安卓逆向 -- 自吐算法（MAC）

import javax.crypto.Mac
import javax.crypto.spec.SecretKeySpec
String bs= "逆向有你a";
SecretKeySpec key = new SecretKeySpec("12345".getBytes(StandardCharsets.UTF_8), "HmacSHA256");//申请一个密钥，长度内容随便写
Mac mac = Mac.getInstance("HmacSHA256");//告诉系统我用的加密码方式是HmacSHA256
mac.init(key);
byte[] macres = mac.doFinal(bs.getBytes(StandardCharsets.UTF_8));//开始加密
System.out.println("HmacSHA1加密（字节）："+Arrays.toString(macres));
System.out.println("HmacSHA1加密（字符串）："+bytes2HexString(macres));
SecretKeySpec key1 = new SecretKeySpec("12345".getBytes(StandardCharsets.UTF_8), "HmacSHA256");//申请一个密钥，长度内容随便写
Mac mac1 = Mac.getInstance("HmacSHA256");//告诉系统我用的加密码方式是HmacSHA256
mac1.init(key1);
mac1.update("逆向".getBytes(StandardCharsets.UTF_8));
mac1.update("有你".getBytes(StandardCharsets.UTF_8));
byte[] macres1 = mac1.doFinal("a".getBytes(StandardCharsets.UTF_8));
System.out.println(bytes2HexString(macres1));

XposedBridge.hookAllMethods(XposedHelpers.findClass("javax.crypto.Mac", loadPackageParam.classLoader)
        , "doFinal",
        new XC_MethodHook() {
            @Override
            protected void afterHookedMethod(MethodHookParam param) throws Throwable {
                super.afterHookedMethod(param);
                Log.e("逆向有你", "Stack：", new Throwable("stack dump"));
                if(param.args.length==2) return;
                Mac mc = (Mac) param.thisObject;//实例化
                String algorithm = mc.getAlgorithm();//获取加密算法的名称
                if (param.args.length == 2) {
                    byte[] params = (byte[]) param.args[0];
                    String data = new String(params);
                    String datahex = b2s(params);
                    String datab64 = Base64.encodeToString(params, 0);
                    Log.d("逆向有你",algorithm+"data:"+data);
                    Log.d("逆向有你",algorithm+"datahex:"+datahex);
                    Log.d("逆向有你",algorithm+"datab64:"+datab64);
                }
                byte[] res=(byte[])param.getResult();
                String reshex = b2s(res);
                String resb64 = Base64.encodeToString(res, 0);
                Log.d("逆向有你",algorithm+"resulthex:"+reshex);
                Log.d("逆向有你",algorithm+"resultb64:"+resb64);
                Log.d("逆向有你","========================================================================");
            }
        });
XposedBridge.hookAllConstructors(XposedHelpers.findClass("javax.crypto.spec.SecretKeySpec", loadPackageParam.classLoader)
        , new XC_MethodHook() {
            @Override
            protected void afterHookedMethod(MethodHookParam param) throws Throwable {
                super.afterHookedMethod(param);
                Log.e("逆向有你", "Stack：", new Throwable("stack dump"));
                byte[] secretKey = (byte[]) param.args[0];
                int offset=0;
                int size=0;
                String algorithm=null;
                if (param.args.length != 2) {
                    offset = ((Integer) param.args[1]).intValue();
                    size = ((Integer) param.args[2]).intValue();
                    algorithm = (String) param.args[3];
                }else
                {
                    size=secretKey.length;
                    algorithm= (String) param.args[1];
                }
                byte[] keyres=new byte[size];
                System.arraycopy(secretKey,offset,keyres,0,size);
                String keyreshex = b2s(keyres);
                String keyresb64 = Base64.encodeToString(keyres, 0);
                Log.d("逆向有你",algorithm+"secretkey:"+new String(keyres));
                Log.d("逆向有你",algorithm+"secretkeyhex:"+keyreshex);
                Log.d("逆向有你",algorithm+"secretkeyb64:"+keyresb64);
                Log.d("逆向有你","========================================================================");
            }
        });