@samitouri / QOSAMI-X402Tunnel-1 / commits / e6a0a8de

sdk: add mitm detection in listener

Kim committed Mar 25, 2026 at 15:05 UTC e6a0a8debf7b145e76b4cf05ff665bfbe3ae6fbe

5 files changed +705 -2

docs/architecture.md

+24 -1

@@ -34,8 +34,10 @@ UDP client

34 ### TLS and Identity

36 - Relay terminates admin/API TLS on the root host and exposes `/v1/sign` for tenant-side keyless signing.

37 +- Control-plane HTTP (`/sdk/*`), reverse-session establishment (`/sdk/connect`), and tenant TLS are separate connections with different trust boundaries.

38 - Relay does not terminate tenant TLS. It peeks ClientHello for SNI and bridges raw encrypted bytes after routing.

39 - SDK/tunnel endpoints terminate tenant TLS locally with a keyless-backed signer that calls the relay.

40 +- In keyless TLS, the relay performs certificate private-key signing through `/v1/sign`, but the SDK/tunnel endpoint still runs the TLS server handshake and derives tenant TLS session keys locally.

41 - `/sdk/connect`, `/sdk/renew`, and `/sdk/unregister` are authorized by lease existence plus reverse token.

42 - `/sdk/register` requires the caller to supply the reverse token that later authorizes the lease lifecycle, but registration itself is not separately authenticated by that token.

43 - Relay URLs must use `https://`.

@@ -119,6 +121,7 @@ That distinction matters because `/sdk/connect` stops being ordinary HTTP once h

121 - Entry points can opt out of registry defaults and call `utils.NormalizeRelayURLs` directly when they need explicit relay inputs only

122 - `Listener`: validates one relay URL locally, then starts relay compatibility checks, lease registration, reverse session maintenance, and lease renewal in the background until ready

123 - `api_client.go`: internal relay client for control-plane requests, reverse session dialing, and internal QUIC tunnel setup

124 +- `mitm.go`: tenant-side TLS passthrough self-probe. The SDK opens a probe connection to its own public URL, compares TLS exporter values on both SDK-controlled ends, and logs suspected relay-side TLS termination on mismatch

125 - `ListenerConfig.RetryCount <= 0` means retry forever; positive values close the listener after the retry budget is exhausted

126 - `NewListener` callers provide explicit normalized relay URLs

127 - Default exposure flow is `Expose{Discovery: true} -> PublicURLs -> http.Server.Serve(exposure)`, with an opt-out path for explicit relay inputs only

@@ -127,6 +130,8 @@ That distinction matters because `/sdk/connect` stops being ordinary HTTP once h

130 - `Exposure.RelayURLs()` returns the configured normalized relay URLs, while `Exposure.PublicURLs()` returns only relays that are currently registered and ready

131 - Relay-aware entry inspection is reserved for advanced callers such as `portal-tunnel`

132 - Tenant TLS is created automatically through the relay keyless signer; callers do not provide a local self-signed fallback path

133 +- MITM self-probes are traffic-triggered, not periodic. A listener triggers at most one asynchronous probe per 30-second cooldown, and only after real tenant traffic performs I/O on an accepted connection

134 +- Probe identification does not use a dedicated ALPN or fixed plaintext marker. The first encrypted probe payload is `nonce + random padding`, and inbound probe matching is only attempted while a probe is in flight

135 - `Listener` embeds a `datagram.Session` for QUIC datagram transport (no separate UDP listener type)

136 - `Listener.AcceptDatagram()` / `SendDatagram()`: read/write datagram frames via the session

137 - `Listener.WaitDatagramReady()`: blocks until relay publishes `udp_addr` and `quic_addr`

@@ -163,6 +168,18 @@ That distinction matters because `/sdk/connect` stops being ordinary HTTP once h

168

169 Result: the relay decides routing, but tenant TLS termination still happens at the SDK/tunnel side.

170

171 +### Tenant TLS Self-Probe Detection

172 +

173 +1. After a real tenant connection begins I/O, the SDK may start one asynchronous self-probe for that listener if no probe is in flight and the 30-second cooldown has expired.

174 +2. The SDK opens a new TLS connection to its own public URL using the same tenant-facing TLS characteristics as normal traffic.

