在開發(fā)Web應(yīng)用過(guò)程中，用戶認(rèn)證是開發(fā)者經(jīng)常遇到的問(wèn)題，用戶登錄、注冊(cè)、登出等操作，而一般認(rèn)證也分為三個(gè)方面的認(rèn)證

• HTTP Basic和 HTTP Digest認(rèn)證
• 第三方集成認(rèn)證：QQ、微博、豆瓣、OPENID、google、github、facebook和twitter等
• 自定義的用戶登錄、注冊(cè)、登出，一般都是基于session、cookie認(rèn)證

beego目前沒(méi)有針對(duì)這三種方式進(jìn)行任何形式的集成，但是可以充分的利用第三方開源庫(kù)來(lái)實(shí)現(xiàn)上面的三種方式的用戶認(rèn)證，不過(guò)后續(xù)beego會(huì)對(duì)前面兩種認(rèn)證逐步集成。

HTTP Basic和 HTTP Digest認(rèn)證

這兩個(gè)認(rèn)證是一些應(yīng)用采用的比較簡(jiǎn)單的認(rèn)證，目前已經(jīng)有開源的第三方庫(kù)支持這兩個(gè)認(rèn)證：

github.com/abbot/go-http-auth 

下面代碼演示了如何把這個(gè)庫(kù)引入beego中從而實(shí)現(xiàn)認(rèn)證：

package controllers

import (
    "github.com/abbot/go-http-auth"
    "github.com/astaxie/beego"
)

func Secret(user, realm string) string {
    if user == "john" {
        // password is "hello"
        return "$1$dlPL2MqE$oQmn16q49SqdmhenQuNgs1"
    }
    return ""
}

type MainController struct {
    beego.Controller
}

func (this *MainController) Prepare() {
    a := auth.NewBasicAuthenticator("example.com", Secret)
    if username := a.CheckAuth(this.Ctx.Request); username == "" {
        a.RequireAuth(this.Ctx.ResponseWriter, this.Ctx.Request)
    }
}

func (this *MainController) Get() {
    this.Data["Username"] = "astaxie"
    this.Data["Email"] = "astaxie@gmail.com"
    this.TplNames = "index.tpl"
}

上面代碼利用了beego的prepare函數(shù)，在執(zhí)行正常邏輯之前調(diào)用了認(rèn)證函數(shù)，這樣就非常簡(jiǎn)單的實(shí)現(xiàn)了http auth，digest的認(rèn)證也是同樣的原理。

oauth和oauth2的認(rèn)證

oauth和oauth2是目前比較流行的兩種認(rèn)證方式，還好第三方有一個(gè)庫(kù)實(shí)現(xiàn)了這個(gè)認(rèn)證，但是是國(guó)外實(shí)現(xiàn)的，并沒(méi)有QQ、微博之類的國(guó)內(nèi)應(yīng)用認(rèn)證集成：

github.com/bradrydzewski/go.auth

下面代碼演示了如何把該庫(kù)引入beego中從而實(shí)現(xiàn)oauth的認(rèn)證，這里以github為例演示：

1. 添加兩條路由

     beego.RegisterController("/auth/login", &controllers.GithubController{})
     beego.RegisterController("/mainpage", &controllers.PageController{})

2. 然后我們處理GithubController登陸的頁(yè)面：

     package controllers
   
     import (
         "github.com/astaxie/beego"
         "github.com/bradrydzewski/go.auth"
     )
   
     const (
         githubClientKey = "a0864ea791ce7e7bd0df"
         githubSecretKey = "a0ec09a647a688a64a28f6190b5a0d2705df56ca"
     )
   
     type GithubController struct {
         beego.Controller
     }
   
     func (this *GithubController) Get() {
         // set the auth parameters
         auth.Config.CookieSecret = []byte("7H9xiimk2QdTdYI7rDddfJeV")
         auth.Config.LoginSuccessRedirect = "/mainpage"
         auth.Config.CookieSecure = false
   
         githubHandler := auth.Github(githubClientKey, githubSecretKey)
   
         githubHandler.ServeHTTP(this.Ctx.ResponseWriter, this.Ctx.Request)
     }

3. 處理登陸成功之后的頁(yè)面

     package controllers
   
     import (
         "github.com/astaxie/beego"
         "github.com/bradrydzewski/go.auth"
         "net/http"
         "net/url"
     )
   
     type PageController struct {
         beego.Controller
     }
   
     func (this *PageController) Get() {
         // set the auth parameters
         auth.Config.CookieSecret = []byte("7H9xiimk2QdTdYI7rDddfJeV")
         auth.Config.LoginSuccessRedirect = "/mainpage"
         auth.Config.CookieSecure = false
   
         user, err := auth.GetUserCookie(this.Ctx.Request)
   
