AESCrypt: Rijndael encryption for shell scripts.
                                      
   This is a program for encrypting/decrypting streams of data using
   Rijndael and Cipher Block Feedback mode (CFB-128).

Usage:

   aescrypt -k {keyfile} [-s 128|192|256]
   aesget -k {keyfile} [-s 128|192|256] 

   Encrypt/decrypt stdin using the Advanced Encryption Standard
   winner "Rijndael" encryption algorithm in Cipher Block Feedback
   (stream) mode. Uses /dev/urandom to create a salt. Prepends the
   output stream with salt when encrypting, strips it off when decrypting. 

   Keyfile format: 
   ...
   kk=hexdits
   ...

   where hexdits is: 

   32 chars for 128 bit
   48 chars for 196 bits. 
   64 chars for 256 bits 
   
   Note that there may be other text in the file. But the key must be at
   start of a line, and must start with 'kk=', and must be hex.
   
   If the key file is "-", it instead reads the hex-coded key bytes off
   stdin and treats them as a null-terminated hex key. Care must be taken
   when reading the key from stdin, as you must supply exactly 33 bytes
   for 128 bit keys, 49 bytes for 192 bit keys, and 65 bytes for 256 bit
   keys. The stdin functionality is useful in those cases where having the
   unencrypted key in a file is undesirable, but it is less forgiving in
   terms of key format. 
 
Limitations:

   1. The keyfile is *NOT* encrypted. 
   2. Now supports 192 and 256 bit keys! 128 bits is the default, so it is
      backward compatible with aescrypt versions not endowed with the -s option. 
   3. Need a key generator! ( This should be a simple shell script -- use dd to
      grab some data, then md5sum to create a hex mix of that data, then 'awk'
      to grab the hex part of the output of md5sum ). 
   4. Relies upon having /dev/urandom. See the Ocotillo PRNG if you don't have
      a /dev/urandom. 
   5. This program was deliberately kept extremely simple. It is not intended to
      be a full encryption solution, it is intended to be used within scripts as
      part of a complete solution. Keychain management, public key signatures, etc.
      are all expected to be done external to this program.
       
Legal Notices

   This software is a cryptographic component. It is not for export or
   redistribution to any of what are called the "T-10 Terrorist States"
   as detirmined by the U.S. Department of State. Please comply with this
   restriction so that this site is not forced to shut down.
   
Installation:

   ./configure -prefix=/opt/brupro
   make
   make install
   
Authors:

   AESCrypt was written by Eric Lee Green, and was modified to use
   Rijndael rather than Twofish by Randy Kielber. AESCrypt is copyrighted
   by Enhanced Software Technologies Inc., but is released under a
   BSD-style Open Source license. See file LICENSE for info.
   
   Attribution information: This software includes Rijndael encryption
   routines by Antoon Bosselaers and Vincent Rijmen. They have stated
   that their routines are free for public use.
   
    Eric Lee Green


The aescrypt homepage is located here:

	http://aescrypt.sourceforge.net/