This document contains code snippets to check if a device is jailbroken using several techniques: checking for the existence of files and folders associated with jailbreaking like Cydia.app or /private/var/lib/apt/; checking if the stat function has been hooked by comparing the library it points to; checking if the MobileSubstrate dylib is loaded; checking the DYLD_INSERT_LIBRARIES environment variable. If any of the checks return true, it is determined that the device is jailbroken.

3. Storehouse

4. //check cydia
NSString *cydiaPath = @"/Applications/Cydia.app";
if ([[NSFileManager defaultManager] fileExistsAtPath:cydiaPath]){
return YES;
}
NSURL* url = [NSURL URLWithString:@"cydia://package/
com.example.package"];
if ([[UIApplication sharedApplication] canOpenURL:url]) {
return YES;
}

5. //check cydia
let cydiaPath = "/Applications/Cydia.app"
if(NSFileManager.defaultManager().fileExistsAtPath(cydiaPath)){
//device is jail break
}
let url = NSURL.URLWithString("cydia://package/
com.example.package")
let app = UIApplication.sharedApplication()
if (app.canOpenURL(url)){
//device is jail break
}

7. #import <sys/stat.h>
struct stat stat_info;
if (0 == stat("/Applications/Cydia.app", &stat_info)) {
//device is jail break
}
//check JailBreak generate Data Structure
if (0 == stat("/private/var/lib/apt/", &stat_info)) {
//device is jail break
}
if (0 == stat("/User/Applications/", &stat_info)) {
//device is jail break
}

9. #import <dlfcn.h>
#if !TARGET_IPHONE_SIMULATOR
//check hook stat
int ret ;
Dl_info dylib_info;
int (*func_stat)(const char *, struct stat *) = stat;
if ((ret = dladdr(func_stat, &dylib_info))) {
NSLog(@"lib :%s", dylib_info.dli_fname);
char* kernal = "/usr/lib/system/libsystem_kernel.dylib";
if (strcmp(dylib_info.dli_fname,kernal)!=0) {
//device is jail break
//Let it go
}
}
#endif

10. /System/Library/Frameworks/CoreGraphics.framework/CoreGraphics
/System/Library/Frameworks/UIKit.framework/UIKit
/System/Library/Frameworks/Foundation.framework/Foundation
/usr/lib/libobjc.A.dylib
/usr/lib/libSystem.B.dylib
/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation
/usr/lib/libz.1.dylib
/System/Library/Frameworks/Accelerate.framework/Accelerate
/usr/lib/libc++.1.dylib
……
/usr/lib/system/libsystem_info.dylib
/usr/lib/system/libsystem_kernel.dylib
/usr/lib/system/libsystem_m.dylib
/usr/lib/system/libsystem_malloc.dylib
/usr/lib/system/libsystem_network.dylib
/usr/lib/system/libsystem_notify.dylib
/usr/lib/system/libsystem_platform.dylib
/usr/lib/system/libsystem_pthread.dylib

11. #import <mach-o/dyld.h>
uint32_t count = _dyld_image_count();
for (uint32_t i = 0 ; i < count; ++i) {
char* substrate = “Library/MobileSubstrate/MobileSubstrate.dylib";
//NSLog(@“%s",_dyld_get_image_name(i));
if (strcmp(_dyld_get_image_name(i),substrate)==0) {
return YES;
}
}

12. #import <mach-o/dyld.h>
uint32_t count = _dyld_image_count();
for (uint32_t i = 0 ; i < count; ++i) {
char* substrate = “Library/MobileSubstrate/MobileSubstrate.dylib";
//NSLog(@“%s",_dyld_get_image_name(i));
if (strcmp(_dyld_get_image_name(i),substrate)==0) {
return YES;
}
}
If naming is not MobileSubstrate.dylib

13. #if !TARGET_IPHONE_SIMULATOR
char *env = getenv("DYLD_INSERT_LIBRARIES");
if (env) {
//device is jailbreak
}
#endif

15. - (void)viewDidLoad {
[super viewDidLoad];
if ([self isJailBreakCheck]) {
self.statusLabel.text = @"You're Jailbreak”;
//replace rooViewController.view when found JB
}
else{
self.statusLabel.text = @"You're not Jailbreak";
}
}