175 +3. The probe client exports TLS keying material (`ExportKeyingMaterial`) from that probe connection and stores it under a random nonce.

176 +4. The first encrypted probe payload is `16-byte nonce + random padding`; there is no fixed probe magic or dedicated ALPN.

177 +5. When the probe connection comes back through the relay and reaches the SDK-side tenant TLS terminator, the SDK peeks only the first 16 encrypted application bytes while a probe is pending.

178 +6. If those bytes match a pending nonce, the SDK exports keying material on the server side and compares it with the client-side exporter value.

179 +7. Matching exporter values mean the probe observed passthrough for that connection. A mismatch is logged as suspected relay-side TLS termination. A timeout is logged as probe failure, not proof of MITM.

180 +

181 +Result: this is a detect-only signal. It raises the cost of adaptive relay-side TLS termination, but it does not prove passthrough for every user connection.

182 +

183 ### UDP/QUIC Datagram Transport

184

185 1. SDK/tunnel registers a lease with `udp_enabled=true` via `POST /sdk/register`.

@@ -267,6 +284,9 @@ Cross-package public contract lives in:

284 - API envelope

285 - shared request/response DTOs

286 - lease metadata

287 +- `types/error.go`

288 + - shared API error codes

289 + - shared MITM self-probe reason codes

290 - `types/types.go`

291 - shared headers

292 - reverse marker constants

@@ -289,7 +309,9 @@ Relay-local frontend asset filenames stay in `cmd/relay-server`, not `types/`.

309 - root host A record

310 - wildcard host A record

311 - relay certificate renewal

292 -- SDK/tunnel fetches the relay certificate chain, verifies it covers tenant hostnames, and uses `/v1/sign` for remote signatures during tenant TLS handshakes

312 +- SDK/tunnel fetches the relay certificate chain from the relay root host, verifies that the leaf covers tenant hostnames, and builds a tenant-side `tls.Config` with a remote signer backed by `/v1/sign`

313 +- During tenant TLS handshake, the SDK/tunnel endpoint acts as the TLS server and derives tenant session keys locally; the relay only signs handshake digests and does not receive tenant TLS traffic secrets

314 +- Relay control-plane TLS and reverse-session setup still terminate on the relay's admin/API listener and are not protected by the tenant keyless TLS path

315

316 ## Design Properties

317

@@ -298,6 +320,7 @@ Relay-local frontend asset filenames stay in `cmd/relay-server`, not `types/`.

320 - Raw public UDP exposure with an internal QUIC datagram backhaul

321 - SNI-based routing with root-host fallback

322 - End-to-end tenant TLS with relay-backed keyless signing

323 +- Traffic-triggered detect-only MITM self-probing for probable relay-side TLS termination

324 - Per-lease reverse token authorization for reverse session lifecycle

325 - Lease-local stream and datagram ownership through per-lease transport runtimes

326 - Optional QUIC/UDP datagram transport coexisting with TCP on the same lease

sdk/listener.go

+26 -1

@@ -73,6 +73,8 @@ type Listener struct {

73 metadata types.LeaseMetadata

74 tlsConfig *tls.Config

75 tlsCloser io.Closer

76 +

77 + mitmManager *mitmManager

78 }

80 // NewListener creates one relay listener and its dedicated relay transport for one relay URL.

@@ -110,6 +112,7 @@ func NewListener(ctx context.Context, relayURL string, cfg ListenerConfig) (*Lis

112 registerBootstraps: append([]string(nil), initialBootstraps...),

113 metadata: cfg.Metadata.Copy(),

114 }

115 + l.mitmManager = newMITMManager(listenerCtx, l)

116 l.stream = transport.NewClientStream(readyTarget, handshakeTimeout)

117 if cfg.UDPEnabled {

118 l.datagram = transport.NewClientDatagram(func(err error) {

@@ -211,6 +214,10 @@ func (l *Listener) Close() error {

214 l.tlsCloser = nil

215 l.mu.Unlock()

216

217 + if l.mitmManager != nil {

218 + l.mitmManager.reset()

219 + }

220 +

221 if stream != nil {

222 stream.Drain()

223 }

@@ -237,7 +244,25 @@ func (l *Listener) Accept() (net.Conn, error) {

244 if l.stream == nil {

245 return nil, net.ErrClosed

246 }

240 - return l.stream.Accept(l.doneCh)

247 + for {

248 + conn, err := l.stream.Accept(l.doneCh)

249 + if err != nil {

250 + return nil, err

251 + }

252 +

253 + nextConn, handled, handleErr := l.mitmManager.maybeHandleConn(conn)

254 + if handleErr != nil {

255 + log.Debug().

