import java.security.*;
import java.security.spec.*;
import javax.crypto.*;

public static HashMap genarateRSAKeyPair() throws NoSuchAlgorithmException {
    PublicKey publicKey = null;
    PrivateKey privateKey = null;

    SecureRandom secureRandom = new SecureRandom();
    KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("RSA");
    keyPairGenerator.initialize(512, secureRandom);

    KeyPair keyPair = keyPairGenerator.genKeyPair();
    publicKey = keyPair.getPublic();
    privateKey = keyPair.getPrivate();

    HashMap map = new HashMap();
    map.put("publickey", publicKey);
    map.put("privatekey", privateKey);
    return map;
}
public static byte[] rsaEncrypt(PublicKey publicKey, byte[] bPlain) throws NoSuchPaddingException, NoSuchAlgorithmException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
    Cipher cipher = Cipher.getInstance("RSA");

    // 공개키 이용 암호화
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    byte[] bCipher = cipher.doFinal(bPlain);
    return bCipher;
}
public static byte[] rsaDecrypt(PrivateKey privateKey, byte[] bEncyptedData) throws NoSuchPaddingException, NoSuchAlgorithmException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
    Cipher cipher = Cipher.getInstance("RSA");

    // 개인키 이용 복호화
    cipher.init(Cipher.DECRYPT_MODE, privateKey);
    byte[] bPlain = cipher.doFinal(bEncyptedData);
    return bPlain;
}
public static byte[] rsaSign(PrivateKey privateKey, byte[] bPlain) throws NoSuchPaddingException, NoSuchAlgorithmException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, SignatureException {
    Cipher cipher = Cipher.getInstance("RSA");

    // sign
    Signature rsa = Signature.getInstance("SHA256withRSA");
    rsa.initSign(privateKey);
    rsa.update(SHA256(bPlain));
    byte[] ds = rsa.sign();
    return ds;
}
public static boolean rsaSignVerify(PublicKey publicKey, byte[] bPlain, byte[] bSign) throws NoSuchPaddingException, NoSuchAlgorithmException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, SignatureException {
    Cipher cipher = Cipher.getInstance("RSA");

    Signature rsa = Signature.getInstance("SHA256withRSA");
    rsa.initVerify(publicKey);
    rsa.update(SHA256(bPlain));
    boolean rtnVal = rsa.verify(bSign);
    return rtnVal;
}

HashMap key = UtilClass.genarateRSAKeyPair();
String plain = "000001" + System.lineSeparator() +
        "192.168.0.8" + System.lineSeparator() +
        "90-78-41-57-56-2F" + System.lineSeparator() +
        "5" + System.lineSeparator() +
        "20231231" + System.lineSeparator();
byte[] baSign = UtilClass.rsaSign((PrivateKey) key.get("privatekey"), plain.getBytes());
String license = plain +  UtilClass.Base64Encode(baSign);

String ip =UtilClass.getAddress1();
String mac = UtilClass.getMacAddress1();

String[] data = license.split(System.lineSeparator());


boolean bResult = UtilClass.rsaSignVerify((PublicKey) key.get("publickey"), plain.getBytes(), UtilClass.Base64Decode(data[5]));

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