Implement Intel UPID Support in `rpc-go`

[rsdmike]

🔹 Overview

Intel Unique Platform Identifier (UPID) provides a way to uniquely identify a platform for attestation and verification. We want to integrate UPID support into rpc-go, ensuring that this information is accessible through the amtinfo command.

This will involve:

• Communicating with the Intel UPID driver via HECI (Host Embedded Controller Interface).
• Implementing UPID retrieval logic for both Windows and Linux.
• Exposing the retrieved UPID in amtinfo.

🎯 Task Scope

1️⃣ Windows & Linux HECI Implementation

• Identify and add the correct GUID for the UPID driver in:
  • pkg/heci/windows.go
  • pkg/heci/linux.go
• Implement UPID retrieval by sending the correct MEI commands to the driver.

2️⃣ New UPID Package

• Create a new package (pkg/upid/) to encapsulate UPID logic.
• Implement a UPID retrieval function that abstracts OS-specific logic.
• Ensure it returns the UPID in a structured format.

3️⃣ Integrate UPID into amtinfo Command

• Modify amtinfo to include the UPID in its output.
• Ensure JSON and human-readable formats both display UPID correctly.

4️⃣ Testing & Validation

• Test on real Intel platforms to confirm UPID retrieval works.
• Implement unit tests for UPID logic where possible.
• Add error handling for cases where UPID is not available.

📂 Relevant Files

• pkg/heci/windows.go (HECI driver interaction for Windows)
• pkg/heci/linux.go (HECI driver interaction for Linux)
• pkg/upid/ (new package for UPID retrieval)
• cmd/amtinfo.go (amtinfo command implementation)
• go.mod (if additional dependencies are required)

💻 Technical Details

• Follow the Intel UPID Attestation SDK guide:
  Intel UPID SDK
• Ensure communication via HECI/MEI, using the correct GUIDs for:
  • Windows: Likely uses DeviceIoControl with a relevant GUID.
  • Linux: Likely interacts with /dev/mei or similar.
• Ensure error handling for platforms that do not support UPID.

✅ Acceptance Criteria

• The correct GUIDs are added for Windows/Linux.
• UPID retrieval works on both platforms.
• A new pkg/upid/ package is implemented for UPID management.
• amtinfo displays the UPID in both human-readable and JSON outputs.
• The feature is tested on real Intel hardware.
• A Pull Request (PR) is submitted summarizing the work.

📎 Additional Notes

• If a platform does not support UPID, ensure the code fails gracefully.
• Follow existing patterns in pkg/heci/ to keep the implementation consistent.
• If Intel updates their UPID SDK, check for latest documentation.