从 PKCS1 密钥获取 RSA public 密钥

Question

我得到以下格式的 public 密钥，我需要使用 java 使用此密钥加密一些数据

-----BEGIN RSA PUBLIC KEY----- MIGJAoGBAKDZp/3e4w1nJA/ImDMgaGowWfTnhlFkrvS86LBc6wh1/zBRt51/2F/o/ZzaA5mZ nx5YMlhDOf3vHyzyO4KzYlG8md3RQU7eKQQDxgRfW1v0f7WVQoC2Dxbupyz0JVV4jQStYUYW ifGsh76wI3rkzlq3F2Ea/+jqMxX/AZOO30tBAgMBAAE= -----END RSA PUBLIC KEY-----

Answer 1

您可以使用 BouncyCastle 库来实现此目的。您的密钥在 PEM fromat 中。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);
}

然后用这个密钥加密:

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));

测试版本：bcpkix-jdk15on and bcprov-jdk15on。

从 PKCS1 密钥获取 RSA public 密钥

Getting RSA public key from PKCS1 key

java

encryption

rsa

pkcs#1