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Question and Answer

Connor McDonald

Thanks for the question, jesu.

Asked: July 03, 2024 - 9:01 am UTC

Last updated: July 04, 2024 - 6:39 am UTC

Version: Oracle Database 19c Enterprise Edition Release

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You Asked

Hello. I have an application in which users upload PDFs to a table. How can I check in PL/SQL if a PDF in a blob is digitally signed?
Ideally I'd like to know if the signature is valid, but just knowing if a file is not signed would be enough to reject it and save manual work.


and Connor said...

I don't think we have anything natively in the database that can do that.

I've seen suggestions on some forums that a signed PDF will have the tag "/Sigflags" in the PDF, so you could look for that using DBMS_LOB.INSTR, but I can't vouch for the validity of that.

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