update dependencies

vendor/golang.org/x/crypto/acme/acme.go

@@ -142,7 +142,7 @@ func (c *Client) Discover(ctx context.Context) (Directory, error) {
 //
 // In the case where CA server does not provide the issued certificate in the response,
 // CreateCert will poll certURL using c.FetchCert, which will result in additional round-trips.
-// In such scenario the caller can cancel the polling with ctx.
+// In such a scenario, the caller can cancel the polling with ctx.
 //
 // CreateCert returns an error if the CA's response or chain was unreasonably large.
 // Callers are encouraged to parse the returned value to ensure the certificate is valid and has the expected features.
@@ -257,7 +257,7 @@ func (c *Client) RevokeCert(ctx context.Context, key crypto.Signer, cert []byte,
 func AcceptTOS(tosURL string) bool { return true }
 
 // Register creates a new account registration by following the "new-reg" flow.
-// It returns registered account. The account is not modified.
+// It returns the registered account. The account is not modified.
 //
 // The registration may require the caller to agree to the CA's Terms of Service (TOS).
 // If so, and the account has not indicated the acceptance of the terms (see Account for details),
@@ -995,6 +995,7 @@ func keyAuth(pub crypto.PublicKey, token string) (string, error) {
 
 // tlsChallengeCert creates a temporary certificate for TLS-SNI challenges
 // with the given SANs and auto-generated public/private key pair.
+// The Subject Common Name is set to the first SAN to aid debugging.
 // To create a cert with a custom key pair, specify WithKey option.
 func tlsChallengeCert(san []string, opt []CertOption) (tls.Certificate, error) {
 	var (
@@ -1033,6 +1034,9 @@ func tlsChallengeCert(san []string, opt []CertOption) (tls.Certificate, error) {
 		}
 	}
 	tmpl.DNSNames = san
+	if len(san) > 0 {
+		tmpl.Subject.CommonName = san[0]
+	}
 
 	der, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, key.Public(), key)
 	if err != nil {

vendor/golang.org/x/crypto/acme/acme_test.go

@@ -1186,6 +1186,9 @@ func TestTLSSNI01ChallengeCert(t *testing.T) {
 	if cert.DNSNames[0] != name {
 		t.Errorf("cert.DNSNames[0] != name: %q vs %q", cert.DNSNames[0], name)
 	}
+	if cn := cert.Subject.CommonName; cn != san {
+		t.Errorf("cert.Subject.CommonName = %q; want %q", cn, san)
+	}
 }
 
 func TestTLSSNI02ChallengeCert(t *testing.T) {
@@ -1219,6 +1222,9 @@ func TestTLSSNI02ChallengeCert(t *testing.T) {
 	if i >= len(cert.DNSNames) || cert.DNSNames[i] != name {
 		t.Errorf("%v doesn't have %q", cert.DNSNames, name)
 	}
+	if cn := cert.Subject.CommonName; cn != sanA {
+		t.Errorf("CommonName = %q; want %q", cn, sanA)
+	}
 }
 
 func TestTLSChallengeCertOpt(t *testing.T) {

vendor/golang.org/x/crypto/acme/autocert/autocert.go

@@ -83,8 +83,10 @@ func defaultHostPolicy(context.Context, string) error {
 // It obtains and refreshes certificates automatically,
 // as well as providing them to a TLS server via tls.Config.
 //
-// To preserve issued certificates and improve overall performance,
-// use a cache implementation of Cache. For instance, DirCache.
+// You must specify a cache implementation, such as DirCache,
+// to reuse obtained certificates across program restarts.
+// Otherwise your server is very likely to exceed the certificate
+// issuer's request rate limits.
 type Manager struct {
 	// Prompt specifies a callback function to conditionally accept a CA's Terms of Service (TOS).
 	// The registration may require the caller to agree to the CA's TOS.
@@ -369,7 +371,7 @@ func (m *Manager) createCert(ctx context.Context, domain string) (*tls.Certifica
 
 	// We are the first; state is locked.
 	// Unblock the readers when domain ownership is verified
-	// and the we got the cert or the process failed.
+	// and we got the cert or the process failed.
 	defer state.Unlock()
 	state.locked = false
 
@@ -437,7 +439,7 @@ func (m *Manager) certState(domain string) (*certState, error) {
 	return state, nil
 }
 
-// authorizedCert starts domain ownership verification process and requests a new cert upon success.
+// authorizedCert starts the domain ownership verification process and requests a new cert upon success.
 // The key argument is the certificate private key.
 func (m *Manager) authorizedCert(ctx context.Context, key crypto.Signer, domain string) (der [][]byte, leaf *x509.Certificate, err error) {
 	if err := m.verify(ctx, domain); err != nil {

vendor/golang.org/x/crypto/acme/autocert/example_test.go

@@ -23,6 +23,7 @@ func ExampleNewListener() {
 
 func ExampleManager() {
 	m := autocert.Manager{
+		Cache:      autocert.DirCache("secret-dir"),
 		Prompt:     autocert.AcceptTOS,
 		HostPolicy: autocert.HostWhitelist("example.org"),
 	}