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/*
* Copyright (C) 2009 Martin Willi
* 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;
};
/**
* Implementation of gcrypt_rng_t.get_bytes.
*/
static void get_bytes(private_gcrypt_rng_t *this, size_t bytes,
u_int8_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;
}
}
/**
* Implementation of gcrypt_rng_t.allocate_bytes.
*/
static void allocate_bytes(private_gcrypt_rng_t *this, size_t bytes,
chunk_t *chunk)
{
*chunk = chunk_alloc(bytes);
get_bytes(this, chunk->len, chunk->ptr);
}
/**
* Implementation of gcrypt_rng_t.destroy.
*/
static void destroy(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;
}
this = malloc_thing(private_gcrypt_rng_t);
this->public.rng.get_bytes = (void (*) (rng_t *, size_t, u_int8_t*)) get_bytes;
this->public.rng.allocate_bytes = (void (*) (rng_t *, size_t, chunk_t*)) allocate_bytes;
this->public.rng.destroy = (void (*) (rng_t *))destroy;
this->quality = quality;
return &this->public;
}
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