Provided by: tcllib_1.14-dfsg-1_all bug

NAME

       ripemd160 - RIPEMD-160 Message-Digest Algorithm

SYNOPSIS

       package require Tcl  8.2

       package require ripemd160  ?1.0.3?

       ::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.

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  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

       md4, md5, ripemd128, 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>