Update vendor

9 files changed, 275 insertions, 134 deletions

diff --git a/vendor/golang.org/x/net/http2/Dockerfile b/vendor/golang.org/x/net/http2/Dockerfile
index 53fc5257..85122459 100644
--- a/vendor/golang.org/x/net/http2/Dockerfile
+++ b/vendor/golang.org/x/net/http2/Dockerfile
@@ -38,7 +38,7 @@ RUN make
 RUN make install
 
 WORKDIR /root
-RUN wget http://curl.haxx.se/download/curl-7.45.0.tar.gz
+RUN wget https://curl.se/download/curl-7.45.0.tar.gz
 RUN tar -zxvf curl-7.45.0.tar.gz
 WORKDIR /root/curl-7.45.0
 RUN ./configure --with-ssl --with-nghttp2=/usr/local
diff --git a/vendor/golang.org/x/net/http2/ascii.go b/vendor/golang.org/x/net/http2/ascii.go
new file mode 100644
index 00000000..17caa205
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/ascii.go
@@ -0,0 +1,53 @@
+// Copyright 2021 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 http2
+
+import "strings"
+
+// The HTTP protocols are defined in terms of ASCII, not Unicode. This file
+// contains helper functions which may use Unicode-aware functions which would
+// otherwise be unsafe and could introduce vulnerabilities if used improperly.
+
+// asciiEqualFold is strings.EqualFold, ASCII only. It reports whether s and t
+// are equal, ASCII-case-insensitively.
+func asciiEqualFold(s, t string) bool {
+	if len(s) != len(t) {
+		return false
+	}
+	for i := 0; i < len(s); i++ {
+		if lower(s[i]) != lower(t[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// lower returns the ASCII lowercase version of b.
+func lower(b byte) byte {
+	if 'A' <= b && b <= 'Z' {
+		return b + ('a' - 'A')
+	}
+	return b
+}
+
+// isASCIIPrint returns whether s is ASCII and printable according to
+// https://tools.ietf.org/html/rfc20#section-4.2.
+func isASCIIPrint(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] < ' ' || s[i] > '~' {
+			return false
+		}
+	}
+	return true
+}
+
+// asciiToLower returns the lowercase version of s if s is ASCII and printable,
+// and whether or not it was.
+func asciiToLower(s string) (lower string, ok bool) {
+	if !isASCIIPrint(s) {
+		return "", false
+	}
+	return strings.ToLower(s), true
+}
diff --git a/vendor/golang.org/x/net/http2/client_conn_pool.go b/vendor/golang.org/x/net/http2/client_conn_pool.go
index 3a67636f..652bc11a 100644
--- a/vendor/golang.org/x/net/http2/client_conn_pool.go
+++ b/vendor/golang.org/x/net/http2/client_conn_pool.go
@@ -7,7 +7,9 @@
 package http2
 
 import (
+	"context"
 	"crypto/tls"
+	"errors"
 	"net/http"
 	"sync"
 )
@@ -78,61 +80,69 @@ func (p *clientConnPool) getClientConn(req *http.Request, addr string, dialOnMis
 		// It gets its own connection.
 		traceGetConn(req, addr)
 		const singleUse = true
-		cc, err := p.t.dialClientConn(addr, singleUse)
+		cc, err := p.t.dialClientConn(req.Context(), addr, singleUse)
 		if err != nil {
 			return nil, err
 		}
 		return cc, nil
 	}
-	p.mu.Lock()
-	for _, cc := range p.conns[addr] {
-		if st := cc.idleState(); st.canTakeNewRequest {
-			if p.shouldTraceGetConn(st) {
-				traceGetConn(req, addr)
+	for {
+		p.mu.Lock()
+		for _, cc := range p.conns[addr] {
+			if st := cc.idleState(); st.canTakeNewRequest {
+				if p.shouldTraceGetConn(st) {
+					traceGetConn(req, addr)
+				}
+				p.mu.Unlock()
+				return cc, nil
 			}
+		}
+		if !dialOnMiss {
 			p.mu.Unlock()
-			return cc, nil
+			return nil, ErrNoCachedConn
 		}
-	}
-	if !dialOnMiss {
+		traceGetConn(req, addr)
+		call := p.getStartDialLocked(req.Context(), addr)
 		p.mu.Unlock()
-		return nil, ErrNoCachedConn
+		<-call.done
+		if shouldRetryDial(call, req) {
+			continue
+		}
+		return call.res, call.err
 	}
-	traceGetConn(req, addr)
-	call := p.getStartDialLocked(addr)
-	p.mu.Unlock()
-	<-call.done
-	return call.res, call.err
 }
 
