1rc4(n) RC4 Stream Cipher rc4(n)
2______________________________________________________________________________
6
8 rc4 - Impementation of the RC4 stream cipher
9
11 package require Tcl 8.2
12 package require rc4 ?1.1.0?
14 ::rc4::rc4 ?-hex? -key keyvalue ?-command lst? ?-out channel? [ -in
16 channel | -infile filename | string ]
17 ::rc4::RC4Init keydata
19 ::rc4::RC4 Key data
21 ::rc4::RC4Final Key
23_________________________________________________________________
25
27 This package is an implementation in Tcl of the RC4 stream cipher
28 developed by Ron Rivest of RSA Data Security Inc. The cipher was a
29 trade secret of RSA but was reverse-engineered and published to the
30 internet in 1994. It is used in a number of network protocols for
31 securing communications. To evade trademark restrictions this cipher is
32 sometimes known as ARCFOUR.
33
35 ::rc4::rc4 ?-hex? -key keyvalue ?-command lst? ?-out channel? [ -in
36 channel | -infile filename | string ]
37 Perform the RC4 algorithm on either the data provided by the
38 argument or on the data read from the -in channel. If an -out
39 channel is given then the result will be written to this chan‐
40 nel. Giving the -hex option will return a hexadecimal encoded
41 version of the result if not using an -out channel.
42 The data to be processes can be specified either as a string
44 argument to the rc4 command, or as a filename or a pre-opened
45 channel. If the -infile argument is given then the file is
46 opened, the data read and processed and the file is closed. If
47 the -in argument is given then data is read from the channel
48 until the end of file. The channel is not closed. If the -out
49 argument is given then the processing result is written to this
50 channel.
51 If -command is provided then the rc4 command does not return
53 anything. Instead the command provided is called with the rc4
54 result data appended as the final parameter. This is most useful
55 when reading from Tcl channels as a fileevent is setup on the
56 channel and the data processed in chunks
57 Only one of -infile, -in or string should be given.
59
61 ::rc4::RC4Init keydata
62 Initialize a new RC4 key. The keydata is any amount of binary
63 data and is used to initialize the cipher internal state.
64 ::rc4::RC4 Key data
66 Encrypt or decrypt the input data using the key obtained by
67 calling RC4Init.
68 ::rc4::RC4Final Key
70 This should be called to clean up resources associated with Key.
71 Once this function has been called the key is destroyed.
72
74 % set keydata [binary format H* 0123456789abcdef]
75 % rc4::rc4 -hex -key $keydata HelloWorld
76 3cf1ae8b7f1c670b612f
77 % rc4::rc4 -hex -key $keydata [binary format H* 3cf1ae8b7f1c670b612f]
78 HelloWorld
79 set Key [rc4::RC4Init "key data"]
82 append ciphertext [rc4::RC4 $Key $plaintext]
83 append ciphertext [rc4::RC4 $Key $additional_plaintext]
84 rc4::RC4Final $Key
85 proc ::Finish {myState data} {
88 DoStuffWith $myState $data
89 }
90 rc4::rc4 -in $socket -command [list ::Finish $ApplicationState]
91
94 Pat Thoyts
95
97 This document, and the package it describes, will undoubtedly contain
98 bugs and other problems. Please report such in the category rc4 of the
99 Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883].
100 Please also report any ideas for enhancements you may have for either
101 package and/or documentation.
102
104 aes(n), blowfish(n), des(n)
105
107 arcfour,, data integrity, encryption, rc4, security, stream cipher
108
110 Copyright (c) 2003, Pat Thoyts <patthoyts@users.sourceforge.net>
111rc4 1.1.0 rc4(n)