256 + Err(handleErr).

257 + Str("relay_url", l.api.baseURL.String()).

258 + Str("lease_id", l.LeaseID()).

259 + Msg("mitm self-probe handling failed")

260 + }

261 + if handled {

262 + continue

263 + }

264 + return wrapMITMProbeConn(l.mitmManager, nextConn), nil

265 + }

266 }

267

268 func (l *Listener) Addr() net.Addr {

sdk/mitm.go new

+377

@@ -0,0 +1,377 @@

1 +package sdk

2 +

3 +import (

4 + "bufio"

5 + "bytes"

6 + "context"

7 + "crypto/rand"

8 + "crypto/tls"

9 + "encoding/hex"

10 + "errors"

11 + "fmt"

12 + "io"

13 + "net"

14 + "net/url"

15 + "sync"

16 + "time"

17 +

18 + "github.com/rs/zerolog/log"

19 +

20 + "github.com/gosuda/portal/v2/types"

21 + "github.com/gosuda/portal/v2/utils"

22 +)

23 +

24 +const (

25 + mitmProbeExporterLabel = "Portal-MITM-Probe-v1"

26 + mitmProbePeekTimeout = 100 * time.Millisecond

27 + mitmProbePaddingMin = 96

28 + mitmProbePaddingMax = 320

29 +

30 + defaultMITMProbeCooldown = 30 * time.Second

31 + defaultMITMProbeTimeout = 5 * time.Second

32 +)

33 +

34 +type MITMProbeReport struct {

35 + RelayURL string

36 + PublicURL string

37 + LeaseID string

38 + CheckedAt time.Time

39 + Detected bool

40 + Reason string

41 +}

42 +

43 +type mitmProbePending struct {

44 + expected []byte

45 + resultCh chan mitmProbeResult

46 +}

47 +

48 +type mitmProbeResult struct {

49 + matched bool

50 + reason string

51 +}

52 +

53 +type mitmManager struct {

54 + ctx context.Context

55 + listener *Listener

56 +

57 + mu sync.Mutex

58 + pending map[string]*mitmProbePending

59 + inFlight bool

60 + lastAt time.Time

61 +}

62 +

63 +func newMITMManager(ctx context.Context, listener *Listener) *mitmManager {

64 + return &mitmManager{

65 + ctx: ctx,

66 + listener: listener,

67 + pending: make(map[string]*mitmProbePending),

68 + }

69 +}

70 +

71 +func (m *mitmManager) reset() {

72 + m.mu.Lock()

73 + clear(m.pending)

74 + m.inFlight = false

75 + m.lastAt = time.Time{}

76 + m.mu.Unlock()

77 +}

78 +

79 +func (m *mitmManager) probeTLSPassthrough(ctx context.Context) (MITMProbeReport, error) {

80 + report := MITMProbeReport{

81 + CheckedAt: time.Now(),

82 + }

83 + l := m.listener

84 + if l == nil || l.api == nil || l.api.baseURL == nil {

85 + return report, errors.New("listener is not ready")

86 + }

87 +

88 + publicURL := l.PublicURL()

89 + if publicURL == "" {

90 + return report, errors.New("listener is not registered")

91 + }

92 +

93 + hostname := l.Hostname()

94 + if hostname == "" {

95 + return report, errors.New("listener hostname is unavailable")

96 + }

97 +

98 + probeCtx, cancel := context.WithTimeout(ctx, defaultMITMProbeTimeout)

99 + defer cancel()

100 +

101 + nonceRaw := make([]byte, 16)

102 + if _, err := io.ReadFull(rand.Reader, nonceRaw); err != nil {

103 + return report, fmt.Errorf("generate probe nonce: %w", err)

104 + }

105 + nonceHex := hex.EncodeToString(nonceRaw)

106 +

107 + report.RelayURL = l.api.baseURL.String()

