# Adding an Asset (C/C++)

## Available APIs

You can use [OH_Asset_Add](../../reference/apis-asset-store-kit/_asset_api.md#oh_asset_add) to add an asset.

The following table describes the attributes for adding an asset.

>**NOTE**
>
>In the following table, the attributes starting with **ASSET_TAG_DATA_LABEL** are custom asset attributes reserved. These attributes are not encrypted. Therefore, do not put personal data in these attributes.

| Attribute Name (Asset_Tag)           | Attribute Content (Asset_Value)                                      | Mandatory| Description                                                        |
| ------------------------------- | ------------------------------------------------------------ | -------- | ------------------------------------------------------------ |
| ASSET_TAG_SECRET                | Type: uint8[]<br>Length: 1-1024 bytes                             | Yes    | Asset in plaintext.                                                |
| ASSET_TAG_ALIAS                 | Type: uint8[]<br>Length: 1-256 bytes                              | Yes    | Asset alias, which uniquely identifies an asset.                        |
| ASSET_TAG_ACCESSIBILITY         | Type: uint32_t<br>Value range: see [Asset_Accessibility](../../reference/apis-asset-store-kit/_asset_type.md#asset_accessibility)| No    | Access control based on the lock screen status.                                                |
| ASSET_TAG_REQUIRE_PASSWORD_SET  | Type: bool                                                  | No    | Whether the asset is accessible only when a lock screen password is set.                |
| ASSET_TAG_AUTH_TYPE             | Type: uint32_t<br>Value range: see [Asset_AuthType](../../reference/apis-asset-store-kit/_asset_type.md#asset_authtype)| No    | Type of user authentication required for accessing the asset.                              |
| ASSET_TAG_SYNC_TYPE             | Type: uint32_t<br>Value range: see [Asset_SyncType](../../reference/apis-asset-store-kit/_asset_type.md#asset_synctype)| No    | Type of sync supported by the asset.                                      |
| ASSET_TAG_IS_PERSISTENT         | Type: bool                                                  | No    | Whether to retain the asset when the application is uninstalled.<br>**NOTE**: If this parameter is set, the application must [apply for](../AccessToken/declare-permissions.md) the ohos.permission.STORE_PERSISTENT_DATA permission.|
| ASSET_TAG_DATA_LABEL_CRITICAL_1 | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service with integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_CRITICAL_2 | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service with integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_CRITICAL_3 | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service with integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_CRITICAL_4 | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service with integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_NORMAL_1   | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service without integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_NORMAL_2   | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service without integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_NORMAL_3   | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service without integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_NORMAL_4   | Type: uint8[]<br>Length: 1-2048 bytes                          | No    | Asset attribute information customized by the service without integrity protection.<br>**NOTE**: The data length is 1 to 512 bytes before API version 12.|
| ASSET_TAG_DATA_LABEL_NORMAL_LOCAL_1<sup>12+</sup> | Type: uint8[]<br>Length: 1-2048 bytes| No| Local attribute information about the asset. The value is assigned by the service without integrity protection and will not be synced.|
| ASSET_TAG_DATA_LABEL_NORMAL_LOCAL_2<sup>12+</sup> | Type: uint8[]<br>Length: 1-2048 bytes| No| Local attribute information about the asset. The value is assigned by the service without integrity protection and will not be synced.|
| ASSET_TAG_DATA_LABEL_NORMAL_LOCAL_3<sup>12+</sup> | Type: uint8[]<br>Length: 1-2048 bytes| No| Local attribute information about the asset. The value is assigned by the service without integrity protection and will not be synced.|
| ASSET_TAG_DATA_LABEL_NORMAL_LOCAL_4<sup>12+</sup> | Type: uint8[]<br>Length: 1-2048 bytes| No| Local attribute information about the asset. The value is assigned by the service without integrity protection and will not be synced.|
| ASSET_TAG_CONFLICT_RESOLUTION   | Type: uint32_t<br>Value range: see [Asset_ConflictResolution](../../reference/apis-asset-store-kit/_asset_type.md#asset_conflictresolution)| No    | Policy for resolving the conflict (for example, duplicate alias).                            |
| ASSET_TAG_REQUIRE_ATTR_ENCRYPTED<sup>14+</sup> | Type: bool| No| Whether to encrypt the customized asset attribute information. By default, the customized asset attribute information is not encrypted.|

## Constraints

* Alias-based access

  Assets are stored in the ASSET database in ciphertext and uniquely identified by the service identity and alias. The alias of each asset must be unique.

* Custom service data storage

  ASSET provides 12 custom asset attributes starting with **ASSET_TAG_DATA_LABEL** for services. If the 12 custom attributes are used, you can combine multiple data segments in a certain format (for example, JSON) into an ASSET attribute.

  ASSET protects the integrity of the attributes starting with **ASSET_TAG_DATA_LABEL_CRITICAL**. These attributes cannot be changed once written.

## Example

Add an asset that is accessible when the user unlocks the device for the first time. The asset includes password **demo_pwd**, alias **demo_alias**, and additional information **demo_label**.

1. Add the dynamic library in the CMake script.
   ```txt
   target_link_libraries(entry PUBLIC libasset_ndk.z.so)
   ```

2. Add an asset.
   ```c
   #include <string.h>

   #include "asset/asset_api.h"

   void AddAsset() {
      static const char *SECRET = "demo_pwd";
      static const char *ALIAS = "demo_alias";
      static const char *LABEL = "demo_label";

      Asset_Blob secret = { (uint32_t)(strlen(SECRET)), (uint8_t *)SECRET };
      Asset_Blob alias = { (uint32_t)(strlen(ALIAS)), (uint8_t *)ALIAS };
      Asset_Blob label = { (uint32_t)(strlen(LABEL)), (uint8_t *)LABEL };
      Asset_Attr attr[] = {
         { .tag = ASSET_TAG_ACCESSIBILITY, .value.u32 = ASSET_ACCESSIBILITY_DEVICE_FIRST_UNLOCKED },
         { .tag = ASSET_TAG_SECRET, .value.blob = secret },
         { .tag = ASSET_TAG_ALIAS, .value.blob = alias },
         { .tag = ASSET_TAG_DATA_LABEL_NORMAL_1, .value.blob = label },
      };

      int32_t ret = OH_Asset_Add(attr, sizeof(attr) / sizeof(attr[0]));
      if (ret == ASSET_SUCCESS) {
         // Asset added successfully.
      } else {
         // Failed to add Asset.
      }
   }
   ```