Use mod vendor for vendored directory (backwards compatible)

15 files changed, 308 insertions, 2245 deletions

diff --git a/vendor/golang.org/x/crypto/ssh/LICENSE b/vendor/golang.org/x/crypto/ssh/LICENSE
deleted file mode 100644
index 6a66aea5..00000000
--- a/vendor/golang.org/x/crypto/ssh/LICENSE
+++ /dev/null
@@ -1,27 +0,0 @@
-Copyright (c) 2009 The Go Authors. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/golang.org/x/crypto/ssh/agent/client.go b/vendor/golang.org/x/crypto/ssh/agent/client.go
deleted file mode 100644
index acb5ad80..00000000
--- a/vendor/golang.org/x/crypto/ssh/agent/client.go
+++ /dev/null
@@ -1,683 +0,0 @@
-// Copyright 2012 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 agent implements the ssh-agent protocol, and provides both
-// a client and a server. The client can talk to a standard ssh-agent
-// that uses UNIX sockets, and one could implement an alternative
-// ssh-agent process using the sample server.
-//
-// References:
-//  [PROTOCOL.agent]:    http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.agent?rev=HEAD
-package agent // import "golang.org/x/crypto/ssh/agent"
-
-import (
-	"bytes"
-	"crypto/dsa"
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rsa"
-	"encoding/base64"
-	"encoding/binary"
-	"errors"
-	"fmt"
-	"io"
-	"math/big"
-	"sync"
-
-	"golang.org/x/crypto/ed25519"
-	"golang.org/x/crypto/ssh"
-)
-
-// Agent represents the capabilities of an ssh-agent.
-type Agent interface {
-	// List returns the identities known to the agent.
-	List() ([]*Key, error)
-
-	// Sign has the agent sign the data using a protocol 2 key as defined
-	// in [PROTOCOL.agent] section 2.6.2.
-	Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error)
-
-	// Add adds a private key to the agent.
-	Add(key AddedKey) error
-
-	// Remove removes all identities with the given public key.
-	Remove(key ssh.PublicKey) error
-
-	// RemoveAll removes all identities.
-	RemoveAll() error
-
-	// Lock locks the agent. Sign and Remove will fail, and List will empty an empty list.
-	Lock(passphrase []byte) error
-
-	// Unlock undoes the effect of Lock
-	Unlock(passphrase []byte) error
-
-	// Signers returns signers for all the known keys.
-	Signers() ([]ssh.Signer, error)
-}
-
-// ConstraintExtension describes an optional constraint defined by users.
-type ConstraintExtension struct {
-	// ExtensionName consist of a UTF-8 string suffixed by the
-	// implementation domain following the naming scheme defined
-	// in Section 4.2 of [RFC4251], e.g.  "foo@example.com".
-	ExtensionName string
-	// ExtensionDetails contains the actual content of the extended
-	// constraint.
-	ExtensionDetails []byte
-}
-
-// AddedKey describes an SSH key to be added to an Agent.
-type AddedKey struct {
-	// PrivateKey must be a *rsa.PrivateKey, *dsa.PrivateKey or
-	// *ecdsa.PrivateKey, which will be inserted into the agent.
-	PrivateKey interface{}
-	// Certificate, if not nil, is communicated to the agent and will be
-	// stored with the key.
-	Certificate *ssh.Certificate
-	// Comment is an optional, free-form string.
-	Comment string
-	// LifetimeSecs, if not zero, is the number of seconds that the
-	// agent will store the key for.
-	LifetimeSecs uint32
-	// ConfirmBeforeUse, if true, requests that the agent confirm with the
-	// user before each use of this key.
-	ConfirmBeforeUse bool
-	// ConstraintExtensions are the experimental or private-use constraints
-	// defined by users.
-	ConstraintExtensions []ConstraintExtension
-}
-
-// See [PROTOCOL.agent], section 3.
-const (
-	agentRequestV1Identities   = 1
-	agentRemoveAllV1Identities = 9
-
-	// 3.2 Requests from client to agent for protocol 2 key operations
-	agentAddIdentity         = 17
-	agentRemoveIdentity      = 18
-	agentRemoveAllIdentities = 19
-	agentAddIDConstrained    = 25
-
-	// 3.3 Key-type independent requests from client to agent
-	agentAddSmartcardKey            = 20
-	agentRemoveSmartcardKey         = 21
-	agentLock                       = 22
-	agentUnlock                     = 23
-	agentAddSmartcardKeyConstrained = 26
-
-	// 3.7 Key constraint identifiers
-	agentConstrainLifetime  = 1
-	agentConstrainConfirm   = 2
-	agentConstrainExtension = 3
-)
-
-// maxAgentResponseBytes is the maximum agent reply size that is accepted. This
-// is a sanity check, not a limit in the spec.
-const maxAgentResponseBytes = 16 << 20
-
-// Agent messages:
-// These structures mirror the wire format of the corresponding ssh agent
-// messages found in [PROTOCOL.agent].
-
-// 3.4 Generic replies from agent to client
-const agentFailure = 5
-
-type failureAgentMsg struct{}
-
-const agentSuccess = 6
-
-type successAgentMsg struct{}
-
-// See [PROTOCOL.agent], section 2.5.2.
-const agentRequestIdentities = 11
-
-type requestIdentitiesAgentMsg struct{}
-
-// See [PROTOCOL.agent], section 2.5.2.
-const agentIdentitiesAnswer = 12
-
-type identitiesAnswerAgentMsg struct {
-	NumKeys uint32 `sshtype:"12"`
-	Keys    []byte `ssh:"rest"`
-}
-
-// See [PROTOCOL.agent], section 2.6.2.
-const agentSignRequest = 13
-
-type signRequestAgentMsg struct {
-	KeyBlob []byte `sshtype:"13"`
-	Data    []byte
-	Flags   uint32
-}
-
-// See [PROTOCOL.agent], section 2.6.2.
-
-// 3.6 Replies from agent to client for protocol 2 key operations
-const agentSignResponse = 14
-
-type signResponseAgentMsg struct {
-	SigBlob []byte `sshtype:"14"`
-}
-
-type publicKey struct {
-	Format string
-	Rest   []byte `ssh:"rest"`
-}
-
-// 3.7 Key constraint identifiers
-type constrainLifetimeAgentMsg struct {
-	LifetimeSecs uint32 `sshtype:"1"`
-}
-
-type constrainExtensionAgentMsg struct {
-	ExtensionName    string `sshtype:"3"`
-	ExtensionDetails []byte
-
-	// Rest is a field used for parsing, not part of message
-	Rest []byte `ssh:"rest"`
-}
-
-// Key represents a protocol 2 public key as defined in
-// [PROTOCOL.agent], section 2.5.2.
-type Key struct {
-	Format  string
-	Blob    []byte
-	Comment string
-}
-
-func clientErr(err error) error {
-	return fmt.Errorf("agent: client error: %v", err)
-}
-
-// String returns the storage form of an agent key with the format, base64
-// encoded serialized key, and the comment if it is not empty.
-func (k *Key) String() string {
-	s := string(k.Format) + " " + base64.StdEncoding.EncodeToString(k.Blob)
-
-	if k.Comment != "" {
-		s += " " + k.Comment
-	}
-
-	return s
-}
-
-// Type returns the public key type.
-func (k *Key) Type() string {
-	return k.Format
-}
-
-// Marshal returns key blob to satisfy the ssh.PublicKey interface.
-func (k *Key) Marshal() []byte {
-	return k.Blob
-}
-
-// Verify satisfies the ssh.PublicKey interface.
-func (k *Key) Verify(data []byte, sig *ssh.Signature) error {
-	pubKey, err := ssh.ParsePublicKey(k.Blob)
-	if err != nil {
-		return fmt.Errorf("agent: bad public key: %v", err)
-	}
-	return pubKey.Verify(data, sig)
-}
-
-type wireKey struct {
-	Format string
-	Rest   []byte `ssh:"rest"`
-}
-
-func parseKey(in []byte) (out *Key, rest []byte, err error) {
-	var record struct {
-		Blob    []byte
-		Comment string
-		Rest    []byte `ssh:"rest"`
-	}
-
-	if err := ssh.Unmarshal(in, &record); err != nil {
-		return nil, nil, err
-	}
-
-	var wk wireKey
-	if err := ssh.Unmarshal(record.Blob, &wk); err != nil {
-		return nil, nil, err
-	}
-
-	return &Key{
-		Format:  wk.Format,
-		Blob:    record.Blob,
-		Comment: record.Comment,
-	}, record.Rest, nil
-}
-
-// client is a client for an ssh-agent process.
-type client struct {
-	// conn is typically a *net.UnixConn
-	conn io.ReadWriter
-	// mu is used to prevent concurrent access to the agent
-	mu sync.Mutex
