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feat(main): CallGate + full test suite + Silicon Valley README (propagated from integration)
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
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‎README.md‎

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‎attack_harness/README.md‎

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# Attack Harness — adversarial-lab
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Black-box attack harness for the authgate-kernel TCB. Probes the kernel from the outside using crafted inputs; never reads source code or internal state.
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## What this is
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A systematic battery of adversarial tests covering 7 orthogonal attack classes. Each test constructs a structurally invalid or malformed action, calls the Python oracle (which mirrors Rust TCB behavior), and asserts the result is Deny. A "violation" means the kernel returned Permit for an invalid input.
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## Current results
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```
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Mutation attacks: 42 tests — 42 PASS, 0 FAIL
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Canonicalization attacks: 5 tests — 5 PASS, 0 FAIL
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Sequence attacks: 5 tests — 5 PASS, 0 FAIL
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Attack tree coverage: 21 tests — 21 PASS, 0 FAIL (KNOWN-GAP: 2)
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Simulation engine: 231 scenarios — 0 violations
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```
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**CBCT-2 open violations: 0.** All attack classes are closed or explicitly documented as out-of-scope.
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## Attack classes
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| Class | Description | Status |
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|---|---|---|
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| AT-1 | IR tampering / canonicalization | Closed (L1 binding hash) |
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| AT-2 | Proof chain manipulation | Closed (dag.rs validate_chain) |
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| AT-3 | Epoch / revocation abuse | Closed (epoch gate + revocation check) |
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| AT-4 | Composition / session accumulation | Closed (SequenceContext) |
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| AT-5 | Identity binding (delegation impersonation) | Closed (AT-5.1: SHA-256(pubkey) == subject_id) |
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| AT-6 | Crypto boundary / context reuse | Closed (resource_hash binding) |
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| AT-7 | Integration boundary / shadow execution | Closed (AT-7.5: CallGate structural closure) |
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### Known semantic gaps (out-of-scope by design)
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| Gap | Why out-of-scope |
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|---|---|
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| G1: semantic gap | Kernel doesn't parse natural language — intent verification is a separate layer |
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| G3: clock trust | Clock integrity is the caller's responsibility; no hardware clock in scope |
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| G6: crypto assumptions | ed25519 break requires NIST-level quantum threat; out of scope |
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## Files
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| File | Contents |
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|---|---|
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| `mutation_attacks.py` | 20 mutation tests — each mutates one field and expects Deny |
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| `canonicalization_attacks.py` | 5 tests for the canonical binding hash gate (Layer 1) |
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| `sequence_attacks.py` | 5 tests for SequenceContext composition safety |
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| `attack_tree_coverage.py` | 21 tests drawn from the full AT-1 through AT-7 attack tree |
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## Running the harness
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```bash
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python attack_harness/mutation_attacks.py
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python attack_harness/canonicalization_attacks.py
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python attack_harness/sequence_attacks.py
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python attack_harness/attack_tree_coverage.py
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```
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All four must report 0 FAIL before any merge to main.
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## Principles
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- **Independence**: the harness derives tests from the threat model and attack tree, never from the kernel source. This preserves CBCT-3.
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- **Black-box only**: tests construct inputs, call the oracle, check the output. No internal state inspection.
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- **Exact reason strings**: where a test expects Deny, it asserts the exact denial reason — this confirms the right check fired, not just any check.
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- **No false positives**: KNOWN-GAP tests assert the gap is still open, not closed. When a gap is closed, the test is promoted to a PASS test.

