MeshCentral/interceptor.js
2021-03-13 21:26:59 -08:00

460 lines
23 KiB
JavaScript

/**
* @description MeshCentral Intel(R) AMT Interceptor
* @author Ylian Saint-Hilaire
* @copyright Intel Corporation 2018-2021
* @license Apache-2.0
* @version v0.0.3
*/
/*xjslint node: true */
/*xjslint plusplus: true */
/*xjslint maxlen: 256 */
/*jshint node: true */
/*jshint strict: false */
/*jshint esversion: 6 */
'use strict';
const crypto = require('crypto');
const common = require('./common.js');
var HttpInterceptorAuthentications = {};
//var RedirInterceptorAuthentications = {};
// Construct a HTTP interceptor object
module.exports.CreateHttpInterceptor = function (args) {
var obj = {};
// Create a random hex string of a given length
obj.randomValueHex = function (len) { return crypto.randomBytes(Math.ceil(len / 2)).toString('hex').slice(0, len); };
obj.args = args;
obj.amt = { acc: '', mode: 0, count: 0, error: false }; // mode: 0:Header, 1:LengthBody, 2:ChunkedBody, 3:UntilClose
obj.ws = { acc: '', mode: 0, count: 0, error: false, authCNonce: obj.randomValueHex(10), authCNonceCount: 1 };
obj.blockAmtStorage = false;
// Private method
obj.Debug = function (msg) { console.log(msg); };
// Process data coming from Intel AMT
obj.processAmtData = function (data) {
obj.amt.acc += data.toString('binary'); // Add data to accumulator
data = '';
var datalen = 0;
do { datalen = data.length; data += obj.processAmtDataEx(); } while (datalen != data.length); // Process as much data as possible
return Buffer.from(data, 'binary');
};
// Process data coming from AMT in the accumulator
obj.processAmtDataEx = function () {
var i, r, headerend;
if (obj.amt.mode == 0) { // Header Mode
// Decode the HTTP header
headerend = obj.amt.acc.indexOf('\r\n\r\n');
if (headerend < 0) return '';
var headerlines = obj.amt.acc.substring(0, headerend).split('\r\n');
obj.amt.acc = obj.amt.acc.substring(headerend + 4);
obj.amt.directive = headerlines[0].split(' ');
var headers = headerlines.slice(1);
obj.amt.headers = {};
obj.amt.mode = 3; // UntilClose
for (i in headers) {
var j = headers[i].indexOf(':');
if (j > 0) {
var v1 = headers[i].substring(0, j).trim().toLowerCase();
var v2 = headers[i].substring(j + 1).trim();
obj.amt.headers[v1] = v2;
if (v1.toLowerCase() == 'www-authenticate') {
HttpInterceptorAuthentications[obj.args.host + ':' + obj.args.port] = v2;
} else if (v1.toLowerCase() == 'content-length') {
obj.amt.count = parseInt(v2);
if (obj.amt.count > 0) {
obj.amt.mode = 1; // LengthBody
} else {
obj.amt.mode = 0; // Header
}
} else if (v1.toLowerCase() == 'transfer-encoding' && v2.toLowerCase() == 'chunked') {
obj.amt.mode = 2; // ChunkedBody
}
}
}
// Reform the HTTP header
r = obj.amt.directive.join(' ') + '\r\n';
for (i in obj.amt.headers) { r += (i + ': ' + obj.amt.headers[i] + '\r\n'); }
r += '\r\n';
return r;
} else if (obj.amt.mode == 1) { // Length Body Mode
// Send the body of content-length size
var rl = obj.amt.count;
if (rl < obj.amt.acc.length) rl = obj.amt.acc.length;
r = obj.amt.acc.substring(0, rl);
obj.amt.acc = obj.amt.acc.substring(rl);
obj.amt.count -= rl;
if (obj.amt.count == 0) { obj.amt.mode = 0; }
return r;
} else if (obj.amt.mode == 2) { // Chunked Body Mode
// Send data one chunk at a time
headerend = obj.amt.acc.indexOf('\r\n');
if (headerend < 0) return '';
var chunksize = parseInt(obj.amt.acc.substring(0, headerend), 16);
if ((chunksize == 0) && (obj.amt.acc.length >= headerend + 4)) {
// Send the ending chunk (NOTE: We do not support trailing headers)
r = obj.amt.acc.substring(0, headerend + 4);
obj.amt.acc = obj.amt.acc.substring(headerend + 4);
obj.amt.mode = 0;
