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/*
* Copyright (C) 2005-2006 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 <stddef.h>
#include "ke_payload.h"
#include <encoding/payloads/encodings.h>
typedef struct private_ke_payload_t private_ke_payload_t;
/**
* Private data of an ke_payload_t object.
*
*/
struct private_ke_payload_t {
/**
* Public ke_payload_t interface.
*/
ke_payload_t public;
/**
* Next payload type.
*/
u_int8_t next_payload;
/**
* Critical flag.
*/
bool critical;
/**
* Length of this payload.
*/
u_int16_t payload_length;
/**
* DH Group Number.
*/
u_int16_t dh_group_number;
/**
* Key Exchange Data of this KE payload.
*/
chunk_t key_exchange_data;
};
/**
* Encoding rules to parse or generate a IKEv2-KE Payload.
*
* The defined offsets are the positions in a object of type
* private_ke_payload_t.
*
*/
encoding_rule_t ke_payload_encodings[] = {
/* 1 Byte next payload type, stored in the field next_payload */
{ U_INT_8, offsetof(private_ke_payload_t, next_payload) },
/* the critical bit */
{ FLAG, offsetof(private_ke_payload_t, critical) },
/* 7 Bit reserved bits, nowhere stored */
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
{ RESERVED_BIT, 0 },
/* Length of the whole payload*/
{ PAYLOAD_LENGTH, offsetof(private_ke_payload_t, payload_length) },
/* DH Group number as 16 bit field*/
{ U_INT_16, offsetof(private_ke_payload_t, dh_group_number) },
{ RESERVED_BYTE, 0 },
{ RESERVED_BYTE, 0 },
/* Key Exchange Data is from variable size */
{ KEY_EXCHANGE_DATA, offsetof(private_ke_payload_t, key_exchange_data)}
};
/*
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Next Payload !C! RESERVED ! Payload Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! DH Group # ! RESERVED !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! !
~ Key Exchange Data ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/**
* Implementation of payload_t.verify.
*/
static status_t verify(private_ke_payload_t *this)
{
/* dh group is not verified in here */
return SUCCESS;
}
/**
* Implementation of payload_t.destroy.
*/
static void destroy(private_ke_payload_t *this)
{
if (this->key_exchange_data.ptr != NULL)
{
free(this->key_exchange_data.ptr);
}
free(this);
}
/**
* Implementation of payload_t.get_encoding_rules.
*/
static void get_encoding_rules(private_ke_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
{
*rules = ke_payload_encodings;
*rule_count = sizeof(ke_payload_encodings) / sizeof(encoding_rule_t);
}
/**
* Implementation of payload_t.get_type.
*/
static payload_type_t get_type(private_ke_payload_t *this)
{
return KEY_EXCHANGE;
}
/**
* Implementation of payload_t.get_next_type.
*/
static payload_type_t get_next_type(private_ke_payload_t *this)
{
return (this->next_payload);
}
/**
* Implementation of payload_t.set_next_type.
*/
static void set_next_type(private_ke_payload_t *this,payload_type_t type)
{
this->next_payload = type;
}
/**
* recompute the length of the payload.
*/
static void compute_length(private_ke_payload_t *this)
{
size_t length = KE_PAYLOAD_HEADER_LENGTH;
if (this->key_exchange_data.ptr != NULL)
{
length += this->key_exchange_data.len;
}
this->payload_length = length;
}
/**
* Implementation of payload_t.get_length.
*/
static size_t get_length(private_ke_payload_t *this)
{
compute_length(this);
return this->payload_length;
}
/**
* Implementation of ke_payload_t.get_key_exchange_data.
*/
static chunk_t get_key_exchange_data(private_ke_payload_t *this)
{
return (this->key_exchange_data);
}
/**
* Implementation of ke_payload_t.set_key_exchange_data.
*/
static void set_key_exchange_data(private_ke_payload_t *this, chunk_t key_exchange_data)
{
/* destroy existing data first */
if (this->key_exchange_data.ptr != NULL)
{
/* free existing value */
free(this->key_exchange_data.ptr);
this->key_exchange_data.ptr = NULL;
this->key_exchange_data.len = 0;
}
this->key_exchange_data = chunk_clone(key_exchange_data);
compute_length(this);
}
/**
* Implementation of ke_payload_t.get_dh_group_number.
*/
static diffie_hellman_group_t get_dh_group_number(private_ke_payload_t *this)
{
return this->dh_group_number;
}
/**
* Implementation of ke_payload_t.set_dh_group_number.
*/
static void set_dh_group_number(private_ke_payload_t *this, diffie_hellman_group_t dh_group_number)
{
this->dh_group_number = dh_group_number;
}
/*
* Described in header
*/
ke_payload_t *ke_payload_create()
{
private_ke_payload_t *this = malloc_thing(private_ke_payload_t);
/* interface functions */
this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules;
this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length;
this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type;
this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type;
this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type;
this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
/* public functions */
this->public.get_key_exchange_data = (chunk_t (*) (ke_payload_t *)) get_key_exchange_data;
this->public.set_key_exchange_data = (void (*) (ke_payload_t *,chunk_t)) set_key_exchange_data;
this->public.get_dh_group_number = (diffie_hellman_group_t (*) (ke_payload_t *)) get_dh_group_number;
this->public.set_dh_group_number =(void (*) (ke_payload_t *,diffie_hellman_group_t)) set_dh_group_number;
this->public.destroy = (void (*) (ke_payload_t *)) destroy;
/* set default values of the fields */
this->critical = FALSE;
this->next_payload = NO_PAYLOAD;
this->payload_length = KE_PAYLOAD_HEADER_LENGTH;
this->key_exchange_data = chunk_empty;
this->dh_group_number = MODP_NONE;
return &this->public;
}
/*
* Described in header
*/
ke_payload_t *ke_payload_create_from_diffie_hellman(diffie_hellman_t *dh)
{
private_ke_payload_t *this = (private_ke_payload_t*)ke_payload_create();
dh->get_my_public_value(dh, &this->key_exchange_data);
this->dh_group_number = dh->get_dh_group(dh);
compute_length(this);
return &this->public;
}
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