NestJS - Implementing Access & Refresh Token Authentication

authentication-1.controller.ts

// app/modules/authentication/authentication.controller.ts

import { Body, Controller, Post } from '@nestjs/common'

import { RegisterRequest } from './requests'

import { User } from '../../modules/user'

import { UsersService } from '../users/users.service'

export interface AuthenticationPayload {
  user: User
  payload: {
    type: string
    token: string
    refresh_token?: string
  }
}

@Controller('/api/auth')
export class AuthenticationController {
  private readonly users: UsersService
  private readonly tokens: TokensService

  public constructor (users: UsersService, tokens: TokensService) {
    this.users = users
    this.tokens = tokens
  }

  @Post('/register')
  public async register (@Body() body: RegisterRequest) {
    const user = await this.users.createUserFromRequest(body)

    const token = await this.tokens.generateAccessToken(user)
    const refresh = await this.tokens.generateRefreshToken(user, 60 * 60 * 24 * 30)

    const payload = this.buildResponsePayload(user, token, refresh)

    return {
      status: 'success',
      data: payload,
    }
  }

  private buildResponsePayload (user: User, accessToken: string, refreshToken?: string): AuthenticationPayload {
    return {
      user: user,
      payload: {
        type: 'bearer',
        token: accessToken,
        ...(refreshToken ? { refresh_token: refreshToken } : {}),
      }
    }
  }
}

authentication-2.controller.ts

// app/modules/authentication/authentication.controller.ts

import { Body, Controller, Post, UnauthorizedException } from '@nestjs/common'

import { RegisterRequest, LoginRequest } from '../requests'

import { User } from '../../models/user.model'

import { UsersService } from '../users/users.service'

export interface AuthenticationPayload {
  user: User
  payload: {
    type: string
    token: string
    refresh_token?: string
  }
}

@Controller('/api/auth')
export class AuthenticationController {
  private readonly users: UsersService
  private readonly tokens: TokensService

  public constructor (users: UsersService, tokens: TokensService) {
    this.users = users
    this.tokens = tokens
  }

  @Post('/register')
  public async register (@Body() body: RegisterRequest) {
    const user = await this.users.createUserFromRequest(body)

    const token = await this.tokens.generateAccessToken(user)
    const refresh = await this.tokens.generateRefreshToken(user, 60 * 60 * 24 * 30)

    const payload = this.buildResponsePayload(user, token, refresh)

    return {
      status: 'success',
      data: payload,
    }
  }

  @Post('/login')
  public async login (@Body() body: LoginRequest) {
    const { username, password } = body

    const user = await this.users.findForUsername(username)
    const valid = user ? await this.users.validateCredentials(user, password) : false

    if (!valid) {
      throw new UnauthorizedException('The login is invalid')
    }

    const token = await this.tokens.generateAccessToken(user)
    const refresh = await this.tokens.generateRefreshToken(user, 60 * 60 * 24 * 30)

    const payload = this.buildResponsePayload(user, token, refresh)

    return {
      status: 'success',
      data: payload,
    }
  }

  private buildResponsePayload (user: User, accessToken: string, refreshToken?: string): AuthenticationPayload {
    return {
      user: user,
      payload: {
        type: 'bearer',
        token: accessToken,
        ...(refreshToken ? { refresh_token: refreshToken } : {}),
      }
    }
  }
}

authentication-3.controller.ts

// app/modules/authentication/authentication.controller.ts

import { Body, Controller, Post, UnauthorizedException } from '@nestjs/common'

import { RegisterRequest, LoginRequest, RefreshRequest } from '../requests'

import { User } from '../../models/user.model'

import { UsersService } from '../users/users.service'

export interface AuthenticationPayload {
  user: User
  payload: {
    type: string
    token: string
    refresh_token?: string
  }
}

@Controller('/api/auth')
export class AuthenticationController {
  private readonly users: UsersService
  private readonly tokens: TokensService

  public constructor (users: UsersService, tokens: TokensService) {
    this.users = users
    this.tokens = tokens
  }

