4.20.2.4. Verifying the server certificate

Use the server_certs_verify attribute to control if a server certificate is accepted. The following options are available.

NameValue
RDP_SCV_ACCEPT_ANY Accept any server certificate.
RDP_SCV_ACCEPT_ONCEAccept unknown server certificates only on the first occassion. The IP address-port pair of unknown server certificates is registered, later on that certificate is used to verify connections from that address.
RDP_SCV_ACCEPT_KNOWN Accept only known server certificates. X509 certificates can be configured for each IP address or port pair (like in case of the known_hosts file). For any unknown IP address-port pair the connection is terminated.

Table 4.59.  RDP server certificate verification mode.