@steemit/steem-js/lib/auth/ecc/src/address.js

JavaScript library for the Steem blockchain

"use strict";

const assert = require('assert');
const config = require('../../../config');
const hash = require('./hash');
const base58 = require('bs58');

/** Addresses are shortened non-reversable hashes of a public key.  The full PublicKey is preferred.
    @deprecated
*/
class Address {
  constructor(addy) {
    this.addy = addy;
  }
  static fromBuffer(buffer) {
    const _hash = hash.sha512(buffer);
    const addy = hash.ripemd160(_hash);
    return new Address(addy);
  }
  static fromString(string, address_prefix = config.get('address_prefix')) {
    const prefix = string.slice(0, address_prefix.length);
    assert.equal(address_prefix, prefix, `Expecting key to begin with ${address_prefix}, instead got ${prefix}`);
    let addy = string.slice(address_prefix.length);
    addy = new Buffer.from(base58.decode(addy), 'binary');
    const checksum = addy.slice(-4);
    addy = addy.slice(0, -4);
    let new_checksum = hash.ripemd160(addy);
    new_checksum = new_checksum.slice(0, 4);
    assert.deepEqual(checksum, new_checksum, 'Checksum did not match');
    return new Address(addy);
  }

  /** @return Address - Compressed PTS format (by default) */
  static fromPublic(public_key, compressed = true, version = 56) {
    const sha2 = hash.sha256(public_key.toBuffer(compressed));
    const rep = hash.ripemd160(sha2);
    const versionBuffer = new Buffer.alloc(1);
    versionBuffer.writeUInt8(0xFF & version, 0);
    const addr = Buffer.concat([versionBuffer, rep]);
    let check = hash.sha256(addr);
    check = hash.sha256(check);
    const buffer = Buffer.concat([addr, check.slice(0, 4)]);
    return new Address(hash.ripemd160(buffer));
  }
  toBuffer() {
    return this.addy;
  }
  toString(address_prefix = config.get('address_prefix')) {
    const checksum = hash.ripemd160(this.addy);
    const addy = Buffer.concat([this.addy, checksum.slice(0, 4)]);
    return address_prefix + base58.encode(addy);
  }
}
module.exports = Address;