diff --git a/src/cw/dtls_common.h b/src/cw/dtls_common.h
new file mode 100644
index 00000000..ae268368
--- /dev/null
+++ b/src/cw/dtls_common.h
@@ -0,0 +1,13 @@
+#include <stdint.h>
+#include "conn.h"
+struct dtls_ssl_cert 
+{
+	int size;
+	int type;
+	uint8_t * data;
+};
+
+extern int dtls_bio_read(struct conn *conn, char *out, int maxlen);
+extern int dtls_bio_write(struct conn * conn, const char *data, int len);
+
+