fix: ssh-agent connection on Windows

go.mod

@@ -31,6 +31,7 @@ require (
 	golang.org/x/mod v0.5.1
 	golang.org/x/oauth2 v0.0.0-20211104180415-d3ed0bb246c8
 	golang.org/x/term v0.0.0-20210615171337-6886f2dfbf5b
+	gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce
 	gopkg.in/src-d/go-git.v4 v4.13.1
 	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
 )

go.sum

@@ -1447,6 +1447,8 @@ gopkg.in/inf.v0 v0.9.1/go.mod h1:cWUDdTG/fYaXco+Dcufb5Vnc6Gp2YChqWtbxRZE0mXw=
 gopkg.in/ini.v1 v1.62.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/ini.v1 v1.66.2/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/natefinch/lumberjack.v2 v2.0.0/go.mod h1:l0ndWWf7gzL7RNwBG7wST/UCcT4T24xpD6X8LsfU/+k=
+gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce h1:+JknDZhAj8YMt7GC73Ei8pv4MzjDUNPHgQWJdtMAaDU=
+gopkg.in/natefinch/npipe.v2 v2.0.0-20160621034901-c1b8fa8bdcce/go.mod h1:5AcXVHNjg+BDxry382+8OKon8SEWiKktQR07RKPsv1c=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/square/go-jose.v2 v2.2.2/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=
 gopkg.in/square/go-jose.v2 v2.3.1/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=

internal/sshdialer/posix_test.go

@@ -3,11 +3,23 @@
 
 package sshdialer_test
 
-import "os"
+import (
+	"errors"
+	"net"
+	"os"
+)
 
 func fixupPrivateKeyMod(path string) {
 	err := os.Chmod(path, 0400)
 	if err != nil {
 		panic(err)
 	}
 }
+
+func listen(addr string) (net.Listener, error) {
+	return net.Listen("unix", addr)
+}
+
+func isErrClosed(err error) bool {
+	return errors.Is(err, net.ErrClosed)
+}

internal/sshdialer/ssh_agent_unix.go

@@ -0,0 +1,10 @@
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package sshdialer
+
+import "net"
+
+func dialSSHAgent(addr string) (net.Conn, error) {
+	return net.Dial("unix", addr)
+}

internal/sshdialer/ssh_agent_windows.go

@@ -0,0 +1,15 @@
+package sshdialer
+
+import (
+	"net"
+	"strings"
+
+	"gopkg.in/natefinch/npipe.v2"
+)
+
+func dialSSHAgent(addr string) (net.Conn, error) {
+	if strings.Contains(addr, "\\pipe\\") {
+		return npipe.Dial(addr)
+	}
+	return net.Dial("unix", addr)
+}

internal/sshdialer/ssh_dialer.go

@@ -284,7 +284,7 @@ func getSignersFromAgent() ([]ssh.Signer, error) {
 		var err error
 		var agentSigners []ssh.Signer
 		var agentConn net.Conn
-		agentConn, err = net.Dial("unix", sock)
+		agentConn, err = dialSSHAgent(sock)
 		if err != nil {
 			return nil, fmt.Errorf("failed to connect to ssh-agent's socket: %w", err)
 		}

internal/sshdialer/ssh_dialer_test.go

@@ -770,12 +770,21 @@ func withBadSSHAgent(t *testing.T) func() {
 }
 
 func withSSHAgent(t *testing.T, ag agent.Agent) func() {
+	var err error
 	t.Helper()
-	tmpDirForSocket, err := ioutil.TempDir("", "forAuthSock")
-	th.AssertNil(t, err)
 
-	agentSocketPath := filepath.Join(tmpDirForSocket, "agent.sock")
-	unixListener, err := net.Listen("unix", agentSocketPath)
+	var tmpDirForSocket string
+	var agentSocketPath string
+	if runtime.GOOS == "windows" {
+		agentSocketPath = `\\.\pipe\openssh-ssh-agent-test`
+	} else {
+		tmpDirForSocket, err = ioutil.TempDir("", "forAuthSock")
+		th.AssertNil(t, err)
+
+		agentSocketPath = filepath.Join(tmpDirForSocket, "agent.sock")
+	}
+
+	unixListener, err := listen(agentSocketPath)
 	th.AssertNil(t, err)
 
 	os.Setenv("SSH_AUTH_SOCK", agentSocketPath)
@@ -802,7 +811,7 @@ func withSSHAgent(t *testing.T, ag agent.Agent) func() {
 				}()
 				err := agent.ServeAgent(ag, conn)
 				if err != nil {
-					if !errors.Is(err, net.ErrClosed) {
+					if !isErrClosed(err) {
 						fmt.Fprintf(os.Stderr, "agent.ServeAgent() failed: %v\n", err)
 					}
 				}
@@ -818,12 +827,14 @@ func withSSHAgent(t *testing.T, ag agent.Agent) func() {
 
 		err = <-errChan
 
-		if !errors.Is(err, net.ErrClosed) {
+		if !isErrClosed(err) {
 			t.Fatal(err)
 		}
 		cancel()
 		wg.Wait()
-		os.RemoveAll(tmpDirForSocket)
+		if tmpDirForSocket != "" {
+			os.RemoveAll(tmpDirForSocket)
+		}
 	}
 }
 

internal/sshdialer/windows_test.go

@@ -4,9 +4,13 @@
 package sshdialer_test
 
 import (
+	"errors"
+	"net"
 	"os/user"
+	"strings"
 
 	"github.com/hectane/go-acl"
+	"gopkg.in/natefinch/npipe.v2"
 )
 
 func fixupPrivateKeyMod(path string) {
@@ -25,3 +29,14 @@ func fixupPrivateKeyMod(path string) {
 		panic(err)
 	}
 }
+
+func listen(addr string) (net.Listener, error) {
+	if strings.Contains(addr, "\\pipe\\") {
+		return npipe.Listen(addr)
+	}
+	return net.Listen("unix", addr)
+}
+
+func isErrClosed(err error) bool {
+	return errors.Is(err, net.ErrClosed) || errors.Is(err, npipe.ErrClosed)
+}