Deputy

A web proxy built on Cowboy and Gun.

It does HTTP proxy calls for plaintext HTTP and accepts the HTTP CONNECT method to establish a TCP tunnel for TLS and other protocols.

+---------+  Plaintext HTTP/1.1 or   +-------+  Plaintext HTTP/1.1  +--------+
|         |    HTTP/2 (port 8080)    |       |   (or HTTP/2)        |        |
|         |------------------------->|       |--------------------->|        |
| Browser |                          | Proxy |                      | Origin |
|         | HTTP/1.1 or HTTP/2 over  |       |  Opaque TCP tunnel   |        |
|         |  TLS (port 8443)         |       | (TLS or other data)  |        |
|         |------------------------->|       |--------------------->|        |
|         |                          |       |                      |        |
+---------+                          +-------+                      +--------+

Status

This is proxy is created for testing the CONNECT functionality in Cowboy, which is under development.

• Configuration is hard-coded. Change the code and recomplile to change anything.
• HTTP/2 over plaintext TCP (proxy to origin) is not enabled by default.
• Most browsers use HTTP/2 over TLS only. For connections without TLS, they use HTTP/1.1. The connection to the proxy is what matters.

Usage

Start it by running make; make shell and then type application:ensure_all_started(deputy). in the Erlang shell. Then configure a browser to use localhost and port 8080 as HTTP proxy.

TLS

If you want to connect to the proxy using TLS, configure the browser to accept the self-signed certificate which is generated by make and configure the browser to use port 8443 and TLS for the proxy. In Firefox, you need to use a PAC file for this.

1. Import priv/certs/localhost-ca.crt to your browser's trusted certificate authorities. In Firefox, this is under Privacy & Security -> Certificates -> Authorities.
2. Use priv/https-localhost.pac as the autmatic proxy configuation file. In Firefox: General -> Network Settings -> Automatic proxy configuration URL. You may need put in a file URI, like file:///home/viktor/repos/deputy/priv/https-localhost.pac.