return r;
} else if ((chunksize > 0) && (obj.amt.acc.length >= (headerend + 4 + chunksize))) {
// Send a chunk
r = obj.amt.acc.substring(0, headerend + chunksize + 4);
obj.amt.acc = obj.amt.acc.substring(headerend + chunksize + 4);
return r;
}
} else if (obj.amt.mode == 3) { // Until Close Mode
r = obj.amt.acc;
obj.amt.acc = '';
return r;
}
return '';
};
// Process data coming from the Browser
obj.processBrowserData = function (data) {
obj.ws.acc += data.toString('binary'); // Add data to accumulator
data = '';
var datalen = 0;
do { datalen = data.length; data += obj.processBrowserDataEx(); } while (datalen != data.length); // Process as much data as possible
return Buffer.from(data, 'binary');
};
// Process data coming from the Browser in the accumulator
obj.processBrowserDataEx = function () {
var i, r, headerend;
if (obj.ws.mode == 0) { // Header Mode
// Decode the HTTP header
headerend = obj.ws.acc.indexOf('\r\n\r\n');
if (headerend < 0) return '';
var headerlines = obj.ws.acc.substring(0, headerend).split('\r\n');
obj.ws.acc = obj.ws.acc.substring(headerend + 4);
obj.ws.directive = headerlines[0].split(' ');
// If required, block access to amt-storage. This is needed when web storage is not supported on CIRA.
if ((obj.blockAmtStorage == true) && (obj.ws.directive.length > 1) && (obj.ws.directive[1].indexOf('/amt-storage') == 0)) { obj.ws.directive[1] = obj.ws.directive[1].replace('/amt-storage', '/amt-dummy-storage'); }
var headers = headerlines.slice(1);
obj.ws.headers = {};
obj.ws.mode = 3; // UntilClose
for (i in headers) {
var j = headers[i].indexOf(':');
if (j > 0) {
var v1 = headers[i].substring(0, j).trim().toLowerCase();
var v2 = headers[i].substring(j + 1).trim();
obj.ws.headers[v1] = v2;
if (v1.toLowerCase() == 'www-authenticate') {
HttpInterceptorAuthentications[obj.args.host + ':' + obj.args.port] = v2;
} else if (v1.toLowerCase() == 'content-length') {
obj.ws.count = parseInt(v2);
if (obj.ws.count > 0) {
obj.ws.mode = 1; // LengthBody
} else {
obj.ws.mode = 0; // Header
}
} else if (v1.toLowerCase() == 'transfer-encoding' && v2.toLowerCase() == 'chunked') {
obj.ws.mode = 2; // ChunkedBody
}
}
}
// Insert authentication
if (obj.args.user && obj.args.pass && HttpInterceptorAuthentications[obj.args.host + ':' + obj.args.port]) {
// We have authentication data, lets use it.
var AuthArgs = obj.GetAuthArgs(HttpInterceptorAuthentications[obj.args.host + ':' + obj.args.port]);
// If different QOP options are proposed, always use 'auth' for now.
AuthArgs.qop = 'auth';
// In the future, we should support auth-int, but that will required the body of the request to be accumulated and hashed.
/*
if (AuthArgs.qop != null) { // If Intel AMT supports auth-int, use it.
var qopList = AuthArgs.qop.split(',');
for (var i in qopList) { qopList[i] = qopList[i].trim(); }
if (qopList.indexOf('auth-int') >= 0) { AuthArgs.qop = 'auth-int'; } else { AuthArgs.qop = 'auth'; }
}
*/
var hash = obj.ComputeDigesthash(obj.args.user, obj.args.pass, AuthArgs.realm, obj.ws.directive[0], obj.ws.directive[1], AuthArgs.qop, AuthArgs.nonce, obj.ws.authCNonceCount, obj.ws.authCNonce);
var authstr = 'Digest username="' + obj.args.user + '",realm="' + AuthArgs.realm + '",nonce="' + AuthArgs.nonce + '",uri="' + obj.ws.directive[1] + '",qop=' + AuthArgs.qop + ',nc=' + obj.ws.authCNonceCount + ',cnonce="' + obj.ws.authCNonce + '",response="' + hash + '"';
if (AuthArgs.opaque) { authstr += (',opaque="' + AuthArgs.opaque + '"'); }
obj.ws.headers.authorization = authstr;
obj.ws.authCNonceCount++;
} else {
// We don't have authentication, clear it out of the header if needed.
