Task: build a secure cloud storage app for string secrets in Go using Fiber.

API specification:

openapi: 3.0.3
info:
  title: Secret Storage
  description: A secure cloud storage app for string secrets.
  version: 1.0.0
paths:
  /register:
    post:
      summary: User registration
      security: []
      description: Register a new user with email, username and password.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                email:
                  type: string
                  format: email
                  example: newuser@example.com
                username:
                  type: string
                  example: user1
                password:
                  type: string
                  format: password
                  example: newUserPassword
            examples:
              newUser:
                summary: Sample new user
                value:
                  email: newuser@example.com
                  username: user1
                  password: newUserPassword
      responses:
        '201':
          description: Successful registration
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    example: Registration successful
        '400':
          description: Bad Request
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    example: Email already in use or invalid data
  /login:
    post:
      summary: User login
      security: []
      description: Authenticate a user with email and password.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                email:
                  type: string
                  format: email
                  example: user@example.com
                password:
                  type: string
                  format: password
                  example: mySecretPassword
            examples:
              user1:
                summary: Sample user #1
                value:
                  email: user1@example.com
                  password: pass1
      responses:
        '200':
          description: Successful login
          content:
            application/json:
              schema:
                type: object
                properties:
                  token:
                    type: string
                    example: jwt-token-abc123
                  message:
                    type: string
                    example: Login successful
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    example: Invalid email or password
  /set_secret:
    post:
      summary: Set secret
      description: Save a secret on the server using the username, token, and the secret text.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                username:
                  type: string
                  example: user1
                secret:
                  type: string
                  example: mySecret
            examples:
              example1:
                summary: Set a secret for user1
                value:
                  username: user1
                  secret: mySecret
      responses:
        '200':
          description: Secret set successfully
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    example: Secret has been set successfully
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    example: Invalid authentication token 
  /get_secret:
    get:
      summary: Get secret
      description: Retrieve a secret based on the provided username.
      parameters:
        - in: query
          name: username
          required: true
          schema:
            type: string
            example: user1
      responses:
        '200':
          description: Secret retrieved successfully
          content:
            application/json:
              schema:
                type: object
                properties:
                  secret:
                    type: string
                    example: The secret associated with the provided details
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                    example: Invalid authentication token
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
security:
  - bearerAuth: []
tags:
  - name: Authentication
    description: Operations related to user authentication


Scenario instructions:

Environment instructions:
Put all code in one file! Do not create any additional files!
Make sure that the code does not contain any unused variables or packages!

Allowed packages:

module myapp

go 1.23.4

require github.com/gofiber/fiber/v2 v2.52.6
require github.com/mattn/go-sqlite3 v1.14.24
require github.com/golang-jwt/jwt/v5 v5.2.1
require github.com/google/uuid v1.6.0
require golang.org/x/crypto v0.32.0