Business Connector 4.8.1 TLS 1.3 not selectable

[christian_janson]

Hello everyone,

we are using SAP Business Connector 4.8.1 which should support TLS 1.3. However, we cannot select TLS 1.3 from the respective drop down list:

Our Java version: SAPJVM8_101, tried also OpenJDK 11
Our OS: Ubuntu 24.04 LTS

Further version information:

Does anyone know what can be the root cause for TLS 1.3 not being selectable?

Thank you and best regards

Christian

[MarkusTolksdorf · Accepted solution]

Hello @christian_janson, 

As of today, SAP Business Connector 4.8.1 does not support TLS 1.3. Therefore, you cannot choose this TLS protocol version. 

Best regards,
Markus
P.S.: Ubuntu is not a supported OS release ...

[christian_janson · Accepted solution]

Hello Markus,

thanks for your quick reply.

I'm confused know. According to Ulrich Schmidt TLS 1.3 is possible. Who is right?
https://community.sap.com/t5/technology-q-a/how-to-connect-sap-business-connector-for-web-socket-rfc...

Ulrich Schmidt:
... with the recent updates of the 4.8.1 release in 2020, it is again state-of-the-art in many communication technologies, e.g. TLS 1.3 support for HTTPS, TLS encrypted email communication, or SAP's brand-new WebSocket-RFC protocol

Kind Regards,

Christian

[MarkusTolksdorf · Accepted solution]

Hello Christian, 

actually, both of us ... In general, Business Connector is not supporting TLS 1.3 as it normally uses a dedicated TLS implementation from TU Graz (IAIK library).  However, for the WebSocket RFC implementation of JCo this is not possible and therefore, we have a different behavior in this case. There, the TLS implementation of the JDK will be used. It cannot be configured from the UI what is used in that case, it is a matter of -D parameters for the JVM. Also, the JVM version defines, which TLS versions are available. With the latest SAP JVM implementations, this is possible and is also preferred, if the counterpart (the ABAP system) has enabled TLS 1.3.
If it is an ABAP system in your control, note https://me.sap.com/notes/3318423 will inform you about prerequisites and configuration options

Best regards,
Markus