## JWT
- JWT 使用 HS256 算法認證。
- JWT 從 `Authorization` 請求頭取出數據。
### 服務端（使用 map）
`server.go`
```go
package main
import (
"net/http"
"time"
jwt "github.com/dgrijalva/jwt-go"
"github.com/labstack/echo"
"github.com/labstack/echo/middleware"
)
func login(c echo.Context) error {
username := c.FormValue("username")
password := c.FormValue("password")
if username == "jon" && password == "shhh!" {
// Create token
token := jwt.New(jwt.SigningMethodHS256)
// Set claims
claims := token.Claims.(jwt.MapClaims)
claims["name"] = "Jon Snow"
claims["admin"] = true
claims["exp"] = time.Now().Add(time.Hour * 72).Unix()
// Generate encoded token and send it as response.
t, err := token.SignedString([]byte("secret"))
if err != nil {
return err
}
return c.JSON(http.StatusOK, map[string]string{
"token": t,
})
}
return echo.ErrUnauthorized
}
func accessible(c echo.Context) error {
return c.String(http.StatusOK, "Accessible")
}
func restricted(c echo.Context) error {
user := c.Get("user").(*jwt.Token)
claims := user.Claims.(jwt.MapClaims)
name := claims["name"].(string)
return c.String(http.StatusOK, "Welcome "+name+"!")
}
func main() {
e := echo.New()
// Middleware
e.Use(middleware.Logger())
e.Use(middleware.Recover())
// Login route
e.POST("/login", login)
// Unauthenticated route
e.GET("/", accessible)
// Restricted group
r := e.Group("/restricted")
r.Use(middleware.JWT([]byte("secret")))
r.GET("", restricted)
e.Logger.Fatal(e.Start(":1323"))
}
```
### 服務端（使用結構體）
`server.go`
```go
package main
import (
"net/http"
"time"
jwt "github.com/dgrijalva/jwt-go"
"github.com/labstack/echo"
"github.com/labstack/echo/middleware"
)
// jwtCustomClaims are custom claims extending default ones.
type jwtCustomClaims struct {
Name string `json:"name"`
Admin bool `json:"admin"`
jwt.StandardClaims
}
func login(c echo.Context) error {
username := c.FormValue("username")
password := c.FormValue("password")
if username == "jon" && password == "shhh!" {
// Set custom claims
claims := &jwtCustomClaims{
"Jon Snow",
true,
jwt.StandardClaims{
ExpiresAt: time.Now().Add(time.Hour * 72).Unix(),
},
}
// Create token with claims
token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
// Generate encoded token and send it as response.
t, err := token.SignedString([]byte("secret"))
if err != nil {
return err
}
return c.JSON(http.StatusOK, echo.Map{
"token": t,
})
}
return echo.ErrUnauthorized
}
func accessible(c echo.Context) error {
return c.String(http.StatusOK, "Accessible")
}
func restricted(c echo.Context) error {
user := c.Get("user").(*jwt.Token)
claims := user.Claims.(*jwtCustomClaims)
name := claims.Name
return c.String(http.StatusOK, "Welcome "+name+"!")
}
func main() {
e := echo.New()
// Middleware
e.Use(middleware.Logger())
e.Use(middleware.Recover())
// Login route
e.POST("/login", login)
// Unauthenticated route
e.GET("/", accessible)
// Restricted group
r := e.Group("/restricted")
// Configure middleware with the custom claims type
config := middleware.JWTConfig{
Claims: &jwtCustomClaims{},
SigningKey: []byte("secret"),
}
r.Use(middleware.JWTWithConfig(config))
r.GET("", restricted)
e.Logger.Fatal(e.Start(":1323"))
}
```
### 客戶端
`curl`
#### 登錄
使用賬號和密碼登錄獲取 token。
```sh
curl -X POST -d 'username=jon' -d 'password=shhh!' localhost:1323/login
```
*返回*
```js
{
"token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0NjE5NTcxMzZ9.RB3arc4-OyzASAaUhC2W3ReWaXAt_z2Fd3BN4aWTgEY"
}
```
#### 請求
在 `Authorization` 請求頭設置 token，發送請求獲取資源。
```sh
curl localhost:1323/restricted -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJleHAiOjE0NjE5NTcxMzZ9.RB3arc4-OyzASAaUhC2W3ReWaXAt_z2Fd3BN4aWTgEY"
```
*返回*
```
Welcome Jon Snow!
```
