Bug fixes and other improvements to TLS functions

Now attempt to staple OCSP even for certs that don't have an existing staple (issue #605). "tls off" short-circuits tls setup function. Now we call getEmail() when setting up an acme.Client that does renewals, rather than making a new account with empty email address. Check certificate expiry every 12 hours, and OCSP every hour.

caddy/https/certificates.go

@@ -24,7 +24,7 @@ var certCacheMu sync.RWMutex
 // we can be more efficient by extracting the metadata once so it's
 // just there, ready to use.
 type Certificate struct {
-	*tls.Certificate
+	tls.Certificate
 
 	// Names is the list of names this certificate is written for.
 	// The first is the CommonName (if any), the rest are SAN.
@@ -170,7 +170,6 @@ func makeCertificate(certPEMBlock, keyPEMBlock []byte) (Certificate, error) {
 	if len(tlsCert.Certificate) == 0 {
 		return cert, errors.New("certificate is empty")
 	}
-	cert.Certificate = &tlsCert
 
 	// Parse leaf certificate and extract relevant metadata
 	leaf, err := x509.ParseCertificate(tlsCert.Certificate[0])
@@ -198,6 +197,7 @@ func makeCertificate(certPEMBlock, keyPEMBlock []byte) (Certificate, error) {
 		cert.OCSP = ocspResp
 	}
 
+	cert.Certificate = tlsCert
 	return cert, nil
 }
 
@@ -213,7 +213,9 @@ func makeCertificate(certPEMBlock, keyPEMBlock []byte) (Certificate, error) {
 func cacheCertificate(cert Certificate) {
 	certCacheMu.Lock()
 	if _, ok := certCache[""]; !ok {
-		certCache[""] = cert // use as default
+		// use as default
+		certCache[""] = cert
+		cert.Names = append(cert.Names, "")
 	}
 	for len(certCache)+len(cert.Names) > 10000 {
 		// for simplicity, just remove random elements

caddy/https/handshake.go

@@ -23,7 +23,7 @@ import (
 // This function is safe for use as a tls.Config.GetCertificate callback.
 func GetCertificate(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
 	cert, err := getCertDuringHandshake(clientHello.ServerName, false, false)
-	return cert.Certificate, err
+	return &cert.Certificate, err
 }
 
 // GetOrObtainCertificate will get a certificate to satisfy clientHello, even
@@ -35,7 +35,7 @@ func GetCertificate(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error)
 // This function is safe for use as a tls.Config.GetCertificate callback.
 func GetOrObtainCertificate(clientHello *tls.ClientHelloInfo) (*tls.Certificate, error) {
 	cert, err := getCertDuringHandshake(clientHello.ServerName, true, true)
-	return cert.Certificate, err
+	return &cert.Certificate, err
 }
 
 // getCertDuringHandshake will get a certificate for name. It first tries
@@ -122,8 +122,8 @@ func checkLimitsForObtainingNewCerts(name string) error {
 }
 
 // obtainOnDemandCertificate obtains a certificate for name for the given
-// clientHello. If another goroutine has already started obtaining a cert
-// for name, it will wait and use what the other goroutine obtained.
+// name. If another goroutine has already started obtaining a cert for
+// name, it will wait and use what the other goroutine obtained.
 //
 // This function is safe for use by multiple concurrent goroutines.
 func obtainOnDemandCertificate(name string) (Certificate, error) {
@@ -248,7 +248,7 @@ func renewDynamicCertificate(name string) (Certificate, error) {
 
 	log.Printf("[INFO] Renewing certificate for %s", name)
 
-	client, err := NewACMEClient("", false) // renewals don't use email
+	client, err := NewACMEClientGetEmail(server.Config{}, false)
 	if err != nil {
 		return Certificate{}, err
 	}
@@ -295,7 +295,7 @@ var obtainCertWaitChansMu sync.Mutex
 
 // OnDemandIssuedCount is the number of certificates that have been issued
 // on-demand by this process. It is only safe to modify this count atomically.
-// If it reaches max_certs, on-demand issuances will fail.
+// If it reaches onDemandMaxIssue, on-demand issuances will fail.
 var OnDemandIssuedCount = new(int32)
 
 // onDemandMaxIssue is set based on max_certs in tls config. It specifies the

caddy/https/https.go

@@ -12,7 +12,6 @@ import (
 	"net/http"
 	"os"
 	"strings"
-	"time"
 
