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
http://sourceforge.net/tracker/?group_id=12883.
Please also report any ideas for enhancements you may have for either
package and/or documentation.
des(n), aes(n), blowfish(n)
rc4, arcfour,, stream cipher, security, encryption, data integrity