# 使用AES-WRAP算法对对称密钥加解密(ArkTS)

从API版本22开始，算法库支持使用该算法进行加密和解密操作。

对应的算法规格请参见[AES-WRAP加解密算法规格](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/crypto-encryption-decryption#aes-wrap)。

**加密**

1. 调用[cryptoFramework.createSymKeyGenerator](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#cryptoframeworkcreatesymkeygenerator)、[SymKeyGenerator.convertKey](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#convertkey-1)，生成密钥算法为AES、密钥长度为128位的对称密钥（SymKey）。

   如何生成AES对称密钥，开发者可参考下文示例，并结合[对称密钥生成和转换规格：AES](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/crypto-key-generation-conversion#aes)和[随机生成对称密钥](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/crypto-generate-sym-key-randomly)理解，参考文档与当前示例可能存在入参差异，请在阅读时注意区分。
2. 调用[cryptoFramework.createCipher](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#cryptoframeworkcreatecipher)，指定字符串参数'AES128-WRAP'，创建类型为AES128-WRAP的Cipher实例，用于完成加密操作。

3. 调用[Cipher.init](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#init-1)，设置模式为加密（cryptoFramework.CryptoMode.ENCRYPT_MODE），指定加密密钥（SymKey）和对应的加密参数（IvParamsSpec），初始化加密Cipher实例。

4. 当加密内容长度较短时，可以直接调用 [Cipher.doFinal](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#dofinal-1) 而无需调用update，以获取加密后的数据。

**解密**

1. 调用[cryptoFramework.createCipher](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#cryptoframeworkcreatecipher)，指定字符串参数'AES128-WRAP'，创建类型为AES128-WRAP的Cipher实例，用于完成解密操作。

2. 调用[Cipher.init](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#init-1)，设置模式为解密（cryptoFramework.CryptoMode.DECRYPT_MODE），指定解密密钥（SymKey）和对应的解密参数（IvParamsSpec），初始化解密Cipher实例。

3. 当解密内容长度较短时，可以省略调用update，直接调用[Cipher.doFinal](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/js-apis-cryptoframework#dofinal-1)，获取解密后的数据。

* 异步方法示例：

  ```TypeScript
  import { cryptoFramework } from '@kit.CryptoArchitectureKit';
  import { buffer } from '@kit.ArkTS';

  function generateRandom(len: number) {
    let rand = cryptoFramework.createRandom();
    let generateRandSync = rand.generateRandomSync(len);
    return generateRandSync;
  }

  function genIvParamsSpec() {
    let ivBlob = generateRandom(8);
    let ivParamsSpec: cryptoFramework.IvParamsSpec = {
      algName: 'IvParamsSpec',
      iv: ivBlob
    };
    return ivParamsSpec;
  }
  let iv = genIvParamsSpec();
  // 加密消息。
  async function encryptMessagePromise(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
    let cipher = cryptoFramework.createCipher('AES128-WRAP');
    await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, iv);
    let cipherData = await cipher.doFinal(plainText);
    return cipherData;
  }
  // 解密消息。
  async function decryptMessagePromise(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
    let decoder = cryptoFramework.createCipher('AES128-WRAP');
    await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, iv);
    let decryptData = await decoder.doFinal(cipherText);
    return decryptData;
  }

  async function genSymKeyByData(symKeyData: Uint8Array) {
    let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
    let aesGenerator = cryptoFramework.createSymKeyGenerator('AES128');
    let symKey = await aesGenerator.convertKey(symKeyBlob);
    console.info('convertKey result: success.');
    return symKey;
  }

  async function aesWrapTest() {
    try {
      let keyData = new Uint8Array([83, 217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159]);
      let symKey = await genSymKeyByData(keyData);
      let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(keyData)};
      let encryptText = await encryptMessagePromise(symKey, plainText);
      let decryptText = await decryptMessagePromise(symKey, encryptText);
      if (plainText.data.toString() === decryptText.data.toString()) {
        console.info('decrypt ok.');
        console.info('decrypt plainText: ' + buffer.from(decryptText.data).toString('utf-8'));
      } else {
        console.error('decrypt failed.');
      }
    } catch (error) {
      console.error(`AES Wrap failed: errCode: ${error.code}, message: ${error.message}`);
    }
  }
  ```

* 同步方法示例：

  ```TypeScript
  import { cryptoFramework } from '@kit.CryptoArchitectureKit';
  import { buffer } from '@kit.ArkTS';

  function generateRandom(len: number) {
    let rand = cryptoFramework.createRandom();
    let generateRandSync = rand.generateRandomSync(len);
    return generateRandSync;
  }

  function genIvParamsSpec() {
    let ivBlob = generateRandom(8);
    let ivParamsSpec: cryptoFramework.IvParamsSpec = {
      algName: 'IvParamsSpec',
      iv: ivBlob
    };
    return ivParamsSpec;
  }
  let iv = genIvParamsSpec();
  // 加密消息。
  function encryptMessage(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
    let cipher = cryptoFramework.createCipher('AES128-WRAP');
    cipher.initSync(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, iv);
    let cipherData = cipher.doFinalSync(plainText);
    return cipherData;
  }
  // 解密消息。
  function decryptMessage(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
    let decoder = cryptoFramework.createCipher('AES128-WRAP');
    decoder.initSync(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, iv);
    let decryptData = decoder.doFinalSync(cipherText);
    return decryptData;
  }

  function genSymKeyByData(symKeyData: Uint8Array) {
    let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
    let aesGenerator = cryptoFramework.createSymKeyGenerator('AES128');
    let symKey = aesGenerator.convertKeySync(symKeyBlob);
    console.info('convertKeySync result: success.');
    return symKey;
  }

  function main() {
    try {
      let keyData = new Uint8Array([83, 217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159]);
      let symKey = genSymKeyByData(keyData);
      let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(keyData)};
      let encryptText = encryptMessage(symKey, plainText);
      let decryptText = decryptMessage(symKey, encryptText);
      if (plainText.data.toString() === decryptText.data.toString()) {
        console.info('decrypt ok.');
        console.info('decrypt plainText: ' + buffer.from(decryptText.data).toString('utf-8'));
      } else {
        console.error('decrypt failed.');
      }
    } catch (error) {
      console.error(`AES Wrap failed: errCode: ${error.code}, message: ${error.message}`);
    }
  }
  ```