diff --git a/include/polarssl/x509write.h b/include/polarssl/x509write.h
new file mode 100644
index 0000000..c24f3e1
--- /dev/null
+++ b/include/polarssl/x509write.h
@@ -0,0 +1,46 @@
+/**
+ * \file x509write.h
+ *
+ * \brief 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.
+ */
+#ifndef POLARSSL_X509_WRITE_H
+#define POLARSSL_X509_WRITE_H
+
+#include "rsa.h"
+
+typedef struct _x509_req_name
+{
+    char oid[128];
+    char name[128];
+
+    struct _x509_req_name *next;
+}
+x509_req_name;
+
+int x509_write_pubkey_der( unsigned char *buf, size_t size, rsa_context *rsa );
+int x509_write_key_der( unsigned char *buf, size_t size, rsa_context *rsa );
+int x509_write_cert_req( unsigned char *buf, size_t size, rsa_context *rsa,
+                         x509_req_name *req_name );
+
+#endif /* POLARSSL_X509_WRITE_H */