UserLogin | Security Functions

Logs a user into the Citect SCADA system, using either Windows integrated security or Citect SCADA security and gives users access to the areas and privileges assigned to them in the Users database, and uses the locale language defined for that user. Only one user can be logged into a computer at any one time. If a user is already logged in when a second user logs in, the first user is replaced by the newly logged on user. When a newly logged in user does not have access to view the current page (as defined by the page's area), the system returns to the home page as specified by the parameter[Page]HomePage, and if unsuccessful that returns to the startup page. When multiple pages are currently displayed, this occurs for each open window.

To call this function at user login, the password argument passed needs to be in secure string format.

At startup, or when the user logs out, a default user is active, with access to area 0 (zero) and privilege 0 (zero) only. Use the LoginForm() function to display a form for logging in to the system.

This function is a blocking function. It blocks the calling Cicode task until the operation is complete.

The user's name as defined in the Users database, or the Windows User account name, in plain text.

The user's password, as defined in the Users database or Windows account formatted as a secure string.

To improve the user credentials protection provides a system built-in user login function that takes the user name and secure password as the arguments. This reduces the chance that the user's password can be exposed in plaint text from the runtime system

The specified language needs to tagbe one of the languages defined in System/Languages (LANG.DBF). If the specified language is undefined, the default language is used by the login user, and a message "Undefined language" is shown in the prompt line.

An empty string (i.e. "") can be specified to indicate that the default language is used by the login user. The default language defined by [Language]LocalLanguage INI parameter.

	/*
	** FUNCTION NAME:LoginForm
	**
	** This function displays the login form, get the user name, password and
	** the language of the user session and then trys to log the user in. 
	** If the login does not succeed it will retry until login is ok or user 
	** presses the cancel button.
	**
	*/

	INT
	FUNCTION
	LoginForm(STRING sName="", STRING sPassword="", STRING sLanguage="English")
	INT	bDone;
	INT	nStatus;
	INT	hForm;

	bDone = FALSE;
	WHILE bDone = FALSE DO
		FormNew("@(Login Form)", 35, 5, 5);
		FormPrompt(1, 0, "@(Name)");
		FormInput(16, 0, "", sName, 16);
		FormPrompt(1, 2, "@(Password)");
		FormSecurePassword(18, 2, "", sPassword, 16);
		FormPrompt(1, 4, "@(Language)");
		FormInput(16, 4, sLanguage, 16);			
		FormButton(6, 6, "  " + "@(OK)" + "  ", 0, 1);
		FormButton(20, 6, "@(Cancel)", 0, 2);

	IF FormRead(0) = 0 THEN
		hForm = FormNew("@(User Login)", 36, 1, 8 + 16 + 128 + 256);
		FormPrompt(1, 0, "@(Authentication in progress ...)");
		FormRead(1);
		SleepMs(200);

		IF UserLogin(sName, sPassword, sLanguage) = 0 THEN
		         bDone = TRUE
		         nStatus = 0;
		ELSE
		         sPassword = ""; 
	END

		IF FormActive(hForm) THEN
		         FormDestroy(hForm);
		         END
		ELSE
		         bDone = TRUE;
				 nStatus = 298;
		  END
		END
		RETURN nStatus;
	END