diff --git a/programs/x509/CMakeLists.txt b/programs/x509/CMakeLists.txt
new file mode 100644
index 0000000..39b8b5b
--- /dev/null
+++ b/programs/x509/CMakeLists.txt
@@ -0,0 +1,30 @@
+set(libs
+    mbedtls
+)
+
+if(USE_PKCS11_HELPER_LIBRARY)
+    set(libs ${libs} pkcs11-helper)
+endif(USE_PKCS11_HELPER_LIBRARY)
+
+if(ENABLE_ZLIB_SUPPORT)
+    set(libs ${libs} ${ZLIB_LIBRARIES})
+endif(ENABLE_ZLIB_SUPPORT)
+
+add_executable(cert_app cert_app.c)
+target_link_libraries(cert_app ${libs})
+
+add_executable(crl_app crl_app.c)
+target_link_libraries(crl_app ${libs})
+
+add_executable(req_app req_app.c)
+target_link_libraries(req_app ${libs})
+
+add_executable(cert_req cert_req.c)
+target_link_libraries(cert_req ${libs})
+
+add_executable(cert_write cert_write.c)
+target_link_libraries(cert_write ${libs})
+
+install(TARGETS cert_app crl_app req_app cert_req cert_write
+        DESTINATION "bin"
+        PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)
diff --git a/programs/x509/cert_app.c b/programs/x509/cert_app.c
new file mode 100644
index 0000000..38fbd51
--- /dev/null
+++ b/programs/x509/cert_app.c
@@ -0,0 +1,515 @@
+/*
+ *  Certificate reading application
+ *
+ *  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_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_X509_CRT_PARSE_C) || !defined(MBEDTLS_FS_IO) ||  \
+    !defined(MBEDTLS_CTR_DRBG_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_X509_CRT_PARSE_C and/or MBEDTLS_FS_IO and/or "
+           "MBEDTLS_CTR_DRBG_C not defined.\n");
+    return( 0 );
+}
+#else
+
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/net_sockets.h"
+#include "mbedtls/ssl.h"
+#include "mbedtls/x509.h"
+#include "mbedtls/debug.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define MODE_NONE               0
+#define MODE_FILE               1
+#define MODE_SSL                2
+
+#define DFL_MODE                MODE_NONE
+#define DFL_FILENAME            "cert.crt"
+#define DFL_CA_FILE             ""
+#define DFL_CRL_FILE            ""
+#define DFL_CA_PATH             ""
+#define DFL_SERVER_NAME         "localhost"
+#define DFL_SERVER_PORT         "4433"
+#define DFL_DEBUG_LEVEL         0
+#define DFL_PERMISSIVE          0
+
+#define USAGE_IO \
+    "    ca_file=%%s          The single file containing the top-level CA(s) you fully trust\n" \
+    "                        default: \"\" (none)\n" \
+    "    crl_file=%%s         The single CRL file you want to use\n" \
+    "                        default: \"\" (none)\n" \
+    "    ca_path=%%s          The path containing the top-level CA(s) you fully trust\n" \
+    "                        default: \"\" (none) (overrides ca_file)\n"
+
+#define USAGE \
+    "\n usage: cert_app param=<>...\n"                  \
+    "\n acceptable parameters:\n"                       \
+    "    mode=file|ssl       default: none\n"           \
+    "    filename=%%s         default: cert.crt\n"      \
+    USAGE_IO                                            \
+    "    server_name=%%s      default: localhost\n"     \
+    "    server_port=%%d      default: 4433\n"          \
+    "    debug_level=%%d      default: 0 (disabled)\n"  \
+    "    permissive=%%d       default: 0 (disabled)\n"  \
+    "\n"
+
+#if defined(MBEDTLS_CHECK_PARAMS)
+#define mbedtls_exit            exit
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
+/*
+ * global options
+ */
+struct options
+{
+    int mode;                   /* the mode to run the application in   */
+    const char *filename;       /* filename of the certificate file     */
+    const char *ca_file;        /* the file with the CA certificate(s)  */
+    const char *crl_file;       /* the file with the CRL to use         */
+    const char *ca_path;        /* the path with the CA certificate(s) reside */
+    const char *server_name;    /* hostname of the server (client only) */
+    const char *server_port;    /* port on which the ssl service runs   */
+    int debug_level;            /* level of debugging                   */
+    int permissive;             /* permissive parsing                   */
+} opt;
+
+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  );
+}
+
+static int my_verify( void *data, mbedtls_x509_crt *crt, int depth, uint32_t *flags )
+{
+    char buf[1024];
+    ((void) data);
+
+    mbedtls_printf( "\nVerify requested for (Depth %d):\n", depth );
+    mbedtls_x509_crt_info( buf, sizeof( buf ) - 1, "", crt );
+    mbedtls_printf( "%s", buf );
+
+    if ( ( *flags ) == 0 )
+        mbedtls_printf( "  This certificate has no flags\n" );
+    else
+    {
+        mbedtls_x509_crt_verify_info( buf, sizeof( buf ), "  ! ", *flags );
+        mbedtls_printf( "%s\n", buf );
+    }
+
+    return( 0 );
+}
+
+int main( int argc, char *argv[] )
+{
+    int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
+    mbedtls_net_context server_fd;
+    unsigned char buf[1024];
+    mbedtls_entropy_context entropy;
+    mbedtls_ctr_drbg_context ctr_drbg;
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_config conf;
+    mbedtls_x509_crt cacert;
+    mbedtls_x509_crl cacrl;
+    int i, j;
+    uint32_t flags;
+    int verify = 0;
+    char *p, *q;
+    const char *pers = "cert_app";
+
+    /*
+     * Set to sane values
+     */
+    mbedtls_net_init( &server_fd );
+    mbedtls_ctr_drbg_init( &ctr_drbg );
+    mbedtls_ssl_init( &ssl );
+    mbedtls_ssl_config_init( &conf );
+    mbedtls_x509_crt_init( &cacert );
+#if defined(MBEDTLS_X509_CRL_PARSE_C)
+    mbedtls_x509_crl_init( &cacrl );
+#else
+    /* Zeroize structure as CRL parsing is not supported and we have to pass
+       it to the verify function */
+    memset( &cacrl, 0, sizeof(mbedtls_x509_crl) );
+#endif
+
+    if( argc == 0 )
+    {
+    usage:
+        mbedtls_printf( USAGE );
+        goto exit;
+    }
+
+    opt.mode                = DFL_MODE;
+    opt.filename            = DFL_FILENAME;
+    opt.ca_file             = DFL_CA_FILE;
