programs/ssl/ssl_server.c - mirror/mbed-tls.git - TrustedFirmware Git Browser

 /*
  *  SSL server demonstration program
  *
  *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
  */

 #include "mbedtls/build_info.h"

 #include "mbedtls/platform.h"

 #if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_PEM_PARSE_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)
 int main(void)
 {
     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_PEM_PARSE_C not defined.\n");
     mbedtls_exit(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/x509.h"
 #include "mbedtls/ssl.h"
 #include "mbedtls/net_sockets.h"
 #include "mbedtls/error.h"
 #include "mbedtls/debug.h"
 #include "test/certs.h"

 #if defined(MBEDTLS_SSL_CACHE_C)
 #include "mbedtls/ssl_cache.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, len;
     mbedtls_net_context listen_fd, client_fd;
     unsigned char buf[1024];
     const char *pers = "ssl_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;
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_context cache;
 #endif

     mbedtls_net_init(&listen_fd);
     mbedtls_net_init(&client_fd);
     mbedtls_ssl_init(&ssl);
     mbedtls_ssl_config_init(&conf);
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_init(&cache);
 #endif
     mbedtls_x509_crt_init(&srvcert);
     mbedtls_pk_init(&pkey);
     mbedtls_entropy_init(&entropy);
     mbedtls_ctr_drbg_init(&ctr_drbg);

 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     psa_status_t status = psa_crypto_init();
     if (status != PSA_SUCCESS) {
         mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
                         (int) status);
         ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
         goto exit;
     }
 #endif /* MBEDTLS_USE_PSA_CRYPTO */

 #if defined(MBEDTLS_DEBUG_C)
     mbedtls_debug_set_threshold(DEBUG_LEVEL);
 #endif

     /*
      * 1. Seed the RNG
      */
     mbedtls_printf("  . Seeding the random number 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\n  ! mbedtls_ctr_drbg_seed returned %d\n", ret);
         goto exit;
     }

     mbedtls_printf(" ok\n");

     /*
      * 2. 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(&srvcert, (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;
     }

     ret =  mbedtls_pk_parse_key(&pkey, (const unsigned char *) mbedtls_test_srv_key,
                                 mbedtls_test_srv_key_len, NULL, 0,
                                 mbedtls_ctr_drbg_random, &ctr_drbg);
     if (ret != 0) {
         mbedtls_printf(" failed\n  !  mbedtls_pk_parse_key returned %d\n\n", ret);
         goto exit;
     }

     mbedtls_printf(" ok\n");

     /*
      * 3. 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");

     /*
      * 4. Setup stuff
      */
     mbedtls_printf("  . Setting up the SSL data....");
     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\n  ! 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);

 #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, srvcert.next, 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;
     }

     if ((ret = mbedtls_ssl_setup(&ssl, &conf)) != 0) {
         mbedtls_printf(" failed\n  ! mbedtls_ssl_setup 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("Last error was: %d - %s\n\n", ret, error_buf);
     }
 #endif

     mbedtls_net_free(&client_fd);

     mbedtls_ssl_session_reset(&ssl);

     /*
      * 3. Wait until a client connects
      */
     mbedtls_printf("  . Waiting for a remote connection ...");
     fflush(stdout);

     if ((ret = mbedtls_net_accept(&listen_fd, &client_fd,
                                   NULL, 0, NULL)) != 0) {
         mbedtls_printf(" failed\n  ! mbedtls_net_accept returned %d\n\n", ret);
         goto exit;
     }

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

     mbedtls_printf(" ok\n");

     /*
      * 5. 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 %d\n\n", ret);
             goto reset;
         }
     }

     mbedtls_printf(" ok\n");

     /*
      * 6. Read the HTTP Request
      */
     mbedtls_printf("  < Read from client:");
     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(" connection was closed gracefully\n");
                     break;

                 case MBEDTLS_ERR_NET_CONN_RESET:
                     mbedtls_printf(" connection was reset by peer\n");
                     break;

                 default:
                     mbedtls_printf(" mbedtls_ssl_read returned -0x%x\n", (unsigned int) -ret);
                     break;
             }

             break;
         }

         len = ret;
         mbedtls_printf(" %d bytes read\n\n%s", len, (char *) buf);

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

     /*
      * 7. Write the 200 Response
      */
     mbedtls_printf("  > Write to client:");
     fflush(stdout);

     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(" failed\n  ! peer closed the connection\n\n");
             goto reset;
         }

         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\n", len, (char *) buf);

     mbedtls_printf("  . Closing the connection...");

     while ((ret = mbedtls_ssl_close_notify(&ssl)) < 0) {
         if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
             ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
             mbedtls_printf(" failed\n  ! mbedtls_ssl_close_notify returned %d\n\n", ret);
             goto reset;
         }
     }

     mbedtls_printf(" ok\n");

     ret = 0;
     goto reset;

 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(&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);
 #if defined(MBEDTLS_SSL_CACHE_C)
     mbedtls_ssl_cache_free(&cache);
 #endif
     mbedtls_ctr_drbg_free(&ctr_drbg);
     mbedtls_entropy_free(&entropy);
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
     mbedtls_psa_crypto_free();
 #endif /* MBEDTLS_USE_PSA_CRYPTO */

     mbedtls_exit(ret);
 }
 #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_X509_CRT_PARSE_C
           && MBEDTLS_FS_IO && MBEDTLS_PEM_PARSE_C */
	/*
	* SSL server demonstration program
	*
	* Copyright The Mbed TLS Contributors
	* SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
	*/

	#include "mbedtls/build_info.h"

