java - 从PKCS1 key 获取RSA公钥

我以以下格式获取了公共密钥，我需要使用Java来使用此密钥加密某些数据


  ----- BEGIN RSA公钥-----
  MIGJAoGBAKDZp / 3e4w1nJA / ImDMgaGowWfTnhlFkrvS86LBc6wh1 / zBRt51 / 2F / o / ZzaA5mZ
  nx5YMlhDOf3vHyzyO4KzYlG8md3RQU7eKQQDxgRfW1v0f7WVQoC2Dxbupyz0JVV4jQStYUYW
  ifGsh76wI3rkzlq3F2Ea / + jqMxX / AZOO30tBAgMBAAE =
  -----结束RSA公钥-----

最佳答案

您可以使用BouncyCastle库来实现此目的。您的密钥为PEM格式。要阅读它，您可以使用PEMParser：

private static PublicKey readPublicKey(String path) throws InvalidKeySpecException, NoSuchAlgorithmException, IOException {
    PEMParser pemParser = new PEMParser(new FileReader(path));
    Object object = pemParser.readObject();
    SubjectPublicKeyInfo subjectPublicKeyInfo = (SubjectPublicKeyInfo) object;

    RSAKeyParameters rsa = (RSAKeyParameters) PublicKeyFactory.createKey(subjectPublicKeyInfo);

    RSAPublicKeySpec rsaSpec = new RSAPublicKeySpec(rsa.getModulus(), rsa.getExponent());
    KeyFactory kf = KeyFactory.getInstance("RSA", new BouncyCastleProvider());
    return kf.generatePublic(rsaSpec);
}

然后使用此密钥进行加密：

PublicKey publicKey = readPublicKey("src/main/resources/key.pem");

String dataToEncrypt = "myMessage";
Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding", new BouncyCastleProvider());
cipher.init(Cipher.ENCRYPT_MODE, publicKey);
byte[] encrypted = cipher.doFinal(dataToEncrypt.getBytes(StandardCharsets.UTF_8));

经过以下版本测试：bcpkix-jdk15on和bcprov-jdk15on。