cR

package ivb511.crypto;

import javax.crypto.*;
import java.io.*;
import java.security.*;
import java.security.cert.CertificateEncodingException;
import java.security.cert.CertificateException;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

public class JavaCrypto {
    private final static int EXIT = 11;
    private static KeyStore keyStore;
    private static KeyGenerator secretKeyGenerator;
    private static Cipher cipher;
    private static Cipher keyWrapper;
    private static Signature sig;
    private static BufferedReader br;

    static {
        try {
            br = new BufferedReader(new InputStreamReader(System.in));
            secretKeyGenerator = KeyGenerator.getInstance("RC4");
            secretKeyGenerator.init(new SecureRandom());
            keyWrapper = Cipher.getInstance("RSA");
            cipher = Cipher.getInstance("RC4");
            keyStore = KeyStore.getInstance("JCEKS");
            sig = Signature.getInstance("MD5withRSA");
        } catch (NoSuchAlgorithmException | KeyStoreException | NoSuchPaddingException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        int menuItem = 0;
        do try {
            switch (menuItem = getMenuItem()) {
                case 1:
                    createKeyStore();
                    break;
                case 2:
                    loadKeyStore();
                    break;
                case 3:
                    saveKeyStore();
                    break;
                case 4:
                    importCertificate();
                    break;
                case 5:
                    exportCertificate();
                    break;
                case 6:
                    createSymmetricKey();
                    break;
                case 7:
                    exportSymmetricKey();
                    break;
                case 8:
                    importSymmetricKey();
                    break;
                case 9:
                    encryptAndSignMessage();
                    break;
                case 10:
                    decryptCiphertexrAndVerifySignature();
                    break;
                case 11:
                    break;
                default:
                    System.out.println("Не верно выбрано действие");

            }

        } catch (Exception e) {
            e.printStackTrace();
        }
        while (menuItem != EXIT);
    }

    private static void createSymmetricKey() throws IOException, KeyStoreException {
        String keyAlias = getStr("\nType key alias, please");
        char[] password = getStr("Type password, please").toCharArray();
        SecretKey secretKey = secretKeyGenerator.generateKey();
        keyStore.setEntry(keyAlias, new KeyStore.SecretKeyEntry(secretKey), new KeyStore.PasswordProtection(password));
        System.out.println("\nThe symmetric key was successfully created. \n");
    }

    private static void decryptCiphertexrAndVerifySignature() throws IOException, SignatureException, InvalidKeyException, KeyStoreException, UnrecoverableKeyException, NoSuchAlgorithmException {
        String skAlias = getStr("Type symmetric key alias, please");
        char[] skPassword = getStr("Type symmetric key alias, please").toCharArray();
        String ciphertextFileName = getStr("Type name of file to read ciphertext from, please");
        String signatureFileName = getStr("Type signature file name, please");
        String certAlias = getStr("Type certificate alias to verify signature, please");
        SecretKey secretKey = (SecretKey) keyStore.getKey(skAlias, skPassword);
        cipher.init(Cipher.DECRYPT_MODE, secretKey);
        FileInputStream fis = new FileInputStream(ciphertextFileName);
        byte[] message = new byte[fis.available()];
        CipherInputStream cis = new CipherInputStream(fis, cipher);
        cis.read(message);
        System.out.println("The message is: " + new String(message) + ".");
        cis.close();

        fis = new FileInputStream(signatureFileName);
        byte[] ds = new byte[fis.available()];
        fis.read(ds);
        fis.close();

        X509Certificate cert = (X509Certificate) keyStore.getCertificate(certAlias);
        sig.initVerify(cert.getPublicKey());
        sig.update(message);
        System.out.println(sig.verify(ds) ? "The signature matches." : "The signature does not match.");

    }

    private static void encryptAndSignMessage() throws IOException, InvalidKeyException, SignatureException, UnrecoverableKeyException, NoSuchAlgorithmException, KeyStoreException {
        String keyAlias = getStr("\nType symmetric key alias, please");
        char[] skPassword = getStr("Type symmetric key password, please").toCharArray();
        String message = getStr("Type your message to be encrypted, please");
        String ciphertextFileName = getStr("Type name of file to save encrypted message to, please");
        String prvkAlias = getStr("Type private key alias to sign the message, please");
        char[] prvkPassword = getStr("Type private key password, please").toCharArray();
        String signatureFileName = getStr("Type name of file to save signature, please");
        SecretKey secretKey = (SecretKey) keyStore.getKey(keyAlias, skPassword);
        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
        CipherOutputStream cos = new CipherOutputStream(new FileOutputStream(ciphertextFileName), cipher);
        cos.write(message.getBytes());
        cos.flush();
        cos.close();
        PrivateKey privateKey = (PrivateKey) keyStore.getKey(prvkAlias, prvkPassword);
        sig.initSign(privateKey);
        sig.update(message.getBytes());
        byte[] ds = sig.sign();
        FileOutputStream fos = new FileOutputStream(signatureFileName);
        fos.write(ds);
        fos.flush();
        fos.close();
    }


