知识结构

1.gin
2.session中间件
3.表单处理
4.路由

下载包

go get github.com/dchest/captcha

配置session

func SessionConfig() sessions.Store {
	sessionMaxAge := 3600
	sessionSecret := "golang-tech-stack"
	store := cookie.NewStore([]byte(sessionSecret))
	store.Options(sessions.Options{
		MaxAge: sessionMaxAge, //seconds
		Path:   "/",
	})
	return store
}

中间件 处理session

// 中间件，处理session
func Session(keyPairs string) gin.HandlerFunc {
	store := SessionConfig()
	return sessions.Sessions(keyPairs, store)
}

生成图片

// 生成图片
func Serve(w http.ResponseWriter, r *http.Request, id, ext, lang string, download bool, width, height int) error {
	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
	w.Header().Set("Pragma", "no-cache")
	w.Header().Set("Expires", "0")

	var content bytes.Buffer
	switch ext {
	case ".png":
		w.Header().Set("Content-Type", "image/png")
		_ = captcha.WriteImage(&content, id, width, height)
	case ".wav":
		w.Header().Set("Content-Type", "audio/x-wav")
		_ = captcha.WriteAudio(&content, id, lang)
	default:
		return captcha.ErrNotFound
	}

	if download {
		w.Header().Set("Content-Type", "application/octet-stream")
	}
	http.ServeContent(w, r, id+ext, time.Time{}, bytes.NewReader(content.Bytes()))
	return nil
}
// 生成验证码
func Captcha(c *gin.Context, length ...int) {
	l := captcha.DefaultLen
	w, h := 107, 36
	if len(length) == 1 {
		l = length[0]
	}
	if len(length) == 2 {
		w = length[1]
	}
	if len(length) == 3 {
		h = length[2]
	}
	captchaId := captcha.NewLen(l)
	session := sessions.Default(c)
	session.Set("captcha", captchaId)
	_ = session.Save()
	_ = Serve(c.Writer, c.Request, captchaId, ".png", "zh", false, w, h)
}

验证

func CaptchaVerify(c *gin.Context, code string) bool {
	session := sessions.Default(c)
	if captchaId := session.Get("captcha"); captchaId != nil {
		session.Delete("captcha")
		_ = session.Save()
		if captcha.VerifyString(captchaId.(string), code) {
			return true
		} else {
			return false
		}
	} else {
		return false
	}
}

前端页面

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>验证码</title>
</head>
<body>


<h1>Golang 验证码</h1>

<form action="/captcha/verify/" method="post">

    User: <input type="text"> <br>
    Pwd: <input type="password"> <br>
    Captcha：<input type="text" name="code"> 

    <img src="/captcha" onclick="this.src='/captcha?v='+Math.random()">

    <input type="submit">
</form>
</body>
</html>

测试

// 测试
func main() {
	router := gin.Default()
	router.LoadHTMLGlob("./*.html")
	router.Use(Session("golang-tech-stack"))
	router.GET("/captcha", func(c *gin.Context) {
		Captcha(c, 4)
	})
	router.GET("/", func(c *gin.Context) {
		c.HTML(http.StatusOK, "index.html", nil)
	})
	router.POST("/captcha/verify/", func(c *gin.Context) {
		value := c.PostForm("code")
		if CaptchaVerify(c, value) {
			c.JSON(http.StatusOK, gin.H{"status": 0, "msg": "success"})
		} else {
			c.JSON(http.StatusOK, gin.H{"status": 1, "msg": "failed"})
		}
	})
	router.Run(":8080")

	// http://localhost:8080/

}