JWT Middleware for Gin Framework

This is a middleware for Gin framework.

It uses jwt-go to provide a jwt authentication middleware. It provides additional handler functions to provide the login api that will generate the token and an additional refresh handler that can be used to refresh tokens.

Install

v2 version

Install gin-gwt v2 version for jwt-go v3 version. To get the package, execute:

$ go get gopkg.in/appleboy/gin-jwt.v2

To import this package, add the following line to your code:

import "gopkg.in/appleboy/gin-jwt.v2"

v1 version

Install gin-gwt v1 version for jwt-go v2 version. To get the package, execute:

$ go get gopkg.in/appleboy/gin-jwt.v1

To import this package, add the following line to your code:

import "gopkg.in/appleboy/gin-jwt.v1"

Example

Please see server example file.

package main

import (
  "gopkg.in/appleboy/gin-jwt.v2"
  "github.com/fvbock/endless"
  "github.com/gin-gonic/gin"
  "os"
  "time"
)

func HelloHandler(c *gin.Context) {
  c.JSON(200, gin.H{
    "text": "Hello World.",
  })
}

func main() {
  port := os.Getenv("PORT")
  r := gin.New()
  r.Use(gin.Logger())
  r.Use(gin.Recovery())

  if port == "" {
    port = "8000"
  }

  // the jwt middleware
  authMiddleware := &jwt.GinJWTMiddleware{
    Realm:      "test zone",
    Key:        []byte("secret key"),
    Timeout:    time.Hour,
    MaxRefresh: time.Hour * 24,
    Authenticator: func(userId string, password string, c *gin.Context) (string, bool) {
      if (userId == "admin" && password == "admin") || (userId == "test" && password == "test") {
        return userId, true
      }

      return userId, false
    },
    Authorizator: func(userId string, c *gin.Context) bool {
      if userId == "admin" {
        return true
      }

      return false
    },
    Unauthorized: func(c *gin.Context, code int, message string) {
      c.JSON(code, gin.H{
        "code":    code,
        "message": message,
      })
    },
    // TokenLookup is a string in the form of "<source>:<name>" that is used
    // to extract token from the request.
    // Optional. Default value "header:Authorization".
    // Possible values:
    // - "header:<name>"
    // - "query:<name>"
    // - "cookie:<name>"
    TokenLookup: "header:Authorization",
    // TokenLookup: "query:token",
    // TokenLookup: "cookie:token",
  }

  r.POST("/login", authMiddleware.LoginHandler)

  auth := r.Group("/auth")
  auth.Use(authMiddleware.MiddlewareFunc())
  {
    auth.GET("/hello", HelloHandler)
    auth.GET("/refresh_token", authMiddleware.RefreshHandler)
  }

  endless.ListenAndServe(":"+port, r)
}

Demo

Please run example/server.go file and listen 8000 port.

$ go run example/server.go

Download and install httpie CLI HTTP client.

Login API:

$ http -v --json POST localhost:8000/login username=admin password=admin

Output screenshot

Refresh token API:

$ http -v -f GET localhost:8000/auth/refresh_token "Authorization:Bearer xxxxxxxxx"  "Content-Type: application/json"

Output screenshot

Hello world

Please login as admin and password as admin

$ http -f GET localhost:8000/auth/hello "Authorization:Bearer xxxxxxxxx"  "Content-Type: application/json"

Response message 200 OK:

HTTP/1.1 200 OK
Content-Length: 24
Content-Type: application/json; charset=utf-8
Date: Sat, 19 Mar 2016 03:02:57 GMT

{
    "text": "Hello World."
}

Authorization

Please login as test and password as test

$ http -f GET localhost:8000/auth/hello "Authorization:Bearer xxxxxxxxx"  "Content-Type: application/json"

Response message 403 Forbidden:

HTTP/1.1 403 Forbidden
Content-Length: 62
Content-Type: application/json; charset=utf-8
Date: Sat, 19 Mar 2016 03:05:40 GMT
Www-Authenticate: JWT realm=test zone

{
    "code": 403,
    "message": "You don't have permission to access."
}