programs/x509/cert_req.c - security/mbedtls - Rivoreo Source Code Repositories

 /*
  *  Certificate request generation
  *
  *  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>
 #include <stdlib.h>
 #define mbedtls_printf          printf
 #define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
 #define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
 #endif /* MBEDTLS_PLATFORM_C */

 #if !defined(MBEDTLS_X509_CSR_WRITE_C) || !defined(MBEDTLS_FS_IO) ||  \
     !defined(MBEDTLS_PK_PARSE_C) || !defined(MBEDTLS_SHA256_C) || \
     !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
     !defined(MBEDTLS_PEM_WRITE_C)
 int main( void )
 {
     mbedtls_printf( "MBEDTLS_X509_CSR_WRITE_C and/or MBEDTLS_FS_IO and/or "
             "MBEDTLS_PK_PARSE_C and/or MBEDTLS_SHA256_C and/or "
             "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
             "not defined.\n");
     return( 0 );
 }
 #else

 #include "mbedtls/x509_csr.h"
 #include "mbedtls/entropy.h"
 #include "mbedtls/ctr_drbg.h"
 #include "mbedtls/error.h"

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

 #define DFL_FILENAME            "keyfile.key"
 #define DFL_DEBUG_LEVEL         0
 #define DFL_OUTPUT_FILENAME     "cert.req"
 #define DFL_SUBJECT_NAME        "CN=Cert,O=mbed TLS,C=UK"
 #define DFL_KEY_USAGE           0
 #define DFL_NS_CERT_TYPE        0

 #define USAGE \
     "\n usage: cert_req param=<>...\n"                  \
     "\n acceptable parameters:\n"                       \
     "    filename=%%s         default: keyfile.key\n"   \
     "    debug_level=%%d      default: 0 (disabled)\n"  \
     "    output_file=%%s      default: cert.req\n"      \
     "    subject_name=%%s     default: CN=Cert,O=mbed TLS,C=UK\n"   \
     "    key_usage=%%s        default: (empty)\n"       \
     "                        Comma-separated-list of values:\n"     \
     "                          digital_signature\n"     \
     "                          non_repudiation\n"       \
     "                          key_encipherment\n"      \
     "                          data_encipherment\n"     \
     "                          key_agreement\n"         \
     "                          key_cert_sign\n"  \
     "                          crl_sign\n"              \
     "    ns_cert_type=%%s     default: (empty)\n"       \
     "                        Comma-separated-list of values:\n"     \
     "                          ssl_client\n"            \
     "                          ssl_server\n"            \
     "                          email\n"                 \
     "                          object_signing\n"        \
     "                          ssl_ca\n"                \
     "                          email_ca\n"              \
     "                          object_signing_ca\n"     \
     "\n"

 /*
  * global options
  */
 struct options
 {
     const char *filename;       /* filename of the key file             */
     int debug_level;            /* level of debugging                   */
     const char *output_file;    /* where to store the constructed key file  */
     const char *subject_name;   /* subject name for certificate request */
     unsigned char key_usage;    /* key usage flags                      */
     unsigned char ns_cert_type; /* NS cert type                         */
 } opt;

 int write_certificate_request( mbedtls_x509write_csr *req, const char *output_file,
                                int (*f_rng)(void *, unsigned char *, size_t),
                                void *p_rng )
 {
     int ret;
     FILE *f;
     unsigned char output_buf[4096];
     size_t len = 0;

     memset( output_buf, 0, 4096 );
     if( ( ret = mbedtls_x509write_csr_pem( req, output_buf, 4096, f_rng, p_rng ) ) < 0 )
         return( ret );

     len = strlen( (char *) output_buf );

     if( ( f = fopen( output_file, "w" ) ) == NULL )
         return( -1 );

     if( fwrite( output_buf, 1, len, f ) != len )
     {
         fclose( f );
         return( -1 );
     }

     fclose( f );

     return( 0 );
 }

 int main( int argc, char *argv[] )
 {
     int ret = 1;
     int exit_code = MBEDTLS_EXIT_FAILURE;
     mbedtls_pk_context key;
     char buf[1024];
     int i;
     char *p, *q, *r;
     mbedtls_x509write_csr req;
     mbedtls_entropy_context entropy;
     mbedtls_ctr_drbg_context ctr_drbg;
     const char *pers = "csr example app";

