Sample using duo security sms verify api with go

gistfile1.go

package main

import (
	"bytes"
	"crypto/hmac"
	"crypto/sha1"
	"crypto/tls"
	"encoding/base64"
	"encoding/hex"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"mime/multipart"
	"net/http"
	"net/url"
	"strings"
)

var (
	// Define these based on your integration settings
	host = "HOST"
	skey = []byte(`SKEY`)
	ikey = "IKEY"
	// Enter your phone number
	phone = "46702XXXXXX"
)

func request(uri string, params map[string]string) ([]byte, error) {
	duoUrl := "https://" + host + uri

	buf := new(bytes.Buffer)
	w := multipart.NewWriter(buf)
	if err := w.WriteField("phone", params["phone"]); err != nil {
		return nil, err
	}
	if err := w.WriteField("message", params["message"]); err != nil {
		return nil, err
	}
	w.Close()

	values := make(url.Values)
	values.Set("phone", params["phone"])
	values.Set("message", params["message"])

	sig := sign_request(uri, values.Encode())

	client := &http.Client{}
	req, err := http.NewRequest("POST", duoUrl, buf)
	req.Header.Add("Authorization", sig)
	req.Header.Set("Content-Type", w.FormDataContentType())
	resp, err := client.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()
	contents, err := ioutil.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}
	return contents, nil
}

func sign_request(uri, paramString string) string {
	canon := canon(uri, paramString)
	mac := hmac.New(sha1.New, skey)
	mac.Write(canon)
	md := mac.Sum(nil)
	data := ikey + ":" + hex.EncodeToString(md)
	b64 := base64.StdEncoding.EncodeToString([]byte(data))
	return "Basic " + b64
}

func canon(path, paramString string) []byte {
	paramString = strings.Replace(paramString, "+", "%20", -1)
	canon := fmt.Sprintf(`POST
%s
%s
%s`, host, path, paramString)

	return []byte(canon)
}

func main() {
	message := "Din engångskod för XYZ.se: <pin>"
	//message := "Your code: <pin>"

	params := map[string]string{"message": message,
		"phone": "+" + phone}

	fmt.Println("Attempting to sms: " + params["phone"])

	result, err := request("/verify/v1/sms.json", params)
	if err != nil {
		fmt.Println(err)
		return
	}

	type Response struct {
		Pin string
	}
	type DuoResponse struct {
		Stat           string
		Code           int
		Message        string
		Message_detail string
		Response       Response
	}
	var smsResponse DuoResponse
	err = json.Unmarshal(result, &smsResponse)

	if smsResponse.Stat != "OK" {
		fmt.Println("There was an error with the request:", smsResponse.Message)
		return
	}

	fmt.Print("Please enter the pin:")
	var inputPin string
	fmt.Scanln(&inputPin)

	if inputPin == smsResponse.Response.Pin {
		fmt.Println("Pin is correct")
	} else {
		fmt.Println("Pin is incorrect")
	}
}