A Basic Go Webserver Using Lego listening on the ports 8443 and 8080.

webserver2.go

package main

import (
	"crypto"
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"fmt"
	"log"

	"github.com/xenolf/lego/certcrypto"
	"github.com/xenolf/lego/certificate"
	"github.com/xenolf/lego/challenge/http01"
	"github.com/xenolf/lego/challenge/tlsalpn01"
	"github.com/xenolf/lego/lego"
	"github.com/xenolf/lego/registration"
)

func main() {
	privateKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
	if err != nil {
		log.Fatal(err)
	}

	myUser := MyUser{
		Email: "[email protected]",
		key:   privateKey,
	}

	config := lego.NewConfig(&myUser)

	config.CADirURL = "https://acme-staging-v02.api.letsencrypt.org/directory"
	config.Certificate.KeyType = certcrypto.RSA2048

	client, err := lego.NewClient(config)
	if err != nil {
		log.Fatal(err)
	}

	err = client.Challenge.SetHTTP01Provider(http01.NewProviderServer("", "8080"))
	if err != nil {
		log.Fatal(err)
	}
	err = client.Challenge.SetTLSALPN01Provider(tlsalpn01.NewProviderServer("", "8443"))
	if err != nil {
		log.Fatal(err)
	}

	// New users will need to register
	reg, err := client.Registration.Register(registration.RegisterOptions{TermsOfServiceAgreed: true})
	if err != nil {
		log.Fatal(err)
	}
	myUser.Registration = reg

	request := certificate.ObtainRequest{
		Domains: []string{"example.com"},
		Bundle:  true,
	}
	certificates, err := client.Certificate.Obtain(request)
	if err != nil {
		log.Fatal(err)
	}

	// Each certificate comes back with the cert bytes, the bytes of the client's
	// private key, and a certificate URL. SAVE THESE TO DISK.
	fmt.Printf("%#v\n", certificates)
}

// You'll need a user or account type that implements acme.User
type MyUser struct {
	Email        string
	Registration *registration.Resource
	key          crypto.PrivateKey
}

func (u *MyUser) GetEmail() string {
	return u.Email
}
func (u MyUser) GetRegistration() *registration.Resource {
	return u.Registration
}
func (u *MyUser) GetPrivateKey() crypto.PrivateKey {
	return u.key
}