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strongswan-ext/src/charon/encoding/payloads/eap_payload.c
T

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C

/*
* 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 "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;
/**
* 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.
*
*/
encoding_rule_t eap_payload_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, 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_eap_payload_t, payload_length) },
/* chunt to data, starting at "code" */
{ EAP_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...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
*/
/**
* Implementation of payload_t.verify.
*/
static status_t verify(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;
}
code = *this->data.ptr;
length = htons(*(u_int16_t*)(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;
}
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;
}
/**
* Implementation of eap_payload_t.get_encoding_rules.
*/
static void get_encoding_rules(private_eap_payload_t *this, encoding_rule_t **rules, size_t *rule_count)
{
*rules = eap_payload_encodings;
*rule_count = sizeof(eap_payload_encodings) / sizeof(encoding_rule_t);
}
/**
* Implementation of payload_t.get_type.
*/
static payload_type_t get_payload_type(private_eap_payload_t *this)
{
return EXTENSIBLE_AUTHENTICATION;
}
/**
* Implementation of payload_t.get_next_type.
*/
static payload_type_t get_next_type(private_eap_payload_t *this)
{
return (this->next_payload);
}
/**
* Implementation of payload_t.set_next_type.
*/
static void set_next_type(private_eap_payload_t *this,payload_type_t type)
{
this->next_payload = type;
}
/**
* Implementation of payload_t.get_length.
*/
static size_t get_length(private_eap_payload_t *this)
{
return this->payload_length;
}
/**
* Implementation of eap_payload_t.get_data.
*/
static chunk_t get_data(private_eap_payload_t *this)
{
return this->data;
}
/**
* Implementation of eap_payload_t.set_data.
*/
static void set_data(private_eap_payload_t *this, chunk_t data)
{
chunk_free(&this->data);
this->data = chunk_clone(data);
this->payload_length = this->data.len + 4;
}
/**
* Implementation of eap_payload_t.get_code.
*/
static eap_code_t get_code(private_eap_payload_t *this)
{
if (this->data.len > 0)
{
return *this->data.ptr;
}
/* should not happen, as it is verified */
return 0;
}
/**
* Implementation of eap_payload_t.get_identifier.
*/
static u_int8_t get_identifier(private_eap_payload_t *this)
{
if (this->data.len > 1)
{
return *(this->data.ptr + 1);
}
/* should not happen, as it is verified */
return 0;
}
/**
* Implementation of eap_payload_t.get_type.
*/
static eap_type_t get_type(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 = ntohl(*(u_int32_t*)(this->data.ptr + 4)) & 0x00FFFFFF;
return ntohl(*(u_int32_t*)(this->data.ptr + 8));
}
}
return 0;
}
/**
* Implementation of payload_t.destroy and eap_payload_t.destroy.
*/
static void destroy(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 = malloc_thing(private_eap_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_payload_type;
this->public.payload_interface.destroy = (void (*) (payload_t *))destroy;
/* public functions */
this->public.destroy = (void (*) (eap_payload_t *)) destroy;
this->public.get_data = (chunk_t (*) (eap_payload_t*))get_data;
this->public.set_data = (void (*) (eap_payload_t *,chunk_t))set_data;
this->public.get_code = (eap_code_t (*) (eap_payload_t*))get_code;
this->public.get_identifier = (u_int8_t (*) (eap_payload_t*))get_identifier;
this->public.get_type = (eap_type_t (*) (eap_payload_t*,u_int32_t*))get_type;
/* private variables */
this->critical = FALSE;
this->next_payload = NO_PAYLOAD;
this->payload_length = EAP_PAYLOAD_HEADER_LENGTH;
this->data = chunk_empty;
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_code(eap_code_t code, u_int8_t identifier)
{
eap_payload_t *this = eap_payload_create();
chunk_t data = chunk_alloca(4);
*(data.ptr + 0) = code;
*(data.ptr + 1) = identifier;
*(u_int16_t*)(data.ptr + 2) = htons(data.len);
this->set_data(this, data);
return this;
}
/*
* Described in header
*/
eap_payload_t *eap_payload_create_nak(u_int8_t identifier)
{
eap_payload_t *this = eap_payload_create();
chunk_t data = chunk_alloca(5);
*(data.ptr + 0) = EAP_RESPONSE;
*(data.ptr + 1) = identifier;
*(u_int16_t*)(data.ptr + 2) = htons(data.len);
*(data.ptr + 4) = EAP_NAK;
this->set_data(this, data);
return this;
}