-}
-
-// NewClient returns an Agent that talks to an ssh-agent process over
-// the given connection.
-func NewClient(rw io.ReadWriter) Agent {
-	return &client{conn: rw}
-}
-
-// call sends an RPC to the agent. On success, the reply is
-// unmarshaled into reply and replyType is set to the first byte of
-// the reply, which contains the type of the message.
-func (c *client) call(req []byte) (reply interface{}, err error) {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-
-	msg := make([]byte, 4+len(req))
-	binary.BigEndian.PutUint32(msg, uint32(len(req)))
-	copy(msg[4:], req)
-	if _, err = c.conn.Write(msg); err != nil {
-		return nil, clientErr(err)
-	}
-
-	var respSizeBuf [4]byte
-	if _, err = io.ReadFull(c.conn, respSizeBuf[:]); err != nil {
-		return nil, clientErr(err)
-	}
-	respSize := binary.BigEndian.Uint32(respSizeBuf[:])
-	if respSize > maxAgentResponseBytes {
-		return nil, clientErr(err)
-	}
-
-	buf := make([]byte, respSize)
-	if _, err = io.ReadFull(c.conn, buf); err != nil {
-		return nil, clientErr(err)
-	}
-	reply, err = unmarshal(buf)
-	if err != nil {
-		return nil, clientErr(err)
-	}
-	return reply, err
-}
-
-func (c *client) simpleCall(req []byte) error {
-	resp, err := c.call(req)
-	if err != nil {
-		return err
-	}
-	if _, ok := resp.(*successAgentMsg); ok {
-		return nil
-	}
-	return errors.New("agent: failure")
-}
-
-func (c *client) RemoveAll() error {
-	return c.simpleCall([]byte{agentRemoveAllIdentities})
-}
-
-func (c *client) Remove(key ssh.PublicKey) error {
-	req := ssh.Marshal(&agentRemoveIdentityMsg{
-		KeyBlob: key.Marshal(),
-	})
-	return c.simpleCall(req)
-}
-
-func (c *client) Lock(passphrase []byte) error {
-	req := ssh.Marshal(&agentLockMsg{
-		Passphrase: passphrase,
-	})
-	return c.simpleCall(req)
-}
-
-func (c *client) Unlock(passphrase []byte) error {
-	req := ssh.Marshal(&agentUnlockMsg{
-		Passphrase: passphrase,
-	})
-	return c.simpleCall(req)
-}
-
-// List returns the identities known to the agent.
-func (c *client) List() ([]*Key, error) {
-	// see [PROTOCOL.agent] section 2.5.2.
-	req := []byte{agentRequestIdentities}
-
-	msg, err := c.call(req)
-	if err != nil {
-		return nil, err
-	}
-
-	switch msg := msg.(type) {
-	case *identitiesAnswerAgentMsg:
-		if msg.NumKeys > maxAgentResponseBytes/8 {
-			return nil, errors.New("agent: too many keys in agent reply")
-		}
-		keys := make([]*Key, msg.NumKeys)
-		data := msg.Keys
-		for i := uint32(0); i < msg.NumKeys; i++ {
-			var key *Key
-			var err error
-			if key, data, err = parseKey(data); err != nil {
-				return nil, err
-			}
-			keys[i] = key
-		}
-		return keys, nil
-	case *failureAgentMsg:
-		return nil, errors.New("agent: failed to list keys")
-	}
-	panic("unreachable")
-}
-
-// Sign has the agent sign the data using a protocol 2 key as defined
-// in [PROTOCOL.agent] section 2.6.2.
-func (c *client) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
-	req := ssh.Marshal(signRequestAgentMsg{
-		KeyBlob: key.Marshal(),
-		Data:    data,
-	})
-
-	msg, err := c.call(req)
-	if err != nil {
-		return nil, err
-	}
-
-	switch msg := msg.(type) {
-	case *signResponseAgentMsg:
-		var sig ssh.Signature
-		if err := ssh.Unmarshal(msg.SigBlob, &sig); err != nil {
-			return nil, err
-		}
-
-		return &sig, nil
-	case *failureAgentMsg:
-		return nil, errors.New("agent: failed to sign challenge")
-	}
-	panic("unreachable")
-}
-
-// unmarshal parses an agent message in packet, returning the parsed
-// form and the message type of packet.
-func unmarshal(packet []byte) (interface{}, error) {
-	if len(packet) < 1 {
-		return nil, errors.New("agent: empty packet")
-	}
-	var msg interface{}
-	switch packet[0] {
-	case agentFailure:
-		return new(failureAgentMsg), nil
-	case agentSuccess:
-		return new(successAgentMsg), nil
-	case agentIdentitiesAnswer:
-		msg = new(identitiesAnswerAgentMsg)
-	case agentSignResponse:
-		msg = new(signResponseAgentMsg)
-	case agentV1IdentitiesAnswer:
-		msg = new(agentV1IdentityMsg)
-	default:
-		return nil, fmt.Errorf("agent: unknown type tag %d", packet[0])
-	}
-	if err := ssh.Unmarshal(packet, msg); err != nil {
-		return nil, err
-	}
-	return msg, nil
-}
-
-type rsaKeyMsg struct {
-	Type        string `sshtype:"17|25"`
-	N           *big.Int
-	E           *big.Int
-	D           *big.Int
-	Iqmp        *big.Int // IQMP = Inverse Q Mod P
-	P           *big.Int
-	Q           *big.Int
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-type dsaKeyMsg struct {
-	Type        string `sshtype:"17|25"`
-	P           *big.Int
-	Q           *big.Int
-	G           *big.Int
-	Y           *big.Int
-	X           *big.Int
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-type ecdsaKeyMsg struct {
-	Type        string `sshtype:"17|25"`
-	Curve       string
-	KeyBytes    []byte
-	D           *big.Int
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-type ed25519KeyMsg struct {
-	Type        string `sshtype:"17|25"`
-	Pub         []byte
-	Priv        []byte
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-// Insert adds a private key to the agent.
-func (c *client) insertKey(s interface{}, comment string, constraints []byte) error {
-	var req []byte
-	switch k := s.(type) {
-	case *rsa.PrivateKey:
-		if len(k.Primes) != 2 {
-			return fmt.Errorf("agent: unsupported RSA key with %d primes", len(k.Primes))
-		}
-		k.Precompute()
-		req = ssh.Marshal(rsaKeyMsg{
-			Type:        ssh.KeyAlgoRSA,
-			N:           k.N,
-			E:           big.NewInt(int64(k.E)),
-			D:           k.D,
-			Iqmp:        k.Precomputed.Qinv,
-			P:           k.Primes[0],
-			Q:           k.Primes[1],
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	case *dsa.PrivateKey:
-		req = ssh.Marshal(dsaKeyMsg{
-			Type:        ssh.KeyAlgoDSA,
-			P:           k.P,
-			Q:           k.Q,
-			G:           k.G,
-			Y:           k.Y,
-			X:           k.X,
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	case *ecdsa.PrivateKey:
-		nistID := fmt.Sprintf("nistp%d", k.Params().BitSize)
-		req = ssh.Marshal(ecdsaKeyMsg{
-			Type:        "ecdsa-sha2-" + nistID,
-			Curve:       nistID,
-			KeyBytes:    elliptic.Marshal(k.Curve, k.X, k.Y),
-			D:           k.D,
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	case *ed25519.PrivateKey:
-		req = ssh.Marshal(ed25519KeyMsg{
-			Type:        ssh.KeyAlgoED25519,
-			Pub:         []byte(*k)[32:],
-			Priv:        []byte(*k),
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	default:
-		return fmt.Errorf("agent: unsupported key type %T", s)
-	}
-
-	// if constraints are present then the message type needs to be changed.
-	if len(constraints) != 0 {
-		req[0] = agentAddIDConstrained
-	}
-
-	resp, err := c.call(req)
-	if err != nil {
-		return err
-	}
-	if _, ok := resp.(*successAgentMsg); ok {
-		return nil
-	}
-	return errors.New("agent: failure")
-}
-
-type rsaCertMsg struct {
-	Type        string `sshtype:"17|25"`
-	CertBytes   []byte
-	D           *big.Int
-	Iqmp        *big.Int // IQMP = Inverse Q Mod P
-	P           *big.Int
-	Q           *big.Int
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-type dsaCertMsg struct {
-	Type        string `sshtype:"17|25"`
-	CertBytes   []byte
-	X           *big.Int
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-type ecdsaCertMsg struct {
-	Type        string `sshtype:"17|25"`
-	CertBytes   []byte
-	D           *big.Int
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-type ed25519CertMsg struct {
-	Type        string `sshtype:"17|25"`
-	CertBytes   []byte
-	Pub         []byte
-	Priv        []byte
-	Comments    string
