ASP.NET 2.0: A Developeramp;#039;s Notebook [Electronic resources] نسخه متنی

5.5. Let Users Change Passwords

Note: Allow users to change their passwords via the
ChangePassword control.

Changing passwords is
another
common task performed by users of a web site. ASP.NET 2.0 has
replaced the mundane task of writing low-level code to change
passwords with a brand new ChangePassword control.

5.5.1. How do I do that?

In this lab, you will create a page that allows users to change their
passwords. You will use the ChangePassword control to do the work.
You will create a new Web Form in the restricted
Members folder so that authenticated users can
change their passwords.

Using the project created in the previous lab
(C:\ASPNET20\chap-5-SecurityControls), drag and
drop the ChangePassword control onto the
MemberDefault.aspx Web Form located in the
Members folder.

Apply the Elegant scheme to the ChangePassword control (through the
Auto Format... link in the ChangePassword Tasks menu). The
ChangePassword control will now look like that shown in Figure 5-21.

Figure 5-21. The ChangePassword control

The ChangePassword control must be used on a form that is located
within an authenticated directory so that it is accessible only after
a user has logged in.

Press F5 to test the application. You will need to be authenticated
first, so log in using the account created in the lab Section 5.2. After authentication, the
MemberDefault.aspx page will be displayed. Enter
the current password and the new password. Click the Change Password
button to change the password.

If the password is changed successfully, you will see the
notification shown in Figure 5-22.

Figure 5-22. Changing password using the ChangePassword control

Tip: You need to set the ContinueDestinationPageUrl property of the
ChangePassword control so that when the Continue button is clicked,
the user can be redirected to another page. It's a
good idea to set the property to point to the home page of your site.

If the new passwords do not match, an error message will be displayed
(see Figure 5-23).

Figure 5-23. Error in changing the password

5.5.2. What about...

...adding regular expressions to ensure that
the user's new password is of a certain length and
complexity?

You can do this by adding a NewPasswordRegularExpression attribute to
the <asp:changepassword> element (in Source View):

<asp:changepassword id="ChangePassword2" runat="server"
PasswordHintText = "Password must be 8 characters long 
and includes two numbers and two 
special character."
NewPasswordRegularExpression =
'@\"(?=.{8,})(?=(.*\d){2,})(?=(.*\W){2,})' 
NewPasswordRegularExpressionErrorMessage=
"Error: Your password must be 8 characters long
and includes two numbers and two special character." >
</asp:changepassword>

If you apply the Elegant scheme to the ChangePassword control, it
will appear like Figure 5-24 during runtime (shown
displaying the different error messages).

Figure 5-24. The ChangePassword control with the error messages

5.5.3. Where can I learn more?

For more information on using
regular expressions for pattern matching, check out the book
Mastering Regular Expressions by Jeffrey E. F.
Friedl (O'Reilly).