NAME    [Toc]    [Back]

     skey, otp-md4, otp-md5, otp-sha1, otp-rmd160 - respond to an
OTP challenge

SYNOPSIS    [Toc]    [Back]

     skey  [-x]  [-md4  |  -md5 | -sha1 | -rmd160] [-n count] [-p
passphrase] <sequence#>[/]
 key

DESCRIPTION    [Toc]    [Back]

     S/Key is a procedure for using one-time passwords to authenticate access
     to  computer systems.  It uses 64 bits of information transformed by the
     MD4, MD5, SHA1, or RIPEMD-160 algorithms.  The user supplies
the 64 bits
     in  the  form of 6 English words that are generated by a secure computer.
     This implementation of S/Key is RFC 2289 compliant.

     Before using skey the system needs to be  initialized  using
skeyinit(1);
     this  will  establish a secret passphrase.  After that, onetime passwords
     can be generated using skey, which will prompt for  the  secret passphrase.
     After a one-time password has been used to log in, it can no
longer be
     used.

     When skey is invoked as otp-method, skey will use method  as
the hash
     function where method is currently one of md4, md5, sha1, or
rmd160.

     If you misspell your secret passphrase while  running  skey,
you will get a
     list  of one-time passwords that will not work, and no indication of the
     problem.

     Password sequence numbers count backwards.   You  can  enter
the passwords
     using  small  letters, even though skey prints them capitalized.

     The options are as follows:

     -n count
             Prints out count one-time passwords.  The default is
to print
             one.

     -p passphrase
             Uses  passphrase  as  the secret passphrase.  Use of
this option is
             discouraged as your secret passphrase could be visible in a process
 listing.

     -x      Causes output to be in hexadecimal instead of ASCII.

     -md4    Selects MD4 as the hash algorithm.

     -md5    Selects MD5 as the hash algorithm.

     -sha1   Selects SHA-1 (NIST Secure Hash  Algorithm  Revision
1) as the hash
             algorithm.

     -rmd160
             Selects RMD-160 (160 bit Ripe Message Digest) as the
hash algorithm.

EXAMPLES    [Toc]    [Back]

           $ skey 99 th91334
           Reminder - Do not use this program while logged in via
telnet.
           Enter  secret  passphrase:  <your secret passphrase is
entered here>
           OMEN US HORN OMIT BACK AHOY
           $

SEE ALSO    [Toc]    [Back]

     login(1),    skeyaudit(1),     skeyinfo(1),     skeyinit(1),
skeyprune(8)

     RFC 2289

TRADEMARKS AND PATENTS    [Toc]    [Back]

     S/Key is a Trademark of Bellcore.

AUTHORS    [Toc]    [Back]

     Phil Karn, Neil M. Haller, John S. Walden, Scott Chasin

OpenBSD      3.6                         October     28,     1993