diff --git a/skeletons/der_encoder.h b/skeletons/der_encoder.h
new file mode 100644
index 0000000..052d9f4
--- /dev/null
+++ b/skeletons/der_encoder.h
@@ -0,0 +1,73 @@
+/*-
+ * Copyright (c) 2003, 2004 Lev Walkin <vlm@lionet.info>. All rights reserved.
+ * Redistribution and modifications are permitted subject to BSD license.
+ */
+#ifndef	_DER_ENCODER_H_
+#define	_DER_ENCODER_H_
+
+#include <constr_TYPE.h>
+
+struct asn1_TYPE_descriptor_s;	/* Forward declaration */
+
+/*
+ * Type of the return value of the der_encode function.
+ */
+typedef struct der_enc_rval_s {
+	/*
+	 * Number of bytes encoded.
+	 * -1 indicates failure to encode the structure.
+	 * In this case, the members below this one are meaningful.
+	 */
+	ssize_t encoded;
+
+	/*
+	 * Members meaningful when (encoded == -1), for post-mortem analysis.
+	 */
+
+	/* Type which cannot be encoded */
+	struct asn1_TYPE_descriptor_s *failed_type;
+
+	/* Pointer to the structure of that type */
+	void *structure_ptr;
+} der_enc_rval_t;
+
+
+/*
+ * The DER encoder of any type. May be invoked by the application.
+ */
+der_enc_rval_t der_encode(struct asn1_TYPE_descriptor_s *type_descriptor,
+		void *struct_ptr,	/* Structure to be encoded */
+		asn_app_consume_bytes_f *consume_bytes_cb,
+		void *app_key		/* Arbitrary callback argument */
+	);
+
+/*
+ * Type of the generic DER encoder.
+ */
+typedef der_enc_rval_t (der_type_encoder_f)(
+		struct asn1_TYPE_descriptor_s *type_descriptor,
+		void *struct_ptr,	/* Structure to be encoded */
+		int tag_mode,		/* {-1,0,1}: IMPLICIT, no, EXPLICIT */
+		ber_tlv_tag_t tag,
+		asn_app_consume_bytes_f *consume_bytes_cb,	/* Callback */
+		void *app_key		/* Arbitrary callback argument */
+	);
+
+
+/*******************************
+ * INTERNALLY USEFUL FUNCTIONS *
+ *******************************/
+
+/*
+ * Write out leading TL[v] sequence according to the type definition.
+ */
+ssize_t der_write_tags(
+		struct asn1_TYPE_descriptor_s *type_descriptor,
+		size_t struct_length,
+		int tag_mode,		/* {-1,0,1}: IMPLICIT, no, EXPLICIT */
+		ber_tlv_tag_t tag,
+		asn_app_consume_bytes_f *consume_bytes_cb,
+		void *app_key
+	);
+
+#endif	/* _DER_ENCODER_H_ */