Firmware Keys

VFDecrypt Keys are the keys which can decrypt the files that come with the firmware. Apple uses a public-private key encryption to ensure the safety of their files. Over time Apple has changed the way to encrypt firmware files, thus the way to decrypt files as well as the way to get the VFDecrypt Keys has also.

IMG2 was the file format used prior to iOS 2.0. For iOS 1.1.x, IMG2 files were encrypted with Key 0x837.

IMG3 encrypted files contain encrypted versions of the VFDecrypt Keys as part of the KBAG (key bag). These can be decrypted with the GID-key. For jailbroken iDevices the VFDecrypt keys can be retrieved with the devices hardware AES engine. The VFDecrypt key for the root filesystem image of an iDevice (~500 MB to 800MB in the case of iOS 5) requires either a decrypted Restore Ramdisk or Update Ramdisk. Once you have a decrypted Restore or Update Ramdisk, GenPass can be used to gather the keys for the root filesystem. For the root filesystem there is one key per device model, with no IV. You can mount this once it has been decrypted using your program of choice. (For example, 7-zip on Windows (after extracting the DMG on Windows, extract the biggest file with 7-Zip)

Gaps
As you will notice, there may be a gap or two, or a key for a current build that is not there. Please feel free to add them, but please be sure that it is only the key for a User or Developer build, as if you gave the key for another type of build that might or may not be out there people could get in trouble, and we do not want that. Thanks for contributing!