Revert "Require Go 1.16"

This reverts commit 0e87d64ffc.

certificate/store.go

@@ -6,53 +6,55 @@ import (
 	"crypto/x509/pkix"
 	"errors"
 	"fmt"
+	"os"
 	"path/filepath"
 	"strings"
 	"sync"
 	"time"
 )
 
-// A Store represents a certificate store.
-// It generates certificates as needed and automatically rotates expired certificates.
+// A Store represents a TLS certificate store.
 // The zero value for Store is an empty store ready to use.
 //
-// Certificate scopes must be registered with Register before calling Get or Load.
-// This prevents the Store from creating or loading unnecessary certificates.
+// Store can be used to store server certificates.
+// Servers should provide a hostname or wildcard pattern as a certificate scope.
+// Servers will most likely use the methods Register, Load and Get.
+//
+// Store can also be used to store client certificates.
+// Clients should provide a hostname as a certificate scope.
+// Clients will most likely use the methods Add, Load, and Lookup.
 //
 // Store is safe for concurrent use by multiple goroutines.
 type Store struct {
-	// CreateCertificate, if not nil, is called to create a new certificate
-	// to replace a missing or expired certificate. If CreateCertificate
-	// is nil, a certificate with a duration of 1 year will be created.
+	// CreateCertificate, if not nil, is called by Get to create a new
+	// certificate to replace a missing or expired certificate.
 	// The provided scope is suitable for use in a certificate's DNSNames.
 	CreateCertificate func(scope string) (tls.Certificate, error)
 
-	certs map[string]tls.Certificate
-	path  string
-	mu    sync.RWMutex
+	scopes map[string]struct{}
+	certs  map[string]tls.Certificate
+	path   string
+	mu     sync.RWMutex
 }
 
 // Register registers the provided scope with the certificate store.
 // The scope can either be a hostname or a wildcard pattern (e.g. "*.example.com").
 // To accept all hostnames, use the special pattern "*".
+//
+// Calls to Get will only succeed for registered scopes.
+// Other methods are not affected.
 func (s *Store) Register(scope string) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	if s.certs == nil {
-		s.certs = make(map[string]tls.Certificate)
+	if s.scopes == nil {
+		s.scopes = make(map[string]struct{})
 	}
-	s.certs[scope] = tls.Certificate{}
+	s.scopes[scope] = struct{}{}
 }
 
-// Add adds a certificate with the given scope to the certificate store.
-// If a certificate for the given scope already exists, Add will overwrite it.
+// Add registers the certificate for the given scope.
+// If a certificate already exists for scope, Add will overwrite it.
 func (s *Store) Add(scope string, cert tls.Certificate) error {
-	s.mu.Lock()
-	defer s.mu.Unlock()
-	if s.certs == nil {
-		s.certs = make(map[string]tls.Certificate)
-	}
-
 	// Parse certificate if not already parsed
 	if cert.Leaf == nil {
 		parsed, err := x509.ParseCertificate(cert.Certificate[0])
@@ -62,6 +64,22 @@ func (s *Store) Add(scope string, cert tls.Certificate) error {
 		cert.Leaf = parsed
 	}
 
+	if err := s.write(scope, cert); err != nil {
+		return err
+	}
+
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.certs == nil {
+		s.certs = make(map[string]tls.Certificate)
+	}
+	s.certs[scope] = cert
+	return nil
+}
+
+func (s *Store) write(scope string, cert tls.Certificate) error {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
 	if s.path != "" {
 		certPath := filepath.Join(s.path, scope+".crt")
 		keyPath := filepath.Join(s.path, scope+".key")
@@ -69,35 +87,37 @@ func (s *Store) Add(scope string, cert tls.Certificate) error {
 			return err
 		}
 	}
-
-	s.certs[scope] = cert
 	return nil
 }
 
 // Get retrieves a certificate for the given hostname.
 // If no matching scope has been registered, Get returns an error.
 // Get generates new certificates as needed and rotates expired certificates.
+// It calls CreateCertificate to create a new certificate if it is not nil,
+// otherwise it creates certificates with a duration of 100 years.
 //
 // Get is suitable for use in a gemini.Server's GetCertificate field.
 func (s *Store) Get(hostname string) (*tls.Certificate, error) {
 	s.mu.RLock()
-	defer s.mu.RUnlock()
-	cert, ok := s.certs[hostname]
+	_, ok := s.scopes[hostname]
 	if !ok {
 		// Try wildcard
 		wildcard := strings.SplitN(hostname, ".", 2)
 		if len(wildcard) == 2 {
 			hostname = "*." + wildcard[1]
-			cert, ok = s.certs[hostname]
+			_, ok = s.scopes[hostname]
 		}
 	}
 	if !ok {
 		// Try "*"
-		cert, ok = s.certs["*"]
+		_, ok = s.scopes["*"]
 	}
 	if !ok {
+		s.mu.RUnlock()
 		return nil, errors.New("unrecognized scope")
 	}
+	cert := s.certs[hostname]
+	s.mu.RUnlock()
 
 	// If the certificate is empty or expired, generate a new one.
 	if cert.Leaf == nil || cert.Leaf.NotAfter.Before(time.Now()) {
@@ -114,6 +134,14 @@ func (s *Store) Get(hostname string) (*tls.Certificate, error) {
 	return &cert, nil
 }
 
+// Lookup returns the certificate for the provided scope.
+func (s *Store) Lookup(scope string) (tls.Certificate, bool) {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+	cert, ok := s.certs[scope]
+	return cert, ok
+}
+
 func (s *Store) createCertificate(scope string) (tls.Certificate, error) {
 	if s.CreateCertificate != nil {
 		return s.CreateCertificate(scope)
@@ -123,7 +151,7 @@ func (s *Store) createCertificate(scope string) (tls.Certificate, error) {
 		Subject: pkix.Name{
 			CommonName: scope,
 		},
-		Duration: 365 * 24 * time.Hour,
+		Duration: 100 * 365 * 24 * time.Hour,
 	})
 }
 
@@ -132,26 +160,31 @@ func (s *Store) createCertificate(scope string) (tls.Certificate, error) {
 // The path should lead to a directory containing certificates
 // and private keys named "scope.crt" and "scope.key" respectively,
 // where "scope" is the scope of the certificate.
-// Certificates with scopes that have not been registered will be ignored.
 func (s *Store) Load(path string) error {
+	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
+		return err
+	}
+
+	path = filepath.Clean(path)
 	matches, err := filepath.Glob(filepath.Join(path, "*.crt"))
 	if err != nil {
 		return err
 	}
 	for _, crtPath := range matches {
-		scope := strings.TrimSuffix(filepath.Base(crtPath), ".crt")
-		if _, ok := s.certs[scope]; !ok {
-			continue
-		}
-
 		keyPath := strings.TrimSuffix(crtPath, ".crt") + ".key"
 		cert, err := tls.LoadX509KeyPair(crtPath, keyPath)
 		if err != nil {
 			continue
 		}
+
+		scope := strings.TrimPrefix(crtPath, path)
+		scope = strings.TrimPrefix(scope, "/")
+		scope = strings.TrimSuffix(scope, ".crt")
 		s.Add(scope, cert)
 	}
-	s.SetPath(path)
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	s.path = path
 	return nil
 }
 
@@ -170,5 +203,5 @@ func (s *Store) Entries() map[string]tls.Certificate {
 func (s *Store) SetPath(path string) {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	s.path = path
+	s.path = filepath.Clean(path)
 }

client.go

@@ -6,7 +6,6 @@ import (
 	"crypto/x509"
 	"net"
 	"net/url"
-	"time"
 	"unicode/utf8"
 
 	"golang.org/x/net/idna"
@@ -14,10 +13,10 @@ import (
 
 // A Client is a Gemini client. Its zero value is a usable client.
 type Client struct {
-	// TrustCertificate is called to determine whether the client
-	// should trust the certificate provided by the server.
-	// If TrustCertificate is nil, the client will accept any certificate.
-	// If the returned error is not nil, the certificate will not be trusted
+	// TrustCertificate is called to determine whether the client should
+	// trust the certificate provided by the server.
+	// If TrustCertificate is nil or returns nil, the client will accept
+	// any certificate. Otherwise, the certificate will not be trusted
 	// and the request will be aborted.
 	//
 	// See the tofu submodule for an implementation of trust on first use.
@@ -29,14 +28,14 @@ type Client struct {
 }
 
 // Get sends a Gemini request for the given URL.
-// If the provided context is canceled or times out, the request
-// will be aborted and the context's error will be returned.
+// The context controls the entire lifetime of a request and its response:
+// obtaining a connection, sending the request, and reading the response
+// header and body.
 //
 // An error is returned if there was a Gemini protocol error.
 // A non-2x status code doesn't cause an error.
 //
-// If the returned error is nil, the Response will contain a non-nil Body
-// which the user is expected to close.
+// If the returned error is nil, the user is expected to close the Response.
 //
 // For more control over requests, use NewRequest and Client.Do.
 func (c *Client) Get(ctx context.Context, url string) (*Response, error) {
@@ -48,16 +47,14 @@ func (c *Client) Get(ctx context.Context, url string) (*Response, error) {
 }
 
 // Do sends a Gemini request and returns a Gemini response.
-// If the provided context is canceled or times out, the request
-// will be aborted and the context's error will be returned.
+// The context controls the entire lifetime of a request and its response:
+// obtaining a connection, sending the request, and reading the response
+// header and body.
 //
 // An error is returned if there was a Gemini protocol error.
 // A non-2x status code doesn't cause an error.
 //
-// If the returned error is nil, the Response will contain a non-nil Body
-// which the user is expected to close.
-//
-// Generally Get will be used instead of Do.
+// If the returned error is nil, the user is expected to close the Response.
 func (c *Client) Do(ctx context.Context, req *Request) (*Response, error) {
 	if ctx == nil {
 		panic("nil context")
@@ -79,9 +76,10 @@ func (c *Client) Do(ctx context.Context, req *Request) (*Response, error) {
 
