[某点资讯Signature逆向]



为了不让别人说这是小号，特意发一贴，大佬勿喷

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:

signature 为加密值；

先上trace下堆栈及加密

我们把结果base64下，看结果是否一致，来判断base64是否魔改

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$VARIANT$mp 0x2328b4b20 CoreFoundation!CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE

我们再hook下：encryptData:withKeyRef:isSign:

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));
    }
});

bool  a5为 0，也就是false,  直接走

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：

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));
    }
});

我去，这不就直接出来了吗

需要加密的值 ："pro6.4.0.00njbh2wlr_1685327378963_38033100" 入参拼接 appid、cv、platform、reqid、version