How to re-enable internet tethering on 3.1.2 firmware?

With internet tethering enabled you can use iPhone internet connection on you desktop or notebook. Here is a quick tutorial for experienced users. For everybody else - just wait for the new version of PwnageTool or some other utility.

Here it is:

A bsdiff patch to apply to CommCenter in 3.1.2 to re-enable tethering is available here for the 3GS and here for the 3G. It's just a 2-byte patch as shown below (and an appropriate readjusting of the mach-o's codesign hash):

USE THIS AT YOUR OWN RISK! Your carrier may end up charging you for unauthorized tethering access.

Update #1 It looks like a lot of people have been looking at CommCenter lately because IRC user CleanAir had a similar tethering patch. Meanwhile over in the 2G CommCenter, WhiteRat and geniusan have patched in native MMS support for that platform. Kudos to CleanAir, WhiteRat, and geniusan for digging into CommCenter and coming up with patches!

Update #2 A few tutorials have started to pop up. Eventually this will be made a part of the normal PwnageTool flow but for now this is best left for the adventurous users out there!

sub_17538+74   4B F0 58 F8                 BL      validate_signature
sub_17538+74
sub_17538+78   30 B1                       CBZ     R0, FAIL        ; <--- PATCH THIS TO 00 20 (MOV R0,#0)
sub_17538+78
sub_17538+7A   05 20                       MOVS    R0, #5          ; int
sub_17538+7C   1C 49                       LDR     R1, =aValidatedWirel ; "Validated wireless modem connection wit"...
sub_17538+7E   02 9A                       LDR     R2, [SP,#0x24+var_1C]
sub_17538+80   7E F0 00 ED                 BLX     _syslog
sub_17538+80
sub_17538+84
sub_17538+84               loc_175BC                               ; CODE XREF: sub_17538+70j
sub_17538+84   02 9C                       LDR     R4, [SP,#0x24+var_1C]
sub_17538+86   05 E0                       B       loc_175CC
sub_17538+86
sub_17538+88               ; ---------------------------------------------------------------------------
sub_17538+88
sub_17538+88               FAIL                                    ; CODE XREF: sub_17538+78j
sub_17538+88   05 20                       MOVS    R0, #5          ; int
sub_17538+8A   1A 49                       LDR     R1, =aCouldNotValida ; "Could not validate wireless modem conne"...
sub_17538+8C   7E F0 FA EC                 BLX     _syslog
sub_17538+8C

bsdiff patches are the normal way that PwnageTool modifies Apple software. To apply one manually, you must first get the “bspatch” program. Then do:

bspatch CommCenter CommCenter-hacked CommCenter.patch

If you don't have bsdiff but know how to use a hex editor, the differences are available here in text format.

The correct SHA1 of the hacked file will be:

1b19712035f33654cf72838ebe1a2033931b56b2   # 3GS
063165c3fa3e21d30eb4b486fab924ba3ef0ea5e   # 3G

You would then remove the original program and replace it. Don't forget to ensure it has execute permission!

chmod +x /System/Library/PrivateFrameworks/CoreTelephony.framework/Support/CommCenter

After you've started using the hacked CommCenter, visit http://www.benm.at/help/help.php from your iPhone and install a new mobileconfig.

via wikee.iphwn.org