某点资讯Signature纯算逆向

news2024/12/24 9:03:54

本篇主要是介绍一些工作的运用熟练性，以及跟踪堆栈去看是否做一些其他操作等：

抓包:
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signature 为加密值；

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先上trace下堆栈及加密

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我们把结果base64下，看结果是否一致，来判断base64是否魔改

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验证base64为标准；

根据刚刚的堆栈，跟一下

0x101115468 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!+[RSA encryptData:withKeyRef:isSign:]
0x101115ae0 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!+[RSA encryptData:publicKey:]
0x101115a28 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!+[RSA encryptString:publicKey:]
0x10108a8ac /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[YDRequest getSignatureWithReqId:]
0x10108a6b0 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[YDRequest updateParametersForGet:reqid:]
0x10108aaf4 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[YDRequest initWithURLString:parameters:method:]
0x10108e300 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[HpEngineRequest initWithURLString:parameters:method:]
0x101047544 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[HpEngine refreshNewsListOfKeyword:sinceIndex:]
0x101a17858 /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[HpNewsListDataProvider userRefreshLatestData:]
0x1017be2ac /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[YDNewsListView userRefreshData:]
0x101a235bc /var/containers/Bundle/Application/9580891A-98B0-4F3F-9938-D794221B5B4D/yidian.app/yidian!-[YDNLViewModel didFinishLoadingLocalData:]
0x101a166f0 yidian!0x16ae6f0 (0x1016ae6f0)
0x232360a38 libdispatch.dylib!_dispatch_call_block_and_release
0x2323617d4 libdispatch.dylib!_dispatch_client_callout
0x23230f008 libdispatch.dylib!_dispatch_main_queue_callback_4CF $V A R I A NT$ mp
0x2328b4b20 CoreFoundation!CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE

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我们再hook下：encryptData:withKeyRef:isSign:
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frida -UF -l hook.js 直接附加在该app上

var initWithMethod = ObjC.classes.RSA['+ encryptData:withKeyRef:isSign:'];
Interceptor.attach(initWithMethod.implementation, {
    onEnter: function (args) {
        // console.log('initWithMethod called from:\n' +
        //     Thread.backtrace(this.context, Backtracer.ACCURATE)
        //         .map(DebugSymbol.fromAddress).join('\n') + '\n');
        console.log("args[2]: ",  ObjC.Object(args[2]));
        console.log("args[3]: ", hexdump(args[3]));
        console.log("args[4]: ", args[4]);
    }, onLeave: function (retval) {
        console.log('Base64Encode() this.args1 onLeave：',  hexdump(retval));
    }
});

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bool a5为 0，也就是false, 直接走

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这个时候就明白了吧，这个地方就是上面的最开始trace下堆栈及加密的地方了。

根据堆栈再往上看下吧：

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看到这里也是做了rsa然后base64, 没有其他操作

我们hook下吧：

var initWithMethod = ObjC.classes.RSA['+ encryptString:publicKey:'];
Interceptor.attach(initWithMethod.implementation, {
    onEnter: function (args) {
        // console.log('initWithMethod called from:\n' +
        //     Thread.backtrace(this.context, Backtracer.ACCURATE)
        //         .map(DebugSymbol.fromAddress).join('\n') + '\n');
        console.log("args[2]: ", ObjC.Object(args[2]));
        console.log("args[3]: ", ObjC.Object(args[3]));
        console.log("args[4]: ",hexdump(args[4]));
    }, onLeave: function (retval) {
       console.log('Base64Encode() this.args1 onLeave：',  ObjC.Object(retval));
    }
});