ssh/certs_test.go - crypto - Git at Google

 // Copyright 2013 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 ssh

 import (
 	"bytes"
 	"crypto/ecdsa"
 	"crypto/elliptic"
 	"crypto/rand"
 	"fmt"
 	"io"
 	"net"
 	"reflect"
 	"testing"
 	"time"
 )

 // Cert generated by ssh-keygen 6.0p1 Debian-4.
 // % ssh-keygen -s ca-key -I test user-key
 const exampleSSHCert = `ssh-rsa-cert-v01@openssh.com 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`

 func TestParseCert(t *testing.T) {
 	authKeyBytes := []byte(exampleSSHCert)

 	key, _, _, rest, err := ParseAuthorizedKey(authKeyBytes)
 	if err != nil {
 		t.Fatalf("ParseAuthorizedKey: %v", err)
 	}
 	if len(rest) > 0 {
 		t.Errorf("rest: got %q, want empty", rest)
 	}

 	if _, ok := key.(*Certificate); !ok {
 		t.Fatalf("got %v (%T), want *Certificate", key, key)
 	}

 	marshaled := MarshalAuthorizedKey(key)
 	// Before comparison, remove the trailing newline that
 	// MarshalAuthorizedKey adds.
 	marshaled = marshaled[:len(marshaled)-1]
 	if !bytes.Equal(authKeyBytes, marshaled) {
 		t.Errorf("marshaled certificate does not match original: got %q, want %q", marshaled, authKeyBytes)
 	}
 }

 // Cert generated by ssh-keygen OpenSSH_6.8p1 OS X 10.10.3
 // % ssh-keygen -s ca -I testcert -O source-address=192.168.1.0/24 -O force-command=/bin/sleep user.pub
 // user.pub key: ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDACh1rt2DXfV3hk6fszSQcQ/rueMId0kVD9U7nl8cfEnFxqOCrNT92g4laQIGl2mn8lsGZfTLg8ksHq3gkvgO3oo/0wHy4v32JeBOHTsN5AL4gfHNEhWeWb50ev47hnTsRIt9P4dxogeUo/hTu7j9+s9lLpEQXCvq6xocXQt0j8MV9qZBBXFLXVT3cWIkSqOdwt/5ZBg+1GSrc7WfCXVWgTk4a20uPMuJPxU4RQwZW6X3+O8Pqo8C3cW0OzZRFP6gUYUKUsTI5WntlS+LAxgw1mZNsozFGdbiOPRnEryE3SRldh9vjDR3tin1fGpA5P7+CEB/bqaXtG3V+F2OkqaMN
 // Critical Options:
 //
 //	force-command /bin/sleep
 //	source-address 192.168.1.0/24
 //
 // Extensions:
 //
 //	permit-X11-forwarding
 //	permit-agent-forwarding
 //	permit-port-forwarding
 //	permit-pty
 //	permit-user-rc
 const exampleSSHCertWithOptions = `ssh-rsa-cert-v01@openssh.com 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`

 func TestParseCertWithOptions(t *testing.T) {
 	opts := map[string]string{
 		"source-address": "192.168.1.0/24",
 		"force-command":  "/bin/sleep",
 	}
 	exts := map[string]string{
 		"permit-X11-forwarding":   "",
 		"permit-agent-forwarding": "",
 		"permit-port-forwarding":  "",
 		"permit-pty":              "",
 		"permit-user-rc":          "",
 	}
 	authKeyBytes := []byte(exampleSSHCertWithOptions)

 	key, _, _, rest, err := ParseAuthorizedKey(authKeyBytes)
 	if err != nil {
 		t.Fatalf("ParseAuthorizedKey: %v", err)
 	}
 	if len(rest) > 0 {
 		t.Errorf("rest: got %q, want empty", rest)
 	}
 	cert, ok := key.(*Certificate)
 	if !ok {
 		t.Fatalf("got %v (%T), want *Certificate", key, key)
 	}
 	if !reflect.DeepEqual(cert.CriticalOptions, opts) {
 		t.Errorf("unexpected critical options - got %v, want %v", cert.CriticalOptions, opts)
 	}
 	if !reflect.DeepEqual(cert.Extensions, exts) {
 		t.Errorf("unexpected Extensions - got %v, want %v", cert.Extensions, exts)
 	}
 	marshaled := MarshalAuthorizedKey(key)
 	// Before comparison, remove the trailing newline that
 	// MarshalAuthorizedKey adds.
 	marshaled = marshaled[:len(marshaled)-1]
 	if !bytes.Equal(authKeyBytes, marshaled) {
 		t.Errorf("marshaled certificate does not match original: got %q, want %q", marshaled, authKeyBytes)
 	}
 }