108 + report.PublicURL = publicURL

109 + report.LeaseID = l.LeaseID()

110 +

111 + parsedURL, err := url.Parse(publicURL)

112 + if err != nil {

113 + return report, fmt.Errorf("parse public url: %w", err)

114 + }

115 +

116 + dialer := &tls.Dialer{

117 + NetDialer: &net.Dialer{Timeout: l.api.dialTimeout},

118 + Config: m.clientTLSConfig(hostname),

119 + }

120 + conn, err := dialer.DialContext(probeCtx, "tcp", utils.EnsurePort(parsedURL.Host))

121 + if err != nil {

122 + return report, fmt.Errorf("dial mitm probe: %w", err)

123 + }

124 + defer conn.Close()

125 +

126 + tlsConn, ok := conn.(*tls.Conn)

127 + if !ok {

128 + return report, errors.New("mitm probe connection is not tls")

129 + }

130 +

131 + clientState := tlsConn.ConnectionState()

132 + expected, err := (&clientState).ExportKeyingMaterial(mitmProbeExporterLabel, nil, 32)

133 + if err != nil {

134 + return report, fmt.Errorf("export client probe keying material: %w", err)

135 + }

136 + resultCh, cleanupProbe := m.startProbe(nonceHex, expected)

137 + defer cleanupProbe()

138 +

139 + paddingLen := mitmProbePaddingMin

140 + if mitmProbePaddingMax > mitmProbePaddingMin {

141 + var paddingSeed [1]byte

142 + if _, err := io.ReadFull(rand.Reader, paddingSeed[:]); err != nil {

143 + return report, fmt.Errorf("generate probe padding length: %w", err)

144 + }

145 + paddingLen += int(paddingSeed[0]) % (mitmProbePaddingMax - mitmProbePaddingMin + 1)

146 + }

147 +

148 + frame := make([]byte, len(nonceRaw)+paddingLen)

149 + copy(frame, nonceRaw)

150 + if _, err := io.ReadFull(rand.Reader, frame[len(nonceRaw):]); err != nil {

151 + return report, fmt.Errorf("generate probe padding: %w", err)

152 + }

153 + if _, err := conn.Write(frame); err != nil {

154 + return report, fmt.Errorf("write mitm probe: %w", err)

155 + }

156 +

157 + select {

158 + case result := <-resultCh:

159 + report.Detected = !result.matched

160 + report.Reason = result.reason

161 + return report, nil

162 + case <-probeCtx.Done():

163 + report.Detected = false

164 + report.Reason = types.MITMProbeReasonProbeTimeout

165 + if errors.Is(probeCtx.Err(), context.DeadlineExceeded) {

166 + return report, nil

167 + }

168 + return report, probeCtx.Err()

169 + }

170 +}

171 +

172 +func (m *mitmManager) clientTLSConfig(hostname string) *tls.Config {

173 + probeTLSConf := &tls.Config{

174 + ServerName: hostname,

175 + InsecureSkipVerify: true,

176 + }

177 +

178 + l := m.listener

179 + l.mu.Lock()

180 + defer l.mu.Unlock()

181 +

182 + if l.tlsConfig != nil {

183 + probeTLSConf.MinVersion = l.tlsConfig.MinVersion

184 + probeTLSConf.MaxVersion = l.tlsConfig.MaxVersion

185 + if len(l.tlsConfig.NextProtos) > 0 {

186 + probeTLSConf.NextProtos = append([]string(nil), l.tlsConfig.NextProtos...)

187 + }

188 + }

189 + return probeTLSConf

190 +}

191 +

192 +func (m *mitmManager) maybeStart() {

193 + l := m.listener

194 + if l.closed() {

195 + return

196 + }

197 +

198 + m.mu.Lock()

199 + if m.inFlight || !m.lastAt.IsZero() && time.Since(m.lastAt) < defaultMITMProbeCooldown {

200 + m.mu.Unlock()

201 + return

202 + }

203 + m.inFlight = true

204 + m.mu.Unlock()

205 +

206 + go func() {

207 + report, err := m.probeTLSPassthrough(m.ctx)

208 + m.finish(err == nil && report.Reason != types.MITMProbeReasonProbeTimeout)

209 + m.logResult(report, err)

210 + }()

211 +}

212 +

213 +func (m *mitmManager) finish(success bool) {

214 + m.mu.Lock()

215 + m.inFlight = false

216 + if success {

217 + m.lastAt = time.Now()

218 + }

219 + m.mu.Unlock()

220 +}

221 +

222 +func (m *mitmManager) logResult(report MITMProbeReport, err error) {

223 + l := m.listener

224 + switch {

225 + case l.closed():

226 + return

227 + case err != nil:

228 + if errors.Is(err, context.Canceled) || errors.Is(err, net.ErrClosed) {

229 + return

230 + }

231 + log.Warn().

