468 lines
10 KiB
C
468 lines
10 KiB
C
/*
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* Copyright (C) 2012 Tobias Brunner
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* Copyright (C) 2005-2010 Martin Willi
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* Copyright (C) 2005 Jan Hutter
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* HSR Hochschule fuer Technik Rapperswil
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*/
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#include <stddef.h>
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#include "eap_payload.h"
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#include <daemon.h>
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#include <eap/eap.h>
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#include <bio/bio_writer.h>
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typedef struct private_eap_payload_t private_eap_payload_t;
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/**
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* Private data of an eap_payload_t object.
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*
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*/
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struct private_eap_payload_t {
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/**
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* Public eap_payload_t interface.
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*/
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eap_payload_t public;
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/**
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* Next payload type.
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*/
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uint8_t next_payload;
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/**
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* Critical flag.
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*/
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bool critical;
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/**
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* Reserved bits
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*/
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bool reserved[7];
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/**
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* Length of this payload.
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*/
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uint16_t payload_length;
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/**
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* EAP message data, if available
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*/
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chunk_t data;
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};
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/**
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* Encoding rules to parse or generate a EAP payload.
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*
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* The defined offsets are the positions in a object of type
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* private_eap_payload_t.
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*
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*/
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static encoding_rule_t encodings[] = {
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/* 1 Byte next payload type, stored in the field next_payload */
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{ U_INT_8, offsetof(private_eap_payload_t, next_payload) },
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/* the critical bit */
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{ FLAG, offsetof(private_eap_payload_t, critical) },
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/* 7 Bit reserved bits, nowhere stored */
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[0]) },
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[1]) },
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[2]) },
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[3]) },
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[4]) },
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[5]) },
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{ RESERVED_BIT, offsetof(private_eap_payload_t, reserved[6]) },
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/* Length of the whole payload*/
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{ PAYLOAD_LENGTH, offsetof(private_eap_payload_t, payload_length) },
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/* chunk to data, starting at "code" */
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{ CHUNK_DATA, offsetof(private_eap_payload_t, data) },
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};
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/*
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1 2 3
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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
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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! Next Payload !C! RESERVED ! Payload Length !
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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! Code ! Identifier ! Length !
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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! Type ! Type_Data...
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
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*/
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METHOD(payload_t, verify, status_t,
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private_eap_payload_t *this)
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{
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uint16_t length;
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uint8_t code;
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if (this->data.len < 4)
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{
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DBG1(DBG_ENC, "EAP payloads EAP message too short (%d)", this->data.len);
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return FAILED;
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}
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length = untoh16(this->data.ptr + 2);
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if (this->data.len != length)
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{
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DBG1(DBG_ENC, "EAP payload length (%d) does not match contained "
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"message length (%d)", this->data.len, length);
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return FAILED;
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}
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code = this->data.ptr[0];
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switch (code)
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{
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case EAP_REQUEST:
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case EAP_RESPONSE:
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{
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if (this->data.len < 4)
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{
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DBG1(DBG_ENC, "EAP Request/Response does not have any data");
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return FAILED;
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}
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break;
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}
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case EAP_SUCCESS:
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case EAP_FAILURE:
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{
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if (this->data.len != 4)
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{
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DBG1(DBG_ENC, "EAP Success/Failure has data");
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return FAILED;
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}
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break;
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}
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default:
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return FAILED;
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}
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return SUCCESS;
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}
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METHOD(payload_t, get_encoding_rules, int,
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private_eap_payload_t *this, encoding_rule_t **rules)
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{
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*rules = encodings;
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return countof(encodings);
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}
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METHOD(payload_t, get_header_length, int,
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private_eap_payload_t *this)
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{
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return 4;
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}
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METHOD(payload_t, get_payload_type, payload_type_t,
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private_eap_payload_t *this)
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{
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return PLV2_EAP;
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}