-	Constraints []byte `ssh:"rest"`
-}
-
-// Add adds a private key to the agent. If a certificate is given,
-// that certificate is added instead as public key.
-func (c *client) Add(key AddedKey) error {
-	var constraints []byte
-
-	if secs := key.LifetimeSecs; secs != 0 {
-		constraints = append(constraints, ssh.Marshal(constrainLifetimeAgentMsg{secs})...)
-	}
-
-	if key.ConfirmBeforeUse {
-		constraints = append(constraints, agentConstrainConfirm)
-	}
-
-	cert := key.Certificate
-	if cert == nil {
-		return c.insertKey(key.PrivateKey, key.Comment, constraints)
-	}
-	return c.insertCert(key.PrivateKey, cert, key.Comment, constraints)
-}
-
-func (c *client) insertCert(s interface{}, cert *ssh.Certificate, comment string, constraints []byte) error {
-	var req []byte
-	switch k := s.(type) {
-	case *rsa.PrivateKey:
-		if len(k.Primes) != 2 {
-			return fmt.Errorf("agent: unsupported RSA key with %d primes", len(k.Primes))
-		}
-		k.Precompute()
-		req = ssh.Marshal(rsaCertMsg{
-			Type:        cert.Type(),
-			CertBytes:   cert.Marshal(),
-			D:           k.D,
-			Iqmp:        k.Precomputed.Qinv,
-			P:           k.Primes[0],
-			Q:           k.Primes[1],
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	case *dsa.PrivateKey:
-		req = ssh.Marshal(dsaCertMsg{
-			Type:        cert.Type(),
-			CertBytes:   cert.Marshal(),
-			X:           k.X,
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	case *ecdsa.PrivateKey:
-		req = ssh.Marshal(ecdsaCertMsg{
-			Type:        cert.Type(),
-			CertBytes:   cert.Marshal(),
-			D:           k.D,
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	case *ed25519.PrivateKey:
-		req = ssh.Marshal(ed25519CertMsg{
-			Type:        cert.Type(),
-			CertBytes:   cert.Marshal(),
-			Pub:         []byte(*k)[32:],
-			Priv:        []byte(*k),
-			Comments:    comment,
-			Constraints: constraints,
-		})
-	default:
-		return fmt.Errorf("agent: unsupported key type %T", s)
-	}
-
-	// if constraints are present then the message type needs to be changed.
-	if len(constraints) != 0 {
-		req[0] = agentAddIDConstrained
-	}
-
-	signer, err := ssh.NewSignerFromKey(s)
-	if err != nil {
-		return err
-	}
-	if bytes.Compare(cert.Key.Marshal(), signer.PublicKey().Marshal()) != 0 {
-		return errors.New("agent: signer and cert have different public key")
-	}
-
-	resp, err := c.call(req)
-	if err != nil {
-		return err
-	}
-	if _, ok := resp.(*successAgentMsg); ok {
-		return nil
-	}
-	return errors.New("agent: failure")
-}
-
-// Signers provides a callback for client authentication.
-func (c *client) Signers() ([]ssh.Signer, error) {
-	keys, err := c.List()
-	if err != nil {
-		return nil, err
-	}
-
-	var result []ssh.Signer
-	for _, k := range keys {
-		result = append(result, &agentKeyringSigner{c, k})
-	}
-	return result, nil
-}
-
-type agentKeyringSigner struct {
-	agent *client
-	pub   ssh.PublicKey
-}
-
-func (s *agentKeyringSigner) PublicKey() ssh.PublicKey {
-	return s.pub
-}
-
-func (s *agentKeyringSigner) Sign(rand io.Reader, data []byte) (*ssh.Signature, error) {
-	// The agent has its own entropy source, so the rand argument is ignored.
-	return s.agent.Sign(s.pub, data)
-}
diff --git a/vendor/golang.org/x/crypto/ssh/agent/forward.go b/vendor/golang.org/x/crypto/ssh/agent/forward.go
deleted file mode 100644
index fd24ba90..00000000
--- a/vendor/golang.org/x/crypto/ssh/agent/forward.go
+++ /dev/null
@@ -1,103 +0,0 @@
-// Copyright 2014 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 agent
-
-import (
-	"errors"
-	"io"
-	"net"
-	"sync"
-
-	"golang.org/x/crypto/ssh"
-)
-
-// RequestAgentForwarding sets up agent forwarding for the session.
-// ForwardToAgent or ForwardToRemote should be called to route
-// the authentication requests.
-func RequestAgentForwarding(session *ssh.Session) error {
-	ok, err := session.SendRequest("auth-agent-req@openssh.com", true, nil)
-	if err != nil {
-		return err
-	}
-	if !ok {
-		return errors.New("forwarding request denied")
-	}
-	return nil
-}
-
-// ForwardToAgent routes authentication requests to the given keyring.
-func ForwardToAgent(client *ssh.Client, keyring Agent) error {
-	channels := client.HandleChannelOpen(channelType)
-	if channels == nil {
-		return errors.New("agent: already have handler for " + channelType)
-	}
-
-	go func() {
-		for ch := range channels {
-			channel, reqs, err := ch.Accept()
-			if err != nil {
-				continue
-			}
-			go ssh.DiscardRequests(reqs)
-			go func() {
-				ServeAgent(keyring, channel)
-				channel.Close()
-			}()
-		}
-	}()
-	return nil
-}
-
-const channelType = "auth-agent@openssh.com"
-
-// ForwardToRemote routes authentication requests to the ssh-agent
-// process serving on the given unix socket.
-func ForwardToRemote(client *ssh.Client, addr string) error {
-	channels := client.HandleChannelOpen(channelType)
-	if channels == nil {
-		return errors.New("agent: already have handler for " + channelType)
-	}
-	conn, err := net.Dial("unix", addr)
-	if err != nil {
-		return err
-	}
-	conn.Close()
-
-	go func() {
-		for ch := range channels {
-			channel, reqs, err := ch.Accept()
-			if err != nil {
-				continue
-			}
-			go ssh.DiscardRequests(reqs)
-			go forwardUnixSocket(channel, addr)
-		}
-	}()
-	return nil
-}
-
-func forwardUnixSocket(channel ssh.Channel, addr string) {
-	conn, err := net.Dial("unix", addr)
-	if err != nil {
-		return
-	}
-
-	var wg sync.WaitGroup
-	wg.Add(2)
-	go func() {
-		io.Copy(conn, channel)
-		conn.(*net.UnixConn).CloseWrite()
-		wg.Done()
-	}()
-	go func() {
-		io.Copy(channel, conn)
-		channel.CloseWrite()
-		wg.Done()
-	}()
-
-	wg.Wait()
-	conn.Close()
-	channel.Close()
-}
diff --git a/vendor/golang.org/x/crypto/ssh/agent/keyring.go b/vendor/golang.org/x/crypto/ssh/agent/keyring.go
deleted file mode 100644
index a6ba06ab..00000000
--- a/vendor/golang.org/x/crypto/ssh/agent/keyring.go
+++ /dev/null
@@ -1,215 +0,0 @@
-// Copyright 2014 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 agent
-
-import (
-	"bytes"
-	"crypto/rand"
-	"crypto/subtle"
-	"errors"
-	"fmt"
-	"sync"
-	"time"
-
-	"golang.org/x/crypto/ssh"
-)
-
-type privKey struct {
-	signer  ssh.Signer
-	comment string
-	expire  *time.Time
-}
-
-type keyring struct {
-	mu   sync.Mutex
-	keys []privKey
-
-	locked     bool
-	passphrase []byte
-}
-
-var errLocked = errors.New("agent: locked")
-
-// NewKeyring returns an Agent that holds keys in memory.  It is safe
-// for concurrent use by multiple goroutines.
-func NewKeyring() Agent {
-	return &keyring{}
-}
-
-// RemoveAll removes all identities.
-func (r *keyring) RemoveAll() error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		return errLocked
-	}
-
-	r.keys = nil
-	return nil
-}
-
-// removeLocked does the actual key removal. The caller must already be holding the
-// keyring mutex.
-func (r *keyring) removeLocked(want []byte) error {
-	found := false
-	for i := 0; i < len(r.keys); {
-		if bytes.Equal(r.keys[i].signer.PublicKey().Marshal(), want) {
-			found = true
-			r.keys[i] = r.keys[len(r.keys)-1]
-			r.keys = r.keys[:len(r.keys)-1]
-			continue
-		} else {
-			i++
-		}
-	}
-
-	if !found {
-		return errors.New("agent: key not found")
-	}
-	return nil
-}
-
-// Remove removes all identities with the given public key.
-func (r *keyring) Remove(key ssh.PublicKey) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		return errLocked
-	}
-
-	return r.removeLocked(key.Marshal())
-}
-
-// Lock locks the agent. Sign and Remove will fail, and List will return an empty list.
-func (r *keyring) Lock(passphrase []byte) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		return errLocked
