md4 -
MD4 Message-Digest Algorithm
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
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 implementation of the hashing function will be performed by compiled
code. Alternatively if cryptkit is available this will be
used. If no accelerator package can be found then the pure-tcl
implementation is used. The programming interface remains the same in
all cases.
-
::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 argument to
the md4 command, or as a filename or a pre-opened channel. 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.
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 equivalent 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.
% 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
-
Rivest, R., "The MD4 Message Digest Algorithm", RFC 1320, MIT,
April 1992. (http://www.rfc-editor.org/rfc/rfc1320.txt)
-
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.
-
Rivest, R., "The MD5 Message-Digest Algorithm", RFC 1321, MIT and
RSA Data Security, Inc, April 1992.
(http://www.rfc-editor.org/rfc/rfc1321.txt)
-
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)
This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such in the category
md4 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.
md5, sha1
md4, hashing, message-digest, security, rfc 1320, rfc 1321, rfc 2104