.Dd $Mdocdate: October 3 2023 $
.Dt TOTP 1
.Os
.Sh NAME
.Nm totp
.Nd generate TOTP codes
.Sh SYNOPSIS
.Nm
.Op Fl d Ar digits
.Op Fl p Ar period
.Op Fl u
.Op Ar secret ...
.Sh DESCRIPTION
.Nm
is a utility to generate TOTP codes on the command\-line.
You can provide TOTP secret codes either through the standard input or as
command\-line.
If you would like to use OTP URIs instead, those are also supported through the
.Fl u
option, which enables URI parsing of inputs.
.Pp
When working with OTP URIs, metadata regarding the digit length or the duration
period of TOTP codes is typically contained within the URI, and
.Nm
parses and interprets that information for you.
This is not the case when using raw TOTP secret codes.
When using TOTP secret codes, it is assumed that TOTP codes are 6 digits long
with a duration of 30 seconds.
If you need different defaults you can make use of the
.Fl d
and
.Fl p
flags.
.Pp
The options are as follows:
.Bl -tag width Ds
.It Fl d , Fl Fl digits Ns = Ns Ar length
Set the digit length of TOTP codes to
.Ar length .
If this flag is not specified, the digit length defaults to 6 digits.
.It Fl p , Fl Fl period Ns = Ns Ar seconds
Set the duration period of TOTP codes to
.Ar seconds .
If this flag is not specified, the duration period defaults to 30 seconds.
.It Fl u , Fl Fl uri
Interpret input as OTP URIs instead of raw TOTP secret keys.
.El
.Sh EXIT STATUS
.Ex -std
.Sh EXAMPLES
Get TOTP codes for two different secret keys using the standard input:
.Pp
.Dl $ printf '7KFSJ562KJDK23KD\en7YNEG7J3XBIVYR54' | totp
.Pp
The same as the above but using command\-line arguments:
.Pp
.Dl $ totp 7KFSJ562KJDK23KD 7YNEG7J3XBIVYR54
.Pp
Get a TOTP code for an OTP URI:
.Pp
.Dl $ totp -u 'otpauth://totp/GitHub:Mango0x45?secret=7YNEG7J3XBIVYR54'
.Pp
The same as above, but extract the URI from a QR\-code using
.Xr zbarimg 1 :
.Pp
.Dl $ zbarimg -q qr.png | sed 's/QR-Code://' | totp -u
.Pp
Generate an 8 digit TOTP code that is valid for 60 seconds:
.Pp
.Dl $ totp -d8 -p60 7KFSJ562KJDK23KD
.Sh SEE ALSO
.Xr sed 1 ,
.Xr zbarimg 1 ,
.Xr HMAC 3ssl ,
.Xr SHA1 3ssl
.Pp
.Lk https://thomasvoss.com/prj/totp "Extended Description and -Documentation"
.Sh AUTHORS
.An Thomas Voss Aq Mt mail@thomasvoss.com