-	}
-
-	r.locked = true
-	r.passphrase = passphrase
-	return nil
-}
-
-// Unlock undoes the effect of Lock
-func (r *keyring) Unlock(passphrase []byte) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if !r.locked {
-		return errors.New("agent: not locked")
-	}
-	if len(passphrase) != len(r.passphrase) || 1 != subtle.ConstantTimeCompare(passphrase, r.passphrase) {
-		return fmt.Errorf("agent: incorrect passphrase")
-	}
-
-	r.locked = false
-	r.passphrase = nil
-	return nil
-}
-
-// expireKeysLocked removes expired keys from the keyring. If a key was added
-// with a lifetimesecs contraint and seconds >= lifetimesecs seconds have
-// ellapsed, it is removed. The caller *must* be holding the keyring mutex.
-func (r *keyring) expireKeysLocked() {
-	for _, k := range r.keys {
-		if k.expire != nil && time.Now().After(*k.expire) {
-			r.removeLocked(k.signer.PublicKey().Marshal())
-		}
-	}
-}
-
-// List returns the identities known to the agent.
-func (r *keyring) List() ([]*Key, error) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		// section 2.7: locked agents return empty.
-		return nil, nil
-	}
-
-	r.expireKeysLocked()
-	var ids []*Key
-	for _, k := range r.keys {
-		pub := k.signer.PublicKey()
-		ids = append(ids, &Key{
-			Format:  pub.Type(),
-			Blob:    pub.Marshal(),
-			Comment: k.comment})
-	}
-	return ids, nil
-}
-
-// Insert adds a private key to the keyring. If a certificate
-// is given, that certificate is added as public key. Note that
-// any constraints given are ignored.
-func (r *keyring) Add(key AddedKey) error {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		return errLocked
-	}
-	signer, err := ssh.NewSignerFromKey(key.PrivateKey)
-
-	if err != nil {
-		return err
-	}
-
-	if cert := key.Certificate; cert != nil {
-		signer, err = ssh.NewCertSigner(cert, signer)
-		if err != nil {
-			return err
-		}
-	}
-
-	p := privKey{
-		signer:  signer,
-		comment: key.Comment,
-	}
-
-	if key.LifetimeSecs > 0 {
-		t := time.Now().Add(time.Duration(key.LifetimeSecs) * time.Second)
-		p.expire = &t
-	}
-
-	r.keys = append(r.keys, p)
-
-	return nil
-}
-
-// Sign returns a signature for the data.
-func (r *keyring) Sign(key ssh.PublicKey, data []byte) (*ssh.Signature, error) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		return nil, errLocked
-	}
-
-	r.expireKeysLocked()
-	wanted := key.Marshal()
-	for _, k := range r.keys {
-		if bytes.Equal(k.signer.PublicKey().Marshal(), wanted) {
-			return k.signer.Sign(rand.Reader, data)
-		}
-	}
-	return nil, errors.New("not found")
-}
-
-// Signers returns signers for all the known keys.
-func (r *keyring) Signers() ([]ssh.Signer, error) {
-	r.mu.Lock()
-	defer r.mu.Unlock()
-	if r.locked {
-		return nil, errLocked
-	}
-
-	r.expireKeysLocked()
-	s := make([]ssh.Signer, 0, len(r.keys))
-	for _, k := range r.keys {
-		s = append(s, k.signer)
-	}
-	return s, nil
-}
diff --git a/vendor/golang.org/x/crypto/ssh/agent/server.go b/vendor/golang.org/x/crypto/ssh/agent/server.go
deleted file mode 100644
index 2e4692cb..00000000
--- a/vendor/golang.org/x/crypto/ssh/agent/server.go
+++ /dev/null
@@ -1,523 +0,0 @@
-// Copyright 2012 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 agent
-
-import (
-	"crypto/dsa"
-	"crypto/ecdsa"
-	"crypto/elliptic"
-	"crypto/rsa"
-	"encoding/binary"
-	"errors"
-	"fmt"
-	"io"
-	"log"
-	"math/big"
-
-	"golang.org/x/crypto/ed25519"
-	"golang.org/x/crypto/ssh"
-)
-
-// Server wraps an Agent and uses it to implement the agent side of
-// the SSH-agent, wire protocol.
-type server struct {
-	agent Agent
-}
-
-func (s *server) processRequestBytes(reqData []byte) []byte {
-	rep, err := s.processRequest(reqData)
-	if err != nil {
-		if err != errLocked {
-			// TODO(hanwen): provide better logging interface?
-			log.Printf("agent %d: %v", reqData[0], err)
-		}
-		return []byte{agentFailure}
-	}
-
-	if err == nil && rep == nil {
-		return []byte{agentSuccess}
-	}
-
-	return ssh.Marshal(rep)
-}
-
-func marshalKey(k *Key) []byte {
-	var record struct {
-		Blob    []byte
-		Comment string
-	}
-	record.Blob = k.Marshal()
-	record.Comment = k.Comment
-
-	return ssh.Marshal(&record)
-}
-
-// See [PROTOCOL.agent], section 2.5.1.
-const agentV1IdentitiesAnswer = 2
-
-type agentV1IdentityMsg struct {
-	Numkeys uint32 `sshtype:"2"`
-}
-
-type agentRemoveIdentityMsg struct {
-	KeyBlob []byte `sshtype:"18"`
-}
-
-type agentLockMsg struct {
-	Passphrase []byte `sshtype:"22"`
-}
-
-type agentUnlockMsg struct {
-	Passphrase []byte `sshtype:"23"`
-}
-
-func (s *server) processRequest(data []byte) (interface{}, error) {
-	switch data[0] {
-	case agentRequestV1Identities:
-		return &agentV1IdentityMsg{0}, nil
-
-	case agentRemoveAllV1Identities:
-		return nil, nil
-
-	case agentRemoveIdentity:
-		var req agentRemoveIdentityMsg
-		if err := ssh.Unmarshal(data, &req); err != nil {
-			return nil, err
-		}
-
-		var wk wireKey
-		if err := ssh.Unmarshal(req.KeyBlob, &wk); err != nil {
-			return nil, err
-		}
-
-		return nil, s.agent.Remove(&Key{Format: wk.Format, Blob: req.KeyBlob})
-
-	case agentRemoveAllIdentities:
-		return nil, s.agent.RemoveAll()
-
-	case agentLock:
-		var req agentLockMsg
-		if err := ssh.Unmarshal(data, &req); err != nil {
-			return nil, err
-		}
-
-		return nil, s.agent.Lock(req.Passphrase)
-
-	case agentUnlock:
-		var req agentUnlockMsg
-		if err := ssh.Unmarshal(data, &req); err != nil {
-			return nil, err
-		}
-		return nil, s.agent.Unlock(req.Passphrase)
-
-	case agentSignRequest:
-		var req signRequestAgentMsg
-		if err := ssh.Unmarshal(data, &req); err != nil {
-			return nil, err
-		}
-
-		var wk wireKey
-		if err := ssh.Unmarshal(req.KeyBlob, &wk); err != nil {
-			return nil, err
-		}
-
-		k := &Key{
-			Format: wk.Format,
-			Blob:   req.KeyBlob,
-		}
-
-		sig, err := s.agent.Sign(k, req.Data) //  TODO(hanwen): flags.
-		if err != nil {
-			return nil, err
-		}
-		return &signResponseAgentMsg{SigBlob: ssh.Marshal(sig)}, nil
-
-	case agentRequestIdentities:
-		keys, err := s.agent.List()
-		if err != nil {
-			return nil, err
-		}
-
-		rep := identitiesAnswerAgentMsg{
-			NumKeys: uint32(len(keys)),
-		}
-		for _, k := range keys {
-			rep.Keys = append(rep.Keys, marshalKey(k)...)
-		}
-		return rep, nil
-
-	case agentAddIDConstrained, agentAddIdentity:
-		return nil, s.insertIdentity(data)
-	}
-
-	return nil, fmt.Errorf("unknown opcode %d", data[0])
-}
-
-func parseConstraints(constraints []byte) (lifetimeSecs uint32, confirmBeforeUse bool, extensions []ConstraintExtension, err error) {
-	for len(constraints) != 0 {
-		switch constraints[0] {
-		case agentConstrainLifetime:
-			lifetimeSecs = binary.BigEndian.Uint32(constraints[1:5])
-			constraints = constraints[5:]
-		case agentConstrainConfirm:
-			confirmBeforeUse = true
-			constraints = constraints[1:]
-		case agentConstrainExtension:
-			var msg constrainExtensionAgentMsg
-			if err = ssh.Unmarshal(constraints, &msg); err != nil {
-				return 0, false, nil, err
-			}
-			extensions = append(extensions, ConstraintExtension{
-				ExtensionName:    msg.ExtensionName,
-				ExtensionDetails: msg.ExtensionDetails,
-			})
-			constraints = msg.Rest
-		default:
-			return 0, false, nil, fmt.Errorf("unknown constraint type: %d", constraints[0])
-		}
-	}
-	return
-}
-
-func setConstraints(key *AddedKey, constraintBytes []byte) error {
-	lifetimeSecs, confirmBeforeUse, constraintExtensions, err := parseConstraints(constraintBytes)
-	if err != nil {
-		return err
-	}
-
-	key.LifetimeSecs = lifetimeSecs
-	key.ConfirmBeforeUse = confirmBeforeUse
-	key.ConstraintExtensions = constraintExtensions
