flutter抓包绕过

lutter的证书校验

起因：

最近工作上让做个app的复测，把apk发我后，开始尝试挂代理抓包，结果发现抓不到

为是证书没弄好，想着前几天不是刚导入了吗（雾）。又重新导入了下还是不行。然后各种lsp模块，objection都不行，r0capture也没数据。
然后jadx看了下，全是flutter字样，才想起来和flutter有关。 

开始百度（：

然后就开始各种找。
 

session_verify_cert_chain函数在第356行的ssl_x509.cc中被定义 

然后根据[原创]一种基于frida和drony的针对flutter抓包的方法-Android安全-看雪-安全社区|安全招聘|kanxue.com 这篇文章特征找，但是这个是32位的，所以在app安装的时候指定32位安装

 

写脚本绕过

32位

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function hook_ssl_verify_result(address) { Interceptor.attach(address, {         onEnter: function(args) {             console.log("Disabling SSL validation")         },         onLeave: function(retval) {             console.log("Retval: " + retval);             retval.replace(0x1);         }     }); } function hookFlutter() {     var m = Process.findModuleByName("libflutter.so");     var pattern = "2D E9 F0 4F 85 B0 06 46 50 20 10 70";     var res = Memory.scan(m.base, m.size, pattern, {         onMatch: function(address, size){             console.log('[+] ssl_verify_result found at: ' + address.toString());         // Add 0x01 because it's a THUMB function         // Otherwise, we would get 'Error: unable to intercept function at 0x9906f8ac; please file a bug'             hook_ssl_verify_result(address.add(0x01));         },         onError: function(reason){             console.log('[!] There was an error scanning memory');         },         onComplete: function() {             console.log("All done")         }     }); }

然后启动就可以抓包了

64位

搜索ssl_client

 

然后就找到了这些

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.text:0000000000596870 FF C3 01 D1                 SUB             SP, SP, #0x70 .text:0000000000596874 FD 7B 01 A9                 STP             X29, X30, [SP,#0x70+var_60] .text:0000000000596878 FC 6F 02 A9                 STP             X28, X27, [SP,#0x70+var_50] .text:000000000059687C FA 67 03 A9                 STP             X26, X25, [SP,#0x70+var_40] .text:0000000000596880 F8 5F 04 A9                 STP             X24, X23, [SP,#0x70+var_30] .text:0000000000596884 F6 57 05 A9                 STP             X22, X21, [SP,#0x70+var_20] .text:0000000000596888 F4 4F 06 A9                 STP             X20, X19, [SP,#0x70+var_10] .text:000000000059688C 08 0A 80 52                 MOV             W8, #0x50 .text:0000000000596890 48 00 00 39                 STRB            W8, [X2]

然后写脚本

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function hook_ssl_verify_result(address) { Interceptor.attach(address, {         onEnter: function(args) {             console.log("Disabling SSL validation")         },         onLeave: function(retval) {             console.log("Retval: " + retval);             retval.replace(0x1);         }     }); } function hookFlutter() {     var m = Process.findModuleByName("libflutter.so");     var pattern = "FF C3 01 D1 FD 7B 01 A9 FC 6F 02 A9FA 67 03 A9 F8 5F 04 A9 F6 57 05 A9 F4 4F 06 A9 08 0A 80 52 48 00 00 39";     var res = Memory.scan(m.base, m.size, pattern, {         onMatch: function(address, size){             console.log('[+] ssl_verify_result found at: ' + address.toString());         // Add 0x01 because it's a THUMB function         // Otherwise, we would get 'Error: unable to intercept function at 0x9906f8ac; please file a bug'             hook_ssl_verify_result(address.add(0x01));         },         onError: function(reason){             console.log('[!] There was an error scanning memory');         },         onComplete: function() {             console.log("All done")         }     }); }

然后发现报错了