1.目标
此篇文本为入门文章，大家莫抱过多期望。此文章的目的是教大家如何从UI入手，去定位自己想要的东西。
2.操作环境
-
mac系统
-
frida-ios-dump：砸壳
-
已越狱iOS设备：脱壳及frida调试
-
IDA Pro：静态分析
3.流程
寻找切入点
启动App后，界面如下图：
分析过程
从界面可以看出，App检测到越狱后，会弹出一个弹窗，文案为越狱手机存在安全风险，做iOS开发的都知道，最终这文案显示前，会调用UILabel类的setText:方法。我们trace该方法并打印堆栈:
js代码：
{
onEnter(log, args, state) {
log(`-[UILabel setText:${new ObjC.Object(args[2])}]`);
log('UILabel setText called from:\n' +
Thread.backtrace(this.context, Backtracer.ACCURATE)
.map(DebugSymbol.fromAddress).join('\n') + '\n');
},
onLeave(log, retval, state) {
}
}
关键日志如下：
-[UILabel setText:越狱手机存在安全风险]
UILabel setText called from:
0x1eaa7d0f4 UIKitCore!-[_UIAlertControllerView _updateMessageLabelContents]
0x1eaa756f8 UIKitCore!-[_UIAlertControllerView _prepareMesssageLabel]
0x1eaa750f8 UIKitCore!-[_UIAlertControllerView _prepareViewsAndAddConstraints]
0x1eaa75048 UIKitCore!-[_UIAlertControllerView setAlertController:]
0x1eaa61740 UIKitCore!-[UIAlertController loadView]
0x1ead35ed8 UIKitCore!-[UIViewController loadViewIfRequired]
0x1ead36628 UIKitCore!-[UIViewController view]
0x1ead4ddd4 UIKitCore!-[UIViewController _setPresentationController:]
0x1ead461f4 UIKitCore!-[UIViewController _presentViewController:modalSourceViewController:presentationController:animationController:interactionController:completion:]
0x1ead47ccc UIKitCore!-[UIViewController _presentViewController:withAnimationController:completion:]
0x1ead4a3a8 UIKitCore!__63-[UIViewController _presentViewController:animated:completion:]_block_invoke
0x1ead4a8a4 UIKitCore!-[UIViewController _performCoordinatedPresentOrDismiss:animated:]
0x1ead4a300 UIKitCore!-[UIViewController _presentViewController:animated:completion:]
0x1ead4a560 UIKitCore!-[UIViewController presentViewController:animated:completion:]
0x10128253c App!0xd253c (0x1000d253c)
0x1be344a38 libdispatch.dylib!_dispatch_call_block_and_release
使用frida-ios-dump砸壳后，再使用IDA Pro编译ipa文件。
跳转到内存0x1000d253c位置
再按F5:
__int64 __fastcall sub_1000D24D4(_QWORD *a1)
{
void *v1; // x19
__int64 v2; // x20
void **v4; // [xsp+8h] [xbp-38h]
__int64 v5; // [xsp+10h] [xbp-30h]
__int64 (__fastcall *v6)(); // [xsp+18h] [xbp-28h]
void *v7; // [xsp+20h] [xbp-20h]
__int64 v8; // [xsp+28h] [xbp-18h]
v1 = (void *)a1[4];
v2 = a1[5];
v4 = _NSConcreteStackBlock;
v5 = 3254779904LL;
v6 = sub_1000D2554;
v7 = &unk_101A29970;
v8 = objc_retain(a1[6]);
objc_msgSend(v1, "presentViewController:animated:completion:", v2, 1LL, &v4);
return objc_release(v8);
}
查找sub_1000D24D4函数的交叉引用，一层一层往上找，最终找到如下函数：
void __cdecl -[UIViewController cft_presentViewController:presentType:presentCompletionHandler:dismissCompleteHandler:](UIViewController *self, SEL a2, id a3, unsigned __int64 a4, id a5, id a6)
{
id v6; // x21
id v7; // x20
UIViewController *v8; // x24
void *v9; // x19
__int64 v10; // x20
__int64 v11; // x21
void *v12; // x0
__int64 v13; // x22
dispatch_semaphore_t v14; // x23
void *v15; // x0
void *v16; // x24
