Golang图形验证码支持高度定制

Java基础

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2020-6-16

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Base64captcha 项目地址

几行代码就可以定义自己内容的图形验证码库,支持任意unicode字符的内容.

1. 文档&Demo

2. 快速上手

2.1 下载base64Captcha包

go get -u github.com/mojocn/base64Captcha

2.2 在你的项目中使用base64Captcha

2.2.1 实现Store interface 或者使用自带memory store

type Store interface {
    // Set sets the digits for the captcha id.
    Set(id string, value string)

    // Get returns stored digits for the captcha id. Clear indicates
    // whether the captcha must be deleted from the store.
    Get(id string, clear bool) string
    
    //Verify captcha's answer directly
    Verify(id, answer string, clear bool) bool
}

2.2.2 实现Driver interface 或者使用自带 drivers

包自带driver:

  1. Driver Digit
  2. Driver String
  3. Driver Math
  4. Driver Chinese
// Driver captcha interface for captcha engine to to write staff
type Driver interface {
    //DrawCaptcha draws binary item
    DrawCaptcha(content string) (item Item, err error)
    //GenerateIdQuestionAnswer creates rand id, content and answer
    GenerateIdQuestionAnswer() (id, q, a string)
}

2.2.3 核心代码captcha.go

captcha.go 是package的入口文件,源代码逻辑非常简单,如下:

func init() {
    //init rand seed
    rand.Seed(time.Now().UnixNano())
}

// Captcha captcha basic information.
type Captcha struct {
    Driver Driver
    Store  Store
}

func NewCaptcha(driver Driver, store Store) *Captcha {
    return &Captcha{Driver: driver, Store: store}
}

//Generate generates a random id, base64 image string or an error if any
func (c *Captcha) Generate() (id, b64s string, err error) {
    id,content, answer := c.Driver.GenerateIdQuestionAnswer()
    item, err := c.Driver.DrawCaptcha(content)
    if err != nil {
        return "", "", err
    }
    c.Store.Set(id, answer)
    b64s = item.EncodeB64string()
    return
}
//if you has multiple captcha instances which shares a same store. You may want to use `store.Verify` method instead.
//Verify by given id key and remove the captcha value in store, return boolean value.
func (c *Captcha) Verify(id, answer string, clear bool) (match bool) {
    match = c.Store.Get(id, clear) == answer
    return
}

2.2.4 生成Base64(image/audio)验证码字符串

//Generate generates a random id, base64 image string or an error if any
func (c *Captcha) Generate() (id, b64s string, err error) {
    id,content, answer := c.Driver.GenerateIdQuestionAnswer()
    item, err := c.Driver.DrawCaptcha(content)
    if err != nil {
        return "", "", err
    }
    c.Store.Set(id, answer)
    b64s = item.EncodeB64string()
    return
}

2.2.5 🤸 校验验证码内容 🤸

//if you has multiple captcha instances which shares a same store. You may want to use `store.Verify` method instead.
//Verify by given id key and remove the captcha value in store, return boolean value.
func (c *Captcha) Verify(id, answer string, clear bool) (match bool) {
    match = c.Store.Get(id, clear) == answer
    return
}

2.2.6 完整实例代码

// example of HTTP server that uses the captcha package.
package main

import (
    "encoding/json"
    "fmt"
    "github.com/mojocn/base64Captcha"
    "log"
    "net/http"
)

//configJsonBody json request body.
type configJsonBody struct {
    Id            string
    CaptchaType   string
    VerifyValue   string
    DriverAudio   *base64Captcha.DriverAudio
    DriverString  *base64Captcha.DriverString
    DriverChinese *base64Captcha.DriverChinese
    DriverMath    *base64Captcha.DriverMath
    DriverDigit   *base64Captcha.DriverDigit
}

var store = base64Captcha.DefaultMemStore

// base64Captcha create http handler
func generateCaptchaHandler(w http.ResponseWriter, r *http.Request) {
    //parse request parameters
    decoder := json.NewDecoder(r.Body)
    var param configJsonBody
    err := decoder.Decode(&param)
    if err != nil {
        log.Println(err)
    }
    defer r.Body.Close()
    var driver base64Captcha.Driver

    //create base64 encoding captcha
    switch param.CaptchaType {
    case "audio":
        driver = param.DriverAudio
    case "string":
        driver = param.DriverString.ConvertFonts()
    case "math":
        driver = param.DriverMath.ConvertFonts()
    case "chinese":
        driver = param.DriverChinese.ConvertFonts()
    default:
        driver = param.DriverDigit
    }
    c := base64Captcha.NewCaptcha(driver, store)
    id, b64s, err := c.Generate()
    body := map[string]interface{}{"code": 1, "data": b64s, "captchaId": id, "msg": "success"}
    if err != nil {
        body = map[string]interface{}{"code": 0, "msg": err.Error()}
    }
    w.Header().Set("Content-Type", "application/json; charset=utf-8")
    json.NewEncoder(w).Encode(body)
}

// base64Captcha verify http handler
func captchaVerifyHandle(w http.ResponseWriter, r *http.Request) {

    //parse request json body
    decoder := json.NewDecoder(r.Body)
    var param configJsonBody
    err := decoder.Decode(&param)
    if err != nil {
        log.Println(err)
    }
    defer r.Body.Close()
    //verify the captcha
    body := map[string]interface{}{"code": 0, "msg": "failed"}
    if store.Verify(param.Id, param.VerifyValue, true) {
        body = map[string]interface{}{"code": 1, "msg": "ok"}
    }
    //set json response
    w.Header().Set("Content-Type", "application/json; charset=utf-8")

    json.NewEncoder(w).Encode(body)
}

//start a net/http server
func main() {
    //serve Vuejs+ElementUI+Axios Web Application
    http.Handle("/", http.FileServer(http.Dir("./static")))

    //api for create captcha
    http.HandleFunc("/api/getCaptcha", generateCaptchaHandler)

    //api for verify captcha
    http.HandleFunc("/api/verifyCaptcha", captchaVerifyHandle)

    fmt.Println("Server is at :8777")
    if err := http.ListenAndServe(":8777", nil); err != nil {
        log.Fatal(err)
    }
}

2.3  使用历史版本 

v1.2.2

go get github.com/mojocn/base64Captcha@v1.2.2

3. 定制自己的图形验证码

你那个定制自己的图形验码内容,只需实现 interface driverinterface item.

下面是几个可以参考的driver实现示例:

  1. DriverMath
  2. DriverChinese
  3. ItemChar

你甚至可以设计captcha struct成你想要的功能

4. 致谢

5. Licence

base64Captcha source code is licensed under the Apache Licence, Version 2.0
(http://www.apache.org/license…

作者:TechMojotv