	#include "mbedtls/platform.h"

	#if !defined(MBEDTLS_BIGNUM_C) \|\| !defined(MBEDTLS_PEM_PARSE_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)
	int main(void)
	{
	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_PEM_PARSE_C not defined.\n");
	mbedtls_exit(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/x509.h"
	#include "mbedtls/ssl.h"
	#include "mbedtls/net_sockets.h"
	#include "mbedtls/error.h"
	#include "mbedtls/debug.h"
	#include "test/certs.h"

	#if defined(MBEDTLS_SSL_CACHE_C)
	#include "mbedtls/ssl_cache.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, len;
	mbedtls_net_context listen_fd, client_fd;
	unsigned char buf[1024];
	const char *pers = "ssl_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;
	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_cache_context cache;
	#endif

	mbedtls_net_init(&listen_fd);
	mbedtls_net_init(&client_fd);
	mbedtls_ssl_init(&ssl);
	mbedtls_ssl_config_init(&conf);
	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_cache_init(&cache);
	#endif
	mbedtls_x509_crt_init(&srvcert);
	mbedtls_pk_init(&pkey);
	mbedtls_entropy_init(&entropy);
	mbedtls_ctr_drbg_init(&ctr_drbg);

	#if defined(MBEDTLS_USE_PSA_CRYPTO)
	psa_status_t status = psa_crypto_init();
	if (status != PSA_SUCCESS) {
	mbedtls_fprintf(stderr, "Failed to initialize PSA Crypto implementation: %d\n",
	(int) status);
	ret = MBEDTLS_ERR_SSL_HW_ACCEL_FAILED;
	goto exit;
	}
	#endif /* MBEDTLS_USE_PSA_CRYPTO */

	#if defined(MBEDTLS_DEBUG_C)
	mbedtls_debug_set_threshold(DEBUG_LEVEL);
	#endif

	/*
	* 1. Seed the RNG
	*/
	mbedtls_printf(" . Seeding the random number 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\n ! mbedtls_ctr_drbg_seed returned %d\n", ret);
	goto exit;
	}

	mbedtls_printf(" ok\n");

	/*
	* 2. 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(&srvcert, (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;
	}

	ret = mbedtls_pk_parse_key(&pkey, (const unsigned char *) mbedtls_test_srv_key,
	mbedtls_test_srv_key_len, NULL, 0,
	mbedtls_ctr_drbg_random, &ctr_drbg);
	if (ret != 0) {
	mbedtls_printf(" failed\n ! mbedtls_pk_parse_key returned %d\n\n", ret);
	goto exit;
	}

	mbedtls_printf(" ok\n");

	/*
	* 3. 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");

	/*
	* 4. Setup stuff
	*/
	mbedtls_printf(" . Setting up the SSL data....");
	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\n ! 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);

	#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, srvcert.next, 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;
	}

	if ((ret = mbedtls_ssl_setup(&ssl, &conf)) != 0) {
	mbedtls_printf(" failed\n ! mbedtls_ssl_setup 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("Last error was: %d - %s\n\n", ret, error_buf);
	}
	#endif

	mbedtls_net_free(&client_fd);

	mbedtls_ssl_session_reset(&ssl);

	/*
	* 3. Wait until a client connects
	*/
	mbedtls_printf(" . Waiting for a remote connection ...");
	fflush(stdout);

	if ((ret = mbedtls_net_accept(&listen_fd, &client_fd,
	NULL, 0, NULL)) != 0) {
	mbedtls_printf(" failed\n ! mbedtls_net_accept returned %d\n\n", ret);
	goto exit;
	}

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

	mbedtls_printf(" ok\n");

	/*
	* 5. 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 %d\n\n", ret);
	goto reset;
	}
	}

	mbedtls_printf(" ok\n");

	/*
	* 6. Read the HTTP Request
	*/
	mbedtls_printf(" < Read from client:");
	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(" connection was closed gracefully\n");
	break;

	case MBEDTLS_ERR_NET_CONN_RESET:
	mbedtls_printf(" connection was reset by peer\n");
	break;

	default:
	mbedtls_printf(" mbedtls_ssl_read returned -0x%x\n", (unsigned int) -ret);
	break;
	}

	break;
	}

	len = ret;
	mbedtls_printf(" %d bytes read\n\n%s", len, (char *) buf);

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

	/*
	* 7. Write the 200 Response
	*/
	mbedtls_printf(" > Write to client:");
	fflush(stdout);

	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(" failed\n ! peer closed the connection\n\n");
	goto reset;
	}

	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\n", len, (char *) buf);

	mbedtls_printf(" . Closing the connection...");

	while ((ret = mbedtls_ssl_close_notify(&ssl)) < 0) {
	if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
	ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
	mbedtls_printf(" failed\n ! mbedtls_ssl_close_notify returned %d\n\n", ret);
	goto reset;
	}
	}

	mbedtls_printf(" ok\n");

	ret = 0;
	goto reset;

	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(&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);
	#if defined(MBEDTLS_SSL_CACHE_C)
	mbedtls_ssl_cache_free(&cache);
	#endif
	mbedtls_ctr_drbg_free(&ctr_drbg);
	mbedtls_entropy_free(&entropy);
	#if defined(MBEDTLS_USE_PSA_CRYPTO)
	mbedtls_psa_crypto_free();
	#endif /* MBEDTLS_USE_PSA_CRYPTO */

	mbedtls_exit(ret);
	}
	#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_X509_CRT_PARSE_C
	&& MBEDTLS_FS_IO && MBEDTLS_PEM_PARSE_C */