public String getSecret() {

        // Do not reveal TOTP mode unless enrollment is in progress
        if (key == null)
            return null;

        return BASE32.encode(key.getSecret());

    }
Returns the base32-encoded secret key that is being used to generate TOTP
codes for the authenticating user. If the user's key is not being exposed
to facilitate enrollment, this value will not be exposed either.

@return
    The base32-encoded secret key that is being used to generate TOTP
    codes for the authenticating user, or null if the user's key is not
    being exposed to facilitate enrollment.
extensions/guacamole-auth-totp/src/main/java/org/apache/guacamole/auth/totp/form/AuthenticationCodeField.java