iOS逆向之iOSOpenDev

上篇谈到使用TheOS进行越狱开发，但是流程相对而言较复杂，本篇我们谈一下iOSOpenDev进行越狱开发。通过使用iOSOpenDev，我们可以使用Xcode进行开发、编译、生成并运行到设备上。

1.安装iOSOpenDev

打开网址：http://iosopendev.com/download/，选择“iOSOpenDev 1.6-2 Installer”，下载完成之后，直接安装pkg文件。在安装过程中，有可能出现失败，按照这篇文章介绍的方法，进行处理。
安装成功后，打开XCode，新建工程，我们可以看到iOSOpenDev已经集成在XCode中了，并附带了很多模板：

2.使用iOSOpenDev

第一步：新建工程，这里选择“Logos Tweak”，新建完成之后，工程结构如下图所示：

可以看到有一个.xm文件，我们打开看一下内容：

// Logos by Dustin Howett
// See http://iphonedevwiki.net/index.php/Logos

#error iOSOpenDev post-project creation from template requirements (remove these lines after completed) -- \
    Link to libsubstrate.dylib: \
    (1) go to TARGETS > Build Phases > Link Binary With Libraries and add /opt/iOSOpenDev/lib/libsubstrate.dylib \
    (2) remove these lines from *.xm files (not *.mm files as they're automatically generated from *.xm files)

%hook ClassName

+ (id)sharedInstance
{
    %log;

    return %orig;
}

- (void)messageWithNoReturnAndOneArgument:(id)originalArgument
{
    %log;

    %orig(originalArgument);
    
    // or, for exmaple, you could use a custom value instead of the original argument: %orig(customValue);
}

- (id)messageWithReturnAndNoArguments
{
    %log;

    id originalReturnOfMessage = %orig;
    
    // for example, you could modify the original return value before returning it: [SomeOtherClass doSomethingToThisObject:originalReturnOfMessage];

    return originalReturnOfMessage;
}

%end

.xm文件提示需要链接 libsubstrate.dylib，另外看一下很多%开头的语句。%是Legos中的指示符，和TheOS中一样。

这里先把.xm文件的内容清空，然后ibsubstrate.dylib链接进来，另外也把UIKit（因为我们需要一个提示框显示信息）链接进来：

和TheOS一样，这里我们也只是显示一个Alert框，代码也一样：

#import <UIKit/UIKit.h>

%hook SpringBoard

-(void)applicationDidFinishLaunching:(id)application {
    %orig;

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Hello, Gof!" message:@"LeeGof is very handsome" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
}

%end

再看一下.mm文件，已经自动根据.xm文件生成了如下代码：

#line 1 "/Users/GofLee/Desktop/逆向工程/code/TweakDemo/TweakDemo/TweakDemo.xm"
#import <UIKit/UIKit.h>


#include <substrate.h>
#if defined(__clang__)
#if __has_feature(objc_arc)
#define _LOGOS_SELF_TYPE_NORMAL __unsafe_unretained
#define _LOGOS_SELF_TYPE_INIT __attribute__((ns_consumed))
#define _LOGOS_SELF_CONST const
#define _LOGOS_RETURN_RETAINED __attribute__((ns_returns_retained))
#else
#define _LOGOS_SELF_TYPE_NORMAL
#define _LOGOS_SELF_TYPE_INIT
#define _LOGOS_SELF_CONST
#define _LOGOS_RETURN_RETAINED
#endif
#else
#define _LOGOS_SELF_TYPE_NORMAL
#define _LOGOS_SELF_TYPE_INIT
#define _LOGOS_SELF_CONST
#define _LOGOS_RETURN_RETAINED
#endif

@class SpringBoard; 
static void (*_logos_orig$_ungrouped$SpringBoard$applicationDidFinishLaunching$)(_LOGOS_SELF_TYPE_NORMAL SpringBoard* _LOGOS_SELF_CONST, SEL, id); static void _logos_method$_ungrouped$SpringBoard$applicationDidFinishLaunching$(_LOGOS_SELF_TYPE_NORMAL SpringBoard* _LOGOS_SELF_CONST, SEL, id); 

#line 3 "/Users/GofLee/Desktop/逆向工程/code/TweakDemo/TweakDemo/TweakDemo.xm"


static void _logos_method$_ungrouped$SpringBoard$applicationDidFinishLaunching$(_LOGOS_SELF_TYPE_NORMAL SpringBoard* _LOGOS_SELF_CONST self, SEL _cmd, id application) {
    _logos_orig$_ungrouped$SpringBoard$applicationDidFinishLaunching$(self, _cmd, application);

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Hello, Gof!" message:@"LeeGof is very handsome" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [alert show];
}


static __attribute__((constructor)) void _logosLocalInit() {
{Class _logos_class$_ungrouped$SpringBoard = objc_getClass("SpringBoard"); if (_logos_class$_ungrouped$SpringBoard) {MSHookMessageEx(_logos_class$_ungrouped$SpringBoard, @selector(applicationDidFinishLaunching:), (IMP)&_logos_method$_ungrouped$SpringBoard$applicationDidFinishLaunching$, (IMP*)&_logos_orig$_ungrouped$SpringBoard$applicationDidFinishLaunching$);} else {HBLogError(@"logos: nil class %s", "SpringBoard");}} }
#line 13 "/Users/GofLee/Desktop/逆向工程/code/TweakDemo/TweakDemo/TweakDemo.xm"