cisco anyconnect golang otp autologin

main.go

package main

import (
	"fmt"
	"os"
	"os/exec"
	"time"

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

const (
	otpSecret    = "secret_param_from_otp_url"
	user     = "login"
	password = "password"
	vpnHost      = "connect vpn.host.example"
	vpnBin       = "/opt/cisco/anyconnect/bin/vpn"
)

func main() {
	code, err := totp.GenerateCodeCustom(otpSecret, time.Now(), totp.ValidateOpts{
		Digits:    otp.DigitsSix,
		Algorithm: otp.AlgorithmSHA1,
		Period:    30,
	})
	if err != nil {
		panic(err)
	}
	cmd := exec.Command(vpnBin, "-s")
	stdin, err := cmd.StdinPipe()
	if err != nil {
		panic(err)
	}
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	go func() {
		defer stdin.Close()
		_, _ = fmt.Fprintln(stdin, vpnHost)
		_, _ = fmt.Fprintln(stdin, user)
		_, _ = fmt.Fprintln(stdin, password)
		_, _ = fmt.Fprintln(stdin, code)
	}()

	if err := cmd.Run(); err != nil {
		panic(err)
	}
}