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// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package controlbase
import (
"bytes"
"context"
"io"
"strings"
"testing"
"time"
"tailscale.com/net/memnet"
"tailscale.com/types/key"
)
func TestHandshake(t *testing.T) {
var (
clientConn, serverConn = memnet.NewConn("noise", 128000)
serverKey = key.NewMachine()
clientKey = key.NewMachine()
server *Conn
serverErr = make(chan error, 1)
)
go func() {
var err error
server, err = Server(context.Background(), serverConn, serverKey, nil)
serverErr <- err
}()
client, err := Client(context.Background(), clientConn, clientKey, serverKey.Public(), testProtocolVersion)
if err != nil {
t.Fatalf("client connection failed: %v", err)
}
if err := <-serverErr; err != nil {
t.Fatalf("server connection failed: %v", err)
}
if client.HandshakeHash() != server.HandshakeHash() {
t.Fatal("client and server disagree on handshake hash")
}
if client.ProtocolVersion() != int(testProtocolVersion) {
t.Fatalf("client reporting wrong protocol version %d, want %d", client.ProtocolVersion(), testProtocolVersion)
}
if client.ProtocolVersion() != server.ProtocolVersion() {
t.Fatalf("peers disagree on protocol version, client=%d server=%d", client.ProtocolVersion(), server.ProtocolVersion())
}
if client.Peer() != serverKey.Public() {
t.Fatal("client peer key isn't serverKey")
}
if server.Peer() != clientKey.Public() {
t.Fatal("client peer key isn't serverKey")
}
}
// Check that handshaking repeatedly with the same long-term keys
// result in different handshake hashes and wire traffic.
func TestNoReuse(t *testing.T) {
var (
hashes = map[[32]byte]bool{}
clientHandshakes = map[[96]byte]bool{}
serverHandshakes = map[[48]byte]bool{}
packets = map[[32]byte]bool{}
)
for range 10 {
var (
clientRaw, serverRaw = memnet.NewConn("noise", 128000)
clientBuf, serverBuf bytes.Buffer
clientConn = &readerConn{clientRaw, io.TeeReader(clientRaw, &clientBuf)}
serverConn = &readerConn{serverRaw, io.TeeReader(serverRaw, &serverBuf)}
serverKey = key.NewMachine()
clientKey = key.NewMachine()
server *Conn
serverErr = make(chan error, 1)
)
go func() {
var err error
server, err = Server(context.Background(), serverConn, serverKey, nil)
serverErr <- err
}()
client, err := Client(context.Background(), clientConn, clientKey, serverKey.Public(), testProtocolVersion)
if err != nil {
t.Fatalf("client connection failed: %v", err)
}
if err := <-serverErr; err != nil {
t.Fatalf("server connection failed: %v", err)
}
var clientHS [96]byte
copy(clientHS[:], serverBuf.Bytes())
if clientHandshakes[clientHS] {
t.Fatal("client handshake seen twice")
}
clientHandshakes[clientHS] = true
var serverHS [48]byte
copy(serverHS[:], clientBuf.Bytes())
if serverHandshakes[serverHS] {
t.Fatal("server handshake seen twice")
}
serverHandshakes[serverHS] = true
clientBuf.Reset()
serverBuf.Reset()
cb := sinkReads(client)
sb := sinkReads(server)
if hashes[client.HandshakeHash()] {
t.Fatalf("handshake hash %v seen twice", client.HandshakeHash())
}
hashes[client.HandshakeHash()] = true
// Sending 14 bytes turns into 32 bytes on the wire (+16 for
// the chacha20poly1305 overhead, +2 length header)
if _, err := io.WriteString(client, strings.Repeat("a", 14)); err != nil {
t.Fatalf("client>server write failed: %v", err)
}
if _, err := io.WriteString(server, strings.Repeat("b", 14)); err != nil {
t.Fatalf("server>client write failed: %v", err)
}
// Wait for the bytes to be read, so we know they've traveled end to end
cb.String(14)
sb.String(14)
var clientWire, serverWire [32]byte
copy(clientWire[:], clientBuf.Bytes())
copy(serverWire[:], serverBuf.Bytes())
if packets[clientWire] {
t.Fatalf("client wire traffic seen twice")
}
packets[clientWire] = true
if packets[serverWire] {
t.Fatalf("server wire traffic seen twice")
}
packets[serverWire] = true
server.Close()
client.Close()
}
}
// tamperReader wraps a reader and mutates the Nth byte.
