Update vendor (whatsapp)

11 files changed, 480 insertions, 350 deletions

diff --git a/vendor/golang.org/x/crypto/ssh/certs.go b/vendor/golang.org/x/crypto/ssh/certs.go
index 6605bf64..a69e2249 100644
--- a/vendor/golang.org/x/crypto/ssh/certs.go
+++ b/vendor/golang.org/x/crypto/ssh/certs.go
@@ -14,8 +14,10 @@ import (
 	"time"
 )
 
-// These constants from [PROTOCOL.certkeys] represent the key algorithm names
-// for certificate types supported by this package.
+// Certificate algorithm names from [PROTOCOL.certkeys]. These values can appear
+// in Certificate.Type, PublicKey.Type, and ClientConfig.HostKeyAlgorithms.
+// Unlike key algorithm names, these are not passed to AlgorithmSigner and don't
+// appear in the Signature.Format field.
 const (
 	CertAlgoRSAv01        = "ssh-rsa-cert-v01@openssh.com"
 	CertAlgoDSAv01        = "ssh-dss-cert-v01@openssh.com"
@@ -25,14 +27,21 @@ const (
 	CertAlgoSKECDSA256v01 = "sk-ecdsa-sha2-nistp256-cert-v01@openssh.com"
 	CertAlgoED25519v01    = "ssh-ed25519-cert-v01@openssh.com"
 	CertAlgoSKED25519v01  = "sk-ssh-ed25519-cert-v01@openssh.com"
+
+	// CertAlgoRSASHA256v01 and CertAlgoRSASHA512v01 can't appear as a
+	// Certificate.Type (or PublicKey.Type), but only in
+	// ClientConfig.HostKeyAlgorithms.
+	CertAlgoRSASHA256v01 = "rsa-sha2-256-cert-v01@openssh.com"
+	CertAlgoRSASHA512v01 = "rsa-sha2-512-cert-v01@openssh.com"
 )
 
-// These constants from [PROTOCOL.certkeys] represent additional signature
-// algorithm names for certificate types supported by this package.
 const (
-	CertSigAlgoRSAv01        = "ssh-rsa-cert-v01@openssh.com"
-	CertSigAlgoRSASHA2256v01 = "rsa-sha2-256-cert-v01@openssh.com"
-	CertSigAlgoRSASHA2512v01 = "rsa-sha2-512-cert-v01@openssh.com"
+	// Deprecated: use CertAlgoRSAv01.
+	CertSigAlgoRSAv01 = CertAlgoRSAv01
+	// Deprecated: use CertAlgoRSASHA256v01.
+	CertSigAlgoRSASHA2256v01 = CertAlgoRSASHA256v01
+	// Deprecated: use CertAlgoRSASHA512v01.
+	CertSigAlgoRSASHA2512v01 = CertAlgoRSASHA512v01
 )
 
 // Certificate types distinguish between host and user
@@ -431,10 +440,14 @@ func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
 	}
 	c.SignatureKey = authority.PublicKey()
 
-	if v, ok := authority.(AlgorithmSigner); ok {
-		if v.PublicKey().Type() == KeyAlgoRSA {
-			authority = &rsaSigner{v, SigAlgoRSASHA2512}
+	// Default to KeyAlgoRSASHA512 for ssh-rsa signers.
+	if v, ok := authority.(AlgorithmSigner); ok && v.PublicKey().Type() == KeyAlgoRSA {
+		sig, err := v.SignWithAlgorithm(rand, c.bytesForSigning(), KeyAlgoRSASHA512)
+		if err != nil {
+			return err
 		}
+		c.Signature = sig
+		return nil
 	}
 
 	sig, err := authority.Sign(rand, c.bytesForSigning())
@@ -445,32 +458,40 @@ func (c *Certificate) SignCert(rand io.Reader, authority Signer) error {
 	return nil
 }
 
-// certAlgoNames includes a mapping from signature algorithms to the
-// corresponding certificate signature algorithm. When a key type (such
-// as ED25516) is associated with only one algorithm, the KeyAlgo
-// constant is used instead of the SigAlgo.
-var certAlgoNames = map[string]string{
-	SigAlgoRSA:        CertSigAlgoRSAv01,
-	SigAlgoRSASHA2256: CertSigAlgoRSASHA2256v01,
-	SigAlgoRSASHA2512: CertSigAlgoRSASHA2512v01,
-	KeyAlgoDSA:        CertAlgoDSAv01,
-	KeyAlgoECDSA256:   CertAlgoECDSA256v01,
-	KeyAlgoECDSA384:   CertAlgoECDSA384v01,
-	KeyAlgoECDSA521:   CertAlgoECDSA521v01,
-	KeyAlgoSKECDSA256: CertAlgoSKECDSA256v01,
-	KeyAlgoED25519:    CertAlgoED25519v01,
-	KeyAlgoSKED25519:  CertAlgoSKED25519v01,
+// certKeyAlgoNames is a mapping from known certificate algorithm names to the
+// corresponding public key signature algorithm.
+var certKeyAlgoNames = map[string]string{
+	CertAlgoRSAv01:        KeyAlgoRSA,
+	CertAlgoRSASHA256v01:  KeyAlgoRSASHA256,
+	CertAlgoRSASHA512v01:  KeyAlgoRSASHA512,
+	CertAlgoDSAv01:        KeyAlgoDSA,
+	CertAlgoECDSA256v01:   KeyAlgoECDSA256,
+	CertAlgoECDSA384v01:   KeyAlgoECDSA384,
+	CertAlgoECDSA521v01:   KeyAlgoECDSA521,
+	CertAlgoSKECDSA256v01: KeyAlgoSKECDSA256,
+	CertAlgoED25519v01:    KeyAlgoED25519,
+	CertAlgoSKED25519v01:  KeyAlgoSKED25519,
+}
+
+// underlyingAlgo returns the signature algorithm associated with algo (which is
+// an advertised or negotiated public key or host key algorithm). These are
+// usually the same, except for certificate algorithms.
+func underlyingAlgo(algo string) string {
+	if a, ok := certKeyAlgoNames[algo]; ok {
+		return a
+	}
+	return algo
 }
 
-// certToPrivAlgo returns the underlying algorithm for a certificate algorithm.
-// Panics if a non-certificate algorithm is passed.
-func certToPrivAlgo(algo string) string {
-	for privAlgo, pubAlgo := range certAlgoNames {
-		if pubAlgo == algo {
-			return privAlgo
+// certificateAlgo returns the certificate algorithms that uses the provided
+// underlying signature algorithm.
+func certificateAlgo(algo string) (certAlgo string, ok bool) {
+	for certName, algoName := range certKeyAlgoNames {
+		if algoName == algo {
+			return certName, true
 		}
 	}
-	panic("unknown cert algorithm")
+	return "", false
 }
 
 func (cert *Certificate) bytesForSigning() []byte {
@@ -514,13 +535,13 @@ func (c *Certificate) Marshal() []byte {
 	return result
 }
 
-// Type returns the key name. It is part of the PublicKey interface.
+// Type returns the certificate algorithm name. It is part of the PublicKey interface.
 func (c *Certificate) Type() string {
-	algo, ok := certAlgoNames[c.Key.Type()]
+	certName, ok := certificateAlgo(c.Key.Type())
 	if !ok {
-		panic("unknown cert key type " + c.Key.Type())
+		panic("unknown certificate type for key type " + c.Key.Type())
 	}
-	return algo
+	return certName
 }
 
 // Verify verifies a signature against the certificate's public
diff --git a/vendor/golang.org/x/crypto/ssh/client.go b/vendor/golang.org/x/crypto/ssh/client.go
index ba8621a8..bdc356cb 100644
--- a/vendor/golang.org/x/crypto/ssh/client.go
+++ b/vendor/golang.org/x/crypto/ssh/client.go
@@ -113,25 +113,16 @@ func (c *connection) clientHandshake(dialAddress string, config *ClientConfig) e
 	return c.clientAuthenticate(config)
 }
 
-// verifyHostKeySignature verifies the host key obtained in the key
-// exchange.
+// verifyHostKeySignature verifies the host key obtained in the key exchange.
+// algo is the negotiated algorithm, and may be a certificate type.
 func verifyHostKeySignature(hostKey PublicKey, algo string, result *kexResult) error {
 	sig, rest, ok := parseSignatureBody(result.Signature)
 	if len(rest) > 0 || !ok {
 		return errors.New("ssh: signature parse error")
 	}
 
-	// For keys, underlyingAlgo is exactly algo. For certificates,
-	// we have to look up the underlying key algorithm that SSH
-	// uses to evaluate signatures.
-	underlyingAlgo := algo
-	for sigAlgo, certAlgo := range certAlgoNames {
-		if certAlgo == algo {
-			underlyingAlgo = sigAlgo
-		}
-	}
-	if sig.Format != underlyingAlgo {
-		return fmt.Errorf("ssh: invalid signature algorithm %q, expected %q", sig.Format, underlyingAlgo)
+	if a := underlyingAlgo(algo); sig.Format != a {
+		return fmt.Errorf("ssh: invalid signature algorithm %q, expected %q", sig.Format, a)
 	}
 
 	return hostKey.Verify(result.H, sig)
@@ -237,11 +228,11 @@ type ClientConfig struct {
 	// be used for the connection. If empty, a reasonable default is used.
 	ClientVersion string
 
