David Zhang - Encrypting and decrypting PDFs using QPDF

Saturday, March 14, 2020

If you have a password-protected PDF and want to generate a decrypted version, it’s very simple with QPDF:

$ qpdf --password=123 --decrypt input.pdf output.pdf

To avoid entering the password on the command line (perhaps you don’t want it saved in your shell history):

$ qpdf @- --decrypt input.pdf output.pdf

Then enter --password=123 and hit enter and ^D.

To encrypt a PDF, do this:

$ qpdf --encrypt userPw ownerPw 256 -- input.pdf output.pdf

Similarly, to avoid including the passwords in the command, do this:

$ qpdf --encrypt @- @- 256 -- input.pdf output.pdf

And then type the user password, hit enter, the owner password, enter, and ^D.

Tags: pdf | Posted at 22:04 | Comments (10)

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Encrypting and decrypting PDFs using QPDF

Saturday, March 14, 2020

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