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strongswan-ext/src/libstrongswan/plugins/sha1/sha1_prf.c
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3.7 KiB
C

/*
* 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 "sha1_prf.h"
#include "sha1_hasher.h"
#include <arpa/inet.h>
typedef struct private_sha1_prf_t private_sha1_prf_t;
typedef struct private_sha1_hasher_t private_sha1_hasher_t;
/**
* Private data structure with hasing context.
*/
struct private_sha1_hasher_t {
/**
* Public interface for this hasher.
*/
sha1_hasher_t public;
/*
* State of the hasher. From sha1_hasher.c, do not change it!
*/
u_int32_t state[5];
u_int32_t count[2];
u_int8_t buffer[64];
};
/**
* Private data structure with keyed prf context.
*/
struct private_sha1_prf_t {
/**
* public prf interface
*/
sha1_prf_t public;
/**
* internal used hasher
*/
private_sha1_hasher_t *hasher;
};
/**
* From sha1_hasher.c
*/
extern void SHA1Update(private_sha1_hasher_t* this, u_int8_t *data, u_int32_t len);
/**
* Implementation of prf_t.get_bytes.
*/
static void get_bytes(private_sha1_prf_t *this, chunk_t seed, u_int8_t *bytes)
{
u_int32_t *hash = (u_int32_t*)bytes;
SHA1Update(this->hasher, seed.ptr, seed.len);
hash[0] = htonl(this->hasher->state[0]);
hash[1] = htonl(this->hasher->state[1]);
hash[2] = htonl(this->hasher->state[2]);
hash[3] = htonl(this->hasher->state[3]);
hash[4] = htonl(this->hasher->state[4]);
}
/**
* Implementation of prf_t.get_block_size.
*/
static size_t get_block_size(private_sha1_prf_t *this)
{
return HASH_SIZE_SHA1;
}
/**
* Implementation of prf_t.allocate_bytes.
*/
static void allocate_bytes(private_sha1_prf_t *this, chunk_t seed, chunk_t *chunk)
{
*chunk = chunk_alloc(HASH_SIZE_SHA1);
get_bytes(this, seed, chunk->ptr);
}
/**
* Implementation of prf_t.get_key_size.
*/
static size_t get_key_size(private_sha1_prf_t *this)
{
return sizeof(this->hasher->state);
}
/**
* Implementation of prf_t.set_key.
*/
static void set_key(private_sha1_prf_t *this, chunk_t key)
{
int i, rounds;
u_int32_t *iv = (u_int32_t*)key.ptr;
this->hasher->public.hasher_interface.reset(&this->hasher->public.hasher_interface);
rounds = min(key.len/sizeof(u_int32_t), sizeof(this->hasher->state));
for (i = 0; i < rounds; i++)
{
this->hasher->state[i] ^= htonl(iv[i]);
}
}
/**
* Implementation of prf_t.destroy.
*/
static void destroy(private_sha1_prf_t *this)
{
this->hasher->public.hasher_interface.destroy(&this->hasher->public.hasher_interface);
free(this);
}
/**
* see header
*/
sha1_prf_t *sha1_prf_create(pseudo_random_function_t algo)
{
private_sha1_prf_t *this;
if (algo != PRF_KEYED_SHA1)
{
return NULL;
}
this = malloc_thing(private_sha1_prf_t);
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;
this->hasher = (private_sha1_hasher_t*)sha1_hasher_create(HASH_SHA1);
return &this->public;
}