Utility to extract and repack Android backups created with adb backup (ICS+). Largely based on BackupManagerService.java from AOSP.

Usage:

Download the latest version of Bouncy Castle Provider jar (bcprov-jdk15on-148.jar) from here:

http://www.bouncycastle.org/latest_releases.html

Drop the latest Bouncy Castle jar in lib/, import in Eclipse and adjust build path if necessary. Use the abe.sh script to start the utility. Syntax:

unpack:	abe.sh unpack <backup.ab> <backup.tar> [password]
pack:	abe.sh pack <backup.tar> <backup.ab> [password]

If you don't specify a password the backup archive won't be encrypted but only compressed.

Alternatively:

Use the bundled Ant script to create an all-in-one jar and run with: (you still need to put the Bouncy Castle jar in lib/)

java -jar abe.jar pack|unpack [parameters as above]

(Thanks to Jan Peter Stotz for contributing the build.xml file)

More details about the backup format and the tool implementation in the associated blog post:

http://nelenkov.blogspot.com/2012/06/unpacking-android-backups.html