ViewStateUserKey & Doppia Invia Cookie
A partire da Visual Studio 2012, Microsoft ha aggiunto la protezione incorporata CSRF a nuovi progetti di applicazioni Web Form. Per utilizzare questo codice, aggiungere una nuova applicazione Web Form ASP .NET alla soluzione e visualizzare il codice Site.Master dietro la pagina. Questa soluzione applicherà la protezione CSRF a tutte le pagine di contenuto che ereditano dalla pagina Site.Master.
I seguenti requisiti devono essere soddisfatti per questa soluzione per lavorare:
Tutti i moduli web che fanno modifiche ai dati deve utilizzare la pagina di Site.master. Tutte le richieste di modifica dei dati devono utilizzare ViewState. Il sito Web deve essere libero da tutte le vulnerabilità di Cross-Site Scripting (XSS). Scopri come risolvere Cross-Site Scripting (XSS) utilizzando la Libreria di protezione Web di Microsoft .NET per i dettagli.
public partial class SiteMaster : MasterPage
{
private const string AntiXsrfTokenKey = "__AntiXsrfToken";
private const string AntiXsrfUserNameKey = "__AntiXsrfUserName";
private string _antiXsrfTokenValue;
protected void Page_Init(object sender, EventArgs e)
{
//First, check for the existence of the Anti-XSS cookie
var requestCookie = Request.Cookies[AntiXsrfTokenKey];
Guid requestCookieGuidValue;
//If the CSRF cookie is found, parse the token from the cookie.
//Then, set the global page variable and view state user
//key. The global variable will be used to validate that it matches
//in the view state form field in the Page.PreLoad method.
if (requestCookie != null
&& Guid.TryParse(requestCookie.Value, out requestCookieGuidValue))
{
//Set the global token variable so the cookie value can be
//validated against the value in the view state form field in
//the Page.PreLoad method.
_antiXsrfTokenValue = requestCookie.Value;
//Set the view state user key, which will be validated by the
//framework during each request
Page.ViewStateUserKey = _antiXsrfTokenValue;
}
//If the CSRF cookie is not found, then this is a new session.
else
{
//Generate a new Anti-XSRF token
_antiXsrfTokenValue = Guid.NewGuid().ToString("N");
//Set the view state user key, which will be validated by the
//framework during each request
Page.ViewStateUserKey = _antiXsrfTokenValue;
//Create the non-persistent CSRF cookie
var responseCookie = new HttpCookie(AntiXsrfTokenKey)
{
//Set the HttpOnly property to prevent the cookie from
//being accessed by client side script
HttpOnly = true,
//Add the Anti-XSRF token to the cookie value
Value = _antiXsrfTokenValue
};
//If we are using SSL, the cookie should be set to secure to
//prevent it from being sent over HTTP connections
if (FormsAuthentication.RequireSSL &&
Request.IsSecureConnection)
{
responseCookie.Secure = true;
}
//Add the CSRF cookie to the response
Response.Cookies.Set(responseCookie);
}
Page.PreLoad += master_Page_PreLoad;
}
protected void master_Page_PreLoad(object sender, EventArgs e)
{
//During the initial page load, add the Anti-XSRF token and user
//name to the ViewState
if (!IsPostBack)
{
//Set Anti-XSRF token
ViewState[AntiXsrfTokenKey] = Page.ViewStateUserKey;
//If a user name is assigned, set the user name
ViewState[AntiXsrfUserNameKey] =
Context.User.Identity.Name ?? String.Empty;
}
//During all subsequent post backs to the page, the token value from
//the cookie should be validated against the token in the view state
//form field. Additionally user name should be compared to the
//authenticated users name
else
{
//Validate the Anti-XSRF token
if ((string)ViewState[AntiXsrfTokenKey] != _antiXsrfTokenValue
|| (string)ViewState[AntiXsrfUserNameKey] !=
(Context.User.Identity.Name ?? String.Empty))
{
throw new InvalidOperationException("Validation of " +
"Anti-XSRF token failed.");
}
}
}
}
fonte
2015-04-30 07:53:13
possibile duplicato di [Prevenzione contraffazione richiesta tra siti] (http: // stackoverflow.it/questions/24675779/prevent-cross-site-request-forgery) – SilverlightFox
@SilverlightFox, Hope not;) –