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/*
* Copyright (C) 2005-2008 Martin Willi
* Copyright (C) 2005 Jan Hutter
* 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 <string.h>
#include <unistd.h>
#include <errno.h>
#include <utils/debug.h>
#include "random_rng.h"
#include "random_plugin.h"
typedef struct private_random_rng_t private_random_rng_t;
/**
* Private data of an random_rng_t object.
*/
struct private_random_rng_t {
/**
* Public random_rng_t interface.
*/
random_rng_t public;
/**
* random device, depends on quality
*/
int fd;
};
METHOD(rng_t, get_bytes, bool,
private_random_rng_t *this, size_t bytes, uint8_t *buffer)
{
size_t done;
ssize_t got;
done = 0;
while (done < bytes)
{
got = read(this->fd, buffer + done, bytes - done);
if (got <= 0)
{
DBG1(DBG_LIB, "reading from random FD %d failed: %s, retrying...",
this->fd, strerror(errno));
sleep(1);
continue;
}
done += got;
}
return TRUE;
}
METHOD(rng_t, allocate_bytes, bool,
private_random_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_random_rng_t *this)
{
free(this);
}
/*
* Described in header.
*/
random_rng_t *random_rng_create(rng_quality_t quality)
{
private_random_rng_t *this;
INIT(this,
.public = {
.rng = {
.get_bytes = _get_bytes,
.allocate_bytes = _allocate_bytes,
.destroy = _destroy,
},
},
);
switch (quality)
{
case RNG_TRUE:
this->fd = random_plugin_get_dev_random();
break;
case RNG_STRONG:
this->fd = random_plugin_get_strong_equals_true() ?
random_plugin_get_dev_random() :
random_plugin_get_dev_urandom();
break;
case RNG_WEAK:
default:
this->fd = random_plugin_get_dev_urandom();
break;
}
return &this->public;
}
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