sni-passthrough

A minimalistic SNI pass-through proxy. Not a full featured TLS termination or load-balancer!

Usage

require('sni-passthrough').createServer({
    sni: {
        'sni-1.com': '127.0.0.1:444',
        'sni-2.com': '> 127.0.0.1:445',
        'sni-3.com': '[::1]:446',
        '*':         '127.0.0.1:444'
    }
})
.listen(443)

API

createServer(opts) => net.Server

opts.sni

Either an object or a function

The object: hostname => destination mapping
destination is a "host:port" string, port must NOT be omitted.
Wildcard and RegExp are not supported.
Use destination null to blacklist a domain name.
Prepend > to destination to mark a compatible backend. Use hostname '*' to designate a fallback.

The function: (hostname) => forwardFunc(conn, buf) || undefined
If SNI is not sent, hostname will be null
If function returns undefined, incoming connection is dropped.
Use this to implement load-balancing or complicated logic.
forwardFunc should connect and pipe conn to backend.

opts will be passed to net.createServer, you can specify additional options

Remote peer IP address

Use > to mark a compatible backend destination.
In this case, remote peer's information is injected before piping.
For example, see sni-passthrough-backend

Do not specify this flag for incompatible backend!

Maybe a X-Forwarded-For TLS extension? 🙃

Performance

On loopback, with my 2015 MBP @ 2.4Ghz, I was able to achieve:

• ~8Ghz thorough-put
• ~1800 QPS for a single 2000 QPS backend (~10% loss, wrk -c100)

Testing

1. Generate key, self-sign certificate
2. Put them at key.pem, cert.pem
3. In terminal, run mocha

License

MIT