photocraft/book/src/security/overview.md

Security overview

PhotoCraft processes complex attacker-controlled files and exposes automation that can act with the user's filesystem permissions. Security is therefore part of parser, engine, I/O, automation, release, and dependency design.

Current posture

Area	Implemented protections	Known limitations / future work
PSD/PSB	Header, channel, decoded-byte, nesting, and pattern limits; malformed/property tests; fuzz targets	Broader hostile corpus, aggregate work budgets, embedded-object coverage
Raster codecs	Default dimension/pixel/allocation limits; decoder-specific budgets; malformed/property tests; fuzz targets	Continuous fuzzing and more format-specific semantic cases
.pcraft	Manifest/blob/total-byte limits; bounded decompression; CRC/hash and version checks; fuzz target	Tighter complexity/entry limits and directory-bundle path-race analysis
Engine commands	Error-return contract, focused bad-parameter tests, adversarial panic_hunt test	Continue eliminating input-derived panic and exhaustion paths
Control TCP	Loopback binding; bearer-token authentication; rooted read/write authority; 1 MiB request lines; 8 MiB replies; 16 active connections; I/O timeouts	No general method capabilities, encryption, client identity, explicit JSON-depth policy, aggregate session-memory/command-duration budgets, or audit trail
MCP	Stdio; typed tools; authenticated and bounded bridge; rooted read/write authority; 256-step batches with aggregate reply budgets; headless preview/output ceilings	No general tool authorization scopes, aggregate session-memory accounting, or command cancellation; transport reply caps do not bound desktop screenshot capture
Dependencies	Cargo lockfile and normal CI build/test/clippy	No cargo-audit or cargo-deny job/configuration confirmed in current tree
Releases	Checksums and platform signing/notarization paths when secrets are configured	Signing can be absent; no SBOM generation confirmed in current tree

The table is a snapshot of the current repository, not a guarantee about deployed artifacts. Verify source and release evidence for high-risk use.

Security priorities

1. Add capability-scoped automation sessions on top of the authenticated transport.
2. Maintain the implemented workspace-handle boundary as file-bearing commands evolve.
3. Extend the preview/reply budgets to JSON complexity, aggregate document/session memory, desktop capture/import/export, and command duration/cancellation.
4. Expand PSD/PSB, codec, and .pcraft fuzzing with regression corpora.
5. Add dependency advisories/license policy checks and release SBOMs.

Start with the Threat model, then use the focused pages for file handling, parsers, fuzzing, and automation.