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Diffstat (limited to 'src/libstrongswan/plugins/bliss/bliss_sampler.h')
-rw-r--r-- | src/libstrongswan/plugins/bliss/bliss_sampler.h | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/bliss/bliss_sampler.h b/src/libstrongswan/plugins/bliss/bliss_sampler.h new file mode 100644 index 000000000..2c75d4480 --- /dev/null +++ b/src/libstrongswan/plugins/bliss/bliss_sampler.h @@ -0,0 +1,94 @@ +/* + * 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_ @}*/ |