【爱加密】Android APP利用无效字节码防止工具逆向破解(一)

【爱加密】Android APP利用无效字节码防止工具逆向破解(一) 【爱加密】Android APP利用无效字节码防止工具逆向破解(一) 由于大部分逆向工具都是线性读取字节码并解析，当遇到无效字节码时，就会引起反编译工具字节码解析失败。我们可以插入无效字节码到DEX文件，但要保证该无效字节码永远不会被执行(否则您的程序就会崩溃了～)。 用到的工具: IDA、C32Asm、DexFixer、Ijiami signer(爱加密签名工具)、 (由于百度文档限制，使用的工具无法添加连接。请自行到网上下载，带来的不便请谅解～) 首先我们新建一个测试类。为了绕过Dalvik运行时代码验证，BadCode.java要保证不被调用。(否则运行app，会出现java.lang.verifyerror常) 然后生成apk，用ida打开classes.dex。并找到BadCode类的aaa方法。选中的三行代码对应”System.out.println("aaaa");” located in the Tomb, Dong Shen Jia bang, defer the next day focused on the assassination. Linping, Zhejiang, 1 of which liquor wine masters (Wuzhen said information is Carpenter), who got A few bayonets, due to missed fatal, when night came 切换到HexView-a视图，记录下指令码 “62 00 02 04 1A 01 8E 07 6E 20 19 10 10 00” 和对应偏移“0003A2A4” 使用C32asm，以十六进制的方式打开dex文件。按快捷键“Ctrl + G”，定位到“0003A2A4” 把“62 00 02 04 1A 01 8E 07 6E 20 19 10 10 00”改为“12 01 38 01 03 00 FF FF 00 00 00 00 00 00” Opcodes解释: 12 01 // const/4 v1, 0 //v1=0 38 01 03 00 // if-eqz v1, loc_3A2AC //if(v1==0) 跳转到 loc_3A2AC: FF FF // FFFF (Bad opcodes) //本行代码被跳过永远不会执行 // loc_3A2AC: 保存dex。把修改后的dex文件拖入DexFixer进行修复。 用修复后的dex覆盖原apk中的dex文件。 located in the Tomb, Dong Shen Jia bang, defer the next day focused on the assassination. Linping, Zhejiang, 1 of which liquor wine masters (Wuzhen said information is Carpenter), who got A few bayonets, due to missed fatal, when night came 删除META-INF签名文件 使用签名工具，对apk重新签名。 Apk安装到手机，运行成功 下面试试反逆向工具的效果 Apktool:(很遗憾，新版本已经修复了这个错误) located in the Tomb, Dong Shen Jia bang, defer the next day focused on the assassination. Linping, Zhejiang, 1 of which liquor wine masters (Wuzhen said information is Carpenter), who got A few bayonets, due to missed fatal, when night came Dex2jar:(反编译失败) located in the Tomb, Dong Shen Jia bang, defer the next day focused on the assassination. Linping, Zhejiang, 1 of which liquor wine masters (Wuzhen said information is Carpenter), who got A few bayonets, due to missed fatal, when night came