strongswan/src/libcharon/encoding/payloads/eap_payload.c

327 lines
7.1 KiB
C

/*
* Copyright (C) 2005-2010 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 "eap_payload.h"
#include <daemon.h>
typedef struct private_eap_payload_t private_eap_payload_t;
/**
* Private data of an eap_payload_t object.
*
*/
struct private_eap_payload_t {
/**
* Public eap_payload_t interface.
*/
eap_payload_t public;
/**
* Next payload type.
*/
u_int8_t next_payload;
/**
* Critical flag.
*/
bool critical;
/**
* Reserved bits
*/
bool reserved[7];
/**
* Length of this payload.
*/
u_int16_t payload_length;
/**
* EAP message data, if available
*/
chunk_t data;
};
/**
* Encoding rules to parse or generate a EAP payload.
*
* The defined offsets are the positions in a object of type
* private_eap_payload_t.
*
*/
static encoding_rule_t encodings[] = {
/* 1 Byte next payload type, stored in the field next_payload */
{ U_INT_8, offsetof(private_eap_payload_t, next_payload) },
/* the critical bit */
{ FLAG, offsetof(private_eap_payload_t, critical) },
/* 7 Bit reserved bits, nowhere stored */
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[0]) },
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[1]) },
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[2]) },
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[3]) },
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[4]) },
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[5]) },
{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[6]) },
/* Length of the whole payload*/
{ PAYLOAD_LENGTH, offsetof(private_eap_payload_t, payload_length) },
/* chunt to data, starting at "code" */
{ CHUNK_DATA, offsetof(private_eap_payload_t, 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 !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Code ! Identifier ! Length !
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
! Type ! Type_Data...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
*/
METHOD(payload_t, verify, status_t,
private_eap_payload_t *this)
{
u_int16_t length;
u_int8_t code;
if (this->data.len < 4)
{
DBG1(DBG_ENC, "EAP payloads EAP message too short (%d)", this->data.len);
return FAILED;
}
length = untoh16(this->data.ptr + 2);
if (this->data.len != length)
{
DBG1(DBG_ENC, "EAP payload length (%d) does not match contained "
"message length (%d)", this->data.len, length);
return FAILED;
}
code = this->data.ptr[0];
switch (code)
{
case EAP_REQUEST:
case EAP_RESPONSE:
{
if (this->data.len < 4)
{
DBG1(DBG_ENC, "EAP Request/Response does not have any data");
return FAILED;
}
break;
}
case EAP_SUCCESS:
case EAP_FAILURE:
{
if (this->data.len != 4)
{
DBG1(DBG_ENC, "EAP Success/Failure has data");
return FAILED;
}
break;
}
default:
return FAILED;
}
return SUCCESS;
}
METHOD(payload_t, get_encoding_rules, int,
private_eap_payload_t *this, encoding_rule_t **rules)
{
*rules = encodings;
return countof(encodings);
}
METHOD(payload_t, get_header_length, int,
private_eap_payload_t *this)
{
return 4;
}
METHOD(payload_t, get_payload_type, payload_type_t,
private_eap_payload_t *this)
{
return EXTENSIBLE_AUTHENTICATION;
}
METHOD(payload_t, get_next_type, payload_type_t,
private_eap_payload_t *this)
{
return (this->next_payload);
}
METHOD(payload_t, set_next_type, void,
private_eap_payload_t *this, payload_type_t type)
{
this->next_payload = type;
}
METHOD(payload_t, get_length, size_t,
private_eap_payload_t *this)
{
return this->payload_length;
}
METHOD(eap_payload_t, get_data, chunk_t,
private_eap_payload_t *this)
{
return this->data;
}
METHOD(eap_payload_t, set_data, void,
private_eap_payload_t *this, chunk_t data)
{
free(this->data.ptr);
this->data = chunk_clone(data);
this->payload_length = this->data.len + 4;
}
METHOD(eap_payload_t, get_code, eap_code_t,
private_eap_payload_t *this)
{
if (this->data.len > 0)
{
return this->data.ptr[0];
}
/* should not happen, as it is verified */
return 0;
}
METHOD(eap_payload_t, get_identifier, u_int8_t,
private_eap_payload_t *this)
{
if (this->data.len > 1)
{
return this->data.ptr[1];
}
/* should not happen, as it is verified */
return 0;
}
METHOD(eap_payload_t, get_type, eap_type_t,
private_eap_payload_t *this, u_int32_t *vendor)
{
eap_type_t type;
*vendor = 0;
if (this->data.len > 4)
{
type = this->data.ptr[4];
if (type != EAP_EXPANDED)
{
return type;
}
if (this->data.len >= 12)
{
*vendor = untoh32(this->data.ptr + 4) & 0x00FFFFFF;
return untoh32(this->data.ptr + 8);
}
}
return 0;
}
METHOD2(payload_t, eap_payload_t, destroy, void,
private_eap_payload_t *this)
{
chunk_free(&this->data);
free(this);
}
/*
* Described in header
*/
eap_payload_t *eap_payload_create()
{
private_eap_payload_t *this;
INIT(this,
.public = {
.payload_interface = {
.verify = _verify,
.get_encoding_rules = _get_encoding_rules,
.get_header_length = _get_header_length,
.get_length = _get_length,
.get_next_type = _get_next_type,
.set_next_type = _set_next_type,
.get_type = _get_payload_type,
.destroy = _destroy,
},
.get_data = _get_data,
.set_data = _set_data,
.get_code = _get_code,
.get_identifier = _get_identifier,
.get_type = _get_type,
.destroy = _destroy,
},
.next_payload = NO_PAYLOAD,
.payload_length = get_header_length(this),
);
return &this->public;
}
/*
* Described in header
*/
eap_payload_t *eap_payload_create_data(chunk_t data)
{
eap_payload_t *this = eap_payload_create();
this->set_data(this, data);
return this;
}
/*
* Described in header
*/
eap_payload_t *eap_payload_create_data_own(chunk_t data)
{
eap_payload_t *this = eap_payload_create();
this->set_data(this, data);
free(data.ptr);
return this;
}
/*
* Described in header
*/
eap_payload_t *eap_payload_create_code(eap_code_t code, u_int8_t identifier)
{
chunk_t data;
data = chunk_from_chars(code, identifier, 0, 0);
htoun16(data.ptr + 2, data.len);
return eap_payload_create_data(data);
}
/*
* Described in header
*/
eap_payload_t *eap_payload_create_nak(u_int8_t identifier)
{
chunk_t data;
data = chunk_from_chars(EAP_RESPONSE, identifier, 0, 0, EAP_NAK);
htoun16(data.ptr + 2, data.len);
return eap_payload_create_data(data);
}