232 + Err(err).

233 + Str("relay_url", l.api.baseURL.String()).

234 + Str("lease_id", l.LeaseID()).

235 + Msg("tls passthrough self-probe failed")

236 + case report.Reason == types.MITMProbeReasonProbeTimeout:

237 + log.Warn().

238 + Str("relay_url", report.RelayURL).

239 + Str("public_url", report.PublicURL).

240 + Str("lease_id", report.LeaseID).

241 + Msg("tls self-probe timed out before passthrough could be verified")

242 + case report.Detected:

243 + log.Warn().

244 + Str("reason", report.Reason).

245 + Str("relay_url", report.RelayURL).

246 + Str("public_url", report.PublicURL).

247 + Str("lease_id", report.LeaseID).

248 + Msg("tls termination suspected by self-probe")

249 + default:

250 + log.Debug().

251 + Str("relay_url", report.RelayURL).

252 + Str("public_url", report.PublicURL).

253 + Str("lease_id", report.LeaseID).

254 + Msg("tls passthrough self-probe passed")

255 + }

256 +}

257 +

258 +func (m *mitmManager) maybeHandleConn(conn net.Conn) (net.Conn, bool, error) {

259 + if conn == nil {

260 + return conn, false, nil

261 + }

262 +

263 + m.mu.Lock()

264 + hasPending := len(m.pending) > 0

265 + m.mu.Unlock()

266 + if !hasPending {

267 + return conn, false, nil

268 + }

269 +

270 + tlsConn, ok := conn.(*tls.Conn)

271 + if !ok {

272 + return conn, false, nil

273 + }

274 +

275 + frameSize := 16

276 + reader := bufio.NewReaderSize(conn, frameSize)

277 + _ = conn.SetReadDeadline(time.Now().Add(mitmProbePeekTimeout))

278 + peeked, err := reader.Peek(frameSize)

279 + defer conn.SetReadDeadline(time.Time{})

280 + if err != nil {

281 + return wrapBufferedConn(conn, reader), false, nil

282 + }

283 +

284 + nonceHex := hex.EncodeToString(peeked[:frameSize])

285 + m.mu.Lock()

286 + _, ok = m.pending[nonceHex]

287 + m.mu.Unlock()

288 + if !ok {

289 + return wrapBufferedConn(conn, reader), false, nil

290 + }

291 +

292 + defer conn.Close()

293 +

294 + frame := make([]byte, frameSize)

295 + if _, err := io.ReadFull(reader, frame); err != nil {

296 + return nil, true, fmt.Errorf("read mitm probe frame: %w", err)

297 + }

298 +

299 + serverState := tlsConn.ConnectionState()

300 + actual, err := (&serverState).ExportKeyingMaterial(mitmProbeExporterLabel, nil, 32)

301 + if err != nil {

302 + return nil, true, fmt.Errorf("export server probe keying material: %w", err)

303 + }

304 +

305 + m.completeProbe(nonceHex, actual)

306 + return nil, true, nil

307 +}

308 +

309 +func (m *mitmManager) startProbe(nonce string, expected []byte) (<-chan mitmProbeResult, func()) {

310 + m.mu.Lock()

311 + state := &mitmProbePending{

312 + expected: append([]byte(nil), expected...),

313 + resultCh: make(chan mitmProbeResult, 1),

314 + }

315 + m.pending[nonce] = state

316 + m.mu.Unlock()

317 +

318 + return state.resultCh, func() {

319 + m.mu.Lock()

320 + delete(m.pending, nonce)

321 + m.mu.Unlock()

322 + }

323 +}

324 +

325 +func (m *mitmManager) completeProbe(nonce string, actual []byte) {

326 + m.mu.Lock()

