"invalid PID checksum" when using mobidedrm, even though it IS valid.

[wallcraft]

Originally Posted by mindwarp

I continue to get Invalid PID Checksum.

Try using pid_checksum.py. Note that 0 vs O and 1 vs I are common errors, although in this case there is also the possibility that kindlepid returned the wrong PID (because it was given the wrong UDID).

Also, make sure you don't have Python 3.X which does not work.

[mindwarp]

Originally Posted by wallcraft

Try using pid_checksum.py. Note that 0 vs O and 1 vs I are common errors, although in this case there is also the possibility that kindlepid returned the wrong PID (because it was given the wrong UDID).

Also, make sure you don't have Python 3.X which does not work.

Thanks for the reply.

I've tried pid_checksum and it said Mobipocket PID is correct. There are no 0 or 1 in my PID so I'm clear there. I'm using python 2.6.2.

I'm beginning to think that the wrong PID must have been generated from my Ipod UDID, cause I'm running out of ideas. lol

[wallcraft]

Originally Posted by mindwarp

I'm beginning to think that the wrong PID must have been generated from my Ipod UDID, cause I'm running out of ideas.

I agree, because it is unlikely that a "random" PID-like string has a good checksum. Try generating the PID from the UDID again.

[wallcraft]

Originally Posted by mindwarp

Error: invalid PID checksum

This is confusing, because pid_checksum.py with EXACTLY the same command line (right?), i.e. with mobidedrm005.py replaced with pid_checksum.py, did not give a checksum error.

[mindwarp]

Originally Posted by wallcraft

This is confusing, because pid_checksum.py with EXACTLY the same command line (right?), i.e. with mobidedrm005.py replaced with pid_checksum.py, did not give a checksum error.

Right. I typed it up here wrong, but it has the exact same command line just replacing mobidedrm005.py with pid_checksum.py.

I tried seeing if I had another UDID anywhere or if it would change if I restored my Ipod, but it didn't. I really have no clue, because the checksum says it's correct.

I've tried different files and typed in different extensions (.azw and .prc) But no avail.

Thanks for the suggestions!

[wallcraft]

Originally Posted by mindwarp

But no avail.

Try the suggestion in post #4. This it isn't much but it is all I have left.

[mindwarp]

Originally Posted by wallcraft

Try the suggestion in post #4. This it isn't much but it is all I have left.

Thanks I did find something odd. I tried the sample PID given with pid_checksum and typed it in instead of my PID and it came out as correct.... and when I posted it with mobidedrm005.py it said invalid PID checksum instead of what it should have said (Error: no key found. maybe the PID is incorrect).

I don't know what that means, but I found that odd. Even if you don't have any more ideas, thanks so much for trying to help!

[mindwarp]

I finally got one to work! lol It seems that all the kindle books I was using came up as invalid file type when I used mobidedrm.py (when I used mobidedrm005.py it said invalid PID) I download quite a few free kindle ebooks and samples and tested them out. Some worked with mobidedrm.py but none worked with mobidedrm005.py.

I haven't figured out why only some will work, but none with the newer mobidedrm.

I did notice that if the sample was drmed then I couldn't undrm the full book, but if the sample wasn't drmed then I could undrm the full book. Not sure why that is though... lol

Thanks again, wallcraft!

[wallcraft]

Originally Posted by mindwarp

I finally got one to work! lol It seems that all the kindle books I was using came up as invalid file type when I used mobidedrm.py (when I used mobidedrm005.py it said invalid PID) I download quite a few free kindle ebooks and samples and tested them out. Some worked with mobidedrm.py but none worked with mobidedrm005.py.

You may have a corrupted version of v5, but I have suspected in other cases on the Mac that the "checksum" error is coming up when some other error is actually invoked. You seem to have confirmed this.

DRM-free AZW's should give a different error, but they don't need mobidedrm at all. I was not aware that any samples had DRM. Are the ebooks (samples or otherwise) that fail completely TOPAZ ebooks (file extension .tpz or .azw1)? This is an Amazon-specific format that no one outside Amazon knows how to read.

See kindledrm.py for a script to identify DRM-free AZW ebooks.

[mindwarp]

Originally Posted by wallcraft

DRM-free AZW's should give a different error, but they don't need mobidedrm at all. I was not aware that any samples had DRM. Are the ebooks (samples or otherwise) that fail completely TOPAZ ebooks (file extension .tpz or .azw1)? This is an Amazon-specific format that no one outside Amazon knows how to read.

See kindledrm.py for a script to identify DRM-free AZW ebooks.

Hey! Yep, the books I was trying to convert that came up with checksum error were all Tpz. Both in Samples and the Full book. Seems I had a lot of this format and I wasn't aware. Paul was gracious enough to show me how to figure out what format it's in. I didn't know, because when you extract from an IPhone/Itouch the format is always .prc. No matter if it's azw, azw1 or tpz. Good for future knowledge too anyone that uses this device.

Thanks again

[nohmi2]

Oh frabjous joy!!!

Downloaded two books from PanMcMillan.
Converted one with no trouble at all. Tried to convert the second one (same PID, same method) wrong PID.
Before clocking in here, had a look at our local e-newspaper and this is what greeted me:

Tsunami warning for east coast

is on a tsunami alert following an earthquake off New Zealand.

3 comments on this story

Twitter: Latest tsunami talk

All help with the MobiDeDRM would be appreciated.

Some days it doesn't pay to get up does it?

Cheers

[pdurrant]

Originally Posted by nohmi2

Downloaded two books from PanMcMillan.
Converted one with no trouble at all. Tried to convert the second one (same PID, same method) wrong PID.

Some PanMcMillan ebooks are DRM free. Check to see if it really does have DRM first?

[nohmi2]

Originally Posted by pdurrant

Some PanMcMillan ebooks are DRM free. Check to see if it really does have DRM first?

Will have a look today.

Many thanks.

[nohmi2]

It was DRM free.

I really cannot understand their reasoning, but I will remember that fact when I buy from them again.

Many thanks.

[Dowland]

Here comes a lengthy post to summarize the problem and give an actual solution. Please don't hesitate to reproduce this elsewhere. And also, please don't bury this post in the thread, because then nobody will ever find it ... :-)

*

Background info. A MobiPocket PID is 10 characters: 8 characters are the actual key, and 2 characters are the checksum.

Now, before doing its deed, MobileDRM looks at the PID you gave: it controls whether the checksum and the key actually correspond. If they dont, then it gives the error message we all know ("Error: invalid PID checksum"). If they do, then it cuts away the last 2 characters of the PID, and keeps only the key for the remainder of its operation.

Problem. The issue, at least in mobiledrm005.py, is that it accidentally repeats this operation twice (probably whoever wrote this did an unwitting double copy-paste). So scenario 1: your PID is incorrect, and it gets rejected on the first check. And scenario 2: your PID is correct, it passes the first check, gets shortened to its key component, and then flunks the second check.

Solution. Remove the first block from the initialization the code

Please contact the OP for this code, as we are not allowed to host Python code of this nature on MR. Thanks for your understanding.

Moderator

Outro. It may very well be that your PID is actually incorrect, and you should browse this thread for ways to find out.

Also: opening the book after buying it unnecessary (except if your vendor does some non-standard thing I've never heard about). If this seems like it works, than a possible explanation is that opening the book actually removes the DRM (and then running MobileDRM on it gives the appearance that it actually worked ...).

Finally: no, I've never seen (valid) MobiPocket PIDs with anything but uppercase alphanumerical characters...