 		// Use the new URL in the request so that the server gets
 		// the punycoded hostname
-		req = &Request{
-			URL: u,
-		}
+		r := new(Request)
+		*r = *req
+		r.URL = u
+		req = r
 	}
 
 	// Use request host if provided
@@ -124,7 +122,7 @@ func (c *Client) Do(ctx context.Context, req *Request) (*Response, error) {
 
 	res := make(chan result, 1)
 	go func() {
-		resp, err := c.do(conn, req)
+		resp, err := c.do(ctx, conn, req)
 		res <- result{resp, err}
 	}()
 
@@ -133,27 +131,40 @@ func (c *Client) Do(ctx context.Context, req *Request) (*Response, error) {
 		conn.Close()
 		return nil, ctx.Err()
 	case r := <-res:
+		if r.err != nil {
+			conn.Close()
+		}
 		return r.resp, r.err
 	}
 }
 
-func (c *Client) do(conn net.Conn, req *Request) (*Response, error) {
+func (c *Client) do(ctx context.Context, conn net.Conn, req *Request) (*Response, error) {
+	ctx, cancel := context.WithCancel(ctx)
+	done := ctx.Done()
+	w := &contextWriter{
+		ctx:    ctx,
+		done:   done,
+		cancel: cancel,
+		wc:     conn,
+	}
+	rc := &contextReader{
+		ctx:    ctx,
+		done:   done,
+		cancel: cancel,
+		rc:     conn,
+	}
+
 	// Write the request
-	if err := req.Write(conn); err != nil {
+	if _, err := req.WriteTo(w); err != nil {
 		return nil, err
 	}
 
 	// Read the response
-	resp, err := ReadResponse(conn)
+	resp, err := ReadResponse(rc)
 	if err != nil {
 		return nil, err
 	}
-
-	// Store TLS connection state
-	if tlsConn, ok := conn.(*tls.Conn); ok {
-		state := tlsConn.ConnectionState()
-		resp.TLS = &state
-	}
+	resp.conn = conn
 
 	return resp, nil
 }
@@ -166,17 +177,9 @@ func (c *Client) dialContext(ctx context.Context, network, addr string) (net.Con
 }
 
 func (c *Client) verifyConnection(cs tls.ConnectionState, hostname string) error {
-	cert := cs.PeerCertificates[0]
-	// Verify hostname
-	if err := verifyHostname(cert, hostname); err != nil {
-		return err
-	}
-	// Check expiration date
-	if !time.Now().Before(cert.NotAfter) {
-		return ErrCertificateExpired
-	}
 	// See if the client trusts the certificate
 	if c.TrustCertificate != nil {
+		cert := cs.PeerCertificates[0]
 		return c.TrustCertificate(hostname, cert)
 	}
 	return nil

doc.go

@@ -4,7 +4,8 @@ Package gemini provides Gemini client and server implementations.
 Client is a Gemini client.
 
 	client := &gemini.Client{}
-	resp, err := client.Get("gemini://example.com")
+	ctx := context.Background()
+	resp, err := client.Get(ctx, "gemini://example.com")
 	if err != nil {
 		// handle error
 	}
@@ -21,16 +22,17 @@ Server is a Gemini server.
 Servers should be configured with certificates:
 
 	certificates := &certificate.Store{}
+	certificates.Register("localhost")
 	err := certificates.Load("/var/lib/gemini/certs")
 	if err != nil {
 		// handle error
 	}
-	server.GetCertificate = certificates.GetCertificate
+	server.GetCertificate = certificates.Get
 
-ServeMux is a Gemini request multiplexer.
-ServeMux can handle requests for multiple hosts and schemes.
+Mux is a Gemini request multiplexer.
+Mux can handle requests for multiple hosts and schemes.
 
-	mux := &gemini.ServeMux{}
+	mux := &gemini.Mux{}
 	mux.HandleFunc("example.com", func(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
 		fmt.Fprint(w, "Welcome to example.com")
 	})
@@ -44,7 +46,8 @@ ServeMux can handle requests for multiple hosts and schemes.
 
 To start the server, call ListenAndServe:
 
-	err := server.ListenAndServe(context.Background())
+	ctx := context.Background()
+	err := server.ListenAndServe(ctx)
 	if err != nil {
 		// handle error
 	}

examples/auth.go

@@ -30,7 +30,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	mux := &gemini.ServeMux{}
+	mux := &gemini.Mux{}
 	mux.HandleFunc("/", profile)
 	mux.HandleFunc("/username", changeUsername)
 
@@ -52,11 +52,12 @@ func fingerprint(cert *x509.Certificate) string {
 }
 
 func profile(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
-	if len(r.TLS.PeerCertificates) == 0 {
+	tls := r.TLS()
+	if len(tls.PeerCertificates) == 0 {
 		w.WriteHeader(gemini.StatusCertificateRequired, "Certificate required")
 		return
 	}
-	fingerprint := fingerprint(r.TLS.PeerCertificates[0])
+	fingerprint := fingerprint(tls.PeerCertificates[0])
 	user, ok := users[fingerprint]
 	if !ok {
 		user = &User{}
@@ -67,7 +68,8 @@ func profile(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
 }
 
 func changeUsername(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
-	if len(r.TLS.PeerCertificates) == 0 {
+	tls := r.TLS()
+	if len(tls.PeerCertificates) == 0 {
 		w.WriteHeader(gemini.StatusCertificateRequired, "Certificate required")
 		return
 	}
@@ -77,7 +79,7 @@ func changeUsername(ctx context.Context, w gemini.ResponseWriter, r *gemini.Requ
 		w.WriteHeader(gemini.StatusInput, "Username")
 		return
 	}
-	fingerprint := fingerprint(r.TLS.PeerCertificates[0])
+	fingerprint := fingerprint(tls.PeerCertificates[0])
 	user, ok := users[fingerprint]
 	if !ok {
 		user = &User{}

examples/client.go

@@ -6,7 +6,6 @@ package main
 
 import (
 	"bufio"
-	"bytes"
 	"context"
 	"crypto/x509"
 	"errors"
@@ -16,7 +15,6 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
-	"time"
 
 	"git.sr.ht/~adnano/go-gemini"
 	"git.sr.ht/~adnano/go-gemini/tofu"
@@ -61,15 +59,14 @@ Otherwise, this should be safe to trust.
 => `
 
 func trustCertificate(hostname string, cert *x509.Certificate) error {
-	host := tofu.NewHost(hostname, cert.Raw, cert.NotAfter)
-
+	host := tofu.NewHost(hostname, cert.Raw)
 	knownHost, ok := hosts.Lookup(hostname)
-	if ok && time.Now().Before(knownHost.Expires) {
+	if ok {
 		// Check fingerprint
-		if bytes.Equal(knownHost.Fingerprint, host.Fingerprint) {
-			return nil
+		if knownHost.Fingerprint != host.Fingerprint {
+			return errors.New("error: fingerprint does not match!")
 		}
-		return errors.New("error: fingerprint does not match!")
+		return nil
 	}
 
 	fmt.Printf(trustPrompt, hostname, host.Fingerprint)
@@ -87,7 +84,7 @@ func trustCertificate(hostname string, cert *x509.Certificate) error {
 	}
 }
 
-func getInput(prompt string, sensitive bool) (input string, ok bool) {
+func getInput(prompt string) (input string, ok bool) {
 	fmt.Printf("%s ", prompt)
 	scanner.Scan()
 	return scanner.Text(), true
@@ -97,14 +94,15 @@ func do(req *gemini.Request, via []*gemini.Request) (*gemini.Response, error) {
 	client := gemini.Client{
 		TrustCertificate: trustCertificate,
 	}
-	resp, err := client.Do(context.Background(), req)
+	ctx := context.Background()
+	resp, err := client.Do(ctx, req)
 	if err != nil {
 		return resp, err
 	}
 
 	switch resp.Status.Class() {
 	case gemini.StatusInput:
-		input, ok := getInput(resp.Meta, resp.Status == gemini.StatusSensitiveInput)
+		input, ok := getInput(resp.Meta)
 		if !ok {
 			break
 		}
@@ -156,11 +154,10 @@ func main() {
 
