How to Implement Second Factor authentication in the SAP EP Portal

hi Team,

we have a requirement where when user logs in entering his user id and password, we have to navigate the page to the different page which prompts for OTP.

I downloaded the WAR File : tc~sec~ume~logon~ui.wa from the server i.e at the path :\usr\sap\ \J00\j2ee\cluster\apps\ sap.com\com.sap.security.core.logon\servlet_jsp\logon_ui_resources\

After importing this WAR file to the Studio, on opening logonPage.jsp , i can see Logon Button tag as shown below

<td align="right">	
													<!-- logon button -->
													<sap:button type="logon" styleClass="urBtnStdNew"/>
													<sap:if display="DisplayCancelButton">
														<!-- display cancel button incase of SP initiated SSO -->
														<sap:button type="cancelIdPLogon" styleClass="urBtnStdNew"/>																
													</sap:if>
												</td>

But am unable to find , on click of Logon which servlet is being called and which method we have to modify to impliment the second factor authentication.

Regards

Govardan Raj