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FormsAuthentication.Authenticate Method

Validates a user name and password against credentials stored in the configuration file for an application.

Namespace:  System.Web.Security
Assembly:  System.Web (in System.Web.dll)

public static bool Authenticate(
	string name,
	string password
)

Parameters

name
Type: System.String

The user name.

password
Type: System.String

The password for the user.

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.

Security noteSecurity 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="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 xmlns="http://www.w3.org/1999/xhtml" >
<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

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