# Hashing System Verification Report
**Status:** ✅ COMPLETE - All tools correctly route through cosign infrastructure
**Date:** 2026-02-14
## Summary
All atlas-gate tools have been verified to correctly use the centralized `cosign-hash-provider.js` module for hashing operations. No direct `crypto.createHash()` or `crypto.createHmac()` calls exist in active production code.
## Verification Results
### ✅ Core Infrastructure (Production Code)
- **audit-system.js** - Uses `sha256()` from provider
- **attestation-engine.js** - Uses `sha256()`, `canonicalizeForHash()`, `timingSafeEqual()`, `hmacSha256()`
- **replay-engine.js** - Uses `sha256()`, `canonicalizeForHash()`
- **intent-schema.js** - Uses `sha256()`
- **operator-identity.js** - Uses `sha256()`
- **governance.js** - Uses `hmacSha256()`, `timingSafeEqual()`
- **maturity-report-generator.js** - Uses `sha256()`
- **audit-storage-file.js** - Uses `sha256()`
- **two-step-confirmation.js** - Uses `sha256()`
- **maturity-scoring-engine.js** - Uses `sha256()`
- **remediation-engine.js** - Uses `sha256()`
- **plan-linter.js** - Uses `sha256()`
### ✅ Tools (All Fixed)
- **write_file.js** - Uses `sha256()` for content hashing ✅ Fixed
- **generate-remediation-proposals.js** - Uses `sha256()` for evidence hashing ✅ Fixed
- **verification/verify-audit-log.js** - Uses `sha256()` for chain verification ✅ Fixed
- **verification/verify_security.js** - Unused crypto import removed ✅ Fixed
- **session.js** - Uses `crypto.randomUUID()` (not hashing) - OK
### Acceptable Exceptions
- **Test files** (`tests/`) - Can use direct crypto for backward compatibility
- **Documentation** (markdown, guides) - Only references, not code
- **cosign-hash-provider.js** - Intentionally uses crypto (only module allowed)
## Detailed Code Changes
### Files Modified
```
core/
├─ audit-system.js [Import sha256, remove local function]
├─ attestation-engine.js [Import providers, remove local functions]
├─ replay-engine.js [Import providers, remove local functions]
├─ intent-schema.js [Import sha256, replace crypto call]
├─ operator-identity.js [Import sha256, replace crypto call]
├─ governance.js [Import providers, replace crypto calls]
├─ maturity-report-generator.js [Import sha256, replace crypto call]
├─ audit-storage-file.js [Import sha256, replace crypto call]
├─ two-step-confirmation.js [Import sha256, replace crypto call]
├─ maturity-scoring-engine.js [Import sha256, replace crypto call]
├─ remediation-engine.js [Import sha256, replace crypto call]
├─ plan-linter.js [Import sha256, replace crypto call]
└─ cosign-hash-provider.js [NEW - Centralized provider]
tools/
├─ write_file.js [Import sha256, replace 2 crypto calls]
├─ generate-remediation-proposals.js [Import sha256, replace 2 crypto calls]
└─ verification/
├─ verify-audit-log.js [Import sha256, replace crypto call]
└─ verify_security.js [Remove unused crypto import]
```
## Hashing Architecture
```
┌─────────────────────────────────────────────────────────┐
│ cosign-hash-provider.js (ONLY crypto source) │
├─────────────────────────────────────────────────────────┤
│ • sha256(input) │
│ • canonicalizeForHash(obj) │
│ • signWithCosign(content, keyPair) │
│ • verifyWithCosign(content, signature, keyPair) │
│ • hmacSha256(content, secret) [deprecated] │
│ • timingSafeEqual(a, b) │
└────────┬────────────────────────────────────────────────┘
│
├──→ audit-system.js
├──→ attestation-engine.js
├──→ replay-engine.js
├──→ intent-schema.js
├──→ operator-identity.js
├──→ governance.js
├──→ maturity-report-generator.js
├──→ audit-storage-file.js
├──→ two-step-confirmation.js
├──→ maturity-scoring-engine.js
├──→ remediation-engine.js
├──→ plan-linter.js
│
└──→ tools/
├──→ write_file.js
├──→ generate-remediation-proposals.js
└──→ verification/verify-audit-log.js
```
## Compliance Verification
### Search Results Summary
```bash
grep -r "crypto.createHash\|crypto.createHmac" core/ tools/
# Result: 0 matches (except provider itself)
```
### Direct Crypto Usage
- **Allowed in:** `core/cosign-hash-provider.js` only
- **Forbidden in:** All other active code
- **Acceptable in:** Test files, documentation
## Migration Completeness
| Component | Status | Notes |
|-----------|--------|-------|
| Core infrastructure | ✅ Complete | All using provider |
| Production tools | ✅ Complete | All using provider |
| API consistency | ✅ Complete | Unified interface |
| Backward compatibility | ✅ Maintained | HMAC wrapper preserved |
| Documentation | ✅ Updated | Migration guide created |
| Test files | ⏳ Optional | Can use crypto directly |
## Key Improvements
1. **Single Source of Truth** - All hashing centralized in one module
2. **Determinism** - Canonical JSON ensures consistent results
3. **Cosign Integration** - Ready for ECDSA P-256 signing migration
4. **Audit Trail** - All hash operations logged and traceable
5. **Security** - Timing-safe comparisons for sensitive operations
## Next Steps
1. ✅ Centralize all hashing
2. ✅ Fix tools to use provider
3. ✅ Remove unused imports
4. ⏳ Migrate HMAC signatures to cosign ECDSA P-256
5. ⏳ Update attestation bundle format for cosign signatures
6. ⏳ Deprecate `hmacSha256()` wrapper
## Notes
- All content-addressed operations (plan hashes, audit chain) use SHA256 for determinism
- Sensitive data is redacted before hashing (already implemented)
- Session IDs use `crypto.randomUUID()` which is not affected (correct location)
- No hashing operations are split across multiple modules
