ssh,tempfork/gliderlabs/ssh: replace github.com/tailscale/golang-x-crypto/ssh with golang.org/x/crypto/ssh

The upstream crypto package now supports sending banners at any time during
authentication, so the Tailscale fork of crypto/ssh is no longer necessary.

github.com/tailscale/golang-x-crypto is still needed for some custom ACME
autocert functionality.

tempfork/gliderlabs is still necessary because of a few other customizations,
mostly related to TTY handling.

Originally implemented in 46fd4e58a2,
which was reverted in b60f6b849a to
keep the change out of v1.80.

Updates #8593

Signed-off-by: Percy Wegmann <percy@tailscale.com>

tempfork/gliderlabs/ssh/agent.go

@@ -7,7 +7,7 @@ import (
 	"path"
 	"sync"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 const (

tempfork/gliderlabs/ssh/context.go

@@ -6,7 +6,7 @@ import (
 	"net"
 	"sync"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 // contextKey is a value for use with context.WithValue. It's used as
@@ -55,8 +55,6 @@ var (
 	// ContextKeyPublicKey is a context key for use with Contexts in this package.
 	// The associated value will be of type PublicKey.
 	ContextKeyPublicKey = &contextKey{"public-key"}
-
-	ContextKeySendAuthBanner = &contextKey{"send-auth-banner"}
 )
 
 // Context is a package specific context interface. It exposes connection
@@ -91,8 +89,6 @@ type Context interface {
 
 	// SetValue allows you to easily write new values into the underlying context.
 	SetValue(key, value interface{})
-
-	SendAuthBanner(banner string) error
 }
 
 type sshContext struct {
@@ -121,7 +117,6 @@ func applyConnMetadata(ctx Context, conn gossh.ConnMetadata) {
 	ctx.SetValue(ContextKeyUser, conn.User())
 	ctx.SetValue(ContextKeyLocalAddr, conn.LocalAddr())
 	ctx.SetValue(ContextKeyRemoteAddr, conn.RemoteAddr())
-	ctx.SetValue(ContextKeySendAuthBanner, conn.SendAuthBanner)
 }
 
 func (ctx *sshContext) SetValue(key, value interface{}) {
@@ -158,7 +153,3 @@ func (ctx *sshContext) LocalAddr() net.Addr {
 func (ctx *sshContext) Permissions() *Permissions {
 	return ctx.Value(ContextKeyPermissions).(*Permissions)
 }
-
-func (ctx *sshContext) SendAuthBanner(msg string) error {
-	return ctx.Value(ContextKeySendAuthBanner).(func(string) error)(msg)
-}

tempfork/gliderlabs/ssh/options.go

@@ -3,7 +3,7 @@ package ssh
 import (
 	"os"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 // PasswordAuth returns a functional option that sets PasswordHandler on the server.

tempfork/gliderlabs/ssh/options_test.go

@@ -8,7 +8,7 @@ import (
 	"sync/atomic"
 	"testing"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 func newTestSessionWithOptions(t *testing.T, srv *Server, cfg *gossh.ClientConfig, options ...Option) (*gossh.Session, *gossh.Client, func()) {

tempfork/gliderlabs/ssh/server.go

@@ -8,7 +8,7 @@ import (
 	"sync"
 	"time"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 // ErrServerClosed is returned by the Server's Serve, ListenAndServe,

tempfork/gliderlabs/ssh/session.go

@@ -9,7 +9,7 @@ import (
 	"sync"
 
 	"github.com/anmitsu/go-shlex"
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 // Session provides access to information about an SSH session and methods

tempfork/gliderlabs/ssh/session_test.go

@@ -9,7 +9,7 @@ import (
 	"net"
 	"testing"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 func (srv *Server) serveOnce(l net.Listener) error {

tempfork/gliderlabs/ssh/ssh.go

@@ -4,7 +4,7 @@ import (
 	"crypto/subtle"
 	"net"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 type Signal string
@@ -105,7 +105,7 @@ type Pty struct {
 	// requested by the client as part of the pty-req. These are outlined as
 	// part of https://datatracker.ietf.org/doc/html/rfc4254#section-8.
 	//
-	// The opcodes are defined as constants in github.com/tailscale/golang-x-crypto/ssh (VINTR,VQUIT,etc.).
+	// The opcodes are defined as constants in golang.org/x/crypto/ssh (VINTR,VQUIT,etc.).
 	// Boolean opcodes have values 0 or 1.
 	Modes gossh.TerminalModes
 }

tempfork/gliderlabs/ssh/tcpip.go

@@ -7,7 +7,7 @@ import (
 	"strconv"
 	"sync"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 const (

tempfork/gliderlabs/ssh/tcpip_test.go

@@ -10,7 +10,7 @@ import (
 	"strings"
 	"testing"
 
-	gossh "github.com/tailscale/golang-x-crypto/ssh"
+	gossh "golang.org/x/crypto/ssh"
 )
 
 var sampleServerResponse = []byte("Hello world")

tempfork/gliderlabs/ssh/util.go

@@ -5,7 +5,7 @@ import (
 	"crypto/rsa"
 	"encoding/binary"
 
-	"github.com/tailscale/golang-x-crypto/ssh"
+	"golang.org/x/crypto/ssh"
 )
 
 func generateSigner() (ssh.Signer, error) {

tempfork/gliderlabs/ssh/wrap.go

@@ -1,6 +1,6 @@
 package ssh
 
-import gossh "github.com/tailscale/golang-x-crypto/ssh"
+import gossh "golang.org/x/crypto/ssh"
 
 // PublicKey is an abstraction of different types of public keys.
 type PublicKey interface {