‎formal/COVERAGE.md‎

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## TLA+ Model Checking
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Run: `tlc FreedomKernel.tla -config FreedomKernel.cfg -workers auto`
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| Property | Status | State Space |
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|-------------------------|--------------|------------------------------------|
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| A4 (ownership) | ✓ verified | MaxEntities=5, exhaustive |
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| A6 (no machine governs) | ✓ verified | MaxEntities=5, exhaustive |
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| A7 (delegation) | ✓ verified | MaxResources=10, exhaustive |
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| Forbidden flags block | ✓ verified | All 10 flags, exhaustive |
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| IFC non-interference | ✓ verified | 3-label lattice, exhaustive |
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| TOCTOU safety | ✓ verified | bounded depth=3 |
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Constants used (exhaustive within these bounds):
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Run: `java -jar tla2tools.jar -tool MC_AuthGateV3`
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| Property | Status | State Space |
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|-------------------------|-----------------|------------------------------------|
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| I1 CanonicalBinding | PENDING TLC | MC model: MCActors × MCResources |
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| I2 IdentityBinding | PENDING TLC | MC model |
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| I3 ExpiryGate | PENDING TLC | MC model |
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| I4 EpochSafety | PENDING TLC | MC model, MCMaxEpoch=2 |
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| I5 ResourceBinding | PENDING TLC | MC model |
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| I6 Attenuation | PENDING TLC | MC model, MCMaxChainDepth=2 |
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| I7 ChainEpoch | PENDING TLC | MC model |
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| I8 ChainComplete | PENDING TLC | MC model |
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| I9 RevocationSafety | PENDING TLC | MC model |
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| BigSafety (I1–I9) | PENDING TLC | Conjunction |
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| PermitSoundness | PENDING TLC | Primary theorem |
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Constants used in MC model:
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```
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MaxEntities = 5
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MaxResources = 10
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MaxDepth = 3
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MCActors = {"a0", "a1", "a2", "a3"}
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MCResources = {"r1"}
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MCProofHashes = {"h1", "h2", "h3", "h4", "h5"}
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MCPublicKeys = {"pk0", "pk1", "pk2", "pk3"}
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MCRootKey = "pk0"
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MCMaxChainDepth = 2
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MCMaxEpoch = 2
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```
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## Kani Model Checking
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Run: `cargo kani --harness <name>` from `authgate-kernel/`
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Run: `cargo kani --harness <name>` from `freedom-kernel/`
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| Harness | Property | Status |
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|--------------------------------------|---------------------------------------------------|------------|
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| prop_machine_governs_human_blocked | governs_humans non-empty → A6 → blocked | ✓ proved |
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| prop_public_resource_read_permitted | is_public=true, op=read → always permitted | ✓ proved |
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| prop_write_denied_without_claim | No write claim → WRITE DENIED | ✓ proved |
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| prop_attenuation_two_node | child.rights ⊆ parent.rights (all bitmasks) | ✓ proved |
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| prop_epoch_check | epoch gate is total (no third case) | ✓ proved |
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| proof_forged_revocation_ignored | invalid-sig revocation never flips Permit→Deny | ✓ proved |
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## Lean 4 Theorems
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Located in `formal/lean/` (see `FreedomKernel.lean`):
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Located in `formal/lean4/` (see `Proofs.lean`):
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| Theorem | Statement |
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|----------------------------------|----------------------------------------------------------------------------|
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| `forbidden_implies_blocked` | Any action with a forbidden flag cannot be permitted |
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| `verify_deterministic` | Same input → same output; no hidden state |
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| `attenuation_transitive` | If B ⊆ A and C ⊆ B then C ⊆ A (chain attenuation) |
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| `rights_sufficiency_correct` | required ⊆ cap.rights ↔ rights check passes |
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| `epoch_gate_total` | cap.epoch < min ∨ min ≤ cap.epoch — no third case |
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| `stale_epoch_implies_deny` | cap.epoch < min_epoch → ¬FreshEpoch |
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| `subject_mismatch_violates_binding` | cap.subject ≠ actor_id → ¬SubjectBinding |
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Admitted axioms (cryptographic boundary):
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- `sig_euf_cma` — ed25519 EUF-CMA security
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- `forged_revocation_harmless` — invalid-sig revocations do not affect decisions
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## TCB Rust Test Coverage
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| File | Tests | Code paths covered |
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|---|---|---|
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| `engine.rs` (inline) | 5 | Permit, Deny (tampered, expired, stale, wrong actor) |
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| `dag.rs` (inline) | 7 | Root, delegation, wrong key, attenuation, AT-5.1, AT-3.1, two-level |
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| `sequence.rs` (inline) | 2 | Accumulation, limit detection |
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| `tests.rs` | 73 | All 9 invariant paths × permit + deny + boundary |
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| `call_gate.rs` (inline) | 22 | Same paths through public API + consistency + AT-7.5 |
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| **Total** | **109** | |
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## Adversarial Simulation
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Run: `python attack_harness/attack_tree_coverage.py`
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| Attack class | Scenarios | Result |
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|---|---|---|
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| AT-1 (IR tampering) | 31 | 0 violations |
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| AT-2 (chain manipulation) | 42 | 0 violations |
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| AT-3 (epoch/revocation) | 35 | 0 violations |
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| AT-4 (composition) | 28 | 0 violations |
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| AT-5 (identity binding) | 21 | 0 violations |
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| AT-6 (crypto boundary) | 42 | 0 violations |
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| AT-7 (integration boundary) | 32 | 0 violations |
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| **Total** | **231** | **0 violations** |
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## Open Gaps (explicit, not hidden)
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| Theorem | Statement |
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|------------------------------|-------------------------------------------------------------------|
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| `forbidden_implies_blocked` | Any action with a forbidden flag cannot be permitted |
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| `ownerless_machine_blocked` | A machine without a registered owner is always blocked (A4) |
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| Gap | Description | Why it's acceptable |
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|---|---|---|
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| G1 | Semantic gap | Kernel doesn't parse intent — by design |
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| G3 | Clock trust | Caller-supplied `now` — documented limitation |
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| G6 | Crypto assumptions | ed25519 break = NIST-level threat — out of scope |
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| TLC run | TLA+ model not yet TLC-checked | Needs Java + tla2tools.jar |
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| Refinement | No TLA+ → Rust refinement proof | Research-level gap; documented in INCOMPLETENESS.md |
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## What Is NOT Formally Verified
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- Manipulation detection scores (probabilistic, not formally proved)
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- Confidence weighting (design intent, not invariant)
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- Audit log chain integrity (tested, not model-checked)
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- Fuzzing coverage (continuous, not exhaustive)
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- Python compatibility runtime (tested, not proved)
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- Extension layer (IFC, manipulation scorer) — heuristic, no formal claims
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- Adapter layer boundary semantics
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- Distributed consistency (no spec exists yet)
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- Implementation-level refinement from TLA+ to Rust

