md4(n) MD4 Message-Digest Algorithm md4(n) ______________________________________________________________________________
NAME
md4 - MD4 Message-Digest Algorithm
SYNOPSIS
package require Tcl 8.2
package require md4 ?1.0?
::md4::md4 ?-hex? [ -channel channel | -file filename | string ]
::md4::hmac ?-hex? -key key [ -channel channel | -file filename |
string ]
::md4::MD4Init
::md4::MD4Update token data
::md4::MD4Final token
::md4::HMACInit key
::md4::HMACUpdate token data
::md4::HMACFinal token
_________________________________________________________________
DESCRIPTION
This package is an implementation in Tcl of the MD4 message-digest
algorithm as described in RFC 1320 (1) and (2). This algorithm takes an
arbitrary quantity of data and generates a 128-bit message digest from
the input. The MD4 algorithm is faster but potentially weaker than the
related MD5 algorithm (3).
If you have critcl and have built the tcllibc package then the imple-
mentation of the hashing function will be performed by compiled code.
Alternatively if cryptkit is available this will be used. If no accel-
erator package can be found then the pure-tcl implementation is used.
The programming interface remains the same in all cases.
COMMANDS
::md4::md4 ?-hex? [ -channel channel | -file filename | string ]
Calculate the MD4 digest of the data given in string. This is
returned as a binary string by default. Giving the -hex option
will return a hexadecimal encoded version of the digest.
The data to be hashed can be specified either as a string argu-
ment to the md4 command, or as a filename or a pre-opened chan-
nel. If the -filename argument is given then the file is opened,
the data read and hashed and the file is closed. If the -channel
argument is given then data is read from the channel until the
end of file. The channel is not closed.
Only one of -file, -channel or string should be given.
::md4::hmac ?-hex? -key key [ -channel channel | -file filename |
string ]
Calculate an Hashed Message Authentication digest (HMAC) using
the MD4 digest algorithm. HMACs are described in RFC 2104 (4)
and provide an MD4 digest that includes a key. All options other
than -key are as for the ::md4::md4 command.
PROGRAMMING INTERFACE
For the programmer, the MD4 hash can be viewed as a bucket into which
one pours data. When you have finished, you extract a value that is
derived from the data that was poured into the bucket. The programming
interface to the MD4 hash operates on a token (equivalent to the
bucket). You call MD4Init to obtain a token and then call MD4Update as
many times as required to add data to the hash. To release any
resources and obtain the hash value, you then call MD4Final. An equiva-
lent set of functions gives you a keyed digest (HMAC).
::md4::MD4Init
Begins a new MD4 hash. Returns a token ID that must be used for
the remaining functions.
::md4::MD4Update token data
Add data to the hash identified by token. Calling MD4Update
$token "abcd" is equivalent to calling MD4Update $token "ab"
followed by MD4Update $token "cb". See EXAMPLES.
::md4::MD4Final token
Returns the hash value and releases any resources held by this
token. Once this command completes the token will be invalid.
The result is a binary string of 16 bytes representing the 128
bit MD4 digest value.
::md4::HMACInit key
This is equivalent to the ::md4::MD4Init command except that it
requires the key that will be included in the HMAC.
::md4::HMACUpdate token data
::md4::HMACFinal token
These commands are identical to the MD4 equivalent commands.
EXAMPLES
% md4::md4 -hex "Tcl does MD4"
858da9b31f57648a032230447bd15f25
% md4::hmac -hex -key Sekret "Tcl does MD4"
c324088e5752872689caedf2a0464758
% set tok [md4::MD4Init]
::md4::1
% md4::MD4Update $tok "Tcl "
% md4::MD4Update $tok "does "
% md4::MD4Update $tok "MD4"
% md4::Hex [md4::MD4Final $tok]
858da9b31f57648a032230447bd15f25
REFERENCES
[1] Rivest, R., "The MD4 Message Digest Algorithm", RFC 1320, MIT,
April 1992. (http://www.rfc-editor.org/rfc/rfc1320.txt)
[2] Rivest, R., "The MD4 message digest algorithm", in A.J. Menezes
and S.A. Vanstone, editors, Advances in Cryptology - CRYPTO '90
Proceedings, pages 303-311, Springer-Verlag, 1991.
[3] Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, MIT
and RSA Data Security, Inc, April 1992. (http://www.rfc-edi-
tor.org/rfc/rfc1321.txt)
[4] Krawczyk, H., Bellare, M. and Canetti, R. "HMAC: Keyed-Hashing
for Message Authentication", RFC 2104, February 1997.
(http://www.rfc-editor.org/rfc/rfc2104.txt)
BUGS, IDEAS, FEEDBACK
This document, and the package it describes, will undoubtedly contain
bugs and other problems. Please report such in the category md4 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.
SEE ALSO
md5(n), sha1(n)
KEYWORDS
hashing, md4, message-digest, rfc 1320, rfc 1321, rfc 2104, security
CATEGORY
Hashes, checksums, and encryption
COPYRIGHT
Copyright (c) 2003, Pat Thoyts <patthoyts@users.sourceforge.net>
md4 1.0.5 md4(n)
Mac OS X 10.8 - Generated Sun Sep 9 15:12:26 CDT 2012