docs: function parse_RC4Header(blob, length) {
  	var o = {};
  	var vers = o.EncryptionVersionInfo = parse_CRYPTOVersion(blob, 4); length -= 4;
  	if(vers.Major != 1 || vers.Minor != 1) throw 'unrecognized version code ' + vers.Major + ' : ' + vers.Minor;
  	o.Salt = blob.read_shift(16);
  	o.EncryptedVerifier = blob.read_shift(16);
  	o.EncryptedVerifierHash = blob.read_shift(16);
  	return o;
  }