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METHOD(payload_t, get_next_type, payload_type_t,
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private_eap_payload_t *this)
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{
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return (this->next_payload);
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}
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METHOD(payload_t, set_next_type, void,
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private_eap_payload_t *this, payload_type_t type)
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{
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this->next_payload = type;
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}
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METHOD(payload_t, get_length, size_t,
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private_eap_payload_t *this)
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{
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return this->payload_length;
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}
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METHOD(eap_payload_t, get_data, chunk_t,
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private_eap_payload_t *this)
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{
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return this->data;
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}
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METHOD(eap_payload_t, set_data, void,
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private_eap_payload_t *this, chunk_t data)
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{
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free(this->data.ptr);
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this->data = chunk_clone(data);
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this->payload_length = this->data.len + 4;
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}
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METHOD(eap_payload_t, get_code, eap_code_t,
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private_eap_payload_t *this)
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{
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if (this->data.len > 0)
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{
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return this->data.ptr[0];
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}
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/* should not happen, as it is verified */
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return 0;
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}
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METHOD(eap_payload_t, get_identifier, uint8_t,
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private_eap_payload_t *this)
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{
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if (this->data.len > 1)
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{
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return this->data.ptr[1];
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}
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/* should not happen, as it is verified */
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return 0;
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}
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/**
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* Get the current type at the given offset into this->data.
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* @return the new offset or 0 if failed
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*/
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static size_t extract_type(private_eap_payload_t *this, size_t offset,
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eap_type_t *type, uint32_t *vendor)
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{
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if (this->data.len > offset)
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{
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*vendor = 0;
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*type = this->data.ptr[offset];
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if (*type != EAP_EXPANDED)
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{
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return offset + 1;
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}
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if (this->data.len >= offset + 8)
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{
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*vendor = untoh32(this->data.ptr + offset) & 0x00FFFFFF;
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*type = untoh32(this->data.ptr + offset + 4);
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return offset + 8;
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}
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}
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return 0;
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}
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METHOD(eap_payload_t, get_type, eap_type_t,
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private_eap_payload_t *this, uint32_t *vendor)
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{
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eap_type_t type;
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*vendor = 0;
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if (extract_type(this, 4, &type, vendor))
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{
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return type;
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}
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return 0;
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}
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/**
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* Type enumerator
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*/
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typedef struct {
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/** public interface */
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enumerator_t public;
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/** payload */
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private_eap_payload_t *payload;
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/** current offset in the data */
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size_t offset;
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} type_enumerator_t;
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METHOD(enumerator_t, enumerate_types, bool,
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type_enumerator_t *this, va_list args)
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{
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eap_type_t *type;
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uint32_t *vendor;
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VA_ARGS_VGET(args, type, vendor);
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this->offset = extract_type(this->payload, this->offset, type, vendor);
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return this->offset;
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}
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METHOD(eap_payload_t, get_types, enumerator_t*,
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private_eap_payload_t *this)
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{
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type_enumerator_t *enumerator;
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eap_type_t type;
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uint32_t vendor;
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size_t offset;
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offset = extract_type(this, 4, &type, &vendor);
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if (offset && type == EAP_NAK)
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{
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INIT(enumerator,
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.public = {
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.enumerate = enumerator_enumerate_default,
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.venumerate = _enumerate_types,
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.destroy = (void*)free,
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},
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.payload = this,
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.offset = offset,
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);
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return &enumerator->public;
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}
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return enumerator_create_empty();
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}
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METHOD(eap_payload_t, is_expanded, bool,
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private_eap_payload_t *this)
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{
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return this->data.len > 4 ? this->data.ptr[4] == EAP_EXPANDED : FALSE;
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}
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METHOD2(payload_t, eap_payload_t, destroy, void,
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private_eap_payload_t *this)
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{
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chunk_free(&this->data);
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free(this);
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}
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/*
