go-crypt/TODO.md

TODO.md — go-crypt

Dispatched from core/go orchestration. Pick up tasks in order.

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Phase 0: Test Coverage & Hardening

• Expand auth/ tests — Added 8 new tests: concurrent session creation (10 goroutines), session token uniqueness (1000 tokens), challenge expiry boundary, empty password registration, very long username (10K chars), Unicode username/password, air-gapped round-trip, refresh already-expired session. All pass with -race.
• Expand crypt/ tests — Added 12 new tests: wrong passphrase decrypt (ChaCha20+AES), empty plaintext round-trip (ChaCha20+AES), 1MB payload round-trip (ChaCha20+AES), ciphertext-too-short rejection, key derivation determinism (Argon2id+scrypt), HKDF different info strings, HKDF nil salt, checksum of empty file (SHA-256+SHA-512), checksum of non-existent file, checksum consistency with SHA256Sum. Note: large payload test uses 1MB (not 10MB) to keep tests fast.
• Expand trust/ tests — Added 9 new tests: concurrent Register/Get/Remove (10 goroutines, race-safe), Tier 0 rejection, negative tier rejection, token expiry boundary, zero-value token expiry, concurrent List during mutations, empty ScopedRepos behaviour (documented as finding F3), capability not in any list, concurrent Evaluate.
• Security audit — Full audit documented in FINDINGS.md. 4 findings: F1 (LTHN used for passwords, medium), F2 (PGP keys not zeroed, low), F3 (empty ScopedRepos bypasses scope, medium), F4 (go vet clean). No math/rand usage. All nonces use crypto/rand. No secrets in error messages.
• go vet ./... clean — No warnings.
• Benchmark suite — Created crypt/bench_test.go (7 benchmarks: Argon2Derive, ChaCha20 1KB/1MB, AESGCM 1KB/1MB, HMACSHA256 1KB, VerifyHMACSHA256) and trust/bench_test.go (3 benchmarks: PolicyEvaluate 100 agents, RegistryGet, RegistryRegister).

Phase 1: Session Persistence

• Session storage interface — Extracted in-memory session map into SessionStore interface with Get, Set, Delete, DeleteByUser, Cleanup methods. MemorySessionStore wraps the original map+mutex pattern. ErrSessionNotFound sentinel error.
• SQLite session store — SQLiteSessionStore backed by go-store (SQLite KV). Sessions stored as JSON in "sessions" group. Mutex-serialised for SQLite single-writer safety.
• Background cleanup — StartCleanup(ctx, interval) goroutine purges expired sessions periodically. Stops on context cancellation.
• Session migration — Backward-compatible: MemorySessionStore is default, WithSessionStore(store) option for persistent store. All existing tests updated and passing. Commit 1aeabfd.

Phase 2: Key Management

Step 2.1: Password hash migration (addresses Finding F1)

• Migrate Login() from LTHN to Argon2id — Register uses crypt.HashPassword() (Argon2id), writes .hash file. Login detects format: tries .hash (Argon2id) first, falls back to .lthn (LTHN). Successful legacy login transparently re-hashes with Argon2id. Shared verifyPassword() helper handles dual-path logic. 5 tests: RegisterArgon2id_Good, LoginArgon2id_Good, LoginArgon2id_Bad, LegacyLTHNMigration_Good, LegacyLTHNLogin_Bad.

Step 2.2: Key rotation

• RotateKeyPair — Full flow: load private key → decrypt metadata with old password → generate new PGP keypair → re-encrypt metadata → update .pub/.key/.json/.hash → invalidate sessions. 4 tests: RotateKeyPair_Good, RotateKeyPair_Bad (wrong password), RotateKeyPair_Ugly (non-existent user), RotateKeyPair_OldKeyCannotDecrypt_Good.

Step 2.3: Key revocation

• RevokeKey + IsRevoked — Option B chosen: JSON Revocation{UserID, Reason, RevokedAt} record in .rev file. IsRevoked() parses JSON, ignores legacy "REVOCATION_PLACEHOLDER". Login and CreateChallenge reject revoked users. 6 tests including legacy user revocation.

Step 2.4: Hardware key interface (contract only)

• HardwareKey interface — hardware.go: Sign, Decrypt, GetPublicKey, IsAvailable methods. WithHardwareKey() option on Authenticator. Contract-only, no concrete implementations yet. Integration points documented in auth.go.

All Phase 2: commit 301eac1. 55 tests total, all pass with -race.

Phase 3: Trust Policy Extensions

• Approval workflow — Implement the approval flow that NeedsApproval decisions point to. Queue-based: agent requests approval → admin reviews → approve/deny.
• Audit log — Record all policy evaluations (agent, capability, decision, timestamp). Append-only log for compliance.
• Dynamic policies — Load policies from YAML/JSON config. Currently hardcoded in DefaultPolicies().
• Scope wildcards — Support core/* scope patterns in ScopedRepos, not just exact strings.

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Workflow

1. Virgil in core/go writes tasks here after research
2. This repo's dedicated session picks up tasks in phase order
3. Mark [x] when done, note commit hash