emf_decrypter fail on iPhone with complex passcode

[GoogleCodeExporter]

What steps will reproduce the problem?
1.Run "build.py iphone4gsmA" build forensics tools and boot iPhone with custom 
ramdisk.
2.Run "python python_scripts/demo_bruteforce.py" bruteforce passcode.
3.Run "sh ./dump_data_partition.sh" dump user partition disk image.
4.Run "python python_scripts/emf_decrypter.py [UDID]/data_20140522-1512.dmg".

What is the expected output? What do you see instead?
I expect to emf_decrypter decrypt the disk image correct. But goes to fail.

FAIL: AESdecryptCBC _MKBPAYLOAD => wrong BAG1 key ?
Traceback (most recent call last):
  File "python_scripts/emf_decrypter.py", line 35, in <module>
    main()
  File "python_scripts/emf_decrypter.py", line 19, in main
    v = EMFVolume(p, device_infos)
  File "/Users/macmini/iphone-dataprotection/python_scripts/hfs/emf.py", line 120, in __init__
    self.keybag = loadKeybagFromVolume(self, device_infos)
  File "/Users/macmini/iphone-dataprotection/python_scripts/util/bruteforce.py", line 31, in loadKeybagFromVolume
    keybag.setDKey(device_infos)
AttributeError: 'NoneType' object has no attribute 'setDKey'

What version of the product are you using? On what operating system?
OS X version : OS X 10.9.3
XCode version : XCod 5.1.1
Tools revision : run the "hg id" command in the iphone-dataprotection
folder
3cdc9a532c6b+ tip

Please provide any additional information below.
Device: iPhone3,2 running ios7 and complex passcode was setted.

Original issue reported on code.google.com by [email protected] on 29 May 2014 at 8:26

[GoogleCodeExporter]

Sorry. The emf_decrypter is OK. I make a mistake.

Original comment by [email protected] on 30 May 2014 at 8:25