 // dialCall is an in-flight Transport dial call to a host.
 type dialCall struct {
-	_    incomparable
-	p    *clientConnPool
+	_ incomparable
+	p *clientConnPool
+	// the context associated with the request
+	// that created this dialCall
+	ctx  context.Context
 	done chan struct{} // closed when done
 	res  *ClientConn   // valid after done is closed
 	err  error         // valid after done is closed
 }
 
 // requires p.mu is held.
-func (p *clientConnPool) getStartDialLocked(addr string) *dialCall {
+func (p *clientConnPool) getStartDialLocked(ctx context.Context, addr string) *dialCall {
 	if call, ok := p.dialing[addr]; ok {
 		// A dial is already in-flight. Don't start another.
 		return call
 	}
-	call := &dialCall{p: p, done: make(chan struct{})}
+	call := &dialCall{p: p, done: make(chan struct{}), ctx: ctx}
 	if p.dialing == nil {
 		p.dialing = make(map[string]*dialCall)
 	}
 	p.dialing[addr] = call
-	go call.dial(addr)
+	go call.dial(call.ctx, addr)
 	return call
 }
 
 // run in its own goroutine.
-func (c *dialCall) dial(addr string) {
+func (c *dialCall) dial(ctx context.Context, addr string) {
 	const singleUse = false // shared conn
-	c.res, c.err = c.p.t.dialClientConn(addr, singleUse)
+	c.res, c.err = c.p.t.dialClientConn(ctx, addr, singleUse)
 	close(c.done)
 
 	c.p.mu.Lock()
@@ -276,3 +286,28 @@ type noDialClientConnPool struct{ *clientConnPool }
 func (p noDialClientConnPool) GetClientConn(req *http.Request, addr string) (*ClientConn, error) {
 	return p.getClientConn(req, addr, noDialOnMiss)
 }
+
+// shouldRetryDial reports whether the current request should
+// retry dialing after the call finished unsuccessfully, for example
+// if the dial was canceled because of a context cancellation or
+// deadline expiry.
+func shouldRetryDial(call *dialCall, req *http.Request) bool {
+	if call.err == nil {
+		// No error, no need to retry
+		return false
+	}
+	if call.ctx == req.Context() {
+		// If the call has the same context as the request, the dial
+		// should not be retried, since any cancellation will have come
+		// from this request.
+		return false
+	}
+	if !errors.Is(call.err, context.Canceled) && !errors.Is(call.err, context.DeadlineExceeded) {
+		// If the call error is not because of a context cancellation or a deadline expiry,
+		// the dial should not be retried.
+		return false
+	}
+	// Only retry if the error is a context cancellation error or deadline expiry
+	// and the context associated with the call was canceled or expired.
+	return call.ctx.Err() != nil
+}
diff --git a/vendor/golang.org/x/net/http2/go115.go b/vendor/golang.org/x/net/http2/go115.go
new file mode 100644
index 00000000..908af1ab
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/go115.go
@@ -0,0 +1,27 @@
+// Copyright 2021 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.
+
+//go:build go1.15
+// +build go1.15
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+)
+
+// dialTLSWithContext uses tls.Dialer, added in Go 1.15, to open a TLS
+// connection.
+func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	dialer := &tls.Dialer{
+		Config: cfg,
+	}
+	cn, err := dialer.DialContext(ctx, network, addr)
+	if err != nil {
+		return nil, err
+	}
+	tlsCn := cn.(*tls.Conn) // DialContext comment promises this will always succeed
+	return tlsCn, nil
+}
diff --git a/vendor/golang.org/x/net/http2/headermap.go b/vendor/golang.org/x/net/http2/headermap.go
index c3ff3fa1..9e12941d 100644
--- a/vendor/golang.org/x/net/http2/headermap.go
+++ b/vendor/golang.org/x/net/http2/headermap.go
@@ -6,7 +6,6 @@ package http2
 
 import (
 	"net/http"
-	"strings"
 	"sync"
 )
 
