// idea by 'github.com/graetzer/go-recaptcha' with optomize, but might not fit for everyone

go-recaptcha.go

/* -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.

* File Name : recaptcha.go

* Purpose :

* Creation Date : 03-22-2015

* Last Modified : Sun 22 Mar 2015 09:43:16 PM PDT

* Created By : Kiyor

_._._._._._._._._._._._._._._._._._._._._.*/

// idea by 'github.com/graetzer/go-recaptcha'
// with optomize, but might not fit for everyone

package recaptcha

import (
	"encoding/json"
	"errors"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
)

// https://www.google.com/recaptcha/api/siteverify?secret=your_secret&response=response_string&remoteip=user_ip_address
const recaptcha_url = "https://www.google.com/recaptcha/api/siteverify?"

var recaptcha_secret string

// check uses the client ip address and the client's response input to determine whether or not
// the client answered the reCaptcha input question correctly.
// It returns a boolean value indicating whether or not the client answered correctly.
func check(args ...string) (body []byte, err error) {
	response := args[0]
	vals := url.Values{"secret": {recaptcha_secret}, "response": {response}}
	if len(args) > 1 {
		remoteip := args[1]
		vals["remoteip"] = []string{remoteip}
	}
	resp, err := http.Get(recaptcha_url + vals.Encode())
	if err != nil {
		return
	}
	defer resp.Body.Close()
	body, err = ioutil.ReadAll(resp.Body)
	if err != nil {
		return
	}
	return
}

// Confirm is the public interface function.
// It calls check, which the client ip address, the challenge code from the reCaptcha form,
// and the client's response input to that challenge to determine whether or not
// the client answered the reCaptcha input question correctly.
// It returns a boolean value indicating whether or not the client answered correctly.
func Confirm(args ...string) (bool, error) {
	var v map[string]interface{}
	var body []byte
	var err error
	switch len(args) {
	case 1:
		body, err = check(args[0])
	case 2:
		body, err = check(args[0], args[1])
	default:
		return false, errors.New("args should be response, remoteip(Optional)")
	}
	if err != nil {
		return false, err
	}
	if err := json.Unmarshal(body, &v); err != nil {
		return false, err
	}
	if e, found := v["error-codes"]; found {
		return false, errors.New(fmt.Sprint(e))
	}
	success, ok := v["success"].(bool)
	return ok && success, nil
}

// Init allows the webserver or code evaluating the reCaptcha form input to set the
// reCaptcha secret (string) value.
func Init(secret string) {
	recaptcha_secret = secret
}