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/⟩.