Pascal Pascal - 5 months ago 90
iOS Question

IOS Jailbreak How do intercept SMS / Text Messages

I'm currently trying to write an application that intercepts text messages and reacts depending on the content of that message.
I tried to hook into

_receivedMessage:(struct __CKSMSRecord *)message replace:(BOOL)replace
method in the CKSMSService class but this seems not do get called at all.

Could someone please tell me what function/class i have to hook in? I need to intercept the text message before it gets displayed and stored into the database. I'm on IOS 5.0.1.

Any help is truly appreciated.

Answer

This code snippet should intercept SMS messages- You can extend it for other kinds of notifications. Will work on iOS 5.0.1 as well. Does not work with iMessages though. Link with CoreTelephony framework (there are bunch of private headers there which you'd can class-dump)

#include <dlfcn.h>

#define CORETELPATH "/System/Library/PrivateFrameworks/CoreTelephony.framework/CoreTelephony"
id(*CTTelephonyCenterGetDefault)();

void (*CTTelephonyCenterAddObserver) (id,id,CFNotificationCallback,NSString*,void*,int);


static void telephonyEventCallback(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo)
{
    NSString *notifyname=(NSString *)name;
    if ([notifyname isEqualToString:@"kCTMessageReceivedNotification"])//received SMS
    {
        NSLog(@" SMS Notification Received :kCTMessageReceivedNotification");
        // Do blocking here. 
    }
}

-(void) registerCallback {

 void *handle = dlopen(CORETELPATH, RTLD_LAZY);
    CTTelephonyCenterGetDefault = dlsym(handle, "CTTelephonyCenterGetDefault");
    CTTelephonyCenterAddObserver = dlsym(handle,"CTTelephonyCenterAddObserver");
    dlclose(handle);
    id ct = CTTelephonyCenterGetDefault();

    CTTelephonyCenterAddObserver(
                                 ct, 
                                 NULL, 
                                 telephonyEventCallback,
                                 NULL,
                                 NULL,
                                 CFNotificationSuspensionBehaviorDeliverImmediately);
}