Read and write passwords to a Java keystore file

KeyUtils.java

package keystuff;


import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.security.KeyStore;

public class KeyUtils {
    public static FileInputStream getFileInputStreamFromArg(String filePath) throws FileNotFoundException {
        File file = new File(filePath);
        return new FileInputStream(file);
    }

    public static KeyStore loadKeyStoreFromFile(String pathToFile, String keystorePassword)
            throws Exception {
        KeyStore keyStore = KeyStore.getInstance("JCEKS");
        keyStore.load(getFileInputStreamFromArg(pathToFile), keystorePassword.toCharArray());
        return keyStore;
    }
}

ReadPasswordFromKeyStore.java

package keystuff;


import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import java.security.KeyStore;

import static keystuff.KeyUtils.loadKeyStoreFromFile;

public class ReadPasswordFromKeyStore {

    public static void main(String[] args) throws Exception {

        checkArgs(args);

        String pathToKeyStore = args[0];
        String keystorePassword = args[1];
        String passwordPassword = args[2];
        String passwordAlias = args[3];

        KeyStore keyStore = loadKeyStoreFromFile(pathToKeyStore, keystorePassword);

        System.out.println("read password " + readPasswordFromKeyStore(keyStore, passwordPassword, passwordAlias));
    }

    private static void checkArgs(String[] args) {
        if(args.length != 4) {
            throw new IllegalArgumentException("Usage: ReadPasswordFromKeyStore <full path to keystore> <keystore password> <password password> <key alias>");
        }
    }

    private static String readPasswordFromKeyStore(KeyStore keyStore, String passwordPassword, String passwordAlias) throws Exception {

        KeyStore.PasswordProtection keyStorePP = new KeyStore.PasswordProtection(passwordPassword.toCharArray());

        KeyStore.SecretKeyEntry ske =
                (KeyStore.SecretKeyEntry)keyStore.getEntry(passwordAlias, keyStorePP);

        SecretKeyFactory factory = SecretKeyFactory.getInstance("PBE");
        PBEKeySpec keySpec = (PBEKeySpec)factory.getKeySpec(
                ske.getSecretKey(),
                PBEKeySpec.class);

        return new String(keySpec.getPassword());
    }
}

WritePasswordToKeyStore.java

package keystuff;


import javax.crypto.SecretKey;
import javax.crypto.SecretKeyFactory;
import javax.crypto.spec.PBEKeySpec;
import java.io.File;
import java.io.FileOutputStream;
import java.security.KeyStore;
import static keystuff.KeyUtils.loadKeyStoreFromFile;

public class WritePasswordToKeyStore {

    private static void checkArgs(String[] args) {
        if(args.length != 5) {
            throw new IllegalArgumentException("Usage: WritePasswordToKeyStore <full path to keystore> <keystore password> <password password> <key alias> <password to store>");
        }
    }

    private static void writePasswordToKeyStore(String pathToKeyStore, String keyStorePassword, String passwordPassword, String alias, String password)
        throws Exception {

        KeyStore keyStore = loadKeyStoreFromFile(pathToKeyStore, keyStorePassword);
        KeyStore.PasswordProtection keyStorePP = new KeyStore.PasswordProtection(passwordPassword.toCharArray());

        SecretKeyFactory factory = SecretKeyFactory.getInstance("PBE");
        SecretKey generatedSecret =
                factory.generateSecret(new PBEKeySpec(
                        password.toCharArray(),
                        "oh we're salty allright".getBytes(),
                        13
                ));

        keyStore.setEntry(alias, new KeyStore.SecretKeyEntry(
                generatedSecret), keyStorePP);

        FileOutputStream outputStream = new FileOutputStream(new File(pathToKeyStore));
        keyStore.store(outputStream, keyStorePassword.toCharArray());
    }

    public static void main(String[] args) throws Exception{

        checkArgs(args);

        String pathToKeyStore = args[0];
        String keystorePassword = args[1];
        String passwordPassword = args[2];
        String passwordAlias = args[3];
        String passwordToStore = args[4];


        writePasswordToKeyStore(pathToKeyStore, keystorePassword, passwordPassword, passwordAlias, passwordToStore);

    }
}