 func TestValidateCert(t *testing.T) {
 	key, _, _, _, err := ParseAuthorizedKey([]byte(exampleSSHCert))
 	if err != nil {
 		t.Fatalf("ParseAuthorizedKey: %v", err)
 	}
 	validCert, ok := key.(*Certificate)
 	if !ok {
 		t.Fatalf("got %v (%T), want *Certificate", key, key)
 	}
 	checker := CertChecker{}
 	checker.IsUserAuthority = func(k PublicKey) bool {
 		return bytes.Equal(k.Marshal(), validCert.SignatureKey.Marshal())
 	}

 	if err := checker.CheckCert("user", validCert); err != nil {
 		t.Errorf("Unable to validate certificate: %v", err)
 	}
 	invalidCert := &Certificate{
 		Key:          testPublicKeys["rsa"],
 		SignatureKey: testPublicKeys["ecdsa"],
 		ValidBefore:  CertTimeInfinity,
 		Signature:    &Signature{},
 	}
 	if err := checker.CheckCert("user", invalidCert); err == nil {
 		t.Error("Invalid cert signature passed validation")
 	}
 }

 func TestValidateCertTime(t *testing.T) {
 	cert := Certificate{
 		ValidPrincipals: []string{"user"},
 		Key:             testPublicKeys["rsa"],
 		ValidAfter:      50,
 		ValidBefore:     100,
 	}

 	cert.SignCert(rand.Reader, testSigners["ecdsa"])

 	for ts, ok := range map[int64]bool{
 		25:  false,
 		50:  true,
 		99:  true,
 		100: false,
 		125: false,
 	} {
 		checker := CertChecker{
 			Clock: func() time.Time { return time.Unix(ts, 0) },
 		}
 		checker.IsUserAuthority = func(k PublicKey) bool {
 			return bytes.Equal(k.Marshal(),
 				testPublicKeys["ecdsa"].Marshal())
 		}

 		if v := checker.CheckCert("user", &cert); (v == nil) != ok {
 			t.Errorf("Authenticate(%d): %v", ts, v)
 		}
 	}
 }

 // TODO(hanwen): tests for
 //
 // host keys:
 // * fallbacks

 func TestHostKeyCert(t *testing.T) {
 	cert := &Certificate{
 		ValidPrincipals: []string{"hostname", "hostname.domain", "otherhost"},
 		Key:             testPublicKeys["rsa"],
 		ValidBefore:     CertTimeInfinity,
 		CertType:        HostCert,
 	}
 	cert.SignCert(rand.Reader, testSigners["ecdsa"])

 	checker := &CertChecker{
 		IsHostAuthority: func(p PublicKey, addr string) bool {
 			return addr == "hostname:22" && bytes.Equal(testPublicKeys["ecdsa"].Marshal(), p.Marshal())
 		},
 	}

 	certSigner, err := NewCertSigner(cert, testSigners["rsa"])
 	if err != nil {
 		t.Errorf("NewCertSigner: %v", err)
 	}

 	for _, test := range []struct {
 		addr                    string
 		succeed                 bool
 		certSignerAlgorithms    []string // Empty means no algorithm restrictions.
 		clientHostKeyAlgorithms []string
 	}{
 		{addr: "hostname:22", succeed: true},
 		{
 			addr:                    "hostname:22",
 			succeed:                 true,
 			certSignerAlgorithms:    []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
 			clientHostKeyAlgorithms: []string{CertAlgoRSASHA512v01},
 		},
 		{
 			addr:                    "hostname:22",
 			succeed:                 false,
 			certSignerAlgorithms:    []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
 			clientHostKeyAlgorithms: []string{CertAlgoRSAv01},
 		},
 		{
 			addr:                    "hostname:22",
 			succeed:                 false,
 			certSignerAlgorithms:    []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
 			clientHostKeyAlgorithms: []string{KeyAlgoRSASHA512}, // Not a certificate algorithm.
 		},
 		{addr: "otherhost:22", succeed: false}, // The certificate is valid for 'otherhost' as hostname, but we only recognize the authority of the signer for the address 'hostname:22'
 		{addr: "lasthost:22", succeed: false},
 	} {
 		c1, c2, err := netPipe()
 		if err != nil {
 			t.Fatalf("netPipe: %v", err)
 		}
 		defer c1.Close()
 		defer c2.Close()

