enc_aes

  AES Strong Encryption Plugin for Back Orifice 2000
  
  Copyright (C) 1999-2001, Daniel Roethlisberger
  
  Version 1.0 DEVELOPERS BETA 3, January 2nd, 2001
  
  
  ==========================================
   THIS IS A DEVELOPERS' ONLY BETA RELEASE.
   PLEASE DO NOT REDISTRIBUTE THIS VERSION.
  ==========================================



------[ Description ]---------------------------------------------------

  This is a plugin for the remote administration suite Back Orifice
  2000 (BO2K) from the one and only, the Cult of the Dead Cow (cDc).
  Released at DEFCON 7, BO2K was subject to massive hype even weeks
  before the actual release of it.
  
  This plugin adds Advanced Encryption Standard (AES) encryption in
  CBC mode capability to your BO2K. You can trade off security versus
  speed by choosing your keysize individually.
  
  If you want strong, flexible and fast encryption, you should go for
  this one. It is of course internationally available.



------[ Security Considerations ]---------------------------------------

  AES offers the strongest encryption power known to Back Orifice
  2000. In key size terms, this implementation of AES uses user keys
  of up to 512 bits length (Comparison: RC6 384 bits,
  Serpent/CAST-256 256 bits, TripleDES 168 bits, IDEA 128 bits).
  Of course keysize alone doesn't make an algorithm secure.
  As far as we can tell today, AES -is- secure. It has been
  extensively cryptanalized during the last couple of years by the
  worlds leading crypto specialists. There are no known practicable
  attacks against the algorithm using full rounds. The plugin
  implements CBC mode with a random IV for improved security.
  
  The following key sizes are recommended: 256, 192, and 128.
  Any other key sizes are not that well researched, and I do not
  recommend using them. There shouldn't be any problem though. If you
  are really paranoid, set the key size to 512 bits, otherwise use
  256, that's still plenty of security for the next decades.
  Internally, AES can only use multiples of 32 bits as key size. If
  you use other sizes, your key will be filled up with zeros to the
  next larger size usable.
  
  The smaller the key size, the faster and the weaker the encryption
  gets. You trade off speed with security.



------[ Usage / Installation ]------------------------------------------

  This plugin requires Back Orifice 2000, v1.1, in order to run.
  Make sure you get the latest version at www.bo2k.com.
  
  Add the plugin to both the client and the server, be sure to
  configure matching key strings and key sizes. You should now be able
  to select AES from any encryption drop-down menu, and you can
  specify AES in any encryption setting. Please be sure to use
  AES both in the client and the server, otherwise it wont work
  (surprise, surprise).
  
  If you can't figure out how to add plugins I suggest you go to your
  local software store and acquire a copy of PC Anywhere [tm], so you
  wont have to coap with the tremendous difficult task of adding a
  plugin :-P



------[ CBC Mode ]------------------------------------------------------

  Many commonly used ciphers (e.g. AES, CAST-256, IDEA) are block
  ciphers. This means that they take a fixed-size block of data
  (usually 128 bits), and transform it to another 128 bit block using
  a function selected by the key. The cipher basically defines a
  one-to-one mapping from 128-bit integers to another permutation of
  128-bit integers.
  
  If the same block is encrypted twice with the same key, the
  resulting ciphertext blocks are the same (this method of encryption
  is called Electronic Code Book mode, or ECB). This information could
  be useful for an attacker.
  
  In practical applications, it is desirable to make identical
  plaintext blocks encrypt to different ciphertext blocks. The Cypher
  Block Chaining (CBC) Mode does exactly that: a ciphertext block is
  obtained by first XORing the plaintext block with the previous
  ciphertext block, and encrypting the resulting value.
  
  This plugin implements only CBC, as BO2K encrypts data in chunks
  which have to be decoded completely. Even if using UDPIO, data is
  sent in small, independantly encrypted packets. Thus, ECB mode is
  not required, it merely made configuration more irritating.



------[ Algorithm ]-----------------------------------------------------

  The algorithm that became NIST's AES was originally named Rijndael.
  The two researchers who developed and submitted Rijndael for the AES
  are both cryptographers from Belgium: Dr. Joan Daemen of Proton 
  World International and Dr. Vincent Rijmen, a postdoctoral
  researcher in the Electrical Engineering Department (ESAT) of
  Katholieke Universiteit Leuven.
  
  When considered together, Rijndael's combination of security,
  performance, efficiency, ease of implementation and flexibility make
  it an appropriate selection for the AES. 
  
  Specifically, Rijndael appears to be consistently a very good
  performer in both hardware and software across a wide range of
  computing environments regardless of its use in feedback or
  non-feedback modes. Its key setup time is excellent, and its key
  agility is good. Rijndael's very low memory requirements make it
  very well suited for restricted-space environments, in which it also
  demonstrates excellent performance. Rijndael's operations are among
  the easiest to defend against power and timing attacks. 
  
  Additionally, it appears that some defense can be provided against
  such attacks without significantly impacting Rijndael's performance.
  Rijndael is designed with some flexibility in terms of block and
  key sizes, and the algorithm can accommodate alterations in the
  number of rounds, although these features would require further
  study and are not being considered at this time. Finally, Rijndael's
  internal round structure appears to have good potential to benefit
  from instruction-level parallelism.



------[ Legal Crap ]----------------------------------------------------

  The developers have allowed free use of the algorithm for any
  purpose.
  
  This implementation does not contain any code which was exported
  from the U.S. or Canada illegaly, thus this plugin constitutes no
  violation of the U.S. ITAR or other export regulations.
  
  In Switzerland, export of cryptographic software is legal and not
  subject to export restrictions, as long as it is available for free
  to anyone, and no additional services from the manufacturer are
  required to use the product. Thus this software is exportable
  without restrictions. I you believe this is not accurate, please
  notify me immediately. I do not intend to export this software
  illegally.



------[ License ]-------------------------------------------------------

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.
  
  This program is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
  USA
  
  If you do redistribute or modify it, please let me know.



------[ Thanx To ]------------------------------------------------------

  DilDog
    for answering (most) of my mails and for making BO2K possible
  the rest at cDc
    for being the rest at cDc
  Maw~ and Ryan and the other developers
    for the developers talk
  Chris, Brian, Sean, Christian and Irwan
    for the good bug reporting and helpful suggestions
  Ron
    for his backup copy of Serpent 1.0



------[ Contact ]-------------------------------------------------------

  Get the latest version of this plugin at the official distribution
  site http://www.roe.ch/bo2k
  
  Feel free to contact me, but please remember: I can and will not
  offer any support for BO2K itself. I can only answer questions
  directly related to any of my plugins. Send email to Daniel
  Roethlisberger <admin@roe.ch>. Alternatively, you can contact me
  through the ICQ network, my UIN is 4646931. Do not ask me to teach
  you how to hack hotmail or anything like that. Bullshit like that
  will be deleted immediately.
  
  I recommend to encrypt all email traffic with Pretty Good Privacy.
  Get my PGP-Key with ID 0x8DE543ED at ldap://certserver.pgp.com or
  from my website.
  
  Don't forget to visit the official BO2K site at http://www.bo2k.com



------[ Over and Out ]--------------------------------------------------

  <<better than any handle>>