Ask php how to determine if the pdf file is encrypted

Source: Internet
Author: User
How does php determine whether a pdf file is encrypted is a permission password, that is, it can be viewed and cannot be modified? I am working on a conversion program. if it is encrypted, it will be stuck there, if the problem persists, the project may be aborted ..., after encryption, there will be an encrypted sign. if you know the encryption principle, you can find the encryption sign to the language in which it is used. this is not a problem. how does php determine whether the pdf file is encrypted?
It is a permission password that can be viewed and cannot be modified.

I am working on a conversion program. if it is encrypted, it will be stuck there. if it is not solved, it may directly lead to a project abortion...

------ Solution --------------------
Encrypted, there will be a sign of encryption
If you know the encryption principle, you can find the encryption mark.
So what language is used is not a problem

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.