Go Script to read TOTP secrets from a file and generating auth codes

totp-reader.go

package main

import (
	"bufio"
	"fmt"
	"log"
	"net/url"
	"os"
	"strings"
	"time"

	"github.com/olekukonko/tablewriter"
	"github.com/pquerna/otp/totp"
)

type TOTPInfo struct {
	Secret  string
	Title   string
	Account string
}

func main() {
	file, err := os.Open("totp.keys")
	if err != nil {
		log.Fatalf("failed to open file: %v", err)
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	var totpInfos []TOTPInfo
	for scanner.Scan() {
		totpURL := scanner.Text()
		secret, title, account := extractSecretAndTitle(totpURL)
		if secret != "" && title != "" && account != "" {
			totpInfos = append(totpInfos, TOTPInfo{Secret: secret, Title: title, Account: account})
		}
	}
	if err := scanner.Err(); err != nil {
		log.Fatalf("error reading file: %v", err)
	}

	stopSpinner := make(chan bool)
	defer close(stopSpinner)

	go spinner(stopSpinner)

	ticker := time.NewTicker(5 * time.Second)
	defer ticker.Stop()

	for {
		select {
		case <-ticker.C:
			data := [][]string{}
			for _, info := range totpInfos {
				code, err := totp.GenerateCode(info.Secret, time.Now())
				if err != nil {
					log.Printf("failed to generate TOTP code for %s: %v", info.Title, err)
					continue
				}
				data = append(data, []string{info.Title, info.Account, code})
			}
			printTable(data)
		}
	}
}

func extractSecretAndTitle(totpURL string) (string, string, string) {
	u, err := url.Parse(totpURL)
	if err != nil {
		log.Printf("failed to parse TOTP URL: %v", err)
		return "", "", ""
	}

	secret := u.Query().Get("secret")
	if secret == "" {
		log.Printf("failed to find secret in TOTP URL")
		return "", "", ""
	}

	pathParts := strings.Split(u.Path, ":")
	if len(pathParts) < 2 {
		log.Printf("failed to find title in TOTP URL")
		return "", "", ""
	}
	title := pathParts[0]
	account := pathParts[1]

	return secret, title, account
}

func spinner(stop chan bool) {
	spinChars := []rune{'|', '/', '-', '\\'}
	i := 0
	for {
		select {
		case <-stop:
			return
		default:
			fmt.Printf("\r%c", spinChars[i])
			i = (i + 1) % len(spinChars)
			time.Sleep(100 * time.Millisecond)
		}
	}
}

func printTable(data [][]string) {
	fmt.Printf("\r")
	table := tablewriter.NewWriter(os.Stdout)
	table.SetHeader([]string{"APP Name", "Account", "TOTP Code"})
	for _, v := range data {
		table.Append(v)
	}
	table.Render()
}

create totp.keys file with a format like this (the totp standard URL format) next to the project binary or source code:

otpauth://totp/reza%20app:user%40email.com?secret=5X5F4LZHKVBGRISXLVBEK7K4TU&issuer=reza%20app 
otpauth://totp/reza%20app:user%40somehow.com?secret=5X5F4LZHKVBGRISXLVBEK7K4TU&issuer=reza%20app 

build and run project:

go build
./totp-reader

Output: