cryptTool Info
                     last update 4/24/2001
				 
This directory contains a program, cryptTool, intended to illustrate 
the use of the CDSA API to perform simple symmetric encryption 
and decryption. The program consists of one source file, cryptTool.c.

See the README in the parent directory (CDSA_Examples) for information
on building this program.

The cryptTool program is a command-line utility which does the 
following:

   create a symmetric key derived from a user-specified password;
   read a user-specified input file;
   either encrypt or decrypt that file using a the key generated
       above and a user-specified encryption algorithm;
   write the result out to a user-specified output file;
   
Several different symmetric encryption algorithms are supported,
illustrating the use of both stream and block ciphers. 

Running cryptTool with no command-line arguments gives usage 
instructions, like so:

	localhost> ./cryptTool 
	usage:
	./cryptTool op password keySize inFile outFile [a=algorithm]
	op:
		e  encrypt
		d  decrypt
	algorithm:
		4  RC4 (default if no algorithm specified)
		c  ASC/ComCryption
		d  DES
		a  AES

All arguments except for the last one are required. A description of the 
arguments follows.

   op          Indicates whether to encrypt (e) or decrypt (d)
   password    A user-specified ASCII string which is used to derive a
                  symmetric key.
   keySize     The key size in bytes. This is variable for stream ciphers
                  and fixed for block ciphers. 
   inFile      The name of the file to encrypt or decrypt.
   outFile     The name of the file to which the result of the encrypt or
                  decrypt is written. 
   algorithm   An optional algorithm. 
   
A shell script, runCrypt, is also provided which illustrates the actual 
usage of cryptTool to encrypt a file and decrypt the result. Run this
script with no arguments to show a typical sequence of operations. The
runCrypt script and the cryptTool executable must be in the same 
directory.