-	return nil
-}
-
-func parseRSAKey(req []byte) (*AddedKey, error) {
-	var k rsaKeyMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-	if k.E.BitLen() > 30 {
-		return nil, errors.New("agent: RSA public exponent too large")
-	}
-	priv := &rsa.PrivateKey{
-		PublicKey: rsa.PublicKey{
-			E: int(k.E.Int64()),
-			N: k.N,
-		},
-		D:      k.D,
-		Primes: []*big.Int{k.P, k.Q},
-	}
-	priv.Precompute()
-
-	addedKey := &AddedKey{PrivateKey: priv, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func parseEd25519Key(req []byte) (*AddedKey, error) {
-	var k ed25519KeyMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-	priv := ed25519.PrivateKey(k.Priv)
-
-	addedKey := &AddedKey{PrivateKey: &priv, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func parseDSAKey(req []byte) (*AddedKey, error) {
-	var k dsaKeyMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-	priv := &dsa.PrivateKey{
-		PublicKey: dsa.PublicKey{
-			Parameters: dsa.Parameters{
-				P: k.P,
-				Q: k.Q,
-				G: k.G,
-			},
-			Y: k.Y,
-		},
-		X: k.X,
-	}
-
-	addedKey := &AddedKey{PrivateKey: priv, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func unmarshalECDSA(curveName string, keyBytes []byte, privScalar *big.Int) (priv *ecdsa.PrivateKey, err error) {
-	priv = &ecdsa.PrivateKey{
-		D: privScalar,
-	}
-
-	switch curveName {
-	case "nistp256":
-		priv.Curve = elliptic.P256()
-	case "nistp384":
-		priv.Curve = elliptic.P384()
-	case "nistp521":
-		priv.Curve = elliptic.P521()
-	default:
-		return nil, fmt.Errorf("agent: unknown curve %q", curveName)
-	}
-
-	priv.X, priv.Y = elliptic.Unmarshal(priv.Curve, keyBytes)
-	if priv.X == nil || priv.Y == nil {
-		return nil, errors.New("agent: point not on curve")
-	}
-
-	return priv, nil
-}
-
-func parseEd25519Cert(req []byte) (*AddedKey, error) {
-	var k ed25519CertMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
-	if err != nil {
-		return nil, err
-	}
-	priv := ed25519.PrivateKey(k.Priv)
-	cert, ok := pubKey.(*ssh.Certificate)
-	if !ok {
-		return nil, errors.New("agent: bad ED25519 certificate")
-	}
-
-	addedKey := &AddedKey{PrivateKey: &priv, Certificate: cert, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func parseECDSAKey(req []byte) (*AddedKey, error) {
-	var k ecdsaKeyMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-
-	priv, err := unmarshalECDSA(k.Curve, k.KeyBytes, k.D)
-	if err != nil {
-		return nil, err
-	}
-
-	addedKey := &AddedKey{PrivateKey: priv, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func parseRSACert(req []byte) (*AddedKey, error) {
-	var k rsaCertMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-
-	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
-	if err != nil {
-		return nil, err
-	}
-
-	cert, ok := pubKey.(*ssh.Certificate)
-	if !ok {
-		return nil, errors.New("agent: bad RSA certificate")
-	}
-
-	// An RSA publickey as marshaled by rsaPublicKey.Marshal() in keys.go
-	var rsaPub struct {
-		Name string
-		E    *big.Int
-		N    *big.Int
-	}
-	if err := ssh.Unmarshal(cert.Key.Marshal(), &rsaPub); err != nil {
-		return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
-	}
-
-	if rsaPub.E.BitLen() > 30 {
-		return nil, errors.New("agent: RSA public exponent too large")
-	}
-
-	priv := rsa.PrivateKey{
-		PublicKey: rsa.PublicKey{
-			E: int(rsaPub.E.Int64()),
-			N: rsaPub.N,
-		},
-		D:      k.D,
-		Primes: []*big.Int{k.Q, k.P},
-	}
-	priv.Precompute()
-
-	addedKey := &AddedKey{PrivateKey: &priv, Certificate: cert, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func parseDSACert(req []byte) (*AddedKey, error) {
-	var k dsaCertMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
-	if err != nil {
-		return nil, err
-	}
-	cert, ok := pubKey.(*ssh.Certificate)
-	if !ok {
-		return nil, errors.New("agent: bad DSA certificate")
-	}
-
-	// A DSA publickey as marshaled by dsaPublicKey.Marshal() in keys.go
-	var w struct {
-		Name       string
-		P, Q, G, Y *big.Int
-	}
-	if err := ssh.Unmarshal(cert.Key.Marshal(), &w); err != nil {
-		return nil, fmt.Errorf("agent: Unmarshal failed to parse public key: %v", err)
-	}
-
-	priv := &dsa.PrivateKey{
-		PublicKey: dsa.PublicKey{
-			Parameters: dsa.Parameters{
-				P: w.P,
-				Q: w.Q,
-				G: w.G,
-			},
-			Y: w.Y,
-		},
-		X: k.X,
-	}
-
-	addedKey := &AddedKey{PrivateKey: priv, Certificate: cert, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func parseECDSACert(req []byte) (*AddedKey, error) {
-	var k ecdsaCertMsg
-	if err := ssh.Unmarshal(req, &k); err != nil {
-		return nil, err
-	}
-
-	pubKey, err := ssh.ParsePublicKey(k.CertBytes)
-	if err != nil {
-		return nil, err
-	}
-	cert, ok := pubKey.(*ssh.Certificate)
-	if !ok {
-		return nil, errors.New("agent: bad ECDSA certificate")
-	}
-
-	// An ECDSA publickey as marshaled by ecdsaPublicKey.Marshal() in keys.go
-	var ecdsaPub struct {
-		Name string
-		ID   string
-		Key  []byte
-	}
-	if err := ssh.Unmarshal(cert.Key.Marshal(), &ecdsaPub); err != nil {
-		return nil, err
-	}
-
-	priv, err := unmarshalECDSA(ecdsaPub.ID, ecdsaPub.Key, k.D)
-	if err != nil {
-		return nil, err
-	}
-
-	addedKey := &AddedKey{PrivateKey: priv, Certificate: cert, Comment: k.Comments}
-	if err := setConstraints(addedKey, k.Constraints); err != nil {
-		return nil, err
-	}
-	return addedKey, nil
-}
-
-func (s *server) insertIdentity(req []byte) error {
-	var record struct {
-		Type string `sshtype:"17|25"`
-		Rest []byte `ssh:"rest"`
-	}
-
-	if err := ssh.Unmarshal(req, &record); err != nil {
-		return err
-	}
-
-	var addedKey *AddedKey
-	var err error
-
-	switch record.Type {
-	case ssh.KeyAlgoRSA:
-		addedKey, err = parseRSAKey(req)
-	case ssh.KeyAlgoDSA:
-		addedKey, err = parseDSAKey(req)
-	case ssh.KeyAlgoECDSA256, ssh.KeyAlgoECDSA384, ssh.KeyAlgoECDSA521:
-		addedKey, err = parseECDSAKey(req)
-	case ssh.KeyAlgoED25519:
-		addedKey, err = parseEd25519Key(req)
-	case ssh.CertAlgoRSAv01:
-		addedKey, err = parseRSACert(req)
-	case ssh.CertAlgoDSAv01:
-		addedKey, err = parseDSACert(req)
-	case ssh.CertAlgoECDSA256v01, ssh.CertAlgoECDSA384v01, ssh.CertAlgoECDSA521v01:
-		addedKey, err = parseECDSACert(req)
-	case ssh.CertAlgoED25519v01:
-		addedKey, err = parseEd25519Cert(req)
-	default:
-		return fmt.Errorf("agent: not implemented: %q", record.Type)
-	}
-
-	if err != nil {
-		return err
-	}
-	return s.agent.Add(*addedKey)
-}
-
-// ServeAgent serves the agent protocol on the given connection. It
-// returns when an I/O error occurs.
-func ServeAgent(agent Agent, c io.ReadWriter) error {
-	s := &server{agent}
-
-	var length [4]byte
-	for {
-		if _, err := io.ReadFull(c, length[:]); err != nil {
-			return err
-		}
-		l := binary.BigEndian.Uint32(length[:])
-		if l > maxAgentResponseBytes {
-			// We also cap requests.
-			return fmt.Errorf("agent: request too large: %d", l)
-		}
-
-		req := make([]byte, l)
-		if _, err := io.ReadFull(c, req); err != nil {
-			return err
-		}
-
-		repData := s.processRequestBytes(req)
-		if len(repData) > maxAgentResponseBytes {
-			return fmt.Errorf("agent: reply too large: %d bytes", len(repData))
-		}
-
-		binary.BigEndian.PutUint32(length[:], uint32(len(repData)))
-		if _, err := c.Write(length[:]); err != nil {
-			return err
-		}
-		if _, err := c.Write(repData); err != nil {
-			return err
-		}
-	}
-}
diff --git a/vendor/golang.org/x/crypto/ssh/certs.go b/vendor/golang.org/x/crypto/ssh/certs.go
index 5c9fadce..42106f3f 100644
--- a/vendor/golang.org/x/crypto/ssh/certs.go
+++ b/vendor/golang.org/x/crypto/ssh/certs.go
@@ -44,7 +44,9 @@ type Signature struct {
 const CertTimeInfinity = 1<<64 - 1
 
