ethers.js/packages/hdnode/src.ts/index.ts
2021-10-04 11:46:24 -04:00

413 lines
14 KiB
TypeScript

"use strict";
// See: https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki
// See: https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
import { ExternallyOwnedAccount } from "@ethersproject/abstract-signer";
import { Base58 } from "@ethersproject/basex";
import { arrayify, BytesLike, concat, hexDataSlice, hexZeroPad, hexlify } from "@ethersproject/bytes";
import { BigNumber } from "@ethersproject/bignumber";
import { toUtf8Bytes, UnicodeNormalizationForm } from "@ethersproject/strings";
import { pbkdf2 } from "@ethersproject/pbkdf2";
import { defineReadOnly } from "@ethersproject/properties";
import { SigningKey } from "@ethersproject/signing-key";
import { computeHmac, ripemd160, sha256, SupportedAlgorithm } from "@ethersproject/sha2";
import { computeAddress } from "@ethersproject/transactions";
import { Wordlist, wordlists } from "@ethersproject/wordlists";
import { Logger } from "@ethersproject/logger";
import { version } from "./_version";
const logger = new Logger(version);
const N = BigNumber.from("0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141");
// "Bitcoin seed"
const MasterSecret = toUtf8Bytes("Bitcoin seed");
const HardenedBit = 0x80000000;
// Returns a byte with the MSB bits set
function getUpperMask(bits: number): number {
return ((1 << bits) - 1) << (8 - bits);
}
// Returns a byte with the LSB bits set
function getLowerMask(bits: number): number {
return (1 << bits) - 1;
}
function bytes32(value: BigNumber | Uint8Array): string {
return hexZeroPad(hexlify(value), 32);
}
function base58check(data: Uint8Array): string {
return Base58.encode(concat([ data, hexDataSlice(sha256(sha256(data)), 0, 4) ]));
}
function getWordlist(wordlist: string | Wordlist): Wordlist {
if (wordlist == null) {
return wordlists["en"];
}
if (typeof(wordlist) === "string") {
const words = wordlists[wordlist];
if (words == null) {
logger.throwArgumentError("unknown locale", "wordlist", wordlist);
}
return words;
}
return wordlist;
}
const _constructorGuard: any = {};
export const defaultPath = "m/44'/60'/0'/0/0";
export interface Mnemonic {
readonly phrase: string;
readonly path: string;
readonly locale: string;
};
export class HDNode implements ExternallyOwnedAccount {
readonly privateKey: string;
readonly publicKey: string;
readonly fingerprint: string;
readonly parentFingerprint: string;
readonly address: string;
readonly mnemonic?: Mnemonic;
readonly path: string;
readonly chainCode: string;
readonly index: number;
readonly depth: number;
/**
* This constructor should not be called directly.
*
* Please use:
* - fromMnemonic
* - fromSeed
*/
constructor(constructorGuard: any, privateKey: string, publicKey: string, parentFingerprint: string, chainCode: string, index: number, depth: number, mnemonicOrPath: Mnemonic | string) {
logger.checkNew(new.target, HDNode);
/* istanbul ignore if */
if (constructorGuard !== _constructorGuard) {
throw new Error("HDNode constructor cannot be called directly");
}
if (privateKey) {
const signingKey = new SigningKey(privateKey);
defineReadOnly(this, "privateKey", signingKey.privateKey);
defineReadOnly(this, "publicKey", signingKey.compressedPublicKey);
} else {
defineReadOnly(this, "privateKey", null);
defineReadOnly(this, "publicKey", hexlify(publicKey));
}
defineReadOnly(this, "parentFingerprint", parentFingerprint);
defineReadOnly(this, "fingerprint", hexDataSlice(ripemd160(sha256(this.publicKey)), 0, 4));
defineReadOnly(this, "address", computeAddress(this.publicKey));
defineReadOnly(this, "chainCode", chainCode);
defineReadOnly(this, "index", index);
defineReadOnly(this, "depth", depth);
if (mnemonicOrPath == null) {
// From a source that does not preserve the path (e.g. extended keys)
defineReadOnly(this, "mnemonic", null);
defineReadOnly(this, "path", null);
} else if (typeof(mnemonicOrPath) === "string") {
// From a source that does not preserve the mnemonic (e.g. neutered)
defineReadOnly(this, "mnemonic", null);
defineReadOnly(this, "path", mnemonicOrPath);
