diff --git a/library/x509write.c b/library/x509write.c
new file mode 100644
index 0000000..b114e70
--- /dev/null
+++ b/library/x509write.c
@@ -0,0 +1,233 @@
+/*
+ * X509 buffer writing functionality
+ *
+ *  Copyright (C) 2006-2012, 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.
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_X509_WRITE_C)
+
+#include "polarssl/asn1write.h"
+#include "polarssl/x509write.h"
+#include "polarssl/x509.h"
+#include "polarssl/sha1.h"
+
+int x509_write_pubkey_der( unsigned char *buf, size_t size, rsa_context *rsa )
+{
+    int ret;
+    unsigned char *c;
+    size_t len = 0;
+
+    c = buf + size - 1;
+
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->E ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->N ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    if( c - buf < 1 )
+        return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
+
+    *--c = 0;
+    len += 1;
+
+    ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_BIT_STRING ) );
+
+    ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( &c, buf, OID_PKCS1_RSA ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    return( len );
+}
+
+int x509_write_key_der( unsigned char *buf, size_t size, rsa_context *rsa )
+{
+    int ret;
+    unsigned char *c;
+    size_t len = 0;
+
+    c = buf + size - 1;
+
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->QP ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->DQ ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->DP ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->Q ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->P ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->D ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->E ) );
+    ASN1_CHK_ADD( len, asn1_write_mpi( &c, buf, &rsa->N ) );
+    ASN1_CHK_ADD( len, asn1_write_int( &c, buf, 0 ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( &c, buf, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    // TODO: Make NON RSA Specific variant later on
+/*    *--c = 0;
+    len += 1;
+
+    len += asn1_write_len( &c, len);
+    len += asn1_write_tag( &c, ASN1_BIT_STRING );
+
+    len += asn1_write_oid( &c, OID_PKCS1_RSA );
+
+    len += asn1_write_int( &c, 0 );
+
+    len += asn1_write_len( &c, len);
+    len += asn1_write_tag( &c, ASN1_CONSTRUCTED | ASN1_SEQUENCE );*/
+
+/*    for(i = 0; i < len; ++i)
+    {
+        if (i % 16 == 0 ) printf("\n");
+        printf("%02x ", c[i]);
+    }
+    printf("\n");*/
+
+    return( len );
+}
+
+int x509_write_name( unsigned char **p, unsigned char *start, char *oid,
+                     char *name )
+{
+    int ret;
+    size_t string_len = 0;
+    size_t oid_len = 0;
+    size_t len = 0;
+
+    // Write PrintableString
+    //
+    ASN1_CHK_ADD( string_len, asn1_write_printable_string( p, start, name ) );
+
+    // Write OID
+    //
+    ASN1_CHK_ADD( oid_len, asn1_write_oid( p, start, oid ) );
+
+    len = oid_len + string_len;
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, oid_len + string_len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_CONSTRUCTED | ASN1_SET ) );
+
+    return( len );
+}
+
+int x509_write_sig( unsigned char **p, unsigned char *start, char *oid,
+                    unsigned char *sig, size_t size )
+{
+    int ret;
+    size_t len = 0;
+
+    if( *p - start < (int) size + 1 )
+        return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
+
+    len = size;
+    (*p) -= len;
+    memcpy( *p, sig, len );
+
+    *--(*p) = 0;
+    len += 1;
+
+    ASN1_CHK_ADD( len, asn1_write_len( p, start, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( p, start, ASN1_BIT_STRING ) );
+
+    // Write OID
+    //
+    ASN1_CHK_ADD( len, asn1_write_algorithm_identifier( p, start, oid ) );
+
+    return( len );
+}
+
+int x509_write_cert_req( unsigned char *buf, size_t size, rsa_context *rsa,
+                         x509_req_name *req_name )
+{
+    int ret;
+    unsigned char *c, *c2;
+    unsigned char hash[20];
+    unsigned char sig[512];
+    unsigned char tmp_buf[2048];
+    size_t sub_len = 0, pub_len = 0, sig_len = 0;
+    size_t len = 0;
+    x509_req_name *cur = req_name;
+
+    c = tmp_buf + 2048 - 1;
+
+    ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, 0 ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_CONTEXT_SPECIFIC ) );
+
+    ASN1_CHK_ADD( pub_len, asn1_write_mpi( &c, tmp_buf, &rsa->E ) );
+    ASN1_CHK_ADD( pub_len, asn1_write_mpi( &c, tmp_buf, &rsa->N ) );
+
+    ASN1_CHK_ADD( pub_len, asn1_write_len( &c, tmp_buf, pub_len ) );
+    ASN1_CHK_ADD( pub_len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    if( c - tmp_buf < 1 )
+        return( POLARSSL_ERR_ASN1_BUF_TOO_SMALL );
+
+    *--c = 0;
+    pub_len += 1;
+
+    ASN1_CHK_ADD( pub_len, asn1_write_len( &c, tmp_buf, pub_len ) );
+    ASN1_CHK_ADD( pub_len, asn1_write_tag( &c, tmp_buf, ASN1_BIT_STRING ) );
+
+    ASN1_CHK_ADD( pub_len, asn1_write_algorithm_identifier( &c, tmp_buf, OID_PKCS1_RSA ) );
+
+    len += pub_len;
+    ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, pub_len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    while( cur != NULL )
+    {
+        ASN1_CHK_ADD( sub_len, x509_write_name( &c, tmp_buf, cur->oid, cur->name ) );
+        
+        cur = cur->next;
+    }
+
+    len += sub_len;
+    ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, sub_len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    ASN1_CHK_ADD( len, asn1_write_int( &c, tmp_buf, 0 ) );
+
+    ASN1_CHK_ADD( len, asn1_write_len( &c, tmp_buf, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c, tmp_buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+    
+    sha1( c, len, hash );
+    rsa_pkcs1_sign( rsa, NULL, NULL, RSA_PRIVATE, SIG_RSA_SHA1, 0, hash, sig );
+
+    c2 = buf + size - 1;
+    ASN1_CHK_ADD( sig_len, x509_write_sig( &c2, buf, OID_PKCS1_SHA1, sig, rsa->len ) );
+    
+    c2 -= len;
+    memcpy( c2, c, len ); 
+    
+    len += sig_len;
+    ASN1_CHK_ADD( len, asn1_write_len( &c2, buf, len ) );
+    ASN1_CHK_ADD( len, asn1_write_tag( &c2, buf, ASN1_CONSTRUCTED | ASN1_SEQUENCE ) );
+
+    return( len );
+}
+
+#endif