-	// HostKeyAlgorithms lists the key types that the client will
-	// accept from the server as host key, in order of
+	// HostKeyAlgorithms lists the public key algorithms that the client will
+	// accept from the server for host key authentication, in order of
 	// preference. If empty, a reasonable default is used. Any
-	// string returned from PublicKey.Type method may be used, or
-	// any of the CertAlgoXxxx and KeyAlgoXxxx constants.
+	// string returned from a PublicKey.Type method may be used, or
+	// any of the CertAlgo and KeyAlgo constants.
 	HostKeyAlgorithms []string
 
 	// Timeout is the maximum amount of time for the TCP connection to establish.
diff --git a/vendor/golang.org/x/crypto/ssh/client_auth.go b/vendor/golang.org/x/crypto/ssh/client_auth.go
index c611aeb6..409b5ea1 100644
--- a/vendor/golang.org/x/crypto/ssh/client_auth.go
+++ b/vendor/golang.org/x/crypto/ssh/client_auth.go
@@ -9,6 +9,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"strings"
 )
 
 type authResult int
@@ -29,6 +30,33 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	if err != nil {
 		return err
 	}
+	// The server may choose to send a SSH_MSG_EXT_INFO at this point (if we
+	// advertised willingness to receive one, which we always do) or not. See
+	// RFC 8308, Section 2.4.
+	extensions := make(map[string][]byte)
+	if len(packet) > 0 && packet[0] == msgExtInfo {
+		var extInfo extInfoMsg
+		if err := Unmarshal(packet, &extInfo); err != nil {
+			return err
+		}
+		payload := extInfo.Payload
+		for i := uint32(0); i < extInfo.NumExtensions; i++ {
+			name, rest, ok := parseString(payload)
+			if !ok {
+				return parseError(msgExtInfo)
+			}
+			value, rest, ok := parseString(rest)
+			if !ok {
+				return parseError(msgExtInfo)
+			}
+			extensions[string(name)] = value
+			payload = rest
+		}
+		packet, err = c.transport.readPacket()
+		if err != nil {
+			return err
+		}
+	}
 	var serviceAccept serviceAcceptMsg
 	if err := Unmarshal(packet, &serviceAccept); err != nil {
 		return err
@@ -41,7 +69,7 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 
 	sessionID := c.transport.getSessionID()
 	for auth := AuthMethod(new(noneAuth)); auth != nil; {
-		ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand)
+		ok, methods, err := auth.auth(sessionID, config.User, c.transport, config.Rand, extensions)
 		if err != nil {
 			return err
 		}
@@ -93,7 +121,7 @@ type AuthMethod interface {
 	// If authentication is not successful, a []string of alternative
 	// method names is returned. If the slice is nil, it will be ignored
 	// and the previous set of possible methods will be reused.
-	auth(session []byte, user string, p packetConn, rand io.Reader) (authResult, []string, error)
+	auth(session []byte, user string, p packetConn, rand io.Reader, extensions map[string][]byte) (authResult, []string, error)
 
 	// method returns the RFC 4252 method name.
 	method() string
@@ -102,7 +130,7 @@ type AuthMethod interface {
 // "none" authentication, RFC 4252 section 5.2.
 type noneAuth int
 
-func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
+func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
 	if err := c.writePacket(Marshal(&userAuthRequestMsg{
 		User:    user,
 		Service: serviceSSH,
@@ -122,7 +150,7 @@ func (n *noneAuth) method() string {
 // a function call, e.g. by prompting the user.
 type passwordCallback func() (password string, err error)
 
-func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
+func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
 	type passwordAuthMsg struct {
 		User     string `sshtype:"50"`
 		Service  string
@@ -189,7 +217,46 @@ func (cb publicKeyCallback) method() string {
 	return "publickey"
 }
 
-func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
+func pickSignatureAlgorithm(signer Signer, extensions map[string][]byte) (as AlgorithmSigner, algo string) {
+	keyFormat := signer.PublicKey().Type()
+
+	// Like in sendKexInit, if the public key implements AlgorithmSigner we
+	// assume it supports all algorithms, otherwise only the key format one.
+	as, ok := signer.(AlgorithmSigner)
+	if !ok {
+		return algorithmSignerWrapper{signer}, keyFormat
+	}
+
+	extPayload, ok := extensions["server-sig-algs"]
+	if !ok {
+		// If there is no "server-sig-algs" extension, fall back to the key
+		// format algorithm.
+		return as, keyFormat
+	}
+
+	// The server-sig-algs extension only carries underlying signature
+	// algorithm, but we are trying to select a protocol-level public key
+	// algorithm, which might be a certificate type. Extend the list of server
+	// supported algorithms to include the corresponding certificate algorithms.
+	serverAlgos := strings.Split(string(extPayload), ",")
+	for _, algo := range serverAlgos {
+		if certAlgo, ok := certificateAlgo(algo); ok {
+			serverAlgos = append(serverAlgos, certAlgo)
+		}
+	}
+
+	keyAlgos := algorithmsForKeyFormat(keyFormat)
+	algo, err := findCommon("public key signature algorithm", keyAlgos, serverAlgos)
+	if err != nil {
+		// If there is no overlap, try the key anyway with the key format
+		// algorithm, to support servers that fail to list all supported
+		// algorithms.
+		return as, keyFormat
+	}
+	return as, algo
+}
+
+func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader, extensions map[string][]byte) (authResult, []string, error) {
 	// Authentication is performed by sending an enquiry to test if a key is
 	// acceptable to the remote. If the key is acceptable, the client will
 	// attempt to authenticate with the valid key.  If not the client will repeat
@@ -201,7 +268,10 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 	}
 	var methods []string
 	for _, signer := range signers {
-		ok, err := validateKey(signer.PublicKey(), user, c)
+		pub := signer.PublicKey()
+		as, algo := pickSignatureAlgorithm(signer, extensions)
+
+		ok, err := validateKey(pub, algo, user, c)
 		if err != nil {
 			return authFailure, nil, err
 		}
@@ -209,13 +279,13 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 			continue
 		}
 
-		pub := signer.PublicKey()
 		pubKey := pub.Marshal()
-		sign, err := signer.Sign(rand, buildDataSignedForAuth(session, userAuthRequestMsg{
+		data := buildDataSignedForAuth(session, userAuthRequestMsg{
 			User:    user,
 			Service: serviceSSH,
 			Method:  cb.method(),
-		}, []byte(pub.Type()), pubKey))
+		}, algo, pubKey)
+		sign, err := as.SignWithAlgorithm(rand, data, underlyingAlgo(algo))
 		if err != nil {
 			return authFailure, nil, err
 		}
@@ -229,7 +299,7 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 			Service:  serviceSSH,
 			Method:   cb.method(),
 			HasSig:   true,
-			Algoname: pub.Type(),
+			Algoname: algo,
 			PubKey:   pubKey,
 			Sig:      sig,
 		}
@@ -266,26 +336,25 @@ func containsMethod(methods []string, method string) bool {
 }
 
 // validateKey validates the key provided is acceptable to the server.
-func validateKey(key PublicKey, user string, c packetConn) (bool, error) {
+func validateKey(key PublicKey, algo string, user string, c packetConn) (bool, error) {
 	pubKey := key.Marshal()
 	msg := publickeyAuthMsg{
 		User:     user,
 		Service:  serviceSSH,
 		Method:   "publickey",
 		HasSig:   false,
-		Algoname: key.Type(),
+		Algoname: algo,
 		PubKey:   pubKey,
 	}
 	if err := c.writePacket(Marshal(&msg)); err != nil {
 		return false, err
 	}
 
-	return confirmKeyAck(key, c)
+	return confirmKeyAck(key, algo, c)
 }
 
-func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
+func confirmKeyAck(key PublicKey, algo string, c packetConn) (bool, error) {
 	pubKey := key.Marshal()
-	algoname := key.Type()
 
 	for {
 		packet, err := c.readPacket()
@@ -302,14 +371,14 @@ func confirmKeyAck(key PublicKey, c packetConn) (bool, error) {
 			if err := Unmarshal(packet, &msg); err != nil {
 				return false, err
 			}
-			if msg.Algo != algoname || !bytes.Equal(msg.PubKey, pubKey) {
+			if msg.Algo != algo || !bytes.Equal(msg.PubKey, pubKey) {
 				return false, nil
 			}
 			return true, nil
 		case msgUserAuthFailure:
 			return false, nil
 		default:
-			return false, unexpectedMessageError(msgUserAuthSuccess, packet[0])
+			return false, unexpectedMessageError(msgUserAuthPubKeyOk, packet[0])
 		}
 	}
 }
@@ -330,6 +399,7 @@ func PublicKeysCallback(getSigners func() (signers []Signer, err error)) AuthMet
 // along with a list of remaining authentication methods to try next and
 // an error if an unexpected response was received.
 func handleAuthResponse(c packetConn) (authResult, []string, error) {
+	gotMsgExtInfo := false
 	for {
 		packet, err := c.readPacket()
 		if err != nil {
@@ -341,6 +411,12 @@ func handleAuthResponse(c packetConn) (authResult, []string, error) {
 			if err := handleBannerResponse(c, packet); err != nil {
 				return authFailure, nil, err
 			}
+		case msgExtInfo:
+			// Ignore post-authentication RFC 8308 extensions, once.
+			if gotMsgExtInfo {
+				return authFailure, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
+			}
+			gotMsgExtInfo = true
 		case msgUserAuthFailure:
 			var msg userAuthFailureMsg
 			if err := Unmarshal(packet, &msg); err != nil {
@@ -380,10 +456,10 @@ func handleBannerResponse(c packetConn, packet []byte) error {
 // disabling echoing (e.g. for passwords), and return all the answers.
 // Challenge may be called multiple times in a single session. After
 // successful authentication, the server may send a challenge with no
-// questions, for which the user and instruction messages should be
+// questions, for which the name and instruction messages should be
 // printed.  RFC 4256 section 3.3 details how the UI should behave for
 // both CLI and GUI environments.
-type KeyboardInteractiveChallenge func(user, instruction string, questions []string, echos []bool) (answers []string, err error)
+type KeyboardInteractiveChallenge func(name, instruction string, questions []string, echos []bool) (answers []string, err error)
 
