Uwe Gradenegger - Page 51 - Uwe Gradenegger

Role configuration for Network Device Enrollment Service (NDES) fails with error message "CMSCEPSetup::Install: The system cannot find the path specified. 0x80070003 (WIN32: 3 ERROR_PATH_NOT_FOUND)".

Assume the following scenario:

One installs a Network Device Enrollment Service (NDES) server.
The role configuration fails with the following error message:

CMSCEPSetup::Install: The system cannot find the path specified. 0x80070003 (WIN32: 3 ERROR_PATH_NOT_FOUND)

The Network Device Enrollment Service (NDES) Administration web page (certsrv/mscep_admin) reports "The password cache is full."

Assume the following scenario:

An NDES server is configured on the network.
When calling the administration web page (certsrv/mscep_admin) the following message appears:

The password cache is full.

What key lengths should be used for certificate authorities and certificates?

When planning a public key infrastructure, the question naturally arises as to which key lengths should be selected for certification authority and end certificates.

Generating a RFC 2818 compliant certificate request for SSL certificates

Google is a major player with the Chromium project and products based on it such as Google Chrome and Microsoft Edge have moved to implement the RFC 2818 and to no longer trust certificates that no longer fulfill the RFC.

For us, the following sentence is of great explosiveness:

If a subjectAltName extension of type dNSName is present, that MUST be used as the identity. Otherwise, the (most specific) Common Name field in the Subject field of the certificate MUST be used. Although the use of the Common Name is existing practice, it is deprecated and Certification Authorities are encouraged to use the dNSName instead
https://tools.ietf.org/html/rfc2818

Configure Device Template for Network Device Enrollment Service (NDES)

By default, the Network Device Enrollment Service (NDES) requests certificates from the "IPsec (Offline Request)" template. This certificate template is from Windows 2000 times and cannot be edited. Therefore, it is recommended to change the default settings and use your own certificate templates that serve your personal requirements.

Enabling Secure Sockets Layer (SSL) for the Network Device Enrollment Service (NDES).

In the default configuration, the Network Device Enrollment Service (NDES) only accepts unencrypted connections via HTTP. It is recommended that at least the NDES administration web page be configured for HTTP over TLS (HTTPS) to make it difficult to capture network traffic. The following is a guide.

For a closer look at the need to use SSL, see the article "Should HTTPS be used for the Network Device Enrollment Service (NDES)?„.

Moving Network Device Enrollment Service (NDES) to another certification authority

Assume the following scenario:

There is one NDES instance installed on the network.
The Certification Authority issuing to NDES is to be changed.

The official statement on this is that NDES must be reinstalled and reconfigured in this case. However, this is not necessary. The necessary steps are described below.

Installing the Network Device Enrollment Service (NDES) without Enterprise Administrator permissions

Assume the following scenario:

One installs a Network Device Enrollment Service (NDES) server.
The role configuration fails with the following error message:

Insufficient access rights to perform this operation. 0x80072098 (WIN32: 8344 ERROR_DS_INSUFF_ACCESS_RIGHTS

Typically, the NDES roll configuration requires, that the installing user is a member of the Enterprise Admins group. However, this is not technically necessary and contradicts Microsoft's security hardening recommendations, since NDES is not (necessarily) a system that is assigned to the highest security layer (Tier-0).

Below is a way to configure the NDES role even without the required permissions.

Role configuration for Network Device Enrollment Service (NDES) fails with error message "CMSCEPSetup::SetMSCEPSetupProperty: Access is denied. 0x80070005 (WIN32: 5 ERROR_ACCESS_DENIED)".

Assume the following scenario

One installs a Network Device Enrollment Service (NDES) server
The role configuration fails with the following error message:

CMSCEPSetup::SetMSCEPSetupProperty: Access is denied. 0x80070005 (WIN32: 5 ERROR_ACCESS_DENIED)

Using custom Registration Authority (RA) certificate templates for the Network Device Enrollment Service (NDES).