if (obj.ws.headers.authorization) { delete obj.ws.headers.authorization; }
}
// Reform the HTTP header
r = obj.ws.directive.join(' ') + '\r\n';
for (i in obj.ws.headers) { r += (i + ': ' + obj.ws.headers[i] + '\r\n'); }
r += '\r\n';
return r;
} else if (obj.ws.mode == 1) { // Length Body Mode
// Send the body of content-length size
var rl = obj.ws.count;
if (rl < obj.ws.acc.length) rl = obj.ws.acc.length;
r = obj.ws.acc.substring(0, rl);
obj.ws.acc = obj.ws.acc.substring(rl);
obj.ws.count -= rl;
if (obj.ws.count == 0) { obj.ws.mode = 0; }
return r;
} else if (obj.amt.mode == 2) { // Chunked Body Mode
// Send data one chunk at a time
headerend = obj.amt.acc.indexOf('\r\n');
if (headerend < 0) return '';
var chunksize = parseInt(obj.amt.acc.substring(0, headerend), 16);
if (isNaN(chunksize)) { // TODO: Check this path
// Chunk is not in this batch, move one
r = obj.amt.acc.substring(0, headerend + 2);
obj.amt.acc = obj.amt.acc.substring(headerend + 2);
// Peek if we next is the end of chunked transfer
headerend = obj.amt.acc.indexOf('\r\n');
if (headerend > 0) {
chunksize = parseInt(obj.amt.acc.substring(0, headerend), 16);
if (chunksize == 0) { obj.amt.mode = 0; }
}
return r;
} else if (chunksize == 0 && obj.amt.acc.length >= headerend + 4) {
// Send the ending chunk (NOTE: We do not support trailing headers)
r = obj.amt.acc.substring(0, headerend + 4);
obj.amt.acc = obj.amt.acc.substring(headerend + 4);
obj.amt.mode = 0;
return r;
} else if (chunksize > 0 && obj.amt.acc.length >= headerend + 4) {
// Send a chunk
r = obj.amt.acc.substring(0, headerend + chunksize + 4);
obj.amt.acc = obj.amt.acc.substring(headerend + chunksize + 4);
return r;
}
} else if (obj.ws.mode == 3) { // Until Close Mode
r = obj.ws.acc;
obj.ws.acc = '';
return r;
}
return '';
};
// Parse authentication values from the HTTP header
obj.GetAuthArgs = function (authheader) {
var authargs = {};
var authargsstr = authheader.substring(7).split(',');
for (var j in authargsstr) {
var argstr = authargsstr[j];
var i = argstr.indexOf('=');
var k = argstr.substring(0, i).trim().toLowerCase();
var v = argstr.substring(i + 1).trim();
if (v.substring(0, 1) == '\"') { v = v.substring(1, v.length - 1); }
if (i > 0) authargs[k] = v;
}
return authargs;
};
// Compute the MD5 digest hash for a set of values
obj.ComputeDigesthash = function (username, password, realm, method, path, qop, nonce, nc, cnonce) {
var ha1 = crypto.createHash('md5').update(username + ':' + realm + ':' + password).digest('hex');
var ha2 = crypto.createHash('md5').update(method + ':' + path).digest('hex');
return crypto.createHash('md5').update(ha1 + ':' + nonce + ':' + nc + ':' + cnonce + ':' + qop + ':' + ha2).digest('hex');
};
return obj;
};
// Construct a redirection interceptor object
module.exports.CreateRedirInterceptor = function (args) {
var obj = {};
// Create a random hex string of a given length
obj.randomValueHex = function (len) { return crypto.randomBytes(Math.ceil(len / 2)).toString('hex').slice(0, len); };
