Forensic Test Plan & Verification Strategy

Continuous Integration Status: 190+ Automated Tests Passing (100% Green)
Frameworks: pytest, pytest-cov, unittest, Headless Browser / Node Test Runners
Primary Orchestrator: bash scripts/build_all.sh

1. Quality Assurance Strategy & Test Pyramid

In forensic data sanitization and legal evidence handling, software defects are catastrophic: - An undetected flaw in a wiping routine could leave classified intelligence readable on decommissioned hardware. - A bug in a carving algorithm could miss crucial evidence in a criminal investigation or calculate inaccurate hashes that compromise chain of custody. - A signature validation defect could permit an adversary to present fraudulent wipe certificates in court.

To mitigate these risks, s0 employs a rigorous five-layer test pyramid:

graph TD
    subgraph Level5 ["Level 5: Cross-Language Verification"]
        PORTAL[Node.js / WebCrypto Parity with Python Canonical JSON]
    end

    subgraph Level4 ["Level 4: End-to-End Forensic Demonstrations"]
        E2E_WIPE[demo_e2e.sh: Sparse Disk + Planted Markers -> 0 Hits]
        E2E_NTFS[demo_e2e_ntfs.sh: NTFS $MFT Carving & Runlist Reassembly]
    end

    subgraph Level3 ["Level 3: Subsystem Integration"]
        GUI_TESTS[FastAPI Headless Test Client for All 4 Module Endpoints]
        AUDIT_TESTS[Ledger Hash-Chaining & Simulated Block Row Tampering]
    end

    subgraph Level2 ["Level 2: Engine & Driver Probes"]
        SAFETY_TESTS[Root Mount Safety Gates & Device Refusal Checks]
        CARVER_TESTS[Shannon Entropy, Magic Signatures & Cluster Heuristics]
        ERASER_TESTS[Cluster In-Place Overwrites, Timestamps & ADS Scrubbing]
    end

    subgraph Level1 ["Level 1: Cryptographic Foundation"]
        TAMPER_MATRIX[Full Tree Mutation Matrix: Every Leaf Node Tampered]
        CANONICAL_TESTS[Golden Vector Test Suite canonical_vectors.json]
        ED25519_TESTS[RFC 8032 Keygen, Signing & Signature Roundtrips]
    end

    Level1 --> Level2 --> Level3 --> Level4 --> Level5

2. Test Suites Reference

Test File	Subsystem	Invariants & Test Objectives
`core/tests/test_canonical.py`	Cryptographic Core	Asserts that `s0_core.canonical` generates byte-exact output matching RFC-inspired golden test vectors in `canonical_vectors.json`. Asserts rejection of floating-point numbers.
`core/tests/test_crypto.py`	Cryptographic Core	Tests Ed25519 keypair generation, PEM serialization/deserialization, SHA-256 fingerprint derivation, and signature validation roundtrips.
`core/tests/test_tamper.py`	Cryptographic Core	The Tamper Matrix: Recursively traverses every key and value in a valid certificate, mutates each character individually, and asserts that `verify_certificate()` rejects 100% of mutations.
`core/tests/test_pdf.py`	Certificate Rendering	Validates ReportLab PDF document compilation, table geometry, font fallbacks, and optical QR code matrix rendering.
`linux/cli/tests/test_selection_safety.py`	Module 1: Drive Eraser	Asserts that the safety engine refuses to wipe root (`/`), `/boot`, mounted partitions, or devices with unreadable capacity unless `--force` is supplied.
`linux/cli/tests/test_overwrite.py`	Module 1: Drive Eraser	Validates single-pass zero and multi-pass CSPRNG random block streaming, block boundary alignment, and `fsync()` flushing.
`linux/cli/tests/test_firmware_probes.py`	Module 1: Drive Eraser	Unit tests parser routines for `hdparm -I`, `nvme id-ctrl`, HPA/DCO boundary queries, and ATA Security status flags.
`linux/cli/tests/test_e2e_demo.py`	Module 1: Drive Eraser	Programmatically builds a loopback disk image, plants confidential marker tokens, executes sanitization, performs 64-block sampling, and asserts zero marker hits.
`linux/cli/tests/test_file_eraser.py`	Module 2: File Eraser	Tests cluster overwriting, inode timestamp zeroing (`1970-01-01T00:00:00Z`), directory entry scrambling, recursive directory unlinking, and batch certificate generation.
`linux/cli/tests/test_carver.py`	Module 3: File Carver	Tests 3-point Shannon entropy calculations, confidence scoring math, sliding-window header/footer carving, and recovery manifest generation.
`linux/cli/tests/test_ntfs_carver.py`	Module 3: File Carver	Mounts synthetic NTFS images with deleted files; validates $MFT resident extraction and multi-fragment non-resident runlist reassembly.
`linux/cli/tests/test_audit.py`	Module 4: Audit Ledger	Tests genesis block initialization, append-only block insertion, SHA-256 hash chaining, and asserts that modifying a database row breaks verification.
`web/tests/test_gui.py`	Web Dashboard	Uses FastAPI's `TestClient` to execute end-to-end API calls across all four tabs without launching a live browser.
`verification-portal/tests/test_portal.py`	Verification Portal	Tests that the pure JavaScript verifier (`verify.js`) produces identical verification decisions to the Python reference engine across valid and tampered certificates.
`windows/cli/tests/`	Windows Subsystem	Validates Win32 API interactions, Alternate Data Stream (`:Zone.Identifier`) enumeration, and ReFS CoW detection.
`macos/cli/tests/`	macOS Subsystem	Tests Apple Darwin `fcntl(F_FULLFSYNC)` flushes, `xattr -c` quarantine removal, and APFS snapshot warnings.

3. Running Test Suites

Master Build & Test Orchestration

To execute the complete QA verification pipeline:

# Execute master build, venv setup, and comprehensive test suite
bash scripts/build_all.sh

Targeted Pytest Execution

# Run all automated tests with verbose output
.venv/bin/pytest core/tests linux/cli/tests web/tests windows/cli/tests macos/cli/tests verification-portal/tests -v

# Run only cryptographic core tests
.venv/bin/pytest core/tests -v

# Run only file carver tests
.venv/bin/pytest linux/cli/tests/test_carver.py linux/cli/tests/test_ntfs_carver.py -v

Forensic End-to-End Demonstrations

To execute real-world disk sanitization and evidence extraction scenarios:

# 1. Drive Eraser End-to-End Demo (Plants markers, wipes, verifies 0 hits)
S0_DEMO_SIZE_MIB=32 bash linux/cli/demo_e2e.sh

# 2. NTFS Structure Carving Demo (Builds NTFS image, deletes files, carves via $MFT)
bash linux/cli/demo_e2e_ntfs.sh