The Network Device Enrollment Service (NDES) uses two certificate templates for its internal function to make it act as a Registration Authority (RA). These are published during role configuration of the NDES service on the configured certificate authority and certificates are requested:

CEP Encryption
Exchange Enrollment Agent (Offline Request)

These certificate templates are standard templates from the Windows 2000 world (version 1 templates), i.e. they cannot be edited. In addition, the Exchange Enrollment Agent (Offline Request) template is marked as a user template, i.e. during NDES role configuration the certificate is requested in the context of the installing user and then imported into the machine store. At the latest when the certificates are to be renewed after two years, things get complicated here.

It is therefore a good idea to use your own certificate templates for NDES. These can be adapted in terms of their key length, for example. The use of hardware security modules (HSM) is also possible in this way. Even automatic renewal can be configured.

When installing a new certificate authority certificate, you get the error message "The revocation function was unable to check revocation for the certificate. 0x80092012 (-2146885614 CRYPT_E_NO_REVOCATION_CHECK)".

Assume the following scenario:

One installs a new certification authority certificate on the certification authority, either because the certification authority was newly installed, or because the certification authority certificate was renewed.
During the installation you get the following error message:

Cannot verify certificate chain. Do you wish to ignore the error and continue? The revocation function was unable to check revocation for the certificate. 0x80092012 (-2146885614 CRYPT_E_NO_REVOCATION_CHECK)

Publishing a certificate revocation list (CRL) fails with the error message "Insufficient access rights to perform the operation. 0x80072098 (WIN32: 8344 ERROR_DS_INSUFF_ACCESS_RIGHTS)".

Assume the following scenario:

An attempt is made to publish a new certificate revocation list (CRL) on a certification authority
The certificate authority is configured to publish the certificate revocation lists to Active Directory (LDAP CDP).
Publishing the certificate revocation list fails with the following error message:

Insufficient access rights to perform the operation. 0x80072098 (WIN32: 8344 ERROR_DS_INSUFF_ACCESS_RIGHTS)

Publishing a certificate revocation list (CRL) fails with the error message "Directory object not found. 0x8007208d (WIN32: 8333 ERROR_DS_OBJ_NOT_FOUND)".

Assume the following scenario:

An attempt is made to publish a new certificate revocation list (CRL) on a certification authority.
The certificate authority is configured to publish the certificate revocation lists to Active Directory (LDAP CDP).
Publishing the certificate revocation list fails with the following error message:

Directory object not found. 0x8007208d (WIN32: 8333 ERROR_DS_OBJ_NOT_FOUND)

Domain controller does not check extended key usage on smart card login

Anyone who wants to use the smartcard logon function in their company would be well advised to ensure that their certification authority has the strongest possible security hardening. This includes some essential measures:

Removing all unnecessary certification authority certificates from the NTAuthCertificates object in Active Directory: Each certification authority located in this store is authorized to issue smartcard logon certificates in Active Directory for the complete forest.
Use qualified subordinationRestricting the certification authority certificates so that they are only trusted for the extended key usages actually issued. In the event of a compromise of the certification authority, the damage is then limited to these extended key usages. The "Smart Card Logon" Extended Key Usage would then only be present in the certification authority certificate of the certification authority that actually issues such certificates.

What is interesting about these thoughts, however, is that the domain controllers do not check the extended key usages at all when logging in via smartcard.

Active Directory forest compromised by EDITF_ATTRIBUTESUBJECTALTNAME2 flag

In net circulate unfortunately much at many Instructions (also the big players are not excluded from this, not even Microsoft itself or the Grand Master Komar), which fatally recommends that the EDITF_ATTRIBUTESUBJECTALTNAME2 flag should be set on the certification authority - supposedly to be able to issue Subject Alternative Name (SAN) extension certificates for manually submitted certificate requests.

Unfortunately, this approach is not only unnecessary, it also has some unpleasant side effects, which in the worst case can help an attacker to take over the entire Active Directory forest.