iOS 7 Tethered Downgrade

First Steps

Most tools are designed to be used on macOS, however if compiled from source they may be able to run on other operating systems.

Download and compile:

img4lib (img4) by @xerub

dmgtool from xpwn by @planetbeing

img4tool by @Tihmstar

iPatcher by @exploit3dguy

tsschecker by @Tihmstar

seprmvr64lite by @mineekdev

irecovery from Libimobiledevice

usbmuxd from Libimobiledevice

kerneldiff by @dedbeddedbed

Download (precompiled):

iPwnder by @dora2ios

gnu-tar from homebrew

You may also want an SFTP client. I recommend Cyberduck

Other:

Jailbroken A7 device on latest iOS with openssh installed (any compatible jailbreak should work)

The target firmware (iOS 7.x) which can be found here

You will also need to download an iOS 8.0 IPSW to make an SSH ramdisk

NOTE: Due to Apple messing up their servers, you may need to download the IPSW using http. To do this, remove "secure-" from the URL and replace "https" with "http"

SHSH(2) (apticket) files:

SHSH signatures are required in order to properly build img4 files that the BootROM will accept from pwned DFU mode. Unless you have them already, you can save them with tsschecker (or other public tools.)

NOTE: SHSH version does not have to match target iOS version.

tsschecker -d iPhoneX,X -l -e ECID -B boardconfig -l -s

If you do not know your ECID or boardconfig, connect the device in recovery mode and execute:

irecovery -q

which will give output similar to this:



Next, convert your saved shsh2 file for your device to raw IM4M with img4tool. This file will be critical for signing components later on:

img4tool -e -s *.shsh2 -m IM4M

Next part → Preparations

iOS 7 Tethered Downgrade