+    opt.crl_file            = DFL_CRL_FILE;
+    opt.ca_path             = DFL_CA_PATH;
+    opt.server_name         = DFL_SERVER_NAME;
+    opt.server_port         = DFL_SERVER_PORT;
+    opt.debug_level         = DFL_DEBUG_LEVEL;
+    opt.permissive          = DFL_PERMISSIVE;
+
+    for( i = 1; i < argc; i++ )
+    {
+        p = argv[i];
+        if( ( q = strchr( p, '=' ) ) == NULL )
+            goto usage;
+        *q++ = '\0';
+
+        for( j = 0; p + j < q; j++ )
+        {
+            if( argv[i][j] >= 'A' && argv[i][j] <= 'Z' )
+                argv[i][j] |= 0x20;
+        }
+
+        if( strcmp( p, "mode" ) == 0 )
+        {
+            if( strcmp( q, "file" ) == 0 )
+                opt.mode = MODE_FILE;
+            else if( strcmp( q, "ssl" ) == 0 )
+                opt.mode = MODE_SSL;
+            else
+                goto usage;
+        }
+        else if( strcmp( p, "filename" ) == 0 )
+            opt.filename = q;
+        else if( strcmp( p, "ca_file" ) == 0 )
+            opt.ca_file = q;
+        else if( strcmp( p, "crl_file" ) == 0 )
+            opt.crl_file = q;
+        else if( strcmp( p, "ca_path" ) == 0 )
+            opt.ca_path = q;
+        else if( strcmp( p, "server_name" ) == 0 )
+            opt.server_name = q;
+        else if( strcmp( p, "server_port" ) == 0 )
+            opt.server_port = 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, "permissive" ) == 0 )
+        {
+            opt.permissive = atoi( q );
+            if( opt.permissive < 0 || opt.permissive > 1 )
+                goto usage;
+        }
+        else
+            goto usage;
+    }
+
+    /*
+     * 1.1. Load the trusted CA
+     */
+    mbedtls_printf( "  . Loading the CA root certificate ..." );
+    fflush( stdout );
+
+    if( strlen( opt.ca_path ) )
+    {
+        if( ( ret = mbedtls_x509_crt_parse_path( &cacert, opt.ca_path ) ) < 0 )
+        {
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse_path returned -0x%x\n\n", -ret );
+            goto exit;
+        }
+
+        verify = 1;
+    }
+    else if( strlen( opt.ca_file ) )
+    {
+        if( ( ret = mbedtls_x509_crt_parse_file( &cacert, opt.ca_file ) ) < 0 )
+        {
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse_file returned -0x%x\n\n", -ret );
+            goto exit;
+        }
+
+        verify = 1;
+    }
+
+    mbedtls_printf( " ok (%d skipped)\n", ret );
+
+#if defined(MBEDTLS_X509_CRL_PARSE_C)
+    if( strlen( opt.crl_file ) )
+    {
+        if( ( ret = mbedtls_x509_crl_parse_file( &cacrl, opt.crl_file ) ) != 0 )
+        {
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crl_parse returned -0x%x\n\n", -ret );
+            goto exit;
+        }
+
+        verify = 1;
+    }
+#endif
+
+    if( opt.mode == MODE_FILE )
+    {
+        mbedtls_x509_crt crt;
+        mbedtls_x509_crt *cur = &crt;
+        mbedtls_x509_crt_init( &crt );
+
+        /*
+         * 1.1. Load the certificate(s)
+         */
+        mbedtls_printf( "\n  . Loading the certificate(s) ..." );
+        fflush( stdout );
+
+        ret = mbedtls_x509_crt_parse_file( &crt, opt.filename );
+
+        if( ret < 0 )
+        {
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse_file returned %d\n\n", ret );
+            mbedtls_x509_crt_free( &crt );
+            goto exit;
+        }
+
+        if( opt.permissive == 0 && ret > 0 )
+        {
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse failed to parse %d certificates\n\n", ret );
+            mbedtls_x509_crt_free( &crt );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+
+        /*
+         * 1.2 Print the certificate(s)
+         */
+        while( cur != NULL )
+        {
+            mbedtls_printf( "  . Peer certificate information    ...\n" );
+            ret = mbedtls_x509_crt_info( (char *) buf, sizeof( buf ) - 1, "      ",
+                                 cur );
+            if( ret == -1 )
+            {
+                mbedtls_printf( " failed\n  !  mbedtls_x509_crt_info returned %d\n\n", ret );
+                mbedtls_x509_crt_free( &crt );
+                goto exit;
+            }
+
+            mbedtls_printf( "%s\n", buf );
+
+            cur = cur->next;
+        }
+
+        /*
+         * 1.3 Verify the certificate
+         */
+        if( verify )
+        {
+            mbedtls_printf( "  . Verifying X.509 certificate..." );
+
+            if( ( ret = mbedtls_x509_crt_verify( &crt, &cacert, &cacrl, NULL, &flags,
+                                         my_verify, NULL ) ) != 0 )
+            {
+                char vrfy_buf[512];
+
+                mbedtls_printf( " failed\n" );
+
+                mbedtls_x509_crt_verify_info( vrfy_buf, sizeof( vrfy_buf ), "  ! ", flags );
+
+                mbedtls_printf( "%s\n", vrfy_buf );
+            }
+            else
+                mbedtls_printf( " ok\n" );
+        }
+
+        mbedtls_x509_crt_free( &crt );
+    }
+    else if( opt.mode == MODE_SSL )
+    {
+        /*
+         * 1. Initialize the RNG and the session data
+         */
+        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 ssl_exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+
+#if defined(MBEDTLS_DEBUG_C)
+        mbedtls_debug_set_threshold( opt.debug_level );
+#endif
+
+        /*
+         * 2. Start the connection
+         */
+        mbedtls_printf( "  . SSL connection to tcp/%s/%s...", opt.server_name,
+                                                              opt.server_port );
+        fflush( stdout );
+
+        if( ( ret = mbedtls_net_connect( &server_fd, opt.server_name,
+                                 opt.server_port, MBEDTLS_NET_PROTO_TCP ) ) != 0 )
+        {
+            mbedtls_printf( " failed\n  ! mbedtls_net_connect returned %d\n\n", ret );
+            goto ssl_exit;
+        }
+
+        /*
+         * 3. Setup stuff
+         */
+        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;
+        }
