How to give ASP.NET access to a private key in a certificate in the certificate store?
- by thames
I have an ASP.NET application that accesses private key in a certificate in the certificates store. On Windows Server 2003 I was able to use winhttpcertcfg.exe to give private key access to the NETWORK SERVICE account. How do I give permissions to access a Private Key in a certificate in the certificate store (Local Computer\Personal) on a Windows Server 2008 R2 in an IIS 7.5 website?
I've tried giving Full Trust access to "Everyone", "IIS AppPool\DefaultAppPool", "IIS_IUSRS", and everyother security account I could find using the Certificates MMC (Server 2008 R2). However the below code demonstrates that the code does not have access to the Private Key of a certificate that was imported with the private key. The code instead throws and error everytime the private key property is accessed.
Default.aspx
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<%@ Import Namespace="System.Security.Cryptography.X509Certificates" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:Repeater ID="repeater1" runat="server">
<HeaderTemplate>
<table>
<tr>
<td>
Cert
</td>
<td>
Public Key
</td>
<td>
Private Key
</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td>
<%#((X509Certificate2)Container.DataItem).GetNameInfo(X509NameType.SimpleName, false) %>
</td>
<td>
<%#((X509Certificate2)Container.DataItem).HasPublicKeyAccess() %>
</td>
<td>
<%#((X509Certificate2)Container.DataItem).HasPrivateKeyAccess() %>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table></FooterTemplate>
</asp:Repeater>
</div>
</form>
</body>
</html>
Default.aspx.cs
using System;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Web.UI;
public partial class _Default : Page
{
public X509Certificate2Collection Certificates;
protected void Page_Load(object sender, EventArgs e)
{
// Local Computer\Personal
var store = new X509Store(StoreLocation.LocalMachine);
// create and open store for read-only access
store.Open(OpenFlags.ReadOnly);
Certificates = store.Certificates;
repeater1.DataSource = Certificates;
repeater1.DataBind();
}
}
public static class Extensions
{
public static string HasPublicKeyAccess(this X509Certificate2 cert)
{
try
{
AsymmetricAlgorithm algorithm = cert.PublicKey.Key;
}
catch (Exception ex)
{
return "No";
}
return "Yes";
}
public static string HasPrivateKeyAccess(this X509Certificate2 cert)
{
try
{
string algorithm = cert.PrivateKey.KeyExchangeAlgorithm;
}
catch (Exception ex)
{
return "No";
}
return "Yes";
}
}
