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/*
* �Anytun
*
* �Anytun is a tiny implementation of SATP. Unlike Anytun which is a full
* featured implementation �Anytun has no support for multiple connections
* or synchronisation. It is a small single threaded implementation intended
* to act as a client on small platforms.
* The secure anycast tunneling protocol (satp) defines a protocol used
* for communication between any combination of unicast and anycast
* tunnel endpoints. It has less protocol overhead than IPSec in Tunnel
* mode and allows tunneling of every ETHER TYPE protocol (e.g.
* ethernet, ip, arp ...). satp directly includes cryptography and
* message authentication based on the methodes used by SRTP. It is
* intended to deliver a generic, scaleable and secure solution for
* tunneling and relaying of packets of any protocol.
*
*
* Copyright (C) 2007-2008 Christian Pointner <equinox@anytun.org>
*
* This file is part of �Anytun.
*
* �Anytun is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 3 as
* published by the Free Software Foundation.
*
* �Anytun 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.
*
* You should have received a copy of the GNU General Public License
* along with �Anytun. If not, see <http://www.gnu.org/licenses/>.
*/
#include "datatypes.h"
#include "plain_packet.h"
#include "encrypted_packet.h"
#include "cipher.h"
#include "log.h"
#include <stdlib.h>
#include <string.h>
void cipher_init(cipher_t** c, const char* type)
{
if(!c)
return;
*c = malloc(sizeof(cipher_t));
if(!*c)
return;
(*c)->type_ = unknown;
if(!strcmp(type, "null"))
(*c)->type_ = null;
else if(!strcmp(type, "aes-ctr"))
(*c)->type_ = aes_ctr;
else {
log_printf(ERR, "unknown cipher type");
}
(*c)->key_.buf_ = NULL;
(*c)->key_.length_ = 0;
(*c)->salt_.buf_ = NULL;
(*c)->salt_.length_ = 0;
}
void cipher_set_key(cipher_t* c, u_int8_t* key, u_int32_t len)
{
if(!c)
return;
if(c->type_ == null)
return;
if(c->key_.buf_)
free(c->key_.buf_);
c->key_.buf_ = malloc(len);
if(!c->key_.buf_) {
c->key_.length_ = 0;
return;
}
memcpy(c->key_.buf_, key, len);
c->key_.length_ = len;
}
void cipher_set_salt(cipher_t* c, u_int8_t* salt, u_int32_t len)
{
if(!c)
return;
if(c->type_ == null)
return;
if(c->salt_.buf_)
free(c->salt_.buf_);
c->salt_.buf_ = malloc(len);
if(!c->salt_.buf_) {
c->salt_.length_ = 0;
return;
}
memcpy(c->salt_.buf_, salt, len);
c->salt_.length_ = len;
}
void cipher_close(cipher_t** c)
{
if(!c || !(*c))
return;
if((*c)->key_.buf_)
free((*c)->key_.buf_);
if((*c)->salt_.buf_)
free((*c)->salt_.buf_);
free(*c);
*c = NULL;
}
void cipher_encrypt(cipher_t* c, plain_packet_t* in, encrypted_packet_t* out, seq_nr_t seq_nr, sender_id_t sender_id, mux_t mux)
{
if(!c)
return;
u_int32_t len;
if(c->type_ = null)
len = cipher_null_encrypt(plain_packet_get_packet(in), plain_packet_get_length(in),
encrypted_packet_get_payload(out), encrypted_packet_get_payload_length(out));
else if(c->type_ = aes_ctr)
len = cipher_aesctr_encrypt(plain_packet_get_packet(in), plain_packet_get_length(in),
encrypted_packet_get_payload(out), encrypted_packet_get_payload_length(out),
seq_nr, sender_id, mux);
else {
log_printf(ERR, "unknown cipher type");
return;
}
encrypted_packet_set_sender_id(out, sender_id);
encrypted_packet_set_seq_nr(out, seq_nr);
encrypted_packet_set_mux(out, mux);
encrypted_packet_set_payload_length(out, len);
}
void cipher_decrypt(cipher_t* c, encrypted_packet_t* in, plain_packet_t* out)
{
if(!c)
return;
u_int32_t len;
if(c->type_ = null)
len = cipher_null_decrypt(encrypted_packet_get_payload(in), encrypted_packet_get_payload_length(in),
plain_packet_get_packet(out), plain_packet_get_length(out));
else if(c->type_ = aes_ctr)
len = cipher_aesctr_decrypt(encrypted_packet_get_payload(in), encrypted_packet_get_payload_length(in),
plain_packet_get_packet(out), plain_packet_get_length(out),
encrypted_packet_get_seq_nr(in), encrypted_packet_get_sender_id(in),
encrypted_packet_get_mux(in));
else {
log_printf(ERR, "unknown cipher type");
return;
}
plain_packet_set_length(out, len);
}
u_int32_t cipher_null_encrypt(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen)
{
memcpy(out, in, (ilen < olen) ? ilen : olen);
return (ilen < olen) ? ilen : olen;
}
u_int32_t cipher_null_decrypt(u_int8_t* in, u_int32_t ilen, u_int8_t* out, u_int32_t olen)
{
memcpy(out, in, (ilen < olen) ? ilen : olen);
return (ilen < olen) ? ilen : olen;
}
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