+
+        if( verify )
+        {
+            mbedtls_ssl_conf_authmode( &conf, MBEDTLS_SSL_VERIFY_REQUIRED );
+            mbedtls_ssl_conf_ca_chain( &conf, &cacert, NULL );
+            mbedtls_ssl_conf_verify( &conf, my_verify, NULL );
+        }
+        else
+            mbedtls_ssl_conf_authmode( &conf, MBEDTLS_SSL_VERIFY_NONE );
+
+        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 ssl_exit;
+        }
+
+        if( ( ret = mbedtls_ssl_set_hostname( &ssl, opt.server_name ) ) != 0 )
+        {
+            mbedtls_printf( " failed\n  ! mbedtls_ssl_set_hostname returned %d\n\n", ret );
+            goto ssl_exit;
+        }
+
+        mbedtls_ssl_set_bio( &ssl, &server_fd, mbedtls_net_send, mbedtls_net_recv, NULL );
+
+        /*
+         * 4. Handshake
+         */
+        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 ssl_exit;
+            }
+        }
+
+        mbedtls_printf( " ok\n" );
+
+        /*
+         * 5. Print the certificate
+         */
+#if !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE)
+        mbedtls_printf( "  . Peer certificate information    ... skipped\n" );
+#else
+        mbedtls_printf( "  . Peer certificate information    ...\n" );
+        ret = mbedtls_x509_crt_info( (char *) buf, sizeof( buf ) - 1, "      ",
+                                     mbedtls_ssl_get_peer_cert( &ssl ) );
+        if( ret == -1 )
+        {
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_info returned %d\n\n", ret );
+            goto ssl_exit;
+        }
+
+        mbedtls_printf( "%s\n", buf );
+#endif /* MBEDTLS_SSL_KEEP_PEER_CERTIFICATE */
+
+        mbedtls_ssl_close_notify( &ssl );
+
+ssl_exit:
+        mbedtls_ssl_free( &ssl );
+        mbedtls_ssl_config_free( &conf );
+    }
+    else
+        goto usage;
+
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+
+    mbedtls_net_free( &server_fd );
+    mbedtls_x509_crt_free( &cacert );
+#if defined(MBEDTLS_X509_CRL_PARSE_C)
+    mbedtls_x509_crl_free( &cacrl );
+#endif
+    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_BIGNUM_C && MBEDTLS_ENTROPY_C && MBEDTLS_SSL_TLS_C &&
+          MBEDTLS_SSL_CLI_C && MBEDTLS_NET_C && MBEDTLS_RSA_C &&
+          MBEDTLS_X509_CRT_PARSE_C && MBEDTLS_FS_IO && MBEDTLS_CTR_DRBG_C */
diff --git a/programs/x509/cert_req.c b/programs/x509/cert_req.c
new file mode 100644
index 0000000..d25ad4c
--- /dev/null
+++ b/programs/x509/cert_req.c
@@ -0,0 +1,453 @@
+/*
+ *  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            exit
+#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_PASSWORD            NULL
+#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_FORCE_KEY_USAGE     0
+#define DFL_NS_CERT_TYPE        0
+#define DFL_FORCE_NS_CERT_TYPE  0
+#define DFL_MD_ALG              MBEDTLS_MD_SHA256
+
+#define USAGE \
+    "\n usage: cert_req param=<>...\n"                  \
+    "\n acceptable parameters:\n"                       \
+    "    filename=%%s         default: keyfile.key\n"   \
+    "    password=%%s         default: NULL\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"              \
+    "    force_key_usage=0/1  default: off\n"           \
+    "                          Add KeyUsage even if it is empty\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"     \
+    "    force_ns_cert_type=0/1 default: off\n"         \
+    "                          Add NsCertType even if it is empty\n"    \
+    "    md=%%s               default: SHA256\n"       \
+    "                          possible values:\n"     \
+    "                          MD4, MD5, SHA1\n"       \
+    "                          SHA224, SHA256\n"       \
+    "                          SHA384, SHA512\n"       \
+    "\n"
+
+#if defined(MBEDTLS_CHECK_PARAMS)
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
+/*
+ * global options
+ */
+struct options
+{
+    const char *filename;       /* filename of the key file             */
+    const char *password;       /* password for 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                      */
+    int force_key_usage;        /* Force adding the KeyUsage extension  */
+    unsigned char ns_cert_type; /* NS cert type                         */
+    int force_ns_cert_type;     /* Force adding NsCertType extension    */
+    mbedtls_md_type_t md_alg;   /* Hash algorithm used for signature.   */
+} 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_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.password            = DFL_PASSWORD;
+    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.force_key_usage     = DFL_FORCE_KEY_USAGE;
+    opt.ns_cert_type        = DFL_NS_CERT_TYPE;
+    opt.force_ns_cert_type  = DFL_FORCE_NS_CERT_TYPE;
+    opt.md_alg              = DFL_MD_ALG;
+
+    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, "password" ) == 0 )
+            opt.password = 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, "md" ) == 0 )
+        {
+            if( strcmp( q, "SHA256" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_SHA256;
+            }
+            else if( strcmp( q, "SHA224" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_SHA224;
+            }
+            else
+#if defined(MBEDTLS_MD5_C)
+            if( strcmp( q, "MD5" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_MD5;
+            }
+            else
+#endif /* MBEDTLS_MD5_C */
+#if defined(MBEDTLS_MD4_C)
+            if( strcmp( q, "MD4" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_MD4;
+            }
+            else
+#endif /* MBEDTLS_MD5_C */
+#if defined(MBEDTLS_SHA1_C)
+            if( strcmp( q, "SHA1" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_SHA1;
+            }
+            else
+#endif /* MBEDTLS_SHA1_C */
+#if defined(MBEDTLS_SHA512_C)
+            if( strcmp( q, "SHA384" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_SHA384;
+            }
+            else
+            if( strcmp( q, "SHA512" ) == 0 )
