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>

tcllib                                                1.0.0                                            otp(3tcl)