 // KeyboardInteractive returns an AuthMethod using a prompt/response
 // sequence controlled by the server.
@@ -395,7 +471,7 @@ func (cb KeyboardInteractiveChallenge) method() string {
 	return "keyboard-interactive"
 }
 
-func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
+func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
 	type initiateMsg struct {
 		User       string `sshtype:"50"`
 		Service    string
@@ -412,6 +488,7 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		return authFailure, nil, err
 	}
 
+	gotMsgExtInfo := false
 	for {
 		packet, err := c.readPacket()
 		if err != nil {
@@ -425,6 +502,13 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 				return authFailure, nil, err
 			}
 			continue
+		case msgExtInfo:
+			// Ignore post-authentication RFC 8308 extensions, once.
+			if gotMsgExtInfo {
+				return authFailure, nil, unexpectedMessageError(msgUserAuthInfoRequest, packet[0])
+			}
+			gotMsgExtInfo = true
+			continue
 		case msgUserAuthInfoRequest:
 			// OK
 		case msgUserAuthFailure:
@@ -465,7 +549,7 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 			return authFailure, nil, errors.New("ssh: extra data following keyboard-interactive pairs")
 		}
 
-		answers, err := cb(msg.User, msg.Instruction, prompts, echos)
+		answers, err := cb(msg.Name, msg.Instruction, prompts, echos)
 		if err != nil {
 			return authFailure, nil, err
 		}
@@ -497,9 +581,9 @@ type retryableAuthMethod struct {
 	maxTries   int
 }
 
-func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader) (ok authResult, methods []string, err error) {
+func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader, extensions map[string][]byte) (ok authResult, methods []string, err error) {
 	for i := 0; r.maxTries <= 0 || i < r.maxTries; i++ {
-		ok, methods, err = r.authMethod.auth(session, user, c, rand)
+		ok, methods, err = r.authMethod.auth(session, user, c, rand, extensions)
 		if ok != authFailure || err != nil { // either success, partial success or error terminate
 			return ok, methods, err
 		}
@@ -542,7 +626,7 @@ type gssAPIWithMICCallback struct {
 	target       string
 }
 
-func (g *gssAPIWithMICCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
+func (g *gssAPIWithMICCallback) auth(session []byte, user string, c packetConn, rand io.Reader, _ map[string][]byte) (authResult, []string, error) {
 	m := &userAuthRequestMsg{
 		User:    user,
 		Service: serviceSSH,
diff --git a/vendor/golang.org/x/crypto/ssh/common.go b/vendor/golang.org/x/crypto/ssh/common.go
index 5ae22757..2a47a61d 100644
--- a/vendor/golang.org/x/crypto/ssh/common.go
+++ b/vendor/golang.org/x/crypto/ssh/common.go
@@ -44,11 +44,11 @@ var preferredCiphers = []string{
 // supportedKexAlgos specifies the supported key-exchange algorithms in
 // preference order.
 var supportedKexAlgos = []string{
-	kexAlgoCurve25519SHA256,
+	kexAlgoCurve25519SHA256, kexAlgoCurve25519SHA256LibSSH,
 	// P384 and P521 are not constant-time yet, but since we don't
 	// reuse ephemeral keys, using them for ECDH should be OK.
 	kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521,
-	kexAlgoDH14SHA1, kexAlgoDH1SHA1,
+	kexAlgoDH14SHA256, kexAlgoDH14SHA1, kexAlgoDH1SHA1,
 }
 
 // serverForbiddenKexAlgos contains key exchange algorithms, that are forbidden
@@ -61,21 +61,21 @@ var serverForbiddenKexAlgos = map[string]struct{}{
 // preferredKexAlgos specifies the default preference for key-exchange algorithms
 // in preference order.
 var preferredKexAlgos = []string{
-	kexAlgoCurve25519SHA256,
+	kexAlgoCurve25519SHA256, kexAlgoCurve25519SHA256LibSSH,
 	kexAlgoECDH256, kexAlgoECDH384, kexAlgoECDH521,
-	kexAlgoDH14SHA1,
+	kexAlgoDH14SHA256, kexAlgoDH14SHA1,
 }
 
 // supportedHostKeyAlgos specifies the supported host-key algorithms (i.e. methods
 // of authenticating servers) in preference order.
 var supportedHostKeyAlgos = []string{
-	CertSigAlgoRSASHA2512v01, CertSigAlgoRSASHA2256v01,
-	CertSigAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01,
+	CertAlgoRSASHA512v01, CertAlgoRSASHA256v01,
+	CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01,
 	CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01,
 
 	KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521,
-	SigAlgoRSASHA2512, SigAlgoRSASHA2256,
-	SigAlgoRSA, KeyAlgoDSA,
+	KeyAlgoRSASHA512, KeyAlgoRSASHA256,
+	KeyAlgoRSA, KeyAlgoDSA,
 
 	KeyAlgoED25519,
 }
@@ -89,23 +89,33 @@ var supportedMACs = []string{
 
 var supportedCompressions = []string{compressionNone}
 
-// hashFuncs keeps the mapping of supported algorithms to their respective
-// hashes needed for signature verification.
+// hashFuncs keeps the mapping of supported signature algorithms to their
+// respective hashes needed for signing and verification.
 var hashFuncs = map[string]crypto.Hash{
-	SigAlgoRSA:               crypto.SHA1,
-	SigAlgoRSASHA2256:        crypto.SHA256,
-	SigAlgoRSASHA2512:        crypto.SHA512,
-	KeyAlgoDSA:               crypto.SHA1,
-	KeyAlgoECDSA256:          crypto.SHA256,
-	KeyAlgoECDSA384:          crypto.SHA384,
-	KeyAlgoECDSA521:          crypto.SHA512,
-	CertSigAlgoRSAv01:        crypto.SHA1,
-	CertSigAlgoRSASHA2256v01: crypto.SHA256,
-	CertSigAlgoRSASHA2512v01: crypto.SHA512,
-	CertAlgoDSAv01:           crypto.SHA1,
-	CertAlgoECDSA256v01:      crypto.SHA256,
-	CertAlgoECDSA384v01:      crypto.SHA384,
-	CertAlgoECDSA521v01:      crypto.SHA512,
+	KeyAlgoRSA:       crypto.SHA1,
+	KeyAlgoRSASHA256: crypto.SHA256,
+	KeyAlgoRSASHA512: crypto.SHA512,
+	KeyAlgoDSA:       crypto.SHA1,
+	KeyAlgoECDSA256:  crypto.SHA256,
+	KeyAlgoECDSA384:  crypto.SHA384,
+	KeyAlgoECDSA521:  crypto.SHA512,
+	// KeyAlgoED25519 doesn't pre-hash.
+	KeyAlgoSKECDSA256: crypto.SHA256,
+	KeyAlgoSKED25519:  crypto.SHA256,
+}
+
+// algorithmsForKeyFormat returns the supported signature algorithms for a given
+// public key format (PublicKey.Type), in order of preference. See RFC 8332,
+// Section 2. See also the note in sendKexInit on backwards compatibility.
+func algorithmsForKeyFormat(keyFormat string) []string {
+	switch keyFormat {
+	case KeyAlgoRSA:
+		return []string{KeyAlgoRSASHA256, KeyAlgoRSASHA512, KeyAlgoRSA}
+	case CertAlgoRSAv01:
+		return []string{CertAlgoRSASHA256v01, CertAlgoRSASHA512v01, CertAlgoRSAv01}
+	default:
+		return []string{keyFormat}
+	}
 }
 
 // unexpectedMessageError results when the SSH message that we received didn't
@@ -152,6 +162,11 @@ func (a *directionAlgorithms) rekeyBytes() int64 {
 	return 1 << 30
 }
 
+var aeadCiphers = map[string]bool{
+	gcmCipherID:        true,
+	chacha20Poly1305ID: true,
+}
+
 type algorithms struct {
 	kex     string
 	hostKey string
@@ -187,14 +202,18 @@ func findAgreedAlgorithms(isClient bool, clientKexInit, serverKexInit *kexInitMs
 		return
 	}
 
-	ctos.MAC, err = findCommon("client to server MAC", clientKexInit.MACsClientServer, serverKexInit.MACsClientServer)
-	if err != nil {
-		return
+	if !aeadCiphers[ctos.Cipher] {
+		ctos.MAC, err = findCommon("client to server MAC", clientKexInit.MACsClientServer, serverKexInit.MACsClientServer)
+		if err != nil {
+			return
+		}
 	}
 
-	stoc.MAC, err = findCommon("server to client MAC", clientKexInit.MACsServerClient, serverKexInit.MACsServerClient)
-	if err != nil {
-		return
+	if !aeadCiphers[stoc.Cipher] {
+		stoc.MAC, err = findCommon("server to client MAC", clientKexInit.MACsServerClient, serverKexInit.MACsServerClient)
+		if err != nil {
+			return
+		}
 	}
 
 	ctos.Compression, err = findCommon("client to server compression", clientKexInit.CompressionClientServer, serverKexInit.CompressionClientServer)
@@ -278,8 +297,9 @@ func (c *Config) SetDefaults() {
 }
 