@@ -79,10 +78,10 @@ func buildCommonHeaderMaps() {
 	}
 }
 
-func lowerHeader(v string) string {
+func lowerHeader(v string) (lower string, ascii bool) {
 	buildCommonHeaderMapsOnce()
 	if s, ok := commonLowerHeader[v]; ok {
-		return s
+		return s, true
 	}
-	return strings.ToLower(v)
+	return asciiToLower(v)
 }
diff --git a/vendor/golang.org/x/net/http2/not_go115.go b/vendor/golang.org/x/net/http2/not_go115.go
new file mode 100644
index 00000000..e6c04cf7
--- /dev/null
+++ b/vendor/golang.org/x/net/http2/not_go115.go
@@ -0,0 +1,31 @@
+// Copyright 2021 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.
+
+//go:build !go1.15
+// +build !go1.15
+
+package http2
+
+import (
+	"context"
+	"crypto/tls"
+)
+
+// dialTLSWithContext opens a TLS connection.
+func (t *Transport) dialTLSWithContext(ctx context.Context, network, addr string, cfg *tls.Config) (*tls.Conn, error) {
+	cn, err := tls.Dial(network, addr, cfg)
+	if err != nil {
+		return nil, err
+	}
+	if err := cn.Handshake(); err != nil {
+		return nil, err
+	}
+	if cfg.InsecureSkipVerify {
+		return cn, nil
+	}
+	if err := cn.VerifyHostname(cfg.ServerName); err != nil {
+		return nil, err
+	}
+	return cn, nil
+}
diff --git a/vendor/golang.org/x/net/http2/server.go b/vendor/golang.org/x/net/http2/server.go
index e125bbd2..0ccbe9b4 100644
--- a/vendor/golang.org/x/net/http2/server.go
+++ b/vendor/golang.org/x/net/http2/server.go
@@ -231,13 +231,12 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 
 	if s.TLSConfig == nil {
 		s.TLSConfig = new(tls.Config)
-	} else if s.TLSConfig.CipherSuites != nil {
-		// If they already provided a CipherSuite list, return
-		// an error if it has a bad order or is missing
-		// ECDHE_RSA_WITH_AES_128_GCM_SHA256 or ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
+	} else if s.TLSConfig.CipherSuites != nil && s.TLSConfig.MinVersion < tls.VersionTLS13 {
+		// If they already provided a TLS 1.0–1.2 CipherSuite list, return an
+		// error if it is missing ECDHE_RSA_WITH_AES_128_GCM_SHA256 or
+		// ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
 		haveRequired := false
-		sawBad := false
-		for i, cs := range s.TLSConfig.CipherSuites {
+		for _, cs := range s.TLSConfig.CipherSuites {
 			switch cs {
 			case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
 				// Alternative MTI cipher to not discourage ECDSA-only servers.
@@ -245,14 +244,9 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 				tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
 				haveRequired = true
 			}
-			if isBadCipher(cs) {
-				sawBad = true
-			} else if sawBad {
-				return fmt.Errorf("http2: TLSConfig.CipherSuites index %d contains an HTTP/2-approved cipher suite (%#04x), but it comes after unapproved cipher suites. With this configuration, clients that don't support previous, approved cipher suites may be given an unapproved one and reject the connection.", i, cs)
-			}
 		}
 		if !haveRequired {
-			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256).")
+			return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher (need at least one of TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 or TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256)")
 		}
 	}
 
@@ -265,16 +259,12 @@ func ConfigureServer(s *http.Server, conf *Server) error {
 
 	s.TLSConfig.PreferServerCipherSuites = true
 
-	haveNPN := false
-	for _, p := range s.TLSConfig.NextProtos {
-		if p == NextProtoTLS {
-			haveNPN = true
-			break
-		}
-	}
-	if !haveNPN {
+	if !strSliceContains(s.TLSConfig.NextProtos, NextProtoTLS) {
 		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, NextProtoTLS)
 	}
+	if !strSliceContains(s.TLSConfig.NextProtos, "http/1.1") {
+		s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, "http/1.1")
+	}
 
