hashPassword static method

String hashPassword(String password, String salt)

This method takes a password and returns a hash calculated with the bcrypt algorithm. The salt is added to enlarge the hash base

Implementation

static String hashPassword(String password, String salt) {
  String realSalt;
  var minor = 0;
  int rounds;
  var off = 0;
  var rs = '';
  if ((salt.codeUnitAt(0) != '\$'.codeUnitAt(0)) ||
      (salt.codeUnitAt(1) != '2'.codeUnitAt(0))) {
    throw Exception('Invalid salt version');
  }
  if (salt.codeUnitAt(2) == '\$'.codeUnitAt(0)) {
    off = 3;
  } else {
    minor = salt.codeUnitAt(2);
    if ((minor != 'a'.codeUnitAt(0)) ||
        (salt.codeUnitAt(3) != '\$'.codeUnitAt(0))) {
      throw Exception('Invalid salt revision');
    }
    off = 4;
  }
  if (salt.codeUnitAt(off + 2) > '\$'.codeUnitAt(0)) {
    throw Exception('Missing salt rounds');
  }
  rounds = int.parse(salt.substring(off, off + 2));
  realSalt = salt.substring(off + 3, off + 25);

  var saltb = _decodeBase64(realSalt, bcryptSaltLen);
  var hashed = BCrypt().encryptRaw(
    Uint8List.fromList(
      (password +
              ((minor >= 'a'.codeUnitAt(0)) ? String.fromCharCode(0) : ''))
          .codeUnits,
    ),
    saltb,
    rounds,
    Uint32List(bfCryptCiphertext.length)..setAll(0, bfCryptCiphertext),
  );
  rs += '\$2';
  if (minor >= 'a'.codeUnitAt(0)) {
    rs += String.fromCharCode(minor);
  }
  rs += '\$';
  if (rounds < 10) {
    rs += '0';
  }
  if (rounds > 30) {
    throw Exception('rounds exceeds maximum (30)');
  }
  rs += rounds.toString();
  rs += '\$';
  rs += _encodeBase64(saltb, saltb.length);
  rs += _encodeBase64(hashed, (bfCryptCiphertext.length * 4) - 1);
  return rs;
}