 		errc := make(chan error)

 		go func() {
 			conf := ServerConfig{
 				NoClientAuth: true,
 			}
 			if len(test.certSignerAlgorithms) > 0 {
 				mas, err := NewSignerWithAlgorithms(certSigner.(AlgorithmSigner), test.certSignerAlgorithms)
 				if err != nil {
 					errc <- err
 					return
 				}
 				conf.AddHostKey(mas)
 			} else {
 				conf.AddHostKey(certSigner)
 			}
 			_, _, _, err := NewServerConn(c1, &conf)
 			errc <- err
 		}()

 		config := &ClientConfig{
 			User:              "user",
 			HostKeyCallback:   checker.CheckHostKey,
 			HostKeyAlgorithms: test.clientHostKeyAlgorithms,
 		}
 		_, _, _, err = NewClientConn(c2, test.addr, config)

 		if (err == nil) != test.succeed {
 			t.Errorf("NewClientConn(%q): %v", test.addr, err)
 		}

 		err = <-errc
 		if (err == nil) != test.succeed {
 			t.Errorf("NewServerConn(%q): %v", test.addr, err)
 		}
 	}
 }

 type legacyRSASigner struct {
 	Signer
 }

 func (s *legacyRSASigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
 	v, ok := s.Signer.(AlgorithmSigner)
 	if !ok {
 		return nil, fmt.Errorf("invalid signer")
 	}
 	return v.SignWithAlgorithm(rand, data, KeyAlgoRSA)
 }

 func TestCertTypes(t *testing.T) {
 	algorithmSigner, ok := testSigners["rsa"].(AlgorithmSigner)
 	if !ok {
 		t.Fatal("rsa test signer does not implement the AlgorithmSigner interface")
 	}
 	multiAlgoSignerSHA256, err := NewSignerWithAlgorithms(algorithmSigner, []string{KeyAlgoRSASHA256})
 	if err != nil {
 		t.Fatalf("unable to create multi algorithm signer SHA256: %v", err)
 	}
 	// Algorithms are in order of preference, we expect rsa-sha2-512 to be used.
 	multiAlgoSignerSHA512, err := NewSignerWithAlgorithms(algorithmSigner, []string{KeyAlgoRSASHA512, KeyAlgoRSASHA256})
 	if err != nil {
 		t.Fatalf("unable to create multi algorithm signer SHA512: %v", err)
 	}

 	var testVars = []struct {
 		name   string
 		signer Signer
 		algo   string
 	}{
 		{CertAlgoECDSA256v01, testSigners["ecdsap256"], ""},
 		{CertAlgoECDSA384v01, testSigners["ecdsap384"], ""},
 		{CertAlgoECDSA521v01, testSigners["ecdsap521"], ""},
 		{CertAlgoED25519v01, testSigners["ed25519"], ""},
 		{CertAlgoRSAv01, testSigners["rsa"], KeyAlgoRSASHA256},
 		{"legacyRSASigner", &legacyRSASigner{testSigners["rsa"]}, KeyAlgoRSA},
 		{"multiAlgoRSASignerSHA256", multiAlgoSignerSHA256, KeyAlgoRSASHA256},
 		{"multiAlgoRSASignerSHA512", multiAlgoSignerSHA512, KeyAlgoRSASHA512},
 		{CertAlgoDSAv01, testSigners["dsa"], ""},
 	}

 	k, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
 	if err != nil {
 		t.Fatalf("error generating host key: %v", err)
 	}

 	signer, err := NewSignerFromKey(k)
 	if err != nil {
 		t.Fatalf("error generating signer for ssh listener: %v", err)
 	}

 	conf := &ServerConfig{
 		PublicKeyCallback: func(c ConnMetadata, k PublicKey) (*Permissions, error) {
 			return new(Permissions), nil
 		},
 	}
 	conf.AddHostKey(signer)

 	for _, m := range testVars {
 		t.Run(m.name, func(t *testing.T) {

 			c1, c2, err := netPipe()
 			if err != nil {
 				t.Fatalf("netPipe: %v", err)
 			}
 			defer c1.Close()
 			defer c2.Close()

