Password to modify is lost during conversion from legacy format to OOXML

Aspose.Slides Product Family
1

Hi,


I noticed that password to modify is lost during conversion from legacy format to OOXML, for example from PPT to PPTX.

Is it a bug? Or it is not possible to implement. Aspose.Words and Excel maintain password to modify when converting legacy formats to OOXML.

Thanks,
Alex
2

Hi Alex,

I have observed the information shared by you and request you to please share the source presentation, generated presentation and used sample code. We will be able to investigate the issue further on our end on provision of requested information.

Many Thanks,

3
Hi,

Thanks you for a quick replay.

I found out that password to modify was removed because I invoked ProtectionManager.RemoveEncryption method. But still, is't it wrong behavior? There is another method for removing password to modify - RemoveWriteProtection. RemoveEncryption designed to remove password to open. Am I right?

Back to original issue. I commented out RemoveEncryption call and faced with another issue - NullReferenceException is thrown:

var pr = new Presentation("ppt_M.ppt", new Aspose.Slides.LoadOptions {});
//pr.ProtectionManager.RemoveEncryption();
pr.Save("ppt_M.ppt.pptm", SaveFormat.Pptm);

Thanks,
Alex
4

Hi Alex,

I have observed your requirements and have also worked with your sample code and presentation.You have shared a presentation with password which is permissible to load in PowerPoint in readonly mode. In read
only mode, one may not save or make any change in presentation in
PowerPoint.

However, when we load the same presentation (without providing password)
using Aspose.Slides and call RemoveEncryption(), it successfully
removes the encryption and one can save the presentation without any
encryption. I think this is wrong as the RemoveEncrytption() should be
allowed when one should set the password while loading. I have created an issue with SLIDESNET-38920 in our issue tracking system to further investigate and resolve the issue in light of above observation. This thread has been linked with the issue so that you may be automatically notified once the issue will be fixed.

For your second issue in same scenario whereby you try to save a read only presentation without removing protection or providing password, Aspose.Slides is throwing InvalidPasswordException, which is correct behavior.

We are sorry for your inconvenience,

5
Hi,

Thanks for a quick reply.

Mudassir:
Hi Alex,
For your second issue in same scenario whereby you try to save a read only presentation without removing protection or providing password, Aspose.Slides is throwing InvalidPasswordException, which is correct behavior.

Looked at screenshot you provided. Please change SaveFormat to Pptm an you will get ArgumentNullException, not InvalidPasswordException: {"String reference not set to an instance of a String.\r\nParameter name: s"}.

Alex
6

Hi Alex,

I have tried saving the presentation to PPTM and have obtained ArgumentNullException rather than InvalidPassword exception. An issue with ID SLIDESNET-38922 has been added as enhancement in our issue tracking system to further investigate and resolve the issue. This thread has been linked with the issue so that you may be automatically notified once the issue will be fixed.

We are sorry for your inconvenience,

7

Hi,

Is there any update for the following issues:

  1. NullReference exception when saving read-only PPT file to PPTM format.
  2. SLIDESNET-38920
8

@licenses,

I have observed your comments. I regret to inform that issue is still unresolved. We will share details regarding ETA soon. I request for your patience and we will share good news with you soon.

10

The issues you have found earlier (filed as SLIDESNET-38920,SLIDESNET-38922) have been fixed in this update.