# CLAUDE.md — relicario

## What is this

relicario is a git-backed, self-hostable password manager with a Rust core. Two-factor vault decryption: passphrase + a reference JPEG carrying a 256-bit secret embedded via DCT steganography. The server only ever sees opaque ciphertext.

## Build and test

```bash
cargo build                                        # build everything
cargo test                                          # run all tests (unit + integration)
cargo test -p relicario-core                        # core library tests only
cargo test -p relicario-cli --test basic_flows     # CLI integration tests
cargo build -p relicario-wasm --target wasm32-unknown-unknown   # WASM target
cargo run -p relicario-cli -- --help               # CLI help
cargo run -p relicario-cli -- generate --length 32 # quick smoke test
```

## Project structure

```
crates/
├── relicario-core/            # Platform-agnostic library (no filesystem, no git, no network)
│   ├── src/
│   │   ├── lib.rs          # Re-exports public API
│   │   ├── error.rs        # RelicarioError enum (thiserror)
│   │   ├── crypto.rs       # Argon2id KDF (length-prefixed, Zeroizing) + XChaCha20-Poly1305
│   │   ├── ids.rs          # ItemId, FieldId, content-addressed AttachmentId
│   │   ├── time.rs         # now_unix, MonthYear
│   │   ├── item_types/     # per-type cores + ItemType/ItemCore enums
│   │   ├── item.rs         # Item envelope, Field, FieldKind, FieldValue, Section
│   │   ├── attachment.rs   # AttachmentRef, EncryptedAttachment, encrypt/decrypt helpers
│   │   ├── manifest.rs     # Browse-without-decrypt index (schema_version 2)
│   │   ├── settings.rs     # VaultSettings: retention, generator defaults, caps
│   │   ├── generators.rs   # CSPRNG password + BIP39 + zxcvbn gate
│   │   ├── vault.rs        # JSON ↔ AEAD wrappers for Item/Manifest/VaultSettings
│   │   └── imgsecret.rs    # DCT steganography (MAX_DIMENSION cap)
│   └── tests/              # integration.rs, attachments.rs, generators.rs, format_v2.rs, field_history.rs
├── relicario-cli/             # `relicario` binary
│   ├── src/main.rs         # clap surface + command handlers
│   ├── src/helpers.rs      # vault_dir, git_command, iso8601
│   ├── src/session.rs      # UnlockedVault (master key in Zeroizing)
│   └── tests/              # basic_flows, edit_and_history, attachments, settings, vault_detection
└── relicario-wasm/            # WASM bindings for the extension
    ├── src/lib.rs          # #[wasm_bindgen] surface
    └── src/session.rs      # opaque SessionHandle → Zeroizing<[u8;32]>
```

## Key design decisions

- **relicario-core is bytes-in/bytes-out.** No filesystem, no network, no git operations. Makes it portable to WASM, Android, iOS.
- **XChaCha20-Poly1305** over AES-GCM — 192-bit nonce eliminates collision risk, fast in WASM/ARM without AES-NI.
- **Single master_key** (no per-entry subkeys) — simpler, sufficient for family vault sizes.
- **imgsecret uses central-embed DCT** — embeds only in the middle 70% of the image (15% crumple zone for crop tolerance), with majority voting across 5-50 redundant copies.
- **QUANT_STEP = 50.0** — higher than typical (25) to survive JPEG recompression down to Q85.
- **Device ed25519 keys are separate from the KDF.** Revoking a device doesn't require rotating the passphrase or reference image.

## Crypto pipeline

```
passphrase (UTF-8 bytes) || image_secret (32 bytes from reference JPEG)
  → Argon2id(salt=vault_salt, m=64MiB, t=3, p=4)
  → master_key (32 bytes)
  → XChaCha20-Poly1305(nonce=random 24 bytes)
  → encrypted Item/Manifest/VaultSettings
```

## Conventions

- Tests use fast Argon2id params (m=256, t=1, p=1) so they don't take forever.
- Test JPEGs are generated synthetically via `make_test_jpeg()` — no binary test fixtures.
- Item IDs are random 8-char hex strings.
- Git history is preserved as an audit log — no squashing.
- The CLI shells out to `git` for sync — no libgit2/gitoxide dependency.

## Remote

Source code: `ssh://git@git.adlee.work:2222/alee/relicario.git`

## Design spec

Full threat model, entropy analysis, and architecture: `docs/superpowers/specs/2026-04-11-relicario-design.md`

## Roadmap

Next: WASM build + Chrome MV3 browser extension (Plan 2). Then mobile (Rust core compiles to ARM).