Control of access to the PLC source code
From version Build 4024, TwinCAT 3 offers the option to encrypt PLC source code and to control access to the PLC source code via rights management. The central element is a user database (User DB), which is created with the inclusion of the OEM certificate (as the verification basis).
Note: The OEM certificate is only required to create the user database, not to use or modify it.
Prerequisite for using this function: Issue of a TwinCAT OEM certificate
System requirements
- TwinCAT 3 OEM certificate TC0007 (Crypto version 1 or 2)
- Operating system: at least Windows 10
- TwinCAT version: at least TwinCAT 3.1 Build 4024
 | Reliable protection only when using the latest TwinCAT 3 version For reliable protection (e.g. secure encryption), always use the latest TwinCAT 3 version. This provides the maximum security. Use at least TwinCAT 3.1 Build 4024.x. |
General notes
- Observe the general information regarding OEM certificates.
- The OEM certificate is only required once to create the User DB.
- Changes to the User DB only need to be signed by the administrator of the User DB (without using the OEM certificate).
- It is essential for the administrator of the User DB to have a strong password. Otherwise the User DB is easy to attack.
- The validity of the User DB is independent of the validity period of the OEM certificate. The User DB therefore remains valid even after the expiry of the validity period of the OEM certificate and can also be modified afterwards.
- Comments on the later extension of the certificate (after 2 years) can be found here Extending an OEM certificate.
- Important: store the password of the OEM certificate and the administrator of the User DB in a secure place. Beckhoff cannot restore the passwords if they are lost!
- The OEM certificate is not required on the target systems and should not be stored there for security reasons!
Procedure
The following procedure describes the simplest case:
- There is one user ("Admin") who has full access to the project
- All others ("Guest") are not allowed to view or modify the project.
- The administrator authenticates himself via a (secure!) password
Links to documentation
- Requesting (ordering) an OEM certificate
- Installing the OEM certificate
- Creating a user database
For the simplest standard case, you only need to define the administrator's name and his password and execute no further settings (e.g. no creation of additional users) in the User DB. - Linking the user database to a project
- Setting the encryption of the project file
- Setting access rights for PLC project root