NAME

       yubikey-totp - Produce an OATH TOTP code using a YubiKey

SYNOPSIS

       yubikey-totp [-v] [-h] [--time | --step] [--digits] [--slot] [--debug]

DESCRIPTION

       OATH  codes  are  one  time  passwords  (OTP)  calculated in a standardized way. While the
       YubiKey is primarily used with Yubico OTP's, the YubiKey is also capable of producing OATH
       codes.

       OATH  generally  comes  in two flavors -- event based (called HOTP) and time based (called
       TOTP).  Since the YubiKey does not contain a battery, it cannot keep track of the  current
       time  itself  and  therefor  a  helper  application  such  as  yubikey-totp is required to
       effectively send the current time to the YubiKey, which can then perform the cryptographic
       calculation needed to produce the OATH code.

       Through  the  use  of  a helper application, such as yubikey-totp, the YubiKey can be used
       with sites offering OATH TOTP authentication, such as Google GMail.

OPTIONS

       -v     enable verbose mode.

       -h     show help

       --time specify the time value to use (in seconds since epoch)

       --step how frequent codes change in your system - typically 30 or 60 seconds

       --digits
              digits in OATH code - typically 6

       --slot YubiKey slot to use - default 2

       --debug
              enable debug output

EXAMPLE

       The YubiKey OATH  TOTP  operation  can  be  demonstrated  using  the  RFC  6238  test  key
       "12345678901234567890" (ASCII).

       First,  program  a YubiKey for HMAC-SHA1 Challenge-Response operation with the test vector
       HMAC key :

              $ ykpersonalize -2 -ochal-resp -ochal-hmac -ohmac-lt64 -o serial-api-visible \
                   -a 3132333435363738393031323334353637383930

       Now, send the NIST test challenge to  the  YubiKey  and  verify  the  result  matches  the
              expected :

              $ yubikey-totp --step 30 --digits 8 --time 1111111109
              07081804
              $

BUGS

       Report yubikey-totp bugs in the issue tracker ⟨https://github.com/Yubico/python-yubico/
       issues/⟩.

SEE ALSO

       YubiKeys can be obtained from Yubico ⟨http://www.yubico.com/⟩.