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

[Surfergirl]

The PID for a Windows PC often (always?) has a $ as the 8th character, and I think this is what is causing the problem.

I've got this problem - my PID is from a PC and has a $ as the 8th character. I'm fairly computer literate, but don't know anything about Python and am not sure what changes need to be made to the mobidrdrm program.

If I send my PID to someone, could they run it through the calculation script, and tell me what the correct PID actually is? I'm desparate to get the DRM-stripping working, as a book is due to be released very soon which is only available in MOBI (and I've got a Sony Reader!)

Thanks, Irene

[llasram]

Originally Posted by Surfergirl

I've got this problem - my PID is from a PC and has a $ as the 8th character. I'm fairly computer literate, but don't know anything about Python and am not sure what changes need to be made to the mobidrdrm program.

What platform are you running mobidedrm on? Looking back over this thread it looks to me like everyone having this problem was running OS X or GNU/Linux and wasn't putting their $-containing PID in single quotes. Did you you try that?

Hope this helps!,

-Marshall

[=X=]

Originally Posted by Surfergirl

The PID for a Windows PC often (always?) has a $ as the 8th character, and I think this is what is causing the problem.

I've got this problem - my PID is from a PC and has a $ as the 8th character.

Thanks, Irene

Hi Surfergirl, look back to post #15 & #13 have the answer to your problem.
Your PC PID is a 10 digit, where the eight digit is a $, put your PID in single quotes and drop of the last two char so if your PID. So if your PID is 1234567$90 change it to '1234567$' (include single quotes).

=X=

[JSWolf]

Or create a PID you can use without a $ and add that to your list of PIDs so when you do go to use MobiDeDRM.py, you won't have to worry about a $.

[Leep]

Have you tried Pdurrants hack to fix a couple of mobidedrm issues?
https://www.mobileread.com/forums/sho...4&postcount=76

[wallcraft]

Originally Posted by Surfergirl

The PID for a Windows PC often (always?) has a $ as the 8th character, and I think this is what is causing the problem.

I've got this problem - my PID is from a PC and has a $ as the 8th character.

If putting the full 10-digit PID in single quotes does not work, then check to see if you have mistyped 1 for I or 0 for O (or I for 1, O for 0).

[Surfergirl]

Originally Posted by llasram

What platform are you running mobidedrm on? Looking back over this thread it looks to me like everyone having this problem was running OS X or GNU/Linux and wasn't putting their $-containing PID in single quotes. Did you you try that?

Hope this helps!,

-Marshall

Hi. Yep - tried that. Still comes back with "Invalid PID checksum". And I'm running on Windows XP.

Irene

[Surfergirl]

Originally Posted by =X=

Hi Surfergirl, look back to post #15 & #13 have the answer to your problem.
Your PC PID is a 10 digit, where the eight digit is a $, put your PID in single quotes and drop of the last two char so if your PID. So if your PID is 1234567$90 change it to '1234567$' (include single quotes).

=X=

Hi. Unfortunately, tried that already - still just comes back with "invalid PID checksum".

[Surfergirl]

Originally Posted by JSWolf

Or create a PID you can use without a $ and add that to your list of PIDs so when you do go to use MobiDeDRM.py, you won't have to worry about a $.

Hi Jon. I know this must sound like a real dumb question, but how do I create a new PID??

Thanks, Irene

[JSWolf]

Do you maybe have access to a Windows machine to try this on?

[Surfergirl]

Originally Posted by JSWolf

Do you maybe have access to a Windows machine to try this on?

I'm using a Windows XP machine!

[wallcraft]

One problem with mobidedrm is that it does not do any "sanity checking" of its arguments. This would normally be easy to fix, but modifying mobidedrm.py is not legal in the US. So I attach argecho.py from Dive Into Python. If you have problems with mobidedrm, or any other python script, replace the command with argecho. This is almost the simplest possible python program. All it does is echo its arguments, one per line with the 1st line being the command name. For example:

C:\Documents and Settings\alan\My Documents\My eBooks\SOFTWARE>argecho test file.prc test file.mobi V176CXM*FZ
C:\Documents and Settings\alan\My Documents\My eBooks\SOFTWARE\argecho.py
test
file.prc
test
file.mobi
V176CXM*FZ

This first attempt did not have quotes around the filename, and so what should have been 3 arguments became 5 arguments and the third argument (4th output line) is "test" instead of "V176CXM*FZ". The 1st line of output starts with "C:" because I have argecho.py in the current directory. Adding quotes around the filenames gives the expected 3 arguments.

C:\Documents and Settings\alan\My Documents\My eBooks\SOFTWARE>argecho "test file.prc" "test file.mobi" V176CXM*FZ
C:\Documents and Settings\alan\My Documents\My eBooks\SOFTWARE\argecho.py
test file.prc
test file.mobi
V176CXM*FZ

There are no doubt many better ways to debug python scripts than using argecho, but using argecho would have made finding past issues with mobidedrm (for example) much easier.

[pdurrant]

Best to use my second set of hacks, which actually fix the problem rather than masking it :-)

https://www.mobileread.com/forums/sho...&postcount=125

Paul

Originally Posted by Leep

Have you tried Pdurrants hack to fix a couple of mobidedrm issues?
https://www.mobileread.com/forums/sho...4&postcount=76

[Surfergirl]

Thank you to everyone who has chipped in with suggestions for my problem.

Argecho.py confirms that I'm using the correct number of arguments to the Python script, I've updated MobiDeDrm using pdurrant's list of changes. I've even tried reinstalling Python from scratch, in case something got screwed in the initial install .... unfortunately, I just keep getting the "invalid PID" error with both of my PIDs. I can't think of anything else to try, so I think I'm just going to have to write this off as a bad job - it's just incredibly frustrating when other people get the script to work without a problem.

My stepson is a Mac addict, so I might try running the script on his machine if he's got Python installed.

Thanks again for all your help
Irene

[dickon25]

Originally Posted by red_dragon

You could disable the PID check and examine what mobidedrm expects. After making the changes you have to pass a 8 char PID to the python program:

(Be careful with the indentions)

	def __init__(self, data_file, pid):
### BEGIN NEW CODE ###
		# Calculate PID checksum if just the first 8 chars are specified
		if len(pid) == 8:
			pid = checksumPid(pid)
			print "Full PID is %s" % pid
### END NEW CODE ###
		if checksumPid(pid[0:-2]) != pid:
			raise DrmException("invalid PID checksum")
		pid = pid[0:-2]

Does it work for you?

If the decrypted result is garbage then your PID is not correct.

-Red Dragon

When I try this, inputting the shortened 8 digit PID, it tells me the correct PID is the 10 digit 'abc123...' - which is exactly what it rejected in the first place!
It then gives me 'invalid PID checksum' and does not convert.

I'm using v0.4 of MobideDRM and the PID is for a Windows PC running XP.

Does anyone have any other ideas, please?

Thanks