Validates a user name and password against credentials stored in the configuration file for an application.
(in System.Web.dll)
Visual Basic (Declaration)
Public Shared Function Authenticate ( _
name As String, _
password As String _
) As Boolean
Dim name As String
Dim password As String
Dim returnValue As Boolean
returnValue = FormsAuthentication.Authenticate(name, _
password)
public static bool Authenticate(
string name,
string password
)
public:
static bool Authenticate(
String^ name,
String^ password
)
public static function Authenticate(
name : String,
password : String
) : boolean
Return Value
Type:
System..::.Boolean
true if the user name and password are valid; otherwise, false.
The Authenticate method verifies user credentials that are stored in the credentials section of the application configuration file. Alternatively, you can use ASP.NET membership to store user credentials and call the ValidateUser to verify the credentials. For more information, see Managing Users by Using Membership.
For improved security, you can encrypt passwords stored in the configuration file for an application by using the HashPasswordForStoringInConfigFile method.
The following code example shows user credentials stored in the Web.config file for an application. The password values have been hashed using the HashPasswordForStoringInConfigFile method.
<authentication mode="Forms">
<forms loginUrl="login.aspx">
<credentials passwordFormat="SHA1">
<user name="user1" password="27CE4CA7FBF00685AF2F617E3F5BBCAFF7B7403C" />
<user name="user2" password="D108F80936F78DFDD333141EBC985B0233A30C7A" />
<user name="user3" password="7BDB09781A3F23885CD43177C0508B375CB1B7E9"/>
</credentials>
</forms>
</authentication>
The following code example shows a login page that uses the Authenticate method to validate user credentials.
.gif) Security Note: |
|---|
This example contains a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview. |
<%@ Page Language="VB" %>
<%@ Import Namespace="System.Web.Security" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Public Sub Login_OnClick(sender As Object, args As EventArgs)
If FormsAuthentication.Authenticate(UsernameTextbox.Text, PasswordTextbox.Text) Then
FormsAuthentication.RedirectFromLoginPage(UsernameTextbox.Text, NotPublicCheckBox.Checked)
Else
Msg.Text = "Login failed. Please check your user name and password and try again."
End If
End Sub
</script>
<html >
<head>
<title>Login</title>
</head>
<body>
<form id="form1" runat="server">
<h3>Login</h3>
<asp:Label id="Msg" ForeColor="maroon" runat="server" /><br />
Username: <asp:Textbox id="UsernameTextbox" runat="server" /><br />
Password: <asp:Textbox id="PasswordTextbox" runat="server" TextMode="Password" /><br />
<asp:Button id="LoginButton" Text="Login" OnClick="Login_OnClick" runat="server" />
<asp:CheckBox id="NotPublicCheckBox" runat="server" />
Check here if this is <span style="text-decoration:underline">not</span> a public computer.
</form>
</body>
</html>
<%@ Page Language="C#" %>
<%@ Import Namespace="System.Web.Security" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
public void Login_OnClick(object sender, EventArgs args)
{
if (FormsAuthentication.Authenticate(UsernameTextbox.Text, PasswordTextbox.Text))
FormsAuthentication.RedirectFromLoginPage(UsernameTextbox.Text, NotPublicCheckBox.Checked);
else
Msg.Text = "Login failed. Please check your user name and password and try again.";
}
</script>
<html >
<head>
<title>Login</title>
</head>
<body>
<form id="form1" runat="server">
<h3>Login</h3>
<asp:Label id="Msg" ForeColor="maroon" runat="server" /><br />
Username: <asp:Textbox id="UsernameTextbox" runat="server" /><br />
Password: <asp:Textbox id="PasswordTextbox" runat="server" TextMode="Password" /><br />
<asp:Button id="LoginButton" Text="Login" OnClick="Login_OnClick" runat="server" />
<asp:CheckBox id="NotPublicCheckBox" runat="server" />
Check here if this is <span style="text-decoration:underline">not</span> a public computer.
</form>
</body>
</html>
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0, 1.1, 1.0
Reference
Other Resources