tls: Add support for the tls-alpn-01 challenge (#2201)

* tls: Add support for the tls-alpn-01 challenge

Also updates lego/acme to latest on master.

TODO: This implementation of the tls-alpn challenge is not yet solvable
in a distributed Caddy cluster like the http challenge is.

* build: Allow building with the race detector

* tls: Support distributed solving of the TLS-ALPN-01 challenge

* Update vendor and add a todo in MITM checker

caddy/build.go

@@ -42,11 +42,13 @@ import (
 )
 
 var goos, goarch, goarm string
+var race bool
 
 func init() {
 	flag.StringVar(&goos, "goos", "", "GOOS for which to build")
 	flag.StringVar(&goarch, "goarch", "", "GOARCH for which to build")
 	flag.StringVar(&goarm, "goarm", "", "GOARM for which to build")
+	flag.BoolVar(&race, "race", false, "Enable race detector")
 }
 
 func main() {
@@ -67,6 +69,9 @@ func main() {
 	args := []string{"build", "-ldflags", ldflags}
 	args = append(args, "-asmflags", fmt.Sprintf("-trimpath=%s", gopath))
 	args = append(args, "-gcflags", fmt.Sprintf("-trimpath=%s", gopath))
+	if race {
+		args = append(args, "-race")
+	}
 	cmd := exec.Command("go", args...)
 	cmd.Stderr = os.Stderr
 	cmd.Stdout = os.Stdout
@@ -77,6 +82,9 @@ func main() {
 		"GOARCH=" + goarch,
 		"GOARM=" + goarm,
 	} {
+		if race && env == "CGO_ENABLED=0" {
+			continue
+		}
 		cmd.Env = append(cmd.Env, env)
 	}
 

caddy/caddymain/run.go

@@ -33,7 +33,7 @@ import (
 	"github.com/mholt/caddy"
 	"github.com/mholt/caddy/caddytls"
 	"github.com/mholt/caddy/telemetry"
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 	"gopkg.in/natefinch/lumberjack.v2"
 
 	_ "github.com/mholt/caddy/caddyhttp" // plug in the HTTP server type
@@ -47,7 +47,7 @@ func init() {
 	flag.BoolVar(&caddytls.Agreed, "agree", false, "Agree to the CA's Subscriber Agreement")
 	flag.StringVar(&caddytls.DefaultCAUrl, "ca", "https://acme-v02.api.letsencrypt.org/directory", "URL to certificate authority's ACME server directory")
 	flag.BoolVar(&caddytls.DisableHTTPChallenge, "disable-http-challenge", caddytls.DisableHTTPChallenge, "Disable the ACME HTTP challenge")
-	flag.BoolVar(&caddytls.DisableTLSSNIChallenge, "disable-tls-sni-challenge", caddytls.DisableTLSSNIChallenge, "Disable the ACME TLS-SNI challenge")
+	flag.BoolVar(&caddytls.DisableTLSALPNChallenge, "disable-tls-alpn-challenge", caddytls.DisableTLSALPNChallenge, "Disable the ACME TLS-ALPN challenge")
 	flag.StringVar(&disabledMetrics, "disabled-metrics", "", "Comma-separated list of telemetry metrics to disable")
 	flag.StringVar(&conf, "conf", "", "Caddyfile to load (default \""+caddy.DefaultConfigFile+"\")")
 	flag.StringVar(&cpu, "cpu", "100%", "CPU cap")

caddyhttp/httpserver/https.go

@@ -207,7 +207,7 @@ func redirPlaintextHost(cfg *SiteConfig) *SiteConfig {
 		Addr:       Address{Original: addr, Host: host, Port: port},
 		ListenHost: cfg.ListenHost,
 		middleware: []Middleware{redirMiddleware},
-		TLS:        &caddytls.Config{AltHTTPPort: cfg.TLS.AltHTTPPort, AltTLSSNIPort: cfg.TLS.AltTLSSNIPort},
+		TLS:        &caddytls.Config{AltHTTPPort: cfg.TLS.AltHTTPPort, AltTLSALPNPort: cfg.TLS.AltTLSALPNPort},
 		Timeouts:   cfg.Timeouts,
 	}
 }

caddyhttp/httpserver/mitm.go

@@ -74,6 +74,7 @@ func (h *tlsHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	if r.Header.Get("X-BlueCoat-Via") != "" || // Blue Coat (masks User-Agent header to generic values)
 		r.Header.Get("X-FCCKV2") != "" || // Fortinet
 		info.advertisesHeartbeatSupport() { // no major browsers have ever implemented Heartbeat
+		// TODO: Move the heartbeat check into each "looksLike" function...
 		checked = true
 		mitm = true
 	} else if strings.Contains(ua, "Edge") || strings.Contains(ua, "MSIE") ||

caddyhttp/httpserver/plugin.go

@@ -169,12 +169,12 @@ func (h *httpContext) InspectServerBlocks(sourceFile string, serverBlocks []cadd
 
 			// If default HTTP or HTTPS ports have been customized,
 			// make sure the ACME challenge ports match
-			var altHTTPPort, altTLSSNIPort string
+			var altHTTPPort, altTLSALPNPort string
 			if HTTPPort != DefaultHTTPPort {
 				altHTTPPort = HTTPPort
 			}
 			if HTTPSPort != DefaultHTTPSPort {
-				altTLSSNIPort = HTTPSPort
+				altTLSALPNPort = HTTPSPort
 			}
 
 			// Make our caddytls.Config, which has a pointer to the
@@ -183,7 +183,7 @@ func (h *httpContext) InspectServerBlocks(sourceFile string, serverBlocks []cadd
 			caddytlsConfig := caddytls.NewConfig(h.instance)
 			caddytlsConfig.Hostname = addr.Host
 			caddytlsConfig.AltHTTPPort = altHTTPPort
-			caddytlsConfig.AltTLSSNIPort = altTLSSNIPort
+			caddytlsConfig.AltTLSALPNPort = altTLSALPNPort
 
 			// Save the config to our master list, and key it for lookups
 			cfg := &SiteConfig{

caddytls/client.go

@@ -27,7 +27,7 @@ import (
 
 	"github.com/mholt/caddy"
 	"github.com/mholt/caddy/telemetry"
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 // acmeMu ensures that only one ACME challenge occurs at a time.
@@ -121,68 +121,69 @@ var newACMEClient = func(config *Config, allowPrompts bool) (*ACMEClient, error)
 	}
 
 	if config.DNSProvider == "" {
-		// Use HTTP and TLS-SNI challenges by default
+		// Use HTTP and TLS-ALPN challenges by default
 
-		// See if HTTP challenge needs to be proxied
+		// figure out which ports we'll be serving the challenges on
 		useHTTPPort := HTTPChallengePort
+		useTLSALPNPort := TLSALPNChallengePort
 		if config.AltHTTPPort != "" {
 			useHTTPPort = config.AltHTTPPort
 		}
+		if config.AltTLSALPNPort != "" {
+			useTLSALPNPort = config.AltTLSALPNPort
+		}
 		if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, useHTTPPort)) {
 			useHTTPPort = DefaultHTTPAlternatePort
 		}
 