 	"github.com/mholt/caddy/middleware"
 	"github.com/mholt/caddy/middleware/redirect"
@@ -215,7 +214,7 @@ func hostHasOtherPort(allConfigs []server.Config, thisConfigIdx int, otherPort s
 // all configs.
 func MakePlaintextRedirects(allConfigs []server.Config) []server.Config {
 	for i, cfg := range allConfigs {
-		if (cfg.TLS.Managed || cfg.TLS.OnDemand) &&
+		if cfg.TLS.Managed &&
 			!hostHasOtherPort(allConfigs, i, "80") &&
 			(cfg.Port == "443" || !hostHasOtherPort(allConfigs, i, "443")) {
 			allConfigs = append(allConfigs, redirPlaintextHost(cfg))
@@ -233,15 +232,16 @@ func MakePlaintextRedirects(allConfigs []server.Config) []server.Config {
 // setting up the config may make it look like it
 // doesn't qualify even though it originally did.
 func ConfigQualifies(cfg server.Config) bool {
-	return !cfg.TLS.Manual && // user can provide own cert and key
+	return (!cfg.TLS.Manual || cfg.TLS.OnDemand) && // user might provide own cert and key
 
 		// user can force-disable automatic HTTPS for this host
 		cfg.Scheme != "http" &&
 		cfg.Port != "80" &&
 		cfg.TLS.LetsEncryptEmail != "off" &&
 
-		// we get can't certs for some kinds of hostnames
-		HostQualifies(cfg.Host)
+		// we get can't certs for some kinds of hostnames, but
+		// on-demand TLS allows empty hostnames at startup
+		(HostQualifies(cfg.Host) || cfg.TLS.OnDemand)
 }
 
 // HostQualifies returns true if the hostname alone
@@ -387,20 +387,11 @@ var (
 	CAUrl string
 )
 
-// Some essential values related to the Let's Encrypt process
-const (
-	// AlternatePort is the port on which the acme client will open a
-	// listener and solve the CA's challenges. If this alternate port
-	// is used instead of the default port (80 or 443), then the
-	// default port for the challenge must be forwarded to this one.
-	AlternatePort = "5033"
-
-	// RenewInterval is how often to check certificates for renewal.
-	RenewInterval = 6 * time.Hour
-
-	// OCSPInterval is how often to check if OCSP stapling needs updating.
-	OCSPInterval = 1 * time.Hour
-)
+// AlternatePort is the port on which the acme client will open a
+// listener and solve the CA's challenges. If this alternate port
+// is used instead of the default port (80 or 443), then the
+// default port for the challenge must be forwarded to this one.
+const AlternatePort = "5033"
 
 // KeySize represents the length of a key in bits.
 type KeySize int

caddy/https/maintain.go

@@ -4,9 +4,19 @@ import (
 	"log"
 	"time"
 
+	"github.com/mholt/caddy/server"
+
 	"golang.org/x/crypto/ocsp"
 )
 
+const (
+	// RenewInterval is how often to check certificates for renewal.
+	RenewInterval = 12 * time.Hour
+
+	// OCSPInterval is how often to check if OCSP stapling needs updating.
+	OCSPInterval = 1 * time.Hour
+)
+
 // maintainAssets is a permanently-blocking function
 // that loops indefinitely and, on a regular schedule, checks
 // certificates for expiration and initiates a renewal of certs
@@ -28,7 +38,7 @@ func maintainAssets(stopChan chan struct{}) {
 			log.Println("[INFO] Done checking certificates")
 		case <-ocspTicker.C:
 			log.Println("[INFO] Scanning for stale OCSP staples")
-			updatePreloadedOCSPStaples()
+			updateOCSPStaples()
 			log.Println("[INFO] Done checking OCSP staples")
 		case <-stopChan:
 			renewalTicker.Stop()
@@ -70,7 +80,7 @@ func renewManagedCertificates(allowPrompts bool) (err error) {
 			log.Printf("[INFO] Certificate for %v expires in %v; attempting renewal", cert.Names, timeLeft)
 
 			if client == nil {
-				client, err = NewACMEClient("", allowPrompts) // renewals don't use email
+				client, err = NewACMEClientGetEmail(server.Config{}, allowPrompts)
 				if err != nil {
 					return err
 				}
@@ -116,42 +126,66 @@ func renewManagedCertificates(allowPrompts bool) (err error) {
 	return nil
 }
 
