Go语言实现的JSON Web Token教程的实现

go get -u github.com/golang-jwt/jwt/v5

package main

import (
    "fmt"
    "time"

    "github.com/golang-jwt/jwt/v5"
)

var mySigningKey = []byte("secret_key")

func main() {
    token := jwt.NewWithClaims(jwt.SigningMethodHS256,
        jwt.MapClaims{
            "username": "johndoe",
            "exp":      time.Now().Add(time.Hour * 24).Unix(),
        })

    // Sign and get the complete encoded token as a string using the secret
    tokenString, err := token.SignedString(mySigningKey)
    if err != nil {
        fmt.Println(err.Error())
        return
    }

    // Simulate token validation
    var validToken *jwt.Token
    validToken, err = jwt.Parse(tokenString, func(token *jwt.Token) (interface{}, error) {
        // Don't forget to validate the alg is what you expect:
        if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
            return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
        }

        // Validate the secret
        return mySigningKey, nil
    })
    if claims, ok := validToken.Claims.(jwt.MapClaims); ok && validToken.Valid {
        fmt.Printf("Valid Token. Username: %v\n", claims["username"])
    } else {
        fmt.Println("Invalid Token")
    }
}