JDBC et Cryptographie

Le but de cette exercice est de stocké des donnée dans une base de donnée. Pour cela, on va faire une mini interface permettant de stocker des persoones dans une base SQLLite

<!-- https://mvnrepository.com/artifact/org.xerial/sqlite-jdbc -->
<dependency>
    <groupId>org.xerial</groupId>
    <artifactId>sqlite-jdbc</artifactId>
    <version>3.28.0</version>
</dependency>

 

Le code suivant permet de créer une base de donnée d'ajouter des personnes et de les lire:

 
public class JDBC
{
  public static void main(String[] args) throws ClassNotFoundException
  {
    // load the sqlite-JDBC driver using the current class loader
    Class.forName("org.sqlite.JDBC");
 
    Connection connection = null;
    try
    {
      // create a database connection
      connection = DriverManager.getConnection("jdbc:sqlite:sample.db");
      Statement statement = connection.createStatement();
      statement.setQueryTimeout(30);  // set timeout to 30 sec.
 
      statement.executeUpdate("drop table if exists person");
      statement.executeUpdate("create table person (id integer, name string)");
      statement.executeUpdate("insert into person values(1, 'leo')");
      statement.executeUpdate("insert into person values(2, 'yui')");
      ResultSet rs = statement.executeQuery("select * from person");
      while(rs.next())
      {
        // read the result set
        System.out.println("name = " + rs.getString("name"));
        System.out.println("id = " + rs.getInt("id"));
      }
    }
    catch(SQLException e)
    {
      // if the error message is "out of memory", 
      // it probably means no database file is found
      System.err.println(e.getMessage());
    }
    finally
    {
      try
      {
        if(connection != null)
          connection.close();
      }
      catch(SQLException e)
      {
        // connection close failed.
        System.err.println(e);
      }
    }
  }
}

 

Le code suivant permet de faire un peu de cryptographie:

	import java.io.UnsupportedEncodingException;
	import java.security.MessageDigest;
	import java.security.NoSuchAlgorithmException;
	import java.util.Arrays;
	import java.util.Base64;
	 
	import javax.crypto.Cipher;
	import javax.crypto.spec.SecretKeySpec;
	 
	public class AES {
	 
	    private static SecretKeySpec secretKey;
	    private static byte[] key;
	 
	    public static void setKey(String myKey) 
	    {
	        MessageDigest sha = null;
	        try {
	            key = myKey.getBytes("UTF-8");
	            sha = MessageDigest.getInstance("SHA-1");
	            key = sha.digest(key);
	            key = Arrays.copyOf(key, 16); 
	            secretKey = new SecretKeySpec(key, "AES");
	        } 
	        catch (NoSuchAlgorithmException e) {
	            e.printStackTrace();
	        } 
	        catch (UnsupportedEncodingException e) {
	            e.printStackTrace();
	        }
	    }
	 
	    public static String encrypt(String strToEncrypt, String secret) 
	    {
	        try
	        {
	            setKey(secret);
	            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
	            cipher.init(Cipher.ENCRYPT_MODE, secretKey);
	            return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes("UTF-8")));
	        } 
	        catch (Exception e) 
	        {
	            System.out.println("Error while encrypting: " + e.toString());
	        }
	        return null;
	    }
	 
	    public static String decrypt(String strToDecrypt, String secret) 
	    {
	        try
	        {
	            setKey(secret);
	            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
	            cipher.init(Cipher.DECRYPT_MODE, secretKey);
	            return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)));
	        } 
	        catch (Exception e) 
	        {
	            System.out.println("Error while decrypting: " + e.toString());
	        }
	        return null;
	    }
	    public static void main(String[] args) 
	    {
	        final String secretKey = "Pilou";
	         
	        String originalString = "Hello World";
	        String encryptedString = AES.encrypt(originalString, secretKey) ;
	        String decryptedString = AES.decrypt(encryptedString, secretKey) ;
	         
	        System.out.println(originalString);
	        System.out.println(encryptedString);
	        System.out.println(decryptedString);
	    }
}

 

L'idée est d'utiliser lanterna afin de faire un petit formulaire qui sauvegarderas en base des personnes de facon crypté.