void *v17; // x0
void *v18; // x0
void *v19; // x27
void *v20; // x0
__int64 v21; // x28
void *v22; // x0
void *v23; // x0
void *v24; // x25
void *v25; // x0
__int64 v26; // x26
__int64 v27; // [xsp+8h] [xbp-A8h]
void **v28; // [xsp+10h] [xbp-A0h]
__int64 v29; // [xsp+18h] [xbp-98h]
__int64 (__fastcall *v30)(__int64); // [xsp+20h] [xbp-90h]
void *v31; // [xsp+28h] [xbp-88h]
__int64 v32; // [xsp+30h] [xbp-80h]
__int64 v33; // [xsp+38h] [xbp-78h]
__int64 v34; // [xsp+40h] [xbp-70h]
UIViewController *v35; // [xsp+48h] [xbp-68h]
__int64 v36; // [xsp+50h] [xbp-60h]
__int64 v37; // [xsp+58h] [xbp-58h]
v6 = a6;
v7 = a5;
v8 = self;
v9 = (void *)objc_retain(a3);
v10 = objc_retain(v7);
v11 = objc_retain(v6);
v37 = 0LL;
v12 = objc_msgSend(
v9,
"aspect_hookSelector:withOptions:usingBlock:error:",
"viewDidDisappear:",
0LL,
&off_101A2BF98,
&v37);
objc_unsafeClaimAutoreleasedReturnValue(v12);
v13 = objc_retain(v37);
if ( !v13 )
{
v14 = dispatch_semaphore_create(0LL);
v28 = _NSConcreteStackBlock;
v29 = 3254779904LL;
v30 = sub_1000D23A0;
v31 = &unk_101A2BFB8;
v32 = objc_retain(v9);
v33 = objc_retain(v11);
v27 = objc_retain(v14);
v34 = v27;
v35 = v8;
v36 = objc_retain(v10);
v15 = objc_msgSend(&OBJC_CLASS___NSBlockOperation, "blockOperationWithBlock:", &v28);
v16 = (void *)objc_retainAutoreleasedReturnValue(v15);
v17 = objc_msgSend((void *)qword_101F71BF8, "operations");
v18 = (void *)objc_retainAutoreleasedReturnValue(v17);
v19 = v18;
v20 = objc_msgSend(v18, "lastObject");
v21 = objc_retainAutoreleasedReturnValue(v20);
objc_release(v21);
objc_release(v19);
if ( v21 )
{
v22 = objc_msgSend((void *)qword_101F71BF8, "operations");
v23 = (void *)objc_retainAutoreleasedReturnValue(v22);
v24 = v23;
v25 = objc_msgSend(v23, "lastObject");
v26 = objc_retainAutoreleasedReturnValue(v25);
objc_msgSend(v16, "addDependency:", v26);
objc_release(v26);
objc_release(v24);
}
objc_msgSend((void *)qword_101F71BF8, "addOperation:", v16);
objc_release(v16);
objc_release(v36);
objc_release(v34);
objc_release(v33);
objc_release(v32);
objc_release(v27);
}
objc_release(v13);
objc_release(v11);
objc_release(v10);
objc_release(v9);
}
接下来，同时跟踪UILabel的setText:方法和UIViewController的XXX_presentViewController:presentType:presentCompletionHandler:dismissCompleteHandler:方法，获取到日志如下：
-[UIViewController cft_presentViewController:0x104928e00 presentType:0x1 presentCompletionHandler:0x16ec4e5a8 dismissCompleteHandler:0x16ec4e580]
UIViewController cft_presentViewController called from:
0x1012b9fdc App!+[CFTAlertPresentController presentAlertController:presentCompletionHandler:dismissCompleteHandler:]
0x1012d464c App!-[LaunchingViewController start]
0x1012d3360 App!0x123360 (0x100123360)
0x1be3457d4 libdispatch.dylib!_dispatch_client_callout
0x1be2f3c1c libdispatch.dylib!_dispatch_lane_barrier_sync_invoke_and_complete
0x1012d3310 App!0x123310 (0x100123310)
0x1012b9978 App!0x109978 (0x100109978)
