如何打开受编程保护的 PDF 文件 [不受密码保护]

Question

There is a android app named taaghche which you can purchase and read pdf books etc...

I purchased a book and I want to be able to read it on PC not android, and also be able to highlight the text (which is not allowed in the app), But The app stores the pdfs so that the pdf files only opens in the app itself and if you try to open the pdf in another device you'll get the error:

Note that the app actually stores the pdf along with a file with no extension and the same name.

I think the app uses the file with no extension to give permission to the pdf file to be opened.

Here is the two files in a zip to download and have a look.

http://langfox.ir/download/pdfs.zip

Any idea or solution or clue to open this file is greatly appreciated.

Answer 1

The pdf looks encoded/encrypted (I maybe wrong) but I would expect to see a Pdf header, and I don't.

The file without an extension is a JFIF file (JPEG File Interchange Format), if you change the extension to Jpg, or JFIF, you should be able to view it as an image. Or in C# you can just use the Bitmap or Image class to load it

Image.FromFile(theFileName);