In this repository, we have modified the uModbus library and implemeneted encryption of messages that are passed over TCP. Secure keys are generated using Diffie-Helman exchange. These are fed into a KDF to obtain keys for AES encryption
AES mode: CBC-128
Authentication: HMAC (encrypt and MAC)
The secure variation of modbus server is able to serve once per instance. This should be fixable by moving some code chunks around