public string AntiForgeryToken(string salt, string domain, string path)
{
string formValue = GetAntiForgeryTokenAndSetCookie(salt, domain, path);
string fieldName = AntiForgeryData.GetAntiForgeryTokenName(null);
TagBuilder builder = new TagBuilder("input");
builder.Attributes["type"] = "hidden";
builder.Attributes["name"] = fieldName;
builder.Attributes["value"] = formValue;
return(builder.ToString(TagRenderMode.SelfClosing));
}
public void OnAuthorization(AuthorizationContext filterContext)
{
if (filterContext == null)
{
throw new ArgumentNullException("filterContext");
}
string fieldName = AntiForgeryData.GetAntiForgeryTokenName(null);
string cookieName = AntiForgeryData.GetAntiForgeryTokenName(filterContext.HttpContext.Request.ApplicationPath);
HttpCookie cookie = filterContext.HttpContext.Request.Cookies[cookieName];
if (cookie == null || String.IsNullOrEmpty(cookie.Value))
{
// error: cookie token is missing
throw CreateValidationException();
}
AntiForgeryData cookieToken = Serializer.Deserialize(cookie.Value);
string formValue = filterContext.HttpContext.Request.Form[fieldName];
if (String.IsNullOrEmpty(formValue))
{
// error: form token is missing
throw CreateValidationException();
}
AntiForgeryData formToken = Serializer.Deserialize(formValue);
if (!String.Equals(cookieToken.Value, formToken.Value, StringComparison.Ordinal))
{
// error: form token does not match cookie token
throw CreateValidationException();
}
string currentUsername = AntiForgeryData.GetUsername(filterContext.HttpContext.User);
if (!String.Equals(formToken.Username, currentUsername, StringComparison.OrdinalIgnoreCase))
{
// error: form token is not valid for this user
// (don't care about cookie token)
throw CreateValidationException();
}
if (!ValidateFormToken(formToken))
{
// error: custom validation failed
throw CreateValidationException();
}
}
private string GetAntiForgeryTokenAndSetCookie(string salt, string domain, string path)
{
string cookieName = AntiForgeryData.GetAntiForgeryTokenName(ViewContext.HttpContext.Request.ApplicationPath);
AntiForgeryData cookieToken;
HttpCookie cookie = ViewContext.HttpContext.Request.Cookies[cookieName];
if (cookie != null)
{
cookieToken = Serializer.Deserialize(cookie.Value);
}
else
{
cookieToken = AntiForgeryData.NewToken();
string cookieValue = Serializer.Serialize(cookieToken);
HttpCookie newCookie = new HttpCookie(cookieName, cookieValue)
{
HttpOnly = true, Domain = domain
};
if (!String.IsNullOrEmpty(path))
{
newCookie.Path = path;
}
ViewContext.HttpContext.Response.Cookies.Set(newCookie);
}
AntiForgeryData formToken = new AntiForgeryData(cookieToken)
{
CreationDate = DateTime.Now,
Salt = salt
};
string formValue = Serializer.Serialize(formToken);
return(formValue);
}
