diff --git a/programs/x509/CMakeLists.txt b/programs/x509/CMakeLists.txt
index d07cff8..8aaa4ac 100644
--- a/programs/x509/CMakeLists.txt
+++ b/programs/x509/CMakeLists.txt
@@ -19,6 +19,9 @@
 add_executable(cert_req cert_req.c)
 target_link_libraries(cert_req ${libs})
 
-install(TARGETS cert_app crl_app cert_req
+add_executable(cert_write cert_write.c)
+target_link_libraries(cert_write ${libs})
+
+install(TARGETS cert_app crl_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_write.c b/programs/x509/cert_write.c
new file mode 100644
index 0000000..59c49b2
--- /dev/null
+++ b/programs/x509/cert_write.c
@@ -0,0 +1,423 @@
+/*
+ *  Certificate generation and signing
+ *
+ *  Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ *  This file is part of PolarSSL (http://www.polarssl.org)
+ *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ *  All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef _CRT_SECURE_NO_DEPRECATE
+#define _CRT_SECURE_NO_DEPRECATE 1
+#endif
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+#include "polarssl/config.h"
+
+#include "polarssl/error.h"
+#include "polarssl/rsa.h"
+#include "polarssl/x509.h"
+#include "polarssl/base64.h"
+#include "polarssl/x509write.h"
+#include "polarssl/oid.h"
+
+#if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_RSA_C) ||         \
+    !defined(POLARSSL_X509_WRITE_C) || !defined(POLARSSL_FS_IO)
+int main( int argc, char *argv[] )
+{
+    ((void) argc);
+    ((void) argv);
+
+    printf("POLARSSL_BIGNUM_C and/or POLARSSL_RSA_C and/or "
+           "POLARSSL_X509_WRITE_C and/or POLARSSL_FS_IO not defined.\n");
+    return( 0 );
+}
+#else
+
+#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=PolarSSL,C=NL"
+#define DFL_ISSUER_NAME         "CN=CA,O=PolarSSL,C=NL"
+#define DFL_NOT_BEFORE          "20010101000000"
+#define DFL_NOT_AFTER           "20301231235959"
+#define DFL_SERIAL              "1"
+#define DFL_KEY_USAGE           0
+#define DFL_NS_CERT_TYPE        0
+
+/*
+ * global options
+ */
+struct options
+{
+    char *subject_key;          /* filename of the subject key file     */
+    char *issuer_key;           /* filename of the issuer key file      */
+    char *subject_pwd;          /* password for the subject key file    */
+    char *issuer_pwd;           /* password for the issuer key file     */
+    char *output_file;          /* where to store the constructed key file  */
+    char *subject_name;         /* subject name for certificate         */
+    char *issuer_name;          /* issuer name for certificate          */
+    char *not_before;           /* validity period not before           */
+    char *not_after;            /* validity period not after            */
+    char *serial;               /* serial number string                 */
+    unsigned char key_usage;    /* key usage flags                      */
+    unsigned char ns_cert_type; /* NS cert type                         */
+} opt;
+
+int write_certificate( x509write_cert *crt, char *output_file )
+{
+    int ret;
+    FILE *f;
+    unsigned char output_buf[4096];
+    size_t len = 0;
+
+    memset( output_buf, 0, 4096 );
+    if( ( ret = x509write_crt_pem( crt, output_buf, 4096 ) ) < 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 )
+        return( -1 );
+
+    fclose(f);
+
+    return( 0 );
+}
+
+#define USAGE \
+    "\n usage: cert_write param=<>...\n"                \
+    "\n acceptable parameters:\n"                       \
+    "    subject_key=%%s      default: subject.key\n"   \
+    "    subject_pwd=%%s      default: (empty)\n"       \
+    "    issuer_key=%%s       default: ca.key\n"        \
+    "    issuer_pwd=%%s       default: (empty)\n"       \
+    "    output_file=%%s      default: cert.crt\n"      \
+    "    subject_name=%%s     default: CN=Cert,O=PolarSSL,C=NL\n"   \
+    "    issuer_name=%%s      default: CN=CA,O=PolarSSL,C=NL\n"     \
+    "    serial=%%s           default: 1\n"             \
+    "    not_before=%%s       default: 20010101000000\n"\
+    "    not_after=%%s        default: 20301231235959\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_certificate_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"
+
+int main( int argc, char *argv[] )
+{
+    int ret = 0;
+    rsa_context issuer_rsa, subject_rsa;
+    char buf[1024];
+    int i, j, n;
+    char *p, *q, *r;
+    x509write_cert crt;
+    mpi serial;
+
+    /*
+     * Set to sane values
+     */
+    x509write_crt_init( &crt );
+    x509write_crt_set_md_alg( &crt, POLARSSL_MD_SHA1 );
+    rsa_init( &issuer_rsa, RSA_PKCS_V15, 0 );
+    rsa_init( &subject_rsa, RSA_PKCS_V15, 0 );
+    mpi_init( &serial );
+    memset( buf, 0, 1024 );
+
+    if( argc == 0 )
+    {
+    usage:
+        printf( USAGE );
+        ret = 1;
+        goto exit;
+    }
+
+    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.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';
+
+        n = strlen( p );
+        for( j = 0; j < n; j++ )
+        {
+            if( argv[i][j] >= 'A' && argv[i][j] <= 'Z' )
+                argv[i][j] |= 0x20;
+        }
+
