Parameter

Description

Enable Transport Layer Security (TLS)

Checkbox for activation of secured communication to destination.

Default: inactive

Certificates path (Private/CA)

Storage path for certificates on the target system. An absolute or relative path can be configured.

The configured path must contain 2 subdirectories CA and PRIVATE.

• The CA directory is the trust list directory and should contain trusted CA certificate files and corresponding certificate revocation lists files in .PEM format.
  
  Filenames for CA certificate files need to be named <subject hash>.0.
  Filenames for certificate revocation lists files need to be named <subject hash>.r0.
• The PRIVATE directory should contain the local certificate plus the key used by the TLS implementation, in a single file in the format .PEM + key.

Example: ./PKI

Private Certificate (.pem)

Filename of the private certificate.

Peer certificate Subject (CN)

Optional Common Name of the peer certificate. When configured, only a connection with a communication partner is established that uses a certificate from a trusted CA with the specified Common Name.

Parameter

Description

Minimal TLS version

Minimum TLS version, used for the secured communication. A TLS version should be selected that is supported by both communication partners. Higher versions offer better security. The internal default maximum TLS version is set at TLS 1.2, except when TLS 1.3 is configured as minimum TLS version.

Selection from a drop-down list:

• (none)
• TLS 1.0
• TLS 1.1
• TLS 1.2
• TLS 1.3

Default: TLS 1.2

TLS 1.0 - 1.2 ciphers (OpenSSL format)

List of supported ciphers, separated with ":"

Default: empty

With the default empty value, all relevant and secure ciphers are supported, depending on the selected TLS version.

Only available if the configured Minimal TLS version is not TLS 1.3.

Example: ECDH-RSA-AES128-SHA256:AES256-SHA256

TLS 1.3 ciphers (OpenSSL format)

Enumeration of supported cipher suites with TLS version 1.3.

Default: empty

With the default empty value, all TLSv1.3 cipher suites are supported.

Example: TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256

Option

Description

OK

Applies settings and closes the dialog.

Cancel

Discards all changes and closes the dialog.

TLS Parameters

IEC 61131-3 Automation platform > Drivers - Fieldbus configuration > MODBUS Master > Fieldbus configuration > Settings in the fieldbus dialogs > Master/port configuration > TLS Parameters