-		// TODO: tls-sni challenge was removed in January 2018, but a variant of it might return
-		// See which port TLS-SNI challenges will be accomplished on
-		// useTLSSNIPort := TLSSNIChallengePort
-		// if config.AltTLSSNIPort != "" {
-		// 	useTLSSNIPort = config.AltTLSSNIPort
-		// }
-		// err := c.acmeClient.SetTLSAddress(net.JoinHostPort(config.ListenHost, useTLSSNIPort))
-		// if err != nil {
-		// 	return nil, err
-		// }
-
-		// if using file storage, we can distribute the HTTP challenge across
-		// all instances sharing the acme folder; either way, we must still set
-		// the address for the default HTTP provider server
-		var useDistributedHTTPSolver bool
+		// if using file storage, we can distribute the HTTP or TLS-ALPN challenge
+		// across all instances sharing the acme folder; either way, we must still
+		// set the address for the default provider server
+		var useDistributedSolver bool
 		if storage, err := c.config.StorageFor(c.config.CAUrl); err == nil {
 			if _, ok := storage.(*FileStorage); ok {
-				useDistributedHTTPSolver = true
+				useDistributedSolver = true
 			}
 		}
-		if useDistributedHTTPSolver {
-			c.acmeClient.SetChallengeProvider(acme.HTTP01, distributedHTTPSolver{
-				// being careful to respect user's listener bind preferences
-				httpProviderServer: acme.NewHTTPProviderServer(config.ListenHost, useHTTPPort),
+		if useDistributedSolver {
+			// ... being careful to respect user's listener bind preferences
+			c.acmeClient.SetChallengeProvider(acme.HTTP01, distributedSolver{
+				providerServer: acme.NewHTTPProviderServer(config.ListenHost, useHTTPPort),
+			})
+			c.acmeClient.SetChallengeProvider(acme.TLSALPN01, distributedSolver{
+				providerServer: acme.NewTLSALPNProviderServer(config.ListenHost, useTLSALPNPort),
 			})
 		} else {
 			// Always respect user's bind preferences by using config.ListenHost.
-			// NOTE(Sep'16): At time of writing, SetHTTPAddress() and SetTLSAddress()
-			// must be called before SetChallengeProvider() (see above), since they reset
-			// the challenge provider back to the default one! (still true in March 2018)
+			// NOTE(Nov'18): At time of writing, SetHTTPAddress() and SetTLSAddress()
+			// reset the challenge provider back to the default one, overriding
+			// anything set by SetChalllengeProvider(). Calling them mutually
+			// excuslively is safe, as is calling Set*Address() before SetChallengeProvider().
 			err := c.acmeClient.SetHTTPAddress(net.JoinHostPort(config.ListenHost, useHTTPPort))
 			if err != nil {
 				return nil, err
 			}
+			err = c.acmeClient.SetTLSAddress(net.JoinHostPort(config.ListenHost, useTLSALPNPort))
+			if err != nil {
+				return nil, err
+			}
 		}
 
-		// TODO: tls-sni challenge was removed in January 2018, but a variant of it might return
-		// See if TLS challenge needs to be handled by our own facilities
-		// if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, useTLSSNIPort)) {
-		// 	c.acmeClient.SetChallengeProvider(acme.TLSSNI01, tlsSNISolver{certCache: config.certCache})
-		// }
+		// if this server is already listening on the TLS-ALPN port we're supposed to use,
+		// then wire up this config's ACME client to use our own facilities for solving
+		// the challenge: our own certificate cache, since we already have a listener
+		if caddy.HasListenerWithAddress(net.JoinHostPort(config.ListenHost, useTLSALPNPort)) {
+			c.acmeClient.SetChallengeProvider(acme.TLSALPN01, tlsALPNSolver{certCache: config.certCache})
+		}
 
 		// Disable any challenges that should not be used
 		var disabledChallenges []acme.Challenge
 		if DisableHTTPChallenge {
 			disabledChallenges = append(disabledChallenges, acme.HTTP01)
 		}
-		// TODO: tls-sni challenge was removed in January 2018, but a variant of it might return
-		// if DisableTLSSNIChallenge {
-		// 	disabledChallenges = append(disabledChallenges, acme.TLSSNI01)
-		// }
+		if DisableTLSALPNChallenge {
+			disabledChallenges = append(disabledChallenges, acme.TLSALPN01)
+		}
 		if len(disabledChallenges) > 0 {
 			c.acmeClient.ExcludeChallenges(disabledChallenges)
 		}
@@ -203,9 +204,7 @@ var newACMEClient = func(config *Config, allowPrompts bool) (*ACMEClient, error)
 		}
 
 		// Use the DNS challenge exclusively
-		// TODO: tls-sni challenge was removed in January 2018, but a variant of it might return
-		// c.acmeClient.ExcludeChallenges([]acme.Challenge{acme.HTTP01, acme.TLSSNI01})
-		c.acmeClient.ExcludeChallenges([]acme.Challenge{acme.HTTP01})
+		c.acmeClient.ExcludeChallenges([]acme.Challenge{acme.HTTP01, acme.TLSALPN01})
 		c.acmeClient.SetChallengeProvider(acme.DNS01, prov)
 	}
 
@@ -312,7 +311,7 @@ func (c *ACMEClient) Renew(name string) error {
 	certMeta.PrivateKey = siteData.Key
 
 	// Perform renewal and retry if necessary, but not too many times.
-	var newCertMeta acme.CertificateResource
+	var newCertMeta *acme.CertificateResource
 	var success bool
 	for attempts := 0; attempts < 2; attempts++ {
 		namesObtaining.Add([]string{name})
@@ -321,10 +320,8 @@ func (c *ACMEClient) Renew(name string) error {
 		acmeMu.Unlock()
 		namesObtaining.Remove([]string{name})
 		if err == nil {
-			// double-check that we actually got a certificate; check a couple fields
-			// TODO: This is a temporary workaround for what I think is a bug in the acmev2 package (March 2018)
-			// but it might not hurt to keep this extra check in place
-			if newCertMeta.Domain == "" || newCertMeta.Certificate == nil {
+			// double-check that we actually got a certificate; check a couple fields, just in case
+			if newCertMeta == nil || newCertMeta.Domain == "" || newCertMeta.Certificate == nil {
 				err = errors.New("returned certificate was empty; probably an unchecked error renewing it")
 			} else {
 				success = true

caddytls/config.go

@@ -26,7 +26,7 @@ import (
 
 	"github.com/klauspost/cpuid"
 	"github.com/mholt/caddy"
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 // Config describes how TLS should be configured and used.
@@ -102,10 +102,10 @@ type Config struct {
 	AltHTTPPort string
 
 	// The alternate port (ONLY port, not host)
-	// to use for the ACME TLS-SNI challenge.
-	// The system must forward TLSSNIChallengePort
+	// to use for the ACME TLS-ALPN challenge;
+	// the system must forward TLSALPNChallengePort
 	// to this port for challenge to succeed
-	AltTLSSNIPort string
+	AltTLSALPNPort string
 
 	// The string identifier of the DNS provider
 	// to use when solving the ACME DNS challenge
@@ -343,6 +343,18 @@ func (c *Config) buildStandardTLSConfig() error {
 		}
 	}
 
+	// ensure ALPN includes the ACME TLS-ALPN protocol
+	var alpnFound bool
+	for _, a := range c.ALPN {
+		if a == acme.ACMETLS1Protocol {
+			alpnFound = true
+			break
+		}
+	}
+	if !alpnFound {
+		c.ALPN = append(c.ALPN, acme.ACMETLS1Protocol)
+	}
+
 	config.MinVersion = c.ProtocolMinVersion
 	config.MaxVersion = c.ProtocolMaxVersion
 	config.ClientAuth = c.ClientAuth
@@ -695,13 +707,13 @@ var defaultCurves = []tls.CurveID{
 }
 
 const (
-	// HTTPChallengePort is the officially designated port for
+	// HTTPChallengePort is the officially-designated port for
 	// the HTTP challenge according to the ACME spec.
 	HTTPChallengePort = "80"
 
-	// TLSSNIChallengePort is the officially designated port for
-	// the TLS-SNI challenge according to the ACME spec.
-	TLSSNIChallengePort = "443"
+	// TLSALPNChallengePort is the officially-designated port for
+	// the TLS-ALPN challenge according to the ACME spec.
+	TLSALPNChallengePort = "443"
 
 	// DefaultHTTPAlternatePort is the port on which the ACME
 	// client will open a listener and solve the HTTP challenge.

caddytls/crypto.go

@@ -42,7 +42,7 @@ import (
 	"golang.org/x/crypto/ocsp"
 
 	"github.com/mholt/caddy"
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 // loadPrivateKey loads a PEM-encoded ECC/RSA private key from an array of bytes.

