GOLANG: latihan captcha pakai library https://github.com/mojocn/base64Captcha

cobaCaptcha.go

package main

import (
	"net/http"

	"github.com/julienschmidt/httprouter"
	"github.com/mojocn/base64Captcha"
)

func main() {
	r := httprouter.New()
	r.GET("/captcha", func(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
		//create a captchaInterface instance.
		//GenerateCaptcha first parameter is empty string,so the package will generate a random uuid for you.
		idkey, captchaInterfaceIntance := base64Captcha.GenerateCaptcha("", base64Captcha.ConfigCharacter{
			Height: 60,
			Width:  180,
			//const CaptchaModeNumber:数字,CaptchaModeAlphabet:字母,CaptchaModeArithmetic:算术,CaptchaModeNumberAlphabet:数字字母混合.
			Mode:               base64Captcha.CaptchaModeNumberAlphabet,
			ComplexOfNoiseText: base64Captcha.CaptchaComplexLower,
			ComplexOfNoiseDot:  base64Captcha.CaptchaComplexLower,
			IsUseSimpleFont:    false,
			IsShowHollowLine:   false,
			IsShowNoiseDot:     true,
			IsShowNoiseText:    false,
			IsShowSlimeLine:    false,
			IsShowSineLine:     false,
			CaptchaLen:         6,
		})
		http.SetCookie(w, &http.Cookie{
			Name:     "idkey",
			Value:    idkey,
			HttpOnly: true,
		})
		captchaInterfaceIntance.WriteTo(w)
	})
	r.POST("/captcha", func(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
		idkey, _ := r.Cookie("idkey")
		if base64Captcha.VerifyCaptcha(idkey.Value, r.PostFormValue("captcha")) {
			w.Write([]byte("verify OK"))
		} else {
			w.Write([]byte("verify false"))
		}
	})
	r.GET("/", func(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
		w.WriteHeader(200)
		w.Write([]byte(`
<iframe src="/captcha" name="captcha"></iframe><br>
<a href="/captcha" target="captcha">coba gambar lain</a><br>
<form method="POST" action="/captcha" target="hasil">
ketikkan teks di atas: <input name="captcha"><br>
<input type="submit" value="kirim">
</form>
<iframe src="about:blank" name="hasil"></iframe>
		`))
	})
	http.ListenAndServe(":8080", r)
}

screenshot.md