Why ActiveX “Unknown Publisher” error when using signed certificate?

Question

I have been struggling for days trying to get a simple ActiveX DLL to work with no success despite studying several articles on the subject which I have found online.

I suspect I have several things coded incorrectly as I am just not familiar with this and most of the articles on the subject are out of date. I am using Visual Studio 2008 and have been using the Windows SDK v7.1 for digital signing.

What I am trying to do is return the client machineName from the environment class back to the web page (and eventually back to the web server).

This is my C# class:

using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using Microsoft.Win32;

namespace GetClientInfo101
{
    [Guid("121C3E0E-DC6E-45dc-952B-A6617F0FAA32")]
    [InterfaceType(ComInterfaceType.InterfaceIsDual)]
    [ComVisible(true)]
    public interface IGetClient
    {
        [DispId(1)]
        string GetClient();
    }
    [Guid("5085C918-0236-4828-BDFA-063FEE57C69B")]
    [ProgId("getClientInfoAx.CGetClient")]
    [ClassInterface(ClassInterfaceType.None)]
    [ComDefaultInterface(typeof(IGetClient))]
    [System.ComponentModel.ToolboxItem(true)]
    [ComVisible(true)]
    public class CGetClient : IGetClient
    {
        public string GetClient()
        {
           return Environment.MachineName;
        }
    }
}

Here is my assembly:

using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;

// General Information about an assembly is controlled through the following
// set of attributes. Change these attribute values to modify the information
// associated with an assembly.
[assembly: AssemblyTitle("GetClientInfo101")]
[assembly: AssemblyDescription("")]
[assembly: AssemblyConfiguration("")]
[assembly: AssemblyCompany("")]
[assembly: AssemblyProduct("GetClientInfo101")]
[assembly: AssemblyCopyright("Copyright © N/A 2010")]
[assembly: AssemblyTrademark("")]
[assembly: AssemblyCulture("")]

// Setting ComVisible to false makes the types in this assembly not visible
// to COM components.  If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(false)]

// The following GUID is for the ID of the typelib if this project is exposed to COM
[assembly: Guid("1bf2a0bc-f9cb-4f68-8990-5caaf3ab525d")]

// Version information for an assembly consists of the following four values:
[assembly: AssemblyVersion("1.0.0.0")]
[assembly: AssemblyFileVersion("1.0.0.0")

Here is my object tag and script on my website Master Page. **NOTE: I am getting the error

Microsoft JScript runtime error: Automation server can't create object

on the "var" execution**:

<object id="getClientInfo" name="GetClientInfo101" classid="clsid:5085C918-0236-4828-BDFA-063FEE57C69B"
        codebase="GetClientInfo/GetClientInfoAX.cab#version=1,0,0,0">
</object>

<script type="text/javascript">
    function OpenActiveX()
    {
        var objGetClientInfo = new ActiveXObject("GetClientInfoAx.CGetClient");
        if(objGetClientInfo != null)
         {
             //For testing only
             alert(objGetClientInfo.GetClient());
         }
     }
</script>

Then I have manually created a .inf file as follows:

[version]
    signature="$CHICAGO$"
    AdvancedINF=2.0
[Add.Code]
    GetClientInfo101.dll=GetClientInfo101.dll
    GetClientInfo101.inf=GetClientInfo101.inf
[GetClientInfo101.dll]
    file-win32-x86=thiscab
    clsid={5085C918-0236-4828-BDFA-063FEE57C69B}
    FileVersion=1,0,0,0
    RegisterServer=yes
[GetClientInfo101.inf]
    file=thiscab

However, when I build my .cab file I am also getting a .OSD file output to the .cab as follows (I am concerned about there being both a .inf and a .OSD file in the same .cab file. Is that right and will it cause problems? I am not sure how to tell Visual Studio to NOT build the .OSD file.

<?XML version="1.0" ENCODING='UTF-8'?>
<!DOCTYPE SOFTPKG SYSTEM "http://www.microsoft.com/standards/osd/osd.dtd">
<?XML::namespace href="http://www.microsoft.com/standards/osd/msicd.dtd" as="MSICD"?>
<SOFTPKG NAME="GetClientInfoAX" VERSION="1,0,0,0">
    <TITLE> GetClientInfoAX </TITLE>
    <MSICD::NATIVECODE>
        <CODE NAME="GetClientInfo101">
            <IMPLEMENTATION>
                <CODEBASE FILENAME="GetClientInfo101.dll">
                </CODEBASE>
            </IMPLEMENTATION>
        </CODE>
    </MSICD::NATIVECODE>
</SOFTPKG>

Anyway, this has been a nightmare trying to piece together all the details of this. I would be very grateful for any help resolving this.

OK, the The Code Project article A Complete Scriptable ActiveX Web Control Tutorial Using ATL is what I used as a guide for the signing the .cab file. See the section titled "Signing a cab file".

Here are the commands I used. Note that I used Visual Studio to create the cab file instead of CABARC. Also note I am only using a test cert:

makecert -sv "getclientinfocert.pvk" -n "CN=My Company" getclientinfocert.cer

cert2spc getclientinfocert.cer getclientinfocert.spc

pvk2pfx -pvk getclientinfocert.pvk -pi AOTC20467cert -spc getclientinfocert.spc -pfx getclientinfocert.pfx -po AOTC81396pass –f

signtool sign /f getclientinfocert.pfx /p AOTC81396pass /t http://timestamp.verisign.com/scripts/timstamp.dll /v GetClientInfo101.dll

signtool sign /f getclientinfocert.pfx /p AOTC81396pass /t http://timestamp.verisign.com/scripts/timstamp.dll /v GetClientInfoAX.cab

Use certmgr to export and import “Root Agency” certificate to Trusted Root Certs:

signtool verify /v /a GetClientInfoAX.cab

Note that I copied my DLL to my Windows SDK folder, signed that, copied it back to my cab file which I then copied over to my SDK file, signed the cab file. Then finally, I copied the cab file to my website project.

NOTE: See comments at end of first answer. I have purchased a signed certificate from Comodo and with that installed, I now get "Unknown Publisher" error even though the certificate status is "OK". Both the DLL and CAB file have been signed.

I believe my issue now is that the control needs to be marked as safe for scripting. I found a recent article, Creating an ActiveX control in .NET using C#, which looks very helpful.

Answer 1

Your version independent progid in the ComVisible co class is set as

  [ProgId("getClientInfoAx.CGetClient")] 

Whereas in the JScript Code the instantiation code is as

  var objGetClientInfo = new ActiveXObject("GetClientInfoAx.CGetClient");

Please verify case sensitivity first and confirm behavior?