bitcoinjs-lib/src/eckey.js

Bitcoin.ECKey = (function () {
  var ECDSA = Bitcoin.ECDSA;
  var ecparams = getSECCurveByName("secp256k1");
  var rng = new SecureRandom();

  var ECKey = function (input) {
    if (!input) {
      // Generate new key
      var n = ecparams.getN();
      this.priv = ECDSA.getBigRandom(n);
    } else if (input instanceof BigInteger) {
      // Input is a private key value
      this.priv = input;
    } else if (Bitcoin.Util.isArray(input)) {
      // Prepend zero byte to prevent interpretation as negative integer
      this.priv = BigInteger.fromByteArrayUnsigned(input);
    } else if ("string" == typeof input) {
      // Prepend zero byte to prevent interpretation as negative integer
      this.priv = BigInteger.fromByteArrayUnsigned(Crypto.util.base64ToBytes(input));
    }
  };

  ECKey.prototype.getPub = function () {
    if (this.pub) return this.pub;

    return this.pub = ecparams.getG().multiply(this.priv).getEncoded();
  };

  /**
   * Get the pubKeyHash for this key.
   *
   * This is calculated as RIPE160(SHA256([encoded pubkey])) and returned as
   * a byte array.
   */
  ECKey.prototype.getPubKeyHash = function () {
    if (this.pubKeyHash) return this.pubKeyHash;

    return this.pubKeyHash = Bitcoin.Util.sha256ripe160(this.getPub());
  };

  ECKey.prototype.getBitcoinAddress = function () {
    var hash = this.getPubKeyHash();
    var addr = new Bitcoin.Address(hash);
    return addr;
  };

  ECKey.prototype.setPub = function (pub) {
    this.pub = pub;
  };

  ECKey.prototype.toString = function (format) {
    if (format === "base64") {
      return Crypto.util.bytesToBase64(this.priv.toByteArrayUnsigned());
    } else {
      return Crypto.util.bytesToHex(this.priv.toByteArrayUnsigned());
    }
  };

  ECKey.prototype.sign = function (hash) {
    return ECDSA.sign(hash, this.priv);
  };

  ECKey.prototype.verify = function (hash, sig) {
    return ECDSA.verify(hash, sig, this.getPub());
  };

  return ECKey;
})();