diff --git a/ssh/test/server_test.go b/ssh/test/server_test.go new file mode 100644 index 0000000000..e70241bc6e --- /dev/null +++ b/ssh/test/server_test.go @@ -0,0 +1,98 @@ +// Copyright 2023 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package test + +import ( + "net" + + "golang.org/x/crypto/ssh" +) + +type exitStatusMsg struct { + Status uint32 +} + +// goServer is a test Go SSH server that accepts public key and certificate +// authentication and replies with a 0 exit status to any exec request without +// running any commands. +type goTestServer struct { + listener net.Listener + config *ssh.ServerConfig + done <-chan struct{} +} + +func newTestServer(config *ssh.ServerConfig) (*goTestServer, error) { + server := &goTestServer{ + config: config, + } + listener, err := net.Listen("tcp", "127.0.0.1:") + if err != nil { + return nil, err + } + server.listener = listener + done := make(chan struct{}, 1) + server.done = done + go server.acceptConnections(done) + + return server, nil +} + +func (s *goTestServer) port() (string, error) { + _, port, err := net.SplitHostPort(s.listener.Addr().String()) + return port, err +} + +func (s *goTestServer) acceptConnections(done chan<- struct{}) { + defer close(done) + + for { + c, err := s.listener.Accept() + if err != nil { + return + } + _, chans, reqs, err := ssh.NewServerConn(c, s.config) + if err != nil { + return + } + go ssh.DiscardRequests(reqs) + defer c.Close() + + for newChannel := range chans { + if newChannel.ChannelType() != "session" { + newChannel.Reject(ssh.UnknownChannelType, "unknown channel type") + continue + } + + channel, requests, err := newChannel.Accept() + if err != nil { + continue + } + + go func(in <-chan *ssh.Request) { + for req := range in { + ok := false + switch req.Type { + case "exec": + ok = true + go func() { + channel.SendRequest("exit-status", false, ssh.Marshal(&exitStatusMsg{Status: 0})) + channel.Close() + }() + } + if req.WantReply { + req.Reply(ok, nil) + } + } + }(requests) + } + } +} + +func (s *goTestServer) Close() error { + err := s.listener.Close() + // wait for the accept loop to exit + <-s.done + return err +} diff --git a/ssh/test/sshcli_test.go b/ssh/test/sshcli_test.go new file mode 100644 index 0000000000..d3b85d77e2 --- /dev/null +++ b/ssh/test/sshcli_test.go @@ -0,0 +1,96 @@ +// Copyright 2023 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package test + +import ( + "bytes" + "fmt" + "os" + "os/exec" + "path/filepath" + "testing" + + "golang.org/x/crypto/internal/testenv" + "golang.org/x/crypto/ssh" + "golang.org/x/crypto/ssh/testdata" +) + +func sshClient(t *testing.T) string { + if testing.Short() { + t.Skip("Skipping test that executes OpenSSH in -short mode") + } + sshCLI := os.Getenv("SSH_CLI_PATH") + if sshCLI == "" { + sshCLI = "ssh" + } + var err error + sshCLI, err = exec.LookPath(sshCLI) + if err != nil { + t.Skipf("Can't find an ssh(1) client to test against: %v", err) + } + return sshCLI +} + +func TestSSHCLIAuth(t *testing.T) { + sshCLI := sshClient(t) + dir := t.TempDir() + keyPrivPath := filepath.Join(dir, "rsa") + + for fn, content := range map[string][]byte{ + keyPrivPath: testdata.PEMBytes["rsa"], + keyPrivPath + ".pub": ssh.MarshalAuthorizedKey(testPublicKeys["rsa"]), + filepath.Join(dir, "rsa-cert.pub"): testdata.SSHCertificates["rsa-user-testcertificate"], + } { + if err := os.WriteFile(fn, content, 0600); err != nil { + t.Fatalf("WriteFile(%q): %v", fn, err) + } + } + + certChecker := ssh.CertChecker{ + IsUserAuthority: func(k ssh.PublicKey) bool { + return bytes.Equal(k.Marshal(), testPublicKeys["ca"].Marshal()) + }, + UserKeyFallback: func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) { + if conn.User() == "testpubkey" && bytes.Equal(key.Marshal(), testPublicKeys["rsa"].Marshal()) { + return nil, nil + } + + return nil, fmt.Errorf("pubkey for %q not acceptable", conn.User()) + }, + } + + config := &ssh.ServerConfig{ + PublicKeyCallback: certChecker.Authenticate, + } + config.AddHostKey(testSigners["rsa"]) + + server, err := newTestServer(config) + if err != nil { + t.Fatalf("unable to start test server: %v", err) + } + defer server.Close() + + port, err := server.port() + if err != nil { + t.Fatalf("unable to get server port: %v", err) + } + + // test public key authentication. + cmd := testenv.Command(t, sshCLI, "-vvv", "-i", keyPrivPath, "-o", "StrictHostKeyChecking=no", + "-p", port, "testpubkey@127.0.0.1", "true") + out, err := cmd.CombinedOutput() + if err != nil { + t.Fatalf("public key authentication failed, error: %v, command output %q", err, string(out)) + } + // Test SSH user certificate authentication. + // The username must match one of the principals included in the certificate. + // The certificate "rsa-user-testcertificate" has "testcertificate" as principal. + cmd = testenv.Command(t, sshCLI, "-vvv", "-i", keyPrivPath, "-o", "StrictHostKeyChecking=no", + "-p", port, "testcertificate@127.0.0.1", "true") + out, err = cmd.CombinedOutput() + if err != nil { + t.Fatalf("user certificate authentication failed, error: %v, command output %q", err, string(out)) + } +} diff --git a/ssh/testdata/keys.go b/ssh/testdata/keys.go index ad95a81929..69f9eef4de 100644 --- a/ssh/testdata/keys.go +++ b/ssh/testdata/keys.go @@ -195,6 +195,12 @@ var SSHCertificates = map[string][]byte{ "rsa-sha2-256": []byte(`ssh-rsa-cert-v01@openssh.com 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 host.example.com `), "rsa-sha2-512": []byte(`ssh-rsa-cert-v01@openssh.com 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 host.example.com +`), + // Assumes "ca" key above in file named "ca", sign a user cert for "rsa.pub" + // using "testcertificate" as principal: + // + // ssh-keygen -s ca -I username -n testcertificate rsa.pub + "rsa-user-testcertificate": []byte(`ssh-rsa-cert-v01@openssh.com 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 rsa.pub `), }