@avalabs/hw-app-avalanche/esm/helper.js

Node API for Avalanche App (Ledger Nano S/X/S+)

import bs58 from 'bs58';

const HARDENED = 2147483648;
function pathCoinType(path) {
  if (!path.startsWith("m")) {
    throw new Error(`Path should start with "m" (e.g "m/44'/5757'/5'/0/3")`);
  }
  const pathArray = path.split("/").slice(1);
  const maybe44 = Number(pathArray[0].slice(0, -1));
  if (maybe44 != 44) {
    throw new Error(`Path's first element should be "44", got ${maybe44} (e.g "m/44'/5757'/5'/0/3")`);
  }
  return pathArray[1];
}
function serializePath(path) {
  if (!path.startsWith("m")) {
    throw new Error(`Path should start with "m" (e.g "m/44'/5757'/5'/0/3")`);
  }
  const pathArray = path.split("/");
  if (pathArray.length !== 6 && pathArray.length !== 5 && pathArray.length !== 4) {
    throw new Error(`Invalid path. (e.g "m/44'/5757'/5'/0/3")`);
  }
  const buf = Buffer.alloc(1 + (pathArray.length - 1) * 4);
  buf.writeUInt8(pathArray.length - 1);
  for (let i = 1; i < pathArray.length; i += 1) {
    let value = 0;
    let child = pathArray[i];
    if (child.endsWith("'")) {
      value += HARDENED;
      child = child.slice(0, -1);
    }
    const childNumber = Number(child);
    if (Number.isNaN(childNumber)) {
      throw new Error(`Invalid path : ${child} is not a number. (e.g "m/44'/461'/5'/0/3")`);
    }
    if (childNumber >= HARDENED) {
      throw new Error("Incorrect child value (bigger or equal to 0x80000000)");
    }
    value += childNumber;
    buf.writeUInt32BE(value, 1 + 4 * (i - 1));
  }
  return buf;
}
function serializePathSuffix(path) {
  if (path.startsWith("m")) {
    throw new Error('Path suffix do not start with "m" (e.g "0/3")');
  }
  const pathArray = path.split("/");
  if (pathArray.length !== 2) {
    throw new Error('Invalid path suffix. (e.g "0/3")');
  }
  const buf = Buffer.alloc(1 + pathArray.length * 4);
  buf.writeUInt8(pathArray.length);
  for (let i = 0; i < pathArray.length; i += 1) {
    let value = 0;
    const child = pathArray[i];
    if (child.endsWith("'")) {
      throw new Error('Invalid hardened path suffix. (e.g "0/3")');
    }
    const childNumber = Number(child);
    if (Number.isNaN(childNumber)) {
      throw new Error(`Invalid path : ${child} is not a number. (e.g "0/3")`);
    }
    if (childNumber >= HARDENED) {
      throw new Error("Incorrect child value (bigger or equal to 0x80000000)");
    }
    value += childNumber;
    buf.writeUInt32BE(value, 1 + 4 * i);
  }
  return buf;
}
function serializeHrp(hrp) {
  if (hrp) {
    const bufHrp = Buffer.from(hrp, "ascii");
    return Buffer.concat([new Uint8Array(Buffer.alloc(1, bufHrp.length)), new Uint8Array(bufHrp)]);
  } else {
    return Buffer.alloc(1, 0);
  }
}
function serializeChainID(chainid) {
  if (chainid) {
    let decoded = bs58.decode(chainid);
    if (decoded.length == 36) {
      decoded = decoded.slice(0, 32);
    } else if (decoded.length != 32) {
      throw Error("ChainID was not 32 bytes long (encoded with base58)");
    }
    return Buffer.concat([new Uint8Array(Buffer.alloc(1, decoded.length)), new Uint8Array(Buffer.from(decoded))]);
  } else {
    return Buffer.alloc(1, 0);
  }
}

export { pathCoinType, serializeChainID, serializeHrp, serializePath, serializePathSuffix };