@airgap/crypto/secp256k1/derive.js

The @airgap/crypto packages provides common crypto functionalities.

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.deriveSecp256K1 = void 0;
var sha512_1 = require("@airgap/coinlib-core/dependencies/src/@stablelib/sha512-1.0.1/packages/sha512/sha512");
// @ts-ignore
var elliptic_1 = __importDefault(require("@airgap/coinlib-core/dependencies/src/secp256k1-4.0.2/elliptic"));
var hmac_1 = require("@stablelib/hmac");
var derivation_1 = require("../utils/derivation");
var hash_1 = require("../utils/hash");
var BITCOIN_KEY = 'Bitcoin seed';
function deriveSecp256K1(seed, derivationPath, key) {
    if (key === void 0) { key = BITCOIN_KEY; }
    var masterNode = masterNodeFromSeed(seed, key);
    return derivationPath !== undefined ? derive(masterNode, derivationPath) : masterNode;
}
exports.deriveSecp256K1 = deriveSecp256K1;
function masterNodeFromSeed(seed, key) {
    var _a = getKey(seed, Buffer.from(key, 'utf-8')), secretKey = _a.key, chainCode = _a.chainCode;
    return {
        depth: 0,
        parentFingerprint: 0x00000000,
        index: 0,
        chainCode: chainCode,
        secretKey: secretKey,
        publicKey: getPublicKey(secretKey)
    };
}
function derive(masterNode, derivationPath) {
    var derivationIndices = (0, derivation_1.splitDerivationPath)(derivationPath);
    return derivationIndices.reduce(deriveChild, masterNode);
}
function deriveChild(node, derivationIndex) {
    var parentFingerprint = (0, hash_1.hash160)(node.publicKey).readUInt32BE(0);
    var index = derivationIndex.masked;
    var indexBuffer = Buffer.alloc(4);
    indexBuffer.writeUInt32BE(index);
    var data = derivationIndex.isHardened
        ? Buffer.concat([Buffer.alloc(1, 0), node.secretKey, indexBuffer])
        : Buffer.concat([node.publicKey, indexBuffer]);
    var _a = getKey(data, node.chainCode), key = _a.key, chainCode = _a.chainCode;
    try {
        var ki = Buffer.from(elliptic_1.default.privateKeyTweakAdd(Buffer.from(node.secretKey), key));
        return {
            depth: node.depth + 1,
            parentFingerprint: parentFingerprint,
            index: index,
            chainCode: chainCode,
            secretKey: ki,
            publicKey: getPublicKey(ki)
        };
    }
    catch (_b) {
        return deriveChild(node, (0, derivation_1.incIndex)(derivationIndex));
    }
}
function getKey(data, key) {
    var I = Buffer.from((0, hmac_1.hmac)(sha512_1.SHA512, key, data));
    var IL = I.slice(0, 32);
    var IR = I.slice(32);
    return { key: IL, chainCode: IR };
}
function getPublicKey(privateKey) {
    var publicKey = elliptic_1.default.publicKeyCreate(privateKey, true);
    return Buffer.from(publicKey);
}
//# sourceMappingURL=derive.js.map