strongswan/Source/charon/encoding/payloads/ke_payload.c

320 lines
8.9 KiB
C

/**
* @file ke_payload.c
*
* @brief Declaration of the class ke_payload_t.
*
* An object of this type represents an IKEv2 KE-Payload.
*
* See section 3.4 of RFC for details of this payload type.
*
*/
/*
* Copyright (C) 2005 Jan Hutter, 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.
*/
/* offsetof macro */
#include <stddef.h>
#include "ke_payload.h"
#include <encoding/payloads/encodings.h>
#include <utils/allocator.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
*/
diffie_hellman_group_t dh_group_number;
/**
* Key Exchange Data of this KE payload
*/
chunk_t key_exchange_data;
/**
* @brief Computes the length of this payload.
*
* @param this calling private_ke_payload_t object
* @return
* SUCCESS in any case
*/
status_t (*compute_length) (private_ke_payload_t *this);
};
/**
* 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 ~
! !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/**
* Implements payload_t's verify function.
* See #payload_s.verify for description.
*/
static status_t verify(private_ke_payload_t *this)
{
if (this->critical)
{
/* critical bit is set! */
return FAILED;
}
/* dh group is not verified in here */
return SUCCESS;
}
/**
* Implements payload_t's and ke_payload_t's destroy function.
* See #payload_s.destroy or ke_payload_s.destroy for description.
*/
static status_t destroy(private_ke_payload_t *this)
{
if (this->key_exchange_data.ptr != NULL)
{
allocator_free(this->key_exchange_data.ptr);
}
allocator_free(this);
return SUCCESS;
}
/**
* Implements payload_t's get_encoding_rules function.
* See #payload_s.get_encoding_rules for description.
*/
static status_t 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);
return SUCCESS;
}
/**
* Implements payload_t's get_type function.
* See #payload_s.get_type for description.
*/
static payload_type_t get_type(private_ke_payload_t *this)
{
return KEY_EXCHANGE;
}
/**
* Implements payload_t's get_next_type function.
* See #payload_s.get_next_type for description.
*/
static payload_type_t get_next_type(private_ke_payload_t *this)
{
return (this->next_payload);
}
/**
* Implements payload_t's set_next_type function.
* See #payload_s.set_next_type for description.
*/
static status_t set_next_type(private_ke_payload_t *this,payload_type_t type)
{
this->next_payload = type;
return SUCCESS;
}
/**
* Implements payload_t's get_length function.
* See #payload_s.get_length for description.
*/
static size_t get_length(private_ke_payload_t *this)
{
this->compute_length(this);
return this->payload_length;
}
/**
* Implements private_ke_payload_t's compute_length function.
* See #private_ke_payload_s.compute_length for description.
*/
static status_t 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;
return SUCCESS;
}
/**
* Implements ke_payload_t's get_key_exchange_data function.
* See #ke_payload_t.get_key_exchange_data for description.
*/
chunk_t get_key_exchange_data(private_ke_payload_t *this)
{
return (this->key_exchange_data);
}
/**
* Implements ke_payload_t's set_key_exchange_data function.
* See #ke_payload_t.set_key_exchange_data for description.
*/
status_t 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 */
allocator_free(this->key_exchange_data.ptr);
this->key_exchange_data.ptr = NULL;
this->key_exchange_data.len = 0;
}
this->key_exchange_data.ptr = allocator_clone_bytes(key_exchange_data.ptr,key_exchange_data.len);
if (this->key_exchange_data.ptr == NULL)
{
return OUT_OF_RES;
}
this->key_exchange_data.len = key_exchange_data.len;
this->compute_length(this);
return SUCCESS;
}
/**
* Implements ke_payload_t's get_dh_group_number function.
* See #ke_payload_t.get_dh_group_number for description.
*/
diffie_hellman_group_t get_dh_group_number(private_ke_payload_t *this)
{
return this->dh_group_number;
}
/**
* Implements ke_payload_t's set_dh_group_number function.
* See #ke_payload_t.set_dh_group_number for description.
*/
status_t set_dh_group_number(private_ke_payload_t *this, diffie_hellman_group_t dh_group_number)
{
this->dh_group_number = dh_group_number;
return SUCCESS;
}
/*
* Described in header
*/
ke_payload_t *ke_payload_create()
{
private_ke_payload_t *this = allocator_alloc_thing(private_ke_payload_t);
if (this == NULL)
{
return NULL;
}
/* interface functions */
this->public.payload_interface.verify = (status_t (*) (payload_t *))verify;
this->public.payload_interface.get_encoding_rules = (status_t (*) (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 = (status_t (*) (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 = (status_t (*) (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 = (status_t (*) (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 =(status_t (*) (ke_payload_t *,diffie_hellman_group_t)) set_dh_group_number;
this->public.destroy = (status_t (*) (ke_payload_t *)) destroy;
/* private functions */
this->compute_length = compute_length;
/* set default values of the fields */
this->critical = KE_PAYLOAD_CRITICAL_FLAG;
this->next_payload = NO_PAYLOAD;
this->payload_length = KE_PAYLOAD_HEADER_LENGTH;
this->key_exchange_data.ptr = NULL;
this->key_exchange_data.len = 0;
this->dh_group_number = 0;
return (&(this->public));
}