wallet-core: Add basic setup with keys generation

Resolves #2116

wallet-core/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "wallet-core"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+dusk-bytes = "0.1"
+bytecheck = { version = "0.6", default-features = false }
+execution-core = { version = "0.1", path = "../execution-core/" }
+zeroize = { version = "1", default-features = false, features = ["derive"] }
+rand_chacha = { version = "0.3", default-features = false }
+sha2 = { version = "0.10", default-features = false }
+
+[dev-dependencies]
+
+[features]

wallet-core/Makefile

@@ -0,0 +1,29 @@
+TARGET_DIR:="../../target/dusk"
+
+all: ## Build the ABI
+	cargo build
+
+help: ## Display this help screen
+	@grep -h -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-15s\033[0m %s\n", $$1, $$2}'
+
+test:
+	cargo test --release
+
+
+wasm: ## Build the WASM files
+	@RUSTFLAGS="$(RUSTFLAGS) --remap-path-prefix $(HOME)= -C link-args=-zstack-size=65536" \
+	CARGO_TARGET_DIR=$(TARGET_DIR) \
+	cargo +dusk build \
+		--release \
+		--color=always \
+		-Z build-std=core,alloc \
+		--target wasm64-unknown-unknown
+
+clippy: ## Run clippy
+	@cargo clippy --release -- -D warnings
+	@cargo clippy --no-default-features --release -- -D warnings
+
+doc: ## Run doc gen
+	@cargo doc --release
+
+.PHONY: all help test

wallet-core/src/keys.rs

@@ -0,0 +1,91 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//
+// Copyright (c) DUSK NETWORK. All rights reserved.
+
+//! Utilities to derive keys from the seed.
+
+use rand_chacha::{rand_core::SeedableRng, ChaCha12Rng};
+use sha2::{Digest, Sha256};
+
+use execution_core::{
+    signatures::bls::SecretKey as BlsSecretKey,
+    transfer::phoenix::{
+        PublicKey as PhoenixPublicKey, SecretKey as PhoenixSecretKey,
+        ViewKey as PhoenixViewKey,
+    },
+};
+use zeroize::Zeroize;
+
+use crate::RNG_SEED;
+
+/// Generates a [`BlsSecretKey`] from a seed and index.
+///
+/// The randomness is generated using [`rng_with_index`].
+#[must_use]
+pub fn derive_bls_sk(seed: &[u8; RNG_SEED], index: u8) -> BlsSecretKey {
+    // note that if we change the string used for the rng, all previously
+    // generated keys will become invalid
+    BlsSecretKey::random(&mut rng_with_index(seed, index, b"BSK"))
+}
+
+/// Generates a [`PhoenixSecretKey`] from a seed and index.
+///
+/// The randomness is generated using [`rng_with_index`].
+#[must_use]
+pub fn derive_phoenix_sk(seed: &[u8; RNG_SEED], index: u8) -> PhoenixSecretKey {
+    // note that if we change the string used for the rng, all previously
+    // generated keys will become invalid
+    PhoenixSecretKey::random(&mut rng_with_index(seed, index, b"PSK"))
+}
+
+/// Generates a [`PheonixPublicKey`] from its seed and index.
+///
+/// First the [`PhoenixSecretKey`] is derived with [`derive_phoenix_sk`], then
+/// the public key is generated from it and the secret key is erased from
+/// memory.
+#[must_use]
+pub fn derive_phoenix_pk(seed: &[u8; RNG_SEED], index: u8) -> PhoenixPublicKey {
+    let mut sk = derive_phoenix_sk(seed, index);
+    let pk = PhoenixPublicKey::from(&sk);
+    sk.zeroize();
+
+    pk
+}
+
+/// Generates a [`PhoenixViewKey`] from its seed and index.
+///
+/// First the [`PhoenixSecretKey`] is derived with [`derive_phoenix_sk`], then
+/// the view key is generated from it and the secret key is erased from memory.
+#[must_use]
+pub fn derive_phoenix_vk(seed: &[u8; RNG_SEED], index: u8) -> PhoenixViewKey {
+    let mut sk = derive_phoenix_sk(seed, index);
+    let vk = PhoenixViewKey::from(&sk);
+    sk.zeroize();
+
+    vk
+}
+
+/// Creates a secure RNG from a seed with embedded index and termination
+/// constant.
+///
+/// First the `seed` and then the little-endian representation of the key's
+/// `index` are passed through SHA-256. A constant is then mixed in and the
+/// resulting hash is then used to seed a `ChaCha12` CSPRNG, which is
+/// subsequently used to generate the key.
+#[must_use]
+pub fn rng_with_index(
+    seed: &[u8; RNG_SEED],
+    index: u8,
+    termination: &[u8],
+) -> ChaCha12Rng {
+    let mut hash = Sha256::new();
+
+    hash.update(seed);
+    hash.update(index.to_le_bytes());
+    hash.update(termination);
+
+    let hash = hash.finalize().into();
+    ChaCha12Rng::from_seed(hash)
+}

