Automated OTP responder based on fish shell - maybe not a great idea but convenient :)

otpresponder

#!/usr/bin/fish
while true
    set resp (inotifywait /run/systemd/ask-password -e moved_to)
    set file = (string split ' ' $resp)
    set pfile "/run/systemd/ask-password/$file[4]"
    if grep "$CHALLENGE_KEY" $pfile >/dev/null
        set socket (grep -i socket $pfile | sed s/socket=//i)
        set ticket (oathtool -b --totp "$OTP_KEY")
        echo socket "$socket"
        echo "$ticket" | /lib/systemd/systemd-reply-password 1 "$socket"
        echo code sent
    end
end

otpresponder.service

[Unit]
Description=OTP responder

[Service]
Type=simple
Environment=CHALLENGE_KEY=mychallengekey
Environment=OTP_KEY=myotpkey
ExecStart=/usr/local/bin/otpresponder

[Install]
WantedBy=multi-user.target