SKEY(5)                   OpenBSD Programmer's Manual                  SKEY(5)

NAME
     skey - one-time password user database

DESCRIPTION
     The /etc/skey directory contains user records for the S/Key one-time
     password authentication system.

     Records take the form of files within /etc/skey where each file is named
     for the user whose record it contains.  For example, /etc/skey/root would
     hold root's S/Key record.

     The mode for /etc/skey should be 01730 and it should be owned by root and
     group auth.  Individual records within /etc/skey should be owned by the
     user they describe and be mode 0600.  To access S/Key records, a process
     must run as group auth.

     Each record consists of five lines:

     1.   The name of the user the record describes.  This should be the same
          as the name of the file.

     2.   The hash type used for this entry; one of md4, md5, sha1, or rmd160.
          The default is md5.

     3.   The sequence number.  This is a decimal number between one and one
          thousand.  Each time the user authenticates via S/Key this number is
          decremented by one.

     4.   A seed used along with the sequence number and the six S/Key words
          to compute the value.

     5.   The value expected from the crunching of the user's seed, sequence
          number and the six S/Key words.  When the result matches this value,
          authentication is considered to have been successful.

FILES
     /etc/skey

EXAMPLES
     Here is a sample /etc/skey file for root:

           root
           md5
           99
           obsd36521
           1f4359a3764b675d

SEE ALSO
     skey(1), skeyinit(1), skey(3)

OpenBSD 4.7                      May 31, 2007                                1