 // An Certificate represents an OpenSSH certificate as defined in
-// [PROTOCOL.certkeys]?rev=1.8.
+// [PROTOCOL.certkeys]?rev=1.8. The Certificate type implements the
+// PublicKey interface, so it can be unmarshaled using
+// ParsePublicKey.
 type Certificate struct {
 	Nonce           []byte
 	Key             PublicKey
@@ -340,7 +342,7 @@ func (c *CertChecker) Authenticate(conn ConnMetadata, pubKey PublicKey) (*Permis
 // the signature of the certificate.
 func (c *CertChecker) CheckCert(principal string, cert *Certificate) error {
 	if c.IsRevoked != nil && c.IsRevoked(cert) {
-		return fmt.Errorf("ssh: certicate serial %d revoked", cert.Serial)
+		return fmt.Errorf("ssh: certificate serial %d revoked", cert.Serial)
 	}
 
 	for opt := range cert.CriticalOptions {
diff --git a/vendor/golang.org/x/crypto/ssh/cipher.go b/vendor/golang.org/x/crypto/ssh/cipher.go
index e67c5e0a..30a49fdf 100644
--- a/vendor/golang.org/x/crypto/ssh/cipher.go
+++ b/vendor/golang.org/x/crypto/ssh/cipher.go
@@ -16,6 +16,9 @@ import (
 	"hash"
 	"io"
 	"io/ioutil"
+
+	"golang.org/x/crypto/internal/chacha20"
+	"golang.org/x/crypto/poly1305"
 )
 
