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.

       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.

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>