Sometimes I get password-protected pdf files from people with passwords in the mail. It becomes a pain to remember them. The pdf file are usually version 1.4 documents, this information I am sharing is in relation to my earlier question. Now my question is, is there a way to extract and make a new pdf file from the pdf file, this time without password-protection. I am guessing pdftk could be useful here.
It depends a bit on what kind of pw is set on the pdf. There are user, owner and input passwords.
pdftk input.pdf output output.pdf user_pw YOURPASSWORD-HERE
with user and ownerpw
pdftk input.pdf output output.pdf user_pw YOURPASSWORD-HERE owner_pw YOURPASSWORD-HERE
for input pw:
pdftk input.pdf output output.pdf input_pw YOURPASSWORD-HERE
for more detailed information you can read up here: https://www.cyberciti.biz/faq/removing-password-from-pdf-on-linux/