NAME¶
ripemd128 - RIPEMD-128 Message-Digest Algorithm
SYNOPSIS¶
package require
Tcl 8.2
package require
ripemd128 ?1.0.3?
::ripemd::ripemd128 ?
-hex? [
-channel channel |
-file
filename |
string ]
::ripemd::hmac128 ?
-hex?
-key key [
-channel channel
|
-file filename |
string ]
::ripemd::RIPEMD128Init
::ripemd::RIPEMD128Update token data
::ripemd::RIPEMD128Final token
::ripemd::RIPEHMAC128Init key
::ripemd::RIPEHMAC128Update token data
::ripemd::RIPEHMAC128Final token
DESCRIPTION¶
This package is an implementation in Tcl of the RIPEMD-128 message-digest
algorithm (1). This algorithm takes an arbitrary quantity of data and
generates a 128-bit message digest from the input. The RIPEMD-128 algorithm is
based upon the MD4 algorithm (2, 4) but has been cryptographically
strengthened against weaknesses that have been found in MD4 (4). RIPEMD-128
has been designed to be a drop-in replacement for MD4 and MD5 (5). If security
is the major consideration, then RIPEMD-160 or SHA1 should be considered.
This package will use
Trf to accelerate the digest computation if
available. In the absence of an accelerator package the pure-Tcl
implementation will be used.
COMMANDS¶
- ::ripemd::ripemd128 ?-hex? [ -channel channel |
-file filename | string ]
- Calculate the RIPEMD-128 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
ripemd128 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.
- ::ripemd::hmac128 ?-hex? -key key [ -channel
channel | -file filename | string ]
- Calculate an Hashed Message Authentication digest (HMAC) using the
RIPEMD-128 digest algorithm. HMACs are described in RFC 2104 (6) and
provide a RIPEMD-128 digest that includes a key. All options other than
-key are as for the ::ripemd::ripemd128 command.
PROGRAMMING INTERFACE¶
For the programmer, hash functions can be viewed as a bucket into which one
pours data. When you have finished, you extract a value that is uniquely
derived from the data that was poured into the bucket. The programming
interface to the hash operates on a token (equivalent to the bucket). You call
RIPEMD128Init to obtain a token and then call
RIPEMD128Update as
many times as required to add data to the hash. To release any resources and
obtain the hash value, you then call
RIPEMD128Final. An equivalent set
of functions gives you a keyed digest (HMAC).
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 both the Trf and Memchan extensions are available then these
will be used. Finally the package will revert to a pure-Tcl implementation.
The programming interface remains the same, however.
- ::ripemd::RIPEMD128Init
- Begins a new RIPEMD-128 hash. Returns a token ID that must be used for the
remaining functions.
- ::ripemd::RIPEMD128Update token data
- Add data to the hash identified by token. Calling RIPEMD128Update
$token "abcd" is equivalent to calling RIPEMD128Update
$token "ab" followed by RIPEMD128Update $token
"cb". See EXAMPLES.
- ::ripemd::RIPEMD128Final 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 RIPEMD-128 digest value.
- ::ripemd::RIPEHMAC128Init key
- This is equivalent to the ::ripemd::RIPEMD128Init command except
that it requires the key that will be included in the HMAC.
- ::ripemd::RIPEHMAC128Update token data
- ::ripemd::RIPEHMAC128Final token
- These commands are identical to the RIPEMD128 equivalent commands.
EXAMPLES¶
% ripemd::ripemd128 -hex "Tcl does RIPEMD-128"
3cab177bae65205d81e7978f63556c63
% ripemd::hmac128 -hex -key Sekret "Tcl does RIPEMD-128"
b359dc5971a05beea0be7b106b30e389
% set tok [ripemd::RIPEMD128Init]
::ripemd::1
% ripemd::RIPEMD128Update $tok "Tcl "
% ripemd::RIPEMD128Update $tok "does "
% ripemd::RIPEMD128Update $tok "RIPEMD-128"
% ripemd::Hex [ripemd::RIPEMD128Final $tok]
3cab177bae65205d81e7978f63556c63
REFERENCES¶
- [1]
- H. Dobbertin, A. Bosselaers, B. Preneel, "RIPEMD-160, a strengthened
version of RIPEMD"
http://www.esat.kuleuven.ac.be/~cosicart/pdf/AB-9601/AB-9601.pdf
- [2]
- Rivest, R., "The MD4 Message Digest Algorithm", RFC 1320, MIT,
April 1992. ( http://www.rfc-editor.org/rfc/rfc1320.txt)
- [3]
- 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.
- [4]
- Dobbertin, H., "Cryptanalysis of MD4", Journal of Cryptology vol
11 (4), pp. 253-271 (1998)
- [5]
- 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)
- [6]
- 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
ripemd of the
Tcllib Trackers [
http://core.tcl.tk/tcllib/reportlist]. Please also
report any ideas for enhancements you may have for either package and/or
documentation.
SEE ALSO¶
md4, md5, ripemd160, sha1
KEYWORDS¶
RIPEMD, hashing, md4, message-digest, rfc 1320, rfc 1321, rfc 2104, security
CATEGORY¶
Hashes, checksums, and encryption
COPYRIGHT¶
Copyright (c) 2004, Pat Thoyts <patthoyts@users.sourceforge.net>