// https://tools.ietf.org/html/rfc3748#section-4.1
// https://tools.ietf.org/html/rfc5281 TTLS v0
// https://tools.ietf.org/html/draft-funk-eap-ttls-v1-00 TTLS v1 (not implemented)
import { IResponseHandlers, ResponseHandler } from './types/Handler';
import { EAPTTLS } from './eap/eap-ttls';
import { MAX_RADIUS_ATTRIBUTE_SIZE } from './helpers';
export class EAPHandler {
eapTTLS: EAPTTLS;
constructor() {
this.eapTTLS = new EAPTTLS(this.sendEAPResponse);
}
/**
*
* @param data
* @param type 1 = identity, 21 = EAP-TTLS, 2 = notification, 4 = md5-challenge, 3 = NAK
*/
private async sendEAPResponse(
response: ResponseHandler,
identifier: number,
data?: Buffer,
msgType = 21,
msgFlags = 0x00
) {
let i = 0;
const maxSize = (MAX_RADIUS_ATTRIBUTE_SIZE - 5) * 4;
let sentDataSize = 0;
let currentIdentifier = identifier;
let currentResponse = response;
do {
// SLICE
// const fragmentMaxPart =
// data && (i + 1) * maxFragmentSize > data.length ? (i + 1) * maxFragmentSize : undefined;
const dataPart = data && data.length > 0 && data.slice(sentDataSize, sentDataSize + maxSize);
/* it's the first one and we have more, therefore include length */
const includeLength = data && i === 0 && sentDataSize < data.length;
sentDataSize += maxSize;
i += 1;
/*
0 1 2 3 4 5 6 7 8
+-+-+-+-+-+-+-+-+
|L M R R R R R R|
+-+-+-+-+-+-+-+-+
L = Length included
M = More fragments
R = Reserved
The L bit (length included) is set to indicate the presence of the
four-octet TLS Message Length field, and MUST be set for the first
fragment of a fragmented TLS message or set of messages. The M
bit (more fragments) is set on all but the last fragment.
Implementations of this specification MUST set the reserved bits
to zero, and MUST ignore them on reception.
*/
const flags =
msgFlags +
(includeLength ? 0b10000000 : 0) + // set L bit
(data && sentDataSize < data.length /* we have more */ ? 0b01000000 : 0); // set M bit
currentIdentifier++;
let buffer = Buffer.from([
1, // request
currentIdentifier,
0, // length (1/2)
0, // length (2/2)
msgType, // 1 = identity, 21 = EAP-TTLS, 2 = notificaiton, 4 = md5-challenge, 3 = NAK
flags // flags: 000000 (L include lenghts, M .. more to come)
]);
// append length
if (includeLength && data) {
const length = Buffer.alloc(4);
length.writeInt32BE(data.byteLength, 0);
buffer = Buffer.concat([buffer, length]);
}
const resBuffer = dataPart ? Buffer.concat([buffer, dataPart]) : buffer;
resBuffer.writeUInt16BE(resBuffer.byteLength, 2);
console.log('<<<<<<<<<<<< EAP RESPONSE TO CLIENT', {
code: 1,
currentIdentifier,
includeLength,
length: (data && data.byteLength) || 0,
msgType: msgType.toString(10),
flags: `00000000${flags.toString(2)}`.substr(-8),
data
});
// uffer.from([1,identifier, 0, 0, 21, 0]);
// buffer.writeUInt16BE(sslResponse.length, 2); // length
// buffer.writeInt8(21, 4); // eap-ttls
// buffer.writeInt8(0, 5); // flags
console.log('sending message with identifier', currentIdentifier);
({ identifier: currentIdentifier, response: currentResponse } = await currentResponse(
resBuffer
));
console.log('next message got identifier', currentIdentifier);
} while (data && sentDataSize < data.length);
console.log('DONE', sentDataSize, data && data.length);
}
handleEAPMessage(msg: Buffer, state: string, handlers: IResponseHandlers) {
// const b = Buffer.from([2,0x242,0x0,0x18,0x1,0x115,0x105,0x109,0x111,0x110,0x46,0x116,0x114,0x101,0x116,0x116,0x101,0x114]);
// const msg = Buffer.from([2, 162, 0, 18, 1, 115, 105, 109, 111, 110, 46, 116, 114, 101, 116, 116, 101, 114])
/*
1 Request
2 Response
3 Success
4 Failure
*/
const code = msg.slice(0, 1).readUInt8(0);
const identifier = msg.slice(1, 2).readUInt8(0); // .toString('hex');
// const length = msg.slice(2, 4).readInt16BE(0); // .toString('binary');
const type = msg.slice(4, 5).readUInt8(0); // .slice(3,0x5).toString('hex');
/*
console.log("CODE", code);
console.log('ID', identifier);
console.log('length', length);
*/
switch (code) {
case 1: // for request
case 2: // for response
switch (type) {
case 1: // identifiy
/**
* The EAP-TTLS packet format is shown below. The fields are
transmitted left to right.
0 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Identifier | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Flags | Message Length
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Message Length | Data...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
console.log('>>>>>>>>>>>> REQUEST FROM CLIENT: IDENTIFY', {});
this.sendEAPResponse(handlers.response, identifier, undefined, 21, 0x20);
/*
handlers.response(
Buffer.from([
1, // request
identifier + 1,
0, // length (1/2)
6, // length (2/2)
21, // EAP-TTLS
0x20 // flags: 001000 start flag
])
); */
break;
case 21: // EAP TTLS
this.eapTTLS.handleMessage(msg, state, handlers, identifier);
break;
case 3: // nak
// this.sendEAPResponse(handlers.response, identifier, undefined, 3);
break;
case 2: // notification
console.log('>>>>>>>>>>>> REQUEST FROM CLIENT: notification', {});
console.info('notification');
break;
case 4: // md5-challenge
console.log('>>>>>>>>>>>> REQUEST FROM CLIENT: md5-challenge', {});
console.info('md5-challenge');
break;
case 254: // expanded type
console.error('not implemented type', type);
break;
default:
// we do not support this auth type, ask for TTLS
console.error('unsupported type', type, 'requesting TTLS (21)');
this.sendEAPResponse(handlers.response, identifier, Buffer.from([21]), 3);
break;
}
break;
case 3:
console.log('Client Auth Success');
break;
case 4:
console.log('Client Auth FAILURE');
break;
default:
break;
// silently ignor;
}
}
}