caddytls/filestorage.go

@@ -281,11 +281,13 @@ func (s *FileStorage) MostRecentUserEmail() string {
 func fileSafe(str string) string {
 	str = strings.ToLower(str)
 	str = strings.TrimSpace(str)
-	repl := strings.NewReplacer("..", "",
+	repl := strings.NewReplacer(
+		"..", "",
 		"/", "",
 		"\\", "",
 		// TODO: Consider also replacing "@" with "_at_" (but migrate existing accounts...)
 		"+", "_plus_",
+		"*", "wildcard_",
 		"%", "",
 		"$", "",
 		"`", "",
@@ -297,8 +299,7 @@ func fileSafe(str string) string {
 		"#", "",
 		"&", "",
 		"|", "",
-		"\"", "",
-		"'", "",
-		"*", "wildcard_")
+		`"`, "",
+		"'", "")
 	return repl.Replace(str)
 }

caddytls/handshake.go

@@ -16,17 +16,20 @@ package caddytls
 
 import (
 	"crypto/tls"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"log"
 	"net/http"
 	"net/url"
+	"os"
 	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
 
 	"github.com/mholt/caddy/telemetry"
+	"github.com/xenolf/lego/acme"
 )
 
 // configGroup is a type that keys configs by their hostname
@@ -111,6 +114,32 @@ func (cfg *Config) GetCertificate(clientHello *tls.ClientHelloInfo) (*tls.Certif
 		go telemetry.SetNested("tls_client_hello", info.Key(), info)
 	}
 
+	// special case: serve up the certificate for a TLS-ALPN ACME challenge
+	// (https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-05)
+	for _, proto := range clientHello.SupportedProtos {
+		if proto == acme.ACMETLS1Protocol {
+			cfg.certCache.RLock()
+			challengeCert, ok := cfg.certCache.cache[tlsALPNCertKeyName(clientHello.ServerName)]
+			cfg.certCache.RUnlock()
+			if !ok {
+				// see if this challenge was started in a cluster; try distributed challenge solver
+				// (note that the tls.Config's ALPN settings must include the ACME TLS-ALPN challenge
+				// protocol string, otherwise a valid certificate will not solve the challenge; we
+				// should already have taken care of that when we made the tls.Config)
+				challengeCert, ok, err := cfg.tryDistributedChallengeSolver(clientHello)
+				if err != nil {
+					log.Printf("[ERROR][%s] TLS-ALPN: %v", clientHello.ServerName, err)
+				}
+				if ok {
+					return &challengeCert.Certificate, nil
+				}
+
+				return nil, fmt.Errorf("no certificate to complete TLS-ALPN challenge for SNI name: %s", clientHello.ServerName)
+			}
+			return &challengeCert.Certificate, nil
+		}
+	}
+
 	// get the certificate and serve it up
 	cert, err := cfg.getCertDuringHandshake(strings.ToLower(clientHello.ServerName), true, true)
 	if err == nil {
@@ -166,17 +195,12 @@ func (cfg *Config) getCertificate(name string) (cert Certificate, matched, defau
 	}
 
 	// check the certCache directly to see if the SNI name is
-	// already the key of the certificate it wants! this is vital
-	// for supporting the TLS-SNI challenge, since the tlsSNISolver
-	// just puts the temporary certificate in the instance cache,
-	// with no regard for configs; this also means that the SNI
-	// can contain the hash of a specific cert (chain) it wants
-	// and we will still be able to serve it up
+	// already the key of the certificate it wants; this implies
+	// that the SNI can contain the hash of a specific cert
+	// (chain) it wants and we will still be able to serveit up
 	// (this behavior, by the way, could be controversial as to
 	// whether it complies with RFC 6066 about SNI, but I think
-	// it does soooo...)
-	// NOTE/TODO: TLS-SNI challenge is changing, as of Jan. 2018
-	// but what will be different, if it ever returns, is unclear
+	// it does, soooo...)
 	if directCert, ok := cfg.certCache.cache[name]; ok {
 		cert = directCert
 		matched = true
@@ -477,6 +501,39 @@ func (cfg *Config) renewDynamicCertificate(name string, currentCert Certificate)
 	return cfg.getCertDuringHandshake(name, true, false)
 }
 
+// tryDistributedChallengeSolver is to be called when the clientHello pertains to
+// a TLS-ALPN challenge and a certificate is required to solve it. This method
+// checks the distributed store of challenge info files and, if a matching ServerName
+// is present, it makes a certificate to solve this challenge and returns it.
+// A boolean true is returned if a valid certificate is returned.
+func (cfg *Config) tryDistributedChallengeSolver(clientHello *tls.ClientHelloInfo) (Certificate, bool, error) {
+	filePath := distributedSolver{}.challengeTokensPath(clientHello.ServerName)
+	f, err := os.Open(filePath)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return Certificate{}, false, nil
+		}
+		return Certificate{}, false, fmt.Errorf("opening distributed challenge token file %s: %v", filePath, err)
+	}
+	defer f.Close()
+
+	var chalInfo challengeInfo
+	err = json.NewDecoder(f).Decode(&chalInfo)
+	if err != nil {
+		return Certificate{}, false, fmt.Errorf("decoding challenge token file %s (corrupted?): %v", filePath, err)
+	}
+
+	cert, err := acme.TLSALPNChallengeCert(chalInfo.Domain, chalInfo.KeyAuth)
+	if err != nil {
+		return Certificate{}, false, fmt.Errorf("making TLS-ALPN challenge certificate: %v", err)
+	}
+	if cert == nil {
+		return Certificate{}, false, fmt.Errorf("got nil TLS-ALPN challenge certificate but no error")
+	}
+
+	return Certificate{Certificate: *cert}, true, nil
+}
+
 // ClientHelloInfo is our own version of the standard lib's
 // tls.ClientHelloInfo. As of May 2018, any fields populated
 // by the Go standard library are not guaranteed to have their

caddytls/httphandler.go

@@ -25,7 +25,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 const challengeBasePath = "/.well-known/acme-challenge"
@@ -87,7 +87,7 @@ func HTTPChallengeHandler(w http.ResponseWriter, r *http.Request, listenHost str
 // storage, and attempts to complete the challenge for it. It
 // returns true if the challenge was handled; false otherwise.
 func tryDistributedChallengeSolver(w http.ResponseWriter, r *http.Request) bool {
-	filePath := distributedHTTPSolver{}.challengeTokensPath(r.Host)
+	filePath := distributedSolver{}.challengeTokensPath(r.Host)
 	f, err := os.Open(filePath)
 	if err != nil {
 		if !os.IsNotExist(err) {
@@ -112,7 +112,7 @@ func tryDistributedChallengeSolver(w http.ResponseWriter, r *http.Request) bool
 		w.Header().Add("Content-Type", "text/plain")
 		w.Write([]byte(chalInfo.KeyAuth))
 		r.Close = true
-		log.Printf("[INFO][%s] Served key authentication", chalInfo.Domain)
+		log.Printf("[INFO][%s] Served key authentication (distributed)", chalInfo.Domain)
 		return true
 	}
 

caddytls/maintain.go

@@ -146,7 +146,7 @@ func RenewManagedCertificates(allowPrompts bool) (err error) {
 				// happen to run their maintenance checks at approximately the same times;
 				// both might start renewal at about the same time and do two renewals and one
 				// will overwrite the other. Hence TLS storage plugins. This is sort of a TODO.
-				// NOTE 2: It is super-important to note that the TLS-SNI challenge requires
+				// NOTE 2: It is super-important to note that the TLS-ALPN challenge requires
 				// a write lock on the cache in order to complete its challenge, so it is extra
 				// vital that this renew operation does not happen inside our read lock!
 				renewQueue = append(renewQueue, cert)

caddytls/setup_test.go

@@ -22,7 +22,7 @@ import (
 	"testing"
 
 	"github.com/mholt/caddy"
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 func TestMain(m *testing.M) {

caddytls/tls.go

@@ -39,7 +39,7 @@ import (
 	"strings"
 
 	"github.com/mholt/caddy"
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 // HostQualifies returns true if the hostname alone
@@ -72,7 +72,7 @@ func HostQualifies(hostname string) bool {
 // saveCertResource saves the certificate resource to disk. This
 // includes the certificate file itself, the private key, and the
 // metadata file.
-func saveCertResource(storage Storage, cert acme.CertificateResource) error {
+func saveCertResource(storage Storage, cert *acme.CertificateResource) error {
 	// Save cert, private key, and metadata
 	siteData := &SiteData{
 		Cert: cert.Certificate,
@@ -97,55 +97,63 @@ func Revoke(host string) error {
 	return client.Revoke(host)
 }
 
