Access Control by Device and Data Level (C/C++)

When to Use

The access control mechanism ensures secure data storage and sync across devices. When creating a database, you need to correctly set the security label based on the specifications to ensure the consistency between the database content and data labels.

Currently, only RDB stores (C/C++) support hierarchical access control.

Basic Concepts

Distributed data management implements access control based on data security labels and device security levels.

A higher data security label and device security level indicate stricter encryption and access control measures and higher data security.

Data Security Labels

The data can be rated into four security levels as below. For details, see OH_Rdb_SecurityLevel.

Risk Level	Security Level	Definition	Example
Critical	S4	Special data types defined by industry laws and regulations, involving the most private individual information or data that may cause severe adverse impact on an individual or group once disclosed, tampered with, corrupted, or destroyed.	Political opinions, religious and philosophical belief, trade union membership, genetic data, biological information, health and sexual life status, sexual orientation, device authentication, and personal credit card information
High	S3	Data that may cause critical adverse impact on an individual or group once disclosed, tampered with, corrupted, or destroyed.	Individual real-time precise positioning information and movement trajectory
Moderate	S2	Data that may cause major adverse impact on an individual or group once disclosed, tampered with, corrupted, or destroyed.	Detailed addresses and nicknames of individuals
Low	S1	Data that may cause minor adverse impact on an individual or group once disclosed, tampered with, corrupted, or destroyed.	Gender, nationality, and user application records

Device Security Levels

Device security levels are classified into SL1 to SL5 based on devices' security capabilities, such as whether a Trusted Execution Environment (TEE) or a secure storage chip is available. For example, the development boards RK3568 and Hi3516 are SL1 (lower security) devices, and tablets are SL4 (higher security) devices.

During device networking, you can run the hidumper -s 3511 command to query the device security level. If no result is displayed, run the service_control start dslm_service command to start the corresponding process and then run the hidumper command to query the security level. The following example shows how to query the security level of the RK3568 device:

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Access Control Mechanism in Cross-Device Sync

In cross-device data sync, data access is controlled based on the device security level and data security labels. In principle, data can be synced only to the devices whose data security labels are not higher than the device's security level. The access control matrix is as follows.

Device Security Level	Data Security Labels of the Synchronization Device
SL1	S1
SL2	S1 to S2
SL3	S1 to S3
SL4	S1 to S4
SL5	S1 to S4

The security level of development boards RK3568 and Hi3516 is SL1. The database with data security label S1 can be synced with RK3568 and Hi3516, but the databases with labels S2–S4 cannot.

How to Develop

When creating an RDB store, call the OH_Rdb_SetSecurityLevel API to specify the security level of the RDB store. The following example shows how to create an RDB store with security level of SL3.

Add the following library to CMakeLists.txt.
```
libnative_rdb_ndk.z.so
```

Include header files.

#include <cstring>
#include "database/rdb/relational_store.h"
#include "hilog/log.h"

napi_init.cpp

Call OH_Rdb_SetSecurityLevel to set the database security level.

OH_Rdb_ConfigV2 *config = OH_Rdb_CreateConfig();
OH_Rdb_SetDatabaseDir(config, "/data/storage/el2/database");
OH_Rdb_SetStoreName(config, "RdbTest.db");
OH_Rdb_SetBundleName(config, "com.example.nativedemo");
OH_Rdb_SetModuleName(config, "entry");
// Set the security level of the database.
OH_Rdb_SetSecurityLevel(config, OH_Rdb_SecurityLevel::S3);
OH_Rdb_SetEncrypted(config, false);
OH_Rdb_SetArea(config, RDB_SECURITY_AREA_EL2);
    
int errCode = 0;
OH_Rdb_Store *store_ = OH_Rdb_CreateOrOpen(config, &errCode);
OH_Rdb_CloseStore(store_);
store_ = nullptr;
OH_Rdb_DestroyConfig(config);
config = nullptr;

napi_init.cpp