lego/challenge/tlsalpn01/tls_alpn_challenge_server.go
2019-11-05 17:58:30 +01:00

95 lines
2.7 KiB
Go

package tlsalpn01
import (
"crypto/tls"
"fmt"
"net"
"net/http"
"strings"
"github.com/go-acme/lego/v3/log"
)
const (
// ACMETLS1Protocol is the ALPN Protocol ID for the ACME-TLS/1 Protocol.
ACMETLS1Protocol = "acme-tls/1"
// defaultTLSPort is the port that the ProviderServer will default to
// when no other port is provided.
defaultTLSPort = "443"
)
// ProviderServer implements ChallengeProvider for `TLS-ALPN-01` challenge.
// It may be instantiated without using the NewProviderServer
// if you want only to use the default values.
type ProviderServer struct {
iface string
port string
listener net.Listener
}
// NewProviderServer creates a new ProviderServer on the selected interface and port.
// Setting iface and / or port to an empty string will make the server fall back to
// the "any" interface and port 443 respectively.
func NewProviderServer(iface, port string) *ProviderServer {
return &ProviderServer{iface: iface, port: port}
}
func (s *ProviderServer) GetAddress() string {
return net.JoinHostPort(s.iface, s.port)
}
// Present generates a certificate with a SHA-256 digest of the keyAuth provided
// as the acmeValidation-v1 extension value to conform to the ACME-TLS-ALPN spec.
func (s *ProviderServer) Present(domain, token, keyAuth string) error {
if s.port == "" {
// Fallback to port 443 if the port was not provided.
s.port = defaultTLSPort
}
// Generate the challenge certificate using the provided keyAuth and domain.
cert, err := ChallengeCert(domain, keyAuth)
if err != nil {
return err
}
// Place the generated certificate with the extension into the TLS config
// so that it can serve the correct details.
tlsConf := new(tls.Config)
tlsConf.Certificates = []tls.Certificate{*cert}
// We must set that the `acme-tls/1` application level protocol is supported
// so that the protocol negotiation can succeed. Reference:
// https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-07#section-6.2
tlsConf.NextProtos = []string{ACMETLS1Protocol}
// Create the listener with the created tls.Config.
s.listener, err = tls.Listen("tcp", s.GetAddress(), tlsConf)
if err != nil {
return fmt.Errorf("could not start HTTPS server for challenge -> %v", err)
}
// Shut the server down when we're finished.
go func() {
err := http.Serve(s.listener, nil)
if err != nil && !strings.Contains(err.Error(), "use of closed network connection") {
log.Println(err)
}
}()
return nil
}
// CleanUp closes the HTTPS server.
func (s *ProviderServer) CleanUp(domain, token, keyAuth string) error {
if s.listener == nil {
return nil
}
// Server was created, close it.
if err := s.listener.Close(); err != nil && err != http.ErrServerClosed {
return err
}
return nil
}