Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Office detects a problem with decrypted ppt files #31

Open
MrCrumbs opened this issue Mar 27, 2019 · 5 comments
Open

Office detects a problem with decrypted ppt files #31

MrCrumbs opened this issue Mar 27, 2019 · 5 comments

Comments

@MrCrumbs
Copy link

Thanks for adding support for ppt! Decrypting a simple password-protected ppt file (created by PowerPoint 2013) results in a successful decryption, however when opened by PowerPoint 2013 it launches in Protected View since "Office has detected a problem with this file".

According to Office, one of the reasons to open up in Protected View is:
File validation failure - When you see a message in Protected View that says "Office has detected a problem with this file. Editing it may harm your computer. Click for more details.", the file didn’t pass file validation. File validation scans file for security problems that can result from changes in the file structure.

Has anyone seen this? Would it help to add any more info?

@nolze
Copy link
Owner

nolze commented Apr 4, 2019

Thank you for reporting!

It seems that there is something wrong with the internal structure of the decrypted file.
Unfortunately, as the MS-PPT support is really partial and experimental, there are uncountable possible causes. It is difficult to work on the issue without the file in question for now.

I'll check it if you could you attach the equivalent file (please make sure to remove secrets.) I'd appreciate a fix PR too.

MrCrumbs pushed a commit to MrCrumbs/msoffcrypto-tool that referenced this issue Apr 7, 2019
MrCrumbs pushed a commit to MrCrumbs/msoffcrypto-tool that referenced this issue Apr 7, 2019
@MrCrumbs
Copy link
Author

MrCrumbs commented Apr 7, 2019

Hey, thanks for your reply!
I wasn't sure how exactly you wanted me to do the PR, so I forked and added the encrypted/decrypted sample to "tests" folder... hope that's what you meant.
The sample is not important, I just hope it helps you to find out the root cause... your library is great and for now PPT decryption is the only thing missing for me :)
Thanks so much!

@nolze
Copy link
Owner

nolze commented Apr 15, 2019

Thanks! I confirmed the Protected View alert showing up in the lastest PowerPoint for Windows with the provided file. (It is puzzling that the alert does not show up in PowerPoint for Mac and PowerPoint Online.) I'll investigate it further.

@fsc-eriker
Copy link

For testing, what's the password?

@MrCrumbs
Copy link
Author

I actually don't remember ;)
But you can try with any other encrypted PPT. I uploaded a new sample here (I tried to decrypt it with the same issue). The password, as the filename suggests, is "test".
password_is_test.zip

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Projects
None yet
Development

No branches or pull requests

3 participants