7.11. Procedure – Verifying certificates with Certificate Authorities


PSM can check the validity of certificates using the certificates and certificate-revocation lists of the certificate authorities that issued the certificates. This can be used for example to verify the certificates of the servers in SSH/RDP connections. To create a list of CA certificates to use during the certificate validation, complete the following steps:


  1. Figure 7.18. Policies > Trusted CA Lists — Creating Trusted CA lists

    Policies > Trusted CA Lists — Creating Trusted CA lists

    Navigate to Policies > Trusted CA Lists and click to create a new list.

  2. Enter a name for the CA list into the topmost field.

  3. Click in the Certificate field, and upload the certificate of the Certificate Authority (CA) that will be used to validate the certificates.

  4. Enter the URL of the Certificate Revocation List of the CA into the CRL field. Certificates appearing on the CRL list will be automatically rejected.


    Note that only .pem format CRLs are accepted. CRLs that are in PKCS7 format (.crl) are not accepted.

  5. To further limit which certificates are accepted, you may use the following options:

    • Strict hostname check: Select this option to accept only certificates when the Common Name of the certificate contains the hostname or the IP address of the host showing the certificate.

    • Use DNS to lookup hostnames: Select this option to use the domain name server set on Basic Settings > Network > Naming to resolve the hostnames and IP addresses for certificate validation. If you have enabled the Strict hostname check option, you probably want to enable this option as well.

    • To restrict the accepted certificates based on the content of the certificate, enter the required value into the appropriate field of the User certificate validation section. For example, to accept only certificates that contain Example Inc. in their Organization Name field, enter Example Inc. in to the Organization Name field. In the Common name, E-mail address, and Alternative e-mail address fields you can use the $username macro to refer to the username used in the connection. This macro makes it possible to check that the user is using his own certificate.

  6. Click .