 // buildDataSignedForAuth returns the data that is signed in order to prove
-// possession of a private key. See RFC 4252, section 7.
-func buildDataSignedForAuth(sessionID []byte, req userAuthRequestMsg, algo, pubKey []byte) []byte {
+// possession of a private key. See RFC 4252, section 7. algo is the advertised
+// algorithm, and may be a certificate type.
+func buildDataSignedForAuth(sessionID []byte, req userAuthRequestMsg, algo string, pubKey []byte) []byte {
 	data := struct {
 		Session []byte
 		Type    byte
@@ -287,7 +307,7 @@ func buildDataSignedForAuth(sessionID []byte, req userAuthRequestMsg, algo, pubK
 		Service string
 		Method  string
 		Sign    bool
-		Algo    []byte
+		Algo    string
 		PubKey  []byte
 	}{
 		sessionID,
diff --git a/vendor/golang.org/x/crypto/ssh/handshake.go b/vendor/golang.org/x/crypto/ssh/handshake.go
index 05ad49c3..f815cdb4 100644
--- a/vendor/golang.org/x/crypto/ssh/handshake.go
+++ b/vendor/golang.org/x/crypto/ssh/handshake.go
@@ -455,21 +455,36 @@ func (t *handshakeTransport) sendKexInit() error {
 	}
 	io.ReadFull(rand.Reader, msg.Cookie[:])
 
-	if len(t.hostKeys) > 0 {
+	isServer := len(t.hostKeys) > 0
+	if isServer {
 		for _, k := range t.hostKeys {
-			algo := k.PublicKey().Type()
-			switch algo {
-			case KeyAlgoRSA:
-				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, []string{SigAlgoRSASHA2512, SigAlgoRSASHA2256, SigAlgoRSA}...)
-			case CertAlgoRSAv01:
-				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, []string{CertSigAlgoRSASHA2512v01, CertSigAlgoRSASHA2256v01, CertSigAlgoRSAv01}...)
-			default:
-				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algo)
+			// If k is an AlgorithmSigner, presume it supports all signature algorithms
+			// associated with the key format. (Ideally AlgorithmSigner would have a
+			// method to advertise supported algorithms, but it doesn't. This means that
+			// adding support for a new algorithm is a breaking change, as we will
+			// immediately negotiate it even if existing implementations don't support
+			// it. If that ever happens, we'll have to figure something out.)
+			// If k is not an AlgorithmSigner, we can only assume it only supports the
+			// algorithms that matches the key format. (This means that Sign can't pick
+			// a different default.)
+			keyFormat := k.PublicKey().Type()
+			if _, ok := k.(AlgorithmSigner); ok {
+				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, algorithmsForKeyFormat(keyFormat)...)
+			} else {
+				msg.ServerHostKeyAlgos = append(msg.ServerHostKeyAlgos, keyFormat)
 			}
 		}
 	} else {
 		msg.ServerHostKeyAlgos = t.hostKeyAlgorithms
+
+		// As a client we opt in to receiving SSH_MSG_EXT_INFO so we know what
+		// algorithms the server supports for public key authentication. See RFC
+		// 8303, Section 2.1.
+		msg.KexAlgos = make([]string, 0, len(t.config.KeyExchanges)+1)
+		msg.KexAlgos = append(msg.KexAlgos, t.config.KeyExchanges...)
+		msg.KexAlgos = append(msg.KexAlgos, "ext-info-c")
 	}
+
 	packet := Marshal(msg)
 
 	// writePacket destroys the contents, so save a copy.
@@ -589,9 +604,9 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
 
 	var result *kexResult
 	if len(t.hostKeys) > 0 {
-		result, err = t.server(kex, t.algorithms, &magics)
+		result, err = t.server(kex, &magics)
 	} else {
-		result, err = t.client(kex, t.algorithms, &magics)
+		result, err = t.client(kex, &magics)
 	}
 
 	if err != nil {
@@ -618,33 +633,52 @@ func (t *handshakeTransport) enterKeyExchange(otherInitPacket []byte) error {
 	return nil
 }
 
-func (t *handshakeTransport) server(kex kexAlgorithm, algs *algorithms, magics *handshakeMagics) (*kexResult, error) {
-	var hostKey Signer
-	for _, k := range t.hostKeys {
-		kt := k.PublicKey().Type()
-		if kt == algs.hostKey {
-			hostKey = k
-		} else if signer, ok := k.(AlgorithmSigner); ok {
-			// Some signature algorithms don't show up as key types
-			// so we have to manually check for a compatible host key.
-			switch kt {
-			case KeyAlgoRSA:
-				if algs.hostKey == SigAlgoRSASHA2256 || algs.hostKey == SigAlgoRSASHA2512 {
-					hostKey = &rsaSigner{signer, algs.hostKey}
-				}
-			case CertAlgoRSAv01:
-				if algs.hostKey == CertSigAlgoRSASHA2256v01 || algs.hostKey == CertSigAlgoRSASHA2512v01 {
-					hostKey = &rsaSigner{signer, certToPrivAlgo(algs.hostKey)}
-				}
+// algorithmSignerWrapper is an AlgorithmSigner that only supports the default
+// key format algorithm.
+//
+// This is technically a violation of the AlgorithmSigner interface, but it
+// should be unreachable given where we use this. Anyway, at least it returns an
+// error instead of panicing or producing an incorrect signature.
+type algorithmSignerWrapper struct {
+	Signer
+}
+
+func (a algorithmSignerWrapper) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
+	if algorithm != underlyingAlgo(a.PublicKey().Type()) {
+		return nil, errors.New("ssh: internal error: algorithmSignerWrapper invoked with non-default algorithm")
+	}
+	return a.Sign(rand, data)
+}
+
+func pickHostKey(hostKeys []Signer, algo string) AlgorithmSigner {
+	for _, k := range hostKeys {
+		if algo == k.PublicKey().Type() {
+			return algorithmSignerWrapper{k}
+		}
+		k, ok := k.(AlgorithmSigner)
+		if !ok {
+			continue
+		}
+		for _, a := range algorithmsForKeyFormat(k.PublicKey().Type()) {
+			if algo == a {
+				return k
 			}
 		}
 	}
+	return nil
+}
+
+func (t *handshakeTransport) server(kex kexAlgorithm, magics *handshakeMagics) (*kexResult, error) {
+	hostKey := pickHostKey(t.hostKeys, t.algorithms.hostKey)
+	if hostKey == nil {
+		return nil, errors.New("ssh: internal error: negotiated unsupported signature type")
+	}
 
-	r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey)
+	r, err := kex.Server(t.conn, t.config.Rand, magics, hostKey, t.algorithms.hostKey)
 	return r, err
 }
 
-func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *handshakeMagics) (*kexResult, error) {
+func (t *handshakeTransport) client(kex kexAlgorithm, magics *handshakeMagics) (*kexResult, error) {
 	result, err := kex.Client(t.conn, t.config.Rand, magics)
 	if err != nil {
 		return nil, err
@@ -655,7 +689,7 @@ func (t *handshakeTransport) client(kex kexAlgorithm, algs *algorithms, magics *
 		return nil, err
 	}
 
-	if err := verifyHostKeySignature(hostKey, algs.hostKey, result); err != nil {
+	if err := verifyHostKeySignature(hostKey, t.algorithms.hostKey, result); err != nil {
 		return nil, err
 	}
 
diff --git a/vendor/golang.org/x/crypto/ssh/kex.go b/vendor/golang.org/x/crypto/ssh/kex.go
index 766e9293..927a90cd 100644
--- a/vendor/golang.org/x/crypto/ssh/kex.go
+++ b/vendor/golang.org/x/crypto/ssh/kex.go
@@ -20,12 +20,14 @@ import (
 )
 
 const (
-	kexAlgoDH1SHA1          = "diffie-hellman-group1-sha1"
-	kexAlgoDH14SHA1         = "diffie-hellman-group14-sha1"
-	kexAlgoECDH256          = "ecdh-sha2-nistp256"
-	kexAlgoECDH384          = "ecdh-sha2-nistp384"
-	kexAlgoECDH521          = "ecdh-sha2-nistp521"
-	kexAlgoCurve25519SHA256 = "curve25519-sha256@libssh.org"
+	kexAlgoDH1SHA1                = "diffie-hellman-group1-sha1"
+	kexAlgoDH14SHA1               = "diffie-hellman-group14-sha1"
+	kexAlgoDH14SHA256             = "diffie-hellman-group14-sha256"
+	kexAlgoECDH256                = "ecdh-sha2-nistp256"
+	kexAlgoECDH384                = "ecdh-sha2-nistp384"
+	kexAlgoECDH521                = "ecdh-sha2-nistp521"
+	kexAlgoCurve25519SHA256LibSSH = "curve25519-sha256@libssh.org"
+	kexAlgoCurve25519SHA256       = "curve25519-sha256"
 
 	// For the following kex only the client half contains a production
 	// ready implementation. The server half only consists of a minimal
@@ -75,8 +77,9 @@ func (m *handshakeMagics) write(w io.Writer) {
 // kexAlgorithm abstracts different key exchange algorithms.
 type kexAlgorithm interface {
 	// Server runs server-side key agreement, signing the result
-	// with a hostkey.
-	Server(p packetConn, rand io.Reader, magics *handshakeMagics, s Signer) (*kexResult, error)
+	// with a hostkey. algo is the negotiated algorithm, and may
+	// be a certificate type.
+	Server(p packetConn, rand io.Reader, magics *handshakeMagics, s AlgorithmSigner, algo string) (*kexResult, error)
 
