Implementation of an offline dictionary attack against WPA/WPA2 networks using PSK-based authentication (e.g. Many enterprise networks deploy PSK-based authentication mechanisms for WPA/WPA2 since it is much easier than establishing the necessary RADIUS, supplicant and certificate authority architecture needed for WPA-Enterprise authentication. Cowpatty can implement an accelerated attack if a precomputed PMK file is available for the SSID that is being assessed. News July 03 2009 Posted a new version of coWPAtty (4.6) with the following changes: • Fixed buffer overflow on modern OpenSSL systems when caching hashed hmac-sha1 ipad and opad values (just stupidity on my part, not an exploitable vulnerability); • Corrected compile warnings with modern gcc. Special thanks to Kevin Kestinggolrer, Philipp Schroedel, Max Moser, Nathan Grennan, Jason Franks and Michal Knobel for their help and support. June 04 2009 Posted a new version of coWPAtty (4.5) with the following changes: • Hashfile can be read from STDIN (thanks Thomas d’Otreppe); • More liberal collection of handshake information to make coWPAtty work with AP’s that do not implement the 4-way handshake exactly to the specification.