# Authentication using Fluent Fluent builds on Vapor's [Authentication](../authentication.md) API to provide an easy, customizable way to do user authentication using database models. ## Introduction Fluent defines two protocols `ModelUser` and `ModelUserToken` which can be added to your existing models. Conforming your models to these protocols allows for the creation of authenticators which generate middleware for protecting endpoints. `ModelUserToken` authenticates with a Bearer token. This is what you use to protect most of your endpoints. `ModelUser` authenticates with username and password and is used by a single endpoint for generating tokens. This guide assumes you are familiar with Fluent and have successfully configured your app to use a database. If you are new to Fluent, start with the [overview](overview.md). ## User To start, you will need a model representing the user that will be authenticated. For this guide, we'll be using the following model, but you are free to use an existing model. ```swift import Fluent import Vapor final class User: Model, Content { static let schema = "users" @ID(key: .id) var id: UUID? @Field(key: "name") var name: String @Field(key: "email") var email: String @Field(key: "password_hash") var passwordHash: String init() { } init(id: UUID? = nil, name: String, email: String, passwordHash: String) { self.id = id self.name = name self.email = email self.passwordHash = passwordHash } } ``` The model must be able to store a username, in this case an email, and a password hash. The corresponding migration for this example model is here: ```swift import Fluent import Vapor extension User { struct Migration: Fluent.Migration { var name: String { "CreateUser" } func prepare(on database: Database) -> EventLoopFuture { database.schema("users") .id() .field("name", .string, .required) .field("email", .string, .required) .field("password_hash", .string, .required) .create() } func revert(on database: Database) -> EventLoopFuture { database.schema("users").delete() } } } ``` Don't forget to add the migration to `app.migrations`. ```swift app.migrations.add(User.Migration()) ``` The first thing you will need is an endpoint to create new users. Let's use `POST /users`. Create a [Content](../content.md) struct representing the data this endpoint expects. ```swift import Vapor extension User { struct Create: Content { var name: String var email: String var password: String var confirmPassword: String } } ``` If you like, you can conform this struct to [Validatable](../validation.md) to add validation requirements. ```swift import Vapor extension User.Create: Validatable { static func validations(_ validations: inout Validations) { validations.add("name", as: String.self, is: !.empty) validations.add("email", as: String.self, is: .email) validations.add("password", as: String.self, is: .count(8...)) } } ``` Now you can create the `POST /users` endpoint. ```swift app.post("users") { req -> EventLoopFuture in try User.Create.validate(req) let create = try req.content.decode(User.Create.self) guard create.password == create.confirmPassword else { throw Abort(.badRequest, reason: "Passwords did not match") } let user = try User( name: create.name, email: create.email, passwordHash: Bcrypt.hash(create.password) ) return user.save(on: req.db) .map { user } } ``` This endpoint validates the incoming request, decodes the `User.Create` struct, and checks that the passwords match. It then uses the decoded data to create a new `User` and saves it to the database. The plaintext password is hashed using `Bcrypt` before saving to the database. Build and run the project, making sure to migrate the database first, then use the following request to create a new user. ```http POST /users HTTP/1.1 Content-Length: 97 Content-Type: application/json { "name": "Vapor", "email": "test@vapor.codes", "password": "secret", "confirmPassword": "secret" } ``` ### Authenticator Now that you have a user model and an endpoint to create new users, let's conform the model to `ModelUser`. This will allow for the model to be authenticated using username and password. ```swift import Fluent import Vapor extension User: ModelUser { static let usernameKey = \User.$email static let passwordHashKey = \User.$passwordHash func verify(password: String) throws -> Bool { try Bcrypt.verify(password, created: self.passwordHash) } } ``` This extension adds `ModelUser` conformance to `User`. The first two properties specify which fields should be used for storing the username and password hash respectively. The `\` notation creates a key path to the fields that Fluent can use to access them. The last requirement is a method for verifying plaintext passwords sent in the Basic authentication header. Since we're using Bcrypt to hash the password during signup, we'll use Bcrypt to verify that the supplied password matches the stored password hash. Now that the `User` conforms to `ModelUser`, we can create a middleware from the authenticator to protect the login route. ```swift let passwordProtected = app.grouped(User.authenticator().middleware()) passwordProtected.post("login") { req -> User in try req.auth.require(User.self) } ``` `ModelUser` adds a static method `authenticator` for creating an [authenticator](../authentication.md). You can then use `middleware` to generate a middleware from the authenticator. Test that this route works by sending the following request. ```http POST /login HTTP/1.1 Authorization: Basic dGVzdEB2YXBvci5jb2RlczpzZWNyZXQ= ``` This request passes the username `test@vapor.codes` and password `secret` via the Basic authentication header. You should see the previously created user returned. While you could theoretically use Basic authentication to protect all of your endpoints, it's recommended to use a separate token instead. This minimizes how often you must send the user's sensitive password over the Internet. It also makes authentication much faster since you only need to perform password hashing during login. ## User Token Create a new model for representing user tokens. ```swift import Fluent import Vapor final class UserToken: Model, Content { static let schema = "user_tokens" @ID(key: .id) var id: UUID? @Field(key: "value") var value: String @Parent(key: "user_id") var user: User init() { } init(id: UUID? = nil, value: String, userID: User.IDValue) { self.id = id self.value = value self.$user.id = userID } } ``` This model must have a `value` field for storing the token's unique string. It must also have a [parent-relation](overview.md#parent) to the user model. You may add additional properties to this token as you see fit, such as an expiration date. Next, create a migration for this model. ```swift import Fluent extension UserToken { struct Migration: Fluent.Migration { var name: String { "CreateUserToken" } func prepare(on database: Database) -> EventLoopFuture { database.schema("user_tokens") .id() .field("value", .string, .required) .field("user_id", .uuid, .required, .references("users", "id")) .unique(on: "value") .create() } func revert(on database: Database) -> EventLoopFuture { database.schema("user_tokens").delete() } } } ``` Notice that this migration makes the `value` field unique. It also creates a foreign key reference between the `user_id` field and the users table. Don't forget to add the migration to `app.migrations`. ```swift app.migrations.add(UserToken.Migration()) ``` Finally, add a method on `User` for generating a new token. This method will be used during login. ```swift extension User { func generateToken() throws -> UserToken { try .init( value: [UInt8].random(count: 16).base64, userID: self.requireID() ) } } ``` Here we're using `[UInt8].random(count:)` to generate a random token value. For this example, 16 bytes, or 128 bits, of random data are being used. You can adjust this number as you see fit. The random data is then base-64 encoded to make it easy to transmit in HTTP headers. Now that you can generate user tokens, update the `POST /login` route to create and return a token. ```swift let passwordProtected = app.grouped(User.authenticator().middleware()) passwordProtected.post("login") { req -> EventLoopFuture in let user = try req.auth.require(User.self) let token = try user.generateToken() return token.save(on: req.db) .map { token } } ``` Test that this route works by using the same login request from above. You should now get a token upon logging in that looks something like: ``` 8gtg300Jwdhc/Ffw784EXA== ``` Hold onto the token you get as we'll use it shortly. ### Authenticator Conform `UserToken` to `ModelUserToken`. This will allow for tokens to authenticate your `User` model. ```swift import Vapor import Fluent extension UserToken: ModelUserToken { static let valueKey = \UserToken.$value static let userKey = \UserToken.$user var isValid: Bool { true } } ``` The first protocol requirement specifies which field stores the token's unique value. This is the value that will be sent in the Bearer authentication header. The second requirement specifies the parent-relation to the `User` model. This is how Fluent will look up the authenticated user. The final requirement is an `isValid` boolean. If this is `false`, the token will be deleted from the database and the user will not be authenticated. For simplicity, we'll make the tokens eternal by hard-coding this to `true`. Now that the token conforms to `ModelUserToken`, you can create an authenticator and middleware for protecting routes. Create a new endpoint `GET /me` for getting the currently authenticated user. ```swift let tokenProtected = app.grouped(UserToken.authenticator().middleware()) tokenProtected.get("me") { req -> User in try req.auth.require(User.self) } ``` Similar to `User`, `UserToken` now has a static `authenticator()` method that can generate a middleware with `middleware()`. The middleware will attempt to find a matching `UserToken` using the value provided in the Bearer authentication header. If it finds a match, it will fetch the related `User` and authenticate it. Test that this route works by sending the following HTTP request where the token is the value you saved from the `POST /login` request. ```http GET /me HTTP/1.1 Authorization: Bearer ``` You should see the authenticated `User` returned.