327 + state := m.pending[nonce]

328 + m.mu.Unlock()

329 + if state == nil {

330 + return

331 + }

332 +

333 + result := mitmProbeResult{

334 + matched: bytes.Equal(state.expected, actual),

335 + }

336 + if !result.matched {

337 + result.reason = types.MITMProbeReasonExporterMismatch

338 + }

339 +

340 + select {

341 + case state.resultCh <- result:

342 + default:

343 + }

344 +}

345 +

346 +func wrapMITMProbeConn(manager *mitmManager, conn net.Conn) net.Conn {

347 + if conn == nil {

348 + return conn

349 + }

350 + return &mitmProbeConn{Conn: conn, manager: manager}

351 +}

352 +

353 +type mitmProbeConn struct {

354 + net.Conn

355 + manager *mitmManager

356 + startOnce sync.Once

357 +}

358 +

359 +func (c *mitmProbeConn) Read(p []byte) (int, error) {

360 + n, err := c.Conn.Read(p)

361 + if n > 0 {

362 + c.startOnce.Do(func() {

363 + c.manager.maybeStart()

364 + })

365 + }

366 + return n, err

367 +}

368 +

369 +func (c *mitmProbeConn) Write(p []byte) (int, error) {

370 + n, err := c.Conn.Write(p)

371 + if n > 0 {

372 + c.startOnce.Do(func() {

373 + c.manager.maybeStart()

374 + })

375 + }

376 + return n, err

377 +}

sdk/mitm_test.go new

+275

@@ -0,0 +1,275 @@

1 +package sdk

2 +

3 +import (

4 + "bytes"

5 + "context"

6 + "crypto/ecdsa"

7 + "crypto/elliptic"

8 + "crypto/rand"

9 + "crypto/tls"

10 + "crypto/x509"

11 + "crypto/x509/pkix"

12 + "encoding/hex"

13 + "encoding/pem"

14 + "io"

15 + "math/big"

16 + "net"

17 + "testing"

18 + "time"

19 +

20 + "github.com/gosuda/portal/v2/types"

21 +)

22 +

23 +func TestMITMProbeConnMatchesExporter(t *testing.T) {

24 + clientConn, serverConn := newMITMProbeTLSPair(t)

25 + defer closeMITMProbeTLSConn(clientConn)

26 + defer closeMITMProbeTLSConn(serverConn)

27 +

28 + listener := &Listener{}

29 + listener.mitmManager = newMITMManager(context.Background(), listener)

30 +

31 + nonce := make([]byte, 16)

32 + if _, err := rand.Read(nonce); err != nil {

33 + t.Fatalf("rand.Read() error = %v", err)

34 + }

35 + nonceHex := hex.EncodeToString(nonce)

36 + clientState := clientConn.ConnectionState()

37 + expected, err := (&clientState).ExportKeyingMaterial(mitmProbeExporterLabel, nil, 32)

38 + if err != nil {

39 + t.Fatalf("client ExportKeyingMaterial() error = %v", err)

40 + }

41 + resultCh, cleanupProbe := listener.mitmManager.startProbe(nonceHex, expected)

42 + defer cleanupProbe()

43 +

44 + handleDone := make(chan struct{})

45 + go func() {

46 + defer close(handleDone)

47 + nextConn, handled, err := listener.mitmManager.maybeHandleConn(serverConn)

48 + if err != nil {

49 + t.Errorf("maybeHandleConn() error = %v", err)

50 + return

51 + }

52 + if nextConn != nil {

53 + t.Error("maybeHandleConn() returned passthrough conn for probe")

54 + }

55 + if !handled {

56 + t.Error("maybeHandleConn() handled = false, want true")

57 + }

58 + }()

59 +

60 + frame := append([]byte(nil), nonce...)

61 + frame = append(frame, bytes.Repeat([]byte{0xAB}, 128)...)