 			go NewServerConn(c1, conf)

 			priv := m.signer
 			if err != nil {
 				t.Fatalf("error generating ssh pubkey: %v", err)
 			}

 			cert := &Certificate{
 				CertType: UserCert,
 				Key:      priv.PublicKey(),
 			}
 			cert.SignCert(rand.Reader, priv)

 			certSigner, err := NewCertSigner(cert, priv)
 			if err != nil {
 				t.Fatalf("error generating cert signer: %v", err)
 			}

 			if m.algo != "" && cert.Signature.Format != m.algo {
 				t.Errorf("expected %q signature format, got %q", m.algo, cert.Signature.Format)
 			}

 			config := &ClientConfig{
 				User:            "user",
 				HostKeyCallback: func(h string, r net.Addr, k PublicKey) error { return nil },
 				Auth:            []AuthMethod{PublicKeys(certSigner)},
 			}

 			_, _, _, err = NewClientConn(c2, "", config)
 			if err != nil {
 				t.Fatalf("error connecting: %v", err)
 			}
 		})
 	}
 }

 func TestCertSignWithMultiAlgorithmSigner(t *testing.T) {
 	type testcase struct {
 		sigAlgo    string
 		algorithms []string
 	}
 	cases := []testcase{
 		{
 			sigAlgo:    KeyAlgoRSA,
 			algorithms: []string{KeyAlgoRSA, KeyAlgoRSASHA512},
 		},
 		{
 			sigAlgo:    KeyAlgoRSASHA256,
 			algorithms: []string{KeyAlgoRSASHA256, KeyAlgoRSA, KeyAlgoRSASHA512},
 		},
 		{
 			sigAlgo:    KeyAlgoRSASHA512,
 			algorithms: []string{KeyAlgoRSASHA512, KeyAlgoRSASHA256},
 		},
 	}

 	cert := &Certificate{
 		Key:         testPublicKeys["rsa"],
 		ValidBefore: CertTimeInfinity,
 		CertType:    UserCert,
 	}

 	for _, c := range cases {
 		t.Run(c.sigAlgo, func(t *testing.T) {
 			signer, err := NewSignerWithAlgorithms(testSigners["rsa"].(AlgorithmSigner), c.algorithms)
 			if err != nil {
 				t.Fatalf("NewSignerWithAlgorithms error: %v", err)
 			}
 			if err := cert.SignCert(rand.Reader, signer); err != nil {
 				t.Fatalf("SignCert error: %v", err)
 			}
 			if cert.Signature.Format != c.sigAlgo {
 				t.Fatalf("got signature format %q, want %q", cert.Signature.Format, c.sigAlgo)
 			}
 		})
 	}
 }
	// Copyright 2013 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 ssh

	import (
	"bytes"
	"crypto/ecdsa"
	"crypto/elliptic"
	"crypto/rand"
	"fmt"
	"io"
	"net"
	"reflect"
	"testing"
	"time"
	)

	// Cert generated by ssh-keygen 6.0p1 Debian-4.
	// % ssh-keygen -s ca-key -I test user-key
	const exampleSSHCert = `ssh-rsa-cert-v01@openssh.com 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`

	func TestParseCert(t *testing.T) {
	authKeyBytes := []byte(exampleSSHCert)

	key, _, _, rest, err := ParseAuthorizedKey(authKeyBytes)
	if err != nil {
	t.Fatalf("ParseAuthorizedKey: %v", err)
	}
	if len(rest) > 0 {
	t.Errorf("rest: got %q, want empty", rest)
	}

	if _, ok := key.(*Certificate); !ok {
	t.Fatalf("got %v (%T), want *Certificate", key, key)
	}

	marshaled := MarshalAuthorizedKey(key)
	// Before comparison, remove the trailing newline that
	// MarshalAuthorizedKey adds.
	marshaled = marshaled[:len(marshaled)-1]
	if !bytes.Equal(authKeyBytes, marshaled) {
	t.Errorf("marshaled certificate does not match original: got %q, want %q", marshaled, authKeyBytes)
	}
	}

