/zeroize-audit

name: zeroize-audit
description: "Detects missing zeroization of sensitive data in source code and identifies zeroization removed by compiler optimizations, with assembly-level analysis, and control-flow verification. Use for auditing C/C++/Rust code handling secrets, keys, passwords, or other sensitive data."
allowed-tools: Read Grep Glob Bash Write Task AskUserQuestion mcp__serena__activate_project mcp__serena__find_symbol mcp__serena__find_referencing_symbols mcp__serena__get_symbols_overview

zeroize-audit — Claude Skill

When to Use

• Auditing cryptographic implementations (keys, seeds, nonces, secrets)
• Reviewing authentication systems (passwords, tokens, session data)
• Analyzing code that handles PII or sensitive credentials
• Verifying secure cleanup in security-critical codebases
• Investigating memory safety of sensitive data handling

When NOT to Use

• General code review without security focus
• Performance optimization (unless related to secure wiping)
• Refactoring tasks not related to sensitive data
• Code without identifiable secrets or sensitive values

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How to Run

On a request like "audit this crate for secrets left in memory" or "check that this C library actually wipes its keys":

1. **Collect inputs.** Map the request onto the Inputs table below (full schema: `{baseDir}/schemas/input.json`). `path` is required, plus at least one of `compile_db` (C/C++) or `cargo_manifest` (Rust); if neither is given or derivable from the repo, ask the user, because preflight stops the run without one. Leave all other fields at their defaults unless the user says otherwise. 2. **Read the orchestrator prompt, `{baseDir}/prompts/task.md`**, substituting the collected inputs for its `{{placeholder}}` values. You act as the orchestrator it describes: it defines state recovery, the phase loop, early termination, and error handling. Read `{baseDir}/prompts/system.md` alongside it for the shared working-directory layout and the agent error protocol every phase depends on. 3. **Execute its phase loop.** Run Phases 0-7 sequentially. Before each phase, read that phase's workflow file from `{baseDir}/workflows/phase-{N}-{name}.md` and follow its Preconditions, Instructions, State Update, and Error Handling sections. Each workflow specifies which agent to spawn via `Task` and with what parameters. Honor the per-phase skip conditions and the early-termination rules in task.md. 4. **Return the report** (Phase 8, inline): read `{workdir}/report/final-report.md` and return its contents as the skill output.

To resume an interrupted run: if a `workdir` is known from prior context, read `{workdir}/orchestrator-state.json` and continue from its `current_phase` instead of starting at Phase 0 (see the Recovery section of task.md).

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Purpose

Detect missing zeroization of sensitive data in source code and identify zeroization that is removed or weakened by compiler optimizations (e.g., dead-store elimination), with mandatory LLVM IR/asm evidence. Capabilities include:

• Assembly-level analysis for register spills and stack retention
• Data-flow tracking for secret copies
• Heap allocator security warnings
• Semantic IR analysis for loop unrolling and SSA form
• Control-flow graph analysis for path coverage verification
• Runtime validation test generation

Scope

• Read-only against the target codebase (does not modify audited code; writes analysis artifacts to a temporary working directory).
• Produces a structured report (JSON).
• Requires valid build context (`compile_commands.json`) and compilable translation units.
• "Optimized away" findings only allowed with compiler evidence (IR/asm diff).

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Inputs

See `{baseDir}/schemas/input.json` for the full schema. Key fields:

| Field | Required | Default | Description | |---|---|---|---| | `path` | yes | — | Repo root | | `compile_db` | no | `null` | Path to `compile_commands.json` for C/C++ analysis. Required if `cargo_manifest` is not set. | | `cargo_manifest` | no | `null` | Path to `Cargo.toml` for Rust crate analysis. Required if `compile_db` is not set. | | `config` | no | — | YAML defining heuristics and approved wipes | | `opt_levels` | no | `["O0","O1","O2"]` | Optimization levels for IR comparison. O1 is the diagnostic level: if a wipe disappears at O1 it is simple DSE; O2 catches more aggressive eliminations. | | `languages` | no | `["c","cpp","rust"]` | Languages to analyze | | `max_tus` | no | `50` | Limit on translation units processed from compile DB | | `mcp_mode` | no | `prefer` | `off`, `prefer`, or `require` — controls Serena MCP usage | | `mcp_required_for_advanced` | no | `true` | Downgrade `SECRET_COPY`, `MISSING_ON_ERROR_PATH`, and `NOT_DOMINATING_EXITS` to `needs_review` when MCP is unavailable | | `mcp_timeout_ms` | no | `10000` | Timeout budget for MCP semantic queries | | `poc_categories` | no | all 11 exploitable | Finding categories for which to generate PoCs. C/C++ findings: all 11 categories supported. Rust findings: only `MISSING_SOURCE_ZEROIZE`, `SECRET_COPY`, and `PARTIAL_WIPE` are supported; other Rust categories are marked `poc_supported=false`. | | `poc_output_dir` | no | `generated_pocs/` | Output directory for generated PoCs | | `enable_asm` | no | `true` | Enable assembly emission and analysis (Step 8); produces `STACK_RETENTION`, `REGISTER_SPILL`. Auto-disabled if `emit_asm.sh` is missing. | | `enable_semantic_ir` | no | `false` | Enable semantic LLVM IR analysis (Step 9); produces `LOOP_UNROLLED_INCOMPLETE` | | `enable_cfg` | no | `false` | Enable control-flow graph analysis (Step 10); produces `MISSING_ON_ERROR_PATH`, `NOT_DOMINATING_EXITS` | | `enable_runtime_tests` | no | `false` | Enable runtime test harness generation (Step 11) |

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Prerequisites

Before running, verify the following. Each has a defined failure mode.

**C/C++ prerequisites:**

| Prerequisite | Failure mode if missing | |---|---| | `compile_commands.json` at `compile_db` path | Fail fast — do not pr