62 + if _, err := clientConn.Write(frame); err != nil {

63 + t.Fatalf("clientConn.Write() error = %v", err)

64 + }

65 + _ = clientConn.Close()

66 +

67 + select {

68 + case result := <-resultCh:

69 + if !result.matched {

70 + t.Fatalf("probe matched = false, reason = %q", result.reason)

71 + }

72 + case <-time.After(2 * time.Second):

73 + t.Fatal("timed out waiting for probe result")

74 + }

75 +

76 + select {

77 + case <-handleDone:

78 + case <-time.After(2 * time.Second):

79 + t.Fatal("timed out waiting for probe handler")

80 + }

81 +}

82 +

83 +func TestMITMProbeConnDetectsExporterMismatch(t *testing.T) {

84 + clientConn, serverConn := newMITMProbeTLSPair(t)

85 + defer closeMITMProbeTLSConn(clientConn)

86 + defer closeMITMProbeTLSConn(serverConn)

87 +

88 + listener := &Listener{}

89 + listener.mitmManager = newMITMManager(context.Background(), listener)

90 +

91 + nonce := make([]byte, 16)

92 + if _, err := rand.Read(nonce); err != nil {

93 + t.Fatalf("rand.Read() error = %v", err)

94 + }

95 + nonceHex := hex.EncodeToString(nonce)

96 + resultCh, cleanupProbe := listener.mitmManager.startProbe(nonceHex, make([]byte, 32))

97 + defer cleanupProbe()

98 +

99 + handleDone := make(chan struct{})

100 + go func() {

101 + defer close(handleDone)

102 + nextConn, handled, err := listener.mitmManager.maybeHandleConn(serverConn)

103 + if err != nil {

104 + t.Errorf("maybeHandleConn() error = %v", err)

105 + return

106 + }

107 + if nextConn != nil {

108 + t.Error("maybeHandleConn() returned passthrough conn for probe")

109 + }

110 + if !handled {

111 + t.Error("maybeHandleConn() handled = false, want true")

112 + }

113 + }()

114 +

115 + frame := append([]byte(nil), nonce...)

116 + frame = append(frame, bytes.Repeat([]byte{0xCD}, 128)...)

117 + if _, err := clientConn.Write(frame); err != nil {

118 + t.Fatalf("clientConn.Write() error = %v", err)

119 + }

120 + _ = clientConn.Close()

121 +

122 + select {

123 + case result := <-resultCh:

124 + if result.matched {

125 + t.Fatal("probe matched = true, want false")

126 + }

127 + if result.reason != types.MITMProbeReasonExporterMismatch {

128 + t.Fatalf("probe reason = %q, want %q", result.reason, types.MITMProbeReasonExporterMismatch)

129 + }

130 + case <-time.After(2 * time.Second):

131 + t.Fatal("timed out waiting for probe result")

132 + }

133 +

134 + select {

135 + case <-handleDone:

136 + case <-time.After(2 * time.Second):

137 + t.Fatal("timed out waiting for probe handler")

138 + }

139 +}

140 +

141 +func TestMITMProbeConnPassesThroughNormalTraffic(t *testing.T) {

142 + clientConn, serverConn := newMITMProbeTLSPair(t)

143 + defer closeMITMProbeTLSConn(clientConn)

144 + defer closeMITMProbeTLSConn(serverConn)

145 +

146 + listener := &Listener{}

147 + listener.mitmManager = newMITMManager(context.Background(), listener)

148 +

149 + type handleResult struct {

150 + conn net.Conn

151 + handled bool

152 + err error

153 + }

154 + handleResultCh := make(chan handleResult, 1)

155 + go func() {

156 + nextConn, handled, err := listener.mitmManager.maybeHandleConn(serverConn)

157 + handleResultCh <- handleResult{conn: nextConn, handled: handled, err: err}

158 + }()

159 +

160 + payload := []byte("GET / HTTP/1.1\r\nHost: localhost\r\n\r\n")

161 + var result handleResult

162 + select {

163 + case result = <-handleResultCh:

164 + case <-time.After(2 * time.Second):

165 + t.Fatal("timed out waiting for passthrough result")

166 + }

167 +

168 + if result.err != nil {

169 + t.Fatalf("maybeHandleConn() error = %v", result.err)

170 + }

171 + if result.handled {

172 + t.Fatal("maybeHandleConn() handled = true, want false")

173 + }

174 + if result.conn == nil {

175 + t.Fatal("maybeHandleConn() returned nil passthrough conn")

176 + }

177 +

178 + writeErrCh := make(chan error, 1)

179 + go func() {

180 + _, err := clientConn.Write(payload)

