Move tunnel logic into separate module

lib/helpers.js

@@ -46,10 +46,19 @@ function toBase64 (str) {
   return (new Buffer(str || '', 'utf8')).toString('base64')
 }
 
+function copy (obj) {
+  var o = {}
+  Object.keys(obj).forEach(function (i) {
+    o[i] = obj[i]
+  })
+  return o
+}
+
 exports.isFunction            = isFunction
 exports.paramsHaveRequestBody = paramsHaveRequestBody
 exports.safeStringify         = safeStringify
 exports.md5                   = md5
 exports.isReadStream          = isReadStream
 exports.toBase64              = toBase64
+exports.copy                  = copy
 exports.defer                 = deferMethod()

lib/tunnel.js

@@ -0,0 +1,183 @@
+'use strict'
+
+var url = require('url')
+  , tunnel = require('tunnel-agent')
+
+var defaultProxyHeaderWhiteList = [
+  'accept',
+  'accept-charset',
+  'accept-encoding',
+  'accept-language',
+  'accept-ranges',
+  'cache-control',
+  'content-encoding',
+  'content-language',
+  'content-length',
+  'content-location',
+  'content-md5',
+  'content-range',
+  'content-type',
+  'connection',
+  'date',
+  'expect',
+  'max-forwards',
+  'pragma',
+  'referer',
+  'te',
+  'transfer-encoding',
+  'user-agent',
+  'via'
+]
+
+var defaultProxyHeaderExclusiveList = [
+  'proxy-authorization'
+]
+
+function constructProxyHost(uriObject) {
+  var port = uriObject.portA
+    , protocol = uriObject.protocol
+    , proxyHost = uriObject.hostname + ':'
+
+  if (port) {
+    proxyHost += port
+  } else if (protocol === 'https:') {
+    proxyHost += '443'
+  } else {
+    proxyHost += '80'
+  }
+
+  return proxyHost
+}
+
+function constructProxyHeaderWhiteList(headers, proxyHeaderWhiteList) {
+  var whiteList = proxyHeaderWhiteList
+    .reduce(function (set, header) {
+      set[header.toLowerCase()] = true
+      return set
+    }, {})
+
+  return Object.keys(headers)
+    .filter(function (header) {
+      return whiteList[header.toLowerCase()]
+    })
+    .reduce(function (set, header) {
+      set[header] = headers[header]
+      return set
+    }, {})
+}
+
+function constructTunnelOptions (request, proxyHeaders) {
+  var proxy = request.proxy
+
+  var tunnelOptions = {
+    proxy : {
+      host      : proxy.hostname,
+      port      : +proxy.port,
+      proxyAuth : proxy.auth,
+      headers   : proxyHeaders
+    },
+    headers            : request.headers,
+    ca                 : request.ca,
+    cert               : request.cert,
+    key                : request.key,
+    passphrase         : request.passphrase,
+    pfx                : request.pfx,
+    ciphers            : request.ciphers,
+    rejectUnauthorized : request.rejectUnauthorized,
+    secureOptions      : request.secureOptions,
+    secureProtocol     : request.secureProtocol
+  }
+
+  return tunnelOptions
+}
+
+function constructTunnelFnName(uri, proxy) {
+  var uriProtocol = (uri.protocol === 'https:' ? 'https' : 'http')
+  var proxyProtocol = (proxy.protocol === 'https:' ? 'Https' : 'Http')
+  return [uriProtocol, proxyProtocol].join('Over')
+}
+
+function getTunnelFn(request) {
+  var uri = request.uri
+  var proxy = request.proxy
+  var tunnelFnName = constructTunnelFnName(uri, proxy)
+  return tunnel[tunnelFnName]
+}
+
+
+function Tunnel (request) {
+  this.request = request
+  this.proxyHeaderWhiteList = defaultProxyHeaderWhiteList
+  this.proxyHeaderExclusiveList = []
+}
+
+Tunnel.prototype.isEnabled = function (options) {
+  var request = this.request
+  // Tunnel HTTPS by default, or if a previous request in the redirect chain
+  // was tunneled.  Allow the user to override this setting.
+
+  // If self.tunnel is already set (because this is a redirect), use the
+  // existing value.
+  if (typeof request.tunnel !== 'undefined') {
+    return request.tunnel
+  }
+
+  // If options.tunnel is set (the user specified a value), use it.
+  if (typeof options.tunnel !== 'undefined') {
+    return options.tunnel
+  }
+
+  // If the destination is HTTPS, tunnel.
+  if (request.uri.protocol === 'https:') {
+    return true
+  }
+
+  // Otherwise, leave tunnel unset, because if a later request in the redirect
+  // chain is HTTPS then that request (and any subsequent ones) should be
+  // tunneled.
+  return undefined
+}
+
+Tunnel.prototype.setup = function (options) {
+  var self = this
+    , request = self.request
+
+  options = options || {}
+
+  if (typeof request.proxy === 'string') {
+    request.proxy = url.parse(request.proxy)
+  }
+
+  if (!request.proxy || !request.tunnel) {
+    return false
+  }
+
+  // Setup Proxy Header Exclusive List and White List
+  if (options.proxyHeaderWhiteList) {
+    self.proxyHeaderWhiteList = options.proxyHeaderWhiteList
+  }
+  if (options.proxyHeaderExclusiveList) {
+    self.proxyHeaderExclusiveList = options.proxyHeaderExclusiveList
+  }
+
+  var proxyHeaderExclusiveList = self.proxyHeaderExclusiveList.concat(defaultProxyHeaderExclusiveList)
+  var proxyHeaderWhiteList = self.proxyHeaderWhiteList.concat(proxyHeaderExclusiveList)
+
+  // Setup Proxy Headers and Proxy Headers Host
+  // Only send the Proxy White Listed Header names
+  var proxyHeaders = constructProxyHeaderWhiteList(request.headers, proxyHeaderWhiteList)
+  proxyHeaders.host = constructProxyHost(request.uri)
+
+  proxyHeaderExclusiveList.forEach(request.removeHeader, request)
+
+  // Set Agent from Tunnel Data
+  var tunnelFn = getTunnelFn(request)
+  var tunnelOptions = constructTunnelOptions(request, proxyHeaders)
+  request.agent = tunnelFn(tunnelOptions)
+
+  return true
+}
+
+Tunnel.defaultProxyHeaderWhiteList = defaultProxyHeaderWhiteList
+Tunnel.defaultProxyHeaderExclusiveList = defaultProxyHeaderExclusiveList
+exports.Tunnel = Tunnel