HarmonyOS sm4加密有无cbc方式

SM4有cbc方式，参考以下规格文档：https://gitee.com/openharmony/docs/blob/master/zh-cn/application-dev/security/CryptoArchitectureKit/crypto-sym-encrypt-decrypt-spec.md#sm4

async function SM4ED(plainText: string) {
  let sm4Generator = cryptoFramework.createSymKeyGenerator('SM4_128');
  let cipher = cryptoFramework.createCipher("SM4_128|CBC|PKCS7");
  let decoder = cryptoFramework.createCipher("SM4_128|CBC|PKCS7");
  let input: cryptoFramework.DataBlob = { data: stringToUint8Array(plainText) };

  let keydata: cryptoFramework.DataBlob = { data: stringToUint8Array('yc1436w86vhys51r') }; //密钥

  let ivdata: cryptoFramework.DataBlob = { data: stringToUint8Array('43pr5253zf5mm7jd') }; //偏移
  let iv: cryptoFramework.IvParamsSpec = { iv: ivdata, algName: 'IvParamsSpec' } //cbc模式的参数 不需要可以不写
  let key: cryptoFramework.SymKey

  try {
    key = await sm4Generator.convertKey(keydata);
    // 加密
    // 最后一个参数是偏移量的设置，如果没有则为null，下面解密同理
    await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, key, null);
    let cipherData = await cipher.doFinal(input)

    //解密
    await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, key, null);
    let result = await decoder.doFinal(cipherData);

    //解密后的明文
    let str = uint8ArrayToString(result.data)
    AlertDialog.show({ message: "decrypt success ==>" + str })
  } catch (err) {
    console.error(err)
  }
}