type tamperReader struct {
r io.Reader
n int
total int
}
func (r *tamperReader) Read(bs []byte) (int, error) {
n, err := r.r.Read(bs)
if off := r.n - r.total; off >= 0 && off < n {
bs[off] += 1
}
r.total += n
return n, err
}
func TestTampering(t *testing.T) {
// Tamper with every byte of the client initiation message.
for i := range 101 {
var (
clientConn, serverRaw = memnet.NewConn("noise", 128000)
serverConn = &readerConn{serverRaw, &tamperReader{serverRaw, i, 0}}
serverKey = key.NewMachine()
clientKey = key.NewMachine()
serverErr = make(chan error, 1)
)
go func() {
_, err := Server(context.Background(), serverConn, serverKey, nil)
// If the server failed, we have to close the Conn to
// unblock the client.
if err != nil {
serverConn.Close()
}
serverErr <- err
}()
_, err := Client(context.Background(), clientConn, clientKey, serverKey.Public(), testProtocolVersion)
if err == nil {
t.Fatal("client connection succeeded despite tampering")
}
if err := <-serverErr; err == nil {
t.Fatalf("server connection succeeded despite tampering")
}
}
// Tamper with every byte of the server response message.
for i := range 51 {
var (
clientRaw, serverConn = memnet.NewConn("noise", 128000)
clientConn = &readerConn{clientRaw, &tamperReader{clientRaw, i, 0}}
serverKey = key.NewMachine()
clientKey = key.NewMachine()
serverErr = make(chan error, 1)
)
go func() {
_, err := Server(context.Background(), serverConn, serverKey, nil)
serverErr <- err
}()
_, err := Client(context.Background(), clientConn, clientKey, serverKey.Public(), testProtocolVersion)
if err == nil {
t.Fatal("client connection succeeded despite tampering")
}
// The server shouldn't fail, because the tampering took place
// in its response.
if err := <-serverErr; err != nil {
t.Fatalf("server connection failed despite no tampering: %v", err)
}
}
// Tamper with every byte of the first server>client transport message.
for i := range 30 {
var (
clientRaw, serverConn = memnet.NewConn("noise", 128000)
clientConn = &readerConn{clientRaw, &tamperReader{clientRaw, 51 + i, 0}}
serverKey = key.NewMachine()
clientKey = key.NewMachine()
serverErr = make(chan error, 1)
)
go func() {
server, err := Server(context.Background(), serverConn, serverKey, nil)
serverErr <- err
_, err = io.WriteString(server, strings.Repeat("a", 14))
serverErr <- err
}()
client, err := Client(context.Background(), clientConn, clientKey, serverKey.Public(), testProtocolVersion)
if err != nil {
t.Fatalf("client handshake failed: %v", err)
}
// The server shouldn't fail, because the tampering took place
// in its response.
if err := <-serverErr; err != nil {
t.Fatalf("server handshake failed: %v", err)
}
// The client needs a timeout if the tampering is hitting the length header.
if i == 1 || i == 2 {
client.SetReadDeadline(time.Now().Add(10 * time.Millisecond))
}
var bs [100]byte
n, err := client.Read(bs[:])
if err == nil {
t.Fatal("read succeeded despite tampering")
}
if n != 0 {
t.Fatal("conn yielded some bytes despite tampering")
}
}
// Tamper with every byte of the first client>server transport message.
for i := range 30 {
var (
clientConn, serverRaw = memnet.NewConn("noise", 128000)
serverConn = &readerConn{serverRaw, &tamperReader{serverRaw, 101 + i, 0}}
serverKey = key.NewMachine()
clientKey = key.NewMachine()
serverErr = make(chan error, 1)
)
go func() {
server, err := Server(context.Background(), serverConn, serverKey, nil)
serverErr <- err
var bs [100]byte
// The server needs a timeout if the tampering is hitting the length header.
if i == 1 || i == 2 {
server.SetReadDeadline(time.Now().Add(10 * time.Millisecond))
}
n, err := server.Read(bs[:])
if n != 0 {
panic("server got bytes despite tampering")
} else {
serverErr <- err
}
}()
client, err := Client(context.Background(), clientConn, clientKey, serverKey.Public(), testProtocolVersion)
if err != nil {
t.Fatalf("client handshake failed: %v", err)
}
if err := <-serverErr; err != nil {
t.Fatalf("server handshake failed: %v", err)
}
if _, err := io.WriteString(client, strings.Repeat("a", 14)); err != nil {
t.Fatalf("client>server write failed: %v", err)
}
if err := <-serverErr; err == nil {
t.Fatal("server successfully received bytes despite tampering")
}
}
}
|
