使用jni技术进行android应用签名信息核查及敏感信息保护

jstring loadSignature(JNIEnv* env, jobject obj)
{
	// 获得Context类
    jclass cls = (*env)->GetObjectClass(env, obj);
    // 得到getPackageManager方法的ID
    jmethodID mid = (*env)->GetMethodID(env, cls, "getPackageManager", "()Landroid/content/pm/PackageManager;");

    // 获得应用包的管理器
    jobject pm = (*env)->CallObjectMethod(env, obj, mid);

    // 得到getPackageName方法的ID
    mid = (*env)->GetMethodID(env, cls, "getPackageName", "()Ljava/lang/String;");
    // 获得当前应用包名
    jstring packageName = (jstring)(*env)->CallObjectMethod(env, obj, mid);

    // 获得PackageManager类
    cls = (*env)->GetObjectClass(env, pm);
    // 得到getPackageInfo方法的ID
    mid  = (*env)->GetMethodID(env, cls, "getPackageInfo", "(Ljava/lang/String;I)Landroid/content/pm/PackageInfo;");
    // 获得应用包的信息
    jobject packageInfo = (*env)->CallObjectMethod(env, pm, mid, packageName, 0x40); //GET_SIGNATURES = 64;
    // 获得PackageInfo 类
    cls = (*env)->GetObjectClass(env, packageInfo);
    // 获得签名数组属性的ID
    jfieldID fid = (*env)->GetFieldID(env, cls, "signatures", "[Landroid/content/pm/Signature;");
    // 得到签名数组
    jobjectArray signatures = (jobjectArray)(*env)->GetObjectField(env, packageInfo, fid);
    // 得到签名
    jobject sign = (*env)->GetObjectArrayElement(env, signatures, 0);

    // 获得Signature类
    cls = (*env)->GetObjectClass(env, sign);
    // 得到toCharsString方法的ID
    mid = (*env)->GetMethodID(env, cls, "toCharsString", "()Ljava/lang/String;");

    // 返回当前应用签名信息
    return (jstring)(*env)->CallObjectMethod(env, sign, mid);
}