I'm in trouble right now.

I used Disk Utility to create a sparse image and I cannot remember the password, when I created the file I didn't select to remember in keychain.

Now, I try to enter the possible value but it doesn't work. Is there any recommend way to crack the password or give some hint or some app that might be worked on this stuff.

I really need to use the data in that file.

5 Answers 5


CrowBar is somewhat out-of-date.

Probably the most comprehensive and up-to-date free password-recovery package is JohnTheRipper. Among many other formats, it can test .dmg's as well.

Note that JtR does not "break" the encryption, it just automates and speeds the process of trying thousands (or millions, or trillions) of dictionary-based and random passwords in hopes of eventually hitting the correct one that decrypts your data.

JohnTheRipper is a command-line tool and requires one to be pretty well-versed in standard shell syntax, etc.

If you don't want to compile JtR yourself, there are also free unofficial pre-compiled Mac OS X binaries available.

The latest "jumbo" and "magnum" community-contributed versions can handle .dmg files, sparse-images through OS X 10.7. If you dig around in the recent patches you can even find code to handle OS X 10.8 passwords.


Nope, with the strong encryption that Apple uses, if you lose the password, you are out of luck.

  • But try to guess wil not harmful to my file, right?
    – user40436
    Commented Jan 26, 2013 at 14:36
  • Right, You can guess as much as you want and the file will be fine.
    – Ɱark Ƭ
    Commented Jan 26, 2013 at 14:40

It depends on the quality of your password, the quality of your dictionary, your time and cpu power ... https://www.georgestarcher.com/?p=228 or Spartan google helps.

  • Hi, i cannot open crowbarDMG-v1.0.dmg, it said that "The following disk cannot be opened" and the reason is not recognized. Any suggestion??
    – user40436
    Commented Jan 26, 2013 at 15:38
  • It opened ok for me, maybe you got a corrupted download? The file size I got (for the .dmg) is 1,753,195 bytes, and its md5 hash is 49e1a8dc0b74d04eb06db26ade25bc26. Commented Jan 26, 2013 at 17:33

I found this in my own search.. hope it helps. http://crucialsecurityblog.harris.com/2011/03/30/4/

"Crack and Image a FileVault Sparsebundle"


"Encryption: DriveSavers engineers have been trained and certified by leading encryption vendors, such as GuardianEdge, Utimaco Safeguard, PGP and PointSec, to safely recover file-level and disk-level encrypted data" http://www.drivesavers.com/recovery-services/encryption/

  • 2
    From the same web site: "The encryption username, password and/or key must be provided to DriveSavers if this method is chosen". Doesn't look like they are able to crack passwords themselves.
    – nohillside
    Commented Jan 26, 2013 at 20:40

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