fwTPM command-code masking + vendor-bit return-code fix

[dgarske]

Fixes

• Reject fwTPM command codes with reserved bits set (only the 16-bit index plus the CC_VEND vendor bit are valid) so none can alias a command.
• TPM2_GetCapability(TPM_CAP_COMMANDS) now returns well-formed TPMA_CC values (index + handle attributes + vendor V bit) instead of a bare index.
• WOLFTPM_IS_COMMAND_UNAVAILABLE masks vendor bits from the return code, so a vendor-decorated TPM_RC_COMMAND_CODE (e.g. Nations NS350 0x000b0143) is recognized; fixes bench/wrap/native aborting instead of skipping unsupported commands.

Features

• New WOLFTPM_FWTPM_TCG_TEST build flag gates the optional Vendor_TCG_Test echo command (off by default).

Tests

• fwTPM unit tests for reserved-bit rejection and TPMA_CC reporting; a hardware-free unit test for the vendor-decorated return code.

Fixes #553

[Copilot]

Pull request overview

This PR hardens fwTPM command-code handling and improves compatibility with TPMs that return vendor-decorated error codes, aligning capability reporting and dispatch behavior more closely with the TPM 2.0 expectations.

Changes:

• Enforce fwTPM command-code validity by rejecting any wire command code with reserved bits set (allowing only the 16-bit index plus CC_VEND).
• Make TPM2_GetCapability(TPM_CAP_COMMANDS) emit TPMA_CC entries (including handle attributes and vendor V bit) and update fwTPM tests accordingly.
• Update WOLFTPM_IS_COMMAND_UNAVAILABLE to recognize vendor-decorated TPM_RC_COMMAND_CODE and add unit test coverage; gate the optional vendor echo command behind WOLFTPM_FWTPM_TCG_TEST.

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
wolftpm/tpm2.h	Mask base return-code bits in WOLFTPM_IS_COMMAND_UNAVAILABLE to recognize vendor-decorated TPM_RC_COMMAND_CODE.
src/fwtpm/fwtpm_command.c	Reject reserved-bit command codes, emit TPMA_CC for TPM_CAP_COMMANDS, and gate vendor test command behind WOLFTPM_FWTPM_TCG_TEST.
tests/unit_tests.c	Add unit test ensuring vendor-decorated TPM_RC_COMMAND_CODE is treated as “command unavailable”.
tests/fwtpm_unit_tests.c	Add fwTPM tests for reserved-bit rejection and TPM_CAP_COMMANDS TPMA_CC reporting/paging behavior.
src/fwtpm/README.md	Document reserved-bit enforcement, TPMA_CC reporting, and the optional vendor test command flag.
docs/FWTPM.md	Document WOLFTPM_FWTPM_TCG_TEST and the command-code enforcement / capability behavior.
ChangeLog.md	Add release-note entry describing the fwTPM hardening and vendor-decorated RC handling.

[aidangarske]

Skoll Multi-Scan Review

Modes: review + review-security + bugsOverall recommendation: REQUEST_CHANGES
Findings: 2 total — 2 posted, 0 skipped
2 finding(s) posted as inline comments (see file-level comments below)

Posted findings

• [High] [review+review-security+bugs] Unavailable-command macro aliases negative wolfCrypt errors — wolftpm/tpm2.h:2157-2159
• [High] [review] TPMA_CC rHandle bit is missing for response-handle commands — src/fwtpm/fwtpm_command.c:16057

Review generated by Skoll

[aidangarske]

looks good