Finding encrypted PDF files

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daphnis
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Finding encrypted PDF files

Post by daphnis »

Is there a way on the back-end to scan and identify which PDFs and the pages to which they link that are encrypted? We really should make it a point to have only decrypted PDFs available on the site. I'd be glad to do the decrypting if we can identify en masse which ones need fixin'.
Leonard Vertighel
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Re: Finding encrypted PDF files

Post by Leonard Vertighel »

Just a quick remark: these files aren't actually encrypted, otherwise you'd need a key even to read them. They just have a flag which tells compliant software to disable certain functions like printing. The thing to find out is how this flag is stored, and if maybe finding those files is as easy as "grepping" for a certain string. I'll try googling.....
Johann Casper Ferdinand F
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Re: Finding encrypted PDF files

Post by Johann Casper Ferdinand F »

I have a list. Would you like me to post it here, send it to you, or post it on the wiki?
daphnis
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Re: Finding encrypted PDF files

Post by daphnis »

I see. Well, if they can be found I could start the "deflagging" process and replace.
Carolus
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Re: Finding encrypted PDF files

Post by Carolus »

If you create a small template that simply states "Locked PDF" there is a way to easily create a category page so that any page with the template will be listed. Keep in mind that encryption is fine for non-PD works which have been submitted by the composer, etc. Ideally, all public domain items should be unlocked.
Johann Casper Ferdinand F
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Re: Finding encrypted PDF files

Post by Johann Casper Ferdinand F »

http://imslp.org/wiki/User:Johann_Caspa ... ocked_PDFs - and I apologize for the munged UTF-8 characters.
Leonard Vertighel
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Re: Finding encrypted PDF files

Post by Leonard Vertighel »

Tried to fix the characters - windows cp 1252 seemed to be the closest match, had to manually fix a few characters like "?" and "?" though. Some links are still red however. How did you make the list?
Johann Casper Ferdinand F
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Re: Finding encrypted PDF files

Post by Johann Casper Ferdinand F »

:mrgreen: :mrgreen: :mrgreen:

From the error logs of a script that calculates page counts. It is a side effect of a much larger and more important effort, the details of which I will be announcing here in a few days.
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