my $s = readFile $secretKeyFile;
        chomp $s;
        my ($keyName, $secretKey) = split ":", $s;
        die "invalid secret key file\n" unless defined $keyName && defined $secretKey;

        my $secretKey = readFile $secretKeyFile;

        my $sig = encode_base64(signString(decode_base64($secretKey), $fingerprint), "");
        $info .= "Sig: $keyName:$sig\n";

        my $sig = signString($secretKey, $fingerprint);
        $info .= "Sig: $sig\n";