So, after releasing the iPhone 5S Setup.app Patch, I decided to make the CFW creation tutorial as people demanded it in the comments section. This video shows exactly what you need to do and what tools you got to use in order to combine iOS 9.2.1 from iPhone 5,1 (the ROOT FS) with the iOS 9.3.1 for iPhone 5S for NAND Attack on LibiMobileDevice.
The NAND Brute Force Attack method is harder to perform and requires practice and patience, but it is the best thing you can try for iCloud issue on these devices.
Creation of the CFW modified (patched Setup.app) requires the proper AES keys, this is why we combine the IPSWs.
I managed to successfully bypass iPhone 5 (16 GB) (Black) using this method. You can see it here as well as the proofs:
Patched Setup.app for 5S: https://www.youtube.com/watch?v=7lXJqVDcGyY
How to bypass iPhone 4S and 5C: https://youtu.be/gQv-PPI7-Yk
How to bypass iPhone 5: https://www.youtube.com/watch?v=hSCFo3cghV4
How to exit Recovery Mode: https://www.youtube.com/watch?v=SMuy5ZjUpJ8
P.S. I can upload my CFW if someone can't follow the tutorial; For that you need to show support for this development by giving a Like to the video, and you need to be patient , as the tutorial is posted because uploading a lot of gigabytes isn't that effective.
Plist Editor: http://www.icopybot.com/plist-editor.htm
Firmware Manager: https://www.theiphonewiki.com/wiki/F.C.E._365_Firmware_Manager
P.S. OSX is required for this method! You can use either a MAC or a virtual OSX in Virtual BOX (on Windows).
The keys page: https://www.theiphonewiki.com/wiki/Firmware
If you get "Waiting for Device" Error try: https://www.youtube.com/watch?v=xGwKqzh9270
A second method to restore: https://www.youtube.com/watch?v=xjT1b9PhRwk
ASR Error 110 fix: https://www.youtube.com/watch?v=9b9_rAnCNVE
If you have any other question, leave them in the comment section down bellow! I will do my best to answer all!
WORK IN PROGRESS! (CAN BE TRIED)!
This is the very first time someone tries to bypass iPhone 5S, and of course there are a lot of development and cleanup to be done, but it is as far as you can go for the moment on an iPhone 5S. If people like this video and show appreciation, I might continue developing for 5S and up, if not, I will stick to x32 devices only.
Compared with the first time I tried to restore an iPhone 5S CFW, I made a huge project by locating a new file that has to be edited and the restore goes further, It still remains a work in progress, but if people support the project, we might proceed!
Don't forget to Like, Share and Subscribe, it helps to continue the development!
USAGE FOR STOLEN DEVICES IS STRICTLY PROHIBITED! THIS WON'T WORK FOR LOST / STOLEN DEVICES!
THIS IS A WORK IN PROGRESS!