-func updatePreloadedOCSPStaples() {
+func updateOCSPStaples() {
 	// Create a temporary place to store updates
-	// until we release the potentially slow read
-	// lock so we can use a quick write lock.
+	// until we release the potentially long-lived
+	// read lock and use a short-lived write lock.
 	type ocspUpdate struct {
-		rawBytes       []byte
-		parsedResponse *ocsp.Response
+		rawBytes []byte
+		parsed   *ocsp.Response
 	}
 	updated := make(map[string]ocspUpdate)
 
+	// A single SAN certificate maps to multiple names, so we use this
+	// set to make sure we don't waste cycles checking OCSP for the same
+	// certificate multiple times.
+	visited := make(map[string]struct{})
+
 	certCacheMu.RLock()
 	for name, cert := range certCache {
-		// we update OCSP for managed and un-managed certs here, but only
-		// if it has OCSP stapled and only for pre-loaded certificates
-		if cert.OnDemand || cert.OCSP == nil {
+		// skip this certificate if we've already visited it,
+		// and if not, mark all the names as visited
+		if _, ok := visited[name]; ok {
+			continue
+		}
+		for _, n := range cert.Names {
+			visited[n] = struct{}{}
+		}
+
+		// no point in updating OCSP for expired certificates
+		if time.Now().After(cert.NotAfter) {
 			continue
 		}
 
-		// start checking OCSP staple about halfway through validity period for good measure
-		oldNextUpdate := cert.OCSP.NextUpdate
-		refreshTime := cert.OCSP.ThisUpdate.Add(oldNextUpdate.Sub(cert.OCSP.ThisUpdate) / 2)
+		var lastNextUpdate time.Time
+		if cert.OCSP != nil {
+			// start checking OCSP staple about halfway through validity period for good measure
+			lastNextUpdate = cert.OCSP.NextUpdate
+			refreshTime := cert.OCSP.ThisUpdate.Add(lastNextUpdate.Sub(cert.OCSP.ThisUpdate) / 2)
 
-		// only check for updated OCSP validity window if the refresh time is
-		// in the past and the certificate is not expired
-		if time.Now().After(refreshTime) && time.Now().Before(cert.NotAfter) {
-			err := stapleOCSP(&cert, nil)
-			if err != nil {
-				log.Printf("[ERROR] Checking OCSP for %s: %v", name, err)
+			// since OCSP is already stapled, we need only check if we're in that "refresh window"
+			if time.Now().Before(refreshTime) {
 				continue
 			}
+		}
 
-			// if the OCSP response has been updated, we use it
-			if oldNextUpdate != cert.OCSP.NextUpdate {
-				log.Printf("[INFO] Moving validity period of OCSP staple for %s from %v to %v",
-					name, oldNextUpdate, cert.OCSP.NextUpdate)
-				updated[name] = ocspUpdate{rawBytes: cert.Certificate.OCSPStaple, parsedResponse: cert.OCSP}
+		err := stapleOCSP(&cert, nil)
+		if err != nil {
+			if cert.OCSP != nil {
+				// if it was no staple before, that's fine, otherwise we should log the error
+				log.Printf("[ERROR] Checking OCSP for %s: %v", name, err)
+			}
+			continue
+		}
+
+		// By this point, we've obtained the latest OCSP response.
+		// If there was no staple before, or if the response is updated, make
+		// sure we apply the update to all names on the certificate.
+		if lastNextUpdate.IsZero() || lastNextUpdate != cert.OCSP.NextUpdate {
+			log.Printf("[INFO] Advancing OCSP staple for %v from %s to %s",
+				cert.Names, lastNextUpdate, cert.OCSP.NextUpdate)
+			for _, n := range cert.Names {
+				updated[n] = ocspUpdate{rawBytes: cert.Certificate.OCSPStaple, parsed: cert.OCSP}
 			}
 		}
 	}
@@ -161,7 +195,7 @@ func updatePreloadedOCSPStaples() {
 	certCacheMu.Lock()
 	for name, update := range updated {
 		cert := certCache[name]
-		cert.OCSP = update.parsedResponse
+		cert.OCSP = update.parsed
 		cert.Certificate.OCSPStaple = update.rawBytes
 		certCache[name] = cert
 	}

caddy/https/setup.go

@@ -20,12 +20,12 @@ import (
 // are specified by the user in the config file. All the automatic HTTPS
 // stuff comes later outside of this function.
 func Setup(c *setup.Controller) (middleware.Middleware, error) {
-	if c.Scheme == "http" {
+	if c.Port == "80" || c.Scheme == "http" {
 		c.TLS.Enabled = false
 		log.Printf("[WARNING] TLS disabled for %s://%s.", c.Scheme, c.Address())
-	} else {
-		c.TLS.Enabled = true
+		return nil, nil
 	}
+	c.TLS.Enabled = true
 