-// TODO: tls-sni challenge was removed in January 2018, but a variant of it might return
-// // tlsSNISolver is a type that can solve TLS-SNI challenges using
-// // an existing listener and our custom, in-memory certificate cache.
-// type tlsSNISolver struct {
-// 	certCache *certificateCache
-// }
-
-// // Present adds the challenge certificate to the cache.
-// func (s tlsSNISolver) Present(domain, token, keyAuth string) error {
-// 	cert, acmeDomain, err := acme.TLSSNI01ChallengeCert(keyAuth)
-// 	if err != nil {
-// 		return err
-// 	}
-// 	certHash := hashCertificateChain(cert.Certificate)
-// 	s.certCache.Lock()
-// 	s.certCache.cache[acmeDomain] = Certificate{
-// 		Certificate: cert,
-// 		Names:       []string{acmeDomain},
-// 		Hash:        certHash, // perhaps not necesssary
-// 	}
-// 	s.certCache.Unlock()
-// 	return nil
-// }
-
-// // CleanUp removes the challenge certificate from the cache.
-// func (s tlsSNISolver) CleanUp(domain, token, keyAuth string) error {
-// 	_, acmeDomain, err := acme.TLSSNI01ChallengeCert(keyAuth)
-// 	if err != nil {
-// 		return err
-// 	}
-// 	s.certCache.Lock()
-// 	delete(s.certCache.cache, acmeDomain)
-// 	s.certCache.Unlock()
-// 	return nil
-// }
-
-// distributedHTTPSolver allows the HTTP-01 challenge to be solved by
-// an instance other than the one which initiated it. This is useful
-// behind load balancers or in other cluster/fleet configurations.
-// The only requirement is that this (the initiating) instance share
-// the $CADDYPATH/acme folder with the instance that will complete
-// the challenge. Mounting the folder locally should be sufficient.
+// tlsALPNSolver is a type that can solve TLS-ALPN challenges using
+// an existing listener and our custom, in-memory certificate cache.
+type tlsALPNSolver struct {
+	certCache *certificateCache
+}
+
+// Present adds the challenge certificate to the cache.
+func (s tlsALPNSolver) Present(domain, token, keyAuth string) error {
+	cert, err := acme.TLSALPNChallengeCert(domain, keyAuth)
+	if err != nil {
+		return err
+	}
+	certHash := hashCertificateChain(cert.Certificate)
+	s.certCache.Lock()
+	s.certCache.cache[tlsALPNCertKeyName(domain)] = Certificate{
+		Certificate: *cert,
+		Names:       []string{domain},
+		Hash:        certHash, // perhaps not necesssary
+	}
+	s.certCache.Unlock()
+	return nil
+}
+
+// CleanUp removes the challenge certificate from the cache.
+func (s tlsALPNSolver) CleanUp(domain, token, keyAuth string) error {
+	s.certCache.Lock()
+	delete(s.certCache.cache, domain)
+	s.certCache.Unlock()
+	return nil
+}
+
+// tlsALPNCertKeyName returns the key to use when caching a cert
+// for use with the TLS-ALPN ACME challenge. It is simply to help
+// avoid conflicts (although at time of writing, there shouldn't
+// be, since the cert cache is keyed by hash of certificate chain).
+func tlsALPNCertKeyName(sniName string) string {
+	return sniName + ":acme-tls-alpn"
+}
+
+// distributedSolver allows the ACME HTTP-01 and TLS-ALPN challenges
+// to be solved by an instance other than the one which initiated it.
+// This is useful behind load balancers or in other cluster/fleet
+// configurations. The only requirement is that this (the initiating)
+// instance share the $CADDYPATH/acme folder with the instance that
+// will complete the challenge. Mounting the folder locally should be
+// sufficient.
 //
 // Obviously, the instance which completes the challenge must be
-// serving on the HTTPChallengePort to receive and handle the request.
-// The HTTP server which receives it must check if a file exists, e.g.:
-// $CADDYPATH/acme/challenge_tokens/example.com.json, and if so,
-// decode it and use it to serve up the correct response. Caddy's HTTP
-// server does this by default.
+// serving on the HTTPChallengePort for the HTTP-01 challenge or the
+// TLSALPNChallengePort for the TLS-ALPN-01 challenge (or have all
+// the packets port-forwarded) to receive and handle the request. The
+// server which receives the challenge must handle it by checking to
+// see if a file exists, e.g.:
+// $CADDYPATH/acme/challenge_tokens/example.com.json
+// and if so, decode it and use it to serve up the correct response.
+// Caddy's HTTP server does this by default (for HTTP-01) and so does
+// its TLS package (for TLS-ALPN-01).
 //
 // So as long as the folder is shared, this will just work. There are
 // no other requirements. The instances may be on other machines or
@@ -155,29 +163,18 @@ func Revoke(host string) error {
 // This solver works by persisting the token and keyauth information
 // to disk in the shared folder when the authorization is presented,
 // and then deletes it when it is cleaned up.
-type distributedHTTPSolver struct {
-	// The distributed HTTPS solver only works if an instance (either
-	// this one or another one) is already listening and serving on the
-	// HTTPChallengePort. If not -- for example: if this is the only
-	// instance, and it is just starting up and hasn't started serving
-	// yet -- then we still need a listener open with an HTTP server
-	// to handle the challenge request. Set this field to have the
-	// standard HTTPProviderServer open its listener for the duration
-	// of the challenge. Make sure to configure its listen address
-	// correctly.
-	httpProviderServer *acme.HTTPProviderServer
-}
-
-type challengeInfo struct {
-	Domain, Token, KeyAuth string
+type distributedSolver struct {
+	// As the distributedSolver is only a wrapper over the actual
+	// solver, place the actual solver here
+	providerServer ChallengeProvider
 }
 
 // Present adds the challenge certificate to the cache.
-func (dhs distributedHTTPSolver) Present(domain, token, keyAuth string) error {
-	if dhs.httpProviderServer != nil {
-		err := dhs.httpProviderServer.Present(domain, token, keyAuth)
+func (dhs distributedSolver) Present(domain, token, keyAuth string) error {
+	if dhs.providerServer != nil {
+		err := dhs.providerServer.Present(domain, token, keyAuth)
 		if err != nil {
-			return fmt.Errorf("presenting with standard HTTP provider server: %v", err)
+			return fmt.Errorf("presenting with standard provider server: %v", err)
 		}
 	}
 
@@ -199,25 +196,29 @@ func (dhs distributedHTTPSolver) Present(domain, token, keyAuth string) error {
 }
 
 // CleanUp removes the challenge certificate from the cache.
-func (dhs distributedHTTPSolver) CleanUp(domain, token, keyAuth string) error {
-	if dhs.httpProviderServer != nil {
-		err := dhs.httpProviderServer.CleanUp(domain, token, keyAuth)
+func (dhs distributedSolver) CleanUp(domain, token, keyAuth string) error {
+	if dhs.providerServer != nil {
+		err := dhs.providerServer.CleanUp(domain, token, keyAuth)
 		if err != nil {
-			log.Printf("[ERROR] Cleaning up standard HTTP provider server: %v", err)
+			log.Printf("[ERROR] Cleaning up standard provider server: %v", err)
 		}
 	}
 	return os.Remove(dhs.challengeTokensPath(domain))
 }
 
-func (dhs distributedHTTPSolver) challengeTokensPath(domain string) string {
-	domainFile := strings.Replace(strings.ToLower(domain), "*", "wildcard_", -1)
+func (dhs distributedSolver) challengeTokensPath(domain string) string {
+	domainFile := fileSafe(domain)
 	return filepath.Join(dhs.challengeTokensBasePath(), domainFile+".json")
 }
 
-func (dhs distributedHTTPSolver) challengeTokensBasePath() string {
+func (dhs distributedSolver) challengeTokensBasePath() string {
 	return filepath.Join(caddy.AssetsPath(), "acme", "challenge_tokens")
 }
 
+type challengeInfo struct {
+	Domain, Token, KeyAuth string
+}
+
 // ConfigHolder is any type that has a Config; it presumably is
 // connected to a hostname and port on which it is serving.
 type ConfigHolder interface {
@@ -297,8 +298,8 @@ var (
 	// DisableHTTPChallenge will disable all HTTP challenges.
 	DisableHTTPChallenge bool
 
