neco-vault

Memory-only signing vault built on neco-secp, for Nostr client apps that need to sign events without exposing secret keys.

It's a higher-level layer: secret keys stay inside the vault and aren't returned by any public API — only signed events, ciphertext, and public keys come out.

A Japanese architecture note is available in ARCHITECTURE-ja.md.

Features

• nostr: enable Nostr signing through neco-secp
• nip04: enable NIP-04 encrypt/decrypt through the vault
• nip44: enable NIP-44 encrypt/decrypt through the vault
• nip17: enable gift-wrap DM helpers through the vault
• encrypted: encrypted import/export via AES-256-CBC with scrypt-based key derivation (adds aes, cbc, getrandom, scrypt deps)
• encrypted-legacy-v1: opt-in v1 import compatibility via SHA-256(passphrase)
• security-hardening: enable optional random delay / dummy operation hardening hooks
• wasm: reserved feature for future browser / wasm integration

Design

The vault never returns plaintext secret keys. All operations that need a secret key run inside the vault; only the result (a signed event, ciphertext, or public key) comes out.

Usage

Basic signing

use neco_secp::{SecretKey, UnsignedEvent};
use neco_vault::{Vault, VaultConfig};

let mut vault = Vault::new(VaultConfig::default()).unwrap();
let secret = SecretKey::generate().unwrap();

vault.import_plaintext("main", secret, 100).unwrap();

let signed = vault.sign_event(
    "main",
    UnsignedEvent {
        created_at: 101,
        kind: 1,
        tags: vec![],
        content: "hello".to_string(),
    },
    102,
).unwrap();

assert_eq!(signed.kind, 1);

Active account

The first imported account is automatically set as active. Use sign_event_active to sign without specifying a label.

vault.import_plaintext("alice", secret, 100).unwrap();
// "alice" is now active

vault.set_active("alice").unwrap();
let label = vault.active_label(); // Some("alice")

let signed = vault.sign_event_active(event, 102).unwrap();

Removing the active account sets active to None.

vault.remove("alice").unwrap();
assert_eq!(vault.active_label(), None);

Use labels() to list all stored account labels.

Encrypted import/export (encrypted feature)

Encrypted export uses scrypt-derived keys and AES-256-CBC. Import accepts only the v2 format by default; older SHA-256-derived v1 blobs don't load unless you enable the encrypted-legacy-v1 feature.

let data = vault.export_encrypted("alice", b"passphrase").unwrap();
vault.import_encrypted("bob", b"passphrase", &data, 200).unwrap();

NIP-04 / NIP-44 through the vault

let bob = vault.public_key("bob").unwrap();
let payload = vault.nip44_encrypt_active(&bob, "hello", 101).unwrap();
let text = vault.nip44_decrypt_active(&bob, &payload, 102).unwrap();
assert_eq!(text, "hello");

Security hardening (security-hardening feature)

SecurityConfig lets callers enable constant-time touch points, random delay, and dummy operations for secret-key use paths.

API

License

MIT