 	if s.TLSNextProto == nil {
 		s.TLSNextProto = map[string]func(*http.Server, *tls.Conn, http.Handler){}
@@ -2789,8 +2779,12 @@ func (w *responseWriter) Push(target string, opts *http.PushOptions) error {
 		// but PUSH_PROMISE requests cannot have a body.
 		// http://tools.ietf.org/html/rfc7540#section-8.2
 		// Also disallow Host, since the promised URL must be absolute.
-		switch strings.ToLower(k) {
-		case "content-length", "content-encoding", "trailer", "te", "expect", "host":
+		if asciiEqualFold(k, "content-length") ||
+			asciiEqualFold(k, "content-encoding") ||
+			asciiEqualFold(k, "trailer") ||
+			asciiEqualFold(k, "te") ||
+			asciiEqualFold(k, "expect") ||
+			asciiEqualFold(k, "host") {
 			return fmt.Errorf("promised request headers cannot include %q", k)
 		}
 	}
diff --git a/vendor/golang.org/x/net/http2/transport.go b/vendor/golang.org/x/net/http2/transport.go
index 7688d72c..b97adff7 100644
--- a/vendor/golang.org/x/net/http2/transport.go
+++ b/vendor/golang.org/x/net/http2/transport.go
@@ -264,9 +264,8 @@ type ClientConn struct {
 	peerMaxHeaderListSize uint64
 	initialWindowSize     uint32
 
-	hbuf    bytes.Buffer // HPACK encoder writes into this
-	henc    *hpack.Encoder
-	freeBuf [][]byte
+	hbuf bytes.Buffer // HPACK encoder writes into this
+	henc *hpack.Encoder
 
 	wmu  sync.Mutex // held while writing; acquire AFTER mu if holding both
 	werr error      // first write error that has occurred
@@ -564,12 +563,12 @@ func canRetryError(err error) bool {
 	return false
 }
 
-func (t *Transport) dialClientConn(addr string, singleUse bool) (*ClientConn, error) {
+func (t *Transport) dialClientConn(ctx context.Context, addr string, singleUse bool) (*ClientConn, error) {
 	host, _, err := net.SplitHostPort(addr)
 	if err != nil {
 		return nil, err
 	}
-	tconn, err := t.dialTLS()("tcp", addr, t.newTLSConfig(host))
+	tconn, err := t.dialTLS(ctx)("tcp", addr, t.newTLSConfig(host))
 	if err != nil {
 		return nil, err
 	}
@@ -590,34 +589,24 @@ func (t *Transport) newTLSConfig(host string) *tls.Config {
 	return cfg
 }
 
-func (t *Transport) dialTLS() func(string, string, *tls.Config) (net.Conn, error) {
+func (t *Transport) dialTLS(ctx context.Context) func(string, string, *tls.Config) (net.Conn, error) {
 	if t.DialTLS != nil {
 		return t.DialTLS
 	}
-	return t.dialTLSDefault
-}
-
-func (t *Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.Conn, error) {
-	cn, err := tls.Dial(network, addr, cfg)
-	if err != nil {
-		return nil, err
-	}
-	if err := cn.Handshake(); err != nil {
-		return nil, err
-	}
-	if !cfg.InsecureSkipVerify {
-		if err := cn.VerifyHostname(cfg.ServerName); err != nil {
+	return func(network, addr string, cfg *tls.Config) (net.Conn, error) {
+		tlsCn, err := t.dialTLSWithContext(ctx, network, addr, cfg)
+		if err != nil {
 			return nil, err
 		}
+		state := tlsCn.ConnectionState()
+		if p := state.NegotiatedProtocol; p != NextProtoTLS {
+			return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS)
+		}
+		if !state.NegotiatedProtocolIsMutual {
+			return nil, errors.New("http2: could not negotiate protocol mutually")
+		}
+		return tlsCn, nil
 	}
-	state := cn.ConnectionState()
-	if p := state.NegotiatedProtocol; p != NextProtoTLS {
-		return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, NextProtoTLS)
-	}
-	if !state.NegotiatedProtocolIsMutual {
-		return nil, errors.New("http2: could not negotiate protocol mutually")
-	}
-	return cn, nil
 }
 
 // disableKeepAlives reports whether connections should be closed as
@@ -923,46 +912,6 @@ func (cc *ClientConn) closeForLostPing() error {
 	return cc.closeForError(err)
 }
 
