Added hashing and salt generation

src/main/java/dao/UserDAO.java

@@ -3,6 +3,7 @@ package dao;
 import data.User;
 
 import java.nio.charset.StandardCharsets;
+import java.security.DigestException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
 import java.security.SecureRandom;
@@ -184,7 +185,8 @@ public class UserDAO {
      * @return a random salt
      */
     public byte[] generateSalt() {
-        return null;
+        SecureRandom random = new SecureRandom();
+        return random.generateSeed(16);
     }
 
     /**
@@ -194,8 +196,20 @@ public class UserDAO {
      * @return hashedPassword, null if unsuccessful
      */
     public String hashPassword(String password, byte[] salt) {
+        try {
+            MessageDigest md = java.security.MessageDigest.getInstance("SHA-256");
+            md.update(salt);
+            byte[] digest = (md.digest(password.getBytes()));
+            StringBuilder stringBuilder = new StringBuilder();
+            for(int i = 0; i < digest.length; i++){
+                stringBuilder.append(Integer.toString((digest[i] & 0xff) + 0x100,
+                    16).substring(1));
+            }
+            return stringBuilder.toString();
+        } catch (Exception e) {
             return null;
         }
+    }
 
     /**
      * Edits the users username or password