import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Random;

public class PasswordSaltedHashExample {
	public static void main(String[] args) {
		String password = "MyPass123";
		String SaltString = getSaltString(32);
		System.out.println("SaltString: " + SaltString);

		String passwordToHash = password + SaltString;
		String generatedPassword = null;
		try {
			// Create MessageDigest instance for MD5
			MessageDigest md = MessageDigest.getInstance("SHA-256");
			// Add password bytes to digest
			md.update(passwordToHash.getBytes());
			// Get the hash's bytes
			byte[] bytes = md.digest();
			// This bytes[] has bytes in decimal format;
			// Convert it to hexadecimal format
			StringBuilder sb = new StringBuilder();
			for (int i = 0; i < bytes.length; i++) {
				sb.append(Integer.toString((bytes[i] & 0xff) + 0x100, 16).substring(1));
			}
			// Get complete hashed password in hex format
			generatedPassword = sb.toString();
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		}
		System.out.println("PasswordSaltedHash: " + generatedPassword);

	}

	public static String getSaltString(int length) {

		final char[] allAllowed = "abcdefghijklmnopqrstuvwxyzABCDEFGJKLMNPRSTUVWXYZ0123456789".toCharArray();

		Random random = new SecureRandom();

		StringBuilder salt = new StringBuilder();

		for (int i = 0; i < length; i++) {
			salt.append(allAllowed[random.nextInt(allAllowed.length)]);
		}

		return salt.toString();

	}
}