Uwe Gradenegger - Page 6 - Passionate about PKI

Details of the event with ID 1051 of the source Microsoft-Windows-TerminalServices-RemoteConnectionManager

Event Source:	Microsoft-Windows-TerminalServices-RemoteConnectionManager
Event ID:	1051 (0xC000041B)
Event log:	System
Event type:	Error
Event text (English):	The RD Session Host Server is configured to use SSL with user selected certificate, however, no usable certificate was found on the server. The default certificate will be used for RD Session Host Server authentication from now on. Please check the security settings by using the Remote Desktop Session Host Configuration tool in the Administrative Tools folder.
Event text (German):	The Remote Desktop session host server is configured to use SSL with a user-selected certificate, but no usable certificate was found on the server. From now on, the default certificate is used for Remote Desktop session host server authentication. Verify the security settings using the Remote Desktop Session Host Configuration tool in the Administrative Tools folder.

Basics: Replacing (Superseding) Certificate Templates

With the introduction of version 2 certificate templates along with Windows XP and Windows Server 2003, the option was introduced for a certificate template to replace one or more others.

This makes it possible to replace issued certificates with those of another certificate template, or to consolidate multiple certificate templates into a single one.

Basics: Cryptographic Service Provider (CSP) and Key Storage Provider (KSP)

Since Windows NT 4.0, the Cryptographic Service Provider (CSP) has been part of the CryptoAPI.

The purpose is that an application does not have to worry about the concrete implementation of key management, but can leave this to generic operating system interfaces. It is also intended to prevent cryptographic keys from being loaded into memory in the security context of the user/application being used (a fatal security incident based precisely on this problem was the Heartbleed incident).

For example, it makes no technical difference to the certification authority software how its private key is protected - whether in software or with a hardware security module (HSM), for example. The call of the private key is always identical for the certification authority.

With Windows Vista and the introduction of Cryptography Next Generation (CNG) as a replacement for CryptoAPI, Key Storage Providers (KSP) were introduced.

Remote desktop certificate request fails with error message "The permissions on the certificate template do not allow the current user to enroll for this type of certificate."

Assume the following scenario:

Machines are configured by group policy to request certificates for the remote desktop session host.
However, the certificates are not applied for.
In the event log of the affected system, the Event with ID 1064 of source Terminalservices-RemoteConnectionManager logged:

The RD Session Host server cannot install a new template-based certificate to be used for Transport Layer Security (TLS) 1.0\Secure Sockets Layer (SSL) authentication and encryption. The following error occurred: The permissions on the certificate template do not allow the current user to enroll for this type of certificate.

Remote desktop certificate request fails with error message "The requested certificate template is not supported by this CA."

Assume the following scenario:

Machines are configured by group policy to request certificates for the remote desktop session host.
However, the certificates are not applied for or existing certificates expire without renewal.
In the event log of the affected system, the event with ID 1064 of the source Terminalservices-RemoteConnectionManager is logged:

The RD Session Host server cannot install a new template-based certificate to be used for Transport Layer Security (TLS) 1.0\Secure Sockets Layer (SSL) authentication and encryption. The following error occurred: The requested certificate template is not supported by this CA.

The local certificate store for trusted root certificate authorities is not synchronized from Active Directory

Assume the following scenario:

A certification authority hierarchy is established in the network and the root certification authority is mapped in the configuration partition of the Active Directory forest.
Domain members are configured to run the autoenrollment process to update trusted root certificate authorities from the Configuration partition.
However, this process does not work for some clients. The root CA certificates are not automatically downloaded and entered into the local trust store.
As a consequence certificate requests can failbecause, for example, the certification authority hierarchy is not trusted.

Certificate requests for the online responder (OCSP) fail sporadically with error message "The revocation function was unable to check revocation for the certificate. 0x80092012 (-2146885614 CRYPT_E_NO_REVOCATION_CHECK)"

Assume the following scenario:

An online responder (OCSP) is set up in the network.
The certification authorities report at irregular intervals that certificate requests for the OCSP password signing certificates fail with the following error message:

The revocation function was unable to check revocation for the certificate. 0x80092012 (-2146885614 CRYPT_E_NO_REVOCATION_CHECK).

Extensive whitepaper about attacks on and with Microsoft PKI published

Will Schroeder and Lee Christensen, under the title "Certified Pre-Owned - Abusing Active Directory Certificate Services" a comprehensive Whitepaper about attacks on the Microsoft PKI and with the Microsoft PKI, and announced to talk about it at this year's BlackHat (07/31/2021 to 08/05/2021) to report.

Almost in parallel to this, the article "Microsoft ADCS - Abusing PKI in Active Directory Environment" by Jean Marsault published.

Programmatically trigger the autoenrollment process for the logged-in user

Assume the following scenario:

You write a script or an application that should trigger the autoenrollment process for the currently logged in user.
You will find out that the scheduled task cannot be executed.
The error message reads:

The user account does not have permissions to run this task.

Enable logging for automatic certificate request (autoenrollment)

The following is an overview of the Windows Event Viewer events generated for Windows certificate clients, their activation, and their identification.

Troubleshooting for automatic certificate request (autoenrollment) via RPC/DCOM

Assume the following scenario:

A certificate template is configured for automatic certificate request (autoenrollment).
The certificate template is published on a certification authority (Enterprise Certification Authority) integrated into Active Directory.
However, the users or computers configured for automatic Certificate Enrollment do not apply for certificates as intended.

The following is a troubleshooting guide.

Details of the event with ID 1 of the source Microsoft-Windows-CertificateServicesClient

Event Source:	Microsoft-Windows-CertificateServicesClient
Event ID:	1 (0x1)
Event log:	Application
Event type:	Information
Event text (English):	Certificate Services Client has been started successfully.
Event text (German):	The certificate service client was started successfully.

Details of the event with ID 502 of the source Microsoft-Windows-CertificateServicesClient

Event Source:	Microsoft-Windows-CertificateServicesClient
Event ID:	502 (0x1F6)
Event log:	Application
Event type:	Warning
Event text (English):	Certificate Services Client failed to register Group Policy notifications. Error code: %1.
Event text (German):	Error registering group policy notifications by the certificate service client. Error code: %1.

Details of the event with ID 4 of the source Microsoft-Windows-CertificateServicesClient

Event Source:	Microsoft-Windows-CertificateServicesClient
Event ID:	4 (0x4)
Event log:	Application
Event type:	Information
Event text (English):	Certificate Services Client has detected network dis-connectivity.
Event text (German):	No network connectivity was detected by the certificate service client.

Details of the event with ID 2 of the source Microsoft-Windows-CertificateServicesClient

Event Source:	Microsoft-Windows-CertificateServicesClient
Event ID:	2 (0x2)
Event log:	Application
Event type:	Information
Event text (English):	Certificate Services Client has been stopped.
Event text (German):	The certificate service client has been stopped.