+            {
+                opt.md_alg = MBEDTLS_MD_SHA512;
+            }
+            else
+#endif /* MBEDTLS_SHA512_C */
+            {
+                goto usage;
+            }
+        }
+        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, "force_key_usage" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0: opt.force_key_usage = 0; break;
+                case 1: opt.force_key_usage = 1; break;
+                default: goto usage;
+            }
+        }
+        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 if( strcmp( p, "force_ns_cert_type" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0: opt.force_ns_cert_type = 0; break;
+                case 1: opt.force_ns_cert_type = 1; break;
+                default: goto usage;
+            }
+        }
+        else
+            goto usage;
+    }
+
+    mbedtls_x509write_csr_set_md_alg( &req, opt.md_alg );
+
+    if( opt.key_usage || opt.force_key_usage == 1 )
+        mbedtls_x509write_csr_set_key_usage( &req, opt.key_usage );
+
+    if( opt.ns_cert_type || opt.force_ns_cert_type == 1 )
+        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, opt.password );
+
+    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 */
diff --git a/programs/x509/cert_write.c b/programs/x509/cert_write.c
new file mode 100644
index 0000000..cd39108
--- /dev/null
+++ b/programs/x509/cert_write.c
@@ -0,0 +1,825 @@
+/*
+ *  Certificate generation and signing
+ *
+ *  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            exit
+#define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
+
+#if !defined(MBEDTLS_X509_CRT_WRITE_C) || \
+    !defined(MBEDTLS_X509_CRT_PARSE_C) || !defined(MBEDTLS_FS_IO) || \
+    !defined(MBEDTLS_ENTROPY_C) || !defined(MBEDTLS_CTR_DRBG_C) || \
+    !defined(MBEDTLS_ERROR_C) || !defined(MBEDTLS_SHA256_C) || \
+    !defined(MBEDTLS_PEM_WRITE_C)
+int main( void )
+{
+    mbedtls_printf( "MBEDTLS_X509_CRT_WRITE_C and/or MBEDTLS_X509_CRT_PARSE_C and/or "
+            "MBEDTLS_FS_IO and/or MBEDTLS_SHA256_C and/or "
+            "MBEDTLS_ENTROPY_C and/or MBEDTLS_CTR_DRBG_C and/or "
+            "MBEDTLS_ERROR_C not defined.\n");
+    return( 0 );
+}
+#else
+
+#include "mbedtls/x509_crt.h"
+#include "mbedtls/x509_csr.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/md.h"
+#include "mbedtls/error.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#if defined(MBEDTLS_X509_CSR_PARSE_C)
+#define USAGE_CSR                                                           \
+    "    request_file=%%s         default: (empty)\n"                           \
+    "                            If request_file is specified, subject_key,\n"  \
+    "                            subject_pwd and subject_name are ignored!\n"
+#else
+#define USAGE_CSR ""
+#endif /* MBEDTLS_X509_CSR_PARSE_C */
+
+#define DFL_ISSUER_CRT          ""
+#define DFL_REQUEST_FILE        ""
+#define DFL_SUBJECT_KEY         "subject.key"
+#define DFL_ISSUER_KEY          "ca.key"
+#define DFL_SUBJECT_PWD         ""
+#define DFL_ISSUER_PWD          ""
+#define DFL_OUTPUT_FILENAME     "cert.crt"
+#define DFL_SUBJECT_NAME        "CN=Cert,O=mbed TLS,C=UK"
+#define DFL_ISSUER_NAME         "CN=CA,O=mbed TLS,C=UK"
+#define DFL_NOT_BEFORE          "20010101000000"
+#define DFL_NOT_AFTER           "20301231235959"
+#define DFL_SERIAL              "1"
+#define DFL_SELFSIGN            0
+#define DFL_IS_CA               0
+#define DFL_MAX_PATHLEN         -1
+#define DFL_KEY_USAGE           0
+#define DFL_NS_CERT_TYPE        0
+#define DFL_VERSION             3
+#define DFL_AUTH_IDENT          1
+#define DFL_SUBJ_IDENT          1
+#define DFL_CONSTRAINTS         1
+#define DFL_DIGEST              MBEDTLS_MD_SHA256
+
+#define USAGE \
+    "\n usage: cert_write param=<>...\n"                \
+    "\n acceptable parameters:\n"                       \
+    USAGE_CSR                                           \
+    "    subject_key=%%s          default: subject.key\n"   \
+    "    subject_pwd=%%s          default: (empty)\n"       \
+    "    subject_name=%%s         default: CN=Cert,O=mbed TLS,C=UK\n"   \
+    "\n"                                                \
+    "    issuer_crt=%%s           default: (empty)\n"       \
+    "                            If issuer_crt is specified, issuer_name is\n"  \
+    "                            ignored!\n"                \
+    "    issuer_name=%%s          default: CN=CA,O=mbed TLS,C=UK\n"     \
+    "\n"                                                \
+    "    selfsign=%%d             default: 0 (false)\n"     \
+    "                            If selfsign is enabled, issuer_name and\n" \
+    "                            issuer_key are required (issuer_crt and\n" \
+    "                            subject_* are ignored\n"   \
+    "    issuer_key=%%s           default: ca.key\n"        \
+    "    issuer_pwd=%%s           default: (empty)\n"       \
+    "    output_file=%%s          default: cert.crt\n"      \
+    "    serial=%%s               default: 1\n"             \
+    "    not_before=%%s           default: 20010101000000\n"\
+    "    not_after=%%s            default: 20301231235959\n"\
+    "    is_ca=%%d                default: 0 (disabled)\n"  \
+    "    max_pathlen=%%d          default: -1 (none)\n"     \
+    "    md=%%s                   default: SHA256\n"        \
+    "                            Supported values:\n"       \
+    "                            MD5, SHA1, SHA256, SHA512\n"\
+    "    version=%%d              default: 3\n"            \
+    "                            Possible values: 1, 2, 3\n"\
+    "    subject_identifier=%%s   default: 1\n"             \
+    "                            Possible values: 0, 1\n"   \
+    "                            (Considered for v3 only)\n"\
+    "    authority_identifier=%%s default: 1\n"             \
+    "                            Possible values: 0, 1\n"   \