obj.args = args;
obj.amt = { acc: '', mode: 0, count: 0, error: false, direct: false };
obj.ws = { acc: '', mode: 0, count: 0, error: false, direct: false, authCNonce: obj.randomValueHex(10), authCNonceCount: 1 };
obj.RedirectCommands = { StartRedirectionSession: 0x10, StartRedirectionSessionReply: 0x11, EndRedirectionSession: 0x12, AuthenticateSession: 0x13, AuthenticateSessionReply: 0x14 };
obj.StartRedirectionSessionReplyStatus = { SUCCESS: 0, TYPE_UNKNOWN: 1, BUSY: 2, UNSUPPORTED: 3, ERROR: 0xFF };
obj.AuthenticationStatus = { SUCCESS: 0, FALIURE: 1, NOTSUPPORTED: 2 };
obj.AuthenticationType = { QUERY: 0, USERPASS: 1, KERBEROS: 2, BADDIGEST: 3, DIGEST: 4 };
// Private method
obj.Debug = function (msg) { console.log(msg); };
// Process data coming from Intel AMT
obj.processAmtData = function (data) {
if ((obj.amt.direct == true) && (obj.amt.acc == '')) { return data; } // Interceptor fast path
obj.amt.acc += data.toString('binary'); // Add data to accumulator
data = '';
var datalen = 0;
do { datalen = data.length; data += obj.processAmtDataEx(); } while (datalen != data.length); // Process as much data as possible
return Buffer.from(data, 'binary');
};
// Process data coming from AMT in the accumulator
obj.processAmtDataEx = function () {
var r;
if (obj.amt.acc.length == 0) return '';
if (obj.amt.direct == true) {
var data = obj.amt.acc;
obj.amt.acc = '';
return data;
} else {
//console.log(obj.amt.acc.charCodeAt(0));
switch (obj.amt.acc.charCodeAt(0)) {
case obj.RedirectCommands.StartRedirectionSessionReply: {
if (obj.amt.acc.length < 4) return '';
if (obj.amt.acc.charCodeAt(1) == obj.StartRedirectionSessionReplyStatus.SUCCESS) {
if (obj.amt.acc.length < 13) return '';
var oemlen = obj.amt.acc.charCodeAt(12);
if (obj.amt.acc.length < 13 + oemlen) return '';
r = obj.amt.acc.substring(0, 13 + oemlen);
obj.amt.acc = obj.amt.acc.substring(13 + oemlen);
return r;
}
break;
}
case obj.RedirectCommands.AuthenticateSessionReply: {
if (obj.amt.acc.length < 9) return '';
var l = common.ReadIntX(obj.amt.acc, 5);
if (obj.amt.acc.length < 9 + l) return '';
var authstatus = obj.amt.acc.charCodeAt(1);
var authType = obj.amt.acc.charCodeAt(4);
if ((authType == obj.AuthenticationType.DIGEST) && (authstatus == obj.AuthenticationStatus.FALIURE)) {
// Grab and keep all authentication parameters
var realmlen = obj.amt.acc.charCodeAt(9);
obj.amt.digestRealm = obj.amt.acc.substring(10, 10 + realmlen);
var noncelen = obj.amt.acc.charCodeAt(10 + realmlen);
obj.amt.digestNonce = obj.amt.acc.substring(11 + realmlen, 11 + realmlen + noncelen);
var qoplen = obj.amt.acc.charCodeAt(11 + realmlen + noncelen);
obj.amt.digestQOP = obj.amt.acc.substring(12 + realmlen + noncelen, 12 + realmlen + noncelen + qoplen);
}
else if (authType != obj.AuthenticationType.QUERY && authstatus == obj.AuthenticationStatus.SUCCESS) {
// Intel AMT relayed that authentication was successful, go to direct relay mode in both directions.
