sslh accepts connections on specified ports, and forwards
them further based on tests performed on the first data
packet sent by the remote client.
Probes for HTTP, TLS/SSL (including SNI and ALPN), SSH, OpenVPN, tinc, XMPP, SOCKS5, are implemented, and any other protocol that can be tested using a regular expression, can be recognised. A typical use case is to allow serving several services on port 443 (e.g. to connect to SSH from inside a corporate firewall, which almost never block port 443) while still serving HTTPS on that port.
Hence sslh acts as a protocol demultiplexer, or a
switchboard. With the SNI and ALPN probe, it makes a good
front-end to a virtual host farm hosted behind a single IP
address.
sslh has the bells and whistles expected from a mature
daemon: privilege and capabilities dropping, inetd support,
systemd support, transparent proxying,
chroot, logging, IPv4 and IPv6, a fork-based and a
select-based model, and more.
Please refer to the install guide.
Please refer to the configuration guide.
You can subscribe to the sslh mailing list here:
https://lists.rutschle.net/mailman/listinfo/sslh
This mailing list should be used for discussion, feature requests, and will be the preferred channel for announcements.
Of course, check the FAQ first!