batazor/go-auth

package recaptcha

import (
    "encoding/json"
    "errors"
    "github.com/micro-company/go-auth/utils"
    "io/ioutil"
    "net/http"
    "net/url"
    "strings"
)

var (
    RECAPTCHA_PRIVATE_KEY string
)

const recaptchaServerName = "https://www.google.com/recaptcha/api/siteverify"

func init() {
    // Get configuration
    RECAPTCHA_PRIVATE_KEY = utils.Getenv("RECAPTCHA_PRIVATE_KEY", "localhost/auth")
}

func VerifyCaptcha(captchaResponse []byte) error {
    var captcha Captcha
    err := json.Unmarshal(captchaResponse, &captcha)
    if err != nil {
        return err
    }

    r, err := http.PostForm(recaptchaServerName,
        url.Values{"secret": {RECAPTCHA_PRIVATE_KEY}, "response": {captcha.Captcha}})
    if err != nil {
        return err
    }

    b, err := ioutil.ReadAll(r.Body)
    defer r.Body.Close()
    if err != nil {
        return errors.New(`"` + err.Error() + `"`)
    }

    var recaptcha RecaptchaResponse
    err = json.Unmarshal(b, &recaptcha)
    if err != nil {
        return errors.New(`"` + err.Error() + `"`)
    }

    if recaptcha.Success {
        return nil
    }

    return errors.New(`"` + strings.Join(recaptcha.ErrorCodes[:], ",") + `"`)
}