基于3DES实现DES

最近在绿泡泡群，有开发者问到一个问题，在ArkTs里，使用 cryptoJs.库对字符串加密后的结果别的程序生成的不一致，兴趣之余做了个复测确实不一致，翻阅鸿蒙社区的示例工程，和API文档，只有3DES的实现，以学习研究为目的，我实现了一个给这位开发者使用，反馈效果还不错，特分享下。

发现问题：

解决问题（CryptoUtil.ets）：

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

export class CryptoUtil {
  private key: cryptoFramework.SymKey;
  private iv: cryptoFramework.IvParamsSpec;
  private cipher: cryptoFramework.Cipher;
  private decoder: cryptoFramework.Cipher;
  private static instance: CryptoUtil;

  private constructor(key: string, iv: string) {
    this.key = this.genSymKeyByData(key);
    this.iv = this.genIvParamsSpec(iv);
    this.cipher = cryptoFramework.createCipher('3DES192|CBC|PKCS7');
    this.decoder = cryptoFramework.createCipher('3DES192|CBC|PKCS7');
  }

  public static getInstance(key: string, iv: string): CryptoUtil {

    if (!CryptoUtil.instance) {
      CryptoUtil.instance = new CryptoUtil(key, iv)
    }

    return CryptoUtil.instance;
  }

  // 加密消息
  public encryptMessageWithDESCBC(message: string): string {

    if(message.length==0){
      return "";
    }

    let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) };
    this.cipher.initSync(cryptoFramework.CryptoMode.ENCRYPT_MODE, this.key, this.iv);
    let encryptData = this.cipher.doFinalSync(plainText);

    let base = new util.Base64Helper();
    return base.encodeToStringSync(encryptData.data);

  }

  // 解密消息
  public decryptMessageWithDESCBC(message:string|undefined): string {

    if(message==undefined|| message.length==0){
      return "";
    }

    this.decoder.initSync(cryptoFramework.CryptoMode.DECRYPT_MODE, this.key, this.iv);

    let base = new util.Base64Helper();
    let plainText: cryptoFramework.DataBlob = { data: base.decodeSync(message) };
    let decryptData = this.decoder.doFinalSync(plainText);

    if (decryptData.data.toString() === decryptData.data.toString()) {
      let textDecoder = util.TextDecoder.create('utf-8');
      return textDecoder.decodeWithStream(decryptData.data);
    } else {
      console.error('decrypt failed');
      return "";
    }
  }

  private genSymKeyByData(key: string) {

    key = key.substring(0, 8);
    let keyData = new Uint8Array(24);
    keyData.set(new util.TextEncoder().encodeInto(key))

    let symKeyBlob: cryptoFramework.DataBlob = { data: keyData };
    let symGenerator = cryptoFramework.createSymKeyGenerator('3DES192');
    let symKey = symGenerator.convertKeySync(symKeyBlob);

    return symKey;

  }

  private genIvParamsSpec(iv: string): cryptoFramework.IvParamsSpec {

    iv = iv.substring(0, 8);
    let dataIv = new Uint8Array(24);
    dataIv.set(new util.TextEncoder().encodeInto(iv))
    let ivBlob: cryptoFramework.DataBlob = { data: dataIv };
    let ivParamsSpec: cryptoFramework.IvParamsSpec = {
      algName: 'IvParamsSpec',
      iv: ivBlob
    };
    return ivParamsSpec;
  }
}

验证效果：

在线工具的结果：

Yes！！！