HarmonyOS 异或算法

参考示例：

import util from '@ohos.util';

export async function xor_test() {
  let test_data = '123456'
  let key = '8888'

  let test_data_u = stringToUint8Array(test_data)
  let key_u = stringToUint8Array(key)
  let key2_u: Uint8Array = new Uint8Array();
  if (key_u.length < test_data_u.length) {
    //前面补齐0
    for (let i = 0; i < test_data_u.length - key_u.length; i++) {
      key2_u[i] = 0
    }
    for (let i = 0; i < key_u.length; i++) {
      key2_u[i] = key_u[i]
    }
  }
  console.info("====source:" + test_data)
  //异或加密
  for (let i = 0; i < test_data_u.length; i++) {
    test_data_u[i] ^= key2_u[i]
  }
  console.info("====xor encrypt:" + test_data_u)
  //异或解密
  for (let i = 0; i < test_data_u.length; i++) {
    test_data_u[i] ^= key2_u[i]
  }
  console.info("====xor decrypt:" + uint8ArrayToString(test_data_u))
}

//string转Uint8Array
function stringToUint8Array(str: string): Uint8Array {
  try {
    let textEncoder = new util.TextEncoder("utf-8");
    let array: Uint8Array = textEncoder.encodeInto(str);
    return array
  } catch (err) {
    console.error(`stringToUint8Array = ${err}`)
    return new Uint8Array()
  }
}

//Uint8Array转string
function uint8ArrayToString(arr:Uint8Array):string{
  let str = ''
  if (arr && arr.length > 0) {
    try {
      let textDecode = util.TextDecoder.create('utf-8')
      str = textDecode.decodeWithStream(arr)
    } catch (err) {
    }
  }
  return str
}

@Entry
@Component
struct Page20 {
  @State message: string = 'Hello World';
  aboutToAppear(): void {
    xor_test()
  }
  build() {
    Row() {
      Column() {
        Text(this.message)
          .fontSize(50)
          .fontWeight(FontWeight.Bold)
      }
      .width('100%')
    }
    .height('100%')
  }
}