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/*
* Copyright (C) 2008 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.
*
* $Id$
*/
#include "xcbc_prf.h"
#include "xcbc.h"
typedef struct private_xcbc_prf_t private_xcbc_prf_t;
/**
* Private data of a xcbc_prf_t object.
*/
struct private_xcbc_prf_t {
/**
* Public xcbc_prf_t interface.
*/
xcbc_prf_t public;
/**
* xcbc to use for generation.
*/
xcbc_t *xcbc;
};
/**
* Implementation of prf_t.get_bytes.
*/
static void get_bytes(private_xcbc_prf_t *this, chunk_t seed, u_int8_t *buffer)
{
this->xcbc->get_mac(this->xcbc, seed, buffer);
}
/**
* Implementation of prf_t.allocate_bytes.
*/
static void allocate_bytes(private_xcbc_prf_t *this, chunk_t seed, chunk_t *chunk)
{
if (chunk)
{
*chunk = chunk_alloc(this->xcbc->get_block_size(this->xcbc));
get_bytes(this, seed, chunk->ptr);
}
else
{
get_bytes(this, seed, NULL);
}
}
/**
* Implementation of prf_t.get_block_size.
*/
static size_t get_block_size(private_xcbc_prf_t *this)
{
return this->xcbc->get_block_size(this->xcbc);
}
/**
* Implementation of prf_t.get_block_size.
*/
static size_t get_key_size(private_xcbc_prf_t *this)
{
/* in xcbc, block and key size are always equal */
return this->xcbc->get_block_size(this->xcbc);
}
/**
* Implementation of prf_t.set_key.
*/
static void set_key(private_xcbc_prf_t *this, chunk_t key)
{
this->xcbc->set_key(this->xcbc, key);
}
/**
* Implementation of prf_t.destroy.
*/
static void destroy(private_xcbc_prf_t *this)
{
this->xcbc->destroy(this->xcbc);
free(this);
}
/*
* Described in header.
*/
xcbc_prf_t *xcbc_prf_create(pseudo_random_function_t algo)
{
private_xcbc_prf_t *this;
xcbc_t *xcbc;
switch (algo)
{
case PRF_AES128_XCBC:
xcbc = xcbc_create(ENCR_AES_CBC, 16);
break;
default:
return NULL;
}
if (!xcbc)
{
return NULL;
}
this = malloc_thing(private_xcbc_prf_t);
this->xcbc = xcbc;
this->public.prf_interface.get_bytes = (void (*) (prf_t *,chunk_t,u_int8_t*))get_bytes;
this->public.prf_interface.allocate_bytes = (void (*) (prf_t*,chunk_t,chunk_t*))allocate_bytes;
this->public.prf_interface.get_block_size = (size_t (*) (prf_t*))get_block_size;
this->public.prf_interface.get_key_size = (size_t (*) (prf_t*))get_key_size;
this->public.prf_interface.set_key = (void (*) (prf_t *,chunk_t))set_key;
this->public.prf_interface.destroy = (void (*) (prf_t *))destroy;
return &this->public;
}
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