Harden fwTPM key derivation and command validation

[aidangarske]

F-12728, F-11915, F-12711, F-12737, F-13450, F-13451, F-13462, F-13537

[Copilot]

🟡 Changes recommended

The new RNG parameters are used without defined NULL-handling in hardened ECC paths and the public header prototype changes are API-breaking without an explicit compatibility/versioning plan.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

Pull request overview

This PR hardens fwTPM cryptographic operations and command validation paths, primarily by adding RNG-backed blinding to ECC operations and tightening command behavior around PCR capability reporting, hierarchy selection, and physical presence.

Changes:

• Plumbs WC_RNG* into ECC primary key derivation and ECC shared-point computation to enable RNG-backed timing/blinding hardening where supported.
• Improves safety/robustness in crypto helpers (OOM handling in FwComputePublicName, guarded sensitive marshaling in FwWrapPrivate, and safer RSA CRT cleanup on init failures).
• Tightens command behavior (PCR bank capability output reflects allocated banks; invalid hierarchy selectors return TPM_RC_VALUE vs TPM_RC_HIERARCHY; platform PP latch disabled unless explicitly opted-in).

File summaries

File	Description
wolftpm/fwtpm/fwtpm_crypto.h	Updates public prototypes to accept WC_RNG* for ECC derivation/shared-point routines.
src/fwtpm/fwtpm_crypto.c	Implements RNG-backed ECC hardening and improves error/cleanup handling in several crypto helpers.
src/fwtpm/fwtpm_command.c	Updates PCR capability response generation, refines hierarchy-handle validation, and gates platform PP latch behind an opt-in macro.

Review details

• Files reviewed: 3/3 changed files
• Comments generated: 4
• Review effort level: Lite

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