     /*
      * Set to sane values
      */
     mbedtls_x509write_csr_init( &req );
     mbedtls_x509write_csr_set_md_alg( &req, MBEDTLS_MD_SHA256 );
     mbedtls_pk_init( &key );
     mbedtls_ctr_drbg_init( &ctr_drbg );
     memset( buf, 0, sizeof( buf ) );

     if( argc == 0 )
     {
     usage:
         mbedtls_printf( USAGE );
         goto exit;
     }

     opt.filename            = DFL_FILENAME;
     opt.debug_level         = DFL_DEBUG_LEVEL;
     opt.output_file         = DFL_OUTPUT_FILENAME;
     opt.subject_name        = DFL_SUBJECT_NAME;
     opt.key_usage           = DFL_KEY_USAGE;
     opt.ns_cert_type        = DFL_NS_CERT_TYPE;

     for( i = 1; i < argc; i++ )
     {

         p = argv[i];
         if( ( q = strchr( p, '=' ) ) == NULL )
             goto usage;
         *q++ = '\0';

         if( strcmp( p, "filename" ) == 0 )
             opt.filename = q;
         else if( strcmp( p, "output_file" ) == 0 )
             opt.output_file = q;
         else if( strcmp( p, "debug_level" ) == 0 )
         {
             opt.debug_level = atoi( q );
             if( opt.debug_level < 0 || opt.debug_level > 65535 )
                 goto usage;
         }
         else if( strcmp( p, "subject_name" ) == 0 )
         {
             opt.subject_name = q;
         }
         else if( strcmp( p, "key_usage" ) == 0 )
         {
             while( q != NULL )
             {
                 if( ( r = strchr( q, ',' ) ) != NULL )
                     *r++ = '\0';

                 if( strcmp( q, "digital_signature" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_DIGITAL_SIGNATURE;
                 else if( strcmp( q, "non_repudiation" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_NON_REPUDIATION;
                 else if( strcmp( q, "key_encipherment" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_KEY_ENCIPHERMENT;
                 else if( strcmp( q, "data_encipherment" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_DATA_ENCIPHERMENT;
                 else if( strcmp( q, "key_agreement" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_KEY_AGREEMENT;
                 else if( strcmp( q, "key_cert_sign" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_KEY_CERT_SIGN;
                 else if( strcmp( q, "crl_sign" ) == 0 )
                     opt.key_usage |= MBEDTLS_X509_KU_CRL_SIGN;
                 else
                     goto usage;

                 q = r;
             }
         }
         else if( strcmp( p, "ns_cert_type" ) == 0 )
         {
             while( q != NULL )
             {
                 if( ( r = strchr( q, ',' ) ) != NULL )
                     *r++ = '\0';

                 if( strcmp( q, "ssl_client" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT;
                 else if( strcmp( q, "ssl_server" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER;
                 else if( strcmp( q, "email" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_EMAIL;
                 else if( strcmp( q, "object_signing" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING;
                 else if( strcmp( q, "ssl_ca" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_SSL_CA;
                 else if( strcmp( q, "email_ca" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA;
                 else if( strcmp( q, "object_signing_ca" ) == 0 )
                     opt.ns_cert_type |= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA;
                 else
                     goto usage;

                 q = r;
             }
         }
         else
             goto usage;
     }

     if( opt.key_usage )
         mbedtls_x509write_csr_set_key_usage( &req, opt.key_usage );

     if( opt.ns_cert_type )
         mbedtls_x509write_csr_set_ns_cert_type( &req, opt.ns_cert_type );

     /*
      * 0. Seed the PRNG
      */
     mbedtls_printf( "  . 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", ret );
         goto exit;
     }

     mbedtls_printf( " ok\n" );