  @Post('/register')
  public async register (@Body() body: RegisterRequest) {
    const user = await this.users.createUserFromRequest(body)

    const token = await this.tokens.generateAccessToken(user)
    const refresh = await this.tokens.generateRefreshToken(user, 60 * 60 * 24 * 30)

    const payload = this.buildResponsePayload(user, token, refresh)

    return {
      status: 'success',
      data: payload,
    }
  }

  @Post('/login')
  public async login (@Body() body: LoginRequest) {
    const { username, password } = body

    const user = await this.users.findForUsername(username)
    const valid = user ? await this.users.validateCredentials(user, password) : false

    if (!valid) {
      throw new UnauthorizedException('The login is invalid')
    }

    const token = await this.tokens.generateAccessToken(user)
    const refresh = await this.tokens.generateRefreshToken(user, 60 * 60 * 24 * 30)

    const payload = this.buildResponsePayload(user, token, refresh)

    return {
      status: 'success',
      data: payload,
    }
  }

  @Post('/refresh')
  public async refresh (@Body() body: RefreshRequest) {
    const { user, token } = await this.tokens.createAccessTokenFromRefreshToken(body.refresh_token)

    const payload = this.buildResponsePayload(user, token)

    return {
      status: 'success',
      data: payload,
    }
  }

  private buildResponsePayload (user: User, accessToken: string, refreshToken?: string): AuthenticationPayload {
    return {
      user: user,
      payload: {
        type: 'bearer',
        token: accessToken,
        ...(refreshToken ? { refresh_token: refreshToken } : {}),
      }
    }
  }
}

authentication-4.controller.ts

// app/modules/authentication/authentication.controller.ts
// ...

import { Controller, UseGuards, Get, Req } from '@nestjs/common'

import { JWTGuard } from './jwt.guard.ts'

// ...

@Controller('/api/auth')
export class AuthenticationController {
  // ...

  @Get('/me')
  @UseGuards(JWTGuard)
  public async getUser (@Req() request) {
    const userId = request.user.id

    const user = await this.users.findForId(userId)

    return {
      status: 'success',
      data: user,
    }
  }

  // ...
}

authentication.module.ts

// app/modules/authentication/authentication.module.ts

import { Module } from '@nestjs/common'
import { JwtModule } from '@nestjs/jwt'
import { SequelizeModule } from '@nestjs/sequelize'

import { UsersModule } from '../users/users.module'

import { RefreshToken } from '../../models/RefreshToken'

import { TokensService } from './tokens.service'
import { RefreshTokensRepository } from './refresh-tokens.repository'

import { AuthenticationController } from './authentication.controller'

@Module({
  imports: [
    SequelizeModule.forFeature([
      RefreshToken,
    ]),
    JwtModule.register({
      secret: '<SECRET KEY>',
      signOptions: {
        expiresIn: '5m',
      }
    }),
    UsersModule,
  ],
  controllers: [
    AuthenticationController,
  ],
  providers: [
    TokensService,
    RefreshTokensRepository,
  ],
})
export class AuthenticationModule {}

jwt.guard.ts

// app/modules/authentication/jwt.guard.ts

import { Injectable, UnauthorizedException } from '@nestjs/common'
import { AuthGuard } from '@nestjs/passport'

@Injectable()
export class JWTGuard extends AuthGuard('jwt') {

  handleRequest (err, user, info: Error) {
    if (err || info || !user) {
      throw err || info || new UnauthorizedException()
    }

    return user
  }

}

jwt.strategy.ts

// app/modules/authentication/jwt.strategy.ts

import { Injectable } from '@nestjs/common'
import { PassportStrategy } from '@nestjs/passport'
import { ExtractJwt, Strategy } from 'passport-jwt'

import { UsersService } from '../../users/users.service'

import { User } from '../../models'

export interface AccessTokenPayload {
  sub: number;
}

@Injectable()
export class JwtStrategy extends PassportStrategy(Strategy) {
  private users: UsersService

  public constructor (users: UsersService) {
    super({
      jwtFromRequest: ExtractJwt.fromAuthHeaderAsBearerToken(),
      ignoreExpiration: false,
      secretOrKey: '<SECRET KEY>',
      signOptions: {
        expiresIn: '5m',
      },
    })

    this.users = users
  }

  async validate (payload: AccessTokenPayload): Promise<User> {
    const { sub: id } = payload

    const user = await this.users.findForId(id)

    if (!user) {
      return null
    }

    return user
  }
}

refresh-token.model.ts

// app/models/refresh-token.model.ts

import { Table, Column, Model } from 'sequelize-typescript'

@Table({ tableName: 'refresh_tokens', underscored: true })
export class RefreshToken extends Model<RefreshToken> {
  @Column
  user_id: number