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* Described in header
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*/
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eap_payload_t *eap_payload_create()
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{
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private_eap_payload_t *this;
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INIT(this,
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.public = {
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.payload_interface = {
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.verify = _verify,
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.get_encoding_rules = _get_encoding_rules,
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.get_header_length = _get_header_length,
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.get_length = _get_length,
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.get_next_type = _get_next_type,
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.set_next_type = _set_next_type,
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.get_type = _get_payload_type,
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.destroy = _destroy,
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},
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.get_data = _get_data,
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.set_data = _set_data,
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.get_code = _get_code,
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.get_identifier = _get_identifier,
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.get_type = _get_type,
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.get_types = _get_types,
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.is_expanded = _is_expanded,
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.destroy = _destroy,
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},
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.next_payload = PL_NONE,
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.payload_length = get_header_length(this),
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);
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return &this->public;
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}
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/*
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* Described in header
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*/
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eap_payload_t *eap_payload_create_data(chunk_t data)
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{
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eap_payload_t *this = eap_payload_create();
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this->set_data(this, data);
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return this;
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}
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/*
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* Described in header
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*/
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eap_payload_t *eap_payload_create_data_own(chunk_t data)
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{
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eap_payload_t *this = eap_payload_create();
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this->set_data(this, data);
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free(data.ptr);
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return this;
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}
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/*
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* Described in header
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*/
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eap_payload_t *eap_payload_create_code(eap_code_t code, uint8_t identifier)
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{
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chunk_t data;
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data = chunk_from_chars(code, identifier, 0, 0);
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htoun16(data.ptr + 2, data.len);
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return eap_payload_create_data(data);
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}
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/**
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* Write the given type either expanded or not
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*/
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static void write_type(bio_writer_t *writer, eap_type_t type, uint32_t vendor,
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bool expanded)
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{
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if (expanded)
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{
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writer->write_uint8(writer, EAP_EXPANDED);
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writer->write_uint24(writer, vendor);
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writer->write_uint32(writer, type);
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}
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else
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{
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writer->write_uint8(writer, type);
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}
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}
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/*
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* Described in header
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*/
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eap_payload_t *eap_payload_create_nak(uint8_t identifier, eap_type_t type,
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uint32_t vendor, bool expanded)
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{
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enumerator_t *enumerator;
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eap_type_t reg_type;
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uint32_t reg_vendor;
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bio_writer_t *writer;
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chunk_t data;
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bool added_any = FALSE, found_vendor = FALSE;
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eap_payload_t *payload;
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writer = bio_writer_create(12);
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writer->write_uint8(writer, EAP_RESPONSE);
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writer->write_uint8(writer, identifier);
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/* write zero length, we update it once we know the length */
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writer->write_uint16(writer, 0);
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write_type(writer, EAP_NAK, 0, expanded);
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enumerator = charon->eap->create_enumerator(charon->eap, EAP_PEER);
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while (enumerator->enumerate(enumerator, ®_type, ®_vendor))
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{
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if ((type && type != reg_type) ||
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(type && vendor && vendor != reg_vendor))
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{ /* the preferred type is only sent if we actually find it */
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continue;
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}
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if (!reg_vendor || expanded)
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{
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write_type(writer, reg_type, reg_vendor, expanded);
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added_any = TRUE;
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}
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else if (reg_vendor)
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{ /* found vendor specific method, but this is not an expanded Nak */
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found_vendor = TRUE;
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}
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}
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enumerator->destroy(enumerator);
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if (found_vendor)
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{ /* request an expanded authentication type */
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write_type(writer, EAP_EXPANDED, 0, expanded);
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added_any = TRUE;
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}
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if (!added_any)
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{ /* no methods added */
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write_type(writer, 0, 0, expanded);
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}
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/* set length */
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data = writer->get_buf(writer);
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htoun16(data.ptr + offsetof(eap_packet_t, length), data.len);
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payload = eap_payload_create_data(data);
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writer->destroy(writer);
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return payload;
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}
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