0x1eb76ad1c UIKitCore!-[UIViewAnimationBlockDelegate _didEndBlockAnimation:finished:context:]
0x1eb741a74 UIKitCore!-[UIViewAnimationState sendDelegateAnimationDidStop:finished:]
0x1eb742048 UIKitCore!-[UIViewAnimationState animationDidStop:finished:]
0x1c2e573c8 QuartzCore!CA::Layer::run_animation_callbacks(void*)
0x1be3457d4 libdispatch.dylib!_dispatch_client_callout
0x1be2f3008 libdispatch.dylib!_dispatch_main_queue_callback_4CF$VARIANT$mp
0x1be898b20 CoreFoundation!__CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__
0x1be893a58 CoreFoundation!__CFRunLoopRun
0x1be892fb4 CoreFoundation!CFRunLoopRunSpecific
-[UILabel setText:您的设备不安全]
UILabel setText called from:
0x1eaa7cfe8 UIKitCore!-[_UIAlertControllerView _updateTitleLabelContents]
0x1eaa75544 UIKitCore!-[_UIAlertControllerView _prepareTitleLabel]
0x1eaa750e8 UIKitCore!-[_UIAlertControllerView _prepareViewsAndAddConstraints]
0x1eaa75048 UIKitCore!-[_UIAlertControllerView setAlertController:]
0x1eaa61740 UIKitCore!-[UIAlertController loadView]
0x1ead35ed8 UIKitCore!-[UIViewController loadViewIfRequired]
0x1ead36628 UIKitCore!-[UIViewController view]
0x1ead4ddd4 UIKitCore!-[UIViewController _setPresentationController:]
0x1ead461f4 UIKitCore!-[UIViewController _presentViewController:modalSourceViewController:presentationController:animationController:interactionController:completion:]
0x1ead47ccc UIKitCore!-[UIViewController _presentViewController:withAnimationController:completion:]
0x1ead4a3a8 UIKitCore!__63-[UIViewController _presentViewController:animated:completion:]_block_invoke
0x1ead4a8a4 UIKitCore!-[UIViewController _performCoordinatedPresentOrDismiss:animated:]
0x1ead4a300 UIKitCore!-[UIViewController _presentViewController:animated:completion:]
0x1ead4a560 UIKitCore!-[UIViewController presentViewController:animated:completion:]
0x10128253c App!0xd253c (0x1000d253c)
0x1be344a38 libdispatch.dylib!_dispatch_call_block_and_release
-[UILabel setText:越狱手机存在安全风险]
UILabel setText called from:
0x1eaa7d0f4 UIKitCore!-[_UIAlertControllerView _updateMessageLabelContents]
0x1eaa756f8 UIKitCore!-[_UIAlertControllerView _prepareMesssageLabel]
0x1eaa750f8 UIKitCore!-[_UIAlertControllerView _prepareViewsAndAddConstraints]
0x1eaa75048 UIKitCore!-[_UIAlertControllerView setAlertController:]
0x1eaa61740 UIKitCore!-[UIAlertController loadView]
0x1ead35ed8 UIKitCore!-[UIViewController loadViewIfRequired]
0x1ead36628 UIKitCore!-[UIViewController view]
0x1ead4ddd4 UIKitCore!-[UIViewController _setPresentationController:]
0x1ead461f4 UIKitCore!-[UIViewController _presentViewController:modalSourceViewController:presentationController:animationController:interactionController:completion:]
0x1ead47ccc UIKitCore!-[UIViewController _presentViewController:withAnimationController:completion:]
0x1ead4a3a8 UIKitCore!__63-[UIViewController _presentViewController:animated:completion:]_block_invoke
