AES加解密可以参考原生的AES加解密，参考链接：https://developer.huawei.com/consumer/cn/doc/harmonyos-guides-V5/crypto-aes-sym-encrypt-decrypt-ecb-V5

import { cryptoFramework } from '@kit.CryptoArchitectureKit';
import { buffer, util } from '@kit.ArkTS';

// 加密消息
function encryptMessage(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
  let cipher = cryptoFramework.createCipher('AES128|ECB|PKCS5');
  cipher.initSync(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, null);
  let cipherData = cipher.doFinalSync(plainText);
  return cipherData;
}

// 解密消息
function decryptMessage(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
  let decoder = cryptoFramework.createCipher('AES128|ECB|PKCS5');
  decoder.initSync(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, null);
  let decryptData = decoder.doFinalSync(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 success');
  return symKey;
}

async function main() {
  try {
    let keystr = '密钥'
    let keyData = stringToUint8Array(keystr)
    let symKey = await genSymKeyByData(keyData);
    let message = "This is a test";
    let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) };
    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 ECB "${error}", error code: ${error.code}`);
  }
}

@Entry
@Component
struct AESDemo {
  @State message: string = 'Hello World';

  aboutToAppear(): void {
    main()
  }

  build() {
    RelativeContainer() {
      Text(this.message)
        .id('AESDemoHelloWorld')
        .fontSize(50)
        .fontWeight(FontWeight.Bold)
        .alignRules({
          center: { anchor: '__container__', align: VerticalAlign.Center },
          middle: { anchor: '__container__', align: HorizontalAlign.Center }
        })
    }
    .height('100%')
    .width('100%')
  }
}

function stringToUint8Array(str: string) {
  return new Uint8Array(buffer.from(str, 'utf-8').buffer);
}