Created
January 27, 2018 16:19
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| const crypto = require("crypto"); | |
| class Db { | |
| constructor(users={}) { | |
| this.users = users; | |
| } | |
| // Expects passwordPayload to be a string of the form 'salt$passwordHash' | |
| // Where the '$' is used as a separator. | |
| storeUser(username, passwordPayload) { | |
| this.users[username] = passwordPayload; | |
| } | |
| getUserPassword(username) { | |
| let hash = this.users[username]; | |
| return { | |
| salt: hash.substr(0, hash.indexOf('$')), | |
| passwordHash: hash.substr(hash.indexOf('$') + 1) | |
| }; | |
| } | |
| } | |
| const db = new Db(); | |
| // STUDENT CODE STARTS HERE ------------ | |
| const hashPassword = (password, salt) => { | |
| const passwordHash = crypto.pbkdf2Sync(password, salt, 70451, 64, 'sha256'); | |
| return passwordHash.toString('hex'); | |
| }; | |
| const saveUser = (username, password) => { | |
| const salt = crypto.randomBytes(64).toString('hex'); | |
| const passwordHash = hashPassword(password, salt); | |
| const payload = `${salt}$${passwordHash}`; | |
| db.storeUser(username, payload); | |
| }; | |
| // Return true if authenticated, false otherwise. | |
| const isUserAuthenticated = (username, password) => { | |
| let payload; | |
| try { | |
| payload = db.getUserPassword(username); | |
| } catch (error) { | |
| if (!(error instanceof TypeError)) throw error; | |
| // insert work | |
| hashPassword('notARealPassword', 'mySaltIsbetterThanMyPepper'); | |
| return false; | |
| } | |
| const { salt, passwordHash } = payload; | |
| return comparePasswords(password, salt, passwordHash); | |
| }; | |
| // returns true if passwords match, otherwise false. | |
| const comparePasswords = (plaintextPassword, salt, passwordHashFromDb) => { | |
| return hashPassword(plaintextPassword, salt) === passwordHashFromDb; | |
| }; | |
| // STUDENT CODE ENDS HERE ------------ | |
| saveUser('jane@email.com', '123456qwerty'); | |
| console.time('1') | |
| console.log(isUserAuthenticated('jane@email.com', 'HelloWorld!')) // false | |
| console.timeEnd('1') | |
| console.time('2') | |
| console.log(isUserAuthenticated('jane@email.com', 'HelloWorld!')) // false | |
| console.timeEnd('2') | |
| console.time('3') | |
| console.log(isUserAuthenticated('iAmNotInTheDb@email.com', 'HelloWorld!')) // false | |
| console.timeEnd('3') | |
| console.time('4') | |
| console.log(isUserAuthenticated('jane@email.com', '123456qwerty')) // true | |
| console.timeEnd('4') | |
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