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OfficerBreaker – pptx/docx/xlsx password remover

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Re: OfficerBreaker – pptx/docx/xlsx password remover

#3
post #2

Reading through it quickly, it looks like this is for files that are available to read, but write-protected? Not read-protected documents like a password protected Excel workbook?

A modern read-protected Office document is AES encrypted, so you cannot read those at all. But the read-only one, much like PDF do-not-print/do-not-copy protections, is just relying on the viewer to honor the protection marker.

Re: OfficerBreaker – pptx/docx/xlsx password remover

#4
post #2

Reading through it quickly, it looks like this is for files that are available to read, but write-protected? Not read-protected documents like a password protected Excel workbook?

A modern read-protected Office document is AES encrypted, so you cannot read those at all. But the read-only one, much like PDF do-not-print/do-not-copy protections, is just relying on the viewer to honor the protection marker.

Yes I think you can just save the readonly doc to a new writeable doc anyway.

Re: OfficerBreaker – pptx/docx/xlsx password remover

#6
Some «security» features dont need to be secure. This is obviously one of those as the data is readable by all, but only modifiable by «those in the know», but if someone does anyway who cares.

I’ve done hardcoded frontend identity whitelists for authorization. Some times it’s fine to let hackers access stuff, but not the vanilla mass-market browsers. Feature flags etc

Re: OfficerBreaker – pptx/docx/xlsx password remover

#7
post #4

Earlier quoted context omitted.

A modern read-protected Office document is AES encrypted, so you cannot read those at all. But the read-only one, much like PDF do-not-print/do-not-copy protections, is just relying on the viewer to honor the protection marker.

Yes I think you can just save the readonly doc to a new writeable doc anyway.

If that is true, what is the point of this password remover?

Re: OfficerBreaker – pptx/docx/xlsx password remover

#9
post #4

Earlier quoted context omitted.

Yes I think you can just save the readonly doc to a new writeable doc anyway.

If that is true, what is the point of this password remover?

Sometimes document provenance matters and you don't want a copy.

Re: OfficerBreaker – pptx/docx/xlsx password remover

#10
This password specifically refers to "Password to Modify" and Excel 2019 / 365 clearly warn in the reenter password popup:

> Caution: Password to modify is not a security feature. ... Malicious users can edit the file and remove the password.

This type of "protection" is also present in the VBA blobs (where you can change a few bytes and work around the VBA protection)

Saving a file with a password to open actually employs encryption. The exact setting can be tuned with registry settings, but is typically AES-128-CBC.

Saving a file as "read-only" encrypts the file with the standard password "VelvetSweatshop"

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