0x1ead4a8a4 UIKitCore!-[UIViewController _performCoordinatedPresentOrDismiss:animated:]
0x1ead4a300 UIKitCore!-[UIViewController _presentViewController:animated:completion:]
0x1ead4a560 UIKitCore!-[UIViewController presentViewController:animated:completion:]
0x10128253c App!0xd253c (0x1000d253c)
0x1be344a38 libdispatch.dylib!_dispatch_call_block_and_release
在XXX_presentViewController:presentType:presentCompletionHandler:dismissCompleteHandler:方法的调用栈，发现[LaunchingViewController start]方法，使用ida pro查看该函数：
void __cdecl -[LaunchingViewController start](LaunchingViewController *self, SEL a2)
{
if ( !(~LODWORD(self->_launchAchieveOption) & 0x1FLL) )
{
v2 = self;
self->_launchAchieveOption = 0LL;
v3 = ((id (__cdecl *)(GuaTabBarController_meta *, SEL))objc_msgSend)(
(GuaTabBarController_meta *)&OBJC_CLASS___GuaTabBarController,
"shareTabBarController");
v4 = objc_retainAutoreleasedReturnValue(v3);
v23 = _NSConcreteStackBlock;
v24 = 3254779904LL;
v25 = sub_100124684;
v26 = &unk_101A2BC20;
v5 = (void *)objc_retain(v4);
v27 = v5;
v28 = v2;
+[NaviService naviModelWithNaviRoot:withNaviHead:withSourceFrom:ret:](
&OBJC_CLASS___NaviService,
"naviModelWithNaviRoot:withNaviHead:withSourceFrom:ret:",
_NSConcreteStackBlock,
3254779904LL,
sub_100124684,
&unk_101A2BC20);
if ( v2->_adDetailDisplayController )
{
v6 = objc_msgSend(v5, "viewControllers", v23, v24, v25, v26);
v7 = (void *)objc_retainAutoreleasedReturnValue(v6);
v8 = v7;
v9 = objc_msgSend(v7, "objectAtIndexedSubscript:", 0LL, v23, v24, v25, v26);
v10 = (void *)objc_retainAutoreleasedReturnValue(v9);
objc_msgSend(v10, "pushViewController:animated:", v2->_adDetailDisplayController, 1LL, v23, v24, v25, v26);
}
v11 = objc_msgSend(&OBJC_CLASS___UIApplication, "sharedApplication", v23, v24, v25, v26);
v12 = (void *)objc_retainAutoreleasedReturnValue(v11);
v13 = v12;
v14 = objc_msgSend(v12, "delegate", v23, v24, v25, v26);
v15 = (void *)objc_retainAutoreleasedReturnValue(v14);
v16 = v15;
v17 = objc_msgSend(v15, "window", v23, v24, v25, v26);
v18 = (void *)objc_retainAutoreleasedReturnValue(v17);
objc_msgSend(v18, "setRootViewController:", v5, v23, v24, v25, v26);
if ( (unsigned int)+[XXXJailBreakJudge deviceIsJailBreak](
&OBJC_CLASS___XXXJailBreakJudge,
"deviceIsJailBreak",
v23,
v24,
v25,
v26) )
{
v19 = objc_msgSend(
&OBJC_CLASS___UIAlertController,
"alertControllerWithTitle:message:preferredStyle:",
CFSTR("您的设备不安全"),
CFSTR("越狱手机存在安全风险"),
1LL,
v23,
v24,
v25,
v26);
v20 = (void *)objc_retainAutoreleasedReturnValue(v19);
v21 = objc_msgSend(
&OBJC_CLASS___UIAlertAction,
"actionWithTitle:style:handler:",
CFSTR("确定"),
0LL,
0LL,
v23,
v24,
v25,
v26);
v22 = objc_retainAutoreleasedReturnValue(v21);
objc_msgSend(v20, "addAction:", v22, v23, v24, v25, v26);
+[XXXAlertPresentController presentAlertController:](
&OBJC_CLASS___XXXAlertPresentController,
"presentAlertController:",
v20,
v23,
v24,
v25,
v26);
}
}
}
