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+/*
+ * Copyright (C) 2014 Andreas Steffen
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup bliss_sampler bliss_sampler
+ * @{ @ingroup bliss_p
+ */
+
+#ifndef BLISS_SAMPLER_H_
+#define BLISS_SAMPLER_H_
+
+typedef struct bliss_sampler_t bliss_sampler_t;
+
+#include "bliss_param_set.h"
+
+#include <library.h>
+#include <crypto/hashers/hasher.h>
+
+/**
+ * Implementation various rejection sampling algorithms.
+ */
+struct bliss_sampler_t {
+
+ /**
+ * Sample according to exp(-x/(2*sigma^2))
+ *
+ * @param x Value to be sampled
+ * @param accepted TRUE if value is accepted, FALSE if rejected
+ * @result TRUE if sampling was successful
+ */
+ bool (*bernoulli_exp)(bliss_sampler_t *this, uint32_t x, bool *accepted);
+
+ /**
+ * Sample according to 1/cosh(x/sigma^2)
+ *
+ * @param x Value to be sampled
+ * @param accepted TRUE if value is accepted, FALSE if rejected
+ * @result TRUE if sampling was successful
+ */
+ bool (*bernoulli_cosh)(bliss_sampler_t *this, int32_t x, bool *accepted);
+
+ /**
+ * Sample according to 2^(-x^2) for positive x
+ *
+ * @param x Generated value
+ * @result TRUE if sampling was successful
+ */
+ bool (*pos_binary)(bliss_sampler_t *this, uint32_t *x);
+
+ /**
+ * Sample according to the Gaussian distribution exp(-x^2/(2*sigma^2))
+ *
+ * @param z Generated value with Gaussian distribution
+ * @result TRUE if sampling was successful
+ */
+ bool (*gaussian)(bliss_sampler_t *this, int32_t *z);
+
+ /**
+ * Sample the sign according to the binary distribution
+ *
+ * @param positive TRUE if positive
+ * @result TRUE if sampling was successful
+ */
+ bool (*sign)(bliss_sampler_t *this, bool *positive);
+
+ /**
+ * Destroy bliss_sampler_t object
+ */
+ void (*destroy)(bliss_sampler_t *this);
+};
+
+/**
+ * Create a bliss_sampler_t object.
+ *
+ * @param alg Hash algorithm to be used for the internal bitspender
+ * @param seed Seed used to initialize the internal bitspender
+ * @param set BLISS parameter set to be used
+ */
+bliss_sampler_t *bliss_sampler_create(hash_algorithm_t alg, chunk_t seed,
+ bliss_param_set_t *set);
+
+#endif /** BLISS_SAMPLER_H_ @}*/