-	// DisableTLSSNIChallenge will disable all TLS-SNI challenges.
-	DisableTLSSNIChallenge bool
+	// DisableTLSALPNChallenge will disable all TLS-ALPN challenges.
+	DisableTLSALPNChallenge bool
 )
 
 var storageProviders = make(map[string]StorageConstructor)

caddytls/tls_test.go

@@ -18,7 +18,7 @@ import (
 	"os"
 	"testing"
 
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 func TestHostQualifies(t *testing.T) {
@@ -116,7 +116,7 @@ func TestSaveCertResource(t *testing.T) {
 	"certStableUrl": "https://example.com/cert/stable"
 }`
 
-	cert := acme.CertificateResource{
+	cert := &acme.CertificateResource{
 		Domain:        domain,
 		CertURL:       "https://example.com/cert",
 		CertStableURL: "https://example.com/cert/stable",
@@ -164,7 +164,7 @@ func TestExistingCertAndKey(t *testing.T) {
 		t.Errorf("Did NOT expect %v to have existing cert or key, but it did", domain)
 	}
 
-	err = saveCertResource(storage, acme.CertificateResource{
+	err = saveCertResource(storage, &acme.CertificateResource{
 		Domain:      domain,
 		PrivateKey:  []byte("key"),
 		Certificate: []byte("cert"),

caddytls/user.go

@@ -27,7 +27,7 @@ import (
 	"os"
 	"strings"
 
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 // User represents a Let's Encrypt user account.

caddytls/user_test.go

@@ -27,7 +27,7 @@ import (
 
 	"os"
 
-	"github.com/xenolf/lego/acmev2"
+	"github.com/xenolf/lego/acme"
 )
 
 func TestUser(t *testing.T) {

vendor/github.com/xenolf/lego/acmev2/challenges.go → vendor/github.com/xenolf/lego/acme/challenges.go

@@ -10,4 +10,6 @@ const (
 	// DNS01 is the "dns-01" ACME challenge https://github.com/ietf-wg-acme/acme/blob/master/draft-ietf-acme-acme.md#dns
 	// Note: DNS01Record returns a DNS record which will fulfill this challenge
 	DNS01 = Challenge("dns-01")
+	// TLSALPN01 is the "tls-alpn-01" ACME challenge https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-01
+	TLSALPN01 = Challenge("tls-alpn-01")
 )

vendor/github.com/xenolf/lego/acmev2/crypto.go → vendor/github.com/xenolf/lego/acme/crypto.go

@@ -9,6 +9,7 @@ import (
 	"crypto/rsa"
 	"crypto/x509"
 	"crypto/x509/pkix"
+	"encoding/asn1"
 	"encoding/base64"
 	"encoding/pem"
 	"errors"
@@ -19,8 +20,6 @@ import (
 	"net/http"
 	"time"
 
-	"encoding/asn1"
-
 	"golang.org/x/crypto/ocsp"
 	jose "gopkg.in/square/go-jose.v2"
 )
@@ -118,6 +117,10 @@ func GetOCSPForCert(bundle []byte) ([]byte, *ocsp.Response, error) {
 	defer req.Body.Close()
 
 	ocspResBytes, err := ioutil.ReadAll(limitReader(req.Body, 1024*1024))
+	if err != nil {
+		return nil, nil, err
+	}
+
 	ocspRes, err := ocsp.ParseResponse(ocspResBytes, issuerCert)
 	if err != nil {
 		return nil, nil, err
@@ -138,7 +141,7 @@ func getKeyAuthorization(token string, key interface{}) (string, error) {
 	// Generate the Key Authorization for the challenge
 	jwk := &jose.JSONWebKey{Key: publicKey}
 	if jwk == nil {
-		return "", errors.New("Could not generate JWK from key")
+		return "", errors.New("could not generate JWK from key")
 	}
 	thumbBytes, err := jwk.Thumbprint(crypto.SHA256)
 	if err != nil {
@@ -173,7 +176,7 @@ func parsePEMBundle(bundle []byte) ([]*x509.Certificate, error) {
 	}
 
 	if len(certificates) == 0 {
-		return nil, errors.New("No certificates were found while parsing the bundle")
+		return nil, errors.New("no certificates were found while parsing the bundle")
 	}
 
 	return certificates, nil
@@ -188,7 +191,7 @@ func parsePEMPrivateKey(key []byte) (crypto.PrivateKey, error) {
 	case "EC PRIVATE KEY":
 		return x509.ParseECPrivateKey(keyBlock.Bytes)
 	default:
-		return nil, errors.New("Unknown PEM header value")
+		return nil, errors.New("unknown PEM header value")
 	}
 }
 
@@ -207,14 +210,12 @@ func generatePrivateKey(keyType KeyType) (crypto.PrivateKey, error) {
 		return rsa.GenerateKey(rand.Reader, 8192)
 	}
 
-	return nil, fmt.Errorf("Invalid KeyType: %s", keyType)
+	return nil, fmt.Errorf("invalid KeyType: %s", keyType)
 }
 
 func generateCsr(privateKey crypto.PrivateKey, domain string, san []string, mustStaple bool) ([]byte, error) {
 	template := x509.CertificateRequest{
-		Subject: pkix.Name{
-			CommonName: domain,
-		},
+		Subject: pkix.Name{CommonName: domain},
 	}
 
 	if len(san) > 0 {
@@ -239,10 +240,8 @@ func pemEncode(data interface{}) []byte {
 		pemBlock = &pem.Block{Type: "EC PRIVATE KEY", Bytes: keyBytes}
 	case *rsa.PrivateKey:
 		pemBlock = &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(key)}
-		break
 	case *x509.CertificateRequest:
 		pemBlock = &pem.Block{Type: "CERTIFICATE REQUEST", Bytes: key.Raw}
-		break
 	case derCertificateBytes:
 		pemBlock = &pem.Block{Type: "CERTIFICATE", Bytes: []byte(data.(derCertificateBytes))}
 	}
@@ -302,8 +301,8 @@ func getCertExpiration(cert []byte) (time.Time, error) {
 	return pCert.NotAfter, nil
 }
 
-func generatePemCert(privKey *rsa.PrivateKey, domain string) ([]byte, error) {
-	derBytes, err := generateDerCert(privKey, time.Time{}, domain)
+func generatePemCert(privKey *rsa.PrivateKey, domain string, extensions []pkix.Extension) ([]byte, error) {
+	derBytes, err := generateDerCert(privKey, time.Time{}, domain, extensions)
 	if err != nil {
 		return nil, err
 	}
@@ -311,7 +310,7 @@ func generatePemCert(privKey *rsa.PrivateKey, domain string) ([]byte, error) {
 	return pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: derBytes}), nil
 }
 
-func generateDerCert(privKey *rsa.PrivateKey, expiration time.Time, domain string) ([]byte, error) {
+func generateDerCert(privKey *rsa.PrivateKey, expiration time.Time, domain string, extensions []pkix.Extension) ([]byte, error) {
 	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
 	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
 	if err != nil {
@@ -333,6 +332,7 @@ func generateDerCert(privKey *rsa.PrivateKey, expiration time.Time, domain strin
 		KeyUsage:              x509.KeyUsageKeyEncipherment,
 		BasicConstraintsValid: true,
 		DNSNames:              []string{domain},
+		ExtraExtensions:       extensions,
 	}
 
 	return x509.CreateCertificate(rand.Reader, &template, &template, &privKey.PublicKey, privKey)

vendor/github.com/xenolf/lego/acmev2/dns_challenge.go → vendor/github.com/xenolf/lego/acme/dns_challenge.go

@@ -5,12 +5,12 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
-	"log"
 	"net"
 	"strings"
 	"time"
 
 	"github.com/miekg/dns"
+	"github.com/xenolf/lego/log"
 )
 
 type preCheckDNSFunc func(fqdn, value string) (bool, error)
@@ -72,10 +72,10 @@ type dnsChallenge struct {
 }
 
 func (s *dnsChallenge) Solve(chlng challenge, domain string) error {
-	logf("[INFO][%s] acme: Trying to solve DNS-01", domain)
+	log.Infof("[%s] acme: Trying to solve DNS-01", domain)
 
 	if s.provider == nil {
-		return errors.New("No DNS Provider configured")
+		return errors.New("no DNS Provider configured")
 	}
 
