【IOS逆向】frida-trace小计

当越狱完成之后，可以尝试品尝下frida

frida-trace 用于跟踪函数或者 Objective-C 方法的调用，frida-trace -h 能够查看它的帮助，最重要的有下面几个参数：

-i 跟踪某个函数，-x 排除某个函数。
-m 跟踪某个 Objective-C 方法，-M 排除某个 Objective-C 方法。
-a 跟踪某一个地址，需要指名模块的名称。

frida-trace

 ~  frida-trace -U -m "-[HomeController aboutButtonClicked]" 1375
Instrumenting...
-[HomeController aboutButtonClicked]: Loaded handler at "/Users/xxxx/__handlers__/HomeController/aboutButtonClicked.js"
Started tracing 1 function. Press Ctrl+C to stop.
           /* TID 0x303 */
  2896 ms  -[HomeController aboutButtonClicked]

其中1375是cydia的pid

然后输出的文件中可以添加我们自定义的代码

打印堆栈

{

  onEnter(log, args, state) {
    log(`-[HomeController aboutButtonClicked]`);
    log('\tBacktrace:\n\t' + Thread.backtrace(this.context,Backtracer.ACCURATE).map(DebugSymbol.fromAddress).join('\n\t'));
  },

  onLeave(log, retval, state) {
  }
}

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通配符

frida-trace -U -m "-[Home* *]" 1375

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trace CCCrypt

很多应用在登录时都会加密数据，我们的目标是获取某个应用的 AES 加密的原文和密钥

frida-trace -U -i CCCrypt xxxx

在这里插入图片描述
会发现他自动识别了CCrypt这个库
并自动生成了js我们看看

/*
 * Auto-generated by Frida. Please modify to match the signature of CCCrypt.
 * This stub is currently auto-generated from manpages when available.
 *
 * For full API reference, see: https://frida.re/docs/javascript-api/
 */

{
  /**
   * Called synchronously when about to call CCCrypt.
   *
   * @this {object} - Object allowing you to store state for use in onLeave.
   * @param {function} log - Call this function with a string to be presented to the user.
   * @param {array} args - Function arguments represented as an array of NativePointer objects.
   * For example use args[0].readUtf8String() if the first argument is a pointer to a C string encoded as UTF-8.
   * It is also possible to modify arguments by assigning a NativePointer object to an element of this array.
   * @param {object} state - Object allowing you to keep state across function calls.
   * Only one JavaScript function will execute at a time, so do not worry about race-conditions.
   * However, do not use this to store function arguments across onEnter/onLeave, but instead
   * use "this" which is an object for keeping state local to an invocation.
   */
  onEnter(log, args, state) {
    log(`CCCrypt(op=${args[0]}, alg=${args[1]}, options=${args[2]}, key=${args[3]}, keyLength=${args[4]}, iv=${args[5]}, dataIn=${args[6]}, dataInLength=${args[7]}, dataOut=${args[8]}, dataOutAvailable=${args[9]}, dataOutMoved=${args[10]})`);
  },

  /**
   * Called synchronously when about to return from CCCrypt.
   *
   * See onEnter for details.
   *
   * @this {object} - Object allowing you to access state stored in onEnter.
   * @param {function} log - Call this function with a string to be presented to the user.
   * @param {NativePointer} retval - Return value represented as a NativePointer object.
   * @param {object} state - Object allowing you to keep state across function calls.
   */
  onLeave(log, retval, state) {
  }
}

魔改一下

{
  onEnter(log, args, state) {
    log(`CCCrypt(op=${args[0]}, alg=${args[1]}, options=${args[2]}, key=${args[3]}, keyLength=${args[4]}, iv=${args[5]}, dataIn=${args[6]}, dataInLength=${args[7]}, dataOut=${args[8]}, dataOutAvailable=${args[9]}, dataOutMoved=${args[10]})`);
    //保存参数
    this.operation   = args[0]
    this.CCAlgorithm = args[1]
    this.CCOptions   = args[2]
    this.keyBytes    = args[3]
    this.keyLength   = args[4]
    this.ivBuffer    = args[5]
    this.inBuffer    = args[6]
    this.inLength    = args[7]
    this.outBuffer   = args[8]
    this.outLength   = args[9]
    this.outCountPtr = args[10]
 
    //this.operation == 0 代表是加密
    if (this.operation == 0) {
        //打印加密前的原文
        console.log("In buffer:")
        console.log(hexdump(ptr(this.inBuffer), {
            length: this.inLength.toInt32(),
            header: true,
            ansi: true
        }))
        //打印密钥
        console.log("Key: ")
        console.log(hexdump(ptr(this.keyBytes), {
            length: this.keyLength.toInt32(),
            header: true,
            ansi: true
        }))
        //打印 IV
        console.log("IV: ")
        console.log(hexdump(ptr(this.ivBuffer), {
            length: this.keyLength.toInt32(),
            header: true,
            ansi: true
        }))
    }
  },
  onLeave(log, retval, state) {
  }
}