public TOTPGenerator.Mode getMode() throws GuacamoleException {
        return environment.getProperty(TOTP_MODE, TOTPGenerator.Mode.SHA1);
    }
Returns the hash algorithm that should be used to generate TOTP codes. If
not specified, SHA1 will be used by default.

@return
    The hash algorithm that should be used to generate TOTP codes.

@throws GuacamoleException
    If the "totp-mode" property cannot be read from
    guacamole.properties.
extensions/guacamole-auth-totp/src/main/java/org/apache/guacamole/auth/totp/conf/ConfigurationService.java