[drk-ram]

What this changes

Closes #644.

Hardens offline Intel TDX collateral appraisal in prototype/tdx_collateral.py:

• Rejects NaN, Infinity, -Infinity, and overflowed float literals (1e309, -1e309) in _json via parse_constant and parse_float.
• Rejects trailing continuation bytes (value[-1] & 0x80 != 0) and non-minimal leading 0x80 subidentifier bytes in _oid, and rejects duplicate OIDs in _pck_extension.
• Enforces exact int types (type(...) is int) on QCNL cache expiration hours (pck_cache_expire_hours, verify_collateral_cache_expire_hours), collateral snapshot version and tee_type, tcbInfo version and tcbType, qeIdentity version and isvprodid, and tcbEvaluationDataNumber.
• Validates that advisoryIDs (when present) is a list of non-empty str items before sorting.

Validation commands and results:

• PYTHONPATH=src python -m pytest tests/test_tdx_collateral.py -q -> passed (36 passed, 51 skipped)
• python -m ruff check prototype/tdx_collateral.py tests/test_tdx_collateral.py -> passed (All checks passed!)
• python tools/check_dashes.py -> passed (no dashes outside examples/, spec/trace-v0.1.md)
• PYTHONPATH=src python tools/review_bar.py --base origin/main --head HEAD -> passed (23 changed test cases fail on behaviour at origin/main)

Type of change

• Editorial (typo, link fix, clarification: no normative effect)
• Non-breaking spec change (new optional field, new platform profile, informative addition)
• Breaking spec change (requires 14-day comment period and Project Lead sign-off)
• Schema change
• Example addition

Spec section

prototype/tdx_collateral.py (experimental Intel TDX QVL collateral appraisal prototype; no normative change to spec/trace-v0.2.md)

Tests for a fix

• parse_constant=_no_constants and parse_float=_finite_float in _json: tests/test_tdx_collateral.py::test_json_rejects_nan_infinity_and_float_overflow
• Trailing continuation byte and leading 0x80 subidentifier byte checks in _oid: tests/test_tdx_collateral.py::test_oid_rejects_trailing_continuation_and_leading_zero_subidentifier
• Duplicate outer/inner OID checks in _pck_extension: tests/test_tdx_collateral.py::test_pck_extension_rejects_duplicate_outer_and_inner_oids
• Exact int checks on pck_cache_expire_hours and verify_collateral_cache_expire_hours in _check_qcnl: tests/test_tdx_collateral.py::test_check_qcnl_rejects_boolean_and_float_cache_expire_hours
• Exact int checks on snapshot["version"], snapshot["tee_type"], tcb_info["version"], tcb_info["tcbType"], qe_identity["version"], qe_identity["isvprodid"], and list[str] validation on advisoryIDs in appraise_collateral: tests/test_tdx_collateral.py::test_appraise_collateral_rejects_non_int_fields_and_invalid_advisory_ids

Changelog entry

• Fixed (prototype(tdx_collateral): reject non-finite JSON, non-minimal/duplicate PCK OIDs, boolean integer fields, and non-list advisoryIDs #644). prototype.tdx_collateral now rejects non-finite JSON constants and overflowed floats in _json, incomplete or non-minimal DER OIDs and duplicate OIDs in _pck_extension, boolean/float values on integer collateral/QCNL fields, and non-list or non-string advisoryIDs.

Checklist

• DCO sign-off on all commits (git commit -s)
• Breaking changes marked with <!-- CHANGED: #NNN: description --> in spec text
• Backward compatibility statement included (for breaking changes)

[github-actions]

🟡 Contributor Check: MEDIUM

Check	Result
Profile	MEDIUM
Credential	LOW
Overall	MEDIUM

Automated check by AgenTrust Contributor Check.

[rajnisht7]

Batch response for this cluster is here: #653 (comment)