 	// Generate the Key Authorization for the challenge
@@ -86,18 +86,18 @@ func (s *dnsChallenge) Solve(chlng challenge, domain string) error {
 
 	err = s.provider.Present(domain, chlng.Token, keyAuth)
 	if err != nil {
-		return fmt.Errorf("Error presenting token: %s", err)
+		return fmt.Errorf("error presenting token: %s", err)
 	}
 	defer func() {
 		err := s.provider.CleanUp(domain, chlng.Token, keyAuth)
 		if err != nil {
-			log.Printf("Error cleaning up %s: %v ", domain, err)
+			log.Warnf("Error cleaning up %s: %v ", domain, err)
 		}
 	}()
 
 	fqdn, value, _ := DNS01Record(domain, keyAuth)
 
-	logf("[INFO][%s] Checking DNS record propagation using %+v", domain, RecursiveNameservers)
+	log.Infof("[%s] Checking DNS record propagation using %+v", domain, RecursiveNameservers)
 
 	var timeout, interval time.Duration
 	switch provider := s.provider.(type) {

vendor/github.com/xenolf/lego/acmev2/dns_challenge_manual.go → vendor/github.com/xenolf/lego/acme/dns_challenge_manual.go

@@ -4,6 +4,8 @@ import (
 	"bufio"
 	"fmt"
 	"os"
+
+	"github.com/xenolf/lego/log"
 )
 
 const (
@@ -28,9 +30,9 @@ func (*DNSProviderManual) Present(domain, token, keyAuth string) error {
 		return err
 	}
 
-	logf("[INFO] acme: Please create the following TXT record in your %s zone:", authZone)
-	logf("[INFO] acme: %s", dnsRecord)
-	logf("[INFO] acme: Press 'Enter' when you are done")
+	log.Infof("acme: Please create the following TXT record in your %s zone:", authZone)
+	log.Infof("acme: %s", dnsRecord)
+	log.Infof("acme: Press 'Enter' when you are done")
 
 	reader := bufio.NewReader(os.Stdin)
 	_, _ = reader.ReadString('\n')
@@ -47,7 +49,7 @@ func (*DNSProviderManual) CleanUp(domain, token, keyAuth string) error {
 		return err
 	}
 
-	logf("[INFO] acme: You can now remove this TXT record from your %s zone:", authZone)
-	logf("[INFO] acme: %s", dnsRecord)
+	log.Infof("acme: You can now remove this TXT record from your %s zone:", authZone)
+	log.Infof("acme: %s", dnsRecord)
 	return nil
 }

vendor/github.com/xenolf/lego/acmev2/http.go → vendor/github.com/xenolf/lego/acme/http.go

 package acme
 
 import (
+	"crypto/tls"
+	"crypto/x509"
 	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
+	"io/ioutil"
 	"net"
 	"net/http"
+	"os"
 	"runtime"
 	"strings"
 	"time"
 )
 
-// UserAgent (if non-empty) will be tacked onto the User-Agent string in requests.
-var UserAgent string
-
-// HTTPClient is an HTTP client with a reasonable timeout value.
-var HTTPClient = http.Client{
-	Transport: &http.Transport{
-		Proxy: http.ProxyFromEnvironment,
-		Dial: (&net.Dialer{
-			Timeout:   30 * time.Second,
-			KeepAlive: 30 * time.Second,
-		}).Dial,
-		TLSHandshakeTimeout:   15 * time.Second,
-		ResponseHeaderTimeout: 15 * time.Second,
-		ExpectContinueTimeout: 1 * time.Second,
-	},
-}
+var (
+	// UserAgent (if non-empty) will be tacked onto the User-Agent string in requests.
+	UserAgent string
+
+	// HTTPClient is an HTTP client with a reasonable timeout value and
+	// potentially a custom *x509.CertPool based on the caCertificatesEnvVar
+	// environment variable (see the `initCertPool` function)
+	HTTPClient = http.Client{
+		Transport: &http.Transport{
+			Proxy: http.ProxyFromEnvironment,
+			DialContext: (&net.Dialer{
+				Timeout:   30 * time.Second,
+				KeepAlive: 30 * time.Second,
+			}).DialContext,
+			TLSHandshakeTimeout:   15 * time.Second,
+			ResponseHeaderTimeout: 15 * time.Second,
+			ExpectContinueTimeout: 1 * time.Second,
+			TLSClientConfig: &tls.Config{
+				ServerName: os.Getenv(caServerNameEnvVar),
+				RootCAs:    initCertPool(),
+			},
+		},
+	}
+)
 
 const (
 	// defaultGoUserAgent is the Go HTTP package user agent string. Too
@@ -36,12 +48,46 @@ const (
 
 	// ourUserAgent is the User-Agent of this underlying library package.
 	ourUserAgent = "xenolf-acme"
+
+	// caCertificatesEnvVar is the environment variable name that can be used to
+	// specify the path to PEM encoded CA Certificates that can be used to
+	// authenticate an ACME server with a HTTPS certificate not issued by a CA in
+	// the system-wide trusted root list.
+	caCertificatesEnvVar = "LEGO_CA_CERTIFICATES"
+
+	// caServerNameEnvVar is the environment variable name that can be used to
+	// specify the CA server name that can be used to
+	// authenticate an ACME server with a HTTPS certificate not issued by a CA in
+	// the system-wide trusted root list.
+	caServerNameEnvVar = "LEGO_CA_SERVER_NAME"
 )
 
+// initCertPool creates a *x509.CertPool populated with the PEM certificates
+// found in the filepath specified in the caCertificatesEnvVar OS environment
+// variable. If the caCertificatesEnvVar is not set then initCertPool will
+// return nil. If there is an error creating a *x509.CertPool from the provided
+// caCertificatesEnvVar value then initCertPool will panic.
+func initCertPool() *x509.CertPool {
+	if customCACertsPath := os.Getenv(caCertificatesEnvVar); customCACertsPath != "" {
+		customCAs, err := ioutil.ReadFile(customCACertsPath)
+		if err != nil {
+			panic(fmt.Sprintf("error reading %s=%q: %v",
+				caCertificatesEnvVar, customCACertsPath, err))
+		}
+		certPool := x509.NewCertPool()
+		if ok := certPool.AppendCertsFromPEM(customCAs); !ok {
+			panic(fmt.Sprintf("error creating x509 cert pool from %s=%q: %v",
+				caCertificatesEnvVar, customCACertsPath, err))
+		}
+		return certPool
+	}
+	return nil
+}
+
 // httpHead performs a HEAD request with a proper User-Agent string.
 // The response body (resp.Body) is already closed when this function returns.
 func httpHead(url string) (resp *http.Response, err error) {
-	req, err := http.NewRequest("HEAD", url, nil)
+	req, err := http.NewRequest(http.MethodHead, url, nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to head %q: %v", url, err)
 	}
@@ -59,7 +105,7 @@ func httpHead(url string) (resp *http.Response, err error) {
 // httpPost performs a POST request with a proper User-Agent string.
 // Callers should close resp.Body when done reading from it.
 func httpPost(url string, bodyType string, body io.Reader) (resp *http.Response, err error) {
-	req, err := http.NewRequest("POST", url, body)
+	req, err := http.NewRequest(http.MethodPost, url, body)
 	if err != nil {
 		return nil, fmt.Errorf("failed to post %q: %v", url, err)
 	}
@@ -72,7 +118,7 @@ func httpPost(url string, bodyType string, body io.Reader) (resp *http.Response,
 // httpGet performs a GET request with a proper User-Agent string.
 // Callers should close resp.Body when done reading from it.
 func httpGet(url string) (resp *http.Response, err error) {
-	req, err := http.NewRequest("GET", url, nil)
+	req, err := http.NewRequest(http.MethodGet, url, nil)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get %q: %v", url, err)
 	}
@@ -155,6 +201,6 @@ func postJSON(j *jws, uri string, reqBody, respBody interface{}) (http.Header, e
 
