harmony 鸿蒙Adding an Asset (C/C++)

2025-06-12
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Adding an Asset (C/C++)

Available APIs

You can use 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[] Length: 1-1024 bytes	Yes	Asset in plaintext.
ASSET_TAG_ALIAS	Type: uint8[] Length: 1-256 bytes	Yes	Asset alias, which uniquely identifies an asset.
ASSET_TAG_ACCESSIBILITY	Type: uint32_t Value range: see 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 Value range: see Asset_AuthType	No	Type of user authentication required for accessing the asset.
ASSET_TAG_SYNC_TYPE	Type: uint32_t Value range: see 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. NOTE: If this parameter is set, the application must apply for the ohos.permission.STORE_PERSISTENT_DATA permission.
ASSET_TAG_DATA_LABEL_CRITICAL_1	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service with integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_CRITICAL_2	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service with integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_CRITICAL_3	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service with integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_CRITICAL_4	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service with integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_NORMAL_1	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service without integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_NORMAL_2	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service without integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_NORMAL_3	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service without integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_NORMAL_4	Type: uint8[] Length: 1-2048 bytes	No	Asset attribute information customized by the service without integrity protection. NOTE: The data length is 1 to 512 bytes before API version 12.
ASSET_TAG_DATA_LABEL_NORMAL_LOCAL_1¹²⁺	Type: uint8[] 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_2¹²⁺	Type: uint8[] 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_3¹²⁺	Type: uint8[] 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_4¹²⁺	Type: uint8[] 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 Value range: see Asset_ConflictResolution	No	Policy for resolving the conflict (for example, duplicate alias).
ASSET_TAG_REQUIRE_ATTR_ENCRYPTED¹⁴⁺	Type: bool	No	Whether to encrypt the customized asset attribute information. By default, the information does not need to be encrypted.
ASSET_TAG_GROUP_ID¹⁸⁺	Type: Uint8[] Length: 7-127 bytes	No	Group to which the asset to be added belongs. By default, this parameter is not specified.

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.

For details about how to add an asset to a group, see Adding an Asset to a Group.

Add the dynamic library in the CMake script.

target_link_libraries(entry PUBLIC libasset_ndk.z.so)

Add an asset. “`c #include

#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.
  }

} “`