在使用 gorilla session Web 工具包时，不会跨请求维护 session 变量。 当我启动服务器并键入 localhost:8100/时，页面被定向到 login.html，因为 session 值不存在。登录后，我在商店中设置 session 变量，页面被重定向到 home.html。但是，当我打开一个新选项卡并键入 localhost:8100/时，该页面应该使用已存储的 session 变量定向到 home.html，但该页面改为重定向到 login.html。 以下是代码。

    package main

import (
    "crypto/md5"
    "encoding/hex"
    "fmt"
    "github.com/gocql/gocql"
    "github.com/gorilla/mux"
    "github.com/gorilla/sessions"
    "net/http"
    "time"
)

var store = sessions.NewCookieStore([]byte("something-very-secret"))

var router = mux.NewRouter()

func init() {

    store.Options = &sessions.Options{
        Domain:   "localhost",
        Path:     "/",
        MaxAge:   3600 * 1, // 1 hour
        HttpOnly: true,
    }
}
func main() {
    //session handling
    router.HandleFunc("/", SessionHandler)
    router.HandleFunc("/signIn", SignInHandler)
    router.HandleFunc("/signUp", SignUpHandler)
    router.HandleFunc("/logOut", LogOutHandler)
    http.Handle("/", router)
    http.ListenAndServe(":8100", nil)
}

//handler for signIn
func SignInHandler(res http.ResponseWriter, req *http.Request) {

    email := req.FormValue("email")
    password := req.FormValue("password")

    //Generate hash of password
    hasher := md5.New()
    hasher.Write([]byte(password))
    encrypted_password := hex.EncodeToString(hasher.Sum(nil))

    //cassandra connection
    cluster := gocql.NewCluster("localhost")
    cluster.Keyspace = "gbuy"
    cluster.DefaultPort = 9042
    cluster.Consistency = gocql.Quorum
    session, _ := cluster.CreateSession()
    defer session.Close()

    //select query
    var firstname string
    stmt := "SELECT firstname FROM USER WHERE email= '" + email + "' and password ='" + encrypted_password + "';"
    err := session.Query(stmt).Scan(&firstname)
    if err != nil {
        fmt.Fprintf(res, "failed")
    } else {
        if firstname == "" {
            fmt.Fprintf(res, "failed")
        } else {
            fmt.Fprintf(res, firstname)
        }
    }

    //store in session variable
    sessionNew, _ := store.Get(req, "loginSession")

    // Set some session values.
    sessionNew.Values["email"] = email
    sessionNew.Values["name"] = firstname

    // Save it.
    sessionNew.Save(req, res)
    //store.Save(req,res,sessionNew)

    fmt.Println("Session after logging:")
    fmt.Println(sessionNew)

}

//handler for signUp
func SignUpHandler(res http.ResponseWriter, req *http.Request) {

    fName := req.FormValue("fName")
    lName := req.FormValue("lName")
    email := req.FormValue("email")
    password := req.FormValue("passwd")
    birthdate := req.FormValue("date")
    city := req.FormValue("city")
    gender := req.FormValue("gender")

    //Get current timestamp and format it.
    sysdate := time.Now().Format("2006-01-02 15:04:05-0700")

    //Generate hash of password
    hasher := md5.New()
    hasher.Write([]byte(password))
    encrypted_password := hex.EncodeToString(hasher.Sum(nil))

    //cassandra connection
    cluster := gocql.NewCluster("localhost")
    cluster.Keyspace = "gbuy"
    cluster.DefaultPort = 9042
    cluster.Consistency = gocql.Quorum
    session, _ := cluster.CreateSession()
    defer session.Close()

    //Insert the data into the Table
    stmt := "INSERT INTO USER (email,firstname,lastname,birthdate,city,gender,password,creation_date) VALUES ('" + email + "','" + fName + "','" + lName + "','" + birthdate + "','" + city + "','" + gender + "','" + encrypted_password + "','" + sysdate + "');"
    fmt.Println(stmt)
    err := session.Query(stmt).Exec()
    if err != nil {
        fmt.Fprintf(res, "failed")
    } else {
        fmt.Fprintf(res, fName)
    }
}

