@Override public ResponseMessage execute() { SessionManager sm = sessionManager; Session session = sm.getSession(sessionHandler); if (session == null) { return ResponseMessage.ErrorMessage("Bad session handler."); } Signer signer = session.getSigner(); try { signer.init(this.mechanism, this.privateKeyHandler); return ResponseMessage.OKMessage(); } catch (Exception e) { return ResponseMessage.ErrorMessage(e.getLocalizedMessage()); } }