/** * @description MeshCentral Intel(R) AMT Interceptor * @author Ylian Saint-Hilaire * @copyright Intel Corporation 2018 * @license Apache-2.0 * @version v0.0.3 */ 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; // 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 data; } // Process data coming from AMT in the accumulator obj.processAmtDataEx = function () { if (obj.amt.mode == 0) { // Header Mode // Decode the HTTP header var 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 (var 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 var r = obj.amt.directive.join(' ') + '\r\n'; for (var 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; var 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 var 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) var 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 var 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 var r = obj.amt.acc; obj.amt.acc = ""; return r; } return ""; } // Process data coming from the Browser obj.processBrowserData = function (data) { obj.ws.acc += data; // 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 data; } // Process data coming from the Browser in the accumulator obj.processBrowserDataEx = function () { if (obj.ws.mode == 0) { // Header Mode // Decode the HTTP header var 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 (var 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]); 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 var r = obj.ws.directive.join(' ') + '\r\n'; for (var 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; var 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 var 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 var 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) var 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 var 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 var 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) { obj.amt.acc += data; // 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 data; } // Process data coming from AMT in the accumulator obj.processAmtDataEx = function () { 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 ""; var 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 succesful, go to direct relay mode in both directions. obj.ws.direct = true; obj.amt.direct = true; } var 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) { obj.ws.acc += data; // 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 data; } // Process data coming from the Browser in the accumulator obj.processBrowserDataEx = function () { 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 ""; var 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 ""; var 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 var 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. var 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; } } var 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 ""; } } } 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; }