Client Certificate Support

In addition to Kerberos, the AD/LDAP Connector also allows users to authenticate using client certificates. With this, users authenticate with a certificate installed on their machine or device.

Configure the AD/LDAP connection

To activate client certificates on an AD/LDAP connection:

  1. Go to Connections > Enterprise and select your AD/LDAP connection.
  2. Toggle the Use client SSL certificate authentication option in the settings.
  3. Provide IP address ranges in the IP Ranges field. Only users coming from the given IP ranges are prompted to authenticate using client certificates. Users from different IP ranges are prompted to login with the username/password login form.

Configure the certificates

Once the AD/LDAP connection has been configured in Auth0, you'll need to configure the certificates in the AD/LDAP Connector. Supporting client certificates will require the following:

  1. An SSL certificate for the Front Facing Url, because the interaction between the end user and the Connector will need to happen over HTTPS.
  2. One or more CA certificates.
  3. A Client Certificate signed by the CA for each user that needs to authenticate using Client Certificates.

Before uploading certificates to the AD/LDAP connector, convert X509 certificates to Base64. To do this you can use a simple online tool like this one, or you can use Certutil.exe on Windows Server.

The SSL certificate and the CA certificate can be uploaded in the AD/LDAP Connector:

For testing purposes you can generate your own self-signed CA and Client Certificates using makecert.exe on Windows, which is part of the Windows SDK:

The important part here is that the Client Certificate's subject must be in the format of CN=AD_USERNAME, eg: CN=jon.

End User

In an application we might now start the sign in flow using an AD/LDAP Connection:

If the user's IP address falls within the configured IP Range, they'll be prompted to authenticate with a Client Certificate:

Choose Client Certificate

After choosing the certificate the AD/LDAP Connector will validate it and the user will be logged in:

Signed In using Client Certificates