 	// Client runs the client-side key agreement. Caller is
 	// responsible for verifying the host key signature.
@@ -86,6 +89,7 @@ type kexAlgorithm interface {
 // dhGroup is a multiplicative group suitable for implementing Diffie-Hellman key agreement.
 type dhGroup struct {
 	g, p, pMinus1 *big.Int
+	hashFunc      crypto.Hash
 }
 
 func (group *dhGroup) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, error) {
@@ -96,8 +100,6 @@ func (group *dhGroup) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int,
 }
 
 func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
-	hashFunc := crypto.SHA1
-
 	var x *big.Int
 	for {
 		var err error
@@ -132,7 +134,7 @@ func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handsha
 		return nil, err
 	}
 
-	h := hashFunc.New()
+	h := group.hashFunc.New()
 	magics.write(h)
 	writeString(h, kexDHReply.HostKey)
 	writeInt(h, X)
@@ -146,12 +148,11 @@ func (group *dhGroup) Client(c packetConn, randSource io.Reader, magics *handsha
 		K:         K,
 		HostKey:   kexDHReply.HostKey,
 		Signature: kexDHReply.Signature,
-		Hash:      crypto.SHA1,
+		Hash:      group.hashFunc,
 	}, nil
 }
 
-func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
-	hashFunc := crypto.SHA1
+func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
 	packet, err := c.readPacket()
 	if err != nil {
 		return
@@ -179,7 +180,7 @@ func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handsha
 
 	hostKeyBytes := priv.PublicKey().Marshal()
 
-	h := hashFunc.New()
+	h := group.hashFunc.New()
 	magics.write(h)
 	writeString(h, hostKeyBytes)
 	writeInt(h, kexDHInit.X)
@@ -193,7 +194,7 @@ func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handsha
 
 	// H is already a hash, but the hostkey signing will apply its
 	// own key-specific hash algorithm.
-	sig, err := signAndMarshal(priv, randSource, H)
+	sig, err := signAndMarshal(priv, randSource, H, algo)
 	if err != nil {
 		return nil, err
 	}
@@ -211,7 +212,7 @@ func (group *dhGroup) Server(c packetConn, randSource io.Reader, magics *handsha
 		K:         K,
 		HostKey:   hostKeyBytes,
 		Signature: sig,
-		Hash:      crypto.SHA1,
+		Hash:      group.hashFunc,
 	}, err
 }
 
@@ -314,7 +315,7 @@ func validateECPublicKey(curve elliptic.Curve, x, y *big.Int) bool {
 	return true
 }
 
-func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
+func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
 	packet, err := c.readPacket()
 	if err != nil {
 		return nil, err
@@ -359,7 +360,7 @@ func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, p
 
 	// H is already a hash, but the hostkey signing will apply its
 	// own key-specific hash algorithm.
-	sig, err := signAndMarshal(priv, rand, H)
+	sig, err := signAndMarshal(priv, rand, H, algo)
 	if err != nil {
 		return nil, err
 	}
@@ -384,39 +385,62 @@ func (kex *ecdh) Server(c packetConn, rand io.Reader, magics *handshakeMagics, p
 	}, nil
 }
 
+// ecHash returns the hash to match the given elliptic curve, see RFC
+// 5656, section 6.2.1
+func ecHash(curve elliptic.Curve) crypto.Hash {
+	bitSize := curve.Params().BitSize
+	switch {
+	case bitSize <= 256:
+		return crypto.SHA256
+	case bitSize <= 384:
+		return crypto.SHA384
+	}
+	return crypto.SHA512
+}
+
 var kexAlgoMap = map[string]kexAlgorithm{}
 
 func init() {
-	// This is the group called diffie-hellman-group1-sha1 in RFC
-	// 4253 and Oakley Group 2 in RFC 2409.
+	// This is the group called diffie-hellman-group1-sha1 in
+	// RFC 4253 and Oakley Group 2 in RFC 2409.
 	p, _ := new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE65381FFFFFFFFFFFFFFFF", 16)
 	kexAlgoMap[kexAlgoDH1SHA1] = &dhGroup{
-		g:       new(big.Int).SetInt64(2),
-		p:       p,
-		pMinus1: new(big.Int).Sub(p, bigOne),
+		g:        new(big.Int).SetInt64(2),
+		p:        p,
+		pMinus1:  new(big.Int).Sub(p, bigOne),
+		hashFunc: crypto.SHA1,
 	}
 
-	// This is the group called diffie-hellman-group14-sha1 in RFC
-	// 4253 and Oakley Group 14 in RFC 3526.
+	// This are the groups called diffie-hellman-group14-sha1 and
+	// diffie-hellman-group14-sha256 in RFC 4253 and RFC 8268,
+	// and Oakley Group 14 in RFC 3526.
 	p, _ = new(big.Int).SetString("FFFFFFFFFFFFFFFFC90FDAA22168C234C4C6628B80DC1CD129024E088A67CC74020BBEA63B139B22514A08798E3404DDEF9519B3CD3A431B302B0A6DF25F14374FE1356D6D51C245E485B576625E7EC6F44C42E9A637ED6B0BFF5CB6F406B7EDEE386BFB5A899FA5AE9F24117C4B1FE649286651ECE45B3DC2007CB8A163BF0598DA48361C55D39A69163FA8FD24CF5F83655D23DCA3AD961C62F356208552BB9ED529077096966D670C354E4ABC9804F1746C08CA18217C32905E462E36CE3BE39E772C180E86039B2783A2EC07A28FB5C55DF06F4C52C9DE2BCBF6955817183995497CEA956AE515D2261898FA051015728E5A8AACAA68FFFFFFFFFFFFFFFF", 16)
-
-	kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
+	group14 := &dhGroup{
 		g:       new(big.Int).SetInt64(2),
 		p:       p,
 		pMinus1: new(big.Int).Sub(p, bigOne),
 	}
 
+	kexAlgoMap[kexAlgoDH14SHA1] = &dhGroup{
+		g: group14.g, p: group14.p, pMinus1: group14.pMinus1,
+		hashFunc: crypto.SHA1,
+	}
+	kexAlgoMap[kexAlgoDH14SHA256] = &dhGroup{
+		g: group14.g, p: group14.p, pMinus1: group14.pMinus1,
+		hashFunc: crypto.SHA256,
+	}
+
 	kexAlgoMap[kexAlgoECDH521] = &ecdh{elliptic.P521()}
 	kexAlgoMap[kexAlgoECDH384] = &ecdh{elliptic.P384()}
 	kexAlgoMap[kexAlgoECDH256] = &ecdh{elliptic.P256()}
 	kexAlgoMap[kexAlgoCurve25519SHA256] = &curve25519sha256{}
+	kexAlgoMap[kexAlgoCurve25519SHA256LibSSH] = &curve25519sha256{}
 	kexAlgoMap[kexAlgoDHGEXSHA1] = &dhGEXSHA{hashFunc: crypto.SHA1}
 	kexAlgoMap[kexAlgoDHGEXSHA256] = &dhGEXSHA{hashFunc: crypto.SHA256}
 }
 
-// curve25519sha256 implements the curve25519-sha256@libssh.org key
-// agreement protocol, as described in
-// https://git.libssh.org/projects/libssh.git/tree/doc/curve25519-sha256@libssh.org.txt
+// curve25519sha256 implements the curve25519-sha256 (formerly known as
+// curve25519-sha256@libssh.org) key exchange method, as described in RFC 8731.
 type curve25519sha256 struct{}
 
 type curve25519KeyPair struct {
@@ -486,7 +510,7 @@ func (kex *curve25519sha256) Client(c packetConn, rand io.Reader, magics *handsh
 	}, nil
 }
 
-func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
+func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
 	packet, err := c.readPacket()
 	if err != nil {
 		return
@@ -527,7 +551,7 @@ func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handsh
 
 	H := h.Sum(nil)
 
-	sig, err := signAndMarshal(priv, rand, H)
+	sig, err := signAndMarshal(priv, rand, H, algo)
 	if err != nil {
 		return nil, err
 	}
@@ -553,7 +577,6 @@ func (kex *curve25519sha256) Server(c packetConn, rand io.Reader, magics *handsh
 // diffie-hellman-group-exchange-sha256 key agreement protocols,
 // as described in RFC 4419
 type dhGEXSHA struct {
-	g, p     *big.Int
 	hashFunc crypto.Hash
 }
 
@@ -563,14 +586,7 @@ const (
 	dhGroupExchangeMaximumBits   = 8192
 )
 
-func (gex *dhGEXSHA) diffieHellman(theirPublic, myPrivate *big.Int) (*big.Int, error) {
-	if theirPublic.Sign() <= 0 || theirPublic.Cmp(gex.p) >= 0 {
-		return nil, fmt.Errorf("ssh: DH parameter out of bounds")
-	}
-	return new(big.Int).Exp(theirPublic, myPrivate, gex.p), nil
-}
-
-func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
+func (gex *dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshakeMagics) (*kexResult, error) {
 	// Send GexRequest
 	kexDHGexRequest := kexDHGexRequestMsg{
 		MinBits:      dhGroupExchangeMinimumBits,
@@ -587,35 +603,29 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
 		return nil, err
 	}
 
