如何使用AES ECB 加密方式?

import cryptoFramework from '@ohos.security.cryptoFramework'; 
import buffer from '@ohos.buffer'; 
import util from '@ohos.util'; 
 
export class  RSA { 
  public static async add(str: string, publicKey: string): Promise<string> { 
    let result = ``; 
    try { 
      let base = new util.Base64Helper(); 
      let asyKeyGenerator = cryptoFramework.createAsyKeyGenerator("RSA1024"); 
      let cipher = cryptoFramework.createCipher("RSA|ECB|PKCS1"); //创建一个 Cipher (加密)对象 
      //引入外部的公钥加密 
 
      let publicKeyDataBlob = {data: base.decodeSync(publicKey)}; 
      let keyGenPromise: cryptoFramework.KeyPair = await asyKeyGenerator.convertKey(publicKeyDataBlob, null); 
      await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, keyGenPromise.pubKey, null); 
      let put: cryptoFramework.DataBlob = { data: RSA.stringToUint8Array(str) }; 
      const finalRes = await cipher.doFinal(put) 
      result = base.encodeToStringSync(finalRes.data); 
    } catch (err) { 
      console.log(err.message) 
    } 
    return result; 
  } 
 
  static stringToUint8Array(str: string): Uint8Array { 
    return new Uint8Array(buffer.from(str, 'utf8').buffer); 
  } 
}