} else {
// From a fully qualified source
defineReadOnly(this, "mnemonic", mnemonicOrPath);
defineReadOnly(this, "path", mnemonicOrPath.path);
}
}
get extendedKey(): string {
// We only support the mainnet values for now, but if anyone needs
// testnet values, let me know. I believe current sentiment is that
// we should always use mainnet, and use BIP-44 to derive the network
// - Mainnet: public=0x0488B21E, private=0x0488ADE4
// - Testnet: public=0x043587CF, private=0x04358394
if (this.depth >= 256) { throw new Error("Depth too large!"); }
return base58check(concat([
((this.privateKey != null) ? "0x0488ADE4": "0x0488B21E"),
hexlify(this.depth),
this.parentFingerprint,
hexZeroPad(hexlify(this.index), 4),
this.chainCode,
((this.privateKey != null) ? concat([ "0x00", this.privateKey ]): this.publicKey),
]));
}
neuter(): HDNode {
return new HDNode(_constructorGuard, null, this.publicKey, this.parentFingerprint, this.chainCode, this.index, this.depth, this.path);
}
private _derive(index: number): HDNode {
if (index > 0xffffffff) { throw new Error("invalid index - " + String(index)); }
// Base path
let path = this.path;
if (path) { path += "/" + (index & ~HardenedBit); }
const data = new Uint8Array(37);
if (index & HardenedBit) {
if (!this.privateKey) {
throw new Error("cannot derive child of neutered node");
}
// Data = 0x00 || ser_256(k_par)
data.set(arrayify(this.privateKey), 1);
// Hardened path
if (path) { path += "'"; }
} else {
// Data = ser_p(point(k_par))
data.set(arrayify(this.publicKey));
}
// Data += ser_32(i)
for (let i = 24; i >= 0; i -= 8) { data[33 + (i >> 3)] = ((index >> (24 - i)) & 0xff); }
const I = arrayify(computeHmac(SupportedAlgorithm.sha512, this.chainCode, data));
const IL = I.slice(0, 32);
const IR = I.slice(32);
// The private key
let ki: string = null
// The public key
let Ki: string = null;
if (this.privateKey) {
ki = bytes32(BigNumber.from(IL).add(this.privateKey).mod(N));
} else {
const ek = new SigningKey(hexlify(IL));
Ki = ek._addPoint(this.publicKey);
}
let mnemonicOrPath: Mnemonic | string = path;
const srcMnemonic = this.mnemonic;
if (srcMnemonic) {
mnemonicOrPath = Object.freeze({
phrase: srcMnemonic.phrase,
path: path,
locale: (srcMnemonic.locale || "en")
});
}
return new HDNode(_constructorGuard, ki, Ki, this.fingerprint, bytes32(IR), index, this.depth + 1, mnemonicOrPath);
}
derivePath(path: string): HDNode {
const components = path.split("/");
if (components.length === 0 || (components[0] === "m" && this.depth !== 0)) {
throw new Error("invalid path - " + path);
}
if (components[0] === "m") { components.shift(); }
let result: HDNode = this;
for (let i = 0; i < components.length; i++) {
const component = components[i];
if (component.match(/^[0-9]+'$/)) {
const index = parseInt(component.substring(0, component.length - 1));
if (index >= HardenedBit) { throw new Error("invalid path index - " + component); }
result = result._derive(HardenedBit + index);
} else if (component.match(/^[0-9]+$/)) {
const index = parseInt(component);
if (index >= HardenedBit) { throw new Error("invalid path index - " + component); }
result = result._derive(index);
} else {
throw new Error("invalid path component - " + component);
}
}
return result;
}
static _fromSeed(seed: BytesLike, mnemonic: Mnemonic): HDNode {
const seedArray: Uint8Array = arrayify(seed);
if (seedArray.length < 16 || seedArray.length > 64) { throw new Error("invalid seed"); }
const I: Uint8Array = arrayify(computeHmac(SupportedAlgorithm.sha512, MasterSecret, seedArray));
return new HDNode(_constructorGuard, bytes32(I.slice(0, 32)), null, "0x00000000", bytes32(I.slice(32)), 0, 0, mnemonic);
}
static fromMnemonic(mnemonic: string, password?: string, wordlist?: string | Wordlist): HDNode {
// If a locale name was passed in, find the associated wordlist
wordlist = getWordlist(wordlist);
// Normalize the case and spacing in the mnemonic (throws if the mnemonic is invalid)
mnemonic = entropyToMnemonic(mnemonicToEntropy(mnemonic, wordlist), wordlist);
return HDNode._fromSeed(mnemonicToSeed(mnemonic, password), {