     /*
      * 1.0. Check the subject name for validity
      */
     mbedtls_printf( "  . Checking subject name..." );
     fflush( stdout );

     if( ( ret = mbedtls_x509write_csr_set_subject_name( &req, opt.subject_name ) ) != 0 )
     {
         mbedtls_printf( " failed\n  !  mbedtls_x509write_csr_set_subject_name returned %d", ret );
         goto exit;
     }

     mbedtls_printf( " ok\n" );

     /*
      * 1.1. Load the key
      */
     mbedtls_printf( "  . Loading the private key ..." );
     fflush( stdout );

     ret = mbedtls_pk_parse_keyfile( &key, opt.filename, NULL );

     if( ret != 0 )
     {
         mbedtls_printf( " failed\n  !  mbedtls_pk_parse_keyfile returned %d", ret );
         goto exit;
     }

     mbedtls_x509write_csr_set_key( &req, &key );

     mbedtls_printf( " ok\n" );

     /*
      * 1.2. Writing the request
      */
     mbedtls_printf( "  . Writing the certificate request ..." );
     fflush( stdout );

     if( ( ret = write_certificate_request( &req, opt.output_file,
                                            mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
     {
         mbedtls_printf( " failed\n  !  write_certifcate_request %d", ret );
         goto exit;
     }

     mbedtls_printf( " ok\n" );

     exit_code = MBEDTLS_EXIT_SUCCESS;

 exit:

     if( exit_code != MBEDTLS_EXIT_SUCCESS )
     {
 #ifdef MBEDTLS_ERROR_C
         mbedtls_strerror( ret, buf, sizeof( buf ) );
         mbedtls_printf( " - %s\n", buf );
 #else
         mbedtls_printf("\n");
 #endif
     }

     mbedtls_x509write_csr_free( &req );
     mbedtls_pk_free( &key );
     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

     return( exit_code );
 }
 #endif /* MBEDTLS_X509_CSR_WRITE_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
           MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_PEM_WRITE_C */
	/*
	* Certificate request generation
	*
	* 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>
	#include <stdlib.h>
	#define mbedtls_printf printf
	#define MBEDTLS_EXIT_SUCCESS EXIT_SUCCESS
	#define MBEDTLS_EXIT_FAILURE EXIT_FAILURE
	#endif /* MBEDTLS_PLATFORM_C */

	#if !defined(MBEDTLS_X509_CSR_WRITE_C) \|\| !defined(MBEDTLS_FS_IO) \|\| \
	!defined(MBEDTLS_PK_PARSE_C) \|\| !defined(MBEDTLS_SHA256_C) \|\| \
	!defined(MBEDTLS_ENTROPY_C) \|\| !defined(MBEDTLS_CTR_DRBG_C) \|\| \
	!defined(MBEDTLS_PEM_WRITE_C)
	int main( void )
	{
	mbedtls_printf( "MBEDTLS_X509_CSR_WRITE_C and/or MBEDTLS_FS_IO and/or "
	"MBEDTLS_PK_PARSE_C and/or MBEDTLS_SHA256_C and/or "
	"MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C "
	"not defined.\n");
	return( 0 );
	}
	#else

	#include "mbedtls/x509_csr.h"
	#include "mbedtls/entropy.h"
	#include "mbedtls/ctr_drbg.h"
	#include "mbedtls/error.h"

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

	#define DFL_FILENAME "keyfile.key"
	#define DFL_DEBUG_LEVEL 0
	#define DFL_OUTPUT_FILENAME "cert.req"
	#define DFL_SUBJECT_NAME "CN=Cert,O=mbed TLS,C=UK"
	#define DFL_KEY_USAGE 0
	#define DFL_NS_CERT_TYPE 0

