my development environment is OpenBSD.

OpenBSD users should set EVENT_NOKQUEUE=yes in their shell to ensure libevent works properly.

jscan features

jscan is an active SYN scanner:
$ sudo jscan -t active -s -d -i fxp0 -f compat/pf.os
scan started, type is active, listening on fxp0                          3x:Linux 2.0.3x         daytime     13/tcp                          3x:Linux 2.0.3x             ssh     22/tcp                          3x:Linux 2.0.3x            time     37/tcp                          3x:Linux 2.0.3x           whois     43/tcp                          3x:Linux 2.0.3x          domain     53/tcp                          3x:Linux 2.0.3x          sunrpc    111/tcp                          3x:Linux 2.0.3x            auth    113/tcp                          3x:Linux 2.0.3x             bgp    179/tcp
scan completed. total execution time was 70 seconds.
jscan is a passive TCP scanner, too!
$ sudo jscan -t passive -i fxp0 -f compat/pf.os
scan started, type is passive, listening on fxp0                                unknown             www     80/tcp                     :FreeBSD 4.6-4.8             www     80/tcp
and .. yes. you can run two instances of jscan and have one send the packets and one listen for the replies. decoupled scanning ...


this code is NOT suitable for real world use, it contains a number of flaws which make it easy to detect scanning and fingerprint the scanner. it is up to the reader to improve upon this codebase.


jscan-0.3.2.tar.gz 21 sep 2004