 	for c.Next() {
 		var certificateFile, keyFile, loadDir, maxCerts string
@@ -38,6 +38,7 @@ func Setup(c *setup.Controller) (middleware.Middleware, error) {
 			// user can force-disable managed TLS this way
 			if c.TLS.LetsEncryptEmail == "off" {
 				c.TLS.Enabled = false
+				return nil, nil
 			}
 		case 2:
 			certificateFile = args[0]
@@ -120,78 +121,8 @@ func Setup(c *setup.Controller) (middleware.Middleware, error) {
 		}
 
 		// load a directory of certificates, if specified
-		// modeled after haproxy: https://cbonte.github.io/haproxy-dconv/configuration-1.5.html#5.1-crt
 		if loadDir != "" {
-			err := filepath.Walk(loadDir, func(path string, info os.FileInfo, err error) error {
-				if err != nil {
-					log.Printf("[WARNING] Unable to traverse into %s; skipping", path)
-					return nil
-				}
-				if info.IsDir() {
-					return nil
-				}
-				if strings.HasSuffix(strings.ToLower(info.Name()), ".pem") {
-					certBuilder, keyBuilder := new(bytes.Buffer), new(bytes.Buffer)
-					var foundKey bool
-
-					bundle, err := ioutil.ReadFile(path)
-					if err != nil {
-						return err
-					}
-
-					for {
-						// Decode next block so we can see what type it is
-						var derBlock *pem.Block
-						derBlock, bundle = pem.Decode(bundle)
-						if derBlock == nil {
-							break
-						}
-
-						if derBlock.Type == "CERTIFICATE" {
-							// Re-encode certificate as PEM, appending to certificate chain
-							pem.Encode(certBuilder, derBlock)
-						} else if derBlock.Type == "EC PARAMETERS" {
-							// EC keys are composed of two blocks: parameters and key
-							// (parameter block should come first)
-							if !foundKey {
-								// Encode parameters
-								pem.Encode(keyBuilder, derBlock)
-
-								// Key must immediately follow
-								derBlock, bundle = pem.Decode(bundle)
-								if derBlock == nil || derBlock.Type != "EC PRIVATE KEY" {
-									return c.Errf("%s: expected elliptic private key to immediately follow EC parameters", path)
-								}
-								pem.Encode(keyBuilder, derBlock)
-								foundKey = true
-							}
-						} else if derBlock.Type == "PRIVATE KEY" || strings.HasSuffix(derBlock.Type, " PRIVATE KEY") {
-							// RSA key
-							if !foundKey {
-								pem.Encode(keyBuilder, derBlock)
-								foundKey = true
-							}
-						} else {
-							return c.Errf("%s: unrecognized PEM block type: %s", path, derBlock.Type)
-						}
-					}
-
-					certPEMBytes, keyPEMBytes := certBuilder.Bytes(), keyBuilder.Bytes()
-					if len(certPEMBytes) == 0 {
-						return c.Errf("%s: failed to parse PEM data", path)
-					}
-					if len(keyPEMBytes) == 0 {
-						return c.Errf("%s: no private key block found", path)
-					}
-
-					err = cacheUnmanagedCertificatePEMBytes(certPEMBytes, keyPEMBytes)
-					if err != nil {
-						return c.Errf("%s: failed to load cert and key for %s: %v", path, c.Host, err)
-					}
-					log.Printf("[INFO] Successfully loaded TLS assets from %s", path)
-				}
-				return nil
-			})
+			err := loadCertsInDir(c, loadDir)
 			if err != nil {
 				return nil, err
 			}
@@ -203,6 +134,86 @@ func Setup(c *setup.Controller) (middleware.Middleware, error) {
 	return nil, nil
 }
 