         //if no active user session then authorize user
         if err != nil || user.Id() == "" {
             http.Redirect(this.Ctx.ResponseWriter, this.Ctx.Request, auth.Config.LoginRedirect, http.StatusSeeOther)
             return
         }
   
         //else, add the user to the URL and continue
         this.Ctx.Request.URL.User = url.User(user.Id())
         this.Data["pic"] = user.Picture()
         this.Data["id"] = user.Id()
         this.Data["name"] = user.Name()
         this.TplNames = "home.tpl"
     }

整個(gè)的流程如下，首先打開瀏覽器輸入地址：

http://wiki.jikexueyuan.com/project/go-web-programming/images/14.4.github.png" alt="" />

圖14.4 顯示帶有登錄按鈕的首頁(yè)

然后點(diǎn)擊鏈接出現(xiàn)如下界面：

http://wiki.jikexueyuan.com/project/go-web-programming/images/14.4.github2.png" alt="" />

圖14.5 點(diǎn)擊登錄按鈕后顯示github的授權(quán)頁(yè)

然后點(diǎn)擊Authorize app就出現(xiàn)如下界面：

http://wiki.jikexueyuan.com/project/go-web-programming/images/14.4.github3.png" alt="" />

圖14.6 授權(quán)登錄之后顯示的獲取到的github信息頁(yè)

自定義認(rèn)證

自定義的認(rèn)證一般都是和session結(jié)合驗(yàn)證的，如下代碼來(lái)源于一個(gè)基于beego的開源博客：

//登陸處理
func (this *LoginController) Post() {
    this.TplNames = "login.tpl"
    this.Ctx.Request.ParseForm()
    username := this.Ctx.Request.Form.Get("username")
    password := this.Ctx.Request.Form.Get("password")
    md5Password := md5.New()
    io.WriteString(md5Password, password)
    buffer := bytes.NewBuffer(nil)
    fmt.Fprintf(buffer, "%x", md5Password.Sum(nil))
    newPass := buffer.String()

    now := time.Now().Format("2006-01-02 15:04:05")

    userInfo := models.GetUserInfo(username)
    if userInfo.Password == newPass {
        var users models.User
        users.Last_logintime = now
        models.UpdateUserInfo(users)

        //登錄成功設(shè)置session
        sess := globalSessions.SessionStart(this.Ctx.ResponseWriter, this.Ctx.Request)
        sess.Set("uid", userInfo.Id)
        sess.Set("uname", userInfo.Username)

        this.Ctx.Redirect(302, "/")
    }   
}

//注冊(cè)處理
func (this *RegController) Post() {
    this.TplNames = "reg.tpl"
    this.Ctx.Request.ParseForm()
    username := this.Ctx.Request.Form.Get("username")
    password := this.Ctx.Request.Form.Get("password")
    usererr := checkUsername(username)
    fmt.Println(usererr)
    if usererr == false {
        this.Data["UsernameErr"] = "Username error, Please to again"
        return
    }

    passerr := checkPassword(password)
    if passerr == false {
        this.Data["PasswordErr"] = "Password error, Please to again"
        return
    }

    md5Password := md5.New()
    io.WriteString(md5Password, password)
    buffer := bytes.NewBuffer(nil)
    fmt.Fprintf(buffer, "%x", md5Password.Sum(nil))
    newPass := buffer.String()

    now := time.Now().Format("2006-01-02 15:04:05")

    userInfo := models.GetUserInfo(username)

    if userInfo.Username == "" {
        var users models.User
        users.Username = username
        users.Password = newPass
        users.Created = now
        users.Last_logintime = now
        models.AddUser(users)

        //登錄成功設(shè)置session
        sess := globalSessions.SessionStart(this.Ctx.ResponseWriter, this.Ctx.Request)
        sess.Set("uid", userInfo.Id)
        sess.Set("uname", userInfo.Username)
        this.Ctx.Redirect(302, "/")
    } else {
        this.Data["UsernameErr"] = "User already exists"
    }

}

func checkPassword(password string) (b bool) {
    if ok, _ := regexp.MatchString("^[a-zA-Z0-9]{4,16}$", password); !ok {
        return false
    }
    return true
}

func checkUsername(username string) (b bool) {
    if ok, _ := regexp.MatchString("^[a-zA-Z0-9]{4,16}$", username); !ok {
        return false
    }
    return true
}

有了用戶登陸和注冊(cè)之后，其他模塊的地方可以增加如下這樣的用戶是否登陸的判斷：

func (this *AddBlogController) Prepare() {
    sess := globalSessions.SessionStart(this.Ctx.ResponseWriter, this.Ctx.Request)
    sess_uid := sess.Get("userid")
    sess_username := sess.Get("username")
    if sess_uid == nil {
        this.Ctx.Redirect(302, "/admin/login")
        return
    }
    this.Data["Username"] = sess_username
}