	#define USAGE \
	"\n usage: cert_req param=<>...\n" \
	"\n acceptable parameters:\n" \
	" filename=%%s default: keyfile.key\n" \
	" debug_level=%%d default: 0 (disabled)\n" \
	" output_file=%%s default: cert.req\n" \
	" subject_name=%%s default: CN=Cert,O=mbed TLS,C=UK\n" \
	" key_usage=%%s default: (empty)\n" \
	" Comma-separated-list of values:\n" \
	" digital_signature\n" \
	" non_repudiation\n" \
	" key_encipherment\n" \
	" data_encipherment\n" \
	" key_agreement\n" \
	" key_cert_sign\n" \
	" crl_sign\n" \
	" ns_cert_type=%%s default: (empty)\n" \
	" Comma-separated-list of values:\n" \
	" ssl_client\n" \
	" ssl_server\n" \
	" email\n" \
	" object_signing\n" \
	" ssl_ca\n" \
	" email_ca\n" \
	" object_signing_ca\n" \
	"\n"

	/*
	* global options
	*/
	struct options
	{
	const char filename; / filename of the key file */
	int debug_level; /* level of debugging */
	const char output_file; / where to store the constructed key file */
	const char subject_name; / subject name for certificate request */
	unsigned char key_usage; /* key usage flags */
	unsigned char ns_cert_type; /* NS cert type */
	} opt;

	int write_certificate_request( mbedtls_x509write_csr req, const char output_file,
	int (f_rng)(void , unsigned char *, size_t),
	void *p_rng )
	{
	int ret;
	FILE *f;
	unsigned char output_buf[4096];
	size_t len = 0;

	memset( output_buf, 0, 4096 );
	if( ( ret = mbedtls_x509write_csr_pem( req, output_buf, 4096, f_rng, p_rng ) ) < 0 )
	return( ret );

	len = strlen( (char *) output_buf );

	if( ( f = fopen( output_file, "w" ) ) == NULL )
	return( -1 );

	if( fwrite( output_buf, 1, len, f ) != len )
	{
	fclose( f );
	return( -1 );
	}

	fclose( f );

	return( 0 );
	}

	int main( int argc, char *argv[] )
	{
	int ret = 1;
	int exit_code = MBEDTLS_EXIT_FAILURE;
	mbedtls_pk_context key;
	char buf[1024];
	int i;
	char p, q, *r;
	mbedtls_x509write_csr req;
	mbedtls_entropy_context entropy;
	mbedtls_ctr_drbg_context ctr_drbg;
	const char *pers = "csr example app";

	/*
	* Set to sane values
	*/
	mbedtls_x509write_csr_init( &req );
	mbedtls_x509write_csr_set_md_alg( &req, MBEDTLS_MD_SHA256 );
	mbedtls_pk_init( &key );
	mbedtls_ctr_drbg_init( &ctr_drbg );
	memset( buf, 0, sizeof( buf ) );

	if( argc == 0 )
	{
	usage:
	mbedtls_printf( USAGE );
	goto exit;
	}

	opt.filename = DFL_FILENAME;
	opt.debug_level = DFL_DEBUG_LEVEL;
	opt.output_file = DFL_OUTPUT_FILENAME;
	opt.subject_name = DFL_SUBJECT_NAME;
	opt.key_usage = DFL_KEY_USAGE;
	opt.ns_cert_type = DFL_NS_CERT_TYPE;

	for( i = 1; i < argc; i++ )
	{

	p = argv[i];
	if( ( q = strchr( p, '=' ) ) == NULL )
	goto usage;
	*q++ = '\0';

	if( strcmp( p, "filename" ) == 0 )
	opt.filename = q;
	else if( strcmp( p, "output_file" ) == 0 )
	opt.output_file = q;
	else if( strcmp( p, "debug_level" ) == 0 )
	{
	opt.debug_level = atoi( q );
	if( opt.debug_level < 0 \|\| opt.debug_level > 65535 )
	goto usage;
	}
	else if( strcmp( p, "subject_name" ) == 0 )
	{
	opt.subject_name = q;
	}
	else if( strcmp( p, "key_usage" ) == 0 )
	{
	while( q != NULL )
	{
	if( ( r = strchr( q, ',' ) ) != NULL )
	*r++ = '\0';

