1Crypt/OICQ version 1.0 2===================== 3 4 This module implements the cipher used by OICQ instant messaging protocol, 5used by Tencent Technology Limited, China. 6 7INSTALLATION 8 9To install this module type the following: 10 11 perl Makefile.PL 12 make test 13 su 14 make install 15 16DEPENDENCIES 17 18None 19 20ACKNOWLEDGEMENT 21 22FreeOICQ developers reverse-engineered Tencent's Win32 client binaries and 23published their discovery on http://sourceforge.net/projects/foicq/. Among 24their codes are segments of assembly code for the OICQ cipher and login key 25generation. 26 27I identified the algorithm for login key generation to be MD5. 28 29Chen Peng reverse-engineered the rest of assembly codes created by FreeOICQ and 30identified the core cipher used by OICQ to be a weakened version of TEA, Tiny 31Encryption Algorithm. 32 33TEA was invented by David Wheeler and Roger Needham at Cambridge University. 34They recommend using 32 rounds. OICQ only uses 16 rounds. 35 36COPYRIGHT AND LICENCE 37 38Copyright (c) 2003 Shufeng Tan. All rights reserved. 39 40This package is free software and is provided "as is" without express 41or implied warranty. It may be used, redistributed and/or modified 42under the terms of the Perl Artistic License (see 43http://www.perl.com/perl/misc/Artistic.html) 44 45