@railgun-reloaded/cryptography

Cryptographic primitives shared across the RAILGUN reloaded packages.

This package wraps the underlying WASM/JS libraries (circomlibjs, poseidon-lite, @noble/hashes) and exposes a small, validated surface for use by wallet-node, merkletree-manager, and other consumers in the RAILGUN SDK.

Installation

npm install @railgun-reloaded/cryptography

What's included

Primitive	Symbols	Notes
Poseidon (circomlibjs, BabyJubJub field)	poseidon, poseidonBuild, initCircomlib	Used for note hashes and key derivation. Inputs are 32-byte field elements.
Poseidon (poseidon-lite, n-input variants)	poseidonFunc	Convenience wrapper for poseidon1..poseidon14. Sync. Accepts bigint, number, string, or Uint8Array inputs.
EDDSA over BabyJubJub	eddsa, initializeEddsa	Sign and verify with Poseidon hashing.
AES-256-GCM / AES-256-CTR	AES, Ciphertext, CiphertextCTR	Authenticated and streaming symmetric encryption.
Keccak-256	keccak256	Thin wrapper over @noble/hashes/sha3.

What's not here: BIP32/BIP39 mnemonic derivation, SLIP-10 paths, secp256k1 signing — those live in @railgun-reloaded/wallet-node since they are wallet-shaped concerns rather than primitives.

Initialization

Poseidon and EDDSA wrap WASM modules and must be initialized before use:

import { initCircomlib, initializeEddsa } from '@railgun-reloaded/cryptography'

await initCircomlib('wasm')   // populates the wasm-backed poseidon
await initCircomlib('pure')   // optional fallback in pure JS
await initializeEddsa()       // ready to sign/verify

poseidon prefers wasm and falls back to pure automatically; calling it without any initCircomlib call throws.

poseidonFunc, keccak256, and AES are synchronous and require no initialization.

Usage

import { AES, eddsa, keccak256, poseidon, poseidonFunc } from '@railgun-reloaded/cryptography'

// Poseidon over field elements (Uint8Array, ≤32 bytes each)
const noteHash = poseidon([npk, tokenHash, valueBytes])

// poseidon-lite convenience wrapper (sync, accepts mixed input types)
const h = poseidonFunc([1n, 2n, 3n])              // Uint8Array
const hAsBigInt = poseidonFunc([1n, 2n, 3n], true) // bigint

// EDDSA roundtrip (after initializeEddsa())
const pubKey = eddsa.privateKeyToPublicKey(privateKey)
const [r8x, r8y, s] = eddsa.signPoseidon(privateKey, message)

// AES-256-GCM (authenticated)
const ct = AES.encryptGCM([plaintext], key)
const [recovered] = AES.decryptGCM(ct, key)

// Keccak-256
const digest = keccak256(input)

Scripts

npm run build     # tsc --build
npm run lint      # eslint
npm run lint:fix  # eslint --fix
npm test          # build + brittle test suite

License

MIT