从函数中可发现越狱检测函数为[XXXJailBreakJudge deviceIsJailBreak]：
bool __cdecl +[CFTJailBreakJudge deviceIsJailBreak](CFTJailBreakJudge_meta *self, SEL a2)
{
CFTJailBreakJudge_meta *v2; // x20
void *v3; // x0
__int64 v4; // x0
void *v5; // x0
void *v6; // x19
void *v7; // x0
void *v8; // x22
__int64 v9; // x25
unsigned __int64 v10; // x26
uint32_t v11; // w0
uint32_t v12; // w20
uint32_t v13; // w21
void *v14; // x25
const char *v15; // x0
void *v16; // x25
char v17; // w26
_BOOL8 v18; // x20
bool result; // w0
__int128 v20; // [xsp+0h] [xbp-140h]
__int128 v21; // [xsp+10h] [xbp-130h]
__int128 v22; // [xsp+20h] [xbp-120h]
__int128 v23; // [xsp+30h] [xbp-110h]
char v24; // [xsp+40h] [xbp-100h]
const __CFString *v25; // [xsp+C0h] [xbp-80h]
const __CFString *v26; // [xsp+C8h] [xbp-78h]
const __CFString *v27; // [xsp+D0h] [xbp-70h]
const __CFString *v28; // [xsp+D8h] [xbp-68h]
const __CFString *v29; // [xsp+E0h] [xbp-60h]
__int64 v30; // [xsp+E8h] [xbp-58h]
v2 = self;
v25 = CFSTR("/Applications/Cydia.app");
v26 = CFSTR("/Library/MobileSubstrate/MobileSubstrate.dylib");
v27 = CFSTR("/bin/bash");
v28 = CFSTR("/usr/sbin/sshd");
v29 = CFSTR("/etc/apt");
v3 = objc_msgSend(&OBJC_CLASS___NSArray, "arrayWithObjects:count:", &v25, 5LL);
v4 = objc_retainAutoreleasedReturnValue(v3);
v20 = 0u;
v21 = 0u;
v22 = 0u;
v23 = 0u;
v5 = (void *)objc_retain(v4);
v6 = v5;
v7 = objc_msgSend(v5, "countByEnumeratingWithState:objects:count:", &v20, &v24, 16LL, 0LL);
if ( v7 )
{
v8 = v7;
v9 = *(_QWORD *)v21;
while ( 2 )
{
v10 = 0LL;
do
{
if ( *(_QWORD *)v21 != v9 )
objc_enumerationMutation(v6);
if ( (unsigned __int64)objc_msgSend(
v2,
"permissionForFile:",
*(_QWORD *)(*((_QWORD *)&v20 + 1) + 8 * v10),
(_QWORD)v20) & 1 )
{
objc_release(v6);
goto LABEL_16;
}
++v10;
}
while ( v10 < (unsigned __int64)v8 );
v8 = objc_msgSend(v6, "countByEnumeratingWithState:objects:count:", &v20, &v24, 16LL, (_QWORD)v20);
if ( v8 )
continue;
break;
}
}
objc_release(v6);
if ( !((unsigned __int64)objc_msgSend(v2, "permissionForFile:", CFSTR("/User/Applications/"), (_QWORD)v20) & 1) )
{
v11 = _dyld_image_count();
if ( !v11 )
{
LABEL_14:
v18 = getenv("DYLD_INSERT_LIBRARIES") != 0LL;
goto LABEL_17;
}
v12 = v11;
v13 = 0;
while ( 1 )
{
v14 = (void *)objc_alloc(&OBJC_CLASS___NSString);
v15 = _dyld_get_image_name(v13);
v16 = objc_msgSend(v14, "initWithUTF8String:", v15, (_QWORD)v20);
v17 = (unsigned __int64)objc_msgSend(v16, "containsString:", CFSTR("MobileSubstrate.dylib"), (_QWORD)v20);
objc_release(v16);
if ( v17 & 1 )
break;
if ( v12 == ++v13 )
goto LABEL_14;
}
}
LABEL_16:
v18 = 1;
LABEL_17:
return v18;
}
结果
1、检测以下路径是否存在：
- /Applications/Cydia.app
- /Library/MobileSubstrate/MobileSubstrate.dylib
- /bin/bash
- /usr/sbin/sshd
- /etc/apt
2、如果路径/User/Applications/不存在，检测getenv(“DYLD_INSERT_LIBRARIES”)是否存在
3、如果路径/User/Applications/不存在，检测当前现在在运行的动态库是否包含MobileSubstrate.dylib
End
阅读此文档的过程中遇到任何问题，请关注公众号【移动端Android和iOS开发技术分享】或加QQ群【812546729】
