CSRF Attack protection to all pages that inherit from the site.master page.
1. All web form pages data modification use the site.master page.
2. Al request data modification use Viewstste.
3. Website must be free from XSS vulnerabilities.
By using Microsoft . Net Protection Library
private const string AntiXsrfTokenKey = "__AntiXsrfToken";
private const string AntiXsrfUserNameKey = "__AntiXsrfUserName";
private string _antiXsrfTokenValue;
protected void Page_Init(object sender, EventArgs e)
{
// The code below helps to protect against XSRF attacks
var requestCookie = Request.Cookies[AntiXsrfTokenKey];
Guid requestCookieGuidValue;
if (requestCookie != null && Guid.TryParse(requestCookie.Value, out requestCookieGuidValue))
{
// Use the Anti-XSRF token from the cookie
_antiXsrfTokenValue = requestCookie.Value;
Page.ViewStateUserKey = _antiXsrfTokenValue;
}
else
{
// Generate a new Anti-XSRF token and save to the cookie
_antiXsrfTokenValue = Guid.NewGuid().ToString("N");
Page.ViewStateUserKey = _antiXsrfTokenValue;
var responseCookie = new HttpCookie(AntiXsrfTokenKey)
{
HttpOnly = true,
Value = _antiXsrfTokenValue
};
if (FormsAuthentication.RequireSSL && Request.IsSecureConnection)
{
responseCookie.Secure = true;
}
Response.Cookies.Set(responseCookie);
}
Page.PreLoad += master_Page_PreLoad;
}