connect to echo server

go.mod

@@ -255,6 +255,7 @@ require (
 	go.uber.org/zap/exp v0.3.0 // indirect
 	golang.org/x/exp v0.0.0-20240808152545-0cdaa3abc0fa // indirect
 	golang.org/x/mod v0.21.0 // indirect
+	golang.org/x/term v0.30.0 // indirect
 	golang.org/x/text v0.23.0 // indirect
 	golang.org/x/tools v0.24.0 // indirect
 	google.golang.org/genproto v0.0.0-20241118233622-e639e219e697 // indirect

integration2/ssh_int_test.go

@@ -3,12 +3,16 @@ package ssh
 import (
 	"bytes"
 	"crypto/ed25519"
+	"errors"
+	"io"
 	"strings"
+	"sync"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"golang.org/x/crypto/ssh"
+	"golang.org/x/term"
 
 	"github.com/pomerium/pomerium/config"
 	"github.com/pomerium/pomerium/internal/testenv"
@@ -20,31 +24,40 @@ import (
 func TestSSH(t *testing.T) {
 	clientKey := newSSHKey(t)
 	serverHostKey := newSSHKey(t)
+	userCAKey := newSSHKey(t)
 
 	// ssh client setup
 	var ki scenarios.EmptyKeyboardInteractiveChallenge
 	clientConfig := &ssh.ClientConfig{
 		User: "demo@example",
 		Auth: []ssh.AuthMethod{
-			ssh.PublicKeys(clientKey),
+			ssh.PublicKeys(newSignerFromKey(t, clientKey)),
 			ssh.KeyboardInteractive(ki.Do),
 		},
-		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+		HostKeyCallback: ssh.FixedHostKey(newPublicKey(t, serverHostKey.Public())),
 	}
 
 	// pomerium + upstream setup
 	env := testenv.New(t)
 
 	env.Add(scenarios.NewIDP([]*scenarios.User{{Email: "test@example.com"}}, scenarios.WithEnableDeviceAuth(true)))
-	env.Add(scenarios.SSH(scenarios.SSHConfig{}))
+	env.Add(scenarios.SSH(scenarios.SSHConfig{
+		HostKeys:  []any{serverHostKey},
+		UserCAKey: userCAKey,
+	}))
 	env.Add(&ki)
 
+	userCAPublicKey := newPublicKey(t, userCAKey.Public())
+	certChecker := ssh.CertChecker{
+		IsUserAuthority: func(auth ssh.PublicKey) bool {
+			return bytes.Equal(userCAPublicKey.Marshal(), auth.Marshal())
+		},
+	}
 	up := upstreams.SSH(
-		upstreams.WithHostKeys(serverHostKey),
-		upstreams.WithAuthorizedKey(clientKey.PublicKey(), "demo"),
-		upstreams.WithBannerCallback(func(_ ssh.ConnMetadata) string {
-			return "TEST BANNER"
-		}))
+		upstreams.WithHostKeys(newSignerFromKey(t, serverHostKey)),
+		upstreams.WithPublicKeyCallback(certChecker.Authenticate),
+	)
+	up.SetServerConnCallback(echoShell{t}.handleConnection)
 	r := up.Route().
 		From(env.SubdomainURLWithScheme("example", "ssh")).
 		Policy(func(p *config.Policy) { p.AllowAnyAuthenticatedUser = true })
@@ -63,19 +76,90 @@ func TestSSH(t *testing.T) {
 
 	var b bytes.Buffer
 	sess.Stdout = &b
-	sess.Stdin = strings.NewReader("")
-	sess.Shell()
-	sess.Wait()
+	sess.Stdin = strings.NewReader("hello world\r")
+	require.NoError(t, sess.Shell())
+	require.NoError(t, sess.Wait())
 
-	assert.Equal(t, "TEST BANNER", b.String())
+	assert.Equal(t, "> hello world\r\nhello world\r\n> ", b.String())
 }
 
-// newSSHKey generates and returns a new Ed25519 ssh key.
-func newSSHKey(t *testing.T) ssh.Signer {
+type echoShell struct {
+	t *testing.T
+}
+
+func (sh echoShell) handleConnection(conn *ssh.ServerConn, chans <-chan ssh.NewChannel, reqs <-chan *ssh.Request) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	// Reject any global requests from the client.
+	wg.Add(1)
+	go func() {
+		ssh.DiscardRequests(reqs)
+		wg.Done()
+	}()
+
+	// Accept shell session requests.
+	for newChannel := range chans {
+		if newChannel.ChannelType() != "session" {
+			newChannel.Reject(ssh.UnknownChannelType, "unknown channel type")
+			continue
+		}
+		channel, requests, err := newChannel.Accept()
+		require.NoError(sh.t, err, "echoShell: couldn't accept channel")
+
+		// Acknowledge a 'shell' request.
+		wg.Add(1)
+		go func(in <-chan *ssh.Request) {
+			for req := range in {
+				req.Reply(req.Type == "shell", nil)
+			}
+			wg.Done()
+		}(requests)
+
+		// Simulate a terminal that echoes all input lines.
+		term := term.NewTerminal(channel, "> ")
+
+		wg.Add(1)
+		go func() {
+			defer func() {
+				channel.Close()
+				wg.Done()
+			}()
+			for {
+				line, err := term.ReadLine()
+				if errors.Is(err, io.EOF) {
+					break
+				}
+				require.NoError(sh.t, err, "echoShell: couldn't read line")
+				reply := append([]byte(line), '\n')
+				_, err = term.Write(reply)
+				require.NoError(sh.t, err, "echoShell: couldn't write line")
+			}
+			channel.SendRequest("exit-status", false, make([]byte, 4) /* uint32 0 */)
+		}()
+	}
+}
+
+// newSSHKey generates a new Ed25519 ssh key.
+func newSSHKey(t *testing.T) ed25519.PrivateKey {
 	t.Helper()
 	_, priv, err := ed25519.GenerateKey(nil)
 	require.NoError(t, err)
-	signer, err := ssh.NewSignerFromKey(priv)
+	return priv
+}
+
+// newSignerFromKey is a wrapper around ssh.NewSignerFromKey that will fail on error.
+func newSignerFromKey(t *testing.T, key any) ssh.Signer {
+	t.Helper()
+	signer, err := ssh.NewSignerFromKey(key)
 	require.NoError(t, err)
 	return signer
 }
+
+// newPublicKey is a wrapper around ssh.NewPublicKey that will fail on error.
+func newPublicKey(t *testing.T, key any) ssh.PublicKey {
+	t.Helper()
+	sshkey, err := ssh.NewPublicKey(key)
+	require.NoError(t, err)
+	return sshkey
+}

internal/testenv/upstreams/ssh.go

@@ -203,6 +203,7 @@ func (h *sshUpstream) handleConnection(ctx context.Context, conn net.Conn) {
 // Dial implements SSHUpstream.
 func (h *sshUpstream) Dial(r testenv.Route, config *ssh.ClientConfig) (*ssh.Client, error) {
 	return ssh.Dial("tcp", strings.TrimPrefix(r.URL().Value(), "ssh://"), config)
+	//return ssh.Dial("tcp", h.Env().Config().Options.SSHAddr, config)
 }
 
 // DirectDial implements SSHUpstream.