static async decryptData(originData:Uint8Array,keyData:Uint8Array,ivData:Uint8Array):Promise<Uint8Array|null>{
    let callData:Uint8Array|null = null;
    if (originData.length>0 && keyData.length>0) {
      try {
        let cipher = cryptoFramework.createCipher('AES256|CBC|NoPadding');
        let syKey =await genSymKeyByData(keyData);
        let ivParams:cryptoFramework.IvParamsSpec =
          {iv:{ data : ivData},algName:'IvParamsSpec' };
        await cipher.init(cryptoFramework.CryptoMode.DECRYPT_MODE,syKey,ivParams)
        console.log('decrypt cipher.init  succ');
        let updateCipher = await cipher.update({data:originData})
        if (updateCipher != null && updateCipher.data != null) {
          callData = updateCipher.data;
        }
        // let data =await cipher.doFinal(null);
        // let data = await cipher.doFinal({data:originData});
        // if (data != null && data.data != null) {
        //   console.log('decrypt doFinal succ：' + data.data.length);
        //   callData = data.data;
        // }else {
        //   console.log('decrypt doFinal err: ');
        // }
      } catch (err) {
        console.log('decrypt ：error ' +(err as BusinessError ).code+(err as BusinessError ).message);
      }
    }
    return callData;
  }
  static  async genSymKeyByData(symKeyData: Uint8Array):Promise<cryptoFramework.SymKey> {
    let symKeyBlob: cryptoFramework.DataBlob = { 'AES256' };
    let aesGenerator = cryptoFramework.createSymKeyGenerator(ReaderUtil.generatorAlgName);
    let symKey = await aesGenerator.convertKey(symKeyBlob);
    console.info('convertKey success symKey     '+symKey.getEncoded().data.toString());
    console.info('convertKey success symKeyData '+symKeyData.toString());
    return symKey;
  }

使用cipher.doFinal一直错误，最后专用cipher.update；
AES256对应的是32位的key；
AES128对应的是16位的key。

参考鸿蒙文档