NAME

       otp - One-Time Passwords

SYNOPSIS

       package require Tcl  8.2

       package require otp  ?1.0.0?

       ::otp::otp-md4 ?-hex? ?-words? -seed seed -count count data

       ::otp::otp-md5 ?-hex? ?-words? -seed seed -count count data

       ::otp::otp-sha1 ?-hex? ?-words? -seed seed -count count data

       ::otp::otp-rmd160 ?-hex? ?-words? -seed seed -count count data

_________________________________________________________________________________________________

DESCRIPTION

       This  package  is an implementation in Tcl of the One-Time Password system as described in
       RFC 2289 (1). This system uses message-digest algorithms to sequentially hash a passphrase
       to  create single-use passwords. The resulting data is then provided to the user as either
       hexadecimal digits or encoded using a dictionary of 2048 words. This  system  is  used  by
       OpenBSD for secure login and can be used as a SASL mechanism for authenticating users.

       In  this  implementation  we  provide support for four algorithms that are included in the
       tcllib distribution: MD5 (2), MD4 (3), RIPE-MD160 (4) and SHA-1 (5).

COMMANDS

       ::otp::otp-md4 ?-hex? ?-words? -seed seed -count count data

       ::otp::otp-md5 ?-hex? ?-words? -seed seed -count count data

       ::otp::otp-sha1 ?-hex? ?-words? -seed seed -count count data

       ::otp::otp-rmd160 ?-hex? ?-words? -seed seed -count count data

EXAMPLES

              % otp::otp-md5 -count 99 -seed host67821 "My Secret Pass Phrase"
              (binary gibberish)
              % otp::otp-md5 -words -count 99 -seed host67821 "My Secret Pass Phrase"
              SOON ARAB BURG LIMB FILE WAD
              % otp::otp-md5 -hex -count 99 -seed host67821 "My Secret Pass Phrase"
              e249b58257c80087

REFERENCES

       [1]    Haller, N.  et  al.,  "A  One-Time  Password  System",  RFC  2289,  February  1998.
              http://www.rfc-editor.org/rfc/rfc2289.txt

       [2]    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)

       [3]    Rivest, R., "The  MD4  Message  Digest  Algorithm",  RFC  1320,  MIT,  April  1992.
              (http://www.rfc-editor.org/rfc/rfc1320.txt)

       [4]    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

       [5]    "Secure Hash Standard",  National  Institute  of  Standards  and  Technology,  U.S.
              Department             Of             Commerce,             April             1995.
              (http://www.itl.nist.gov/fipspubs/fip180-1.htm)

BUGS, IDEAS, FEEDBACK

       This document, and the package it describes,  will  undoubtedly  contain  bugs  and  other
       problems.    Please   report   such   in   the   category   otp  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

       SASL, md4, md5, ripemd160, sha1

KEYWORDS

       hashing, message-digest, password, rfc 2289, security

CATEGORY

       Hashes, checksums, and encryption

COPYRIGHT

       Copyright (c) 2006, Pat Thoyts <patthoyts@users.sourceforge.net>