 	// Handle response
 	if resp.Status.Class() == gemini.StatusSuccess {
-		body, err := io.ReadAll(resp.Body)
+		_, err := io.Copy(os.Stdout, resp.Body)
 		if err != nil {
 			log.Fatal(err)
 		}
-		fmt.Print(string(body))
 	} else {
 		fmt.Printf("%d %s\n", resp.Status, resp.Meta)
 		os.Exit(1)

examples/server.go

@@ -22,11 +22,11 @@ func main() {
 		log.Fatal(err)
 	}
 
-	mux := &gemini.ServeMux{}
+	mux := &gemini.Mux{}
 	mux.Handle("/", gemini.FileServer(os.DirFS("/var/www")))
 
 	server := &gemini.Server{
-		Handler:        mux,
+		Handler:        gemini.LoggingMiddleware(mux),
 		ReadTimeout:    30 * time.Second,
 		WriteTimeout:   1 * time.Minute,
 		GetCertificate: certificates.Get,
@@ -48,7 +48,8 @@ func main() {
 	case <-c:
 		// Shutdown the server
 		log.Println("Shutting down...")
-		ctx, _ := context.WithTimeout(context.Background(), 30*time.Second)
+		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+		defer cancel()
 		err := server.Shutdown(ctx)
 		if err != nil {
 			log.Fatal(err)

examples/stream.go

@@ -21,7 +21,7 @@ func main() {
 		log.Fatal(err)
 	}
 
-	mux := &gemini.ServeMux{}
+	mux := &gemini.Mux{}
 	mux.HandleFunc("/", stream)
 
 	server := &gemini.Server{
@@ -39,33 +39,16 @@ func main() {
 
 // stream writes an infinite stream to w.
 func stream(ctx context.Context, w gemini.ResponseWriter, r *gemini.Request) {
-	ch := make(chan string)
-	ctx, cancel := context.WithCancel(ctx)
-
-	go func(ctx context.Context) {
-		for {
-			select {
-			case <-ctx.Done():
-				return
-			default:
-				ch <- fmt.Sprint(time.Now().UTC())
-			}
-			time.Sleep(time.Second)
-		}
-		// Close channel when finished.
-		// In this example this will never be reached.
-		close(ch)
-	}(ctx)
-
 	for {
-		s, ok := <-ch
-		if !ok {
-			break
+		select {
+		case <-ctx.Done():
+			return
+		default:
 		}
-		fmt.Fprintln(w, s)
+		fmt.Fprintln(w, time.Now().UTC())
 		if err := w.Flush(); err != nil {
-			cancel()
 			return
 		}
+		time.Sleep(time.Second)
 	}
 }

fs.go

@@ -1,3 +1,5 @@
+// +build go1.16
+
 package gemini
 
 import (
@@ -13,12 +15,6 @@ import (
 	"strings"
 )
 
-func init() {
-	// Add Gemini mime types
-	mime.AddExtensionType(".gmi", "text/gemini")
-	mime.AddExtensionType(".gemini", "text/gemini")
-}
-
 // FileServer returns a handler that serves Gemini requests with the contents
 // of the provided file system.
 //
@@ -65,8 +61,8 @@ func serveContent(w ResponseWriter, name string, content io.Reader) {
 //
 // As a precaution, ServeFile will reject requests where r.URL.Path contains a
 // ".." path element; this protects against callers who might unsafely use
-// filepath.Join on r.URL.Path without sanitizing it and then use that
-// filepath.Join result as the name argument.
+// path.Join on r.URL.Path without sanitizing it and then use that
+// path.Join result as the name argument.
 //
 // As another special case, ServeFile redirects any request where r.URL.Path
 // ends in "/index.gmi" to the same path, without the final "index.gmi". To
@@ -81,7 +77,7 @@ func ServeFile(w ResponseWriter, r *Request, fsys fs.FS, name string) {
 		// serveFile. Reject the request under the assumption that happened
 		// here and ".." may not be wanted.
 		// Note that name might not contain "..", for example if code (still
-		// incorrectly) used filepath.Join(myDir, r.URL.Path).
+		// incorrectly) used path.Join(myDir, r.URL.Path).
 		w.WriteHeader(StatusBadRequest, "invalid URL path")
 		return
 	}
@@ -157,7 +153,8 @@ func serveFile(w ResponseWriter, r *Request, fsys fs.FS, name string, redirect b
 		}
 
 		// Use contents of index.gmi if present
-		index, err := fsys.Open(path.Join(name, indexPage))
+		name = path.Join(name, indexPage)
+		index, err := fsys.Open(name)
 		if err == nil {
 			defer index.Close()
 			istat, err := index.Stat()

gemini.go

@@ -2,22 +2,33 @@ package gemini
 
 import (
 	"errors"
+	"mime"
 )
 
-var crlf = []byte("\r\n")
+func init() {
+	// Add Gemini mime types
+	mime.AddExtensionType(".gmi", "text/gemini")
+	mime.AddExtensionType(".gemini", "text/gemini")
+}
 
 // Errors.
 var (
 	ErrInvalidRequest  = errors.New("gemini: invalid request")
 	ErrInvalidResponse = errors.New("gemini: invalid response")
 
-	ErrCertificateExpired = errors.New("gemini: certificate expired")
-
 	// ErrBodyNotAllowed is returned by ResponseWriter.Write calls
 	// when the response status code does not permit a body.
 	ErrBodyNotAllowed = errors.New("gemini: response status code does not allow body")
-
-	// ErrHandlerTimeout is returned on ResponseWriter Write calls
-	// in handlers which have timed out.
-	ErrHandlerTimeout = errors.New("gemini: Handler timeout")
 )
+
+var crlf = []byte("\r\n")
+
+func trimCRLF(b []byte) ([]byte, bool) {
+	// Check for CR
+	if len(b) < 2 || b[len(b)-2] != '\r' {
+		return nil, false
+	}
+	// Trim CRLF
+	b = b[:len(b)-2]
+	return b, true
+}

go.mod

@@ -1,5 +1,5 @@
 module git.sr.ht/~adnano/go-gemini
 
-go 1.16
+go 1.15
 
 require golang.org/x/net v0.0.0-20210119194325-5f4716e94777

handler.go

@@ -1,9 +1,12 @@
 package gemini
 
 import (
+	"bytes"
 	"context"
+	"io"
 	"net/url"
 	"strings"
+	"time"
 )
 
 // A Handler responds to a Gemini request.
@@ -13,6 +16,9 @@ import (
 // valid to use the ResponseWriter after or concurrently with the completion
 // of the ServeGemini call.
 //
+// The provided context is canceled when the client's connection is closed
+// or the ServeGemini method returns.
+//
 // Handlers should not modify the provided Request.
 type Handler interface {
 	ServeGemini(context.Context, ResponseWriter, *Request)
@@ -31,16 +37,9 @@ func (f HandlerFunc) ServeGemini(ctx context.Context, w ResponseWriter, r *Reque
 // StatusHandler returns a request handler that responds to each request
 // with the provided status code and meta.
 func StatusHandler(status Status, meta string) Handler {
-	return &statusHandler{status, meta}
-}
-
-type statusHandler struct {
-	status Status
-	meta   string
-}
-
-func (h *statusHandler) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
-	w.WriteHeader(h.status, h.meta)
+	return HandlerFunc(func(ctx context.Context, w ResponseWriter, r *Request) {
+		w.WriteHeader(status, meta)
+	})
 }
 
 // NotFoundHandler returns a simple request handler that replies to each
@@ -75,3 +74,85 @@ func StripPrefix(prefix string, h Handler) Handler {
 		}
 	})
 }
+
+// TimeoutHandler returns a Handler that runs h with the given time limit.
+//
+// The new Handler calls h.ServeGemini to handle each request, but
+// if a call runs for longer than its time limit, the handler responds with a
+// 40 Temporary Failure status code and the given message in its response meta.
+// After such a timeout, writes by h to its ResponseWriter will return
+// context.DeadlineExceeded.
+func TimeoutHandler(h Handler, dt time.Duration, message string) Handler {
+	return &timeoutHandler{
+		h:   h,
+		dt:  dt,
+		msg: message,
+	}
+}
+
+type timeoutHandler struct {
+	h   Handler
+	dt  time.Duration
+	msg string
+}
+
+func (t *timeoutHandler) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
+	ctx, cancel := context.WithTimeout(ctx, t.dt)
+	defer cancel()
+
+	buf := &bytes.Buffer{}
+	tw := &timeoutWriter{
+		wr: &contextWriter{
+			ctx:    ctx,
+			cancel: cancel,
+			done:   ctx.Done(),
+			wc:     nopCloser{buf},
+		},
+	}
+
+	done := make(chan struct{})
+	go func() {
+		t.h.ServeGemini(ctx, tw, r)
+		close(done)
+	}()
+
+	select {
+	case <-done:
+		w.WriteHeader(tw.status, tw.meta)
+		w.Write(buf.Bytes())
+	case <-ctx.Done():
+		w.WriteHeader(StatusTemporaryFailure, t.msg)
+	}
+}
+
+type timeoutWriter struct {
+	wr          io.Writer
+	status      Status
+	meta        string
+	mediatype   string
+	wroteHeader bool
+}
+
+func (w *timeoutWriter) SetMediaType(mediatype string) {
+	w.mediatype = mediatype
+}
+
+func (w *timeoutWriter) Write(b []byte) (int, error) {
+	if !w.wroteHeader {
+		w.WriteHeader(StatusSuccess, w.mediatype)
+	}
+	return w.wr.Write(b)
+}
+
+func (w *timeoutWriter) WriteHeader(status Status, meta string) {
+	if w.wroteHeader {
+		return
+	}
+	w.status = status
+	w.meta = meta
+	w.wroteHeader = true
+}
+
+func (w *timeoutWriter) Flush() error {
+	return nil
+}

io.go

@@ -0,0 +1,76 @@
+package gemini
+
+import (
+	"context"
+	"io"
+)
+
+type contextReader struct {
+	ctx    context.Context
+	done   <-chan struct{}
+	cancel func()
+	rc     io.ReadCloser
+}
+
+func (r *contextReader) Read(p []byte) (int, error) {
+	select {
+	case <-r.done:
+		r.rc.Close()
+		return 0, r.ctx.Err()
+	default:
+	}
+	n, err := r.rc.Read(p)
+	if err != nil {
+		r.cancel()
+	}
+	return n, err
+}
+
+func (r *contextReader) Close() error {
+	r.cancel()
+	return r.rc.Close()
+}
+
+type contextWriter struct {
+	ctx    context.Context
+	done   <-chan struct{}
+	cancel func()
+	wc     io.WriteCloser
+}
+
+func (w *contextWriter) Write(b []byte) (int, error) {
+	select {
+	case <-w.done:
+		w.wc.Close()
+		return 0, w.ctx.Err()
+	default:
+	}
+	n, err := w.wc.Write(b)
+	if err != nil {
+		w.cancel()
+	}
+	return n, err
+}
+
+func (w *contextWriter) Close() error {
+	w.cancel()
+	return w.wc.Close()
+}
+
+type nopCloser struct {
+	io.Writer
+}
+
+func (nopCloser) Close() error {
+	return nil
+}
+
+type nopReadCloser struct{}
+
+func (nopReadCloser) Read(p []byte) (int, error) {
+	return 0, io.EOF
+}
+
+func (nopReadCloser) Close() error {
+	return nil
+}