//handler for logOut
func LogOutHandler(res http.ResponseWriter, req *http.Request) {
    sessionOld, err := store.Get(req, "loginSession")

    fmt.Println("Session in logout")
    fmt.Println(sessionOld)
    if err = sessionOld.Save(req, res); err != nil {
        fmt.Println("Error saving session: %v", err)
    }
}

//handler for Session
func SessionHandler(res http.ResponseWriter, req *http.Request) {

    router.PathPrefix("/").Handler(http.FileServer(http.Dir("../static/")))
    session, _ := store.Get(req, "loginSession")

    fmt.Println("Session in SessionHandler")
    fmt.Println(session)


    if val, ok := session.Values["email"].(string); ok {
        // if val is a string
        switch val {
        case "": {
            http.Redirect(res, req, "html/login.html", http.StatusFound) }
        default:
            http.Redirect(res, req, "html/home.html", http.StatusFound)
        }
    } else {
        // if val is not a string type
        http.Redirect(res, req, "html/login.html", http.StatusFound)
    }
}

谁能告诉我我做错了什么。提前致谢。

最佳答案

首先:你永远不应该使用 md5 来散列密码。 Read this article 为什么，然后使用 Go 的 bcrypt package 。您还应该 parameterise your SQL queries 否则您将面临 灾难性 SQL 注入(inject)攻击。

无论如何:这里有几个问题需要解决:

• 您的 session 没有“坚持”是因为您将 Path 设置为 /loginSession - 所以当用户访问任何其他路径时(即 /)， session 对该范围无效。

您应该在程序初始化时设置 session 存储并在那里设置选项:

var store = sessions.NewCookieStore([]byte("something-very-secret"))

func init() {

   store.Options = &sessions.Options{
    Domain:   "localhost",
    Path:     "/",
    MaxAge:   3600 * 8, // 8 hours
    HttpOnly: true,
}

您可能会设置更具体的路径的原因是，如果登录用户始终位于 /accounts 之类的子路径中。在你的情况下，这不是正在发生的事情。

我应该补充一点，Chrome 在 Web Inspector 中的“资源”选项卡(资源 > Cookie)对于调试此类问题非常有用，因为您可以看到 cookie 过期、路径和其他设置。

• 您还检查了 session.Values["email"] == nil，这不起作用。 Go中的空字符串就是""，因为session.Values是map[string]interface{}，所以需要type assert字符串的值:

即

if val, ok := session.Values["email"].(string); ok {
      // if val is a string
      switch val {
             case "":
                 http.Redirect(res, req, "html/login.html", http.StatusFound)
             default:
                 http.Redirect(res, req, "html/home.html", http.StatusFound)
      }
    } else {
        // if val is not a string type
        http.Redirect(res, req, "html/login.html", http.StatusFound)
    }

我们处理“不是字符串”的情况，所以如果 session 不是我们所期望的(客户端修改了它，或者我们的程序的旧版本使用了不同的类型)，我们会明确说明程序应该做什么。

• 您在保存 session 时没有检查错误。

  sessionNew.Save(req, res)
  

...应该是:

    err := sessionNew.Save(req, res)
    if err != nil {
            // handle the error case
    }

• 您应该在 SessionHandler 提供静态文件之前获取/验证 session (不过，您这样做的方式非常迂回):

  func SessionHandler(res http.ResponseWriter, req *http.Request) {
      session, err := store.Get(req, "loginSession")
      if err != nil {
          // Handle the error
      }
  
      if session.Values["email"] == nil {
          http.Redirect(res, req, "html/login.html", http.StatusFound)
      } else {
         http.Redirect(res, req, "html/home.html", http.StatusFound)
      }
      // This shouldn't be here - router isn't scoped in this function! You should set this in your main() and wrap it with a function that checks for a valid session.
      router.PathPrefix("/").Handler(http.FileServer(http.Dir("../static/")))
  }
  

关于使用 gorilla session 时未保存 golang 中的 session 变量，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21865681/