Ubuntu Manpage: ripemd160 - RIPEMD-160 Message-Digest Algorithm

NAME

       ripemd160 - RIPEMD-160 Message-Digest Algorithm

SYNOPSIS

       package require Tcl 8.5 9

       package require ripemd160 ?1.0.7?

       ::ripemd::ripemd160 ?-hex? [ -channel channel | -file filename | string ]

       ::ripemd::hmac160 ?-hex? -key key [ -channel channel | -file filename | string ]

       ::ripemd::RIPEMD160Init

       ::ripemd::RIPEMD160Update token data

       ::ripemd::RIPEMD160Final token

       ::ripemd::RIPEHMAC160Init key

       ::ripemd::RIPEHMAC160Update token data

       ::ripemd::RIPEHMAC160Final token

________________________________________________________________________________________________________________

DESCRIPTION

       This  package  is an implementation in Tcl of the RIPEMD-160 message-digest algorithm (1). This algorithm
       takes an arbitrary quantity of data and generates a 160-bit message digest from the input. The RIPEMD-160
       algorithm is based upon the MD4 algorithm (2, 4) but  has  been  cryptographically  strengthened  against
       weaknesses that have been found in MD4 (4).

       This  package  will  use  cryptkit  or  Trf  to  accelerate  the  digest computation if either package is
       available. In the absence of an accelerator package the pure-Tcl implementation will be used.

       BEWARE The commands in this package expect binary data as their input.  When a  -file  is  provided  then
       this  is  ensured  by  the  commands  themselves,  as they open the referenced file in binary mode.  When
       literal data, or a -channel are provided instead, then the command's caller is responsible  for  ensuring
       this fact.  The necessary conversion command is encoding convertto utf-8 $string.

       ATTENTION, there is a Tcl 9 COMPATIBILITY ISSUE here.

       Tcl 8.x silently mishandles non-binary input by cutting it internally to size. I.e. by only using the low
       byte of a higher unicode point.  No error is thrown, the result is simply wrong.

       Tcl 9 throws an error instead, i.e.

              expected byte sequence but character <location> was ...

COMMANDS

       ::ripemd::ripemd160 ?-hex? [ -channel channel | -file filename | string ]
              Calculate  the  RIPEMD-160 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 ripemd160 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::hmac160 ?-hex? -key key [ -channel channel | -file filename | string ]
              Calculate an Hashed Message Authentication digest (HMAC) using the  RIPEMD-160  digest  algorithm.
              HMACs  are  described  in  RFC  2104  (5) and provide a RIPEMD-160 digest that includes a key. All
              options other than -key are as for the ::ripemd::ripemd160 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 RIPEMD160Init
to obtain a token and then call RIPEMD160Update as many times as required to add data to the hash. To
release any resources and obtain the hash value, you then call RIPEMD160Final. An equivalent set of
functions gives you a keyed digest (HMAC).

::ripemd::RIPEMD160Init
Begins a new RIPEMD-160 hash. Returns a token ID that must be used for the remaining functions.

::ripemd::RIPEMD160Update token data
Add data to the hash identified by token. Calling RIPEMD160Update $token "abcd" is equivalent to
calling RIPEMD160Update $token "ab" followed by RIPEMD160Update $token "cb". See EXAMPLES.

::ripemd::RIPEMD160Final 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 160 bit
RIPEMD-160 digest value.

::ripemd::RIPEHMAC160Init key
This is equivalent to the ::ripemd::RIPEMD160Init command except that it requires the key that
will be included in the HMAC.

::ripemd::RIPEHMAC160Update token data

::ripemd::RIPEHMAC160Final token
These commands are identical to the RIPEMD160 equivalent commands.

EXAMPLES

              % ripemd::ripemd160 -hex "Tcl does RIPEMD-160"
              0829dea75a1a7074c702896723fe37763481a0a7

              % ripemd::hmac160 -hex -key Sekret "Tcl does RIPEMD-160"
              bf0c927231733686731dddb470b64a9c23f7f53b

              % set tok [ripemd::RIPEMD160Init]
              ::ripemd::1
              % ripemd::RIPEMD160Update $tok "Tcl "
              % ripemd::RIPEMD160Update $tok "does "
              % ripemd::RIPEMD160Update $tok "RIPEMD-160"
              % ripemd::Hex [ripemd::RIPEMD160Final $tok]
              0829dea75a1a7074c702896723fe37763481a0a7

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]    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.

       When proposing code changes, please provide unified diffs, i.e the output of diff -u.

       Note  further  that  attachments  are strongly preferred over inlined patches. Attachments can be made by
       going to the Edit form of the ticket immediately after its creation, and then using the left-most  button
       in the secondary navigation bar.

KEYWORDS

       RIPEMD, hashing, md4, message-digest, rfc 1320, rfc 1321, rfc 2104, security

COPYRIGHT

       Copyright (c) 2004, Pat Thoyts <patthoyts@users.sourceforge.net>

tcllib                                                1.0.7                                      ripemd160(3tcl)