middleware.go

@@ -0,0 +1,53 @@
+package gemini
+
+import (
+	"context"
+	"log"
+)
+
+// LoggingMiddleware returns a handler that wraps h and logs Gemini requests
+// and their responses to the log package's standard logger.
+// Requests are logged with the format "gemini: {host} {URL} {status code} {bytes written}".
+func LoggingMiddleware(h Handler) Handler {
+	return HandlerFunc(func(ctx context.Context, w ResponseWriter, r *Request) {
+		lw := &logResponseWriter{rw: w}
+		h.ServeGemini(ctx, lw, r)
+		host := r.ServerName()
+		log.Printf("gemini: %s %q %d %d", host, r.URL, lw.Status, lw.Wrote)
+	})
+}
+
+type logResponseWriter struct {
+	Status      Status
+	Wrote       int
+	rw          ResponseWriter
+	mediatype   string
+	wroteHeader bool
+}
+
+func (w *logResponseWriter) SetMediaType(mediatype string) {
+	w.mediatype = mediatype
+}
+
+func (w *logResponseWriter) Write(b []byte) (int, error) {
+	if !w.wroteHeader {
+		w.WriteHeader(StatusSuccess, w.mediatype)
+	}
+	n, err := w.rw.Write(b)
+	w.Wrote += n
+	return n, err
+}
+
+func (w *logResponseWriter) WriteHeader(status Status, meta string) {
+	if w.wroteHeader {
+		return
+	}
+	w.wroteHeader = true
+	w.Status = status
+	w.Wrote += len(meta) + 5
+	w.rw.WriteHeader(status, meta)
+}
+
+func (w *logResponseWriter) Flush() error {
+	return nil
+}

mux.go

@@ -10,7 +10,7 @@ import (
 	"sync"
 )
 
-// ServeMux is a Gemini request multiplexer.
+// Mux is a Gemini request multiplexer.
 // It matches the URL of each incoming request against a list of registered
 // patterns and calls the handler for the pattern that
 // most closely matches the URL.
@@ -55,17 +55,17 @@ import (
 // scheme of "gemini".
 //
 // If a subtree has been registered and a request is received naming the
-// subtree root without its trailing slash, ServeMux redirects that
+// subtree root without its trailing slash, Mux redirects that
 // request to the subtree root (adding the trailing slash). This behavior can
 // be overridden with a separate registration for the path without
-// the trailing slash. For example, registering "/images/" causes ServeMux
+// the trailing slash. For example, registering "/images/" causes Mux
 // to redirect a request for "/images" to "/images/", unless "/images" has
 // been registered separately.
 //
-// ServeMux also takes care of sanitizing the URL request path and
+// Mux also takes care of sanitizing the URL request path and
 // redirecting any request containing . or .. elements or repeated slashes
 // to an equivalent, cleaner URL.
-type ServeMux struct {
+type Mux struct {
 	mu sync.RWMutex
 	m  map[muxKey]Handler
 	es []muxEntry // slice of entries sorted from longest to shortest
@@ -106,7 +106,7 @@ func cleanPath(p string) string {
 
 // Find a handler on a handler map given a path string.
 // Most-specific (longest) pattern wins.
-func (mux *ServeMux) match(key muxKey) Handler {
+func (mux *Mux) match(key muxKey) Handler {
 	// Check for exact match first.
 	if r, ok := mux.m[key]; ok {
 		return r
@@ -134,7 +134,7 @@ func (mux *ServeMux) match(key muxKey) Handler {
 // This occurs when a handler for path + "/" was already registered, but
 // not for path itself. If the path needs appending to, it creates a new
 // URL, setting the path to u.Path + "/" and returning true to indicate so.
-func (mux *ServeMux) redirectToPathSlash(key muxKey, u *url.URL) (*url.URL, bool) {
+func (mux *Mux) redirectToPathSlash(key muxKey, u *url.URL) (*url.URL, bool) {
 	mux.mu.RLock()
 	shouldRedirect := mux.shouldRedirectRLocked(key)
 	mux.mu.RUnlock()
@@ -146,8 +146,8 @@ func (mux *ServeMux) redirectToPathSlash(key muxKey, u *url.URL) (*url.URL, bool
 
 // shouldRedirectRLocked reports whether the given path and host should be redirected to
 // path+"/". This should happen if a handler is registered for path+"/" but
-// not path -- see comments at ServeMux.
-func (mux *ServeMux) shouldRedirectRLocked(key muxKey) bool {
+// not path -- see comments at Mux.
+func (mux *Mux) shouldRedirectRLocked(key muxKey) bool {
 	if _, exist := mux.m[key]; exist {
 		return false
 	}
@@ -177,7 +177,7 @@ func getWildcard(hostname string) (string, bool) {
 // the path is not in its canonical form, the handler will be an
 // internally-generated handler that redirects to the canonical path. If the
 // host contains a port, it is ignored when matching handlers.
-func (mux *ServeMux) Handler(r *Request) Handler {
+func (mux *Mux) Handler(r *Request) Handler {
 	scheme := r.URL.Scheme
 	host := r.URL.Hostname()
 	path := cleanPath(r.URL.Path)
@@ -212,14 +212,14 @@ func (mux *ServeMux) Handler(r *Request) Handler {
 
 // ServeGemini dispatches the request to the handler whose
 // pattern most closely matches the request URL.
-func (mux *ServeMux) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
+func (mux *Mux) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
 	h := mux.Handler(r)
 	h.ServeGemini(ctx, w, r)
 }
 
 // Handle registers the handler for the given pattern.
 // If a handler already exists for pattern, Handle panics.
-func (mux *ServeMux) Handle(pattern string, handler Handler) {
+func (mux *Mux) Handle(pattern string, handler Handler) {
 	if pattern == "" {
 		panic("gemini: invalid pattern")
 	}
@@ -294,6 +294,6 @@ func appendSorted(es []muxEntry, e muxEntry) []muxEntry {
 }
 
 // HandleFunc registers the handler function for the given pattern.
-func (mux *ServeMux) HandleFunc(pattern string, handler HandlerFunc) {
+func (mux *Mux) HandleFunc(pattern string, handler HandlerFunc) {
 	mux.Handle(pattern, handler)
 }

mux_test.go

@@ -10,7 +10,7 @@ type nopHandler struct{}
 
 func (*nopHandler) ServeGemini(context.Context, ResponseWriter, *Request) {}
 
-func TestServeMuxMatch(t *testing.T) {
+func TestMuxMatch(t *testing.T) {
 	type Match struct {
 		URL string
 		Ok  bool
@@ -292,7 +292,7 @@ func TestServeMuxMatch(t *testing.T) {
 
 	for i, test := range tests {
 		h := &nopHandler{}
-		var mux ServeMux
+		var mux Mux
 		mux.Handle(test.Pattern, h)
 
 		for _, match := range tests[i].Matches {

query.go

@@ -12,7 +12,8 @@ func QueryEscape(query string) string {
 	return strings.ReplaceAll(url.PathEscape(query), "+", "%2B")
 }
 
-// QueryUnescape is identical to url.PathUnescape.
+// QueryUnescape unescapes a Gemini URL query.
+// It is identical to url.PathUnescape.
 func QueryUnescape(query string) (string, error) {
 	return url.PathUnescape(query)
 }

request.go

@@ -10,11 +10,8 @@ import (
 
 // A Request represents a Gemini request received by a server or to be sent
 // by a client.
-//
-// The field semantics differ slightly between client and server usage.
 type Request struct {
-	// URL specifies the URL being requested (for server
-	// requests) or the URL to access (for client requests).
+	// URL specifies the URL being requested.
 	URL *url.URL
 
 	// For client requests, Host optionally specifies the server to
@@ -23,9 +20,7 @@ type Request struct {
 	// For international domain names, Host may be in Punycode or
 	// Unicode form. Use golang.org/x/net/idna to convert it to
 	// either format if needed.
-	//
-	// For server requests, Host specifies the host on which the URL
-	// is sought.
+	// This field is ignored by the Gemini server.
 	Host string
 
 	// For client requests, Certificate optionally specifies the
@@ -33,24 +28,11 @@ type Request struct {
 	// This field is ignored by the Gemini server.
 	Certificate *tls.Certificate
 
-	// RemoteAddr allows Gemini servers and other software to record
-	// the network address that sent the request, usually for
-	// logging. This field is not filled in by ReadRequest.
-	// This field is ignored by the Gemini client.
-	RemoteAddr net.Addr
-
-	// TLS allows Gemini servers and other software to record
-	// information about the TLS connection on which the request
-	// was received. This field is not filled in by ReadRequest.
-	// The Gemini server in this package sets the field for
-	// TLS-enabled connections before invoking a handler;
-	// otherwise it leaves the field nil.
-	// This field is ignored by the Gemini client.
-	TLS *tls.ConnectionState
+	conn net.Conn
+	tls  *tls.ConnectionState
 }
 
