Golang用户认证系统实现教程

package models
type User struct {
ID       uint   gorm:"primaryKey"
Username string gorm:"unique;not null"
Password string gorm:"not null"
}

package database
import (
"gorm.io/driver/sqlite"
"gorm.io/gorm"
)
var DB *gorm.DB
func Init() {
var err error
DB, err = gorm.Open(sqlite.Open("users.db"), &gorm.Config{})
if err != nil {
panic("failed to connect database")
}
DB.AutoMigrate(&User{})
}

func Register(c *gin.Context) {
  var user models.User
  if err := c.ShouldBindJSON(&user); err != nil {
    c.JSON(400, gin.H{"error": "invalid input"})
    return
  }
hashedPassword, _ := utils.HashPassword(user.Password)
user.Password = hashedPassword
if err := database.DB.Create(&user).Error; err != nil {
c.JSON(400, gin.H{"error": "username already exists"})
return
}
c.JSON(201, gin.H{"message": "user created"})
}

func Login(c *gin.Context) {
  var input models.User
  if err := c.ShouldBindJSON(&input); err != nil {
    c.JSON(400, gin.H{"error": "invalid input"})
    return
  }
var user models.User
if err := database.DB.Where("username = ?", input.Username).First(&user).Error; err != nil {
c.JSON(401, gin.H{"error": "invalid credentials"})
return
}
if !utils.CheckPasswordHash(input.Password, user.Password) {
c.JSON(401, gin.H{"error": "invalid credentials"})
return
}
token, err := utils.GenerateJWT(user.Username)
if err != nil {
c.JSON(500, gin.H{"error": "could not generate token"})
return
}
c.JSON(200, gin.H{"token": token})
}

package middleware
import (
"net/http"
"strings"
"github.com/dgrijalva/jwt-go"
"github.com/gin-gonic/gin"
)
var jwtKey = []byte("my_secret_key")
func AuthMiddleware() gin.HandlerFunc {
return func(c *gin.Context) {
authHeader := c.GetHeader("Authorization")
if authHeader == "" {
c.JSON(401, gin.H{"error": "missing authorization header"})
c.Abort()
return
}
tokenString := strings.TrimPrefix(authHeader, "Bearer ")
claims := &jwt.StandardClaims{}

token, err := jwt.ParseWithClaims(tokenString, claims, func(token *jwt.Token) (interface{}, error) {
  return jwtKey, nil
})

if err != nil || !token.Valid {
  c.JSON(401, gin.H{"error": "invalid or expired token"})
  c.Abort()
  return
}

c.Set("username", claims.Subject)
c.Next()
}
}

router.GET("/protected", middleware.AuthMiddleware(), func(c *gin.Context) {
  username := c.MustGet("username").(string)
  c.JSON(200, gin.H{"message": "hello " + username})
})

package utils
import (
"time"
"github.com/dgrijalva/jwt-go"
)
var jwtKey = []byte("my_secret_key")
func GenerateJWT(username string) (string, error) {
claims := &jwt.StandardClaims{
Subject:   username,
ExpiresAt: time.Now().Add(24 * time.Hour).Unix(),
}
token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
return token.SignedString(jwtKey)
}

package utils
import (
"golang.org/x/crypto/bcrypt"
)
func HashPassword(password string) (string, error) {
bytes, err := bcrypt.GenerateFromPassword([]byte(password), 12)
return string(bytes), err
}
func CheckPasswordHash(password, hash string) bool {
err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
return err == nil
}