obj.ws.direct = true;
obj.amt.direct = true;
}
r = obj.amt.acc.substring(0, 9 + l);
obj.amt.acc = obj.amt.acc.substring(9 + l);
return r;
}
default: {
obj.amt.error = true;
return '';
}
}
}
return '';
};
// Process data coming from the Browser
obj.processBrowserData = function (data) {
if ((obj.ws.direct == true) && (obj.ws.acc == '')) { return data; } // Interceptor fast path
obj.ws.acc += data.toString('binary'); // Add data to accumulator
data = '';
var datalen = 0;
do { datalen = data.length; data += obj.processBrowserDataEx(); } while (datalen != data.length); // Process as much data as possible
return Buffer.from(data, 'binary');
};
// Process data coming from the Browser in the accumulator
obj.processBrowserDataEx = function () {
var r;
if (obj.ws.acc.length == 0) return '';
if (obj.ws.direct == true) {
var data = obj.ws.acc;
obj.ws.acc = '';
return data;
} else {
switch (obj.ws.acc.charCodeAt(0)) {
case obj.RedirectCommands.StartRedirectionSession: {
if (obj.ws.acc.length < 8) return '';
r = obj.ws.acc.substring(0, 8);
obj.ws.acc = obj.ws.acc.substring(8);
return r;
}
case obj.RedirectCommands.EndRedirectionSession: {
if (obj.ws.acc.length < 4) return '';
r = obj.ws.acc.substring(0, 4);
obj.ws.acc = obj.ws.acc.substring(4);
return r;
}
case obj.RedirectCommands.AuthenticateSession: {
if (obj.ws.acc.length < 9) return '';
var l = common.ReadIntX(obj.ws.acc, 5);
if (obj.ws.acc.length < 9 + l) return '';
var authType = obj.ws.acc.charCodeAt(4);
if (authType == obj.AuthenticationType.DIGEST && obj.args.user && obj.args.pass) {
var authurl = '/RedirectionService';
if (obj.amt.digestRealm) {
// Replace this authentication digest with a server created one
// We have everything we need to authenticate
var nc = obj.ws.authCNonceCount;
obj.ws.authCNonceCount++;
var digest = obj.ComputeDigesthash(obj.args.user, obj.args.pass, obj.amt.digestRealm, 'POST', authurl, obj.amt.digestQOP, obj.amt.digestNonce, nc, obj.ws.authCNonce);
// Replace this authentication digest with a server created one
// We have everything we need to authenticate
r = String.fromCharCode(0x13, 0x00, 0x00, 0x00, 0x04);
r += common.IntToStrX(obj.args.user.length + obj.amt.digestRealm.length + obj.amt.digestNonce.length + authurl.length + obj.ws.authCNonce.length + nc.toString().length + digest.length + obj.amt.digestQOP.length + 8);
r += String.fromCharCode(obj.args.user.length); // Username Length
r += obj.args.user; // Username
r += String.fromCharCode(obj.amt.digestRealm.length); // Realm Length
r += obj.amt.digestRealm; // Realm
r += String.fromCharCode(obj.amt.digestNonce.length); // Nonce Length
r += obj.amt.digestNonce; // Nonce
r += String.fromCharCode(authurl.length); // Authentication URL "/RedirectionService" Length
r += authurl; // Authentication URL
r += String.fromCharCode(obj.ws.authCNonce.length); // CNonce Length
r += obj.ws.authCNonce; // CNonce
r += String.fromCharCode(nc.toString().length); // NonceCount Length
r += nc.toString(); // NonceCount
r += String.fromCharCode(digest.length); // Response Length
r += digest; // Response
r += String.fromCharCode(obj.amt.digestQOP.length); // QOP Length
r += obj.amt.digestQOP; // QOP
obj.ws.acc = obj.ws.acc.substring(9 + l); // Don't relay the original message
return r;
} else {
// Replace this authentication digest with a server created one
// Since we don't have authentication parameters, fill them in with blanks to get an error back what that info.
r = String.fromCharCode(0x13, 0x00, 0x00, 0x00, 0x04);
r += common.IntToStrX(obj.args.user.length + authurl.length + 8);
r += String.fromCharCode(obj.args.user.length);
r += obj.args.user;
r += String.fromCharCode(0x00, 0x00, authurl.length);
r += authurl;
r += String.fromCharCode(0x00, 0x00, 0x00, 0x00);
obj.ws.acc = obj.ws.acc.substring(9 + l); // Don't relay the original message
return r;
}
}
r = obj.ws.acc.substring(0, 9 + l);
obj.ws.acc = obj.ws.acc.substring(9 + l);
return r;
}
default: {
obj.ws.error = true;
}
}
}
return '';
};
// Compute the MD5 digest hash for a set of values
obj.ComputeDigesthash = function (username, password, realm, method, path, qop, nonce, nc, cnonce) {
var ha1 = crypto.createHash('md5').update(username + ':' + realm + ':' + password).digest('hex');
var ha2 = crypto.createHash('md5').update(method + ':' + path).digest('hex');
return crypto.createHash('md5').update(ha1 + ':' + nonce + ':' + nc + ':' + cnonce + ':' + qop + ':' + ha2).digest('hex');
};
return obj;
};