rc4(n) RC4 Stream Cipher rc4(n) 







rc4 - Implementation of the RC4 stream cipher








package require Tcl 8.2


package require rc4 ?1.1.0?


::rc4::rc4 ?-hex? -key keyvalue ?-command
    lst? ?-out channel? [ -in channel | -infile
    filename | string ]


::rc4::RC4Init keydata


::rc4::RC4 Key data


::rc4::RC4Final Key












This package is an implementation in Tcl of the RC4 stream cipher
    developed by Ron Rivest of RSA Data Security Inc. The cipher was a trade
    secret of RSA but was reverse-engineered and published to the internet in
    1994. It is used in a number of network protocols for securing
    communications. To evade trademark restrictions this cipher is sometimes
    known as ARCFOUR.









  
::rc4::rc4 ?-hex? -key keyvalue ?-command lst?
    ?-out channel? [ -in channel | -infile filename |
    string ]

  
Perform the RC4 algorithm on either the data provided by the argument or
      on the data read from the -in channel. If an -out channel is
      given then the result will be written to this channel. Giving the
      -hex option will return a hexadecimal encoded version of the result
      if not using an -out channel.
    
The data to be processes can be specified either as a string
        argument to the rc4 command, or as a filename or a pre-opened channel.
        If the -infile argument is given then the file is opened, the
        data read and processed and the file is closed. If the -in
        argument is given then data is read from the channel until the end of
        file. The channel is not closed. If the -out argument is given
        then the processing result is written to this channel.

    
If -command is provided then the rc4 command does not
        return anything. Instead the command provided is called with the rc4
        result data appended as the final parameter. This is most useful when
        reading from Tcl channels as a fileevent is setup on the channel and the
        data processed in chunks

    
Only one of -infile, -in or string should
        be given.

  











  
::rc4::RC4Init keydata

  
Initialize a new RC4 key. The keydata is any amount of binary data
      and is used to initialize the cipher internal state.

  
::rc4::RC4 Key data

  
Encrypt or decrypt the input data using the key obtained by calling
      RC4Init.

  
::rc4::RC4Final Key

  
This should be called to clean up resources associated with Key.
      Once this function has been called the key is destroyed.










% set keydata [binary format H* 0123456789abcdef]
% rc4::rc4 -hex -key $keydata HelloWorld
3cf1ae8b7f1c670b612f
% rc4::rc4 -hex -key $keydata [binary format H* 3cf1ae8b7f1c670b612f]
HelloWorld





 set Key [rc4::RC4Init "key data"]


 append ciphertext [rc4::RC4 $Key $plaintext]


 append ciphertext [rc4::RC4 $Key $additional_plaintext]


 rc4::RC4Final $Key





 proc ::Finish {myState data} {


     DoStuffWith $myState $data


 }


 rc4::rc4 -in $socket -command [list ::Finish $ApplicationState]









Pat Thoyts








This document, and the package it describes, will undoubtedly
    contain bugs and other problems. Please report such in the category
    rc4 of the Tcllib SF Trackers
    [http://sourceforge.net/tracker/?group_id=12883]. Please also report any
    ideas for enhancements you may have for either package and/or
  documentation.








aes(n), blowfish(n), des(n)








arcfour,, data integrity, encryption, rc4, security, stream
  cipher








Hashes, checksums, and encryption








Copyright (c) 2003, Pat Thoyts <patthoyts@users.sourceforge.net>








  

    1.1.0
    rc4