Websockets (SIP) test server

A very simple Websocket server written in Go, meant for use with WebRTC clients only.

Main goal and motivation for this repo is having simple service to test load balancing and scaling scenarios with WebRTC clients. HTTP/1.1 upgrade request will negotiate websocket connection and switch to SIP subprotocol. Any subsequent requests from WebRTC clients will be responded with 200 OK - it assumes that only REGISTER is sent, so the clients will be successfully registered and then stay idle.

Note: any request from websocket client will be responded with text based SIP 200 OK response

• Proxy protocol supported
• Has SSL/TLS support with self-signed certs.

To enable proxy protocol support set environment variable PROXYP to any value. The default WS port is 8080, if you need to change it set new port to PORT env variable.

SSL/TLS/WSS

The default encrypted port is 8443, if you need to change it set new port to SSLPORT env variable. Self signed ertificate is generated for wss.local domain If you'd like to use your own, you can clone this repo, gen your own cert, and rebuild the bin/image.

How to create an HTTPS certificate for localhost domains

This focuses on generating the certificates for loading local virtual hosts hosted on your computer, for development only.

Certificate authority (CA)

Generate RootCA.pem, RootCA.key & RootCA.crt:

openssl req -x509 -nodes -new -sha256 -days 1024 -newkey rsa:2048 -keyout RootCA.key -out RootCA.pem -subj "/C=US/CN=Example-Root-CA"
openssl x509 -outform pem -in RootCA.pem -out RootCA.crt

Note that Example-Root-CA is an example, you can customize the name.

Domain name certificate

Let's say you have two domains fake1.local and fake2.local that are hosted on your local machine for development (using the hosts file to point them to 127.0.0.1).

First, create a file domains.ext that lists all your local domains:

authorityKeyIdentifier=keyid,issuer
basicConstraints=CA:FALSE
keyUsage = digitalSignature, nonRepudiation, keyEncipherment, dataEncipherment
subjectAltName = @alt_names
[alt_names]
DNS.1 = localhost
DNS.2 = fake1.local
DNS.3 = fake2.local

Generate localhost.key, localhost.csr, and localhost.crt:

openssl req -new -nodes -newkey rsa:2048 -keyout localhost.key -out localhost.csr -subj "/C=US/ST=YourState/L=YourCity/O=Example-Certificates/CN=localhost.local"
openssl x509 -req -sha256 -days 1024 -in localhost.csr -CA RootCA.pem -CAkey RootCA.key -CAcreateserial -extfile domains.ext -out localhost.crt

Note that the country / state / city / name in the first command can be customized.

REGISTER example

"REGISTER sips:ss2.biloxi.example.com SIP/2.0\r\n" +
"Via: SIP/2.0/TLS client.biloxi.example.com:5061;branch=z9hG4bKnashds7\r\n" +
"Max-Forwards: 70\r\n" +
"From: Bob <sips:bob@biloxi.example.com>;tag=a73kszlfl\r\n" +
"To: Bob <sips:bob@biloxi.example.com>\r\n" +
"Call-ID: 1j9FpLxk3uxtm8tn@biloxi.example.com\r\n" +
"CSeq: 1 REGISTER\r\n" +
"Contact: <sips:bob@client.biloxi.example.com>\r\n" +
"Content-Length: 0\r\n\r\n"

Example Output

10.10.10.1:58198 | GET /
10.10.10.1:58198 | upgraded to websocket
10.10.10.1:58198 | txt | REGISTER sip:sip.sample.com SIP/2.0
Via: SIP/2.0/WSS 1dr8h0krkpml.invalid;branch=z9hG4bK5228023
Max-Forwards: 70
To: "Gob Bleuth" <sip:sipuser_1@sip.sample.com>
From: "Gob Bleuth" <sip:sipuser_1@sip.sample.com>;tag=n8dabtdci5
Call-ID: rodpg9i3i0dhgqpgmsfk5n
CSeq: 81 REGISTER
Contact: <sip:bqiqbcot@1dr8h0krkpml.invalid;transport=ws>;reg-id=1;+sip.instance="<urn:uuid:9e481b70-4eed-4799-b48f-a53f1d3875a7>";expires=300
Allow: ACK,CANCEL,INVITE,MESSAGE,BYE,OPTIONS,INFO,NOTIFY,REFER
Supported: path, gruu, outbound
User-Agent: SIP.js/0.7.8
Content-Length: 0


SIP/2.0 200 OK
Via: SIP/2.0/WSS 1dr8h0krkpml.invalid;branch=z9hG4bK5228023;received=10.10.10.1
From: <sip:sipuser_1@sip.sample.com>;tag=n8dabtdci5
To: <sip:sipuser_1@sip.sample.com>;tag=37GkEhwl6
Call-ID: rodpg9i3i0dhgqpgmsfk5n
CSeq: 81 REGISTER
Contact: <sip:bqiqbcot@1dr8h0krkpml.invalid;transport=ws>;reg-id=1;+sip.instance="<urn:uuid:9e481b70-4eed-4799-b48f-a53f1d3875a7>";expires=300
Content-Length: 0