 // NewRequest returns a new request.
-//
 // The returned Request is suitable for use with Client.Do.
 //
 // Callers should be careful that the URL query is properly escaped.
@@ -69,45 +51,78 @@ func NewRequest(rawurl string) (*Request, error) {
 // for specialized applications; most code should use the Server
 // to read requests and handle them via the Handler interface.
 func ReadRequest(r io.Reader) (*Request, error) {
-	// Read URL
+	// Limit request size
 	r = io.LimitReader(r, 1026)
 	br := bufio.NewReaderSize(r, 1026)
-	rawurl, err := br.ReadString('\r')
+	b, err := br.ReadBytes('\n')
 	if err != nil {
+		if err == io.EOF {
+			return nil, ErrInvalidRequest
+		}
 		return nil, err
 	}
-	// Read terminating line feed
-	if b, err := br.ReadByte(); err != nil {
-		return nil, err
-	} else if b != '\n' {
+	// Read URL
+	rawurl, ok := trimCRLF(b)
+	if !ok {
 		return nil, ErrInvalidRequest
 	}
-	// Trim carriage return
-	rawurl = rawurl[:len(rawurl)-1]
-	// Validate URL
-	if len(rawurl) > 1024 {
+	if len(rawurl) == 0 {
 		return nil, ErrInvalidRequest
 	}
-	u, err := url.Parse(rawurl)
+	u, err := url.Parse(string(rawurl))
 	if err != nil {
 		return nil, err
 	}
 	return &Request{URL: u}, nil
 }
 
-// Write writes a Gemini request in wire format.
+// WriteTo writes r to w in the Gemini request format.
 // This method consults the request URL only.
-func (r *Request) Write(w io.Writer) error {
+func (r *Request) WriteTo(w io.Writer) (int64, error) {
 	bw := bufio.NewWriterSize(w, 1026)
 	url := r.URL.String()
 	if len(url) > 1024 {
-		return ErrInvalidRequest
+		return 0, ErrInvalidRequest
 	}
-	if _, err := bw.WriteString(url); err != nil {
-		return err
+	var wrote int64
+	n, err := bw.WriteString(url)
+	wrote += int64(n)
+	if err != nil {
+		return wrote, err
 	}
-	if _, err := bw.Write(crlf); err != nil {
-		return err
+	n, err = bw.Write(crlf)
+	wrote += int64(n)
+	if err != nil {
+		return wrote, err
 	}
-	return bw.Flush()
+	return wrote, bw.Flush()
+}
+
+// Conn returns the network connection on which the request was received.
+// Conn returns nil for client requests.
+func (r *Request) Conn() net.Conn {
+	return r.conn
+}
+
+// TLS returns information about the TLS connection on which the
+// request was received.
+// TLS returns nil for client requests.
+func (r *Request) TLS() *tls.ConnectionState {
+	if r.tls == nil {
+		if tlsConn, ok := r.conn.(*tls.Conn); ok {
+			state := tlsConn.ConnectionState()
+			r.tls = &state
+		}
+	}
+	return r.tls
+}
+
+// ServerName returns the value of the TLS Server Name Indication extension
+// sent by the client.
+// ServerName returns an empty string for client requests.
+func (r *Request) ServerName() string {
+	if tls := r.TLS(); tls != nil {
+		return tls.ServerName
+	}
+	return ""
 }

request_test.go

@@ -2,7 +2,6 @@ package gemini
 
 import (
 	"bufio"
-	"io"
 	"net/url"
 	"strings"
 	"testing"
@@ -36,25 +35,25 @@ func TestReadRequest(t *testing.T) {
 		},
 		{
 			Raw: "\r\n",
-			URL: &url.URL{},
+			Err: ErrInvalidRequest,
 		},
 		{
 			Raw: "gemini://example.com\n",
-			Err: io.EOF,
+			Err: ErrInvalidRequest,
 		},
 		{
 			Raw: "gemini://example.com",
-			Err: io.EOF,
+			Err: ErrInvalidRequest,
 		},
 		{
 			// 1030 bytes
 			Raw: maxURL + "xxxxxx",
-			Err: io.EOF,
+			Err: ErrInvalidRequest,
 		},
 		{
 			// 1027 bytes
 			Raw: maxURL + "x" + "\r\n",
-			Err: io.EOF,
+			Err: ErrInvalidRequest,
 		},
 		{
 			// 1024 bytes
@@ -119,7 +118,7 @@ func TestWriteRequest(t *testing.T) {
 		t.Logf("%s", test.Req.URL)
 		var b strings.Builder
 		bw := bufio.NewWriter(&b)
-		err := test.Req.Write(bw)
+		_, err := test.Req.WriteTo(bw)
 		if err != test.Err {
 			t.Errorf("expected err = %v, got %v", test.Err, err)
 		}

response.go

@@ -5,11 +5,12 @@ import (
 	"crypto/tls"
 	"fmt"
 	"io"
+	"net"
 	"strconv"
 )
 
 // The default media type for responses.
-const defaultMediaType = "text/gemini; charset=utf-8"
+const defaultMediaType = "text/gemini"
 
 // Response represents the response from a Gemini request.
 //
@@ -17,13 +18,12 @@ const defaultMediaType = "text/gemini; charset=utf-8"
 // header has been received. The response body is streamed on demand
 // as the Body field is read.
 type Response struct {
-	// Status contains the response status code.
+	// Status is the response status code.
 	Status Status
 
-	// Meta contains more information related to the response status.
-	// For successful responses, Meta should contain the media type of the response.
-	// For failure responses, Meta should contain a short description of the failure.
-	// Meta should not be longer than 1024 bytes.
+	// Meta returns the response meta.
+	// For successful responses, the meta should contain the media type of the response.
+	// For failure responses, the meta should contain a short description of the failure.
 	Meta string
 
 	// Body represents the response body.
@@ -38,120 +38,105 @@ type Response struct {
 	// close Body.
 	Body io.ReadCloser
 
-	// TLS contains information about the TLS connection on which the
-	// response was received. It is nil for unencrypted responses.
-	TLS *tls.ConnectionState
+	conn net.Conn
 }
 
 // ReadResponse reads a Gemini response from the provided io.ReadCloser.
-func ReadResponse(rc io.ReadCloser) (*Response, error) {
+func ReadResponse(r io.ReadCloser) (*Response, error) {
 	resp := &Response{}
-	br := bufio.NewReader(rc)
 
-	// Read the status
-	statusB := make([]byte, 2)
-	if _, err := br.Read(statusB); err != nil {
+	// Limit response header size
+	lr := io.LimitReader(r, 1029)
+	// Wrap the reader to remove the limit later on
+	wr := &struct{ io.Reader }{lr}
+	br := bufio.NewReader(wr)
+
+	// Read response header
+	b, err := br.ReadBytes('\n')
+	if err != nil {
+		if err == io.EOF {
+			return nil, ErrInvalidResponse
+		}
 		return nil, err
 	}
-	status, err := strconv.Atoi(string(statusB))
+	if len(b) < 3 {
+		return nil, ErrInvalidResponse
+	}
+
+	// Read the status
+	status, err := strconv.Atoi(string(b[:2]))
 	if err != nil {
 		return nil, ErrInvalidResponse
 	}
 	resp.Status = Status(status)
 
 	// Read one space
-	if b, err := br.ReadByte(); err != nil {
-		return nil, err
-	} else if b != ' ' {
+	if b[2] != ' ' {
 		return nil, ErrInvalidResponse
 	}
 
 	// Read the meta
-	meta, err := br.ReadString('\r')
-	if err != nil {
-		return nil, err
-	}
-	// Trim carriage return
-	meta = meta[:len(meta)-1]
-	// Ensure meta is less than or equal to 1024 bytes
-	if len(meta) > 1024 {
+	meta, ok := trimCRLF(b[3:])
+	if !ok {
 		return nil, ErrInvalidResponse
 	}
-	if resp.Status.Class() == StatusSuccess && meta == "" {
-		// Use default media type
-		meta = defaultMediaType
-	}
-	resp.Meta = meta
-
-	// Read terminating newline
-	if b, err := br.ReadByte(); err != nil {
-		return nil, err
-	} else if b != '\n' {
+	if len(meta) == 0 {
 		return nil, ErrInvalidResponse
 	}
+	resp.Meta = string(meta)
 
 	if resp.Status.Class() == StatusSuccess {
-		resp.Body = newReadCloserBody(br, rc)
+		// Use unlimited reader
+		wr.Reader = r
+
+		type readCloser struct {
+			io.Reader
+			io.Closer
+		}
+		resp.Body = readCloser{br, r}
 	} else {
 		resp.Body = nopReadCloser{}
-		rc.Close()
+		r.Close()
 	}
 	return resp, nil
 }
 
-type nopReadCloser struct{}
-
-func (nopReadCloser) Read(p []byte) (int, error) {
-	return 0, io.EOF
+// Conn returns the network connection on which the response was received.
+func (r *Response) Conn() net.Conn {
+	return r.conn
 }
 
-func (nopReadCloser) Close() error {
+// TLS returns information about the TLS connection on which the
+// response was received.
+func (r *Response) TLS() *tls.ConnectionState {
+	if tlsConn, ok := r.conn.(*tls.Conn); ok {
+		state := tlsConn.ConnectionState()
+		return &state
+	}
 	return nil
 }
 