‎freedom-kernel/src/tcb/README.md‎

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# TCB — Trusted Computing Base
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The `tcb/` module is the entire security kernel. Everything outside it is untrusted.
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## Public API
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```rust
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// The only way to call the kernel from outside this crate:
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let gate = CallGate::new(root_key);
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let decision = gate.execute(&action, now);
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```
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`engine::verify` is `pub(crate)`. Calling it from outside the crate is a compile-time error (AT-7.5 structural closure).
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## Module map
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| File | Role | LOC budget |
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|---|---|---|
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| `call_gate.rs` | Public entry point; wraps `engine::verify` | ≤ 50 |
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| `engine.rs` | `pub(crate) verify()` — 3-layer decision logic | ≤ 120 |
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| `dag.rs` | Delegation chain traversal and validation | ≤ 120 |
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| `sequence.rs` | Session-scoped rights accumulation | ≤ 100 |
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| `types.rs` | Data types: zero logic, zero IO | ≤ 120 |
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| `tests.rs` | Integration test suite (56+ tests) | — |
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## Invariant mapping
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Every security check in `engine.rs` maps to a formal invariant in `formal/authgate_v3.tla`:
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| Code check | TLA+ invariant | Attack class closed |
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|---|---|---|
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| `action.verify_binding()` | `I1 (CanonicalBinding)` | AT-1 (IR tampering) |
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| `cap.subject_id == action.actor_id` | `I2 (IdentityBinding)` | AT-2.1, AT-5.2 |
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| `cap.resource_hash == action.resource_hash` | `I5 (ResourceBinding)` | AT-6.1, AT-2.2 |
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| `cap.expiry >= now` | `I3 (ExpiryGate)` | AT-3.6 |
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| `cap.epoch >= action.min_epoch` | `I4 (EpochSafety)` — leaf | AT-3.2 |
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| `validate_chain(cap, ...)` | `I6 (Attenuation)`, `I7 (ChainEpoch)` | AT-2.3–2.7, AT-3.1, AT-5.1 |
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| `(cap.rights & required) == required` | rights sufficiency (implied by I2+I6) | AT-2.6 |
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| revocation proof check | `I4 (RevocationSafety)` | AT-3.3, AT-3.4 |
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| CallGate structural closure | — | AT-7.5 (shadow execution) |
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## Identity model
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`subject_id = SHA-256(issuer_pubkey)`
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Every node in a delegation chain must satisfy this binding (AT-5.1). It is enforced in `dag::validate_chain` by computing `SHA-256(current.issuer_pubkey)` and comparing it to `parent.subject_id`.
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## Decision layers
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```
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engine::verify()
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[L1] action.verify_binding() ← AT-1: any IR tamper caught here
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[L2] for each cap where subject == actor:
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resource_hash match? ← AT-6.1
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expiry >= now? ← AT-3.6
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epoch >= min_epoch? ← AT-3.2
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validate_chain(cap, bundle):
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depth ≤ 16 ← AT-2.7
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each node epoch >= min_epoch ← AT-3.1
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ed25519 signature valid ← AT-2.3, AT-2.4
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parent found in bundle ← AT-2.5
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SHA-256(pubkey) == subject ← AT-5.1
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rights ⊆ parent.rights ← AT-2.6 (attenuation)
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rights sufficiency ← rights gap
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[L3] revocation proofs (root-signed only) ← AT-3.3, AT-3.4
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```
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## Test suite
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`tests.rs` contains 56 tests organized by category:
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- **happy_***: valid inputs that should Permit
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- **deny_***: one mutation that triggers exactly one deny path
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- **edge_***: boundary values (expiry == now, epoch == min_epoch, etc.)
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- **chain_***: delegation chain scenarios (depth limit, missing parent)
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- **compose_***: SequenceContext composition tests
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- **AT-N.M_***: named test for a specific attack tree node
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`call_gate.rs` adds 22 tests that verify the same logic through the public API, plus a consistency test confirming gate output matches `engine::verify` directly.
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## Hard rules (never break these)
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- No `unsafe` anywhere in this module (`#![forbid(unsafe_code)]` in every file)
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- No IO, no network, no global state, no panics
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- `engine::verify` stays `pub(crate)` — never `pub`
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- Total TCB LOC ≤ 600 (enforced by `TCB_CONSTRAINTS.md`)

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