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/*
* Copyright (C) 2010 Andreas Steffen
* Copyright (C) 2010 HSR 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 "eap_ttls_avp.h"
#include <debug.h>
#define AVP_EAP_MESSAGE 79
#define AVP_HEADER_LEN 8
typedef struct private_eap_ttls_avp_t private_eap_ttls_avp_t;
/**
* Private data of an eap_ttls_avp_t object.
*/
struct private_eap_ttls_avp_t {
/**
* Public eap_ttls_avp_t interface.
*/
eap_ttls_avp_t public;
/**
* AVP input buffer
*/
chunk_t input;
/**
* Position in input buffer
*/
size_t inpos;
/**
* process header (TRUE) or body (FALSE)
*/
bool process_header;
/**
* Size of AVP data
*/
size_t data_len;
};
METHOD(eap_ttls_avp_t, build, void,
private_eap_ttls_avp_t *this, bio_writer_t *writer, chunk_t data)
{
char zero_padding[] = { 0x00, 0x00, 0x00 };
chunk_t avp_padding;
u_int8_t avp_flags;
u_int32_t avp_len;
avp_flags = 0x40;
avp_len = 8 + data.len;
avp_padding = chunk_create(zero_padding, (4 - data.len) % 4);
writer->write_uint32(writer, AVP_EAP_MESSAGE);
writer->write_uint8(writer, avp_flags);
writer->write_uint24(writer, avp_len);
writer->write_data(writer, data);
writer->write_data(writer, avp_padding);
}
METHOD(eap_ttls_avp_t, process, status_t,
private_eap_ttls_avp_t* this, bio_reader_t *reader, chunk_t *data)
{
size_t len;
chunk_t buf;
if (this->process_header)
{
bio_reader_t *header;
u_int32_t avp_code;
u_int8_t avp_flags;
u_int32_t avp_len;
bool success;
len = min(reader->remaining(reader), AVP_HEADER_LEN - this->inpos);
if (!reader->read_data(reader, len, &buf))
{
return FAILED;
}
if (this->input.len == 0)
{
/* start of a new AVP header */
this->input = chunk_alloc(AVP_HEADER_LEN);
memcpy(this->input.ptr, buf.ptr, len);
this->inpos = len;
}
else
{
memcpy(this->input.ptr + this->inpos, buf.ptr, len);
this->inpos += len;
}
if (this->inpos < AVP_HEADER_LEN)
{
return NEED_MORE;
}
/* parse AVP header */
header = bio_reader_create(this->input);
success = header->read_uint32(header, &avp_code) &&
header->read_uint8(header, &avp_flags) &&
header->read_uint24(header, &avp_len);
header->destroy(header);
chunk_free(&this->input);
this->inpos = 0;
if (!success)
{
DBG1(DBG_IKE, "received invalid AVP header");
return FAILED;
}
if (avp_code != AVP_EAP_MESSAGE)
{
DBG1(DBG_IKE, "expected AVP_EAP_MESSAGE but received %u", avp_code);
return FAILED;
}
this->process_header = FALSE;
this->data_len = avp_len - 8;
this->input = chunk_alloc(this->data_len + (4 - avp_len) % 4);
}
/* process AVP data */
len = min(reader->remaining(reader), this->input.len - this->inpos);
if (!reader->read_data(reader, len, &buf))
{
return FAILED;
}
memcpy(this->input.ptr + this->inpos, buf.ptr, len);
this->inpos += len;
if (this->inpos < this->input.len)
{
return NEED_MORE;
}
*data = this->input;
data->len = this->data_len;
/* preparing for next AVP */
this->input = chunk_empty;
this->inpos = 0;
this->process_header = TRUE;
return SUCCESS;
}
METHOD(eap_ttls_avp_t, destroy, void,
private_eap_ttls_avp_t *this)
{
chunk_free(&this->input);
free(this);
}
/**
* See header
*/
eap_ttls_avp_t *eap_ttls_avp_create(void)
{
private_eap_ttls_avp_t *this;
INIT(this,
.public= {
.process = _process,
.build = _build,
.destroy = _destroy,
},
.input = chunk_empty,
.inpos = 0,
.process_header = TRUE,
.data_len = 0,
);
return &this->public;
}
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