 const (
@@ -53,78 +56,78 @@ func newRC4(key, iv []byte) (cipher.Stream, error) {
 	return rc4.NewCipher(key)
 }
 
-type streamCipherMode struct {
-	keySize    int
-	ivSize     int
-	skip       int
-	createFunc func(key, iv []byte) (cipher.Stream, error)
+type cipherMode struct {
+	keySize int
+	ivSize  int
+	create  func(key, iv []byte, macKey []byte, algs directionAlgorithms) (packetCipher, error)
 }
 
-func (c *streamCipherMode) createStream(key, iv []byte) (cipher.Stream, error) {
-	if len(key) < c.keySize {
-		panic("ssh: key length too small for cipher")
-	}
-	if len(iv) < c.ivSize {
-		panic("ssh: iv too small for cipher")
-	}
-
-	stream, err := c.createFunc(key[:c.keySize], iv[:c.ivSize])
-	if err != nil {
-		return nil, err
-	}
+func streamCipherMode(skip int, createFunc func(key, iv []byte) (cipher.Stream, error)) func(key, iv []byte, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+	return func(key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+		stream, err := createFunc(key, iv)
+		if err != nil {
+			return nil, err
+		}
 
-	var streamDump []byte
-	if c.skip > 0 {
-		streamDump = make([]byte, 512)
-	}
+		var streamDump []byte
+		if skip > 0 {
+			streamDump = make([]byte, 512)
+		}
 
-	for remainingToDump := c.skip; remainingToDump > 0; {
-		dumpThisTime := remainingToDump
-		if dumpThisTime > len(streamDump) {
-			dumpThisTime = len(streamDump)
+		for remainingToDump := skip; remainingToDump > 0; {
+			dumpThisTime := remainingToDump
+			if dumpThisTime > len(streamDump) {
+				dumpThisTime = len(streamDump)
+			}
+			stream.XORKeyStream(streamDump[:dumpThisTime], streamDump[:dumpThisTime])
+			remainingToDump -= dumpThisTime
 		}
-		stream.XORKeyStream(streamDump[:dumpThisTime], streamDump[:dumpThisTime])
-		remainingToDump -= dumpThisTime
-	}
 
-	return stream, nil
+		mac := macModes[algs.MAC].new(macKey)
+		return &streamPacketCipher{
+			mac:       mac,
+			etm:       macModes[algs.MAC].etm,
+			macResult: make([]byte, mac.Size()),
+			cipher:    stream,
+		}, nil
+	}
 }
 
 // cipherModes documents properties of supported ciphers. Ciphers not included
 // are not supported and will not be negotiated, even if explicitly requested in
 // ClientConfig.Crypto.Ciphers.
-var cipherModes = map[string]*streamCipherMode{
+var cipherModes = map[string]*cipherMode{
 	// Ciphers from RFC4344, which introduced many CTR-based ciphers. Algorithms
 	// are defined in the order specified in the RFC.
-	"aes128-ctr": {16, aes.BlockSize, 0, newAESCTR},
-	"aes192-ctr": {24, aes.BlockSize, 0, newAESCTR},
-	"aes256-ctr": {32, aes.BlockSize, 0, newAESCTR},
+	"aes128-ctr": {16, aes.BlockSize, streamCipherMode(0, newAESCTR)},
+	"aes192-ctr": {24, aes.BlockSize, streamCipherMode(0, newAESCTR)},
+	"aes256-ctr": {32, aes.BlockSize, streamCipherMode(0, newAESCTR)},
 
 	// Ciphers from RFC4345, which introduces security-improved arcfour ciphers.
 	// They are defined in the order specified in the RFC.
-	"arcfour128": {16, 0, 1536, newRC4},
-	"arcfour256": {32, 0, 1536, newRC4},
+	"arcfour128": {16, 0, streamCipherMode(1536, newRC4)},
+	"arcfour256": {32, 0, streamCipherMode(1536, newRC4)},
 
