HarmonyOS AES目前加密成功，但是解密时出现crash

@Entry
@Component
struct Index {
  aboutToAppear(): void {
    AesUtils.encryptCBC('测试hello', 'newaircloud_vjow9Dej#JDj4[oIDF', (str: string) => {
      this.str = str
    })
  }

  @State str?: string = ''
  @State str2?: string = ''

  build() {
    Column() {
      Text('AES加密：' + this.str)
        .height(100)
        .backgroundColor(Color.Pink)
        .onClick(() => {
          AesUtils.encryptCBC('测试hello', 'newaircloud_vjow9Dej#JDj4[oIDF', (str: string) => {
            this.str = str
          })
        })

      Text('AES解密：' + this.str2)
        .height(100)
        .backgroundColor(Color.Pink)
        .onClick(() => {
          AesUtils.decryptCBC(this.str!, 'newaircloud_vjow9Dej#JDj4[oIDF', (str: string) => {
            this.str2 = str
          })
        })

    }
  }
}

以下是工具类代码：

export class AesUtils {
  static async encryptCBC(message: string, pk: string, callBack: Function) {
    try {
      let base64 = new util.Base64Helper();
      let dataUnit = AesUtils.doMdBySync(pk)

      let symKey = await AesUtils.genSymKeyByData(dataUnit);
      let newBuf = buffer.from(buffer.from(message, 'utf-8').buffer);
      let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(newBuf.buffer) };
      let encryptText = await AesUtils.encryptMessagePromise(symKey, plainText);
      let encrypt = base64.encodeToStringSync(encryptText.data)
      if (callBack) {
        callBack(encrypt)
      }

    } catch (error) {
      console.error(JSON.stringify(error));
      if (callBack) {
        let str = JSON.stringify(error)
        callBack(str)
      }
    }
  }

  public static async decryptCBC(message: string, pk: string, callBack: Function) {
    try {
      let dataUnit = AesUtils.doMdBySync(pk)

      let symKey = await AesUtils.genSymKeyByData(dataUnit);
      let newBuf = buffer.from(buffer.from(message, 'utf-8').buffer);
      let encryptText: cryptoFramework.DataBlob = { data: new Uint8Array(newBuf.buffer) };

      let decryptText = await AesUtils.decryptMessagePromise(symKey, encryptText);
      if (decryptText.data.toString()) {
        let decrypt = buffer.from(decryptText.data).toString('utf-8')
        if (callBack) {
          callBack(decrypt)
        }
      } else {
        if (callBack) {
          callBack('decrypt failed')
        }
      }

    } catch (error) {
      if (callBack) {
        let str = JSON.stringify(error)
        callBack('decrypt failed' + str)
      }
    }
  }

  // key生成
  private static async genSymKeyByData(symKeyData: Uint8Array) {
    let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
    let aesGenerator = cryptoFramework.createSymKeyGenerator('AES256');
    let symKey = await aesGenerator.convertKey(symKeyBlob);
    console.info('convertKey success:');
    return symKey;
  }

  // 加密消息
  private static async encryptMessagePromise(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
    let cipher = cryptoFramework.createCipher('AES256|CBC|PKCS7');
    let iv = AesUtils.genIvParamsSpec();
    await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, iv);
    let cipherData = await cipher.doFinal(plainText);
    return cipherData;
  }

  // 解密消息
  private static async decryptMessagePromise(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
    let decoder = cryptoFramework.createCipher('AES256|CBC|PKCS7');
    let iv = AesUtils.genIvParamsSpec();
    await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, iv);
    let decryptData = await decoder.doFinal(cipherText);
    return decryptData;
  }

  private static doMdBySync(key: string): Uint8Array {
    let mdAlgName = 'SHA256'; // 摘要算法名
    let md = cryptoFramework.createMd(mdAlgName);
    let firstArray = new Uint8Array(buffer.from(key, 'utf-8').buffer)
    md.updateSync({ data: firstArray });
    let mdResult = md.digestSync();
    let data = new util.Base64Helper().encodeToStringSync(mdResult.data)
    console.info('[Sync]:Md result base64:' + data);
    let hex = buffer.from(mdResult.data).toString('hex')
    console.info('Md result hex:' + hex);
    let mdLen = md.getMdLength();
    console.info("md len: " + mdLen);

    return mdResult.data
  }

  // iv生成
  private static genIvParamsSpec(): cryptoFramework.IvParamsSpec {
    let arr = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]; // 16 bytes
    let dataIv = new Uint8Array(arr);
    let ivBlob: cryptoFramework.DataBlob = { data: dataIv };
    let ivParamsSpec: cryptoFramework.IvParamsSpec = {
      algName: "IvParamsSpec",
      iv: ivBlob
    };
    return ivParamsSpec;
  }
}