-const maxAllocFrameSize = 512 << 10
-
-// frameBuffer returns a scratch buffer suitable for writing DATA frames.
-// They're capped at the min of the peer's max frame size or 512KB
-// (kinda arbitrarily), but definitely capped so we don't allocate 4GB
-// bufers.
-func (cc *ClientConn) frameScratchBuffer() []byte {
-	cc.mu.Lock()
-	size := cc.maxFrameSize
-	if size > maxAllocFrameSize {
-		size = maxAllocFrameSize
-	}
-	for i, buf := range cc.freeBuf {
-		if len(buf) >= int(size) {
-			cc.freeBuf[i] = nil
-			cc.mu.Unlock()
-			return buf[:size]
-		}
-	}
-	cc.mu.Unlock()
-	return make([]byte, size)
-}
-
-func (cc *ClientConn) putFrameScratchBuffer(buf []byte) {
-	cc.mu.Lock()
-	defer cc.mu.Unlock()
-	const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate.
-	if len(cc.freeBuf) < maxBufs {
-		cc.freeBuf = append(cc.freeBuf, buf)
-		return
-	}
-	for i, old := range cc.freeBuf {
-		if old == nil {
-			cc.freeBuf[i] = buf
-			return
-		}
-	}
-	// forget about it.
-}
-
 // errRequestCanceled is a copy of net/http's errRequestCanceled because it's not
 // exported. At least they'll be DeepEqual for h1-vs-h2 comparisons tests.
 var errRequestCanceled = errors.New("net/http: request canceled")
@@ -1005,7 +954,7 @@ func checkConnHeaders(req *http.Request) error {
 	if vv := req.Header["Transfer-Encoding"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && vv[0] != "chunked") {
 		return fmt.Errorf("http2: invalid Transfer-Encoding request header: %q", vv)
 	}
-	if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !strings.EqualFold(vv[0], "close") && !strings.EqualFold(vv[0], "keep-alive")) {
+	if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !asciiEqualFold(vv[0], "close") && !asciiEqualFold(vv[0], "keep-alive")) {
 		return fmt.Errorf("http2: invalid Connection request header: %q", vv)
 	}
 	return nil
@@ -1305,11 +1254,35 @@ var (
 	errReqBodyTooLong = errors.New("http2: request body larger than specified content length")
 )
 
+// frameScratchBufferLen returns the length of a buffer to use for
+// outgoing request bodies to read/write to/from.
+//
+// It returns max(1, min(peer's advertised max frame size,
+// Request.ContentLength+1, 512KB)).
+func (cs *clientStream) frameScratchBufferLen(maxFrameSize int) int {
+	const max = 512 << 10
+	n := int64(maxFrameSize)
+	if n > max {
+		n = max
+	}
+	if cl := actualContentLength(cs.req); cl != -1 && cl+1 < n {
+		// Add an extra byte past the declared content-length to
+		// give the caller's Request.Body io.Reader a chance to
+		// give us more bytes than they declared, so we can catch it
+		// early.
+		n = cl + 1
+	}
+	if n < 1 {
+		return 1
+	}
+	return int(n) // doesn't truncate; max is 512K
+}
+
+var bufPool sync.Pool // of *[]byte
+
 func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (err error) {
 	cc := cs.cc
 	sentEnd := false // whether we sent the final DATA frame w/ END_STREAM
-	buf := cc.frameScratchBuffer()
-	defer cc.putFrameScratchBuffer(buf)
 
 	defer func() {
 		traceWroteRequest(cs.trace, err)
@@ -1328,9 +1301,24 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (
 	remainLen := actualContentLength(req)
 	hasContentLen := remainLen != -1
 
+	cc.mu.Lock()
+	maxFrameSize := int(cc.maxFrameSize)
+	cc.mu.Unlock()
+
+	// Scratch buffer for reading into & writing from.
+	scratchLen := cs.frameScratchBufferLen(maxFrameSize)
+	var buf []byte
+	if bp, ok := bufPool.Get().(*[]byte); ok && len(*bp) >= scratchLen {
+		defer bufPool.Put(bp)
+		buf = *bp
+	} else {
+		buf = make([]byte, scratchLen)
+		defer bufPool.Put(&buf)
+	}
+
 	var sawEOF bool
 	for !sawEOF {
-		n, err := body.Read(buf[:len(buf)-1])
+		n, err := body.Read(buf[:len(buf)])
 		if hasContentLen {
 			remainLen -= int64(n)
 			if remainLen == 0 && err == nil {
@@ -1341,8 +1329,9 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (
 				// to send the END_STREAM bit early, double-check that we're actually
 				// at EOF. Subsequent reads should return (0, EOF) at this point.
 				// If either value is different, we return an error in one of two ways below.
+				var scratch [1]byte
 				var n1 int
-				n1, err = body.Read(buf[n:])
+				n1, err = body.Read(scratch[:])
 				remainLen -= int64(n1)
 			}
 			if remainLen < 0 {
@@ -1412,10 +1401,6 @@ func (cs *clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (
 		}
 	}
 
