使用ChaCha20对称密钥加解密(ArkTS)

从API22开始，算法库支持该算法。

对应的算法规格请查看对称密钥加解密算法规格：ChaCha20。

开发步骤

创建对象

调用cryptoFramework.createSymKeyGenerator、SymKeyGenerator.generateSymKey，生成密钥算法为ChaCha20的对称密钥（SymKey）。

如何生成ChaCha20对称密钥，开发者可参考下文示例，并结合对称密钥生成和转换规格：ChaCha20和随机生成对称密钥理解。参考文档与示例可能存在入参差异，请注意区分。

加密

调用cryptoFramework.createCipher，指定字符串参数'ChaCha20'，创建对称密钥的Cipher实例，用于完成加密操作。
调用Cipher.init，设置模式为加密（cryptoFramework.CryptoMode.ENCRYPT_MODE），指定加密密钥（SymKey）和对应的加密参数（IvParamsSpec），初始化加密Cipher实例。
调用Cipher.update，更新数据（明文）。
调用Cipher.doFinal，获取加密后的数据。

由于已使用update传入数据，此处data传入null。

doFinal输出结果可能为null，在访问具体数据前，需要先判断结果是否为null，避免产生异常。

解密

调用cryptoFramework.createCipher，指定字符串参数'ChaCha20'，创建对称密钥的Cipher实例，用于完成解密操作。
调用Cipher.init，设置模式为解密（cryptoFramework.CryptoMode.DECRYPT_MODE），指定解密密钥（SymKey）和对应的解密参数（IvParamsSpec），初始化解密Cipher实例。
调用Cipher.update，更新数据（密文）。
调用Cipher.doFinal，获取解密后的数据。

异步方法示例：

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

function generateRandom(len: number) {
  let rand = cryptoFramework.createRandom();
  let generateRandSync = rand.generateRandomSync(len);
  return generateRandSync;
}

function genIvParamsSpec() {
  let ivBlob = generateRandom(16);
  let ivParamsSpec: cryptoFramework.IvParamsSpec = {
    algName: 'IvParamsSpec',
    iv: ivBlob
  };
  return ivParamsSpec;
}
let ivSpec = genIvParamsSpec();

// 加密消息。
async function encryptMessagePromise(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
  let cipher = cryptoFramework.createCipher('ChaCha20');
  await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, ivSpec);
  let encryptData = await cipher.doFinal(plainText);
  return encryptData;
}

// 解密消息。
async function decryptMessagePromise(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
  let decoder = cryptoFramework.createCipher('ChaCha20');
  await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, ivSpec);
  let decryptData = await decoder.doFinal(cipherText);
  return decryptData;
}

async function genSymKeyByData(symKeyData: Uint8Array) {
  let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
  let chacha20Generator = cryptoFramework.createSymKeyGenerator('ChaCha20');
  let symKey = await chacha20Generator.convertKey(symKeyBlob);
  console.info('convertKey result: success.');
  return symKey;
}

async function main() {
  try {
    let keyData = new Uint8Array([83, 217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159, 83,
      217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159]);
    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 = await encryptMessagePromise(symKey, plainText);
    let decryptText = await decryptMessagePromise(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(`decrypt failed: errCode: ${error.code}, message: ${error.message}`);
  }
}

同步方法示例：

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

function generateRandom(len: number) {
  let rand = cryptoFramework.createRandom();
  let generateRandSync = rand.generateRandomSync(len);
  return generateRandSync;
}

function genIvParamsSpec() {
  let ivBlob = generateRandom(16);
  let ivParamsSpec: cryptoFramework.IvParamsSpec = {
    algName: 'IvParamsSpec',
    iv: ivBlob
  };
  return ivParamsSpec;
}

let ivSpec = genIvParamsSpec();

// 加密消息。
function encryptMessage(symKey: cryptoFramework.SymKey, plainText: cryptoFramework.DataBlob) {
  let cipher = cryptoFramework.createCipher('ChaCha20');
  cipher.initSync(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, ivSpec);
  let encryptData = cipher.doFinalSync(plainText);
  return encryptData;
}

// 解密消息。
function decryptMessage(symKey: cryptoFramework.SymKey, cipherText: cryptoFramework.DataBlob) {
  let decoder = cryptoFramework.createCipher('ChaCha20');
  decoder.initSync(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, ivSpec);
  let decryptData = decoder.updateSync(cipherText);
  return decryptData;
}

function genSymKeyByData(symKeyData: Uint8Array) {
  let symKeyBlob: cryptoFramework.DataBlob = { data: symKeyData };
  let chacha20Generator = cryptoFramework.createSymKeyGenerator('ChaCha20');
  let symKey = chacha20Generator.convertKeySync(symKeyBlob);
  console.info('convertKeySync result: success.');
  return symKey;
}

function main() {
  try {
    let keyData = new Uint8Array([83, 217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159, 83,
      217, 231, 76, 28, 113, 23, 219, 250, 71, 209, 210, 205, 97, 32, 159]);
    let symKey = 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(`decrypt failed: errCode: ${error.code}, message: ${error.message}`);
  }
}

开发步骤​

开发步骤