tpm-top

tpm-top is a Go-based terminal utility like top for TPM. It displays information about the TPM to which it is connected.

Views

PCRs

In this view, tpm-top displays all the PCR values that can fit into the window. It live-updates every 1 second, reflecting the current state of all the PCRs.

NOTE: The Microsoft TPM Simulator comes by default with SHA1 and SHA2-256 banks enable. Use tpm-tool pcr-banks (below) and reboot the simulator to pick just one PCR bank.

Supported TPM types

• TCP simulator (like the Microsoft reference TPM 2.0)

To aid development and demonstration of tpm-top, some additional tools are included in this repository:

• tpm-tool
  • A tool that can send a few sample commands to a running TPM.
• sim-start
  • A tool that can (re)start a running TCP simulator.

Building

• tpm-top (like all other tools in this repo) is built using go build, e.g., from the root of the repository, run:

go build cmd/tpm-top

tpm-tool Commands

tpm-tool supports the following commands:

• startup
  • Starts up the TPM.
• shutdown
  • Shuts down the TPM.
• pcr-banks <alg1> <alg2>...
  • Enables the PCR banks for the given algorithm(s).
  • NOTE: The change will not take effect until you power cycle the TPM. You can do this with:
    • tpm-tool shutdown
    • sim-start
    • tpm-tool startup
• extend <index> <file>
  • Extends the contents of <file> into PCR <index> in all active PCR banks.
  • <file> must be 1KB or smaller.
• explain
  • Formats a TPM 2.0 error code and prints out the explanation.

Starting the simulator

tpm-top currently only connects to a running TCP simulator, even if there is a perfectly good local TPM on the system.

• Clone the Microsoft reference implementation.
• Build the simulator using the instructions from that repository.
• Start the simulator from the command-line.
• Use sim-start and tpm-tool startup to power-on the simulated TPM.