+    "                            (Considered for v3 only)\n"\
+    "    basic_constraints=%%d    default: 1\n"             \
+    "                            Possible values: 0, 1\n"   \
+    "                            (Considered for v3 only)\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"              \
+    "                            (Considered for v3 only)\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"
+
+#if defined(MBEDTLS_CHECK_PARAMS)
+#define mbedtls_exit            exit
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
+/*
+ * global options
+ */
+struct options
+{
+    const char *issuer_crt;     /* filename of the issuer certificate   */
+    const char *request_file;   /* filename of the certificate request  */
+    const char *subject_key;    /* filename of the subject key file     */
+    const char *issuer_key;     /* filename of the issuer key file      */
+    const char *subject_pwd;    /* password for the subject key file    */
+    const char *issuer_pwd;     /* password for the issuer key file     */
+    const char *output_file;    /* where to store the constructed CRT   */
+    const char *subject_name;   /* subject name for certificate         */
+    const char *issuer_name;    /* issuer name for certificate          */
+    const char *not_before;     /* validity period not before           */
+    const char *not_after;      /* validity period not after            */
+    const char *serial;         /* serial number string                 */
+    int selfsign;               /* selfsign the certificate             */
+    int is_ca;                  /* is a CA certificate                  */
+    int max_pathlen;            /* maximum CA path length               */
+    int authority_identifier;   /* add authority identifier to CRT      */
+    int subject_identifier;     /* add subject identifier to CRT        */
+    int basic_constraints;      /* add basic constraints ext to CRT     */
+    int version;                /* CRT version                          */
+    mbedtls_md_type_t md;       /* Hash used for signing                */
+    unsigned char key_usage;    /* key usage flags                      */
+    unsigned char ns_cert_type; /* NS cert type                         */
+} opt;
+
+int write_certificate( mbedtls_x509write_cert *crt, 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_crt_pem( crt, 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_x509_crt issuer_crt;
+    mbedtls_pk_context loaded_issuer_key, loaded_subject_key;
+    mbedtls_pk_context *issuer_key = &loaded_issuer_key,
+                *subject_key = &loaded_subject_key;
+    char buf[1024];
+    char issuer_name[256];
+    int i;
+    char *p, *q, *r;
+#if defined(MBEDTLS_X509_CSR_PARSE_C)
+    char subject_name[256];
+    mbedtls_x509_csr csr;
+#endif
+    mbedtls_x509write_cert crt;
+    mbedtls_mpi serial;
+    mbedtls_entropy_context entropy;
+    mbedtls_ctr_drbg_context ctr_drbg;
+    const char *pers = "crt example app";
+
+    /*
+     * Set to sane values
+     */
+    mbedtls_x509write_crt_init( &crt );
+    mbedtls_pk_init( &loaded_issuer_key );
+    mbedtls_pk_init( &loaded_subject_key );
+    mbedtls_mpi_init( &serial );
+    mbedtls_ctr_drbg_init( &ctr_drbg );
+    mbedtls_entropy_init( &entropy );
+#if defined(MBEDTLS_X509_CSR_PARSE_C)
+    mbedtls_x509_csr_init( &csr );
+#endif
+    mbedtls_x509_crt_init( &issuer_crt );
+    memset( buf, 0, 1024 );
+
+    if( argc == 0 )
+    {
+    usage:
+        mbedtls_printf( USAGE );
+        goto exit;
+    }
+
+    opt.issuer_crt          = DFL_ISSUER_CRT;
+    opt.request_file        = DFL_REQUEST_FILE;
+    opt.subject_key         = DFL_SUBJECT_KEY;
+    opt.issuer_key          = DFL_ISSUER_KEY;
+    opt.subject_pwd         = DFL_SUBJECT_PWD;
+    opt.issuer_pwd          = DFL_ISSUER_PWD;
+    opt.output_file         = DFL_OUTPUT_FILENAME;
+    opt.subject_name        = DFL_SUBJECT_NAME;
+    opt.issuer_name         = DFL_ISSUER_NAME;
+    opt.not_before          = DFL_NOT_BEFORE;
+    opt.not_after           = DFL_NOT_AFTER;
+    opt.serial              = DFL_SERIAL;
+    opt.selfsign            = DFL_SELFSIGN;
+    opt.is_ca               = DFL_IS_CA;
+    opt.max_pathlen         = DFL_MAX_PATHLEN;
+    opt.key_usage           = DFL_KEY_USAGE;
+    opt.ns_cert_type        = DFL_NS_CERT_TYPE;
+    opt.version             = DFL_VERSION - 1;
+    opt.md                  = DFL_DIGEST;
+    opt.subject_identifier   = DFL_SUBJ_IDENT;
+    opt.authority_identifier = DFL_AUTH_IDENT;
+    opt.basic_constraints    = DFL_CONSTRAINTS;
+
+    for( i = 1; i < argc; i++ )
+    {
+
+        p = argv[i];
+        if( ( q = strchr( p, '=' ) ) == NULL )
+            goto usage;
+        *q++ = '\0';
+
+        if( strcmp( p, "request_file" ) == 0 )
+            opt.request_file = q;
+        else if( strcmp( p, "subject_key" ) == 0 )
+            opt.subject_key = q;
+        else if( strcmp( p, "issuer_key" ) == 0 )
+            opt.issuer_key = q;
+        else if( strcmp( p, "subject_pwd" ) == 0 )
+            opt.subject_pwd = q;
+        else if( strcmp( p, "issuer_pwd" ) == 0 )
+            opt.issuer_pwd = q;
+        else if( strcmp( p, "issuer_crt" ) == 0 )
+            opt.issuer_crt = q;
+        else if( strcmp( p, "output_file" ) == 0 )
+            opt.output_file = q;
+        else if( strcmp( p, "subject_name" ) == 0 )
+        {
+            opt.subject_name = q;
+        }
+        else if( strcmp( p, "issuer_name" ) == 0 )
+        {
+            opt.issuer_name = q;
+        }
+        else if( strcmp( p, "not_before" ) == 0 )
+        {
+            opt.not_before = q;
+        }
+        else if( strcmp( p, "not_after" ) == 0 )
+        {
+            opt.not_after = q;
+        }
+        else if( strcmp( p, "serial" ) == 0 )
+        {
+            opt.serial = q;
+        }
+        else if( strcmp( p, "authority_identifier" ) == 0 )