wallet-core/src/lib.rs

@@ -0,0 +1,17 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//
+// Copyright (c) DUSK NETWORK. All rights reserved.
+
+//! Types used for interacting with Dusk's transfer and stake contracts.
+
+#![cfg_attr(target_family = "wasm", no_std)]
+#![deny(missing_docs)]
+#![deny(rustdoc::broken_intra_doc_links)]
+#![deny(clippy::pedantic)]
+
+pub mod keys;
+
+/// Length of the seed of the generated rng.
+pub const RNG_SEED: usize = 64;

wallet-core/tests/keys_derive.rs

@@ -0,0 +1,63 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+//
+// Copyright (c) DUSK NETWORK. All rights reserved.
+
+use dusk_bytes::Serializable;
+use wallet_core::keys::{
+    derive_bls_sk, derive_phoenix_pk, derive_phoenix_sk, derive_phoenix_vk,
+};
+
+const SEED: [u8; 64] = [0; 64];
+const INDEX: u8 = 42;
+
+#[test]
+fn test_derive_phoenix_sk() {
+    // it is important that we always derive the same key from a fixed seed
+    let sk_bytes = [
+        192, 40, 206, 139, 173, 105, 38, 165, 46, 165, 183, 119, 137, 5, 199,
+        231, 100, 116, 106, 20, 186, 4, 219, 4, 166, 176, 224, 205, 194, 144,
+        29, 4, 178, 57, 113, 176, 185, 83, 92, 81, 64, 162, 29, 109, 62, 46,
+        187, 89, 67, 203, 201, 29, 226, 183, 28, 242, 72, 0, 125, 186, 224,
+        122, 118, 8,
+    ];
+    assert_eq!(derive_phoenix_sk(&SEED, INDEX).to_bytes(), sk_bytes);
+}
+
+#[test]
+fn test_derive_phoenix_pk() {
+    // it is important that we always derive the same key from a fixed seed
+    let pk_bytes = [
+        41, 66, 141, 44, 149, 148, 109, 187, 53, 86, 81, 73, 144, 160, 221, 82,
+        102, 38, 97, 140, 252, 41, 202, 58, 239, 18, 147, 255, 52, 192, 236,
+        22, 168, 125, 132, 85, 254, 91, 12, 47, 95, 1, 145, 82, 53, 84, 63,
+        140, 110, 187, 85, 142, 241, 70, 3, 40, 102, 246, 30, 186, 24, 146, 4,
+        85,
+    ];
+    assert_eq!(derive_phoenix_pk(&SEED, INDEX).to_bytes(), pk_bytes);
+}
+
+#[test]
+fn test_derive_phoenix_vk() {
+    // it is important that we always derive the same key from a fixed seed
+    let vk_bytes = [
+        192, 40, 206, 139, 173, 105, 38, 165, 46, 165, 183, 119, 137, 5, 199,
+        231, 100, 116, 106, 20, 186, 4, 219, 4, 166, 176, 224, 205, 194, 144,
+        29, 4, 168, 125, 132, 85, 254, 91, 12, 47, 95, 1, 145, 82, 53, 84, 63,
+        140, 110, 187, 85, 142, 241, 70, 3, 40, 102, 246, 30, 186, 24, 146, 4,
+        85,
+    ];
+    assert_eq!(derive_phoenix_vk(&SEED, INDEX).to_bytes(), vk_bytes);
+}
+
+#[test]
+fn test_derive_bls_sk() {
+    // it is important that we always derive the same key from a fixed seed
+    let sk_bytes = [
+        42, 224, 186, 247, 133, 35, 202, 126, 255, 156, 236, 121, 214, 145,
+        228, 32, 100, 62, 129, 203, 16, 27, 213, 244, 143, 5, 123, 23, 202, 17,
+        162, 90,
+    ];
+    assert_eq!(derive_bls_sk(&SEED, INDEX).to_bytes(), sk_bytes);
+}