Problem with storing key into database and decrypting the password.....

Question

Hi every one, i have prob with this code
import java.security.NoSuchAlgorithmException;
import java.sql.Blob;
import java.sql.ResultSet;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import java.security.Key;
import java.io.*;
import java.security.InvalidKeyException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
public class SecurityUtil {
public static final String ALGORITHM ="DES";
public static Cipher cipher;
SecurityUtil() throws NoSuchAlgorithmException, NoSuchPaddingException {
cipher = Cipher.getInstance(ALGORITHM);}
public static void serializeKey(Key key, File file) {
//serializing
try {     FileOutputStream fos = new FileOutputStream(file);
ObjectOutputStream oos = new ObjectOutputStream(fos);
oos.writeObject(key);
oos.flush();
oos.close(); } catch (Exception e) { System.out.println("Exception during serialization: " + e);
System.exit(0); } }
public static SecretKey deserializeKey(File file) {   //deserializing
SecretKey key1 = null;
try {  FileInputStream fis = new FileInputStream(file);
ObjectInputStream ois = new ObjectInputStream(fis);
key1 = (SecretKey) ois.readObject();
ois.close();
System.out.println("object2: " + key1); } catch (Exception e) {
System.out.println("Exception during deserialization: " + e);
System.exit(0);}
return key1;
public static byte[] encrypt(String input, SecretKey key) throws InvalidKeyException, BadPaddingException,
IllegalBlockSizeException {
cipher.init(Cipher.ENCRYPT_MODE, key);
byte[] inputBytes = input.getBytes();
return cipher.doFinal(inputBytes);
public static String decrypt(byte[] encryptionBytes, SecretKey key) throws InvalidKeyException,
BadPaddingException, IllegalBlockSizeException {
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] recoveredBytes = cipher.doFinal(encryptionBytes);
String recovered = new String(recoveredBytes);
return recovered;
public static void main(String[] args) throws Exception {
SecurityUtil su = new SecurityUtil();
// SecurityUtil.testUsingSerialization();
SecurityUtil.testWithDatabase();
public static void testUsingSerialization() throws Exception {
KeyGenerator kg = KeyGenerator.getInstance("DES");
kg.init(56); // 56 is the keysize. Fixed for DES
SecretKey key = kg.generateKey();
File file1 = new File("root:/testKey.key");
serializeKey(key, file1);
SecretKey deserializedKey = deserializeKey(file1);
byte[] encryptionBytes = encrypt("input", key);
System.out.println("Recovered: " + decrypt(encryptionBytes, deserializedKey));
public static void testWithDatabase() throws Exception {
KeyGenerator kg = KeyGenerator.getInstance("DES");
kg.init(56); // 56 is the keysize. Fixed for DES
SecretKey key = kg.generateKey();
boolean insertResult = insert("prasunay","prasunay",key);
System.out.println("<<======= insert result: " + insertResult);
boolean validateAuthenticationDetails = validateAuthenticationDetails("prasunay","prasunay");
System.out.println("<<======= right values:" + validateAuthenticationDetails);
boolean validateAuthenticationDetails1 = validateAuthenticationDetails("prasunay","prasun");
System.out.println("<<======= WRONG values:" + validateAuthenticationDetails1);
System.out.print("done!"); }
public static boolean insert(String username,String password,SecretKey key) throws Exception {
// mysql> CREATE TABLE myusers (user_name VARCHAR(20), pass_word VARCHAR(20), my_key BLOB);
// Query OK, 0 rows affected (0.03 sec)
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/users?user=root&password=");
PreparedStatement ps = con.prepareStatement("INSERT INTO myusers VALUES (?, ?, ?)");
ps.setString(1,username);
byte[] encryptionBytes = encrypt(password, key);
ps.setString(2, new String(encryptionBytes));
ByteArrayInputStream ois = getStreamFromKey(key);
byte[] keyBytes = getBytesFromKey(key);
System.out.println("Key Length" + keyBytes.length);
ps.setBinaryStream(3, ois, keyBytes.length);
int result = ps.executeUpdate();
System.out.println(result);
ps.close();
con.close();
if (result > 0) {
return true;
} else {
return false; } }

Answer 1

code continuation.......
public static boolean validateAuthenticationDetails(String username, String password) throws Exception {
boolean result = false;
// mysql> CREATE TABLE myusers (user_name VARCHAR(20), pass_word VARCHAR(20), my_key BLOB);
// Query OK, 0 rows affected (0.03 sec)
Class.forName("com.mysql.jdbc.Driver");
Connection con = DriverManager.getConnection("jdbc:mysql://localhost/users?user=root&password=");
PreparedStatement ps = con.prepareStatement("select my_key,pass_word from myusers where user_name = ?");
ps.setString(1, username);
ResultSet resultSet = ps.executeQuery();
if (resultSet.next()) {
String passwordFromDB = resultSet.getString("pass_word");
Blob keyBlob = resultSet.getBlob("my_key");
System.out.println(keyBlob);
System.out.println("key" + resultSet.getBinaryStream("my_key").read());
InputStream keyInputBinaryStream = keyBlob.getBinaryStream();
System.out.println("keyInputBinaryStream: " + keyInputBinaryStream);
System.out.println("keyInputBinaryStream: " + keyInputBinaryStream.available());
ObjectInputStream ois = new ObjectInputStream(keyInputBinaryStream);
SecretKey key = (SecretKey) ois.readObject();
System.out.println(key);
String decryptedPwd = decrypt(passwordFromDB.getBytes(), key);
System.out.println("Decrypted pwd : " + decryptedPwd);
System.out.println("pwd sent for authorization : " + password);
if (password.equals(decryptedPwd)) {
result = true;
} else {result = false;   }
} else {
System.out.println("Invalid user!!"); }
ps.close();
con.close();
return result; }
public static ByteArrayInputStream getStreamFromKey(SecretKey key) throws Exception {
ByteArrayOutputStream o = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(o);
out.writeObject(key);
byte[] keyBytes = o.toByteArray();
ByteArrayInputStream bis = new ByteArrayInputStream(keyBytes);
return bis;}
public static byte[] getBytesFromKey(SecretKey key) throws Exception {
ByteArrayOutputStream o = new ByteArrayOutputStream();
ObjectOutputStream out = new ObjectOutputStream(o);
out.writeObject(key);
byte[] keyBytes = o.toByteArray();
return keyBytes; } }
but it is giving following run-time error: Key Length263
1
<<======= insert result: true
com.mysql.jdbc.Blob@1ea0252
key172
keyInputBinaryStream: java.io.ByteArrayInputStream@3e89c3
keyInputBinaryStream: 263
javax.crypto.spec.SecretKeySpec@fffe7a51
Exception in thread "main" javax.crypto.IllegalBlockSizeException: Input length must be multiple of 8 when decrypting with padded cipher
plzz suggest some solution...