-	cc.mu.Lock()
-	maxFrameSize := int(cc.maxFrameSize)
-	cc.mu.Unlock()
-
 	cc.wmu.Lock()
 	defer cc.wmu.Unlock()
 
@@ -1531,19 +1516,21 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 
 		var didUA bool
 		for k, vv := range req.Header {
-			if strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
+			if asciiEqualFold(k, "host") || asciiEqualFold(k, "content-length") {
 				// Host is :authority, already sent.
 				// Content-Length is automatic, set below.
 				continue
-			} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
-				strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
-				strings.EqualFold(k, "keep-alive") {
+			} else if asciiEqualFold(k, "connection") ||
+				asciiEqualFold(k, "proxy-connection") ||
+				asciiEqualFold(k, "transfer-encoding") ||
+				asciiEqualFold(k, "upgrade") ||
+				asciiEqualFold(k, "keep-alive") {
 				// Per 8.1.2.2 Connection-Specific Header
 				// Fields, don't send connection-specific
 				// fields. We have already checked if any
 				// are error-worthy so just ignore the rest.
 				continue
-			} else if strings.EqualFold(k, "user-agent") {
+			} else if asciiEqualFold(k, "user-agent") {
 				// Match Go's http1 behavior: at most one
 				// User-Agent. If set to nil or empty string,
 				// then omit it. Otherwise if not mentioned,
@@ -1556,7 +1543,7 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 				if vv[0] == "" {
 					continue
 				}
-			} else if strings.EqualFold(k, "cookie") {
+			} else if asciiEqualFold(k, "cookie") {
 				// Per 8.1.2.5 To allow for better compression efficiency, the
 				// Cookie header field MAY be split into separate header fields,
 				// each with one or more cookie-pairs.
@@ -1615,7 +1602,12 @@ func (cc *ClientConn) encodeHeaders(req *http.Request, addGzipHeader bool, trail
 
 	// Header list size is ok. Write the headers.
 	enumerateHeaders(func(name, value string) {
-		name = strings.ToLower(name)
+		name, ascii := asciiToLower(name)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			return
+		}
 		cc.writeHeader(name, value)
 		if traceHeaders {
 			traceWroteHeaderField(trace, name, value)
@@ -1663,9 +1655,14 @@ func (cc *ClientConn) encodeTrailers(req *http.Request) ([]byte, error) {
 	}
 
 	for k, vv := range req.Trailer {
+		lowKey, ascii := asciiToLower(k)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			continue
+		}
 		// Transfer-Encoding, etc.. have already been filtered at the
 		// start of RoundTrip
-		lowKey := strings.ToLower(k)
 		for _, v := range vv {
 			cc.writeHeader(lowKey, v)
 		}
diff --git a/vendor/golang.org/x/net/http2/write.go b/vendor/golang.org/x/net/http2/write.go
index 3849bc26..33f61398 100644
--- a/vendor/golang.org/x/net/http2/write.go
+++ b/vendor/golang.org/x/net/http2/write.go
@@ -341,7 +341,12 @@ func encodeHeaders(enc *hpack.Encoder, h http.Header, keys []string) {
 	}
 	for _, k := range keys {
 		vv := h[k]
-		k = lowerHeader(k)
+		k, ascii := lowerHeader(k)
+		if !ascii {
+			// Skip writing invalid headers. Per RFC 7540, Section 8.1.2, header
+			// field names have to be ASCII characters (just as in HTTP/1.x).
+			continue
+		}
 		if !validWireHeaderFieldName(k) {
 			// Skip it as backup paranoia. Per
 			// golang.org/issue/14048, these should