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sendmeamsg

macrumors member
Original poster
May 2, 2010
69
154
I'm one of the few people apparently still rocking the iPhone 4, so this doesn't apply to me and I have no way of testing it, but I have a number of friends who've been complaining that iOS 8 has made their iDevices sluggish and buggy (especially the 4s and iPad 2/3). I found it weird that there was absolutely no way to get around the firmware signing requirements... until I stumbled across this: http://www.saurik.com/id/12

"To this end, I have constructed a server that duplicates the functionality exposed by Apple's signature server, except using "on file" results rather than live requests.
All we need, then, is to make iTunes use it. Luckily, most operating systems also have the ability to locally define bypasses on specific hostnames through a file called hosts. Using this, we can redirect requests to Apple's signature server to Cydia.
So, open the file C:\Windows\System32\drivers\etc\hosts (Windows) or /etc/hosts (Mac OS X) and add the following entry to the bottom of the file.
74.208.10.249 gs.apple.com
Now, when iTunes thinks it is talking to Apple, it is talking to Cydia instead. Doing this will allow iTunes to access signatures already stored by Cydia's "on file" feature.
This server will also act as a cache for any SHSH blobs it hasn't seen, acting as an intermediary to Apple's server. This effectively registers your device with the "on file" mechanism, which means you can now enjoy the protections of being able to downgrade your firmware in the future even if you aren't jailbroken."

I have no way of testing this myself, and your mileage may vary, but from what I can see, it looks like it should work and allow you to downgrade your firmware (to any version, for that matter, not just 7.1.2). I'd love for someone to let me know if it works! Proceed with caution, obviously.

Anyway, hopefully some of you find this useful.
 

bushido

Suspended
Mar 26, 2008
8,070
2,755
Germany
nah thats a old post thats talking about iOS3 ... i think the last iOS that supported the blobs method was iOS5
 

sendmeamsg

macrumors member
Original poster
May 2, 2010
69
154
Another newbie with a breakthrough post:D

Yea, I suppose it was too good to be true. Not to mention the fact that I apparently can't read. Is there a dunce cap I can wear?

Still surprised someone hasn't figured a way around this, though...
 

Snide

macrumors 6502a
Apr 12, 2005
905
737
Now where is that FacePalm video/graphic others have posted in response to threads like this ??

giphy.gif
 

eyoungren

macrumors Penryn
Aug 31, 2011
28,794
26,885
Hey OP, got a way to downgrade from 7.1.2 to iOS 6?

Now THAT would be a breakthrough! :D
 

XboxMySocks

macrumors 68020
Oct 25, 2009
2,230
198
Yea, I suppose it was too good to be true. Not to mention the fact that I apparently can't read. Is there a dunce cap I can wear?

Still surprised someone hasn't figured a way around this, though...

How are you supposed to "figure a way around" a 256bit AES key?
 

eyoungren

macrumors Penryn
Aug 31, 2011
28,794
26,885
Or if we could dual boot to ios and Yosemite.
Someone put up a youtube video of that:D
I was thinking maybe someone could figure out a way we could run MS-DOS 6.0 on an iPhone.

I don't think we'll get any takers for that one though. :p
 

Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,533
At the iPhone hacks section.
Brute force it with your graphics card using oclhashcat or something similar

It's just so simple and easy to do:)

----------

I was thinking maybe someone could figure out a way we could run MS-DOS 6.0 on an iPhone.

I don't think we'll get any takers for that one though. :p

Something like that shouldn't be that hard I would think.
But pretty much pointless :D
 

darricksailo

macrumors 601
Dec 18, 2012
4,353
113
Brute force it with your graphics card using oclhashcat or something similar

You do realize it's realistically impossible to brute force a AES 256bit key in a reasonable amount of time, right?

Even with the super computers we have today can't
 

XboxMySocks

macrumors 68020
Oct 25, 2009
2,230
198
You do realize it's realistically impossible to brute force a AES 256bit key in a reasonable amount of time, right?

Even with the super computers we have today can't

If I recall correctly the best supercomputer we have would need about 2 weeks to crack it.

However, it costs something like $500.000 :)
 

darricksailo

macrumors 601
Dec 18, 2012
4,353
113
If I recall correctly the best supercomputer we have would need about 2 weeks to crack it.

However, it costs something like $500.000 :)

I'm not an expert about encryption by any means but I do remember reading an article and hearing from somewhere that it would take longer than the age of the universe to crack, even with a super computer (assuming we're not using some new method of cracking AES encryption)

I never did look too much into it though so not quite sure if what I heard was correct or not
 

Wowzera

macrumors 6502a
Oct 14, 2008
857
28
Brazil
I'm not an expert about encryption by any means but I do remember reading an article and hearing from somewhere that it would take longer than the age of the universe to crack, even with a super computer (assuming we're not using some new method of cracking AES encryption)

I never did look too much into it though so not quite sure if what I heard was correct or not

"AES permits the use of 256-bit keys. Breaking a symmetric 256-bit key by brute force requires 2128 times more computational power than a 128-bit key. 50 supercomputers that could check a billion billion (1018) AES keys per second (if such a device could ever be made) would, in theory, require about 3×1051 years to exhaust the 256-bit key space."
 

Applejuiced

macrumors Westmere
Apr 16, 2008
40,672
6,533
At the iPhone hacks section.
I'm not an expert about encryption by any means but I do remember reading an article and hearing from somewhere that it would take longer than the age of the universe to crack, even with a super computer (assuming we're not using some new method of cracking AES encryption)

I never did look too much into it though so not quite sure if what I heard was correct or not

Correct.
I heard it could take something like 80-100 years even with today computer tech to crack it.
 
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