(转) android so 文件存私密数据，且防止 so文件未知应用盗用

android so 文件存私密数据，且防止 so文件未知应用盗用

 

       有时候我们需要在客户端 存放一些 保密的数据，比如 服务端的IP 端口，接口的地址，授权的key 等等，如果我们直接写在java中，别人反编译就能看到，那么我们可以把这些数据 存在  so文件中，这样别人就不可能会看到了，顺便 so里面验证 app的签名 来防止别人盗用so文件,

下面的例子是 在so里面获取我的客户端key

1.jni的java文件   JNI.java

package com.android.jni;

import android.content.Context;

public class JNI {

     static{
         System.loadLibrary("auth");
     }

     /**
      * 获取api 调用授权 key
      * @param signature 应用签名信息，防止http 接口  授权 key 被盗用
      * @return
      */
     public native String getAuthKey(Context context);

}

2. .h头文件  com_android_jni_JNI.h

/* DO NOT EDIT THIS FILE - it is machine generated */
#include <jni.h>
/* Header for class com_android_jni_JNI */

#ifndef _Included_com_android_jni_JNI
#define _Included_com_android_jni_JNI
#ifdef __cplusplus
extern "C" {
#endif
/*
 * Class:     com_android_jni_JNI
 * Method:    getAuthKey
 * Signature: (Landroid/content/pm/Signature;)Ljava/lang/String;
 */
JNIEXPORT jstring JNICALL Java_com_android_jni_JNI_getAuthKey
  (JNIEnv *, jobject, jobject);

#ifdef __cplusplus
}
#endif
#endif

3. so的 c++实现  com_android_jni_JNI.cpp

#include <jni.h>
#include <string.h>
#include <stdio.h>
#include <com_android_jni_JNI.h>
/**
 * http api 授权 key ，由服务端提供
 */
const char* AUTH_KEY = "0CC175B9C0F1B6A831C399E269772661";

/**
 * 发布的app 签名,只有和本签名一致的app 才会返回合法的 授权 key
 */
const char* RELEASE_SIGN ="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";

/**
 * 拿到传入的app  的 签名信息，对比合法的app 签名，防止so文件被未知应用盗用
 */
static jclass contextClass;
static jclass signatureClass;
static jclass packageNameClass;
static jclass packageInfoClass;
JNIEXPORT jstring JNICALL Java_com_android_jni_JNI_getAuthKey(
        JNIEnv * env, jobject obj, jobject contextObject) {

    jmethodID getPackageManagerId = (env)->GetMethodID(contextClass, "getPackageManager","()Landroid/content/pm/PackageManager;");
    jmethodID getPackageNameId = (env)->GetMethodID(contextClass, "getPackageName","()Ljava/lang/String;");
    jmethodID signToStringId = (env)->GetMethodID(signatureClass, "toCharsString","()Ljava/lang/String;");
    jmethodID getPackageInfoId = (env)->GetMethodID(packageNameClass, "getPackageInfo","(Ljava/lang/String;I)Landroid/content/pm/PackageInfo;");
    jobject packageManagerObject =  (env)->CallObjectMethod(contextObject, getPackageManagerId);
    jstring packNameString =  (jstring)(env)->CallObjectMethod(contextObject, getPackageNameId);
    jobject packageInfoObject = (env)->CallObjectMethod(packageManagerObject, getPackageInfoId,packNameString, 64);
    jfieldID signaturefieldID =(env)->GetFieldID(packageInfoClass,"signatures", "[Landroid/content/pm/Signature;");
    jobjectArray signatureArray = (jobjectArray)(env)->GetObjectField(packageInfoObject, signaturefieldID);
    jobject signatureObject =  (env)->GetObjectArrayElement(signatureArray,0);

    const char* signStrng =  (env)->GetStringUTFChars((jstring)(env)->CallObjectMethod(signatureObject, signToStringId),0);
    if(strcmp(signStrng,RELEASE_SIGN)==0)//签名一致  返回合法的 api key，否则返回错误
    {
       return (env)->NewStringUTF(AUTH_KEY);
    }else
    {
       return (env)->NewStringUTF("error");
    }

}


JNIEXPORT jint JNICALL JNI_OnLoad (JavaVM* vm,void* reserved){

     JNIEnv* env = NULL;
     jint result=-1;
     if(vm->GetEnv((void**)&env, JNI_VERSION_1_4) != JNI_OK)
       return result;

     contextClass = (jclass)env->NewGlobalRef((env)->FindClass("android/content/Context"));
     signatureClass = (jclass)env->NewGlobalRef((env)->FindClass("android/content/pm/Signature"));
     packageNameClass = (jclass)env->NewGlobalRef((env)->FindClass("android/content/pm/PackageManager"));
     packageInfoClass = (jclass)env->NewGlobalRef((env)->FindClass("android/content/pm/PackageInfo"));

     return JNI_VERSION_1_4;
 }

关于如何获取正式keystone签名的问题

先打一个正式的包，代码里面获取到签名，然后再log里面打印出来，copy到cpp文件里面编译so即可，下面是android里面获取签名字符串的代码

public static String getSignature(Context context)
    {
        try {
            /** 通过包管理器获得指定包名包含签名的包信息 **/
            PackageInfo packageInfo = context.getPackageManager().getPackageInfo(context.getPackageName(), PackageManager.GET_SIGNATURES);
            /******* 通过返回的包信息获得签名数组 *******/
            Signature[] signatures = packageInfo.signatures;
            /******* 循环遍历签名数组拼接应用签名 *******/
            return signatures[0].toCharsString();
            /************** 得到应用签名 **************/
        } catch (NameNotFoundException e) {
            e.printStackTrace();
        }

        return null;
    }