	// Cert generated by ssh-keygen OpenSSH_6.8p1 OS X 10.10.3
	// % ssh-keygen -s ca -I testcert -O source-address=192.168.1.0/24 -O force-command=/bin/sleep user.pub
	// user.pub key: ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDACh1rt2DXfV3hk6fszSQcQ/rueMId0kVD9U7nl8cfEnFxqOCrNT92g4laQIGl2mn8lsGZfTLg8ksHq3gkvgO3oo/0wHy4v32JeBOHTsN5AL4gfHNEhWeWb50ev47hnTsRIt9P4dxogeUo/hTu7j9+s9lLpEQXCvq6xocXQt0j8MV9qZBBXFLXVT3cWIkSqOdwt/5ZBg+1GSrc7WfCXVWgTk4a20uPMuJPxU4RQwZW6X3+O8Pqo8C3cW0OzZRFP6gUYUKUsTI5WntlS+LAxgw1mZNsozFGdbiOPRnEryE3SRldh9vjDR3tin1fGpA5P7+CEB/bqaXtG3V+F2OkqaMN
	// Critical Options:
	//
	// force-command /bin/sleep
	// source-address 192.168.1.0/24
	//
	// Extensions:
	//
	// permit-X11-forwarding
	// permit-agent-forwarding
	// permit-port-forwarding
	// permit-pty
	// permit-user-rc
	const exampleSSHCertWithOptions = `ssh-rsa-cert-v01@openssh.com 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`

	func TestParseCertWithOptions(t *testing.T) {
	opts := map[string]string{
	"source-address": "192.168.1.0/24",
	"force-command": "/bin/sleep",
	}
	exts := map[string]string{
	"permit-X11-forwarding": "",
	"permit-agent-forwarding": "",
	"permit-port-forwarding": "",
	"permit-pty": "",
	"permit-user-rc": "",
	}
	authKeyBytes := []byte(exampleSSHCertWithOptions)

	key, _, _, rest, err := ParseAuthorizedKey(authKeyBytes)
	if err != nil {
	t.Fatalf("ParseAuthorizedKey: %v", err)
	}
	if len(rest) > 0 {
	t.Errorf("rest: got %q, want empty", rest)
	}
	cert, ok := key.(*Certificate)
	if !ok {
	t.Fatalf("got %v (%T), want *Certificate", key, key)
	}
	if !reflect.DeepEqual(cert.CriticalOptions, opts) {
	t.Errorf("unexpected critical options - got %v, want %v", cert.CriticalOptions, opts)
	}
	if !reflect.DeepEqual(cert.Extensions, exts) {
	t.Errorf("unexpected Extensions - got %v, want %v", cert.Extensions, exts)
	}
	marshaled := MarshalAuthorizedKey(key)
	// Before comparison, remove the trailing newline that
	// MarshalAuthorizedKey adds.
	marshaled = marshaled[:len(marshaled)-1]
	if !bytes.Equal(authKeyBytes, marshaled) {
	t.Errorf("marshaled certificate does not match original: got %q, want %q", marshaled, authKeyBytes)
	}
	}

	func TestValidateCert(t *testing.T) {
	key, _, _, _, err := ParseAuthorizedKey([]byte(exampleSSHCert))
	if err != nil {
	t.Fatalf("ParseAuthorizedKey: %v", err)
	}
	validCert, ok := key.(*Certificate)
	if !ok {
	t.Fatalf("got %v (%T), want *Certificate", key, key)
	}
	checker := CertChecker{}
	checker.IsUserAuthority = func(k PublicKey) bool {
	return bytes.Equal(k.Marshal(), validCert.SignatureKey.Marshal())
	}

	if err := checker.CheckCert("user", validCert); err != nil {
	t.Errorf("Unable to validate certificate: %v", err)
	}
	invalidCert := &Certificate{
	Key: testPublicKeys["rsa"],
	SignatureKey: testPublicKeys["ecdsa"],
	ValidBefore: CertTimeInfinity,
	Signature: &Signature{},
	}
	if err := checker.CheckCert("user", invalidCert); err == nil {
	t.Error("Invalid cert signature passed validation")
	}
	}

	func TestValidateCertTime(t *testing.T) {
	cert := Certificate{
	ValidPrincipals: []string{"user"},
	Key: testPublicKeys["rsa"],
	ValidAfter: 50,
	ValidBefore: 100,
	}

	cert.SignCert(rand.Reader, testSigners["ecdsa"])

	for ts, ok := range map[int64]bool{
	25: false,
	50: true,
	99: true,
	100: false,
	125: false,
	} {
	checker := CertChecker{
	Clock: func() time.Time { return time.Unix(ts, 0) },
	}
	checker.IsUserAuthority = func(k PublicKey) bool {
	return bytes.Equal(k.Marshal(),
	testPublicKeys["ecdsa"].Marshal())
	}

	if v := checker.CheckCert("user", &cert); (v == nil) != ok {
	t.Errorf("Authenticate(%d): %v", ts, v)
	}
	}
	}