	if( strcmp( q, "digital_signature" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_DIGITAL_SIGNATURE;
	else if( strcmp( q, "non_repudiation" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_NON_REPUDIATION;
	else if( strcmp( q, "key_encipherment" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_KEY_ENCIPHERMENT;
	else if( strcmp( q, "data_encipherment" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_DATA_ENCIPHERMENT;
	else if( strcmp( q, "key_agreement" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_KEY_AGREEMENT;
	else if( strcmp( q, "key_cert_sign" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_KEY_CERT_SIGN;
	else if( strcmp( q, "crl_sign" ) == 0 )
	opt.key_usage \|= MBEDTLS_X509_KU_CRL_SIGN;
	else
	goto usage;

	q = r;
	}
	}
	else if( strcmp( p, "ns_cert_type" ) == 0 )
	{
	while( q != NULL )
	{
	if( ( r = strchr( q, ',' ) ) != NULL )
	*r++ = '\0';

	if( strcmp( q, "ssl_client" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_SSL_CLIENT;
	else if( strcmp( q, "ssl_server" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER;
	else if( strcmp( q, "email" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_EMAIL;
	else if( strcmp( q, "object_signing" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING;
	else if( strcmp( q, "ssl_ca" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_SSL_CA;
	else if( strcmp( q, "email_ca" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_EMAIL_CA;
	else if( strcmp( q, "object_signing_ca" ) == 0 )
	opt.ns_cert_type \|= MBEDTLS_X509_NS_CERT_TYPE_OBJECT_SIGNING_CA;
	else
	goto usage;

	q = r;
	}
	}
	else
	goto usage;
	}

	if( opt.key_usage )
	mbedtls_x509write_csr_set_key_usage( &req, opt.key_usage );

	if( opt.ns_cert_type )
	mbedtls_x509write_csr_set_ns_cert_type( &req, opt.ns_cert_type );

	/*
	* 0. Seed the PRNG
	*/
	mbedtls_printf( " . 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", ret );
	goto exit;
	}

	mbedtls_printf( " ok\n" );

	/*
	* 1.0. Check the subject name for validity
	*/
	mbedtls_printf( " . Checking subject name..." );
	fflush( stdout );

	if( ( ret = mbedtls_x509write_csr_set_subject_name( &req, opt.subject_name ) ) != 0 )
	{
	mbedtls_printf( " failed\n ! mbedtls_x509write_csr_set_subject_name returned %d", ret );
	goto exit;
	}

	mbedtls_printf( " ok\n" );

	/*
	* 1.1. Load the key
	*/
	mbedtls_printf( " . Loading the private key ..." );
	fflush( stdout );

	ret = mbedtls_pk_parse_keyfile( &key, opt.filename, NULL );

	if( ret != 0 )
	{
	mbedtls_printf( " failed\n ! mbedtls_pk_parse_keyfile returned %d", ret );
	goto exit;
	}

	mbedtls_x509write_csr_set_key( &req, &key );

	mbedtls_printf( " ok\n" );

	/*
	* 1.2. Writing the request
	*/
	mbedtls_printf( " . Writing the certificate request ..." );
	fflush( stdout );

	if( ( ret = write_certificate_request( &req, opt.output_file,
	mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
	{
	mbedtls_printf( " failed\n ! write_certifcate_request %d", ret );
	goto exit;
	}

	mbedtls_printf( " ok\n" );

	exit_code = MBEDTLS_EXIT_SUCCESS;

	exit:

	if( exit_code != MBEDTLS_EXIT_SUCCESS )
	{
	#ifdef MBEDTLS_ERROR_C
	mbedtls_strerror( ret, buf, sizeof( buf ) );
	mbedtls_printf( " - %s\n", buf );
	#else
	mbedtls_printf("\n");
	#endif
	}

	mbedtls_x509write_csr_free( &req );
	mbedtls_pk_free( &key );
	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

	return( exit_code );
	}
	#endif /* MBEDTLS_X509_CSR_WRITE_C && MBEDTLS_PK_PARSE_C && MBEDTLS_FS_IO &&
	MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C && MBEDTLS_PEM_WRITE_C */