Implemented ntru_private_key class

src/libstrongswan/plugins/ntru/ntru_public_key.c

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2014 Andreas Steffen
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * Copyright (C) 2009-2013  Security Innovation
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "ntru_public_key.h"
+
+#include "ntru_crypto/ntru_crypto_ntru_convert.h"
+
+#include <utils/debug.h>
+
+typedef struct private_ntru_public_key_t private_ntru_public_key_t;
+
+/**
+ * Private data of an ntru_public_key_t object.
+ */
+struct private_ntru_public_key_t {
+	/**
+	 * Public ntru_public_key_t interface.
+	 */
+	ntru_public_key_t public;
+
+	/**
+	 * NTRU Parameter Set
+	 */
+	ntru_param_set_t *params;
+
+	/**
+	 * Polynomial h which is the public key
+	 */
+	uint16_t *pubkey;
+
+	/**
+	 * Encoding of the public key
+	 */
+	chunk_t encoding;
+
+};
+
+METHOD(ntru_public_key_t, get_encoding, chunk_t,
+	private_ntru_public_key_t *this)
+{
+	if (!this->encoding.len)
+	{
+		size_t pubkey_len;
+		u_char *enc;
+
+		/* compute public key length encoded as packed coefficients */
+		pubkey_len =  (this->params->N * this->params->q_bits + 7) / 8;
+
+		/* allocate memory for public key encoding */
+		this->encoding = chunk_alloc(2 + NTRU_OID_LEN + pubkey_len);
+		enc = this->encoding.ptr;
+
+		/* format header and packed public key */
+		*enc++ = NTRU_PUBKEY_TAG;
+		*enc++ = NTRU_OID_LEN;
+		memcpy(enc, this->params->oid, NTRU_OID_LEN);
+		enc += NTRU_OID_LEN;
+		ntru_elements_2_octets(this->params->N, this->pubkey,
+							   this->params->q_bits, enc);
+	}
+	return this->encoding;
+}
+
+METHOD(ntru_public_key_t, destroy, void,
+	private_ntru_public_key_t *this)
+{
+	chunk_clear(&this->encoding);
+	free(this->pubkey);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+ntru_public_key_t *ntru_public_key_create(ntru_param_set_t *params,
+										  uint16_t *pubkey)
+{
+	private_ntru_public_key_t *this;
+	int i;
+
+	INIT(this,
+		.public = {
+			.get_encoding = _get_encoding,
+			.destroy = _destroy,
+		},
+		.params = params,
+		.pubkey = malloc(params->N * sizeof(uint16_t)),
+	);
+
+	for (i = 0; i < params->N; i++)
+	{
+		this->pubkey[i] = pubkey[i];
+	}
+
+	return &this->public;
+}