PasswordProtection.cs

// For complete examples and data files, please go to https://github.com/groupdocs-redaction/GroupDocs.Redaction-for-.NET
public override void Load(System.IO.Stream input)
{
    try
    {
		// check security and load document 

        SetAccessGranted(true);
    }
    catch (SomeSecurityException)
    {
        SetAccessGranted(false);
		// Password, provided with LoadOptions
        if (string.IsNullOrEmpty(Password))
            throw new Exceptions.PasswordRequiredException();
        else
            throw new Exceptions.IncorrectPasswordException();
    }
}