+        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, "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, "key_usage" ) == 0 )
+        {
+            while( q != NULL )
+            {
+                if( ( r = strchr( q, ',' ) ) != NULL )
+                    *r++ = '\0';
+
+                if( strcmp( q, "digital_signature" ) == 0 )
+                    opt.key_usage |= KU_DIGITAL_SIGNATURE;
+                else if( strcmp( q, "non_repudiation" ) == 0 )
+                    opt.key_usage |= KU_NON_REPUDIATION;
+                else if( strcmp( q, "key_encipherment" ) == 0 )
+                    opt.key_usage |= KU_KEY_ENCIPHERMENT;
+                else if( strcmp( q, "data_encipherment" ) == 0 )
+                    opt.key_usage |= KU_DATA_ENCIPHERMENT;
+                else if( strcmp( q, "key_agreement" ) == 0 )
+                    opt.key_usage |= KU_KEY_AGREEMENT;
+                else if( strcmp( q, "key_cert_sign" ) == 0 )
+                    opt.key_usage |= KU_KEY_CERT_SIGN;
+                else if( strcmp( q, "crl_sign" ) == 0 )
+                    opt.key_usage |= 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 |= NS_CERT_TYPE_SSL_CLIENT;
+                else if( strcmp( q, "ssl_server" ) == 0 )
+                    opt.ns_cert_type |= NS_CERT_TYPE_SSL_SERVER;
+                else if( strcmp( q, "email" ) == 0 )
+                    opt.ns_cert_type |= NS_CERT_TYPE_EMAIL;
+                else if( strcmp( q, "object_signing" ) == 0 )
+                    opt.ns_cert_type |= NS_CERT_TYPE_OBJECT_SIGNING;
+                else if( strcmp( q, "ssl_ca" ) == 0 )
+                    opt.ns_cert_type |= NS_CERT_TYPE_SSL_CA;
+                else if( strcmp( q, "email_ca" ) == 0 )
+                    opt.ns_cert_type |= NS_CERT_TYPE_EMAIL_CA;
+                else if( strcmp( q, "object_signing_ca" ) == 0 )
+                    opt.ns_cert_type |= NS_CERT_TYPE_OBJECT_SIGNING_CA;
+                else
+                    goto usage;
+
+                q = r;
+            }
+        }
+        else
+            goto usage;
+    }
+
+    // Parse serial to MPI
+    //
+    if( ( ret = mpi_read_string( &serial, 10, opt.serial ) ) != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  mpi_read_string returned -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+/*
+    if( opt.key_usage )
+        x509write_csr_set_key_usage( &req, opt.key_usage );
+
+    if( opt.ns_cert_type )
+        x509write_csr_set_ns_cert_type( &req, opt.ns_cert_type );
+*/
+    /*
+     * 1.0. Check the names for validity
+     */
+    if( ( ret = x509write_crt_set_subject_name( &crt, opt.subject_name ) ) != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  x509write_crt_set_subject_name returned -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    if( ( ret = x509write_crt_set_issuer_name( &crt, opt.issuer_name ) ) != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  x509write_crt_set_issuer_name returned -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    /*
+     * 1.1. Load the keys
+     */
+    printf( "\n  . Loading the subject key ..." );
+    fflush( stdout );
+
+    ret = x509parse_keyfile_rsa( &subject_rsa, opt.subject_key, opt.subject_pwd );
+
+    if( ret != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  x509parse_keyfile_rsa returned -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    x509write_crt_set_subject_key( &crt, &subject_rsa );
+
+    printf( " ok\n" );
+
+    printf( "  . Loading the issuer key ..." );
+    fflush( stdout );
+
+    ret = x509parse_keyfile_rsa( &issuer_rsa, opt.issuer_key, opt.issuer_pwd );
+
+    if( ret != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  x509parse_keyfile_rsa returned -x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    x509write_crt_set_issuer_key( &crt, &issuer_rsa );
+
+    printf( " ok\n" );
+
+    printf( "  . Setting certificate values ..." );
+    fflush( stdout );
+
+    ret = x509write_crt_set_serial( &crt, &serial );
+    if( ret != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  x509write_crt_set_serial returned -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    ret = x509write_crt_set_validity( &crt, opt.not_before, opt.not_after );
+    if( ret != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  x509write_crt_set_validity returned -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    printf( " ok\n" );
+
+    /*
+     * 1.2. Writing the request
+     */
+    printf( "  . Writing the certificate..." );
+    fflush( stdout );
+
+    if( ( ret = write_certificate( &crt, opt.output_file ) ) != 0 )
+    {
+#ifdef POLARSSL_ERROR_C
+        error_strerror( ret, buf, 1024 );
+#endif
+        printf( " failed\n  !  write_certifcate -0x%02x - %s\n\n", -ret, buf );
+        goto exit;
+    }
+
+    printf( " ok\n" );
+
+exit:
+    x509write_crt_free( &crt );
+    rsa_free( &subject_rsa );
+    rsa_free( &issuer_rsa );
+    mpi_free( &serial );
+
+#if defined(_WIN32)
+    printf( "  + Press Enter to exit this program.\n" );
+    fflush( stdout ); getchar();
+#endif
+
+    return( ret );
+}
+#endif /* POLARSSL_BIGNUM_C && POLARSSL_RSA_C &&
+          POLARSSet_serial_X509_WRITE_C && POLARSSL_FS_IO */