 // userAgent builds and returns the User-Agent string to use in requests.
 func userAgent() string {
-	ua := fmt.Sprintf("%s (%s; %s) %s %s", defaultGoUserAgent, runtime.GOOS, runtime.GOARCH, ourUserAgent, UserAgent)
+	ua := fmt.Sprintf("%s %s (%s; %s) %s", UserAgent, ourUserAgent, runtime.GOOS, runtime.GOARCH, defaultGoUserAgent)
 	return strings.TrimSpace(ua)
 }

vendor/github.com/xenolf/lego/acmev2/http_challenge.go → vendor/github.com/xenolf/lego/acme/http_challenge.go

@@ -2,7 +2,8 @@ package acme
 
 import (
 	"fmt"
-	"log"
+
+	"github.com/xenolf/lego/log"
 )
 
 type httpChallenge struct {
@@ -18,7 +19,7 @@ func HTTP01ChallengePath(token string) string {
 
 func (s *httpChallenge) Solve(chlng challenge, domain string) error {
 
-	logf("[INFO][%s] acme: Trying to solve HTTP-01", domain)
+	log.Infof("[%s] acme: Trying to solve HTTP-01", domain)
 
 	// Generate the Key Authorization for the challenge
 	keyAuth, err := getKeyAuthorization(chlng.Token, s.jws.privKey)
@@ -33,7 +34,7 @@ func (s *httpChallenge) Solve(chlng challenge, domain string) error {
 	defer func() {
 		err := s.provider.CleanUp(domain, chlng.Token, keyAuth)
 		if err != nil {
-			log.Printf("[%s] error cleaning up: %v", domain, err)
+			log.Warnf("[%s] error cleaning up: %v", domain, err)
 		}
 	}()
 

vendor/github.com/xenolf/lego/acmev2/http_challenge_server.go → vendor/github.com/xenolf/lego/acme/http_challenge_server.go

@@ -5,6 +5,8 @@ import (
 	"net"
 	"net/http"
 	"strings"
+
+	"github.com/xenolf/lego/log"
 )
 
 // HTTPProviderServer implements ChallengeProvider for `http-01` challenge
@@ -58,12 +60,12 @@ func (s *HTTPProviderServer) serve(domain, token, keyAuth string) {
 	// For validation it then writes the token the server returned with the challenge
 	mux := http.NewServeMux()
 	mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
-		if strings.HasPrefix(r.Host, domain) && r.Method == "GET" {
+		if strings.HasPrefix(r.Host, domain) && r.Method == http.MethodGet {
 			w.Header().Add("Content-Type", "text/plain")
 			w.Write([]byte(keyAuth))
-			logf("[INFO][%s] Served key authentication", domain)
+			log.Infof("[%s] Served key authentication", domain)
 		} else {
-			logf("[WARN] Received request for domain %s with method %s but the domain did not match any challenge. Please ensure your are passing the HOST header properly.", r.Host, r.Method)
+			log.Warnf("Received request for domain %s with method %s but the domain did not match any challenge. Please ensure your are passing the HOST header properly.", r.Host, r.Method)
 			w.Write([]byte("TEST"))
 		}
 	})

vendor/github.com/xenolf/lego/acmev2/jws.go → vendor/github.com/xenolf/lego/acme/jws.go

@@ -26,13 +26,13 @@ type jws struct {
 func (j *jws) post(url string, content []byte) (*http.Response, error) {
 	signedContent, err := j.signContent(url, content)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to sign content -> %s", err.Error())
+		return nil, fmt.Errorf("failed to sign content -> %s", err.Error())
 	}
 
 	data := bytes.NewBuffer([]byte(signedContent.FullSerialize()))
 	resp, err := httpPost(url, "application/jose+json", data)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to HTTP POST to %s -> %s", url, err.Error())
+		return nil, fmt.Errorf("failed to HTTP POST to %s -> %s", url, err.Error())
 	}
 
 	nonce, nonceErr := getNonceFromResponse(resp)
@@ -77,16 +77,45 @@ func (j *jws) signContent(url string, content []byte) (*jose.JSONWebSignature, e
 
 	signer, err := jose.NewSigner(signKey, &options)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to create jose signer -> %s", err.Error())
+		return nil, fmt.Errorf("failed to create jose signer -> %s", err.Error())
 	}
 
 	signed, err := signer.Sign(content)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to sign content -> %s", err.Error())
+		return nil, fmt.Errorf("failed to sign content -> %s", err.Error())
 	}
 	return signed, nil
 }
 
+func (j *jws) signEABContent(url, kid string, hmac []byte) (*jose.JSONWebSignature, error) {
+	jwk := jose.JSONWebKey{Key: j.privKey}
+	jwkJSON, err := jwk.Public().MarshalJSON()
+	if err != nil {
+		return nil, fmt.Errorf("acme: error encoding eab jwk key: %s", err.Error())
+	}
+
+	signer, err := jose.NewSigner(
+		jose.SigningKey{Algorithm: jose.HS256, Key: hmac},
+		&jose.SignerOptions{
+			EmbedJWK: false,
+			ExtraHeaders: map[jose.HeaderKey]interface{}{
+				"kid": kid,
+				"url": url,
+			},
+		},
+	)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create External Account Binding jose signer -> %s", err.Error())
+	}
+
+	signed, err := signer.Sign(jwkJSON)
+	if err != nil {
+		return nil, fmt.Errorf("failed to External Account Binding sign content -> %s", err.Error())
+	}
+
+	return signed, nil
+}
+
 func (j *jws) Nonce() (string, error) {
 	if nonce, ok := j.nonces.Pop(); ok {
 		return nonce, nil
@@ -122,7 +151,7 @@ func (n *nonceManager) Push(nonce string) {
 func getNonce(url string) (string, error) {
 	resp, err := httpHead(url)
 	if err != nil {
-		return "", fmt.Errorf("Failed to get nonce from HTTP HEAD -> %s", err.Error())
+		return "", fmt.Errorf("failed to get nonce from HTTP HEAD -> %s", err.Error())
 	}
 
 	return getNonceFromResponse(resp)
@@ -131,7 +160,7 @@ func getNonce(url string) (string, error) {
 func getNonceFromResponse(resp *http.Response) (string, error) {
 	nonce := resp.Header.Get("Replay-Nonce")
 	if nonce == "" {
-		return "", fmt.Errorf("Server did not respond with a proper nonce header")
+		return "", fmt.Errorf("server did not respond with a proper nonce header")
 	}
 
 	return nonce, nil

vendor/github.com/xenolf/lego/acmev2/messages.go → vendor/github.com/xenolf/lego/acme/messages.go

 package acme
 
 import (
+	"encoding/json"
 	"time"
 )
 
@@ -26,11 +27,12 @@ type directory struct {
 }
 
 type accountMessage struct {
-	Status               string   `json:"status,omitempty"`
-	Contact              []string `json:"contact,omitempty"`
-	TermsOfServiceAgreed bool     `json:"termsOfServiceAgreed,omitempty"`
-	Orders               string   `json:"orders,omitempty"`
-	OnlyReturnExisting   bool     `json:"onlyReturnExisting,omitempty"`
+	Status                 string          `json:"status,omitempty"`
+	Contact                []string        `json:"contact,omitempty"`
+	TermsOfServiceAgreed   bool            `json:"termsOfServiceAgreed,omitempty"`
+	Orders                 string          `json:"orders,omitempty"`
+	OnlyReturnExisting     bool            `json:"onlyReturnExisting,omitempty"`
+	ExternalAccountBinding json.RawMessage `json:"externalAccountBinding,omitempty"`
 }
 
 type orderResource struct {
@@ -76,9 +78,6 @@ type csrMessage struct {
 	Csr string `json:"csr"`
 }
 
