Java tutorial
/* * Copyright (c) 2008 - 2013 10gen, Inc. <http://10gen.com> * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ package com.andiandy.m101j.week2.hw3; import com.mongodb.BasicDBObject; import com.mongodb.DB; import com.mongodb.DBCollection; import com.mongodb.DBObject; import com.mongodb.MongoException; import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.security.SecureRandom; import java.util.Random; import org.apache.commons.codec.binary.Base64; public class UserDAO { private final DBCollection usersCollection; private Random random = new SecureRandom(); public UserDAO(final DB blogDatabase) { usersCollection = blogDatabase.getCollection("users"); } // validates that username is unique and insert into db public boolean addUser(String username, String password, String email) { String passwordHash = makePasswordHash(password, Integer.toString(random.nextInt())); // XXX WORK HERE // create an object suitable for insertion into the user collection // be sure to add username and hashed password to the document. problem instructions // will tell you the schema that the documents must follow. BasicDBObject user = new BasicDBObject("_id", username).append("password", passwordHash); if (email != null && !email.equals("")) { // XXX WORK HERE // if there is an email address specified, add it to the document too. user.append("email", email); } try { // XXX WORK HERE // insert the document into the user collection here usersCollection.insert(user); return true; } catch (MongoException.DuplicateKey e) { System.out.println("Username already in use: " + username); return false; } } public DBObject validateLogin(String username, String password) { DBObject user = null; // XXX look in the user collection for a user that has this username // assign the result to the user variable. user = usersCollection.findOne(new BasicDBObject("_id", username)); if (user == null) { System.out.println("User not in database"); return null; } String hashedAndSalted = user.get("password").toString(); String salt = hashedAndSalted.split(",")[1]; if (!hashedAndSalted.equals(makePasswordHash(password, salt))) { System.out.println("Submitted password is not a match"); return null; } return user; } private String makePasswordHash(String password, String salt) { try { String saltedAndHashed = password + "," + salt; MessageDigest digest = MessageDigest.getInstance("MD5"); digest.update(saltedAndHashed.getBytes()); byte hashedBytes[] = (new String(digest.digest(), "UTF-8")).getBytes(); return new String(Base64.encodeBase64(hashedBytes)) + "," + salt; } catch (NoSuchAlgorithmException e) { throw new RuntimeException("MD5 is not available", e); } catch (UnsupportedEncodingException e) { throw new RuntimeException("UTF-8 unavailable? Not a chance", e); } } }