phrase: mnemonic,
path: "m",
locale: wordlist.locale
});
}
static fromSeed(seed: BytesLike): HDNode {
return HDNode._fromSeed(seed, null);
}
static fromExtendedKey(extendedKey: string): HDNode {
const bytes = Base58.decode(extendedKey);
if (bytes.length !== 82 || base58check(bytes.slice(0, 78)) !== extendedKey) {
logger.throwArgumentError("invalid extended key", "extendedKey", "[REDACTED]");
}
const depth = bytes[4];
const parentFingerprint = hexlify(bytes.slice(5, 9));
const index = parseInt(hexlify(bytes.slice(9, 13)).substring(2), 16);
const chainCode = hexlify(bytes.slice(13, 45));
const key = bytes.slice(45, 78);
switch (hexlify(bytes.slice(0, 4))) {
// Public Key
case "0x0488b21e": case "0x043587cf":
return new HDNode(_constructorGuard, null, hexlify(key), parentFingerprint, chainCode, index, depth, null);
// Private Key
case "0x0488ade4": case "0x04358394 ":
if (key[0] !== 0) { break; }
return new HDNode(_constructorGuard, hexlify(key.slice(1)), null, parentFingerprint, chainCode, index, depth, null);
}
return logger.throwArgumentError("invalid extended key", "extendedKey", "[REDACTED]");
}
}
export function mnemonicToSeed(mnemonic: string, password?: string): string {
if (!password) { password = ""; }
const salt = toUtf8Bytes("mnemonic" + password, UnicodeNormalizationForm.NFKD);
return pbkdf2(toUtf8Bytes(mnemonic, UnicodeNormalizationForm.NFKD), salt, 2048, 64, "sha512");
}
export function mnemonicToEntropy(mnemonic: string, wordlist?: string | Wordlist): string {
wordlist = getWordlist(wordlist);
logger.checkNormalize();
const words = wordlist.split(mnemonic);
if ((words.length % 3) !== 0) { throw new Error("invalid mnemonic"); }
const entropy = arrayify(new Uint8Array(Math.ceil(11 * words.length / 8)));
let offset = 0;
for (let i = 0; i < words.length; i++) {
let index = wordlist.getWordIndex(words[i].normalize("NFKD"));
if (index === -1) { throw new Error("invalid mnemonic"); }
for (let bit = 0; bit < 11; bit++) {
if (index & (1 << (10 - bit))) {
entropy[offset >> 3] |= (1 << (7 - (offset % 8)));
}
offset++;
}
}
const entropyBits = 32 * words.length / 3;
const checksumBits = words.length / 3;
const checksumMask = getUpperMask(checksumBits);
const checksum = arrayify(sha256(entropy.slice(0, entropyBits / 8)))[0] & checksumMask;
if (checksum !== (entropy[entropy.length - 1] & checksumMask)) {
throw new Error("invalid checksum");
}
return hexlify(entropy.slice(0, entropyBits / 8));
}
export function entropyToMnemonic(entropy: BytesLike, wordlist?: string | Wordlist): string {
wordlist = getWordlist(wordlist);
entropy = arrayify(entropy);
if ((entropy.length % 4) !== 0 || entropy.length < 16 || entropy.length > 32) {
throw new Error("invalid entropy");
}
const indices: Array<number> = [ 0 ];
let remainingBits = 11;
for (let i = 0; i < entropy.length; i++) {
// Consume the whole byte (with still more to go)
if (remainingBits > 8) {
indices[indices.length - 1] <<= 8;
indices[indices.length - 1] |= entropy[i];
remainingBits -= 8;
// This byte will complete an 11-bit index
} else {
indices[indices.length - 1] <<= remainingBits;
indices[indices.length - 1] |= entropy[i] >> (8 - remainingBits);
// Start the next word
indices.push(entropy[i] & getLowerMask(8 - remainingBits));
remainingBits += 3;
}
}
// Compute the checksum bits
const checksumBits = entropy.length / 4;
const checksum = arrayify(sha256(entropy))[0] & getUpperMask(checksumBits);
// Shift the checksum into the word indices
indices[indices.length - 1] <<= checksumBits;
indices[indices.length - 1] |= (checksum >> (8 - checksumBits));
return wordlist.join(indices.map((index) => (<Wordlist>wordlist).getWord(index)));
}
export function isValidMnemonic(mnemonic: string, wordlist?: Wordlist): boolean {
try {
mnemonicToEntropy(mnemonic, wordlist);
return true;
} catch (error) { }
return false;
}
export function getAccountPath(index: number): string {
if (typeof(index) !== "number" || index < 0 || index >= HardenedBit || index % 1) {
logger.throwArgumentError("invalid account index", "index", index);
}
return `m/44'/60'/${ index }'/0/0`;
}