+        {
+            opt.authority_identifier = atoi( q );
+            if( opt.authority_identifier != 0 &&
+                opt.authority_identifier != 1 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        else if( strcmp( p, "subject_identifier" ) == 0 )
+        {
+            opt.subject_identifier = atoi( q );
+            if( opt.subject_identifier != 0 &&
+                opt.subject_identifier != 1 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        else if( strcmp( p, "basic_constraints" ) == 0 )
+        {
+            opt.basic_constraints = atoi( q );
+            if( opt.basic_constraints != 0 &&
+                opt.basic_constraints != 1 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        else if( strcmp( p, "md" ) == 0 )
+        {
+            if( strcmp( q, "SHA1" ) == 0 )
+                opt.md = MBEDTLS_MD_SHA1;
+            else if( strcmp( q, "SHA256" ) == 0 )
+                opt.md = MBEDTLS_MD_SHA256;
+            else if( strcmp( q, "SHA512" ) == 0 )
+                opt.md = MBEDTLS_MD_SHA512;
+            else if( strcmp( q, "MD5" ) == 0 )
+                opt.md = MBEDTLS_MD_MD5;
+            else
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        else if( strcmp( p, "version" ) == 0 )
+        {
+            opt.version = atoi( q );
+            if( opt.version < 1 || opt.version > 3 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+            opt.version--;
+        }
+        else if( strcmp( p, "selfsign" ) == 0 )
+        {
+            opt.selfsign = atoi( q );
+            if( opt.selfsign < 0 || opt.selfsign > 1 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        else if( strcmp( p, "is_ca" ) == 0 )
+        {
+            opt.is_ca = atoi( q );
+            if( opt.is_ca < 0 || opt.is_ca > 1 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        else if( strcmp( p, "max_pathlen" ) == 0 )
+        {
+            opt.max_pathlen = atoi( q );
+            if( opt.max_pathlen < -1 || opt.max_pathlen > 127 )
+            {
+                mbedtls_printf( "Invalid argument for option %s\n", p );
+                goto usage;
+            }
+        }
+        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
+                {
+                    mbedtls_printf( "Invalid argument for option %s\n", p );
+                    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
+                {
+                    mbedtls_printf( "Invalid argument for option %s\n", p );
+                    goto usage;
+                }
+
+                q = r;
+            }
+        }
+        else
+            goto usage;
+    }
+
+    mbedtls_printf("\n");
+
+    /*
+     * 0. Seed the PRNG
+     */
+    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_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_ctr_drbg_seed returned %d - %s\n",
+                        ret, buf );
+        goto exit;
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    // Parse serial to MPI
+    //
+    mbedtls_printf( "  . Reading serial number..." );
+    fflush( stdout );
+
+    if( ( ret = mbedtls_mpi_read_string( &serial, 10, opt.serial ) ) != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_mpi_read_string "
+                        "returned -0x%04x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    // Parse issuer certificate if present
+    //
+    if( !opt.selfsign && strlen( opt.issuer_crt ) )
+    {
+        /*
+         * 1.0.a. Load the certificates
+         */
+        mbedtls_printf( "  . Loading the issuer certificate ..." );
+        fflush( stdout );
+
+        if( ( ret = mbedtls_x509_crt_parse_file( &issuer_crt, opt.issuer_crt ) ) != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509_crt_parse_file "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        ret = mbedtls_x509_dn_gets( issuer_name, sizeof(issuer_name),
+                                 &issuer_crt.subject );
+        if( ret < 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509_dn_gets "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        opt.issuer_name = issuer_name;
+
+        mbedtls_printf( " ok\n" );
+    }
+
+#if defined(MBEDTLS_X509_CSR_PARSE_C)
+    // Parse certificate request if present
+    //
+    if( !opt.selfsign && strlen( opt.request_file ) )
+    {
+        /*
+         * 1.0.b. Load the CSR
+         */
+        mbedtls_printf( "  . Loading the certificate request ..." );
+        fflush( stdout );
+
+        if( ( ret = mbedtls_x509_csr_parse_file( &csr, opt.request_file ) ) != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509_csr_parse_file "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        ret = mbedtls_x509_dn_gets( subject_name, sizeof(subject_name),
+                                 &csr.subject );
+        if( ret < 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509_dn_gets "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        opt.subject_name = subject_name;
+        subject_key = &csr.pk;
+
+        mbedtls_printf( " ok\n" );
+    }
+#endif /* MBEDTLS_X509_CSR_PARSE_C */
+
+    /*
+     * 1.1. Load the keys
+     */
+    if( !opt.selfsign && !strlen( opt.request_file ) )
+    {
+        mbedtls_printf( "  . Loading the subject key ..." );
+        fflush( stdout );
+
+        ret = mbedtls_pk_parse_keyfile( &loaded_subject_key, opt.subject_key,
+                                 opt.subject_pwd );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_pk_parse_keyfile "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+    }
+
+    mbedtls_printf( "  . Loading the issuer key ..." );
+    fflush( stdout );
+
+    ret = mbedtls_pk_parse_keyfile( &loaded_issuer_key, opt.issuer_key,
+                             opt.issuer_pwd );
+    if( ret != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_pk_parse_keyfile "