-type readCloserBody struct {
-	br *bufio.Reader // used until empty
-	io.ReadCloser
-}
-
-func newReadCloserBody(br *bufio.Reader, rc io.ReadCloser) io.ReadCloser {
-	body := &readCloserBody{ReadCloser: rc}
-	if br.Buffered() != 0 {
-		body.br = br
-	}
-	return body
-}
-
-func (b *readCloserBody) Read(p []byte) (n int, err error) {
-	if b.br != nil {
-		if n := b.br.Buffered(); len(p) > n {
-			p = p[:n]
-		}
-		n, err = b.br.Read(p)
-		if b.br.Buffered() == 0 {
-			b.br = nil
-		}
-		return n, err
-	}
-	return b.ReadCloser.Read(p)
-}
-
-// Write writes r to w in the Gemini response format, including the
+// WriteTo writes r to w in the Gemini response format, including the
 // header and body.
 //
 // This method consults the Status, Meta, and Body fields of the response.
 // The Response Body is closed after it is sent.
-func (r *Response) Write(w io.Writer) error {
-	if _, err := fmt.Fprintf(w, "%02d %s\r\n", r.Status, r.Meta); err != nil {
-		return err
+func (r *Response) WriteTo(w io.Writer) (int64, error) {
+	var wrote int64
+	n, err := fmt.Fprintf(w, "%02d %s\r\n", r.Status, r.Meta)
+	wrote += int64(n)
+	if err != nil {
+		return wrote, err
 	}
 	if r.Body != nil {
 		defer r.Body.Close()
-		if _, err := io.Copy(w, r.Body); err != nil {
-			return err
+		n, err := io.Copy(w, r.Body)
+		wrote += n
+		if err != nil {
+			return wrote, err
 		}
 	}
-	return nil
+	return wrote, nil
 }
 
 // A ResponseWriter interface is used by a Gemini handler to construct
@@ -161,19 +146,19 @@ func (r *Response) Write(w io.Writer) error {
 // has returned.
 type ResponseWriter interface {
 	// SetMediaType sets the media type that will be sent by Write for a
-	// successful response. If no media type is set, a default of
-	// "text/gemini; charset=utf-8" will be used.
+	// successful response. If no media type is set, a default media type of
+	// "text/gemini" will be used.
 	//
 	// Setting the media type after a call to Write or WriteHeader has
 	// no effect.
-	SetMediaType(string)
+	SetMediaType(mediatype string)
 
 	// Write writes the data to the connection as part of a Gemini response.
 	//
 	// If WriteHeader has not yet been called, Write calls WriteHeader with
 	// StatusSuccess and the media type set in SetMediaType before writing the data.
 	// If no media type was set, Write uses a default media type of
-	// "text/gemini; charset=utf-8".
+	// "text/gemini".
 	Write([]byte) (int, error)
 
 	// WriteHeader sends a Gemini response header with the provided
@@ -193,20 +178,15 @@ type ResponseWriter interface {
 }
 
 type responseWriter struct {
-	b           *bufio.Writer
+	bw          *bufio.Writer
 	mediatype   string
 	wroteHeader bool
 	bodyAllowed bool
 }
 
-// NewResponseWriter returns a ResponseWriter that uses the provided io.Writer.
-func NewResponseWriter(w io.Writer) ResponseWriter {
-	return newResponseWriter(w)
-}
-
 func newResponseWriter(w io.Writer) *responseWriter {
 	return &responseWriter{
-		b: bufio.NewWriter(w),
+		bw: bufio.NewWriter(w),
 	}
 }
 
@@ -226,7 +206,7 @@ func (w *responseWriter) Write(b []byte) (int, error) {
 	if !w.bodyAllowed {
 		return 0, ErrBodyNotAllowed
 	}
-	return w.b.Write(b)
+	return w.bw.Write(b)
 }
 
 func (w *responseWriter) WriteHeader(status Status, meta string) {
@@ -238,10 +218,10 @@ func (w *responseWriter) WriteHeader(status Status, meta string) {
 		w.bodyAllowed = true
 	}
 
-	w.b.WriteString(strconv.Itoa(int(status)))
-	w.b.WriteByte(' ')
-	w.b.WriteString(meta)
-	w.b.Write(crlf)
+	w.bw.WriteString(strconv.Itoa(int(status)))
+	w.bw.WriteByte(' ')
+	w.bw.WriteString(meta)
+	w.bw.Write(crlf)
 	w.wroteHeader = true
 }
 
@@ -249,6 +229,6 @@ func (w *responseWriter) Flush() error {
 	if !w.wroteHeader {
 		w.WriteHeader(StatusTemporaryFailure, "Temporary failure")
 	}
-	// Write errors from writeHeader will be returned here.
-	return w.b.Flush()
+	// Write errors from WriteHeader will be returned here.
+	return w.bw.Flush()
 }

response_test.go

@@ -2,6 +2,7 @@ package gemini
 
 import (
 	"io"
+	"io/ioutil"
 	"strings"
 	"testing"
 )
@@ -37,6 +38,15 @@ func TestReadWriteResponse(t *testing.T) {
 			Meta:      "/redirect",
 			SkipWrite: true, // skip write test since result won't match Raw
 		},
+		{
+			Raw:    "32 " + maxURL + "\r\n",
+			Status: 32,
+			Meta:   maxURL,
+		},
+		{
+			Raw: "33 " + maxURL + "xxxx" + "\r\n",
+			Err: ErrInvalidResponse,
+		},
 		{
 			Raw:    "99 Unknown status code\r\n",
 			Status: 99,
@@ -56,15 +66,15 @@ func TestReadWriteResponse(t *testing.T) {
 		},
 		{
 			Raw: "",
-			Err: io.EOF,
+			Err: ErrInvalidResponse,
 		},
 		{
 			Raw: "10 Search query",
-			Err: io.EOF,
+			Err: ErrInvalidResponse,
 		},
 		{
 			Raw: "20 text/gemini\nHello, world!",
-			Err: io.EOF,
+			Err: ErrInvalidResponse,
 		},
 		{
 			Raw: "20 text/gemini\rHello, world!",
@@ -72,7 +82,7 @@ func TestReadWriteResponse(t *testing.T) {
 		},
 		{
 			Raw: "20 text/gemini\r",
-			Err: io.EOF,
+			Err: ErrInvalidResponse,
 		},
 		{
 			Raw: "abcdefghijklmnopqrstuvwxyz",
@@ -82,11 +92,11 @@ func TestReadWriteResponse(t *testing.T) {
 
 	for _, test := range tests {
 		t.Logf("%#v", test.Raw)
-		resp, err := ReadResponse(io.NopCloser(strings.NewReader(test.Raw)))
+		resp, err := ReadResponse(ioutil.NopCloser(strings.NewReader(test.Raw)))
 		if err != test.Err {
 			t.Errorf("expected err = %v, got %v", test.Err, err)
 		}
-		if test.Err != nil {
+		if err != nil {
 			// No response
 			continue
 		}
@@ -96,7 +106,7 @@ func TestReadWriteResponse(t *testing.T) {
 		if resp.Meta != test.Meta {
 			t.Errorf("expected meta = %s, got %s", test.Meta, resp.Meta)
 		}
-		b, _ := io.ReadAll(resp.Body)
+		b, _ := ioutil.ReadAll(resp.Body)
 		body := string(b)
 		if body != test.Body {
 			t.Errorf("expected body = %#v, got %#v", test.Body, body)
@@ -107,14 +117,12 @@ func TestReadWriteResponse(t *testing.T) {
 		if test.Err != nil || test.SkipWrite {
 			continue
 		}
-		resp := &Response{
-			Status: test.Status,
-			Meta:   test.Meta,
-			Body:   io.NopCloser(strings.NewReader(test.Body)),
-		}
 
 		var b strings.Builder
-		if err := resp.Write(&b); err != nil {
+		w := newResponseWriter(nopCloser{&b})
+		w.WriteHeader(test.Status, test.Meta)
+		io.Copy(w, strings.NewReader(test.Body))
+		if err := w.Flush(); err != nil {
 			t.Error(err)
 			continue
 		}

server.go

@@ -52,7 +52,7 @@ type Server struct {
 
 	listeners map[*net.Listener]context.CancelFunc
 	conns     map[*net.Conn]context.CancelFunc
-	closed    bool // true if Closed or Shutdown called
+	closed    bool // true if Close or Shutdown called
 	shutdown  bool // true if Shutdown called
 	doneChan  chan struct{}
 	mu        sync.Mutex
@@ -229,8 +229,8 @@ func (srv *Server) deleteListener(l *net.Listener) {
 }
 
 // Serve accepts incoming connections on the Listener l, creating a new
-// service goroutine for each. The service goroutines reads the request and
-// then calls the appropriate Handler to reply to them. If the provided
+// service goroutine for each. The service goroutines read the requests and
+// then call the appropriate Handler to reply to them. If the provided
 // context expires, Serve closes l and returns the context's error.
 //
 // Serve always closes l and returns a non-nil error.
@@ -282,14 +282,17 @@ func (srv *Server) serve(ctx context.Context, l net.Listener) error {
 			return err
 		}
 		tempDelay = 0
-		go srv.ServeConn(ctx, rw)
+		go srv.serveConn(ctx, rw, false)
 	}
 }
 
-func (srv *Server) trackConn(conn *net.Conn, cancel context.CancelFunc) bool {
+func (srv *Server) trackConn(conn *net.Conn, cancel context.CancelFunc, external bool) bool {
 	srv.mu.Lock()
 	defer srv.mu.Unlock()
-	if srv.closed && !srv.shutdown {
+	// Reject the connection under the following conditions:
+	// - Shutdown or Close has been called and conn is external (from ServeConn)
+	// - Close (not Shutdown) has been called and conn is internal (from Serve)
+	if srv.closed && (external || !srv.shutdown) {
 		return false
 	}
 	if srv.conns == nil {
@@ -309,15 +312,17 @@ func (srv *Server) deleteConn(conn *net.Conn) {
 // It closes the connection when the response has been completed.
 // If the provided context expires before the response has completed,
 // ServeConn closes the connection and returns the context's error.
-//
-// Note that ServeConn can be used during a Shutdown.
 func (srv *Server) ServeConn(ctx context.Context, conn net.Conn) error {
+	return srv.serveConn(ctx, conn, true)
+}
+
+func (srv *Server) serveConn(ctx context.Context, conn net.Conn, external bool) error {
 	defer conn.Close()
 
 	ctx, cancel := context.WithCancel(ctx)
 	defer cancel()
 
