OP-TEE CA中多次创建一个文件，出错：ReturnCode=0Xffff ReturnOrigin=0x04

在OP-TEE黄皮书中有关于文件保存的章节：
章节secStor_test和密钥下发章节save_key；

Invokecommand failed,ReturnCode=0Xffff ReturnOrigin=0x04

屏蔽掉删除函数，去重复的创建、写、读、创建 然后就会出上述 错误提示；

test_fun()
{
	g_SecStorCa_CreateFile();
	g_SecStorCa_WiteFile();
	g_SecStorCa_ReadFile();
	//g_SecStorCa_DeleteFile();
}

自从我发现了这个bug之后，就各种手贱去点他。并尝试从错误代码找该bug的结局方案。

一位业内大神这样说：《你把详细的错误信息好好看看追追，说不定就找到问题了。》

另外一位大神（帅峰云），《你在重新创建的时候是否又先close一下， 在代码中加一些Log看看报错在哪里，然后追一下代码》

后来在我实际使用过程中发现，严谨点根本不会出这种问题，比如你可以这样处理：
写函数：

TEEC_Result ca_write(char * name, char * buf, int length)
{ 
 TEEC_Result res;
 printf("-execute write tast.\n");
 res = read_secure_object(&ctx, name,
       buf, sizeof(buf));
 
 if (res != TEEC_SUCCESS && res != TEEC_ERROR_ITEM_NOT_FOUND)
 {
   errx(1, "Unexpected status when reading an object : 0x%x", res);
 }
   
 if (res == TEEC_ERROR_ITEM_NOT_FOUND) {
   //char data[] = "This is data stored in the secure storage.\n";
 
   printf("- Object not found in TA secure storage, create it.\n");
 
   res = write_secure_object(&ctx, name,
        buf, sizeof(buf));
   if (res != TEEC_SUCCESS)
   {
    errx(1, "Failed to create/load an object");
   }else {
    printf("-first write success.\n");
   }
 
 } else if (res == TEEC_SUCCESS) {
   printf("- Object found in TA secure storage, delete it.\n");
 
   res = delete_secure_object(&ctx, name);
   if (res != TEEC_SUCCESS)
   {
    errx(1, "Failed to delete an object");
   }
   res = write_secure_object(&ctx, name,
        buf, sizeof(buf));
   if (res != TEEC_SUCCESS)
   {
    errx(1, "Failed to create/load an object");
   }else {
    printf("-first delete is ,ren write success.\n");
   }  
 } 
 return res;
}

读函数：

TEEC_Result ca_read(char * name, char * buf, int length)
{ 
 TEEC_Result res;
 printf("-execute write tast.\n");
 res = read_secure_object(&ctx, name,
       buf, sizeof(buf));
 
 if (res != TEEC_SUCCESS && res != TEEC_ERROR_ITEM_NOT_FOUND)
 {
   errx(1, "Unexpected status when reading an object : 0x%x", res);
 }
   
 if (res == TEEC_ERROR_ITEM_NOT_FOUND) {
   //char data[] = "This is data stored in the secure storage.\n";
 
   printf("- First read this file,Object not found in TA secure storage, create it.\n");
 
   res = write_secure_object(&ctx, name,
        buf, sizeof(buf));
   if (res != TEEC_SUCCESS)
   {
    errx(1, "Failed to create/load an object");
   }else {
    printf("-first write success.\n");
   }
 
 } else if (res == TEEC_SUCCESS) 
 {
   printf("- Object found in TA secure storage, read it.\n");
 } 
 return res;
}