totp is a command-line utility to generate TOTP keys from the command-line.
This is very useful for integrating 2-factor authentication support into your
existing password-management setup. totp supports both TOTP secret keys and
OTP URIs as input. This means you can also integrate totp together with
zbarimg to generate TOTP codes from scannable QR codes.
totp depends on libssl, libcrypto, and liburiparser. You probably already
have the first two. If liburiparser isn’t in your systems repositories, you can
obtain it from here
Installation is made easy with the provided Makefile:
$ make
$ make install
The totp utility reads TOTP secret keys from the standard input and prints the
corresponding codes to the standard output. You can use multiple keys:
$ printf '7KFSJ562KJDK23KD\n7YNEG7J3XBIVYR54' | totp
546316
942303
You can also provide the keys as arguments:
$ totp 7KFSJ562KJDK23KD 7YNEG7J3XBIVYR54
546316
942303
By default it is assumed that the TOTP codes have a length of 6 and are valid
for 30 seconds. You can change both of these parameters using the -d and -p
respectively, if required:
$ totp -d8 -p60 7KFSJ562KJDK23KD 7YNEG7J3XBIVYR54
71696020
18335070
It might be useful however to instead use an OTP URI. These are the URIs
embedded within 2-factor authentication QR codes, and often contain the metadata
specifying the length and period of the generated codes. To use URIs, use the
-u flag:
$ totp -u 'otpauth://totp/GitHub:Mango0x45?secret=7YNEG7J3XBIVYR54'
942303
This also works with the standard input:
$ echo 'otpauth://totp/GitHub:Mango0x45?secret=7YNEG7J3XBIVYR54' | totp -u
942303
zbarimg is a helpful CLI utility that we can use to get an OTP URI from a QR
code. Here is an example of how we can use it to generate a TOTP code from a
2-factor authentication QR code:
$ zbarimg -q qr-code.png | sed 's/QR-Code://' | totp
546316