使用RSA非对称密钥（PKCS1模式）加解密

对应的算法规格请查看非对称密钥加解密算法规格：RSA。

加密

  1. 调用cryptoFramework.createAsyKeyGenerator、AsyKeyGenerator.generateKeyPair，生成RSA密钥类型为RSA1024、素数个数为2的非对称密钥对（KeyPair）。KeyPair对象中包括公钥PubKey、私钥PriKey。

    如何生成RSA非对称密钥对，开发者可参考下文示例，并结合非对称密钥生成和转换规格：RSA和随机生成非对称密钥对理解，参考文档与当前示例可能存在入参差异，请在阅读时注意区分。

  2. 调用cryptoFramework.createCipher，指定字符串参数'RSA1024|PKCS1'，创建非对称密钥类型为RSA1024、填充模式为PKCS1的Cipher实例，用于完成加解密操作。

  3. 调用Cipher.init，设置模式为加密（CryptoMode.ENCRYPT_MODE），指定加密密钥（KeyPair.PubKey），初始化加密Cipher实例。

    非对称密钥无加密参数，直接传入null。

  4. 调用Cipher.doFinal，传入明文，获取加密后的数据。

    • 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。
    • 当数据量较大时，可以多次调用doFinal，即分段加解密。

解密

  1. 由于RSA算法的Cipher实例不支持重复init操作，需要调用cryptoFramework.createCipher，重新生成Cipher实例。

  2. 调用Cipher.init，设置模式为解密（CryptoMode.DECRYPT_MODE），指定解密密钥（KeyPair.PriKey）初始化解密Cipher实例。PKCS1模式无加密参数，直接传入null。

