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/*
* Copyright (C) 2009 Martin Willi
* 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.
*/
#include "gcrypt_rng.h"
#include <gcrypt.h>
typedef struct private_gcrypt_rng_t private_gcrypt_rng_t;
/**
* Private data of an gcrypt_rng_t object.
*/
struct private_gcrypt_rng_t {
/**
* Public gcrypt_rng_t interface.
*/
gcrypt_rng_t public;
/**
* RNG quality of this instance
*/
rng_quality_t quality;
};
METHOD(rng_t, get_bytes, bool,
private_gcrypt_rng_t *this, size_t bytes, uint8_t *buffer)
{
switch (this->quality)
{
case RNG_WEAK:
gcry_create_nonce(buffer, bytes);
break;
case RNG_STRONG:
gcry_randomize(buffer, bytes, GCRY_STRONG_RANDOM);
break;
case RNG_TRUE:
gcry_randomize(buffer, bytes, GCRY_VERY_STRONG_RANDOM);
break;
}
return TRUE;
}
METHOD(rng_t, allocate_bytes, bool,
private_gcrypt_rng_t *this, size_t bytes, chunk_t *chunk)
{
*chunk = chunk_alloc(bytes);
get_bytes(this, chunk->len, chunk->ptr);
return TRUE;
}
METHOD(rng_t, destroy, void,
private_gcrypt_rng_t *this)
{
free(this);
}
/*
* Described in header.
*/
gcrypt_rng_t *gcrypt_rng_create(rng_quality_t quality)
{
private_gcrypt_rng_t *this;
switch (quality)
{
case RNG_WEAK:
case RNG_STRONG:
case RNG_TRUE:
break;
default:
return NULL;
}
INIT(this,
.public = {
.rng = {
.get_bytes = _get_bytes,
.allocate_bytes = _allocate_bytes,
.destroy = _destroy,
},
},
.quality = quality,
);
return &this->public;
}
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