TOTP(1)

NAME
totp - time-based one time password generator

SYNOPSIS
totp <secret

DESCRIPTION
totp is a time-based one time password generator (TOTP). It reads a secret from standard input and prints the generated password, a numeric code, to standard output. The secret is usually provided by the authenticator (for e.g. a website) and is either a base32-encoded string or a ‘otpauth://’ URI. Blanks in the secret string are ignored, but only one line is read.

totp uses a period of 30 seconds, HMAC-SHA1 and generates six digits long codes, unless the URI specifies otherwise.

EXIT STATUS

EXAMPLES
totp is meant to be used with plass(1) or similar application: the secret is stored safely in the password store and then given to totp using a pipe:

    $ plass cat 2fa/codeberg/op | totp
    722524

SEE ALSO
plass(1)

STANDARDS
totp follows the algorithm outlined in RFC 6238 “TOTP: Time-Based One-Time Password Algorithm” and uses the base32 encoding as defined in RFC 3548 “The Base16, Base32, and Base64 Data Encodings”. ‘otpauth://’ URIs are parsed as per the “Key URI Format” proposed by Google Authenticator.

AUTHORS
-nosplit The totp utility was written by Omar Polo <op@omarpolo.com>.