Simple Repeater

stone version 2.4

Copyright(c)1995-2021 by Hiroaki Sengoku

Stone is a TCP/IP repeater in the application layer. It repeats TCP and UDP from inside to outside of a firewall, or from outside to inside.

Stone has following features:

1. Stone supports Win32.
Formerly, UNIX machines are used as firewalls, but recently WindowsNT machines are used, too. You can easily run Stone on WindowsNT/2000/XP and Windows95/98/ME. Of course, available on Linux, FreeBSD, BSD/OS, SunOS, Solaris, HP-UX and so on.
2. Simple.
Stone's source code is only 10000 lines long (written in C language), so you can minimize the risk of security holes.
3. Stone supports SSL.
Using OpenSSL, stone can encrypt/decrypt. Client verifications, and server verifications are also supported. Stone can send a substring of the subject of the certificate to the destination.
4. Stone is a http proxy.
Stone can also be a tiny http proxy.
5. POP -> APOP conversion.
With stone and a mailer that does not support APOP, you can access to an APOP server. The MD5 program is needed.
6. Stone supports IPv6.
Stone can convert IP and IPv6 each other. With stone, you can use IP-only software on IPv6 network.

I wrote articles explaining stone (written in Japanese) in my Nikkei Linux Serial.

I writes a stone development diary (written in Japanese). I'll write useful hints for using the CVS repository.

Official Release (02/15/19)

Snapshot (02/15/19)


To join, send mail to (the message body may be null). If you want to specify your address, send mail to (in the case your address is name@host.domain). You'll receive the confirmation mail, so reply to it.


stone outer:telnet 10023
stone outer:domain/udp domain/udp
stone outer:ntp/udp ntp/udp
stone localhost:http 443/ssl
stone localhost:telnet 10023/ssl
stone proxy 8080
stone outer:pop/apop pop
stone fwall:8080/http 10023 'POST http://outer:8023 HTTP/1.0'
stone localhost:telnet 8023/http
stone fwall:8080/proxy 9080 'Proxy-Authorization: Basic c2VuZ29rdTpoaXJvYWtp'
#2939 Hiroaki Sengoku <>

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