Possible Non-Compliance with OCPP Specification Regarding Unique Message IDs

[Tano-Coppoletta]

Checklist

• [ ] I checked other issues already, but found no answer/solution
• [ ] I checked the documentation and wiki, but found no answer/solution
• [ ] I am running the latest version and the issue still occurs
• [x] I am sure that this issue is about SteVe (and not about the charging station software or something unrelated to SteVe)

Specifications

SteVe Version     : 3.6.0
Operating system  : Ubuntu 22.04.1
JDK               : openjdk version "11.0.20.1"
Database          : version 1.0.3

Issue Description

According to the OCPP specification, each CALL message's ID must be unique and not reused within the same WebSocket connection. However, during testing, it was possible to send multiple messages using the same message ID without any rejection by the server.

Steps to Reproduce

1. Establish a WebSocket connection to the Steve OCPP server.
2. Send multiple OCPP CALL messages using the same message ID.
3. Observe that the server accepts and processes these messages without enforcing the uniqueness of message IDs.

Expected Behavior

The server should enforce the OCPP specification by checking the uniqueness of the message ID for each CALL message and reject any messages with a duplicate message ID.

Actual Behavior

The server processes messages with duplicate message IDs, which is against the OCPP specification and could lead to message tracking issues or misinterpretation of message responses.

Potential Impact

This behavior could cause confusion in message correlation, response handling, and could potentially impact the transactional integrity of the communication between charging stations and the central system.

Suggested Solution

Implement a check on the server to ensure message IDs are unique for each CALL message on the same WebSocket connection and reject any messages that violate this rule.

Compliance Reference

Please refer to section 4.1.4 of the OCPP JSON 1.6 documentation that states the requirement for message ID uniqueness.