Added a sample that fixes comment two on issue #1264.

samples/C/ntru_encrypt.h

@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2014 FH Bielefeld
+ *
+ * This file is part of a FH Bielefeld project.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA  02110-1301  USA
+ */
+
+/**
+ * @file ntru_encrypt.h
+ * Header for the internal API of ntru_encrypt.c.
+ * @brief header for encrypt.c
+ */
+
+#ifndef PQC_ENCRYPT_H
+#define PQC_ENCRYPT_H
+
+
+#include "ntru_params.h"
+#include "ntru_poly.h"
+#include "ntru_string.h"
+
+#include <fmpz_poly.h>
+#include <fmpz.h>
+
+
+/**
+ * encrypt the msg, using the math:
+ * e = (h ∗ r) + m (mod q)
+ *
+ * e = the encrypted poly
+ *
+ * h = the public key
+ *
+ * r = the random poly
+ *
+ * m = the message poly
+ *
+ * q = large mod
+ *
+ * @param msg_tern the message to encrypt, in ternary format
+ * @param pub_key the public key
+ * @param rnd the random poly (should have relatively small
+ * coefficients, but not restricted to {-1, 0, 1})
+ * @param out the output poly which is in the range {0, q-1}
+ * (not ternary!) [out]
+ * @param params ntru_params the ntru context
+ */
+void
+ntru_encrypt_poly(
+		const fmpz_poly_t msg_tern,
+		const fmpz_poly_t pub_key,
+		const fmpz_poly_t rnd,
+		fmpz_poly_t out,
+		const ntru_params *params);
+
+/**
+ * Encrypt a message in the form of a null-terminated char array and
+ * return a string.
+ *
+ * @param msg the message
+ * @param pub_key the public key
+ * @param rnd the random poly (should have relatively small
+ * coefficients, but not restricted to {-1, 0, 1})
+ * @param params ntru_params the ntru context
+ * @return the newly allocated encrypted string
+ */
+string *
+ntru_encrypt_string(
+		const string *msg,
+		const fmpz_poly_t pub_key,
+		const fmpz_poly_t rnd,
+		const ntru_params *params);
+
+
+#endif /* PQC_ENCRYPT_H */