private Boolean FilterCallback(IntPtr sendDataPtr, IntPtr replyDataPtr)
{
bool retVal = true;
try
{
FilterAPI.MessageSendData messageSend = new FilterAPI.MessageSendData();
messageSend = (FilterAPI.MessageSendData)Marshal.PtrToStructure(sendDataPtr, typeof(FilterAPI.MessageSendData));
if (FilterAPI.MESSAGE_SEND_VERIFICATION_NUMBER != messageSend.VerificationNumber)
{
EventManager.WriteMessage(139, "FilterCallback", EventLevel.Error, "Received message corrupted.Please check if the MessageSendData structure is correct.");
return(false);
}
if (messageSend.MessageType == (uint)FilterAPI.FilterCommand.FILTER_REQUEST_ENCRYPTION_IV_AND_KEY)
{
if ((replyDataPtr.ToInt64() != 0))
{
//this is the customized tag data which was attahced to the encrypted file when it was created.
uint tagDataLength = messageSend.DataBufferLength;
byte[] tagData = messageSend.DataBuffer;
FilterAPI.MessageReplyData messageReply = (FilterAPI.MessageReplyData)Marshal.PtrToStructure(replyDataPtr, typeof(FilterAPI.MessageReplyData));
messageReply.MessageId = messageSend.MessageId;
messageReply.MessageType = messageSend.MessageType;
//get permission for secure shared file from server, here just demo the server in local,
//in reality, your server could be in remote computer.
retVal = DRServer.GetFileAccessPermission(ref messageSend, ref messageReply);
if (retVal)
{
messageReply.ReturnStatus = (uint)FilterAPI.NTSTATUS.STATUS_SUCCESS;
}
else
{
//if you don't want to authorize the process to read the encrytped file,you can set the value as below:
messageReply.ReturnStatus = (uint)FilterAPI.NTSTATUS.STATUS_ACCESS_DENIED;
messageReply.FilterStatus = (uint)FilterAPI.FilterStatus.FILTER_COMPLETE_PRE_OPERATION;
}
Marshal.StructureToPtr(messageReply, replyDataPtr, true);
if (!retVal)
{
messageSend.Status = (uint)FilterAPI.NTSTATUS.STATUS_ACCESS_DENIED;
}
}
}
filterMessage.AddMessage(messageSend);
}
catch (Exception ex)
{
EventManager.WriteMessage(134, "FilterCallback", EventLevel.Error, "filter callback exception." + ex.Message);
return(false);
}
return(retVal);
}
