1+ /*
2+ relay-proxy.js: http proxy for node.js
3+
4+ Copyright (c) 2010 Nathan Ridley
5+
6+ Permission is hereby granted, free of charge, to any person obtaining
7+ a copy of this software and associated documentation files (the
8+ "Software"), to deal in the Software without restriction, including
9+ without limitation the rights to use, copy, modify, merge, publish,
10+ distribute, sublicense, and/or sell copies of the Software, and to
11+ permit persons to whom the Software is furnished to do so, subject to
12+ the following conditions:
13+
14+ The above copyright notice and this permission notice shall be
15+ included in all copies or substantial portions of the Software.
16+
17+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20+ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21+ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22+ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23+ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
24+
25+ */
26+
27+ var httpProxy = require ( 'http-proxy' ) ,
28+ net = require ( 'net' ) ,
29+ http = require ( 'http' ) ,
30+ util = require ( 'util' ) ;
31+
32+ function RelayProxy ( ) {
33+
34+ var authHandler = function defaultAuthHandler ( req , username , password , callback ) {
35+ // @arg 1: error object
36+ // @arg 2: true if authorized, otherwise false
37+ callback ( null , true ) ;
38+ }
39+
40+ var proxySelector = function defaultProxySelector ( req , username , callback ) {
41+ // @arg 1: error object
42+ // @arg 2: a proxy options object, or false to decline the request,
43+ // or null to forward directly to the remote host
44+ // options: {
45+ // host: 'x.x.x.x',
46+ // port: 9999,
47+ // username: 'username', // optional
48+ // password: 'password' // optional
49+ // }
50+ callback ( null , null ) ;
51+ }
52+
53+ function getAuth ( req ) {
54+
55+ var authHeader = req . headers [ 'proxy-authorization' ] ;
56+ if ( authHeader ) {
57+ var authMatch = ( new Buffer ( authHeader . substr ( 6 ) , 'base64' ) ) . toString ( ) . match ( / ^ ( [ ^ : ] * ) : ( .* ) $ / ) ;
58+ if ( authMatch && authMatch [ 1 ] && authMatch [ 2 ] ) {
59+ return {
60+ username : authMatch [ 1 ] ,
61+ password : authMatch [ 2 ]
62+ } ;
63+ }
64+ }
65+ return null ;
66+ }
67+
68+ function createAuthHeader ( username , password ) {
69+ return 'Basic ' + new Buffer ( username + ':' + password ) . toString ( 'base64' ) ;
70+ }
71+
72+ function getRemoteProxy ( req , callback ) {
73+
74+ var auth = getAuth ( req ) || { } ;
75+ authHandler ( req , auth . username , auth . password , function onAuthHandlerCallback ( err , authorized ) {
76+
77+ if ( ! authorized ) {
78+ req . connection . end ( 'HTTP/1.0 407 Proxy authentication required\r\nProxy-authenticate: Basic realm="remotehost"\r\n\r\n' ) ;
79+ callback ( new Error ( 'Proxy authorization not supplied (407 response sent)' ) )
80+ return ;
81+ } ;
82+
83+ proxySelector ( req , auth . username , function onProxySelectorCallback ( err , options ) {
84+
85+ if ( options === false ) {
86+ req . connection . end ( 'HTTP/1.0 429 Too Many Requests\r\n\r\nNo proxy available to service request' ) ;
87+ callback ( new Error ( 'No remote proxies available (429 response sent)' ) ) ;
88+ return ;
89+ }
90+
91+ callback ( null , options ) ;
92+ } ) ;
93+
94+ } ) ;
95+ }
96+
97+ function onHttpRequest ( req , res , proxy ) {
98+
99+ var buffer = httpProxy . buffer ( req ) ;
100+
101+ console . log ( 'HTTP --> ' + req . url ) ;
102+
103+ getRemoteProxy ( req , function ( err , remoteProxy ) {
104+
105+ if ( err ) {
106+ console . log ( err . message ) ;
107+ return ;
108+ }
109+
110+ if ( ! remoteProxy ) {
111+ var parts = req . headers . host . split ( ':' ) ;
112+ proxy . proxyRequest ( req , res , {
113+ host : parts [ 0 ] ,
114+ port : parts [ 1 ] || 80
115+ } ) ;
116+ return ;
117+ }
118+
119+ req . path = req . url ;
120+ if ( remoteProxy . username && remoteProxy . password )
121+ req . headers [ 'proxy-authorization' ] = createAuthHeader ( remoteProxy . username , remoteProxy . password ) ;
122+ var options = {
123+ host : remoteProxy . host ,
124+ port : remoteProxy . port ,
125+ buffer : buffer
126+ }
127+ proxy . proxyRequest ( req , res , options ) ;
128+ } ) ;
129+ }
130+
131+ function onHttpsRequest ( req , socket , head ) {
132+
133+ console . log ( 'HTTPS --> ' + req . url ) ;
134+
135+ getRemoteProxy ( req , function ( err , remoteProxy ) {
136+
137+ if ( err ) {
138+ console . log ( err . message ) ;
139+ return ;
140+ }
141+
142+ if ( ! remoteProxy ) {
143+ var parts = req . url . split ( ':' ) ;
144+ var conn = net . connect ( parts [ 1 ] , parts [ 0 ] , function ( ) {
145+ socket . write ( 'HTTP/1.1 200 OK\r\n\r\n' ) ;
146+ conn . pipe ( socket ) ;
147+ socket . pipe ( conn ) ;
148+ } ) ;
149+ return ;
150+ }
151+
152+ var conn = net . connect ( remoteProxy . port , remoteProxy . host , function ( ) {
153+
154+ var headers
155+ = 'CONNECT ' + req . url + ' HTTP/1.1\r\n'
156+ + 'Proxy-Authorization: ' + createAuthHeader ( remoteProxy . username , remoteProxy . password ) + '\r\n\r\n' ;
157+ conn . write ( headers ) ;
158+
159+ } ) . once ( 'data' , function ( buffer ) {
160+
161+ var ok = / ^ H T T P \/ 1 .[ 0 1 ] 2 0 0 / i. test ( buffer . toString ( 'utf8' ) ) ;
162+ if ( ! ok )
163+ socket . end ( 'HTTP/1.1 401 Unauthorized\r\n\r\nUpstream proxy rejected the request' ) ;
164+ else {
165+ socket . write ( 'HTTP/1.1 200 OK\r\n\r\n' ) ;
166+ socket . pipe ( conn ) ;
167+ conn . pipe ( socket ) ;
168+ }
169+ } ) ;
170+ } )
171+ }
172+
173+ this . authorize = function authorize ( handler ) {
174+ authHandler = handler ;
175+ }
176+
177+ this . selectForwardProxy = function selectForwardProxy ( handler ) {
178+ proxySelector = handler ;
179+ }
180+
181+ this . listen = function listen ( port ) {
182+ port || ( port = 3333 ) ;
183+ this . server = httpProxy
184+ . createServer ( onHttpRequest )
185+ . on ( 'connect' , onHttpsRequest )
186+ . listen ( port ) ;
187+
188+ console . log ( 'Proxy server now listening on port ' + port + '.' ) ;
189+ }
190+ }
191+
192+ module . exports = RelayProxy ;
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