English
资源说明：http ssh relay for use with chromium hterm session
goatse
======
http ssh relay for use with chromium hterm session
This is an attempt to reverse-engineer googles javascript code for their http-ssh relays for the purpose of
creating my own ssh relay. The relays themselves are proprietary, however the connection scripts are not.
Below is the code from nassh_google_relay.js
1 // Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 'use strict';
6
7 lib.rtdep('lib.f');
8
9 /**
10 * This file contains the support required to make connections to Google's
11 * HTTP-to-SSH relay.
12 *
13 * See Also: nassh_stream_google_relay.js, which defines the hterm stream class
14 * for this relay mechanism.
15 *
16 * The relay is only available within Google at the moment. If you'd like
17 * to create one of your own though, you could follow the same conventions
18 * and have a client ready to go.
19 *
20 * The connection looks like this...
21 *
22 * +------+ +-------+ +---------------+
23 * | USER | | PROXY | | COOKIE_SERVER |
24 * +------+ +-------+ +---------------+
25 *
26 * +-----------+
27 * | SSH_RELAY |
28 * +-----------+
29 *
30 * 1. User specifies that they'd like to make their ssh connection through a
31 * web server. In this code, that web server is called the 'proxy', since
32 * it happens to be an HTTP proxy.
33 *
34 * 2. We redirect to the 'http://HOST:8022/cookie?ext=RETURN_TO'.
35 *
36 * HOST is the user-specified hostname for the proxy. Port 8022 on the
37 * proxy is assumed to be the cookie server.
38 *
39 * RETURN_TO is the location that the cookie server should redirect to
40 * when the cookie server is satisfied.
41 *
42 * This connects us to the 'cookie server', which can initiate a
43 * single-sign-on flow if necessary. It's also responsible for telling us
44 * which SSH_RELAY server we should talk to for the actual ssh read/write
45 * operations.
46 *
47 * 3. When the cookie server is done with its business it redirects to
48 * /html/google_relay.html#USER@RELAY_HOST.
49 *
50 * The RELAY_HOST is the host that we should use as the socket relay.
51 * This allows the cookie server to choose a relay server from a
52 * pool of hosts. This is *just* the host name, it's up to clients to
53 * know the uri scheme and port number.
54 *
55 * The RELAY_HOST is expected to respond to requests for /proxy, /write,
56 * and /read.
57 *
58 * 4. We send a request to /proxy, which establishes the ssh session with
59 * a remote host.
60 *
61 * 5. We establish a hanging GET on /read. If the read completes with a
62 * HTTP 200 OK then we consider the response entity as web-safe base 64
63 * encoded data. If the read completes with an HTTP 401 GONE, we assume
64 * the relay has discarded the ssh session. Any other responses are
65 * ignored. The /read request is reestablished for anything other than
66 * 401.
67 *
68 * 6. Writes are queued up and sent to /write.
69 */
70
71 nassh.GoogleRelay = function(io, proxy, options) {
72 this.io = io;
73 this.proxy = proxy;
74 this.useSecure = options.search('--use-ssl') != -1;
75 this.useWebsocket = !(options.search('--use-xhr') != -1);
76 this.relayServer = null;
77 this.relayServerSocket = null;
78 };
79
80 /**
81 * The pattern for the cookie server's url.
82 */
83 nassh.GoogleRelay.prototype.cookieServerPattern =
84 '%(protocol)://%(host):8022/cookie?ext=%encodeURIComponent(return_to)' +
85 '&path=html/nassh_google_relay.html';
86
87 /**
88 * The pattern for XHR relay server's url.
89 *
90 * We'll be appending 'proxy', 'read' and 'write' to this as necessary.
91 */
92 nassh.GoogleRelay.prototype.relayServerPattern =
93 '%(protocol)://%(host):8023/';
94
95 /**
96 * The pattern for WebSocket relay server's url.
97 */
98 nassh.GoogleRelay.prototype.relayServerSocketPattern =
99 '%(protocol)://%(host):8022/';
100
101 nassh.GoogleRelay.prototype.redirect = function(opt_resumePath) {
102 var resumePath = opt_resumePath ||
103 document.location.href.substr(document.location.origin.length);
104
105 // Save off our destination in session storage before we leave for the
106 // proxy page.
107 sessionStorage.setItem('googleRelay.resumePath', resumePath);
108
109 document.location = lib.f.replaceVars(
110 this.cookieServerPattern,
111 { host: this.proxy,
112 protocol: this.useSecure ? 'https' : 'http',
113 // This returns us to nassh_google_relay.html so we can pick the relay
114 // host out of the reply. From there we continue on to the resumePath.
115 return_to: document.location.host
116 });
117 };
118
119 /**
120 * Initialize this relay object.
121 *
122 * If we haven't just come back from the cookie server, then this function
123 * will redirect to the cookie server and return false.
124 *
125 * If we have just come back from the cookie server, then we'll return true.
126 */
127 nassh.GoogleRelay.prototype.init = function(opt_resumePath) {
128 var resumePath = opt_resumePath ||
129 document.location.href.substr(document.location.origin.length);
130
131 // This session storage item is created by /html/nassh_google_relay.html
132 // if we succeed at finding a relay host.
133 var relayHost = sessionStorage.getItem('googleRelay.relayHost');
134 if (relayHost) {
135 var expectedResumePath =
136 sessionStorage.getItem('googleRelay.resumePath');
137 if (expectedResumePath == resumePath) {
138 var protocol = this.useSecure ? 'https' : 'http';
139 var pattern = this.useWebsocket ? this.relayServerSocketPattern :
140 this.relayServerPattern;
141 this.relayServer = lib.f.replaceVars(pattern,
142 {host: relayHost, protocol: protocol});
143 if (this.useWebsocket) {
144 protocol = this.useSecure ? 'wss' : 'ws';
145 this.relayServerSocket = lib.f.replaceVars(pattern,
146 {host: relayHost, protocol: protocol});
147 }
148 } else {
149 // If everything is ok, this should be the second time we've been asked
150 // to do the same init. (The first time would have redirected.) If this
151 // init specifies a different resumePath, then something is probably
152 // wrong.
153 console.warn('Destination mismatch: ' + expectedResumePath + ' != ' +
154 resumePath);
155 this.relayServer = null;
156 }
157 }
158
159 sessionStorage.removeItem('googleRelay.relayHost');
160 sessionStorage.removeItem('googleRelay.resumePath');
161
162 if (this.relayServer)
163 return true;
164
165 return false;
166 };
167
168 /**
169 * Return an nassh.Stream object that will handle the socket stream
170 * for this relay.
171 */
172 nassh.GoogleRelay.prototype.openSocket = function(fd, host, port, onOpen) {
173 var streamClass = this.useWebsocket ? nassh.Stream.GoogleRelayWS :
174 nassh.Stream.GoogleRelayXHR;
175 return nassh.Stream.openStream(streamClass,
176 fd, {relay: this, host: host, port: port}, onOpen);
177 };
本源码包内暂不包含可直接显示的源代码文件，请下载源码包。
