drbg );
	mbedtls_ssl_conf_dbg( &conf, my_mutexed_debug, stdout );

	/* mbedtls_ssl_cache_get() and mbedtls_ssl_cache_set() are thread-safe if
	* MBEDTLS_THREADING_C is set.
	*/
	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_conf_session_cache( &conf, &cache,
	mbedtls_ssl_cache_get,
	mbedtls_ssl_cache_set );
	#endif

	mbedtls_ssl_conf_ca_chain( &conf, &cachain, NULL );
	if( ( ret = mbedtls_ssl_conf_own_cert( &conf, &srvcert, &pkey ) ) != 0 )
	{
	mbedtls_printf( " failed\n ! 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\n ! mbedtls_net_bind returned %d\n\n", ret );
	goto exit;
	}

	mbedtls_printf( " ok\n" );

	reset:
	#ifdef MBEDTLS_ERROR_C
	if( ret != 0 )
	{
	char error_buf[100];
	mbedtls_strerror( ret, error_buf, 100 );
	mbedtls_printf( " [ main ] Last error was: -0x%04x - %s\n", -ret, error_buf );
	}
	#endif

	/*
	* 3. Wait until a client connects
	*/
	mbedtls_printf( " [ main ] Waiting for a remote connection\n" );

	if( ( ret = mbedtls_net_accept( &listen_fd, &client_fd,
	NULL, 0, NULL ) ) != 0 )
	{
	mbedtls_printf( " [ main ] failed: mbedtls_net_accept returned -0x%04x\n", ret );
	goto exit;
	}

	mbedtls_printf( " [ main ] ok\n" );
	mbedtls_printf( " [ main ] Creating a new thread\n" );

	if( ( ret = thread_create( &client_fd ) ) != 0 )
	{
	mbedtls_printf( " [ main ] failed: thread_create returned %d\n", ret );
	mbedtls_net_free( &client_fd );
	goto reset;
	}

	ret = 0;
	goto reset;

	exit:
	mbedtls_x509_crt_free( &srvcert );
	mbedtls_pk_free( &pkey );
	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_cache_free( &cache );
	#endif
	mbedtls_ctr_drbg_free( &ctr_drbg );
	mbedtls_entropy_free( &entropy );
	mbedtls_ssl_config_free( &conf );

	mbedtls_net_free( &listen_fd );

	mbedtls_mutex_free( &debug_mutex );

	#if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
	mbedtls_memory_buffer_alloc_free();
	#endif

	#if defined(_WIN32)
	mbedtls_printf( " Press Enter to exit this program.\n" );
	fflush( stdout ); getchar();
	#endif

	return( ret );
	}

	#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_CERTS_C && MBEDTLS_ENTROPY_C &&
	MBEDTLS_SSL_TLS_C && MBEDTLS_SSL_SRV_C && MBEDTLS_NET_C &&
	MBEDTLS_RSA_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_THREADING_C &&
	MBEDTLS_THREADING_PTHREAD && MBEDTLS_PEM_PARSE_C */