DevTeam worked hard for the last several hours and released jailbreak tool for iOS 4.2.1. It is redsn0w 0.9.6 b4.
As usual we remind all ultrasn0w unlockers please stay away from this official firmware. Wait for the ability to create custom 4.2.1 IPSWs that don’t update your baseband!
New redsn0w 0.9.6 b4 uses limera1n exploit and will successfully jailbreak all devices. The only problem is that it is a tethered jailbreak, which means you will have to plug it to a computer and rerun redsn0w on every reboot. This so called tethered or semi-tethered jailbreak. This condition applies to iPhone 3GS (new bootrom), iPhone 4, iPad, iPod touch 2G (MC model), iPod touch 3G and iPod touch 4G. Hackers are working hard to create untethered jailbreak for these devices. To use future untethered jailbreak you need to save SHSH keys for iOS 4.1 using TinyUmbrella utility or directly in Cydia.
Old devices like iPhone 3GS (old bootrom), iPhone 3G and iPod touch 2G (non-MC model) can be jailbroken-untethered right now using this latest version of RedSn0w.
You cannot use JailBreakMe method to jailbreak and unlock iOS 4.0.2 on iPhone 3G. However you can still jailbreak and unlock iPhone 3G using redsn0w. Here are the instructions:
Run RedSn0w and point it at the 4.0 IPSW. (Yes – point it at the 4.0 IPSW even though you’re at 4.0.2). This will also hacktivate your iPhone3G at 4.0.1 if you haven’t already been activated by iTunes.
If you need a carrier unlock – install ultrasn0w in Cydia (add repository http://repo666.ultrasn0w.com). For T-Mobile in the USA remember to turn off 3G mode in Settings→General→Network.
Can not wait for the official release? Do you want to get CineXPlayer for iPad on your iPhone and iPod touch right now? For those of you who do not know, CineXPlayer is an iPad application that allows you to download Xvid AVI files using iTunes, so you can easily reproduce the format that Apple won’t. Because the developer has not invented version of the application for the iPhone, the hacker decided to do everything by himself.
It is a complete step by step tutorial on how to install it on your iPhone or iPod touch available here. You just need to jailbreak these devices, because the process involves SSH (SSH program for secure file sharing on the network) to access the iPhone, but it’s worth it if you want to get it right now!
Go to /private/var/root/Library/, delete original lockdown folder and put this lockdown folder after you extract it from the zip file
Restart phone
If you are not jailbroken:
Sherif Hashim discovered that you can activate your iPhone 4, iPhone 3GS or even iPhone 3G without the original carrier SIM card. You need a “phonebook sim card” or 02 simcard. You can buy these type of sim at radioshack, bestbuy or other mobile electronics store (for example here).
Once you get passed the Emergency Call screen, connect to Wifi, jailbreak using JailbreakMe.com and unlock using ultrasn0w. Once that is complete you should be passed activation and unlocked (able to use any sim). If you get a different simcard error, do the following final step:
Go to /private/var/root/Library/, delete original lockdown folder and put this lockdown folder after you extract it from the zip file
Restart phone
If you have itunes invalid response problem:
Connect to wifi and ssh to your phone (via winscp, putty, terminal, etc).
Navigate to your lockdown folder (/private/var/root/Library/).
Delete pair_records folder
Reconnect the cable and see that your invalid response problem is gone.
If you bought your iPhone 4 on ebay you will need the official sim (at&t) or a universal sim, like ones you can grab at bestbuy for $10 this will get you passed Emergency Screen.
MuscleNerd tweeted today that the recent redsn0w utility is able to jailbreak the iOS 4.1 beta2 on iPhone 3G and iPod Touch 2G. This is useful for developers only, however good news for everyone.
Here’s some info from the DevTeam wiki page:
If you’ve updated to 4.1beta2 on iPhone3G or iPod2G(non-MC), you can use this redsn0w from June to jailbreak. Just point it at the 4.0 IPSW (the public one, not the developer GM one).
(Yes – point it at the 4.0 IPSW even though you’re at 4.1beta2).
Don’t do this if you need the ultrasn0w carrier unlock!!
Note 1: This won’t hacktivate your iPhone3G – but for those with legit access to the 4.1beta2 this shouldn’t matter. Please don’t pirate Apple software
Note 2: If you’re at 4.1beta2 you’ll probably experience network problems after jailbreaking. Until a new version of redsn0w is released, you may need to rely on afc2 access (such as FunBox-like file browser programs) to manipulate your filesystem.
Note 3: This is recommended only for power users who can deal with the problems that will pop up as the JB apps fall further behind the beta firmwares.