+                        "returned -x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    // Check if key and issuer certificate match
+    //
+    if( strlen( opt.issuer_crt ) )
+    {
+        if( mbedtls_pk_check_pair( &issuer_crt.pk, issuer_key ) != 0 )
+        {
+            mbedtls_printf( " failed\n  !  issuer_key does not match "
+                            "issuer certificate\n\n" );
+            goto exit;
+        }
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    if( opt.selfsign )
+    {
+        opt.subject_name = opt.issuer_name;
+        subject_key = issuer_key;
+    }
+
+    mbedtls_x509write_crt_set_subject_key( &crt, subject_key );
+    mbedtls_x509write_crt_set_issuer_key( &crt, issuer_key );
+
+    /*
+     * 1.0. Check the names for validity
+     */
+    if( ( ret = mbedtls_x509write_crt_set_subject_name( &crt, opt.subject_name ) ) != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_subject_name "
+                        "returned -0x%04x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    if( ( ret = mbedtls_x509write_crt_set_issuer_name( &crt, opt.issuer_name ) ) != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_issuer_name "
+                        "returned -0x%04x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    mbedtls_printf( "  . Setting certificate values ..." );
+    fflush( stdout );
+
+    mbedtls_x509write_crt_set_version( &crt, opt.version );
+    mbedtls_x509write_crt_set_md_alg( &crt, opt.md );
+
+    ret = mbedtls_x509write_crt_set_serial( &crt, &serial );
+    if( ret != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_serial "
+                        "returned -0x%04x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    ret = mbedtls_x509write_crt_set_validity( &crt, opt.not_before, opt.not_after );
+    if( ret != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_validity "
+                        "returned -0x%04x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    if( opt.version == MBEDTLS_X509_CRT_VERSION_3 &&
+        opt.basic_constraints != 0 )
+    {
+        mbedtls_printf( "  . Adding the Basic Constraints extension ..." );
+        fflush( stdout );
+
+        ret = mbedtls_x509write_crt_set_basic_constraints( &crt, opt.is_ca,
+                                                           opt.max_pathlen );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  x509write_crt_set_basic_contraints "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+    }
+
+#if defined(MBEDTLS_SHA1_C)
+    if( opt.version == MBEDTLS_X509_CRT_VERSION_3 &&
+        opt.subject_identifier != 0 )
+    {
+        mbedtls_printf( "  . Adding the Subject Key Identifier ..." );
+        fflush( stdout );
+
+        ret = mbedtls_x509write_crt_set_subject_key_identifier( &crt );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_subject"
+                            "_key_identifier returned -0x%04x - %s\n\n",
+                            -ret, buf );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+    }
+
+    if( opt.version == MBEDTLS_X509_CRT_VERSION_3 &&
+        opt.authority_identifier != 0 )
+    {
+        mbedtls_printf( "  . Adding the Authority Key Identifier ..." );
+        fflush( stdout );
+
+        ret = mbedtls_x509write_crt_set_authority_key_identifier( &crt );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_authority_"
+                            "key_identifier returned -0x%04x - %s\n\n",
+                            -ret, buf );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+    }
+#endif /* MBEDTLS_SHA1_C */
+
+    if( opt.version == MBEDTLS_X509_CRT_VERSION_3 &&
+        opt.key_usage != 0 )
+    {
+        mbedtls_printf( "  . Adding the Key Usage extension ..." );
+        fflush( stdout );
+
+        ret = mbedtls_x509write_crt_set_key_usage( &crt, opt.key_usage );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_key_usage "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+    }
+
+    if( opt.version == MBEDTLS_X509_CRT_VERSION_3 &&
+        opt.ns_cert_type != 0 )
+    {
+        mbedtls_printf( "  . Adding the NS Cert Type extension ..." );
+        fflush( stdout );
+
+        ret = mbedtls_x509write_crt_set_ns_cert_type( &crt, opt.ns_cert_type );
+        if( ret != 0 )
+        {
+            mbedtls_strerror( ret, buf, 1024 );
+            mbedtls_printf( " failed\n  !  mbedtls_x509write_crt_set_ns_cert_type "
+                            "returned -0x%04x - %s\n\n", -ret, buf );
+            goto exit;
+        }
+
+        mbedtls_printf( " ok\n" );
+    }
+
+    /*
+     * 1.2. Writing the certificate
+     */
+    mbedtls_printf( "  . Writing the certificate..." );
+    fflush( stdout );
+
+    if( ( ret = write_certificate( &crt, opt.output_file,
+                                   mbedtls_ctr_drbg_random, &ctr_drbg ) ) != 0 )
+    {
+        mbedtls_strerror( ret, buf, 1024 );
+        mbedtls_printf( " failed\n  !  write_certificate -0x%04x - %s\n\n",
+                        -ret, buf );
+        goto exit;
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+#if defined(MBEDTLS_X509_CSR_PARSE_C)
+    mbedtls_x509_csr_free( &csr );
+#endif /* MBEDTLS_X509_CSR_PARSE_C */
+    mbedtls_x509_crt_free( &issuer_crt );
+    mbedtls_x509write_crt_free( &crt );
+    mbedtls_pk_free( &loaded_subject_key );
+    mbedtls_pk_free( &loaded_issuer_key );
+    mbedtls_mpi_free( &serial );
+    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_CRT_WRITE_C && MBEDTLS_X509_CRT_PARSE_C &&
+          MBEDTLS_FS_IO && MBEDTLS_ENTROPY_C && MBEDTLS_CTR_DRBG_C &&
+          MBEDTLS_ERROR_C && MBEDTLS_PEM_WRITE_C */
diff --git a/programs/x509/crl_app.c b/programs/x509/crl_app.c
new file mode 100644
index 0000000..a951570
--- /dev/null
+++ b/programs/x509/crl_app.c
@@ -0,0 +1,164 @@
+/*
+ *  CRL reading application
+ *
+ *  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            exit
+#define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
+
