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tailscale/control/controlclient/noise_test.go

210 lines
5.6 KiB
Go

// Copyright (c) 2022 Tailscale Inc & 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 controlclient
import (
"context"
"encoding/binary"
"encoding/json"
"io"
"math"
"net/http"
"net/http/httptest"
"testing"
"time"
"golang.org/x/net/http2"
"tailscale.com/control/controlhttp"
"tailscale.com/net/tsdial"
"tailscale.com/tailcfg"
"tailscale.com/types/key"
"tailscale.com/types/logger"
)
// maxAllowedNoiseVersion is the highest we expect the Tailscale
// capability version to ever get. It's a value close to 2^16, but
// with enough leeway that we get a very early warning that it's time
// to rework the wire protocol to allow larger versions, while still
// giving us headroom to bump this test and fix the build.
//
// Code elsewhere in the client will panic() if the tailcfg capability
// version exceeds 16 bits, so take a failure of this test seriously.
const maxAllowedNoiseVersion = math.MaxUint16 - 5000
func TestNoiseVersion(t *testing.T) {
if tailcfg.CurrentCapabilityVersion > maxAllowedNoiseVersion {
t.Fatalf("tailcfg.CurrentCapabilityVersion is %d, want <=%d", tailcfg.CurrentCapabilityVersion, maxAllowedNoiseVersion)
}
}
type noiseClientTest struct {
sendEarlyPayload bool
}
func TestNoiseClientHTTP2Upgrade(t *testing.T) {
noiseClientTest{}.run(t)
}
func TestNoiseClientHTTP2Upgrade_earlyPayload(t *testing.T) {
noiseClientTest{
sendEarlyPayload: true,
}.run(t)
}
func (tt noiseClientTest) run(t *testing.T) {
serverPrivate := key.NewMachine()
clientPrivate := key.NewMachine()
chalPrivate := key.NewChallenge()
const msg = "Hello, client"
h2 := &http2.Server{}
hs := httptest.NewServer(&Upgrader{
h2srv: h2,
noiseKeyPriv: serverPrivate,
sendEarlyPayload: tt.sendEarlyPayload,
challenge: chalPrivate,
httpBaseConfig: &http.Server{
Handler: http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/plain")
io.WriteString(w, msg)
}),
},
})
defer hs.Close()
dialer := new(tsdial.Dialer)
nc, err := NewNoiseClient(clientPrivate, serverPrivate.Public(), hs.URL, dialer, nil)
if err != nil {
t.Fatal(err)
}
// Get a conn and verify it read its early payload before the http/2
// handshake.
ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
defer cancel()
c, err := nc.getConn(ctx)
if err != nil {
t.Fatal(err)
}
select {
case <-c.earlyPayloadReady:
gotNonNil := c.earlyPayload != nil
if gotNonNil != tt.sendEarlyPayload {
t.Errorf("sendEarlyPayload = %v but got earlyPayload = %T", tt.sendEarlyPayload, c.earlyPayload)
}
if c.earlyPayload != nil {
if c.earlyPayload.NodeKeyChallenge != chalPrivate.Public() {
t.Errorf("earlyPayload.NodeKeyChallenge = %v; want %v", c.earlyPayload.NodeKeyChallenge, chalPrivate.Public())
}
}
case <-ctx.Done():
t.Fatal("timed out waiting for didReadHeaderCh")
}
checkRes := func(t *testing.T, res *http.Response) {
t.Helper()
defer res.Body.Close()
all, err := io.ReadAll(res.Body)
if err != nil {
t.Fatal(err)
}
if string(all) != msg {
t.Errorf("got response %q; want %q", all, msg)
}
}
// And verify we can do HTTP/2 against that conn.
res, err := (&http.Client{Transport: c}).Get("https://unused.example/")
if err != nil {
t.Fatal(err)
}
checkRes(t, res)
// And try using the high-level nc.post API as well.
res, err = nc.post(context.Background(), "/", nil)
if err != nil {
t.Fatal(err)
}
checkRes(t, res)
}
// Upgrader is an http.Handler that hijacks and upgrades POST-with-Upgrade
// request to a Tailscale 2021 connection, then hands the resulting
// controlbase.Conn off to h2srv.
type Upgrader struct {
// h2srv is that will handle requests after the
// connection has been upgraded to HTTP/2-over-noise.
h2srv *http2.Server
// httpBaseConfig is the http1 server config that h2srv is
// associated with.
httpBaseConfig *http.Server
logf logger.Logf
noiseKeyPriv key.MachinePrivate
challenge key.ChallengePrivate
sendEarlyPayload bool
}
func (up *Upgrader) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if up == nil || up.h2srv == nil {
http.Error(w, "invalid server config", http.StatusServiceUnavailable)
return
}
if r.URL.Path != "/ts2021" {
http.Error(w, "ts2021 upgrader installed at wrong path", http.StatusBadGateway)
return
}
if up.noiseKeyPriv.IsZero() {
http.Error(w, "keys not available", http.StatusServiceUnavailable)
return
}
earlyWriteFn := func(protocolVersion int, w io.Writer) error {
if !up.sendEarlyPayload {
return nil
}
earlyJSON, err := json.Marshal(&tailcfg.EarlyNoise{
NodeKeyChallenge: up.challenge.Public(),
})
if err != nil {
return err
}
// 5 bytes that won't be mistaken for an HTTP/2 frame:
// https://httpwg.org/specs/rfc7540.html#rfc.section.4.1 (Especially not
// an HTTP/2 settings frame, which isn't of type 'T')
var notH2Frame [5]byte
copy(notH2Frame[:], earlyPayloadMagic)
var lenBuf [4]byte
binary.BigEndian.PutUint32(lenBuf[:], uint32(len(earlyJSON)))
// These writes are all buffered by caller, so fine to do them
// separately:
if _, err := w.Write(notH2Frame[:]); err != nil {
return err
}
if _, err := w.Write(lenBuf[:]); err != nil {
return err
}
if _, err := w.Write(earlyJSON[:]); err != nil {
return err
}
return nil
}
cbConn, err := controlhttp.AcceptHTTP(r.Context(), w, r, up.noiseKeyPriv, earlyWriteFn)
if err != nil {
up.logf("controlhttp: Accept: %v", err)
return
}
defer cbConn.Close()
up.h2srv.ServeConn(cbConn, &http2.ServeConnOpts{
BaseConfig: up.httpBaseConfig,
})
}