  3. 调用Cipher.doFinal，传入密文，获取解密后的数据。

import cryptoFramework from '@ohos.security.cryptoFramework';
import buffer from '@ohos.buffer';
// 加密消息
async function encryptMessagePromise(publicKey: cryptoFramework.PubKey, plainText: cryptoFramework.DataBlob) {
  let cipher = cryptoFramework.createCipher('RSA1024|PKCS1');
  await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, publicKey, null);
  let encryptData = await cipher.doFinal(plainText);
  return encryptData;
}
// 解密消息
async function decryptMessagePromise(privateKey: cryptoFramework.PriKey, cipherText: cryptoFramework.DataBlob) {
  let decoder = cryptoFramework.createCipher('RSA1024|PKCS1');
  await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, privateKey, null);
  let decryptData = await decoder.doFinal(cipherText);
  return decryptData;
}
// 生成RSA密钥对
async function genKeyPairByData(pubKeyData: Uint8Array, priKeyData: Uint8Array) {
  let pubKeyBlob: cryptoFramework.DataBlob = { data: pubKeyData };
  let priKeyBlob: cryptoFramework.DataBlob = { data: priKeyData };
  let rsaGenerator = cryptoFramework.createAsyKeyGenerator('RSA1024');
  let keyPair = await rsaGenerator.convertKey(pubKeyBlob, priKeyBlob);
  console.info('convertKey success');
  return keyPair;
}
async function main() {
  let pkData = new Uint8Array([48, 129, 159, 48, 13, 6, 9, 42, 134, 72, 134, 247, 13, 1, 1, 1, 5, 0, 3, 129, 141, 0, 48, 129, 137, 2, 129, 129, 0, 197, 64, 10, 198, 14, 110, 65, 92, 206, 35, 28, 123, 153, 24, 134, 255, 145, 74, 42, 173, 40, 215, 146, 58, 143, 46, 10, 195, 154, 160, 69, 196, 220, 152, 179, 44, 111, 200, 84, 78, 215, 73, 210, 181, 12, 29, 70, 68, 36, 135, 153, 89, 230, 202, 130, 212, 111, 243, 234, 92, 131, 62, 145, 50, 73, 48, 104, 245, 46, 70, 45, 157, 147, 143, 140, 162, 156, 216, 220, 49, 121, 142, 194, 33, 223, 201, 0, 16, 163, 210, 240, 118, 92, 147, 121, 220, 17, 114, 24, 52, 125, 135, 176, 88, 21, 83, 86, 17, 156, 88, 250, 48, 79, 86, 128, 248, 105, 208, 133, 140, 13, 153, 164, 191, 136, 164, 44, 53, 2, 3, 1, 0, 1]);
  let skData = new Uint8Array([48, 130, 2, 119, 2, 1, 0, 48, 13, 6, 9, 42, 134, 72, 134, 247, 13, 1, 1, 1, 5, 0, 4, 130, 2, 97, 48, 130, 2, 93, 2, 1, 0, 2, 129, 129, 0, 197, 64, 10, 198, 14, 110, 65, 92, 206, 35, 28, 123, 153, 24, 134, 255, 145, 74, 42, 173, 40, 215, 146, 58, 143, 46, 10, 195, 154, 160, 69, 196, 220, 152, 179, 44, 111, 200, 84, 78, 215, 73, 210, 181, 12, 29, 70, 68, 36, 135, 153, 89, 230, 202, 130, 212, 111, 243, 234, 92, 131, 62, 145, 50, 73, 48, 104, 245, 46, 70, 45, 157, 147, 143, 140, 162, 156, 216, 220, 49, 121, 142, 194, 33, 223, 201, 0, 16, 163, 210, 240, 118, 92, 147, 121, 220, 17, 114, 24, 52, 125, 135, 176, 88, 21, 83, 86, 17, 156, 88, 250, 48, 79, 86, 128, 248, 105, 208, 133, 140, 13, 153, 164, 191, 136, 164, 44, 53, 2, 3, 1, 0, 1, 2, 129, 128, 70, 75, 184, 139, 53, 1, 94, 17, 240, 244, 218, 101, 193, 253, 215, 190, 164, 204, 197, 192, 200, 89, 107, 39, 171, 119, 65, 38, 204, 168, 105, 180, 234, 217, 16, 161, 185, 132, 175, 103, 25, 154, 153, 153, 36, 36, 26, 178, 150, 66, 45, 8, 185, 19, 90, 228, 210, 177, 30, 200, 177, 141, 78, 184, 248, 59, 113, 154, 145, 73, 160, 24, 73, 157, 86, 207, 186, 32, 95, 200, 106, 252, 107, 69, 170, 193, 216, 196, 181, 142, 74, 203, 15, 18, 89, 228, 152, 19, 239, 21, 233, 98, 121, 214, 57, 187, 111, 239, 223, 248, 199, 70, 223, 108, 108, 113, 234, 144, 155, 95, 246, 144, 244, 122, 39, 55, 127, 81, 2, 65, 0, 246, 96, 188, 0, 0, 104, 221, 105, 139, 144, 63, 175, 209, 87, 179, 162, 88, 192, 99, 82, 125, 53, 54, 48, 70, 245, 239, 37, 15, 242, 247, 84, 115, 187, 196, 95, 156, 40, 165, 60, 64, 102, 13, 229, 243, 2, 149, 0, 232, 226, 221, 192, 95, 11, 12, 208, 5, 181, 98, 62, 210, 190, 141, 235, 2, 65, 0, 204, 244, 34, 10, 105, 80, 76, 116, 163, 35, 231, 168, 187, 206, 189, 101, 215, 103, 80, 115, 86, 11, 34, 127, 203, 114, 84, 188, 121, 174, 169, 31, 142, 2, 182, 27, 140, 225, 157, 227, 71, 98, 15, 203, 187, 213, 5, 190, 20, 121, 8, 30, 193, 100, 232, 101, 141, 8, 124, 20, 29, 78, 6, 95, 2, 65, 0, 204, 43, 225, 224, 6, 118, 224, 117, 100, 200, 199, 94, 70, 23, 109, 175, 173, 232, 208, 230, 61, 8, 105, 189, 156, 48, 150, 91, 154, 89, 248, 136, 173, 215, 254, 166, 84, 220, 130, 1, 234, 68, 40, 100, 84, 251, 224, 202, 254, 51, 115, 28, 198, 38, 124, 25, 175, 129, 94, 199, 61, 17, 216, 189, 2, 64, 72, 230, 129, 129, 48, 138, 134, 87, 106, 123, 231, 247, 165, 173, 216, 194, 115, 198, 228, 223, 209, 120, 46, 114, 68, 92, 75, 117, 170, 214, 140, 131, 147, 208, 181, 19, 193, 157, 178, 186, 87, 246, 178, 101, 166, 79, 20, 54, 211, 51, 101, 199, 2, 197, 48, 192, 134, 84, 193, 69, 170, 82, 201, 131, 2, 65, 0, 213, 165, 55, 166, 131, 210, 195, 56, 250, 147, 195, 61, 205, 208, 189, 185, 40, 52, 50, 119, 137, 23, 246, 46, 220, 108, 52, 23, 152, 154, 94, 32, 144, 195, 184, 249, 21, 168, 12, 57, 222, 18, 60, 117, 81, 157, 72, 30, 155, 190, 165, 242, 228, 139, 240, 184, 145, 170, 103, 210, 160, 161, 135, 13]);
  let keyPair = await genKeyPairByData(pkData, skData);
  let pubKey = keyPair.pubKey;
  let priKey = keyPair.priKey;
  let message = 'This is a test';
  // 把字符串按utf-8解码为Uint8Array
  let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) };
  let encryptText = await encryptMessagePromise(pubKey, plainText);
  let decryptText = await decryptMessagePromise(priKey, encryptText);
  if (plainText.data.toString() === decryptText.data.toString()) {
    console.info('decrypt ok');
    // 把Uint8Array按utf-8编码为字符串
    let messageDecrypted = buffer.from(decryptText.data).toString('utf-8');
    console.info('decrypted result string:' + messageDecrypted);
  } else {
    console.error('decrypt failed');
  }
}