NAME

Auth::GoogleAuthenticator - Authenticate through Google Authenticator

WORKFLOW

• Install Google Authenticator

• Visit the "Install Two Factor Authentication" page

• Display the secret key there

  ->registration_qr_code
  ->registration_key

  Display the "Panic" OTPs there so that the user can print them out on paper and store them in a secure location:

  my @recovery_passwords = generate_recovery_strings( 3 );
  for my $pass ( @recovery_passwords ) {
    print $pass, "\n";
  };

• Photograph the QR code

  or

  Manually enter the key into the Authenticator

• On the Login page enter the password and the OTP code from the Authenticator or on the Recovery page, enter one of the panic keys.

PASSWORD STORAGE

The password should be stored as a hash.

The shared authenticator secret needs to be stored as plaintext.

RECOVERY

As phones tend to get lost, the recovery passphrases become important. They also are password equivalent. So, my recommendation is to store the recovery passphrases only as hashes, just like you store passwords.

COMPATIBILITY

At least on iDevices, using < or > made registering the generated accounts through QRcodes fail. The QRcodes work with Android devices.

SEE ALSO

TOTP: Time-Based One-Time Password Algorithm

http://tools.ietf.org/html/rfc6238