-	var kexDHGexGroup kexDHGexGroupMsg
-	if err = Unmarshal(packet, &kexDHGexGroup); err != nil {
+	var msg kexDHGexGroupMsg
+	if err = Unmarshal(packet, &msg); err != nil {
 		return nil, err
 	}
 
 	// reject if p's bit length < dhGroupExchangeMinimumBits or > dhGroupExchangeMaximumBits
-	if kexDHGexGroup.P.BitLen() < dhGroupExchangeMinimumBits || kexDHGexGroup.P.BitLen() > dhGroupExchangeMaximumBits {
-		return nil, fmt.Errorf("ssh: server-generated gex p is out of range (%d bits)", kexDHGexGroup.P.BitLen())
+	if msg.P.BitLen() < dhGroupExchangeMinimumBits || msg.P.BitLen() > dhGroupExchangeMaximumBits {
+		return nil, fmt.Errorf("ssh: server-generated gex p is out of range (%d bits)", msg.P.BitLen())
 	}
 
-	gex.p = kexDHGexGroup.P
-	gex.g = kexDHGexGroup.G
-
-	// Check if g is safe by verifing that g > 1 and g < p - 1
-	one := big.NewInt(1)
-	var pMinusOne = &big.Int{}
-	pMinusOne.Sub(gex.p, one)
-	if gex.g.Cmp(one) != 1 && gex.g.Cmp(pMinusOne) != -1 {
+	// Check if g is safe by verifying that 1 < g < p-1
+	pMinusOne := new(big.Int).Sub(msg.P, bigOne)
+	if msg.G.Cmp(bigOne) <= 0 || msg.G.Cmp(pMinusOne) >= 0 {
 		return nil, fmt.Errorf("ssh: server provided gex g is not safe")
 	}
 
 	// Send GexInit
-	var pHalf = &big.Int{}
-	pHalf.Rsh(gex.p, 1)
+	pHalf := new(big.Int).Rsh(msg.P, 1)
 	x, err := rand.Int(randSource, pHalf)
 	if err != nil {
 		return nil, err
 	}
-	X := new(big.Int).Exp(gex.g, x, gex.p)
+	X := new(big.Int).Exp(msg.G, x, msg.P)
 	kexDHGexInit := kexDHGexInitMsg{
 		X: X,
 	}
@@ -634,13 +644,13 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
 		return nil, err
 	}
 
-	kInt, err := gex.diffieHellman(kexDHGexReply.Y, x)
-	if err != nil {
-		return nil, err
+	if kexDHGexReply.Y.Cmp(bigOne) <= 0 || kexDHGexReply.Y.Cmp(pMinusOne) >= 0 {
+		return nil, errors.New("ssh: DH parameter out of bounds")
 	}
+	kInt := new(big.Int).Exp(kexDHGexReply.Y, x, msg.P)
 
-	// Check if k is safe by verifing that k > 1 and k < p - 1
-	if kInt.Cmp(one) != 1 && kInt.Cmp(pMinusOne) != -1 {
+	// Check if k is safe by verifying that k > 1 and k < p - 1
+	if kInt.Cmp(bigOne) <= 0 || kInt.Cmp(pMinusOne) >= 0 {
 		return nil, fmt.Errorf("ssh: derived k is not safe")
 	}
 
@@ -650,8 +660,8 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
 	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMinimumBits))
 	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangePreferredBits))
 	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMaximumBits))
-	writeInt(h, gex.p)
-	writeInt(h, gex.g)
+	writeInt(h, msg.P)
+	writeInt(h, msg.G)
 	writeInt(h, X)
 	writeInt(h, kexDHGexReply.Y)
 	K := make([]byte, intLength(kInt))
@@ -670,7 +680,7 @@ func (gex dhGEXSHA) Client(c packetConn, randSource io.Reader, magics *handshake
 // Server half implementation of the Diffie Hellman Key Exchange with SHA1 and SHA256.
 //
 // This is a minimal implementation to satisfy the automated tests.
-func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv Signer) (result *kexResult, err error) {
+func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshakeMagics, priv AlgorithmSigner, algo string) (result *kexResult, err error) {
 	// Receive GexRequest
 	packet, err := c.readPacket()
 	if err != nil {
@@ -681,35 +691,17 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
 		return
 	}
 
-	// smoosh the user's preferred size into our own limits
-	if kexDHGexRequest.PreferedBits > dhGroupExchangeMaximumBits {
-		kexDHGexRequest.PreferedBits = dhGroupExchangeMaximumBits
-	}
-	if kexDHGexRequest.PreferedBits < dhGroupExchangeMinimumBits {
-		kexDHGexRequest.PreferedBits = dhGroupExchangeMinimumBits
-	}
-	// fix min/max if they're inconsistent.  technically, we could just pout
-	// and hang up, but there's no harm in giving them the benefit of the
-	// doubt and just picking a bitsize for them.
-	if kexDHGexRequest.MinBits > kexDHGexRequest.PreferedBits {
-		kexDHGexRequest.MinBits = kexDHGexRequest.PreferedBits
-	}
-	if kexDHGexRequest.MaxBits < kexDHGexRequest.PreferedBits {
-		kexDHGexRequest.MaxBits = kexDHGexRequest.PreferedBits
-	}
-
 	// Send GexGroup
 	// This is the group called diffie-hellman-group14-sha1 in RFC
 	// 4253 and Oakley Group 14 in RFC 3526.
 	p, _ := new(big.Int).SetString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
-	gex.p = p
-	gex.g = big.NewInt(2)
+	g := big.NewInt(2)
 
-	kexDHGexGroup := kexDHGexGroupMsg{
-		P: gex.p,
-		G: gex.g,
+	msg := &kexDHGexGroupMsg{
+		P: p,
+		G: g,
 	}
-	if err := c.writePacket(Marshal(&kexDHGexGroup)); err != nil {
+	if err := c.writePacket(Marshal(msg)); err != nil {
 		return nil, err
 	}
 
@@ -723,19 +715,19 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
 		return
 	}
 
-	var pHalf = &big.Int{}
-	pHalf.Rsh(gex.p, 1)
+	pHalf := new(big.Int).Rsh(p, 1)
 
 	y, err := rand.Int(randSource, pHalf)
 	if err != nil {
 		return
 	}
+	Y := new(big.Int).Exp(g, y, p)
 
-	Y := new(big.Int).Exp(gex.g, y, gex.p)
-	kInt, err := gex.diffieHellman(kexDHGexInit.X, y)
-	if err != nil {
-		return nil, err
+	pMinusOne := new(big.Int).Sub(p, bigOne)
+	if kexDHGexInit.X.Cmp(bigOne) <= 0 || kexDHGexInit.X.Cmp(pMinusOne) >= 0 {
+		return nil, errors.New("ssh: DH parameter out of bounds")
 	}
+	kInt := new(big.Int).Exp(kexDHGexInit.X, y, p)
 
 	hostKeyBytes := priv.PublicKey().Marshal()
 
@@ -745,8 +737,8 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
 	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMinimumBits))
 	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangePreferredBits))
 	binary.Write(h, binary.BigEndian, uint32(dhGroupExchangeMaximumBits))
-	writeInt(h, gex.p)
-	writeInt(h, gex.g)
+	writeInt(h, p)
+	writeInt(h, g)
 	writeInt(h, kexDHGexInit.X)
 	writeInt(h, Y)
 
@@ -758,7 +750,7 @@ func (gex dhGEXSHA) Server(c packetConn, randSource io.Reader, magics *handshake
 
 	// H is already a hash, but the hostkey signing will apply its
 	// own key-specific hash algorithm.
-	sig, err := signAndMarshal(priv, randSource, H)
+	sig, err := signAndMarshal(priv, randSource, H, algo)
 	if err != nil {
 		return nil, err
 	}
diff --git a/vendor/golang.org/x/crypto/ssh/keys.go b/vendor/golang.org/x/crypto/ssh/keys.go
index c67d3a31..1c7de1a6 100644
--- a/vendor/golang.org/x/crypto/ssh/keys.go
+++ b/vendor/golang.org/x/crypto/ssh/keys.go
@@ -30,8 +30,9 @@ import (
 	"golang.org/x/crypto/ssh/internal/bcrypt_pbkdf"
 )
 
-// These constants represent the algorithm names for key types supported by this
-// package.
+// Public key algorithms names. These values can appear in PublicKey.Type,
+// ClientConfig.HostKeyAlgorithms, Signature.Format, or as AlgorithmSigner
+// arguments.
 const (
 	KeyAlgoRSA        = "ssh-rsa"
 	KeyAlgoDSA        = "ssh-dss"
@@ -41,16 +42,21 @@ const (
 	KeyAlgoECDSA521   = "ecdsa-sha2-nistp521"
 	KeyAlgoED25519    = "ssh-ed25519"
 	KeyAlgoSKED25519  = "sk-ssh-ed25519@openssh.com"
+
+	// KeyAlgoRSASHA256 and KeyAlgoRSASHA512 are only public key algorithms, not
+	// public key formats, so they can't appear as a PublicKey.Type. The
+	// corresponding PublicKey.Type is KeyAlgoRSA. See RFC 8332, Section 2.
+	KeyAlgoRSASHA256 = "rsa-sha2-256"
+	KeyAlgoRSASHA512 = "rsa-sha2-512"
 )
 
