# Theus v3.0.2 Security & Code Audit Report

**Date:** 2026-01-26
**Auditor:** Antigravity (Agentic AI)
**Version:** v3.0.2 (Commit: Current)

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## 1. Executive Summary

Theus v3.0.2 introduces key security architecture changes (`ContextGuard` with Shadow Copies, `SupervisorProxy` aliases) to address previous Context Leak vulnerabilities. This audit confirms that the **Integrity of the Global State is SECURE**. The fix prevents unauthorized side-channel mutations. Additionally, the new **Smart CAS (Compare-And-Swap)** and **Conflict Manager** systems provide robust concurrency control.

**Overall Status:** ✅ **PASSED** (Secure & Production Ready for Controlled Environments)

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## 2. Detailed Findings

### 2.1. Integrity & State Mutability (Critical)

*   **Vulnerability Check (Context Leak):** The previous vulnerability where `ctx.domain` allowed direct raw state mutation is **FIXED**.
    *   `src/structures.rs`: Replaced raw dict accessors with `SupervisorProxy` aliases.
    *   `src/guards.rs`: Implemented `get_shadow()` (Deep Copy) before upgrading a Proxy to Write Mode.
    *   **Verification:** Manual verification via `verify_domain_ctx_leak.py` confirms that `ctx.global_ctx` returns a safe proxy.

*   **Contract Enforcement:**
    *   The `TheusEngine` enforces POP Contracts (Inputs/Outputs).
    *   **Bypass Attempt:** A Proof-of-Concept (`poc_contract_bypass.py`) confirmed that **Direct Mutation** of `ctx` (e.g., `ctx.domain.secret = 666`) is effectively a No-Op. The changes are made to a Shadow Copy but are **discarded** because the process contract requires explicit returns (`StateUpdate` or Dict).
    *   **Implication:** Side-Effects are impossible unless explicitly declared and returned. This creates a functional "Pit of Success" for security.

### 2.2. Concurrency & Transaction Safety

*   **Optimistic Control (OCC):**
    *   `src/engine.rs`: `compare_and_swap` implements fine-grained conflict detection.
    *   **Key-Level Versioning:** The system correctly checks `key_last_modified` map to allow non-overlapping updates from different transactions to merge safely.
    *   **Borrow Safety:** The implementation correctly drops Rust RefCell borrows (`drop(current_state)`) before re-entering Python code, preventing potential Panics/Deadlocks.

*   **Conflict Resolution:**
    *   `src/conflict.rs`: Implements **Exponential Backoff** with Jitter and a **VIP Priority** mechanism.
    *   Logic allows a process failing >5 times to acquire a "VIP Ticket", blocking others to ensure progress. This prevents livelocks under high contention.

### 2.3. Shared Memory Safety

*   **Zero-Copy Architecture:**
    *   `src/shm.rs`: Defines strict `BufferDescriptor` for metadata exchange.
    *   `theus/context.py`: `SafeSharedMemory` wrapper forbids `unlink()` calls by consumers (Borrowers), preventing accidental destruction of shared segments.
    *   **Zombie Cleanup:** `src/shm_registry.rs` tracks PIDs and correctly unlinks segments from dead processes.
    *   *Note:* The registry file (`.theus_memory_registry.jsonl`) uses simple file appending. In ultra-high concurrency multi-user environments, a proper DB or File Lock is recommended.

### 2.4. Code Quality & Linting

*   **Standards:** The codebase passes `ruff` (Python) and `cargo clippy` (Rust) with **Zero Warnings**.
*   **Unsafe Code:**
    *   Used sparingly in `src/supervisor.rs` and `src/nano.rs` (`unsafe impl Send/Sync for SafePyRef`). This is a standard PyO3 pattern for transferring Python object references across thread boundaries protected by the GIL.
    *   No dangerous raw pointer arithmetic found in core logic.

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## 3. Recommendations

1.  **Direct Mutation Deprecation:** Since `ctx.domain.x = 1` is now a No-Op (safe but confusing), we should explicitly document that **Functional Returns** are the ONLY way to persist state changes.
2.  **Production Logging:** Remove or gate `println!("DEBUG: ...")` calls in `src/guards.rs` for Release builds to reduce I/O overhead.
3.  **Registry Hardening:** For multi-tenant deployments, replace the JSONL registry with a SQLite or Redis solution to avoid file contention.

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**Signed,**
*Antigravity Audit Bot*
