code: public boolean setNewPassword(String oldPwd, String newPwd) {
      	boolean result = false;
      	if (this.protectionHash.equals(RtfProtection.generateHash(oldPwd))) {
      		this.protectionHash = RtfProtection.generateHash(newPwd);
      		result = true;
      	}
      	return result;
      }
docs: Author: Howard Shank (hgshank@yahoo.com)
  @param oldPwd Old password - clear text
  @param newPwd New password - clear text
  @return true if password set, false if password not set
  @since 2.1.1