-	if !srv.trackConn(&conn, cancel) {
+	if !srv.trackConn(&conn, cancel, external) {
 		return context.Canceled
 	}
 	defer srv.tryCloseDone()
@@ -332,7 +337,7 @@ func (srv *Server) ServeConn(ctx context.Context, conn net.Conn) error {
 
 	errch := make(chan error, 1)
 	go func() {
-		errch <- srv.serveConn(ctx, conn)
+		errch <- srv.goServeConn(ctx, conn)
 	}()
 
 	select {
@@ -343,24 +348,30 @@ func (srv *Server) ServeConn(ctx context.Context, conn net.Conn) error {
 	}
 }
 
-func (srv *Server) serveConn(ctx context.Context, conn net.Conn) error {
-	w := newResponseWriter(conn)
+func (srv *Server) goServeConn(ctx context.Context, conn net.Conn) error {
+	ctx, cancel := context.WithCancel(ctx)
+	done := ctx.Done()
+	cw := &contextWriter{
+		ctx:    ctx,
+		done:   done,
+		cancel: cancel,
+		wc:     conn,
+	}
+	r := &contextReader{
+		ctx:    ctx,
+		done:   done,
+		cancel: cancel,
+		rc:     conn,
+	}
 
-	req, err := ReadRequest(conn)
+	w := newResponseWriter(cw)
+
+	req, err := ReadRequest(r)
 	if err != nil {
 		w.WriteHeader(StatusBadRequest, "Bad request")
 		return w.Flush()
 	}
-
-	// Store the TLS connection state
-	if tlsConn, ok := conn.(*tls.Conn); ok {
-		state := tlsConn.ConnectionState()
-		req.TLS = &state
-		req.Host = state.ServerName
-	}
-
-	// Store remote address
-	req.RemoteAddr = conn.RemoteAddr()
+	req.conn = conn
 
 	h := srv.Handler
 	if h == nil {

timeout.go

@@ -1,112 +0,0 @@
-package gemini
-
-import (
-	"bytes"
-	"context"
-	"sync"
-	"time"
-)
-
-// TimeoutHandler returns a Handler that runs h with the given time limit.
-//
-// The new Handler calls h.ServeGemini to handle each request, but
-// if a call runs for longer than its time limit, the handler responds with a
-// 40 Temporary Failure error. After such a timeout, writes by h to its
-// ResponseWriter will return ErrHandlerTimeout.
-func TimeoutHandler(h Handler, dt time.Duration) Handler {
-	return &timeoutHandler{
-		h:  h,
-		dt: dt,
-	}
-}
-
-type timeoutHandler struct {
-	h  Handler
-	dt time.Duration
-}
-
-func (t *timeoutHandler) ServeGemini(ctx context.Context, w ResponseWriter, r *Request) {
-	ctx, cancel := context.WithTimeout(ctx, t.dt)
-	defer cancel()
-
-	done := make(chan struct{})
-	tw := &timeoutWriter{}
-	panicChan := make(chan interface{}, 1)
-	go func() {
-		defer func() {
-			if p := recover(); p != nil {
-				panicChan <- p
-			}
-		}()
-		t.h.ServeGemini(ctx, tw, r)
-		close(done)
-	}()
-
-	select {
-	case p := <-panicChan:
-		panic(p)
-	case <-done:
-		tw.mu.Lock()
-		defer tw.mu.Unlock()
-		if !tw.wroteHeader {
-			tw.status = StatusSuccess
-		}
-		w.WriteHeader(tw.status, tw.meta)
-		w.Write(tw.b.Bytes())
-	case <-ctx.Done():
-		tw.mu.Lock()
-		defer tw.mu.Unlock()
-		w.WriteHeader(StatusTemporaryFailure, "Timeout")
-		tw.timedOut = true
-	}
-}
-
-type timeoutWriter struct {
-	mu          sync.Mutex
-	b           bytes.Buffer
-	status      Status
-	meta        string
-	mediatype   string
-	wroteHeader bool
-	timedOut    bool
-}
-
-func (w *timeoutWriter) SetMediaType(mediatype string) {
-	w.mu.Lock()
-	defer w.mu.Unlock()
-	w.mediatype = mediatype
-}
-
-func (w *timeoutWriter) Write(b []byte) (int, error) {
-	w.mu.Lock()
-	defer w.mu.Unlock()
-	if w.timedOut {
-		return 0, ErrHandlerTimeout
-	}
-	if !w.wroteHeader {
-		w.writeHeaderLocked(StatusSuccess, w.mediatype)
-	}
-	return w.b.Write(b)
-}
-
-func (w *timeoutWriter) WriteHeader(status Status, meta string) {
-	w.mu.Lock()
-	defer w.mu.Unlock()
-	if w.timedOut {
-		return
-	}
-	w.writeHeaderLocked(status, meta)
-}
-
-func (w *timeoutWriter) writeHeaderLocked(status Status, meta string) {
-	if w.wroteHeader {
-		return
-	}
-	w.status = status
-	w.meta = meta
-	w.wroteHeader = true
-}
-
-func (w *timeoutWriter) Flush() error {
-	return nil
-}

tofu/tofu.go

@@ -4,17 +4,16 @@ package tofu
 import (
 	"bufio"
 	"bytes"
-	"crypto/sha512"
+	"crypto/sha256"
 	"crypto/x509"
-	"errors"
+	"encoding/base64"
 	"fmt"
 	"io"
 	"os"
+	"path/filepath"
 	"sort"
-	"strconv"
 	"strings"
 	"sync"
-	"time"
 )
 
 // KnownHosts represents a list of known hosts.
@@ -84,7 +83,11 @@ func (k *KnownHosts) WriteTo(w io.Writer) (int64, error) {
 
 // Load loads the known hosts entries from the provided path.
 func (k *KnownHosts) Load(path string) error {
-	f, err := os.Open(path)
+	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
+		return err
+	}
+
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_RDONLY, 0644)
 	if err != nil {
 		return err
 	}
@@ -133,6 +136,9 @@ func (k *KnownHosts) Parse(r io.Reader) error {
 		if err != nil {
 			continue
 		}
+		if h.Algorithm != "sha256" {
+			continue
+		}
 
 		k.hosts[h.Hostname] = h
 	}
@@ -143,22 +149,17 @@ func (k *KnownHosts) Parse(r io.Reader) error {
 // TOFU implements basic trust on first use.
 //
 // If the host is not on file, it is added to the list.
-// If the host on file is expired, a new entry is added to the list.
 // If the fingerprint does not match the one on file, an error is returned.
 func (k *KnownHosts) TOFU(hostname string, cert *x509.Certificate) error {
-	host := NewHost(hostname, cert.Raw, cert.NotAfter)
-
+	host := NewHost(hostname, cert.Raw)
 	knownHost, ok := k.Lookup(hostname)
-	if !ok || time.Now().After(knownHost.Expires) {
+	if !ok {
 		k.Add(host)
 		return nil
 	}
-
-	// Check fingerprint
-	if !bytes.Equal(knownHost.Fingerprint, host.Fingerprint) {
+	if host.Fingerprint != knownHost.Fingerprint {
 		return fmt.Errorf("fingerprint for %q does not match", hostname)
 	}
-
 	return nil
 }
 
@@ -266,21 +267,16 @@ func (p *PersistentHosts) Entries() []Host {
 // TOFU implements trust on first use with a persistent set of known hosts.
 //
 // If the host is not on file, it is added to the list.
-// If the host on file is expired, a new entry is added to the list.
 // If the fingerprint does not match the one on file, an error is returned.
 func (p *PersistentHosts) TOFU(hostname string, cert *x509.Certificate) error {
-	host := NewHost(hostname, cert.Raw, cert.NotAfter)
-
+	host := NewHost(hostname, cert.Raw)
 	knownHost, ok := p.Lookup(hostname)
-	if !ok || time.Now().After(knownHost.Expires) {
+	if !ok {
 		return p.Add(host)
 	}
-
-	// Check fingerprint
-	if !bytes.Equal(knownHost.Fingerprint, host.Fingerprint) {
+	if host.Fingerprint != knownHost.Fingerprint {
 		return fmt.Errorf("fingerprint for %q does not match", hostname)
 	}
-
 	return nil
 }
 
@@ -291,22 +287,20 @@ func (p *PersistentHosts) Close() error {
 
 // Host represents a host entry with a fingerprint using a certain algorithm.
 type Host struct {
-	Hostname    string      // hostname
-	Algorithm   string      // fingerprint algorithm e.g. SHA-512
-	Fingerprint Fingerprint // fingerprint
-	Expires     time.Time   // unix time of the fingerprint expiration date
+	Hostname    string // hostname
+	Algorithm   string // fingerprint algorithm e.g. sha256
+	Fingerprint string // fingerprint
 }
 
-// NewHost returns a new host with a SHA-512 fingerprint of
+// NewHost returns a new host with a SHA256 fingerprint of
 // the provided raw data.
-func NewHost(hostname string, raw []byte, expires time.Time) Host {
-	sum := sha512.Sum512(raw)
+func NewHost(hostname string, raw []byte) Host {
+	sum := sha256.Sum256(raw)
 
 	return Host{
 		Hostname:    hostname,
-		Algorithm:   "SHA-512",
-		Fingerprint: sum[:],
-		Expires:     expires,
+		Algorithm:   "sha256",
+		Fingerprint: base64.StdEncoding.EncodeToString(sum[:]),
 	}
 }
 
@@ -324,95 +318,19 @@ func (h Host) String() string {
 	b.WriteByte(' ')
 	b.WriteString(h.Algorithm)
 	b.WriteByte(' ')
-	b.WriteString(h.Fingerprint.String())
-	b.WriteByte(' ')
-	b.WriteString(strconv.FormatInt(h.Expires.Unix(), 10))
+	b.WriteString(h.Fingerprint)
 	return b.String()
 }
 