	// TODO(hanwen): tests for
	//
	// host keys:
	// * fallbacks

	func TestHostKeyCert(t *testing.T) {
	cert := &Certificate{
	ValidPrincipals: []string{"hostname", "hostname.domain", "otherhost"},
	Key: testPublicKeys["rsa"],
	ValidBefore: CertTimeInfinity,
	CertType: HostCert,
	}
	cert.SignCert(rand.Reader, testSigners["ecdsa"])

	checker := &CertChecker{
	IsHostAuthority: func(p PublicKey, addr string) bool {
	return addr == "hostname:22" && bytes.Equal(testPublicKeys["ecdsa"].Marshal(), p.Marshal())
	},
	}

	certSigner, err := NewCertSigner(cert, testSigners["rsa"])
	if err != nil {
	t.Errorf("NewCertSigner: %v", err)
	}

	for _, test := range []struct {
	addr string
	succeed bool
	certSignerAlgorithms []string // Empty means no algorithm restrictions.
	clientHostKeyAlgorithms []string
	}{
	{addr: "hostname:22", succeed: true},
	{
	addr: "hostname:22",
	succeed: true,
	certSignerAlgorithms: []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
	clientHostKeyAlgorithms: []string{CertAlgoRSASHA512v01},
	},
	{
	addr: "hostname:22",
	succeed: false,
	certSignerAlgorithms: []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
	clientHostKeyAlgorithms: []string{CertAlgoRSAv01},
	},
	{
	addr: "hostname:22",
	succeed: false,
	certSignerAlgorithms: []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512},
	clientHostKeyAlgorithms: []string{KeyAlgoRSASHA512}, // Not a certificate algorithm.
	},
	{addr: "otherhost:22", succeed: false}, // The certificate is valid for 'otherhost' as hostname, but we only recognize the authority of the signer for the address 'hostname:22'
	{addr: "lasthost:22", succeed: false},
	} {
	c1, c2, err := netPipe()
	if err != nil {
	t.Fatalf("netPipe: %v", err)
	}
	defer c1.Close()
	defer c2.Close()

	errc := make(chan error)

	go func() {
	conf := ServerConfig{
	NoClientAuth: true,
	}
	if len(test.certSignerAlgorithms) > 0 {
	mas, err := NewSignerWithAlgorithms(certSigner.(AlgorithmSigner), test.certSignerAlgorithms)
	if err != nil {
	errc <- err
	return
	}
	conf.AddHostKey(mas)
	} else {
	conf.AddHostKey(certSigner)
	}
	_, _, _, err := NewServerConn(c1, &conf)
	errc <- err
	}()

	config := &ClientConfig{
	User: "user",
	HostKeyCallback: checker.CheckHostKey,
	HostKeyAlgorithms: test.clientHostKeyAlgorithms,
	}
	_, _, _, err = NewClientConn(c2, test.addr, config)

	if (err == nil) != test.succeed {
	t.Errorf("NewClientConn(%q): %v", test.addr, err)
	}

	err = <-errc
	if (err == nil) != test.succeed {
	t.Errorf("NewServerConn(%q): %v", test.addr, err)
	}
	}
	}

	type legacyRSASigner struct {
	Signer
	}

	func (s legacyRSASigner) Sign(rand io.Reader, data []byte) (Signature, error) {
	v, ok := s.Signer.(AlgorithmSigner)
	if !ok {
	return nil, fmt.Errorf("invalid signer")
	}
	return v.SignWithAlgorithm(rand, data, KeyAlgoRSA)
	}

	func TestCertTypes(t *testing.T) {
	algorithmSigner, ok := testSigners["rsa"].(AlgorithmSigner)
	if !ok {
	t.Fatal("rsa test signer does not implement the AlgorithmSigner interface")
	}
	multiAlgoSignerSHA256, err := NewSignerWithAlgorithms(algorithmSigner, []string{KeyAlgoRSASHA256})
	if err != nil {
	t.Fatalf("unable to create multi algorithm signer SHA256: %v", err)
	}
	// Algorithms are in order of preference, we expect rsa-sha2-512 to be used.
	multiAlgoSignerSHA512, err := NewSignerWithAlgorithms(algorithmSigner, []string{KeyAlgoRSASHA512, KeyAlgoRSASHA256})
	if err != nil {
	t.Fatalf("unable to create multi algorithm signer SHA512: %v", err)
	}

