> The initial APIs of this module are supported since API version 8. Newly added APIs will be marked with a superscript to indicate their earliest API version.
Openharmony Universal KeyStore (HUKS) provides KeyStore (KS) capabilities for applications, including key management and key cryptography operations.
HUKS also provides APIs for applications to import or generate keys.
| options | [HuksOptions](#huksoptions) | Yes | Tags required for generating the key. |
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. |
| Promise\<[HuksResult](#huksresult)> | Promise used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. |
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. |
| Promise\<[HuksResult](#huksresult)> | Promise used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. |
| keyAlias | string | Yes | Key alias, which is used to hold the key pair.|
| options | [HuksOptions](#huksoptions) | Yes | Tags required for the import and key pair to import.|
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. |
| Promise\<[HuksResult](#huksresult)> | Promise used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. |
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**. **outData** contains the public key exported. |
| Promise\<[HuksResult](#huksresult)> | Promise used to return the result. If the operation is successful, **HUKS_SUCCESS** will be returned. If the operation fails, an error code will be returned. For details about the error codes, see **HuksResult**.<br/>**outData** contains the public key exported. |
| callback | AsyncCallback\<[HuksResult](#huksresult)> | Yes | Callback used to return the result. In **errorCode**, **HUKS_SUCCESS** will be returned if the operation is successful; an error code will be returned otherwise. |
| Promise\<[HuksResult](#huksoptions)> | Promise used to return the result. In **errorCode**, **HUKS_SUCCESS** will be returned if the operation is successful; an error code will be returned otherwise. For details about the error codes, see **HuksResult**. |
Openharmony Universal KeyStore (HUKS) provides KeyStore (KS) capabilities for applications, including key management and key cryptography operations. HUKS also provides APIs for applications to import or generate keys.
| function generateKey(keyAlias: string, options: HuksOptions, callback: AsyncCallback<HksResult>) : void; | Generates a key or key pair. This method uses an asynchronous callback to return the result. |
| function generateKey(keyAlias: string, options: HuksOptions) : Promise<HuksResult>; | Generates a key or key pair. This method uses a promise to return the result. |
| function exportKey(keyAlias: string, options: HuksOptions, callback: AsyncCallback<HuksResult>) : void; | Exports the public key. This method uses an asynchronous callback to return the result. |
| function exportKey(keyAlias: string, options: HuksOptions) : Promise<HuksResult>; | Exports the public key. This method uses a promise to return the result. |
| function isKeyExist(keyAlias: string, options: HuksOptions, callback: AsyncCallback<boolean>) : void; | Check whether a key exists. This method uses an asynchronous callback to return the result.|
| function isKeyExist(keyAlias: string, options: HuksOptions) : Promise<boolean>; | Check whether a key exists. This method uses a promise to return the result.|
| function deleteKey(keyAlias: string, options: HuksOptions, callback: AsyncCallback<HuksResult>) : void; | Deletes a key. This method uses an asynchronous callback to return the result. |
| function deleteKey(keyAlias: string, options: HuksOptions) : Promise<HuksResult>; | Deletes a key. This method uses a promise to return the result. |
## How to Develop
1. Import the HUKS module.
```js
importhuksfrom'@ohos.security.huks'
```
2. Call **generateKey()** to generate a key pair.
**keyAlias** indicates the alias of the key generated. **options** indicates the parameters used for generating the key. Set **options** based on actual situation.
The value returned indicates whether the key is successfully generated.
```js
varalias='testAlias';
varproperties=newArray();
properties[0]={
tag:huks.HuksTag.HUKS_TAG_ALGORITHM,
value:huks.HuksKeyAlg.HUKS_ALG_ECC
};
properties[1]={
tag:huks.HuksTag.HUKS_TAG_KEY_SIZE,
value:huks.HuksKeySize.HUKS_ECC_KEY_SIZE_224
};
properties[2]={
tag:huks.HuksTag.HUKS_TAG_PURPOSE,
value:huks.HuksKeyPurpose.HUKS_KEY_PURPOSE_AGREE
};
properties[3]={
tag:huks.HuksTag.HUKS_TAG_DIGEST,
value:huks.HuksKeyDigest.HUKS_DIGEST_NONE
};
varoptions={
properties:properties
}
varresultA=huks.generateKey(alias,options);
```
3. Call **Init()** to initialize the key.
**Alias** indicates the alias of the key to initialize, and **options** indicates the parameters used for initializing the key.
The value returned indicates whether the **Init** operation is successful.
Openharmony Universal KeyStore (HUKS) provides KeyStore (KS) capabilities for applications, including key management and key cryptography operations. HUKS also provides APIs for applications to import or generate keys.
### Basic Concepts
- HUKS provides key management functions, including encryption and decryption, signing and signature verification, key agreement and derivation, and Hash-based Message Authentication Code (HMAC) calculation.
- HUKS supports the following algorithms: AES and RSA in encryption and decryption, RSA, ECC, DSA, and ED25519 in signing and signature verification, PBKDF2 in key derivation, and DH, ECDH, and X25519 in key agreement.
- HUKS uses the OpenSSL and Mbed TLS algorithm libraries.
### Working Principles
HUKS manages keys through the following operations:
-**Init**: reads the key, creates a session ID, and returns the session ID to the caller.
-**Update**: updates data by segment based on the session ID obtained.
-**Finish**: processes all data transferred to HUKS and then releases resources.
>**NOTICE**:<br/>If an error occurs in the **Init**, **Update**, or **Finish** operation, you must invoke the **Abort** operation to terminate the use of the key.