 // UnmarshalText unmarshals the host from the provided text.
 func (h *Host) UnmarshalText(text []byte) error {
-	const format = "hostname algorithm hex-fingerprint expiry-unix-ts"
-
 	parts := bytes.Split(text, []byte(" "))
-	if len(parts) != 4 {
-		return fmt.Errorf("expected the format %q", format)
-	}
-
-	if len(parts[0]) == 0 {
-		return errors.New("empty hostname")
+	if len(parts) != 3 {
+		return fmt.Errorf("expected the format 'hostname algorithm fingerprint'")
 	}
 
 	h.Hostname = string(parts[0])
-
-	algorithm := string(parts[1])
-	if algorithm != "SHA-512" {
-		return fmt.Errorf("unsupported algorithm %q", algorithm)
-	}
-
-	h.Algorithm = algorithm
-
-	fingerprint := make([]byte, 0, sha512.Size)
-	scanner := bufio.NewScanner(bytes.NewReader(parts[2]))
-	scanner.Split(scanFingerprint)
-
-	for scanner.Scan() {
-		b, err := strconv.ParseUint(scanner.Text(), 16, 8)
-		if err != nil {
-			return fmt.Errorf("failed to parse fingerprint hash: %w", err)
-		}
-		fingerprint = append(fingerprint, byte(b))
-	}
-
-	if len(fingerprint) != sha512.Size {
-		return fmt.Errorf("invalid fingerprint size %d, expected %d",
-			len(fingerprint), sha512.Size)
-	}
-
-	h.Fingerprint = fingerprint
-
-	unix, err := strconv.ParseInt(string(parts[3]), 10, 0)
-	if err != nil {
-		return fmt.Errorf("invalid unix timestamp: %w", err)
-	}
-
-	h.Expires = time.Unix(unix, 0)
-
+	h.Algorithm = string(parts[1])
+	h.Fingerprint = string(parts[2])
 	return nil
 }
-
-func scanFingerprint(data []byte, atEOF bool) (advance int, token []byte, err error) {
-	if atEOF && len(data) == 0 {
-		return 0, nil, nil
-	}
-	if i := bytes.IndexByte(data, ':'); i >= 0 {
-		// We have a full newline-terminated line.
-		return i + 1, data[0:i], nil
-	}
-
-	// If we're at EOF, we have a final, non-terminated hex byte
-	if atEOF {
-		return len(data), data, nil
-	}
-
-	// Request more data.
-	return 0, nil, nil
-}
-
-// Fingerprint represents a fingerprint.
-type Fingerprint []byte
-
-// String returns a string representation of the fingerprint.
-func (f Fingerprint) String() string {
-	var sb strings.Builder
-
-	for i, b := range f {
-		if i > 0 {
-			sb.WriteByte(':')
-		}
-
-		fmt.Fprintf(&sb, "%02X", b)
-	}
-
-	return sb.String()
-}

vendor.go

@@ -1,212 +0,0 @@
-// Hostname verification code from the crypto/x509 package.
-// Modified to allow Common Names in the short term, until new certificates
-// can be issued with SANs.
-
-// Copyright 2011 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package gemini
-
-import (
-	"crypto/x509"
-	"net"
-	"strings"
-	"unicode/utf8"
-)
-
-var oidExtensionSubjectAltName = []int{2, 5, 29, 17}
-
-func hasSANExtension(c *x509.Certificate) bool {
-	for _, e := range c.Extensions {
-		if e.Id.Equal(oidExtensionSubjectAltName) {
-			return true
-		}
-	}
-	return false
-}
-
-func validHostnamePattern(host string) bool { return validHostname(host, true) }
-func validHostnameInput(host string) bool   { return validHostname(host, false) }
-
-// validHostname reports whether host is a valid hostname that can be matched or
-// matched against according to RFC 6125 2.2, with some leniency to accommodate
-// legacy values.
-func validHostname(host string, isPattern bool) bool {
-	if !isPattern {
-		host = strings.TrimSuffix(host, ".")
-	}
-	if len(host) == 0 {
-		return false
-	}
-
-	for i, part := range strings.Split(host, ".") {
-		if part == "" {
-			// Empty label.
-			return false
-		}
-		if isPattern && i == 0 && part == "*" {
-			// Only allow full left-most wildcards, as those are the only ones
-			// we match, and matching literal '*' characters is probably never
-			// the expected behavior.
-			continue
-		}
-		for j, c := range part {
-			if 'a' <= c && c <= 'z' {
-				continue
-			}
-			if '0' <= c && c <= '9' {
-				continue
-			}
-			if 'A' <= c && c <= 'Z' {
-				continue
-			}
-			if c == '-' && j != 0 {
-				continue
-			}
-			if c == '_' {
-				// Not a valid character in hostnames, but commonly
-				// found in deployments outside the WebPKI.
-				continue
-			}
-			return false
-		}
-	}
-
-	return true
-}
-
-// commonNameAsHostname reports whether the Common Name field should be
-// considered the hostname that the certificate is valid for. This is a legacy
-// behavior, disabled by default or if the Subject Alt Name extension is present.
-//
-// It applies the strict validHostname check to the Common Name field, so that
-// certificates without SANs can still be validated against CAs with name
-// constraints if there is no risk the CN would be matched as a hostname.
-// See NameConstraintsWithoutSANs and issue 24151.
-func commonNameAsHostname(c *x509.Certificate) bool {
-	return !hasSANExtension(c) && validHostnamePattern(c.Subject.CommonName)
-}
-
-func matchExactly(hostA, hostB string) bool {
-	if hostA == "" || hostA == "." || hostB == "" || hostB == "." {
-		return false
-	}
-	return toLowerCaseASCII(hostA) == toLowerCaseASCII(hostB)
-}
-
-func matchHostnames(pattern, host string) bool {
-	pattern = toLowerCaseASCII(pattern)
-	host = toLowerCaseASCII(strings.TrimSuffix(host, "."))
-
-	if len(pattern) == 0 || len(host) == 0 {
-		return false
-	}
-
-	patternParts := strings.Split(pattern, ".")
-	hostParts := strings.Split(host, ".")
-
-	if len(patternParts) != len(hostParts) {
-		return false
-	}
-
-	for i, patternPart := range patternParts {
-		if i == 0 && patternPart == "*" {
-			continue
-		}
-		if patternPart != hostParts[i] {
-			return false
-		}
-	}
-
-	return true
-}
-
-// toLowerCaseASCII returns a lower-case version of in. See RFC 6125 6.4.1. We use
-// an explicitly ASCII function to avoid any sharp corners resulting from
-// performing Unicode operations on DNS labels.
-func toLowerCaseASCII(in string) string {
-	// If the string is already lower-case then there's nothing to do.
-	isAlreadyLowerCase := true
-	for _, c := range in {
-		if c == utf8.RuneError {
-			// If we get a UTF-8 error then there might be
-			// upper-case ASCII bytes in the invalid sequence.
-			isAlreadyLowerCase = false
-			break
-		}
-		if 'A' <= c && c <= 'Z' {
-			isAlreadyLowerCase = false
-			break
-		}
-	}
-
-	if isAlreadyLowerCase {
-		return in
-	}
-
-	out := []byte(in)
-	for i, c := range out {
-		if 'A' <= c && c <= 'Z' {
-			out[i] += 'a' - 'A'
-		}
-	}
-	return string(out)
-}
-
-// verifyHostname returns nil if c is a valid certificate for the named host.
-// Otherwise it returns an error describing the mismatch.
-//
-// IP addresses can be optionally enclosed in square brackets and are checked
-// against the IPAddresses field. Other names are checked case insensitively
-// against the DNSNames field. If the names are valid hostnames, the certificate
-// fields can have a wildcard as the left-most label.
-//
-// The legacy Common Name field is ignored unless it's a valid hostname, the
-// certificate doesn't have any Subject Alternative Names, and the GODEBUG
-// environment variable is set to "x509ignoreCN=0". Support for Common Name is
-// deprecated will be entirely removed in the future.
-func verifyHostname(c *x509.Certificate, h string) error {
-	// IP addresses may be written in [ ].
-	candidateIP := h
-	if len(h) >= 3 && h[0] == '[' && h[len(h)-1] == ']' {
-		candidateIP = h[1 : len(h)-1]
-	}
-	if ip := net.ParseIP(candidateIP); ip != nil {
-		// We only match IP addresses against IP SANs.
-		// See RFC 6125, Appendix B.2.
-		for _, candidate := range c.IPAddresses {
-			if ip.Equal(candidate) {
-				return nil
-			}
-		}
-		return x509.HostnameError{c, candidateIP}
-	}
-
-	names := c.DNSNames
-	if commonNameAsHostname(c) {
-		names = []string{c.Subject.CommonName}
-	}
-
-	candidateName := toLowerCaseASCII(h) // Save allocations inside the loop.
-	validCandidateName := validHostnameInput(candidateName)
-
-	for _, match := range names {
-		// Ideally, we'd only match valid hostnames according to RFC 6125 like
-		// browsers (more or less) do, but in practice Go is used in a wider
-		// array of contexts and can't even assume DNS resolution. Instead,
-		// always allow perfect matches, and only apply wildcard and trailing
-		// dot processing to valid hostnames.
-		if validCandidateName && validHostnamePattern(match) {
-			if matchHostnames(match, candidateName) {
-				return nil
-			}
-		} else {
-			if matchExactly(match, candidateName) {
-				return nil
-			}
-		}
-	}
-
-	return x509.HostnameError{c, h}
-}