  @Column
  is_revoked: boolean
  
  @Column
  expires: Date
}

refresh-tokens.repository.ts

// app/modules/authentication/refresh-tokens.repository.ts

import { Injectable } from '@nestjs/common'
import { User } from '../../../models/user.model'
import { RefreshToken } from '../../../models/refresh-token.model'

@Injectable()
export class RefreshTokensRepository {
  public async createRefreshToken (user: User, ttl: number): Promise<RefreshToken> {
    const token = new RefreshToken()

    token.user_id = user.id
    token.is_revoked = false
    
    const expiration = new Date()
    expiration.setTime(expiration.getTime() + ttl)
    
    token.expires = expiration

    return token.save()
  }

  public async findTokenById (id: number): Promise<RefreshToken | null> {
    return RefreshToken.findOne({
      where: {
        id,
      }
    })
  }
}

requests.ts

// app/requests.ts

import { IsNotEmpty, MinLength } from 'class-validator'

export class LoginRequest {
  @IsNotEmpty({ message: 'A username is required' })
  readonly username: string

  @IsNotEmpty({ message: 'A password is required to login' })
  readonly password: string
}

export class RegisterRequest {
  @IsNotEmpty({ message: 'An username is required' })
  readonly username: string

  @IsNotEmpty({ message: 'A password is required' })
  @MinLength(6, { message: 'Your password must be at least 6 characters' })
  readonly password: string
}

export class RefreshRequest {
  @IsNotEmpty({ message: 'The refresh token is required' })
  readonly refresh_token: string
}

tokens-1.service.ts

// app/modules/authentication/tokens.service.ts

import { Injectable } from '@nestjs/common'
import { JwtService } from '@nestjs/jwt'
import { SignOptions } from 'jsonwebtoken'

import { User } from '../../models'

import { RefreshTokensRepository } from './refresh-tokens.repository'

const BASE_OPTIONS: SignOptions = {
  issuer: 'https://my-app.com',
  audience:'https://my-app.com',
}

@Injectable()
export class TokensService {
  private readonly tokens: RefreshTokensRepository
  private readonly jwt: JwtService

  public constructor (tokens: RefreshTokensRepository, jwt: JwtService) {
    this.tokens = tokens
    this.jwt = jwt
  }

  public async generateAccessToken (user: User): Promise<string> {
    const opts: SignOptions = {
      ...BASE_OPTIONS,
      subject: String(user.id),
    }

    return this.jwt.signAsync({}, opts)
  }

  public async generateRefreshToken (user: User, expiresIn: number): Promise<string> {
    const token = await this.tokens.createRefreshToken(user, expiresIn)

    const opts: SignOptions = {
      ...BASE_OPTIONS,
      expiresIn,
      subject: String(user.id),
      jwtid: String(token.id),
    }

    return this.jwt.signAsync({}, opts)
  }
}

tokens-2.service.ts

// app/modules/authentication/tokens.service.ts

import { UnprocessableEntityException, Injectable } from '@nestjs/common'
import { JwtService } from '@nestjs/jwt'
import { SignOptions, TokenExpiredError } from 'jsonwebtoken'

import { User } from '../../models'
import { RefreshToken } from '../../models/refresh-token.model'

import { UsersRepository } from '../users/users.repository'
import { RefreshTokensRepository } from './refresh-tokens.repository'

const BASE_OPTIONS: SignOptions = {
  issuer: 'https://my-app.com',
  audience:'https://my-app.com',
}

export interface RefreshTokenPayload {
  jti: number;
  sub: number
}

@Injectable()
export class TokensService {
  private readonly tokens: RefreshTokensRepository
  private readonly users: UsersRepository
  private readonly jwt: JwtService

  public constructor (tokens: RefreshTokensRepository, users: UsersRepository, jwt: JwtService) {
    this.tokens = tokens
    this.users = users
    this.jwt = jwt
  }

  public async generateAccessToken (user: User): Promise<string> {
    const opts: SignOptions = {
      ...BASE_OPTIONS,
      subject: String(user.id),
    }

    return this.jwt.signAsync({}, opts)
  }

  public async generateRefreshToken (user: User, expiresIn: number): Promise<string> {
    const token = await this.tokens.createRefreshToken(user, expiresIn)

    const opts: SignOptions = {
      ...BASE_OPTIONS,
      expiresIn,
      subject: String(user.id),
      jwtid: String(token.id),
    }

