pkg/middleware/auth/auth.go

package auth

import (
	"fmt"
	"net/http"
	"time"

	"git.links123.net/links123.com/uc/app"
	"github.com/dgrijalva/jwt-go"
	"github.com/gin-gonic/gin"
)

const (
	CtxRequestHeaderUserId        = "user_id"
	ctxRequestHeaderAuthorization = "Authorization"
	ctxRequestCookieAuthorization = "ak"
	ctxRequestTokenExpired        = "expired"
)

func Auth(ctx *gin.Context) {
	var (
		err error
		tk  = ctx.Request.Header.Get(ctxRequestHeaderAuthorization)
	)

	if tk == "" {
		tk, err = ctx.Cookie(ctxRequestCookieAuthorization)
		if err != nil {
			ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"msg": "auth failed"})
			return
		}

		tk = "Bearer " + tk
	}

	if len(tk) < 8 {
		ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"msg": "auth failed"})
		return
	}

	token, err := jwt.Parse(tk[7:], func(token *jwt.Token) (interface{}, error) {
		if _, ok := token.Method.(*jwt.SigningMethodHMAC); !ok {
			return nil, fmt.Errorf("unexpected signing method: %v", token.Header["alg"])
		}

		return []byte(app.Config.Token.AuthKey), nil
	})

	if err != nil || !token.Valid {
		ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"msg": "auth failed"})
		return
	}

	mapClaims := token.Claims.(jwt.MapClaims)
	expired := int64(mapClaims[ctxRequestTokenExpired].(float64))
	if expired < time.Now().Unix() {
		// Only cookie is blank value, check token expired
		if _, err := ctx.Cookie(ctxRequestCookieAuthorization); err != nil {
			ctx.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"msg": "auth failed, token timeout"})
			return
		}
	}

	ctx.Set(CtxRequestHeaderUserId, int(mapClaims[CtxRequestHeaderUserId].(float64)))
}