+#if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) ||  \
+    !defined(MBEDTLS_X509_CRL_PARSE_C) || !defined(MBEDTLS_FS_IO)
+int main( void )
+{
+    mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or "
+           "MBEDTLS_X509_CRL_PARSE_C and/or MBEDTLS_FS_IO not defined.\n");
+    return( 0 );
+}
+#else
+
+#include "mbedtls/x509_crl.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define DFL_FILENAME            "crl.pem"
+#define DFL_DEBUG_LEVEL         0
+
+#define USAGE \
+    "\n usage: crl_app param=<>...\n"                   \
+    "\n acceptable parameters:\n"                       \
+    "    filename=%%s         default: crl.pem\n"      \
+    "\n"
+
+#if defined(MBEDTLS_CHECK_PARAMS)
+#define mbedtls_exit            exit
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
+/*
+ * global options
+ */
+struct options
+{
+    const char *filename;       /* filename of the certificate file     */
+} opt;
+
+int main( int argc, char *argv[] )
+{
+    int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
+    unsigned char buf[100000];
+    mbedtls_x509_crl crl;
+    int i;
+    char *p, *q;
+
+    /*
+     * Set to sane values
+     */
+    mbedtls_x509_crl_init( &crl );
+
+    if( argc == 0 )
+    {
+    usage:
+        mbedtls_printf( USAGE );
+        goto exit;
+    }
+
+    opt.filename            = DFL_FILENAME;
+
+    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
+            goto usage;
+    }
+
+    /*
+     * 1.1. Load the CRL
+     */
+    mbedtls_printf( "\n  . Loading the CRL ..." );
+    fflush( stdout );
+
+    ret = mbedtls_x509_crl_parse_file( &crl, opt.filename );
+
+    if( ret != 0 )
+    {
+        mbedtls_printf( " failed\n  !  mbedtls_x509_crl_parse_file returned %d\n\n", ret );
+        mbedtls_x509_crl_free( &crl );
+        goto exit;
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    /*
+     * 1.2 Print the CRL
+     */
+    mbedtls_printf( "  . CRL information    ...\n" );
+    ret = mbedtls_x509_crl_info( (char *) buf, sizeof( buf ) - 1, "      ", &crl );
+    if( ret == -1 )
+    {
+        mbedtls_printf( " failed\n  !  mbedtls_x509_crl_info returned %d\n\n", ret );
+        mbedtls_x509_crl_free( &crl );
+        goto exit;
+    }
+
+    mbedtls_printf( "%s\n", buf );
+
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+    mbedtls_x509_crl_free( &crl );
+
+#if defined(_WIN32)
+    mbedtls_printf( "  + Press Enter to exit this program.\n" );
+    fflush( stdout ); getchar();
+#endif
+
+    return( exit_code );
+}
+#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && MBEDTLS_X509_CRL_PARSE_C &&
+          MBEDTLS_FS_IO */
diff --git a/programs/x509/req_app.c b/programs/x509/req_app.c
new file mode 100644
index 0000000..04ad119
--- /dev/null
+++ b/programs/x509/req_app.c
@@ -0,0 +1,164 @@
+/*
+ *  Certificate request reading application
+ *
+ *  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            exit
+#define MBEDTLS_EXIT_SUCCESS    EXIT_SUCCESS
+#define MBEDTLS_EXIT_FAILURE    EXIT_FAILURE
+#endif /* MBEDTLS_PLATFORM_C */
+
+#if !defined(MBEDTLS_BIGNUM_C) || !defined(MBEDTLS_RSA_C) ||  \
+    !defined(MBEDTLS_X509_CSR_PARSE_C) || !defined(MBEDTLS_FS_IO)
+int main( void )
+{
+    mbedtls_printf("MBEDTLS_BIGNUM_C and/or MBEDTLS_RSA_C and/or "
+           "MBEDTLS_X509_CSR_PARSE_C and/or MBEDTLS_FS_IO not defined.\n");
+    return( 0 );
+}
+#else
+
+#include "mbedtls/x509_csr.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define DFL_FILENAME            "cert.req"
+#define DFL_DEBUG_LEVEL         0
+
+#define USAGE \
+    "\n usage: req_app param=<>...\n"                   \
+    "\n acceptable parameters:\n"                       \
+    "    filename=%%s         default: cert.req\n"      \
+    "\n"
+
+#if defined(MBEDTLS_CHECK_PARAMS)
+#define mbedtls_exit            exit
+void mbedtls_param_failed( const char *failure_condition,
+                           const char *file,
+                           int line )
+{
+    mbedtls_printf( "%s:%i: Input param failed - %s\n",
+                    file, line, failure_condition );
+    mbedtls_exit( MBEDTLS_EXIT_FAILURE );
+}
+#endif
+
+/*
+ * global options
+ */
+struct options
+{
+    const char *filename;       /* filename of the certificate request  */
+} opt;
+
+int main( int argc, char *argv[] )
+{
+    int ret = 1;
+    int exit_code = MBEDTLS_EXIT_FAILURE;
+    unsigned char buf[100000];
+    mbedtls_x509_csr csr;
+    int i;
+    char *p, *q;
+
+    /*
+     * Set to sane values
+     */
+    mbedtls_x509_csr_init( &csr );
+
+    if( argc == 0 )
+    {
+    usage:
+        mbedtls_printf( USAGE );
+        goto exit;
+    }
+
+    opt.filename            = DFL_FILENAME;
+
+    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
+            goto usage;
+    }
+
+    /*
+     * 1.1. Load the CSR
+     */
+    mbedtls_printf( "\n  . Loading the CSR ..." );
+    fflush( stdout );
+
+    ret = mbedtls_x509_csr_parse_file( &csr, opt.filename );
+
+    if( ret != 0 )
+    {
+        mbedtls_printf( " failed\n  !  mbedtls_x509_csr_parse_file returned %d\n\n", ret );
+        mbedtls_x509_csr_free( &csr );
+        goto exit;
+    }
+
+    mbedtls_printf( " ok\n" );
+
+    /*
+     * 1.2 Print the CSR
+     */
+    mbedtls_printf( "  . CSR information    ...\n" );
+    ret = mbedtls_x509_csr_info( (char *) buf, sizeof( buf ) - 1, "      ", &csr );
+    if( ret == -1 )
+    {
+        mbedtls_printf( " failed\n  !  mbedtls_x509_csr_info returned %d\n\n", ret );
+        mbedtls_x509_csr_free( &csr );
+        goto exit;
+    }
+
+    mbedtls_printf( "%s\n", buf );
+
+    exit_code = MBEDTLS_EXIT_SUCCESS;
+
+exit:
+    mbedtls_x509_csr_free( &csr );
+
+#if defined(_WIN32)
+    mbedtls_printf( "  + Press Enter to exit this program.\n" );
+    fflush( stdout ); getchar();
+#endif
+
+    return( exit_code );
+}
+#endif /* MBEDTLS_BIGNUM_C && MBEDTLS_RSA_C && MBEDTLS_X509_CSR_PARSE_C &&
+          MBEDTLS_FS_IO */