    return this.jwt.signAsync({}, opts)
  }

  public async resolveRefreshToken (encoded: string): Promise<{ user: User, token: RefreshToken }> {
    const payload = await this.decodeRefreshToken(encoded)
    const token = await this.getStoredTokenFromRefreshTokenPayload(payload)

    if (!token) {
      throw new UnprocessableEntityException('Refresh token not found')
    }

    if (token.is_revoked) {
      throw new UnprocessableEntityException('Refresh token revoked')
    }

    const user = await this.getUserFromRefreshTokenPayload(payload)

    if (!user) {
      throw new UnprocessableEntityException('Refresh token malformed')
    }

    return { user, token }
  }

  public async createAccessTokenFromRefreshToken (refresh: string): Promise<{ token: string, user: User }> {
    const { user } = await this.resolveRefreshToken(refresh)

    const token = await this.generateAccessToken(user)

    return { user, token }
  }
  
  private async decodeRefreshToken (token: string): Promise<RefreshTokenPayload> {
    try {
      return this.jwt.verifyAsync(token)
    } catch (e) {
      if (e instanceof TokenExpiredError) {
        throw new UnprocessableEntityException('Refresh token expired')
      } else {
        throw new UnprocessableEntityException('Refresh token malformed') 
      }
    }
  }

  private async getUserFromRefreshTokenPayload (payload: RefreshTokenPayload): Promise<User> {
    const subId = payload.sub

    if (!subId) {
      throw new UnprocessableEntityException('Refresh token malformed')
    }

    return this.users.findForId(subId)
  }

  private async getStoredTokenFromRefreshTokenPayload (payload: RefreshTokenPayload): Promise<RefreshToken | null> {
    const tokenId = payload.jti

    if (!tokenId) {
      throw new UnprocessableEntityException('Refresh token malformed')
    }

    return this.tokens.findTokenById(tokenId)
  }
}

user.model.ts

// app/models/user.model.ts

import { Column, Model, Table } from 'sequelize-typescript'

@Table({ tableName: 'users', underscored: true })
export class User extends Model<User> {
  @Column
  username: string

  @Column
  password: string
}

users.module.ts

// app/modules/users/users.module.ts

import { Module } from '@nestjs/common'
import { SequelizeModule } from '@nestjs/sequelize'

import { User } from '../../models/user'

import { UsersService } from './users.service'
import { UsersRepository } from './users.repository'

@Module({
  imports: [
    SequelizeModule.forFeature([
      User,
    ]),
  ],
  providers: [
    UsersService,
    UsersRepository,
  ],
  exports: [
    UsersService,
    UsersRepository,
  ],
})
export class UsersModule {}

users.repository.ts

// app/modules/users/users.repository.ts

import { Injectable } from '@nestjs/common'
import { InjectModel } from '@nestjs/sequelize'
import { hash } from 'bcrypt'
import { col, fn, where } from 'sequelize'
import { User } from '../../models'

@Injectable()
export class UsersRepository {
  private readonly users: typeof User

  public constructor (@InjectModel(User) users: typeof User) {
    this.users = users
  }

  public async findForId (id: number): Promise<User | null> {
    return this.users.findOne({
      where: {
        id,
      },
    })
  }

  public async findForUsername (username: string): Promise<User | null> {
    return this.users.findOne({
      where: {
        username: where(fn('lower', col('username')), username),
      },
    })
  }

  public async create (username: string, password: string): Promise<User> {
    const user = new User()

    user.username = username
    user.password = await hash(password, 10)

    return user.save()
  }
}

users.service.ts

// app/modules/user/users.service.ts

import { UnprocessableEntityException, Injectable } from '@nestjs/common'
import { compare } from 'bcrypt'

import { RegisterRequest } from '../../requests'

import { User } from '../../models'

import { UsersRepository } from '../users/users.repository'

@Injectable()
export class UsersService {
  private readonly users: UsersRepository

  public constructor (users: UsersRepository) {
    this.users = users
  }

  public async validateCredentials (user: User, password: string): Promise<boolean> {
    return compare(password, user.password)
  }

  public async createUserFromRequest (request: RegisterRequest): Promise<User> {
    const { username, password } = request

    const existingFromUsername = await this.findForUsername(request.username)

    if (existingFromUsername) {
      throw new UnprocessableEntityException('Username already in use')
    }

    return this.users.create(username, password)
  }

  public async findForId (id: number): Promise<User | null> {
    return this.users.findForId(id)
  }

  public async findForUsername (username: string): Promise<User | null> {
    return this.users.findForUsername(username)
  }

}