To enable TLS-encryption in an RDP connection policy, you have two options:
Enable Network Level Authentication (NLA, also called CredSSP). To enable NLA in RDP connections, see Network Level Authentication (NLA) with One Identity Safeguard for Privileged Sessions (SPS). Note that Network Level Authentication uses SSL-encryption with self-signed certificates, so you do not have to configure a signing CA.
Complete the following steps to configure TLS-encryption.
Depending on your requirements, one or more of the following might be needed:
To use the same certificate for each session, an X.509 certificate and its private key are required. One Identity Safeguard for Privileged Sessions (SPS) can display this certificate to the peers on the client side. Use your own PKI system to generate these certificates, as they cannot be created on SPS. Note that the Common Name of the certificate must contain the domain name or the IP address of target machine. otherwise the clients might reject the certificate.
To generate certificates on-the-fly for a connection, a signing certificate authority is required. For details on creating a signing CA, see Signing certificates on-the-fly.
One Identity recommends using 2048-bit RSA keys (or stronger).
To configure TLS-encryption
Navigate to RDP Control > Connections and select the connection policy in which you want to enable TLS.
Figure 217: RDP Control > Connections — Enabling TLS-encryption for RDP connections
Set the encryption settings used between the client/server and SPS in the Transport security settings section.
To require encryption, select TLS. When the connection is encrypted, SPS has to show a certificate to the peer.
Select the certificate to show to the peers.
If you want to enable TLS-encryption, but you do not have a certificate that is generated by an external CA, or a signing CA, select Generate self-signed certificate. This option is selected by default.
To use the same certificate for every peer, complete the following steps.
Generate and sign a certificate for SPS in your PKI system, and export the certificate and its private key.
Select Use the same certificate for each connection.
Select Private key for host certificate, click and upload the private key.
Select X.509 host certificate, click and upload the certificate.
If you want to use your own Signing CA, complete the following steps.
Create a certificate authority that will be used to sign the certificates that SPS shows to the peer. For details, see Signing certificates on-the-fly.
Select Generate certificate on-the-fly.
In the Signing CA field, select the certificate authority to use.
NOTE: Import the certificate of the signing Certificate Authority to your clients. Otherwise, the client applications will display a warning because of the unknown Certificate Authority.
To disable TLS-encryption for RDP connections completely, select Legacy RDP Security Layer (also known as: Standard RDP Security). You might want to do this if you were using legacy RDP encryption, and you are experiencing compatibility issues. For example, you might experience compatibility issue when you attempt to connect to a very old Windows machine (for example, Windows Server 2003 or older).
(Optional) Even if you choose TLS-encryption , you have the option to choose using legacy RDP encryption as well. If you experience compatibility issues (for example, when you attempt to connect to a very old Windows machine, such as Windows Server 2003 or older) and want to allow using legacy RDP encryption if TLS-encryption is not possible, select Allow fallback to legacy RDP Security Layer (also known as: Standard RDP Security).
|Caution: Security Hazard!
Selecting the Legacy RDP Security Layer or the Allow fallback to legacy RDP Security Layer options can significantly reduce the strength of the encryption used.
Selecting these options is only recommended if you cannot overcome compatibility issues in any other way.
To avoid security hazard, we recommend using TLS encryption.
The encryption settings are applied to the connection policy.