Changes into SecurityProvider interface and Logout middleware (#660)

* Changes into SecurityProvider interface and Logout middleware to support SLO in angular.

* Keep old signature to avoid breaking interface.

Author: MBarnech

common/src/main/java/com/genexus/security/NoSecurityProvider.java

@@ -70,4 +70,10 @@ public void oauthgetuser(int remoteHandle, ModelContext context, String[] userJs
 	public void oauthlogout(int remoteHandle, ModelContext context)
 	{
 	}
+
+	public void oauthlogout(int remoteHandle, ModelContext context, String[] URL, short[] statusCode)
+	{
+		URL[0] = "";
+		statusCode[0] = -1;
+	}
 }

common/src/main/java/com/genexus/security/SecurityProvider.java

@@ -16,4 +16,5 @@ public interface SecurityProvider
 	GXResult oauthauthentication(int remoteHandle, ModelContext context, String grantType, String userName, String userPassword, String clientId, String clientSecret, String scope, String additional_parameters, OutData outData, String[] redirectURL, boolean[] flag);
 	void oauthgetuser(int remoteHandle, ModelContext context, String[] userJson, boolean[] isOK);
 	void oauthlogout(int remoteHandle, ModelContext context);
+	void oauthlogout(int remoteHandle, ModelContext context, String[] URL, short[] statusCode);
 }

java/src/main/java/com/genexus/webpanels/GXOAuthLogout.java

@@ -4,6 +4,7 @@
 import com.genexus.ModelContext;
 import com.genexus.internet.HttpContext;
 import com.genexus.security.GXSecurityProvider;
+import json.org.json.JSONObject;
 
 public class GXOAuthLogout extends GXWebObjectStub
 {   
@@ -14,15 +15,32 @@ protected void doExecute(HttpContext context) throws Exception
 		context.setStream();
 		try
 		{			
+			String genexus_agent = context.getHeader("Genexus-Agent");
+
 			ModelContext modelContext =  new ModelContext(Application.gxCfg);
 			modelContext.setHttpContext(context);
-			ModelContext.getModelContext().setHttpContext(context);
-			
-			GXSecurityProvider.getInstance().oauthlogout(-2, modelContext);
-			
+			ModelContext.getModelContext().setHttpContext(context);			
+			String[] URL = new String[] {""};
+			short[] statusCode = new short[]{0};
+			GXSecurityProvider.getInstance().oauthlogout(-2, modelContext, URL, statusCode);
+
+			if (statusCode[0] == 303)
+				context.getResponse().setStatus(200);
+			else
+				context.getResponse().setStatus(statusCode[0]);
+
 			context.getResponse().setContentType("application/json");
-			context.getResponse().setStatus(200);
-			context.writeText("{}");
+			JSONObject jObj = new JSONObject();
+			if (genexus_agent.equals("WebFrontend Application") && URL[0].length() > 0)
+			{				
+				context.getResponse().addHeader("GXLocation", URL[0]);			
+				jObj.put("GXLocation", URL[0]);
+			}
+			else
+			{
+				jObj.put("code", statusCode[0]);					
+			}
+			context.writeText(jObj.toString());
 			context.getResponse().flushBuffer();
 			return;			
 		}