MobiDeDRM - which PID to use?

[franc]

Hello,

i have a BlackBerry with MobiPocket Reader on it.
I bought a ebook in mobipocket.com and downloaded it to my desktop computer. I want to read it in Calibre, but get an error because of DRM.

Now i want to erase the DRM with MobiDeDRM but i don't know which PID to use.
In mobipocket.com i can read under 'Change My PIDs' four different PIDs, one of them for my Desktop PC. But if i use this in mobidrm005.py i just get:

"Error: invalid PID checksum"

I tried the others with the same result. I think i didn't understand the meaning of this PID.
What to do?

Thank you,
Cheers

[wallcraft]

Most likely any of the four PIDs will work. An invalid checksum is sometimes because of 1 vs I or 0 vs O. A PID is 10 characters, the last two of which are the checksum of the first 8. Another common problem is that filenames with spaces must be in quotes.

The latest mobidedrm is (at least) version 0.16. A good source for DRM related info is Apprentice Alf's Blog. Its "tools_" package provides some easy to use wrappers for command line programs like mobidedrm.

[franc]

Ah, Ok, thank you. But tell me one: which of the four PID can i use then?
Does a DRM-ebook can have FOUR PIDs?
This is what i don't understand.
I thought a DRM-bookfile could have exactly ONE PID no more no less.
How is it?

Originally Posted by wallcraft

...An invalid checksum is sometimes because of 1 vs I or 0 vs O...

How could this happen with Copy And Paste?

[franc]

Oh, nice, with the 016 i could deDRM my Book!
It worked with one of the PIDs.
Unfortunately Calibre can't open it. It says: "Loading eBook..." for hours.
Maybe like Alf's Blog said: that not all prc-files can be load.

[GeoffC]

a book can have a number of PIDs linked to them, for instance I have two for mine, one for my PC (mobireader) and one for my Gen3. Fictionwise, for instance, allows each user upto 4 registered PIDs - not too sure about other stores.....

Should I need to do any deDRMing I, therefore, need two PIDs removing from books.

[franc]

Originally Posted by GeoffC

...Should I need to do any deDRMing I, therefore, need two PIDs removing from books.

That means i have to run mobiDeDRM two times (once with each PID)???

[GeoffC]

Originally Posted by franc

That means i have to run mobiDeDRM two times (once with each PID)???

not necessarily, the routine should be able to cope with multiple PIDs, running just the once.....

[franc]

But without any PID it is surely NOT possible to unDRM?

[GeoffC]

Originally Posted by franc

But without any PID it is surely NOT possible to unDRM?

I'm not too sure what you are saying here....

Have you managed to delete any of the PIDs - not too sure why you should have 4 .... you, by rights should have 2 - one for the mobireader on the Blackberry and mobireader on your PC ? or have I misinterpreted your original post ....

[franc]

I have 4 because: 1 Notebook, 1 PC, 1 old (stolen) BB, 1 new BB.
And because i switched in meantime the notebook now i had to delete old notebook PID and i got the notice to reset the account or something. I did it.

But with my question i meant a totally different thing: if i get a eBook from somewhere else and i don't know the PID of this ebook, then it is not possible to deDRM it?

[Jellby]

In order to deDRM a file, you need the PID it was encoded with/for (if the file is valid for several PID, I guess any single one of the PIDs is enough, but I don't know).

Some mobi files are encoded with no PID (demo and free books), those can be deDRMed without a PID. But if the file was created for an unknown PID, you can't decode it, as far as I know (unless you use brute-force guessing).

[GeoffC]

Originally Posted by Jellby

In order to deDRM a file, you need the PID it was encoded with/for (if the file is valid for several PID, I guess any single one of the PIDs is enough, but I don't know).

Some mobi files are encoded with no PID (demo and free books), those can be deDRMed without a PID. But if the file was created for an unknown PID, you can't decode it, as far as I know (unless you use brute-force guessing).

what's the chance of that !!!

if i get a eBook from somewhere else and i don't know the PID of this ebook, then it is not possible to deDRM it?

As Jellby points out, no - If you don't know the PID - then ..... (one of the reasons/drawbacks of DRM - even if you own the book !).

Is it possible to go back to the store you bought it from and download it again, with the new PID....

[Jellby]

Originally Posted by GeoffC

what's the chance of that !!!

The chance of using brute-force or the chance of succeeding?

Let's see... 8 independent characters... what are the allowed characters in the PID, digits and uppercase letters only? Then that's 36^8 possibilities, or almost 3 billion (3 trillion for Americans). If you can try one per second, in 45000 years you'll have tried half of them, and you might have been lucky already

[boothy]

Hi Franc

I am no expert with mobidedrm but I found that the plugin did not work with just one of my current PIDs (On most ebook stores I have 3) - when I input all 3 PIDs separated by commas it worked fine.As stated in previous post - if you can it would be better to go back to ebook store website and delete redundant PIDs and re download books if possible using the remaining PIDs inserted into plugin customisation.

Boothy

[franc]

Now i just tried again to deDRM a prc-File with only one PID, i used mobidedrm016.py, but even the script told me that the file is deDRM now:

c:\Python27>python mobidedrm016.py mybook_with_drm.prc mybook_without_drm.prc ABCDEFGHIJK
MobiDeDrm v0.16. Copyright 2008-2010 The Dark Reverser.
MOBI header version = 6, length = 232
Extra Data Flags = 2
Decrypting. Please wait . . . . done

... but calibre 0.7.15 tells me, that it is still encrypted.
What is wrong there?