Prerequisites - Amazon Directory Service
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To enable certificate-based mutual Transport Layer Security (mTLS) authentication using smart cards for the Amazon WorkSpaces client, you need an operational smart card infrastructure integrated with your self-managed Active Directory. For more information on how to set up smart card authentication with Amazon WorkSpaces and Active Directory, see the Amazon WorkSpaces Administration Guide.

Before you enable smart card authentication for WorkSpaces, please review the following considerations:

CA certificate requirements

AD Connector requires a certificate authority (CA) certificate, which represents the issuer of your user certificates, for smart card authentication. AD Connector matches CA certificates with the certificates presented by your users with their smart cards. Note the following CA certificate requirements:

  • Before you can register a CA certificate, it must be more than 90 days away from expiration.

  • CA certificates must be in Privacy-Enhanced Mail (PEM) format. If you export CA certificates from inside Active Directory, choose Base64-encoded X.509 (.CER) as the export file format.

  • All root and intermediary CA certificates that chain from an issuing CA to user certificates must be uploaded for smart card authentication to succeed.

  • A maximum of 100 CA certificates can be stored per AD Connector directory

  • AD Connector does not support the RSASSA-PSS signature algorithm for CA certificates.

  • Verify the Certificate Propagation Service is set to Automatic and running.

User certificate requirements

The following are some of the requirements for the user certificate:

  • The user’s smart card certificate has a Subject Alternative Name (SAN) of the user’s userPrincipalName (UPN).

  • The user’s smart card certificate has Enhanced Key Usage as the smart card log-on ( Client Authentication (

  • The Online Certificate Status Protocol (OCSP) information for the user’s smart card certificate should be Access Method=On-line Certificate Status Protocol ( in the Authority Information Access.

For more information on AD Connector and smart card authentication requirements, see Requirements in Amazon WorkSpaces Administration Guide. For help troubleshooting Amazon WorkSpaces issues, like logging into WorkSpaces, resetting password, or connecting to WorkSpaces, see Troubleshoot WorkSpaces client issues in Amazon WorkSpaces User Guide.

Certificate revocation checking process

In order to perform smart card authentication, AD Connector must check the revocation status of user certificates using Online Certificate Status Protocol (OCSP). To perform certificate revocation checking, an OCSP responder URL must be internet-accessible. If using a DNS name, an OCSP responder URL must use a top-level domain found in the Internet Assigned Numbers Authority (IANA) Root Zone Database.

AD Connector certificate revocation checking uses the following process:

  • AD Connector must check the Authority Information Access (AIA) extension in the user certificate for an OCSP responder URL, then AD Connector uses the URL to check for revocation.

  • If AD Connector cannot resolve the URL found in the user certificate AIA extension, or find an OCSP responder URL in the user certificate, then AD Connector uses the optional OCSP URL provided during root CA certificate registration.

    If the URL in the user certificate AIA extension resolves but is unresponsive, then user authentication fails.

  • If the OCSP responder URL provided during root CA certificate registration cannot resolve, is unresponsive, or no OCSP responder URL was provided, user authentication fails.

  • The OCSP server must be compliant with RFC 6960. Additionally, the OCSP server must support requests using the GET method for requests that are less than or equal to 255 bytes in total.


AD Connector requires an HTTP URL for the OCSP responder URL.

Other considerations

Before enabling smart card authentication in AD Connector, consider the following items:

  • AD Connector uses certificate-based mutual Transport Layer Security authentication (mutual TLS) to authenticate users to Active Directory using hardware or software-based smart card certificates. Only common access cards (CAC) and personal identity verification (PIV) cards are supported at this time. Other types of hardware or software-based smart cards might work but have not been tested for use with the WorkSpaces Streaming Protocol.

  • Smart card authentication replaces username and password authentication to WorkSpaces.

    If you have other Amazon applications configured on your AD Connector directory with smart card authentication enabled, those applications still present the username and password input screen.

  • Enabling smart card authentication limits the user session length to the maximum lifetime for Kerberos service tickets. You can configure this setting using a Group Policy, and is set to 10 hours by default. For more information on this setting, see Microsoft documentation.

  • The AD Connector service account's supported Kerberos encryption type should match each of the domain controller's supported Kerberos encryption type.