-// These constants represent non-default signature algorithms that are supported
-// as algorithm parameters to AlgorithmSigner.SignWithAlgorithm methods. See
-// [PROTOCOL.agent] section 4.5.1 and
-// https://tools.ietf.org/html/draft-ietf-curdle-rsa-sha2-10
 const (
-	SigAlgoRSA        = "ssh-rsa"
-	SigAlgoRSASHA2256 = "rsa-sha2-256"
-	SigAlgoRSASHA2512 = "rsa-sha2-512"
+	// Deprecated: use KeyAlgoRSA.
+	SigAlgoRSA = KeyAlgoRSA
+	// Deprecated: use KeyAlgoRSASHA256.
+	SigAlgoRSASHA2256 = KeyAlgoRSASHA256
+	// Deprecated: use KeyAlgoRSASHA512.
+	SigAlgoRSASHA2512 = KeyAlgoRSASHA512
 )
 
 // parsePubKey parses a public key of the given algorithm.
@@ -70,7 +76,7 @@ func parsePubKey(in []byte, algo string) (pubKey PublicKey, rest []byte, err err
 	case KeyAlgoSKED25519:
 		return parseSKEd25519(in)
 	case CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoSKECDSA256v01, CertAlgoED25519v01, CertAlgoSKED25519v01:
-		cert, err := parseCert(in, certToPrivAlgo(algo))
+		cert, err := parseCert(in, certKeyAlgoNames[algo])
 		if err != nil {
 			return nil, nil, err
 		}
@@ -289,18 +295,21 @@ func MarshalAuthorizedKey(key PublicKey) []byte {
 	return b.Bytes()
 }
 
-// PublicKey is an abstraction of different types of public keys.
+// PublicKey represents a public key using an unspecified algorithm.
+//
+// Some PublicKeys provided by this package also implement CryptoPublicKey.
 type PublicKey interface {
-	// Type returns the key's type, e.g. "ssh-rsa".
+	// Type returns the key format name, e.g. "ssh-rsa".
 	Type() string
 
-	// Marshal returns the serialized key data in SSH wire format,
-	// with the name prefix. To unmarshal the returned data, use
-	// the ParsePublicKey function.
+	// Marshal returns the serialized key data in SSH wire format, with the name
+	// prefix. To unmarshal the returned data, use the ParsePublicKey function.
 	Marshal() []byte
 
-	// Verify that sig is a signature on the given data using this
-	// key. This function will hash the data appropriately first.
+	// Verify that sig is a signature on the given data using this key. This
+	// method will hash the data appropriately first. sig.Format is allowed to
+	// be any signature algorithm compatible with the key type, the caller
+	// should check if it has more stringent requirements.
 	Verify(data []byte, sig *Signature) error
 }
 
@@ -311,25 +320,32 @@ type CryptoPublicKey interface {
 }
 
 // A Signer can create signatures that verify against a public key.
+//
+// Some Signers provided by this package also implement AlgorithmSigner.
 type Signer interface {
-	// PublicKey returns an associated PublicKey instance.
+	// PublicKey returns the associated PublicKey.
 	PublicKey() PublicKey
 
-	// Sign returns raw signature for the given data. This method
-	// will apply the hash specified for the keytype to the data.
+	// Sign returns a signature for the given data. This method will hash the
+	// data appropriately first. The signature algorithm is expected to match
+	// the key format returned by the PublicKey.Type method (and not to be any
+	// alternative algorithm supported by the key format).
 	Sign(rand io.Reader, data []byte) (*Signature, error)
 }
 
-// A AlgorithmSigner is a Signer that also supports specifying a specific
-// algorithm to use for signing.
+// An AlgorithmSigner is a Signer that also supports specifying an algorithm to
+// use for signing.
+//
+// An AlgorithmSigner can't advertise the algorithms it supports, so it should
+// be prepared to be invoked with every algorithm supported by the public key
+// format.
 type AlgorithmSigner interface {
 	Signer
 
-	// SignWithAlgorithm is like Signer.Sign, but allows specification of a
-	// non-default signing algorithm. See the SigAlgo* constants in this
-	// package for signature algorithms supported by this package. Callers may
-	// pass an empty string for the algorithm in which case the AlgorithmSigner
-	// will use its default algorithm.
+	// SignWithAlgorithm is like Signer.Sign, but allows specifying a desired
+	// signing algorithm. Callers may pass an empty string for the algorithm in
+	// which case the AlgorithmSigner will use a default algorithm. This default
+	// doesn't currently control any behavior in this package.
 	SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error)
 }
 
@@ -381,17 +397,11 @@ func (r *rsaPublicKey) Marshal() []byte {
 }
 
 func (r *rsaPublicKey) Verify(data []byte, sig *Signature) error {
-	var hash crypto.Hash
-	switch sig.Format {
-	case SigAlgoRSA:
-		hash = crypto.SHA1
-	case SigAlgoRSASHA2256:
-		hash = crypto.SHA256
-	case SigAlgoRSASHA2512:
-		hash = crypto.SHA512
-	default:
+	supportedAlgos := algorithmsForKeyFormat(r.Type())
+	if !contains(supportedAlgos, sig.Format) {
 		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, r.Type())
 	}
+	hash := hashFuncs[sig.Format]
 	h := hash.New()
 	h.Write(data)
 	digest := h.Sum(nil)
@@ -466,7 +476,7 @@ func (k *dsaPublicKey) Verify(data []byte, sig *Signature) error {
 	if sig.Format != k.Type() {
 		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
 	}
-	h := crypto.SHA1.New()
+	h := hashFuncs[sig.Format].New()
 	h.Write(data)
 	digest := h.Sum(nil)
 
@@ -499,7 +509,7 @@ func (k *dsaPrivateKey) PublicKey() PublicKey {
 }
 
 func (k *dsaPrivateKey) Sign(rand io.Reader, data []byte) (*Signature, error) {
-	return k.SignWithAlgorithm(rand, data, "")
+	return k.SignWithAlgorithm(rand, data, k.PublicKey().Type())
 }
 
 func (k *dsaPrivateKey) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
@@ -507,7 +517,7 @@ func (k *dsaPrivateKey) SignWithAlgorithm(rand io.Reader, data []byte, algorithm
 		return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
 	}
 
-	h := crypto.SHA1.New()
+	h := hashFuncs[k.PublicKey().Type()].New()
 	h.Write(data)
 	digest := h.Sum(nil)
 	r, s, err := dsa.Sign(rand, k.PrivateKey, digest)
@@ -603,19 +613,6 @@ func supportedEllipticCurve(curve elliptic.Curve) bool {
 	return curve == elliptic.P256() || curve == elliptic.P384() || curve == elliptic.P521()
 }
 
-// ecHash returns the hash to match the given elliptic curve, see RFC
-// 5656, section 6.2.1
-func ecHash(curve elliptic.Curve) crypto.Hash {
-	bitSize := curve.Params().BitSize
-	switch {
-	case bitSize <= 256:
-		return crypto.SHA256
-	case bitSize <= 384:
-		return crypto.SHA384
-	}
-	return crypto.SHA512
-}
-
 // parseECDSA parses an ECDSA key according to RFC 5656, section 3.1.
 func parseECDSA(in []byte) (out PublicKey, rest []byte, err error) {
 	var w struct {
@@ -671,7 +668,7 @@ func (k *ecdsaPublicKey) Verify(data []byte, sig *Signature) error {
 		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
 	}
 
-	h := ecHash(k.Curve).New()
+	h := hashFuncs[sig.Format].New()
 	h.Write(data)
 	digest := h.Sum(nil)
 
@@ -775,7 +772,7 @@ func (k *skECDSAPublicKey) Verify(data []byte, sig *Signature) error {
 		return fmt.Errorf("ssh: signature type %s for key type %s", sig.Format, k.Type())
 	}
 
-	h := ecHash(k.Curve).New()
+	h := hashFuncs[sig.Format].New()
 	h.Write([]byte(k.application))
 	appDigest := h.Sum(nil)
 
@@ -874,7 +871,7 @@ func (k *skEd25519PublicKey) Verify(data []byte, sig *Signature) error {
 		return fmt.Errorf("invalid size %d for Ed25519 public key", l)
 	}
 
-	h := sha256.New()
+	h := hashFuncs[sig.Format].New()
 	h.Write([]byte(k.application))
 	appDigest := h.Sum(nil)
 
@@ -939,15 +936,6 @@ func newDSAPrivateKey(key *dsa.PrivateKey) (Signer, error) {
 	return &dsaPrivateKey{key}, nil
 }
 
-type rsaSigner struct {
-	AlgorithmSigner
-	defaultAlgorithm string
-}
-
-func (s *rsaSigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
-	return s.AlgorithmSigner.SignWithAlgorithm(rand, data, s.defaultAlgorithm)
-}
-
 type wrappedSigner struct {
 	signer crypto.Signer
 	pubKey PublicKey
@@ -970,44 +958,20 @@ func (s *wrappedSigner) PublicKey() PublicKey {
 }
 
 func (s *wrappedSigner) Sign(rand io.Reader, data []byte) (*Signature, error) {
-	return s.SignWithAlgorithm(rand, data, "")
+	return s.SignWithAlgorithm(rand, data, s.pubKey.Type())
 }
 
 func (s *wrappedSigner) SignWithAlgorithm(rand io.Reader, data []byte, algorithm string) (*Signature, error) {
-	var hashFunc crypto.Hash
-
-	if _, ok := s.pubKey.(*rsaPublicKey); ok {
-		// RSA keys support a few hash functions determined by the requested signature algorithm
-		switch algorithm {
-		case "", SigAlgoRSA:
-			algorithm = SigAlgoRSA
-			hashFunc = crypto.SHA1
-		case SigAlgoRSASHA2256:
-			hashFunc = crypto.SHA256
-		case SigAlgoRSASHA2512:
-			hashFunc = crypto.SHA512
-		default:
-			return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
-		}
-	} else {
-		// The only supported algorithm for all other key types is the same as the type of the key
-		if algorithm == "" {
-			algorithm = s.pubKey.Type()
-		} else if algorithm != s.pubKey.Type() {
-			return nil, fmt.Errorf("ssh: unsupported signature algorithm %s", algorithm)
-		}
+	if algorithm == "" {
+		algorithm = s.pubKey.Type()
+	}
 