-type emptyObjectMessage struct {
-}
-
 type revokeCertMessage struct {
 	Certificate string `json:"certificate"`
 }

vendor/github.com/xenolf/lego/acme/tls_alpn_challenge.go

+package acme
+
+import (
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/tls"
+	"crypto/x509/pkix"
+	"encoding/asn1"
+	"fmt"
+
+	"github.com/xenolf/lego/log"
+)
+
+// idPeAcmeIdentifierV1 is the SMI Security for PKIX Certification Extension OID referencing the ACME extension.
+// Reference: https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-01#section-5.1
+var idPeAcmeIdentifierV1 = asn1.ObjectIdentifier{1, 3, 6, 1, 5, 5, 7, 1, 30, 1}
+
+type tlsALPNChallenge struct {
+	jws      *jws
+	validate validateFunc
+	provider ChallengeProvider
+}
+
+// Solve manages the provider to validate and solve the challenge.
+func (t *tlsALPNChallenge) Solve(chlng challenge, domain string) error {
+	log.Infof("[%s] acme: Trying to solve TLS-ALPN-01", domain)
+
+	// Generate the Key Authorization for the challenge
+	keyAuth, err := getKeyAuthorization(chlng.Token, t.jws.privKey)
+	if err != nil {
+		return err
+	}
+
+	err = t.provider.Present(domain, chlng.Token, keyAuth)
+	if err != nil {
+		return fmt.Errorf("[%s] error presenting token: %v", domain, err)
+	}
+	defer func() {
+		err := t.provider.CleanUp(domain, chlng.Token, keyAuth)
+		if err != nil {
+			log.Warnf("[%s] error cleaning up: %v", domain, err)
+		}
+	}()
+
+	return t.validate(t.jws, domain, chlng.URL, challenge{Type: chlng.Type, Token: chlng.Token, KeyAuthorization: keyAuth})
+}
+
+// TLSALPNChallengeBlocks returns PEM blocks (certPEMBlock, keyPEMBlock) with the acmeValidation-v1 extension
+// and domain name for the `tls-alpn-01` challenge.
+func TLSALPNChallengeBlocks(domain, keyAuth string) ([]byte, []byte, error) {
+	// Compute the SHA-256 digest of the key authorization.
+	zBytes := sha256.Sum256([]byte(keyAuth))
+
+	value, err := asn1.Marshal(zBytes[:sha256.Size])
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Add the keyAuth digest as the acmeValidation-v1 extension
+	// (marked as critical such that it won't be used by non-ACME software).
+	// Reference: https://tools.ietf.org/html/draft-ietf-acme-tls-alpn-01#section-3
+	extensions := []pkix.Extension{
+		{
+			Id:       idPeAcmeIdentifierV1,
+			Critical: true,
+			Value:    value,
+		},
+	}
+
+	// Generate a new RSA key for the certificates.
+	tempPrivKey, err := generatePrivateKey(RSA2048)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	rsaPrivKey := tempPrivKey.(*rsa.PrivateKey)
+
+	// Generate the PEM certificate using the provided private key, domain, and extra extensions.
+	tempCertPEM, err := generatePemCert(rsaPrivKey, domain, extensions)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Encode the private key into a PEM format. We'll need to use it to generate the x509 keypair.
+	rsaPrivPEM := pemEncode(rsaPrivKey)
+
+	return tempCertPEM, rsaPrivPEM, nil
+}
+
+// TLSALPNChallengeCert returns a certificate with the acmeValidation-v1 extension
+// and domain name for the `tls-alpn-01` challenge.
+func TLSALPNChallengeCert(domain, keyAuth string) (*tls.Certificate, error) {
+	tempCertPEM, rsaPrivPEM, err := TLSALPNChallengeBlocks(domain, keyAuth)
+	if err != nil {
+		return nil, err
+	}
+
+	certificate, err := tls.X509KeyPair(tempCertPEM, rsaPrivPEM)
+	if err != nil {
+		return nil, err
+	}
+
+	return &certificate, nil
+}

vendor/github.com/xenolf/lego/acme/tls_alpn_challenge_server.go

+package acme
+
+import (
+	"crypto/tls"
+	"fmt"
+	"net"
+	"net/http"
+)
+
+const (
+	// ACMETLS1Protocol is the ALPN Protocol ID for the ACME-TLS/1 Protocol.
+	ACMETLS1Protocol = "acme-tls/1"
+
+	// defaultTLSPort is the port that the TLSALPNProviderServer will default to
+	// when no other port is provided.
+	defaultTLSPort = "443"
+)
+
+// TLSALPNProviderServer implements ChallengeProvider for `TLS-ALPN-01`
+// challenge. It may be instantiated without using the NewTLSALPNProviderServer
+// if you want only to use the default values.
+type TLSALPNProviderServer struct {
+	iface    string
+	port     string
+	listener net.Listener
+}
+
+// NewTLSALPNProviderServer creates a new TLSALPNProviderServer 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 NewTLSALPNProviderServer(iface, port string) *TLSALPNProviderServer {
+	return &TLSALPNProviderServer{iface: iface, port: 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 (t *TLSALPNProviderServer) Present(domain, token, keyAuth string) error {
+	if t.port == "" {
+		// Fallback to port 443 if the port was not provided.
+		t.port = defaultTLSPort
+	}
+
+	// Generate the challenge certificate using the provided keyAuth and domain.
+	cert, err := TLSALPNChallengeCert(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-01#section-5.2
+	tlsConf.NextProtos = []string{ACMETLS1Protocol}
+
+	// Create the listener with the created tls.Config.
+	t.listener, err = tls.Listen("tcp", net.JoinHostPort(t.iface, t.port), 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() {
+		http.Serve(t.listener, nil)
+	}()
+
+	return nil
+}
+
+// CleanUp closes the HTTPS server.
+func (t *TLSALPNProviderServer) CleanUp(domain, token, keyAuth string) error {
+	if t.listener == nil {
+		return nil
+	}
+
+	// Server was created, close it.
+	if err := t.listener.Close(); err != nil && err != http.ErrServerClosed {
+		return err
+	}
+
+	return nil
+}

vendor/github.com/xenolf/lego/acmev2/pop_challenge.go

-package acme

vendor/github.com/xenolf/lego/log/LICENSE

+The MIT License (MIT)
+
+Copyright (c) 2015-2017 Sebastian Erhart
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/xenolf/lego/log/logger.go

+package log
+
+import (
+	"log"
+	"os"
+)
+
+// Logger is an optional custom logger.
+var Logger = log.New(os.Stdout, "", log.LstdFlags)
+
+// Fatal writes a log entry.
+// It uses Logger if not nil, otherwise it uses the default log.Logger.
+func Fatal(args ...interface{}) {
+	Logger.Fatal(args...)
+}
+
+// Fatalf writes a log entry.
+// It uses Logger if not nil, otherwise it uses the default log.Logger.
+func Fatalf(format string, args ...interface{}) {
+	Logger.Fatalf(format, args...)
+}
+
+// Print writes a log entry.
+// It uses Logger if not nil, otherwise it uses the default log.Logger.
+func Print(args ...interface{}) {
+	Logger.Print(args...)
+}
+
+// Println writes a log entry.
+// It uses Logger if not nil, otherwise it uses the default log.Logger.
+func Println(args ...interface{}) {
+	Logger.Println(args...)
+}
+
+// Printf writes a log entry.
+// It uses Logger if not nil, otherwise it uses the default log.Logger.
+func Printf(format string, args ...interface{}) {
+	Logger.Printf(format, args...)
+}
+
+// Warnf writes a log entry.
+func Warnf(format string, args ...interface{}) {
+	Printf("[WARN] "+format, args...)
+}
+
+// Infof writes a log entry.
+func Infof(format string, args ...interface{}) {
+	Printf("[INFO] "+format, args...)
+}

vendor/manifest

@@ -167,12 +167,21 @@
 			"notests": true
 		},
 		{
-			"importpath": "github.com/xenolf/lego/acmev2",
+			"importpath": "github.com/xenolf/lego/acme",
 			"repository": "https://github.com/xenolf/lego",
 			"vcs": "git",
-			"revision": "fad2257e11ae4ff31ed03739386873aa405dec2d",
-			"branch": "acmev2",
-			"path": "/acmev2",
+			"revision": "04e2d74406d42a3727e7a132c1a39735ac527f51",
+			"branch": "master",
+			"path": "/acme",
+			"notests": true
+		},
+		{
+			"importpath": "github.com/xenolf/lego/log",
+			"repository": "https://github.com/xenolf/lego",
+			"vcs": "git",
+			"revision": "04e2d74406d42a3727e7a132c1a39735ac527f51",
+			"branch": "master",
+			"path": "log",
 			"notests": true
 		},
 		{