	var testVars = []struct {
	name string
	signer Signer
	algo string
	}{
	{CertAlgoECDSA256v01, testSigners["ecdsap256"], ""},
	{CertAlgoECDSA384v01, testSigners["ecdsap384"], ""},
	{CertAlgoECDSA521v01, testSigners["ecdsap521"], ""},
	{CertAlgoED25519v01, testSigners["ed25519"], ""},
	{CertAlgoRSAv01, testSigners["rsa"], KeyAlgoRSASHA256},
	{"legacyRSASigner", &legacyRSASigner{testSigners["rsa"]}, KeyAlgoRSA},
	{"multiAlgoRSASignerSHA256", multiAlgoSignerSHA256, KeyAlgoRSASHA256},
	{"multiAlgoRSASignerSHA512", multiAlgoSignerSHA512, KeyAlgoRSASHA512},
	{CertAlgoDSAv01, testSigners["dsa"], ""},
	}

	k, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
	if err != nil {
	t.Fatalf("error generating host key: %v", err)
	}

	signer, err := NewSignerFromKey(k)
	if err != nil {
	t.Fatalf("error generating signer for ssh listener: %v", err)
	}

	conf := &ServerConfig{
	PublicKeyCallback: func(c ConnMetadata, k PublicKey) (*Permissions, error) {
	return new(Permissions), nil
	},
	}
	conf.AddHostKey(signer)

	for _, m := range testVars {
	t.Run(m.name, func(t *testing.T) {

	c1, c2, err := netPipe()
	if err != nil {
	t.Fatalf("netPipe: %v", err)
	}
	defer c1.Close()
	defer c2.Close()

	go NewServerConn(c1, conf)

	priv := m.signer
	if err != nil {
	t.Fatalf("error generating ssh pubkey: %v", err)
	}

	cert := &Certificate{
	CertType: UserCert,
	Key: priv.PublicKey(),
	}
	cert.SignCert(rand.Reader, priv)

	certSigner, err := NewCertSigner(cert, priv)
	if err != nil {
	t.Fatalf("error generating cert signer: %v", err)
	}

	if m.algo != "" && cert.Signature.Format != m.algo {
	t.Errorf("expected %q signature format, got %q", m.algo, cert.Signature.Format)
	}

	config := &ClientConfig{
	User: "user",
	HostKeyCallback: func(h string, r net.Addr, k PublicKey) error { return nil },
	Auth: []AuthMethod{PublicKeys(certSigner)},
	}

	_, _, _, err = NewClientConn(c2, "", config)
	if err != nil {
	t.Fatalf("error connecting: %v", err)
	}
	})
	}
	}

	func TestCertSignWithMultiAlgorithmSigner(t *testing.T) {
	type testcase struct {
	sigAlgo string
	algorithms []string
	}
	cases := []testcase{
	{
	sigAlgo: KeyAlgoRSA,
	algorithms: []string{KeyAlgoRSA, KeyAlgoRSASHA512},
	},
	{
	sigAlgo: KeyAlgoRSASHA256,
	algorithms: []string{KeyAlgoRSASHA256, KeyAlgoRSA, KeyAlgoRSASHA512},
	},
	{
	sigAlgo: KeyAlgoRSASHA512,
	algorithms: []string{KeyAlgoRSASHA512, KeyAlgoRSASHA256},
	},
	}

	cert := &Certificate{
	Key: testPublicKeys["rsa"],
	ValidBefore: CertTimeInfinity,
	CertType: UserCert,
	}

	for _, c := range cases {
	t.Run(c.sigAlgo, func(t *testing.T) {
	signer, err := NewSignerWithAlgorithms(testSigners["rsa"].(AlgorithmSigner), c.algorithms)
	if err != nil {
	t.Fatalf("NewSignerWithAlgorithms error: %v", err)
	}
	if err := cert.SignCert(rand.Reader, signer); err != nil {
	t.Fatalf("SignCert error: %v", err)
	}
	if cert.Signature.Format != c.sigAlgo {
	t.Fatalf("got signature format %q, want %q", cert.Signature.Format, c.sigAlgo)
	}
	})
	}
	}