tempfork: temporarily fork gliderlabs/ssh and x/crypto/ssh

While we rearrange/upstream things.

gliderlabs/ssh is forked into tempfork from our prior fork
at be8b7add40

x/crypto/ssh OTOH is forked at
https://github.com/tailscale/golang-x-crypto because it was gnarlier
to vendor with various internal packages, etc.
Its git history shows where it starts (2c7772ba30643b7a2026cbea938420dce7c6384d).

Updates #3802

Change-Id: I546e5cdf831cfc030a6c42557c0ad2c58766c65f
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

tempfork/gliderlabs/ssh/options_test.go

@@ -0,0 +1,112 @@
+//go:build glidertests
+// +build glidertests
+
+package ssh
+
+import (
+	"net"
+	"strings"
+	"sync/atomic"
+	"testing"
+
+	gossh "github.com/tailscale/golang-x-crypto/ssh"
+)
+
+func newTestSessionWithOptions(t *testing.T, srv *Server, cfg *gossh.ClientConfig, options ...Option) (*gossh.Session, *gossh.Client, func()) {
+	for _, option := range options {
+		if err := srv.SetOption(option); err != nil {
+			t.Fatal(err)
+		}
+	}
+	return newTestSession(t, srv, cfg)
+}
+
+func TestPasswordAuth(t *testing.T) {
+	t.Parallel()
+	testUser := "testuser"
+	testPass := "testpass"
+	session, _, cleanup := newTestSessionWithOptions(t, &Server{
+		Handler: func(s Session) {
+			// noop
+		},
+	}, &gossh.ClientConfig{
+		User: testUser,
+		Auth: []gossh.AuthMethod{
+			gossh.Password(testPass),
+		},
+		HostKeyCallback: gossh.InsecureIgnoreHostKey(),
+	}, PasswordAuth(func(ctx Context, password string) bool {
+		if ctx.User() != testUser {
+			t.Fatalf("user = %#v; want %#v", ctx.User(), testUser)
+		}
+		if password != testPass {
+			t.Fatalf("user = %#v; want %#v", password, testPass)
+		}
+		return true
+	}))
+	defer cleanup()
+	if err := session.Run(""); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPasswordAuthBadPass(t *testing.T) {
+	t.Parallel()
+	l := newLocalListener()
+	srv := &Server{Handler: func(s Session) {}}
+	srv.SetOption(PasswordAuth(func(ctx Context, password string) bool {
+		return false
+	}))
+	go srv.serveOnce(l)
+	_, err := gossh.Dial("tcp", l.Addr().String(), &gossh.ClientConfig{
+		User: "testuser",
+		Auth: []gossh.AuthMethod{
+			gossh.Password("testpass"),
+		},
+		HostKeyCallback: gossh.InsecureIgnoreHostKey(),
+	})
+	if err != nil {
+		if !strings.Contains(err.Error(), "unable to authenticate") {
+			t.Fatal(err)
+		}
+	}
+}
+
+type wrappedConn struct {
+	net.Conn
+	written int32
+}
+
+func (c *wrappedConn) Write(p []byte) (n int, err error) {
+	n, err = c.Conn.Write(p)
+	atomic.AddInt32(&(c.written), int32(n))
+	return
+}
+
+func TestConnWrapping(t *testing.T) {
+	t.Parallel()
+	var wrapped *wrappedConn
+	session, _, cleanup := newTestSessionWithOptions(t, &Server{
+		Handler: func(s Session) {
+			// nothing
+		},
+	}, &gossh.ClientConfig{
+		User: "testuser",
+		Auth: []gossh.AuthMethod{
+			gossh.Password("testpass"),
+		},
+		HostKeyCallback: gossh.InsecureIgnoreHostKey(),
+	}, PasswordAuth(func(ctx Context, password string) bool {
+		return true
+	}), WrapConn(func(ctx Context, conn net.Conn) net.Conn {
+		wrapped = &wrappedConn{conn, 0}
+		return wrapped
+	}))
+	defer cleanup()
+	if err := session.Shell(); err != nil {
+		t.Fatal(err)
+	}
+	if atomic.LoadInt32(&(wrapped.written)) == 0 {
+		t.Fatal("wrapped conn not written to")
+	}
+}