+// loadCertsInDir loads all the certificates/keys in dir, as long as
+// the file ends with .pem. This method of loading certificates is
+// modeled after haproxy, which expects the certificate and key to
+// be bundled into the same file:
+// https://cbonte.github.io/haproxy-dconv/configuration-1.5.html#5.1-crt
+//
+// This function may write to the log as it walks the directory tree.
+func loadCertsInDir(c *setup.Controller, dir string) error {
+	return filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			log.Printf("[WARNING] Unable to traverse into %s; skipping", path)
+			return nil
+		}
+		if info.IsDir() {
+			return nil
+		}
+		if strings.HasSuffix(strings.ToLower(info.Name()), ".pem") {
+			certBuilder, keyBuilder := new(bytes.Buffer), new(bytes.Buffer)
+			var foundKey bool // use only the first key in the file
+
+			bundle, err := ioutil.ReadFile(path)
+			if err != nil {
+				return err
+			}
+
+			for {
+				// Decode next block so we can see what type it is
+				var derBlock *pem.Block
+				derBlock, bundle = pem.Decode(bundle)
+				if derBlock == nil {
+					break
+				}
+
+				if derBlock.Type == "CERTIFICATE" {
+					// Re-encode certificate as PEM, appending to certificate chain
+					pem.Encode(certBuilder, derBlock)
+				} else if derBlock.Type == "EC PARAMETERS" {
+					// EC keys generated from openssl can be composed of two blocks:
+					// parameters and key (parameter block should come first)
+					if !foundKey {
+						// Encode parameters
+						pem.Encode(keyBuilder, derBlock)
+
+						// Key must immediately follow
+						derBlock, bundle = pem.Decode(bundle)
+						if derBlock == nil || derBlock.Type != "EC PRIVATE KEY" {
+							return c.Errf("%s: expected elliptic private key to immediately follow EC parameters", path)
+						}
+						pem.Encode(keyBuilder, derBlock)
+						foundKey = true
+					}
+				} else if derBlock.Type == "PRIVATE KEY" || strings.HasSuffix(derBlock.Type, " PRIVATE KEY") {
+					// RSA key
+					if !foundKey {
+						pem.Encode(keyBuilder, derBlock)
+						foundKey = true
+					}
+				} else {
+					return c.Errf("%s: unrecognized PEM block type: %s", path, derBlock.Type)
+				}
+			}
+
+			certPEMBytes, keyPEMBytes := certBuilder.Bytes(), keyBuilder.Bytes()
+			if len(certPEMBytes) == 0 {
+				return c.Errf("%s: failed to parse PEM data", path)
+			}
+			if len(keyPEMBytes) == 0 {
+				return c.Errf("%s: no private key block found", path)
+			}
+
+			err = cacheUnmanagedCertificatePEMBytes(certPEMBytes, keyPEMBytes)
+			if err != nil {
+				return c.Errf("%s: failed to load cert and key for %s: %v", path, c.Host, err)
+			}
+			log.Printf("[INFO] Successfully loaded TLS assets from %s", path)
+		}
+		return nil
+	})
+}
+
 // setDefaultTLSParams sets the default TLS cipher suites, protocol versions,
 // and server preferences of a server.Config if they were not previously set
 // (it does not overwrite; only fills in missing values). It will also set the
@@ -231,7 +242,7 @@ func setDefaultTLSParams(c *server.Config) {
 
 	// Default TLS port is 443; only use if port is not manually specified,
 	// TLS is enabled, and the host is not localhost
-	if c.Port == "" && c.TLS.Enabled && !c.TLS.Manual && c.Host != "localhost" {
+	if c.Port == "" && c.TLS.Enabled && (!c.TLS.Manual || c.TLS.OnDemand) && c.Host != "localhost" {
 		c.Port = "443"
 	}
 }

server/config.go

@@ -68,7 +68,7 @@ type TLSConfig struct {
 	Enabled                  bool // will be set to true if TLS is enabled
 	LetsEncryptEmail         string
 	Manual                   bool // will be set to true if user provides own certs and keys
-	Managed                  bool // will be set to true if config qualifies for automatic/managed HTTPS
+	Managed                  bool // will be set to true if config qualifies for implicit automatic/managed HTTPS
 	OnDemand                 bool // will be set to true if user enables on-demand TLS (obtain certs during handshakes)
 	Ciphers                  []uint16
 	ProtocolMinVersion       uint16

server/server.go

@@ -63,15 +63,7 @@ func New(addr string, configs []Config, gracefulTimeout time.Duration) (*Server,
 	var useTLS, useOnDemandTLS bool
 	if len(configs) > 0 {
 		useTLS = configs[0].TLS.Enabled
-		if useTLS {
-			host, _, err := net.SplitHostPort(addr)
-			if err != nil {
-				host = addr
-			}
-			if host == "" && configs[0].TLS.OnDemand {
-				useOnDemandTLS = true
-			}
-		}
+		useOnDemandTLS = configs[0].TLS.OnDemand
 	}
 
 	s := &Server{