    private static void importSymmetricKey() throws NoSuchAlgorithmException, InvalidKeyException, IOException, UnrecoverableKeyException, KeyStoreException {
        String skFileName = getStr("\nType file name to import from, please");
        String prvkAlias = getStr("Type private key alias, please");
        char[] prvkPassword = getStr("Type private key alias, please").toCharArray();
        String skAlias = getStr("Type alias to store symmetric key, please");
        char[] skPassword = getStr("Type symmetric key password, please").toCharArray();
        FileInputStream fis = new FileInputStream(skFileName);
        byte[] wrappedKey = new byte[fis.available()];
        fis.read();
        fis.close();
        keyWrapper.init(Cipher.UNWRAP_MODE, keyStore.getKey(prvkAlias, prvkPassword));
        SecretKey secretKey = (SecretKey) keyWrapper.unwrap(wrappedKey, "RC4", Cipher.SECRET_KEY);
        keyStore.setEntry(skAlias, new KeyStore.SecretKeyEntry(secretKey), new KeyStore.PasswordProtection(skPassword));
        System.out.println("\nThe symmetric key was successfully imported. \n");

    }


    private static void exportSymmetricKey() throws IOException, KeyStoreException, InvalidKeyException, IllegalBlockSizeException, UnrecoverableKeyException, NoSuchAlgorithmException {
        String skAlias = getStr("\nType symmetric key alias, please");
        char[] password = getStr("Type symmetric key password, please").toCharArray();
        String certAlias = getStr("Type certificate alias, please");
        String skFileName = getStr("Type name of a file to export the symmetric key, please");
        SecretKey key = (SecretKey) keyStore.getKey(skAlias, password);
        X509Certificate cert = (X509Certificate) keyStore.getCertificate(certAlias);
        keyWrapper.init(Cipher.WRAP_MODE, cert.getPublicKey());
        byte wrappedKey[] = keyWrapper.wrap(key);
        FileOutputStream fos = new FileOutputStream(skFileName);
        fos.write(wrappedKey);
        fos.flush();
        fos.close();
    }

    private static void exportCertificate() throws IOException, KeyStoreException, CertificateEncodingException {
        String alias = getStr("\nType certificate alias, please");
        String certFileName = getStr("Type certificate file name, please");
        X509Certificate cert = (X509Certificate) keyStore.getCertificate(alias);
        FileOutputStream fos = new FileOutputStream(certFileName);
        fos.write(cert.getEncoded());
        fos.close();
        System.out.println("\nThe certificate was successfully exported. \n");

    }

    private static void importCertificate() throws CertificateException, IOException, KeyStoreException {
        String fileName = getStr("\nType file name, please");
        String alias = getStr("\nType file name, please");
        FileInputStream fis = new FileInputStream(fileName);
        CertificateFactory cf = CertificateFactory.getInstance("X.509");
        X509Certificate cert = (X509Certificate) cf.generateCertificate(fis);
        fis.close();
        keyStore.setCertificateEntry(alias, cert);
        System.out.println("\nThe certificate was successfully imported. \n");
    }


    private static void saveKeyStore() throws IOException, CertificateException, NoSuchAlgorithmException, KeyStoreException {
        String fileName = getStr("\nType file name, please");
        char[] password = getStr("Type the keystore password,please").toCharArray();
        FileOutputStream fos = new FileOutputStream(fileName);
        keyStore.store(fos, password);
        fos.flush();
        fos.close();
        System.out.println("\nThe keystore was successfully saved. \n");
    }

    private static void loadKeyStore() throws IOException, CertificateException, NoSuchAlgorithmException {
        String fileName = getStr("\nType file name, please");
        char[] password = getStr("Type the keystore password, please").toCharArray();
        FileInputStream fis = new FileInputStream(fileName);
        keyStore.load(fis, password);
        fis.close();
        System.out.println("\nThe keystore was succesfully loaded. \n");
    }

    private static void createKeyStore() throws CertificateException, NoSuchAlgorithmException, IOException {
        char[] password = getStr("\nType the keystore password, please").toCharArray();
        keyStore.load(null, password);
        System.out.println("\nThe new keystore was successfully created. \n");
    }

    private static int getMenuItem() throws Exception {
        System.out.println("Menu");
        System.out.println("---------------------");
        System.out.println("1. Create keystore");
        System.out.println("2. Load keystore");
        System.out.println("3. Save keystore");
        System.out.println("4. Import certificate");
        System.out.println("5. Export certificate");
        System.out.println("6. Create symmetric key");
        System.out.println("7. Export symetric key");
        System.out.println("8. Import symmetric key");
        System.out.println("9. Encrypt and sign message");
        System.out.println("10. Decrypt ciphertext and verify signature");
        System.out.println("11. Exit");
        System.out.println("---------------------");
        return Integer.parseInt(getStr("Type menu item, please"));
    }

    private static String getStr(String s) throws IOException {
        System.out.println(s + ": ");
        return br.readLine();
    }
}