MainClass.java Source code

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Here is the source code for MainClass.java

Source

import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.Security;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;

import javax.crypto.Cipher;

public class MainClass {
    public static void main(String[] args) throws Exception {
        Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

        byte[] input = new byte[] { (byte) 0xbe, (byte) 0xef };
        Cipher cipher = Cipher.getInstance("RSA/None/NoPadding", "BC");

        KeyFactory keyFactory = KeyFactory.getInstance("RSA", "BC");
        RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger("12345678", 16),
                new BigInteger("11", 16));
        RSAPrivateKeySpec privKeySpec = new RSAPrivateKeySpec(new BigInteger("12345678", 16),
                new BigInteger("12345678", 16));

        RSAPublicKey pubKey = (RSAPublicKey) keyFactory.generatePublic(pubKeySpec);
        RSAPrivateKey privKey = (RSAPrivateKey) keyFactory.generatePrivate(privKeySpec);

        cipher.init(Cipher.ENCRYPT_MODE, pubKey);

        byte[] cipherText = cipher.doFinal(input);
        System.out.println("cipher: " + new String(cipherText));

        cipher.init(Cipher.DECRYPT_MODE, privKey);
        byte[] plainText = cipher.doFinal(cipherText);
        System.out.println("plain : " + new String(plainText));
    }
}