181 + writeErrCh <- err

182 + }()

183 +

184 + got := make([]byte, len(payload))

185 + if _, err := io.ReadFull(result.conn, got); err != nil {

186 + t.Fatalf("ReadFull() error = %v", err)

187 + }

188 + select {

189 + case err := <-writeErrCh:

190 + if err != nil {

191 + t.Fatalf("clientConn.Write() error = %v", err)

192 + }

193 + case <-time.After(2 * time.Second):

194 + t.Fatal("timed out waiting for client write")

195 + }

196 + if !bytes.Equal(got, payload) {

197 + t.Fatalf("passthrough payload = %q, want %q", got, payload)

198 + }

199 +}

200 +

201 +func newMITMProbeTLSPair(t *testing.T) (*tls.Conn, *tls.Conn) {

202 + t.Helper()

203 +

204 + cert := newMITMProbeCertificate(t)

205 + clientRaw, serverRaw := net.Pipe()

206 + clientConn := tls.Client(clientRaw, &tls.Config{

207 + InsecureSkipVerify: true,

208 + MinVersion: tls.VersionTLS13,

209 + NextProtos: []string{"http/1.1"},

210 + })

211 + serverConn := tls.Server(serverRaw, &tls.Config{

212 + Certificates: []tls.Certificate{cert},

213 + MinVersion: tls.VersionTLS13,

214 + NextProtos: []string{"http/1.1"},

215 + })

216 +

217 + errCh := make(chan error, 2)

218 + go func() { errCh <- serverConn.HandshakeContext(context.Background()) }()

219 + go func() { errCh <- clientConn.HandshakeContext(context.Background()) }()

220 + for range 2 {

221 + if err := <-errCh; err != nil {

222 + t.Fatalf("TLS handshake error = %v", err)

223 + }

224 + }

225 +

226 + return clientConn, serverConn

227 +}

228 +

229 +func closeMITMProbeTLSConn(conn *tls.Conn) {

230 + if conn == nil {

231 + return

232 + }

233 + _ = conn.SetDeadline(time.Now())

234 + _ = conn.Close()

235 +}

236 +

237 +func newMITMProbeCertificate(t *testing.T) tls.Certificate {

238 + t.Helper()

239 +

240 + privateKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)

241 + if err != nil {

242 + t.Fatalf("GenerateKey() error = %v", err)

243 + }

244 +

245 + template := &x509.Certificate{

246 + SerialNumber: big.NewInt(1),

247 + Subject: pkix.Name{

248 + CommonName: "portal-mitm-probe",

249 + },

250 + NotBefore: time.Now().Add(-time.Hour),

251 + NotAfter: time.Now().Add(time.Hour),

252 + KeyUsage: x509.KeyUsageDigitalSignature | x509.KeyUsageKeyEncipherment,

253 + ExtKeyUsage: []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},

254 + BasicConstraintsValid: true,

255 + DNSNames: []string{"localhost"},

256 + }

257 +

258 + der, err := x509.CreateCertificate(rand.Reader, template, template, &privateKey.PublicKey, privateKey)

259 + if err != nil {

260 + t.Fatalf("CreateCertificate() error = %v", err)

261 + }

262 +

263 + keyDER, err := x509.MarshalPKCS8PrivateKey(privateKey)

264 + if err != nil {

265 + t.Fatalf("MarshalPKCS8PrivateKey() error = %v", err)

266 + }

267 +

268 + certPEM := pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: der})

269 + keyPEM := pem.EncodeToMemory(&pem.Block{Type: "PRIVATE KEY", Bytes: keyDER})

270 + cert, err := tls.X509KeyPair(certPEM, keyPEM)

271 + if err != nil {

272 + t.Fatalf("X509KeyPair() error = %v", err)

273 + }

274 + return cert

275 +}

types/error.go

@@ -24,4 +24,7 @@ const (

24 APIErrorCodeUDPDisabled = "udp_disabled"

25 APIErrorCodeUDPCapacityExceeded = "udp_capacity_exceeded"

26 APIErrorCodeTransportMismatch = "transport_mismatch"

27 +

28 + MITMProbeReasonExporterMismatch = "tls_exporter_mismatch"

29 + MITMProbeReasonProbeTimeout = "probe_timeout"

30 )