-		switch key := s.pubKey.(type) {
-		case *dsaPublicKey:
-			hashFunc = crypto.SHA1
-		case *ecdsaPublicKey:
-			hashFunc = ecHash(key.Curve)
-		case ed25519PublicKey:
-		default:
-			return nil, fmt.Errorf("ssh: unsupported key type %T", key)
-		}
+	supportedAlgos := algorithmsForKeyFormat(s.pubKey.Type())
+	if !contains(supportedAlgos, algorithm) {
+		return nil, fmt.Errorf("ssh: unsupported signature algorithm %q for key format %q", algorithm, s.pubKey.Type())
 	}
 
+	hashFunc := hashFuncs[algorithm]
 	var digest []byte
 	if hashFunc != 0 {
 		h := hashFunc.New()
diff --git a/vendor/golang.org/x/crypto/ssh/messages.go b/vendor/golang.org/x/crypto/ssh/messages.go
index ac41a416..19bc67c4 100644
--- a/vendor/golang.org/x/crypto/ssh/messages.go
+++ b/vendor/golang.org/x/crypto/ssh/messages.go
@@ -141,6 +141,14 @@ type serviceAcceptMsg struct {
 	Service string `sshtype:"6"`
 }
 
+// See RFC 8308, section 2.3
+const msgExtInfo = 7
+
+type extInfoMsg struct {
+	NumExtensions uint32 `sshtype:"7"`
+	Payload       []byte `ssh:"rest"`
+}
+
 // See RFC 4252, section 5.
 const msgUserAuthRequest = 50
 
@@ -180,11 +188,11 @@ const msgUserAuthInfoRequest = 60
 const msgUserAuthInfoResponse = 61
 
 type userAuthInfoRequestMsg struct {
-	User               string `sshtype:"60"`
-	Instruction        string
-	DeprecatedLanguage string
-	NumPrompts         uint32
-	Prompts            []byte `ssh:"rest"`
+	Name        string `sshtype:"60"`
+	Instruction string
+	Language    string
+	NumPrompts  uint32
+	Prompts     []byte `ssh:"rest"`
 }
 
 // See RFC 4254, section 5.1.
@@ -782,6 +790,8 @@ func decode(packet []byte) (interface{}, error) {
 		msg = new(serviceRequestMsg)
 	case msgServiceAccept:
 		msg = new(serviceAcceptMsg)
+	case msgExtInfo:
+		msg = new(extInfoMsg)
 	case msgKexInit:
 		msg = new(kexInitMsg)
 	case msgKexDHInit:
@@ -843,6 +853,7 @@ var packetTypeNames = map[byte]string{
 	msgDisconnect:          "disconnectMsg",
 	msgServiceRequest:      "serviceRequestMsg",
 	msgServiceAccept:       "serviceAcceptMsg",
+	msgExtInfo:             "extInfoMsg",
 	msgKexInit:             "kexInitMsg",
 	msgKexDHInit:           "kexDHInitMsg",
 	msgKexDHReply:          "kexDHReplyMsg",
diff --git a/vendor/golang.org/x/crypto/ssh/server.go b/vendor/golang.org/x/crypto/ssh/server.go
index bf5364c3..70045bdf 100644
--- a/vendor/golang.org/x/crypto/ssh/server.go
+++ b/vendor/golang.org/x/crypto/ssh/server.go
@@ -120,7 +120,7 @@ type ServerConfig struct {
 }
 
 // AddHostKey adds a private key as a host key. If an existing host
-// key exists with the same algorithm, it is overwritten. Each server
+// key exists with the same public key format, it is replaced. Each server
 // config must have at least one host key.
 func (s *ServerConfig) AddHostKey(key Signer) {
 	for i, k := range s.hostKeys {
@@ -212,9 +212,10 @@ func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewCha
 }
 
 // signAndMarshal signs the data with the appropriate algorithm,
-// and serializes the result in SSH wire format.
-func signAndMarshal(k Signer, rand io.Reader, data []byte) ([]byte, error) {
-	sig, err := k.Sign(rand, data)
+// and serializes the result in SSH wire format. algo is the negotiate
+// algorithm and may be a certificate type.
+func signAndMarshal(k AlgorithmSigner, rand io.Reader, data []byte, algo string) ([]byte, error) {
+	sig, err := k.SignWithAlgorithm(rand, data, underlyingAlgo(algo))
 	if err != nil {
 		return nil, err
 	}
@@ -284,7 +285,7 @@ func (s *connection) serverHandshake(config *ServerConfig) (*Permissions, error)
 
 func isAcceptableAlgo(algo string) bool {
 	switch algo {
-	case SigAlgoRSA, SigAlgoRSASHA2256, SigAlgoRSASHA2512, KeyAlgoDSA, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, KeyAlgoSKECDSA256, KeyAlgoED25519, KeyAlgoSKED25519,
+	case KeyAlgoRSA, KeyAlgoRSASHA256, KeyAlgoRSASHA512, KeyAlgoDSA, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, KeyAlgoSKECDSA256, KeyAlgoED25519, KeyAlgoSKED25519,
 		CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoSKECDSA256v01, CertAlgoED25519v01, CertAlgoSKED25519v01:
 		return true
 	}
@@ -553,6 +554,7 @@ userAuthLoop:
 				if !ok || len(payload) > 0 {
 					return nil, parseError(msgUserAuthRequest)
 				}
+
 				// Ensure the public key algo and signature algo
 				// are supported.  Compare the private key
 				// algorithm name that corresponds to algo with
@@ -562,7 +564,12 @@ userAuthLoop:
 					authErr = fmt.Errorf("ssh: algorithm %q not accepted", sig.Format)
 					break
 				}
-				signedData := buildDataSignedForAuth(sessionID, userAuthReq, algoBytes, pubKeyData)
+				if underlyingAlgo(algo) != sig.Format {
+					authErr = fmt.Errorf("ssh: signature %q not compatible with selected algorithm %q", sig.Format, algo)
+					break
+				}
+
+				signedData := buildDataSignedForAuth(sessionID, userAuthReq, algo, pubKeyData)
 
 				if err := pubKey.Verify(signedData, sig); err != nil {
 					return nil, err
@@ -694,7 +701,7 @@ type sshClientKeyboardInteractive struct {
 	*connection
 }
 
-func (c *sshClientKeyboardInteractive) Challenge(user, instruction string, questions []string, echos []bool) (answers []string, err error) {
+func (c *sshClientKeyboardInteractive) Challenge(name, instruction string, questions []string, echos []bool) (answers []string, err error) {
 	if len(questions) != len(echos) {
 		return nil, errors.New("ssh: echos and questions must have equal length")
 	}
@@ -706,6 +713,7 @@ func (c *sshClientKeyboardInteractive) Challenge(user, instruction string, quest
 	}
 
 	if err := c.transport.writePacket(Marshal(&userAuthInfoRequestMsg{
+		Name:        name,
 		Instruction: instruction,
 		NumPrompts:  uint32(len(questions)),
 		Prompts:     prompts,
diff --git a/vendor/golang.org/x/crypto/ssh/session.go b/vendor/golang.org/x/crypto/ssh/session.go
index d3321f6b..eca31a22 100644
--- a/vendor/golang.org/x/crypto/ssh/session.go
+++ b/vendor/golang.org/x/crypto/ssh/session.go
@@ -85,6 +85,7 @@ const (
 	IXANY         = 39
 	IXOFF         = 40
 	IMAXBEL       = 41
+	IUTF8         = 42 // RFC 8160
 	ISIG          = 50
 	ICANON        = 51
 	XCASE         = 52
diff --git a/vendor/golang.org/x/crypto/ssh/transport.go b/vendor/golang.org/x/crypto/ssh/transport.go
index 49ddc2e7..acf5a21b 100644
--- a/vendor/golang.org/x/crypto/ssh/transport.go
+++ b/vendor/golang.org/x/crypto/ssh/transport.go
@@ -238,15 +238,19 @@ var (
 // (to setup server->client keys) or clientKeys (for client->server keys).
 func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (packetCipher, error) {
 	cipherMode := cipherModes[algs.Cipher]
-	macMode := macModes[algs.MAC]
 
 	iv := make([]byte, cipherMode.ivSize)
 	key := make([]byte, cipherMode.keySize)
-	macKey := make([]byte, macMode.keySize)
 
 	generateKeyMaterial(iv, d.ivTag, kex)
 	generateKeyMaterial(key, d.keyTag, kex)
-	generateKeyMaterial(macKey, d.macKeyTag, kex)
+
+	var macKey []byte
+	if !aeadCiphers[algs.Cipher] {
+		macMode := macModes[algs.MAC]
+		macKey = make([]byte, macMode.keySize)
+		generateKeyMaterial(macKey, d.macKeyTag, kex)
+	}
 
 	return cipherModes[algs.Cipher].create(key, iv, macKey, algs)
 }