【go】JWT 在beego中的运用

超、凢脫俗 2022-01-30 07:21 330阅读 0赞

首先我们要知道jwt的概念, json web token 用户client 与server端的认证，包含三部分： head payload signature。  
详情看这个： [https://jwt.io/][https_jwt.io] 或者 [ruanyf的文章][ruanyf]

直接上go的代码, utils/token.go：

package utils
    
    import (
    	"fmt"
    	"github.com/dgrijalva/jwt-go"
    	"time"
    )
    
    const (
    	KEY string = "JWT-ARY-STARK"
    	DEFAULT_EXPIRE_SECONDS int = 600 // default 10 minutes
    
    )
    
    type User struct { 
    	Id string `json:"id"`
    	Name string `json:"json"`
    }
    
    
    // JWT -- json web token
    // HEADER PAYLOAD SIGNATURE
    // This struct is the PAYLOAD
    type MyCustomClaims struct { 
    	User
    	jwt.StandardClaims
    }
    
    
    // update expireAt and return a new token
    func RefreshToken(tokenString string)(string, error) { 
    	// first get previous token
    	token, err := jwt.ParseWithClaims(
    		tokenString,
    		&MyCustomClaims{ },
    		func(token *jwt.Token)(interface{ }, error) { 
    			return []byte(KEY), nil
    		})
    	claims, ok := token.Claims.(*MyCustomClaims)
    	if !ok || !token.Valid { 
    		return "", err
    	}
    	mySigningKey := []byte(KEY)
    	expireAt  := time.Now().Add(time.Second * time.Duration(DEFAULT_EXPIRE_SECONDS)).Unix()
    	newClaims := MyCustomClaims{ 
    		claims.User,
    		jwt.StandardClaims{ 
    			ExpiresAt: expireAt,
    			Issuer:    claims.User.Name,
    			IssuedAt:  time.Now().Unix(),
    		},
    	}
    	// generate new token with new claims
    	newToken := jwt.NewWithClaims(jwt.SigningMethodHS256, newClaims)
    	tokenStr, err := newToken.SignedString(mySigningKey)
    	if err != nil { 
    		fmt.Println("generate new fresh json web token failed !! error :", err)
    		return  "" , err
    	}
    	return tokenStr, err
    }
    
    
    func ValidateToken(tokenString string) error { 
    	token, err := jwt.ParseWithClaims(
    		tokenString,
    		&MyCustomClaims{ },
    		func(token *jwt.Token)(interface{ }, error) { 
    			return []byte(KEY), nil
    		})
    	if claims, ok := token.Claims.(*MyCustomClaims); ok && token.Valid { 
    		fmt.Printf("%v %v", claims.User, claims.StandardClaims.ExpiresAt)
    		fmt.Println("token will be expired at ", time.Unix(claims.StandardClaims.ExpiresAt, 0))
    	} else { 
    		fmt.Println("validate tokenString failed !!!",err)
    		return err
    	}
    	return nil
    }
    
    
    func GenerateToken(expiredSeconds int) (tokenString string) { 
    	 if expiredSeconds == 0 { 
    	 	expiredSeconds = DEFAULT_EXPIRE_SECONDS
    	 }
    	// Create the Claims
    	mySigningKey := []byte(KEY)
    	expireAt  := time.Now().Add(time.Second * time.Duration(expiredSeconds)).Unix()
    	fmt.Println("token will be expired at ", time.Unix(expireAt, 0) )
    	// pass parameter to this func or not
    	user := User{ "007", "Kev"}
    	claims := MyCustomClaims{ 
    		user,
    		jwt.StandardClaims{ 
    			ExpiresAt: expireAt,
    			Issuer:    user.Name,
    			IssuedAt:  time.Now().Unix(),
    		},
    	}
    	token := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)
    	tokenStr, err := token.SignedString(mySigningKey)
    	if err != nil { 
    		fmt.Println("generate json web token failed !! error :", err)
    	}
    	return tokenStr
    
    }
    
    // return this result to client then all later request should have header "Authorization: Bearer <token> "
    func getHeaderTokenValue(tokenString string) string { 
    	//Authorization: Bearer <token>
    	return fmt.Sprintf("Bearer %s", tokenString)
    }

下一步我们给beego添加一个过滤器，假定：login接口返回给client 一个token，后续所有的请求都会带上这个token：

var FilterToken = func(ctx *context.Context) { 
    	logs.Info("current router path is ", ctx.Request.RequestURI)
    	if ctx.Request.RequestURI != "/login" && ctx.Input.Header("Authorization") == "" { 
    		logs.Error("without token, unauthorized !!")
    		ctx.ResponseWriter.WriteHeader(401)
    		ctx.ResponseWriter.Write([]byte("no permission"))
    	}
    	if ctx.Request.RequestURI != "/login" && ctx.Input.Header("Authorization") != "" { 
    		token := ctx.Input.Header("Authorization")
    		token = strings.Split(token, "")[1]
    		logs.Info("curernttoken: ", token)
    		// validate token
    		// invoke ValidateToken in utils/token
    		// invalid or expired todo res 401
    	}
    }

到这一步就完成了，不一定是beego可以是其他web框架都能使用utils/token.go里面的方法。

[https_jwt.io]: https://jwt.io/
[ruanyf]: http://www.ruanyifeng.com/blog/2018/07/json_web_token-tutorial.html