 	// Cipher defined in RFC 4253, which describes SSH Transport Layer Protocol.
 	// Note that this cipher is not safe, as stated in RFC 4253: "Arcfour (and
 	// RC4) has problems with weak keys, and should be used with caution."
 	// RFC4345 introduces improved versions of Arcfour.
-	"arcfour": {16, 0, 0, newRC4},
+	"arcfour": {16, 0, streamCipherMode(0, newRC4)},
 
-	// AES-GCM is not a stream cipher, so it is constructed with a
-	// special case. If we add any more non-stream ciphers, we
-	// should invest a cleaner way to do this.
-	gcmCipherID: {16, 12, 0, nil},
+	// AEAD ciphers
+	gcmCipherID:        {16, 12, newGCMCipher},
+	chacha20Poly1305ID: {64, 0, newChaCha20Cipher},
 
 	// CBC mode is insecure and so is not included in the default config.
 	// (See http://www.isg.rhul.ac.uk/~kp/SandPfinal.pdf). If absolutely
 	// needed, it's possible to specify a custom Config to enable it.
 	// You should expect that an active attacker can recover plaintext if
 	// you do.
-	aes128cbcID: {16, aes.BlockSize, 0, nil},
+	aes128cbcID: {16, aes.BlockSize, newAESCBCCipher},
 
-	// 3des-cbc is insecure and is disabled by default.
-	tripledescbcID: {24, des.BlockSize, 0, nil},
+	// 3des-cbc is insecure and is not included in the default
+	// config.
+	tripledescbcID: {24, des.BlockSize, newTripleDESCBCCipher},
 }
 
 // prefixLen is the length of the packet prefix that contains the packet length
@@ -304,7 +307,7 @@ type gcmCipher struct {
 	buf    []byte
 }
 
-func newGCMCipher(iv, key []byte) (packetCipher, error) {
+func newGCMCipher(key, iv, unusedMacKey []byte, unusedAlgs directionAlgorithms) (packetCipher, error) {
 	c, err := aes.NewCipher(key)
 	if err != nil {
 		return nil, err
@@ -422,7 +425,7 @@ type cbcCipher struct {
 	oracleCamouflage uint32
 }
 
-func newCBCCipher(c cipher.Block, iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+func newCBCCipher(c cipher.Block, key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
 	cbc := &cbcCipher{
 		mac:        macModes[algs.MAC].new(macKey),
 		decrypter:  cipher.NewCBCDecrypter(c, iv),
@@ -436,13 +439,13 @@ func newCBCCipher(c cipher.Block, iv, key, macKey []byte, algs directionAlgorith
 	return cbc, nil
 }
 
-func newAESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+func newAESCBCCipher(key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
 	c, err := aes.NewCipher(key)
 	if err != nil {
 		return nil, err
 	}
 
-	cbc, err := newCBCCipher(c, iv, key, macKey, algs)
+	cbc, err := newCBCCipher(c, key, iv, macKey, algs)
 	if err != nil {
 		return nil, err
 	}
@@ -450,13 +453,13 @@ func newAESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCi
 	return cbc, nil
 }
 
-func newTripleDESCBCCipher(iv, key, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
+func newTripleDESCBCCipher(key, iv, macKey []byte, algs directionAlgorithms) (packetCipher, error) {
 	c, err := des.NewTripleDESCipher(key)
 	if err != nil {
 		return nil, err
 	}
 
-	cbc, err := newCBCCipher(c, iv, key, macKey, algs)
+	cbc, err := newCBCCipher(c, key, iv, macKey, algs)
 	if err != nil {
 		return nil, err
 	}
@@ -627,3 +630,142 @@ func (c *cbcCipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, pack
 
 	return nil
 }
+
+const chacha20Poly1305ID = "chacha20-poly1305@openssh.com"
+
+// chacha20Poly1305Cipher implements the chacha20-poly1305@openssh.com
+// AEAD, which is described here:
+//
+//   https://tools.ietf.org/html/draft-josefsson-ssh-chacha20-poly1305-openssh-00
+//
+// the methods here also implement padding, which RFC4253 Section 6
+// also requires of stream ciphers.
+type chacha20Poly1305Cipher struct {
+	lengthKey  [32]byte
+	contentKey [32]byte
+	buf        []byte
+}
+
+func newChaCha20Cipher(key, unusedIV, unusedMACKey []byte, unusedAlgs directionAlgorithms) (packetCipher, error) {
+	if len(key) != 64 {
+		panic(len(key))
+	}
+
+	c := &chacha20Poly1305Cipher{
+		buf: make([]byte, 256),
+	}
+
+	copy(c.contentKey[:], key[:32])
+	copy(c.lengthKey[:], key[32:])
+	return c, nil
+}
+
+// The Poly1305 key is obtained by encrypting 32 0-bytes.
+var chacha20PolyKeyInput [32]byte
+
+func (c *chacha20Poly1305Cipher) readPacket(seqNum uint32, r io.Reader) ([]byte, error) {
+	var counter [16]byte
+	binary.BigEndian.PutUint64(counter[8:], uint64(seqNum))
+
+	var polyKey [32]byte
+	chacha20.XORKeyStream(polyKey[:], chacha20PolyKeyInput[:], &counter, &c.contentKey)
+
+	encryptedLength := c.buf[:4]
+	if _, err := io.ReadFull(r, encryptedLength); err != nil {
+		return nil, err
+	}
+
+	var lenBytes [4]byte
+	chacha20.XORKeyStream(lenBytes[:], encryptedLength, &counter, &c.lengthKey)
+
+	length := binary.BigEndian.Uint32(lenBytes[:])
+	if length > maxPacket {
+		return nil, errors.New("ssh: invalid packet length, packet too large")
+	}
+
+	contentEnd := 4 + length
+	packetEnd := contentEnd + poly1305.TagSize
+	if uint32(cap(c.buf)) < packetEnd {
+		c.buf = make([]byte, packetEnd)
+		copy(c.buf[:], encryptedLength)
+	} else {
+		c.buf = c.buf[:packetEnd]
+	}
+
+	if _, err := io.ReadFull(r, c.buf[4:packetEnd]); err != nil {
+		return nil, err
+	}
+
+	var mac [poly1305.TagSize]byte
+	copy(mac[:], c.buf[contentEnd:packetEnd])
+	if !poly1305.Verify(&mac, c.buf[:contentEnd], &polyKey) {
+		return nil, errors.New("ssh: MAC failure")
+	}
+
+	counter[0] = 1
+
+	plain := c.buf[4:contentEnd]
+	chacha20.XORKeyStream(plain, plain, &counter, &c.contentKey)
+
+	padding := plain[0]
+	if padding < 4 {
+		// padding is a byte, so it automatically satisfies
+		// the maximum size, which is 255.
+		return nil, fmt.Errorf("ssh: illegal padding %d", padding)
+	}
+
+	if int(padding)+1 >= len(plain) {
+		return nil, fmt.Errorf("ssh: padding %d too large", padding)
+	}
+
+	plain = plain[1 : len(plain)-int(padding)]
+
+	return plain, nil
+}
+
+func (c *chacha20Poly1305Cipher) writePacket(seqNum uint32, w io.Writer, rand io.Reader, payload []byte) error {
+	var counter [16]byte
+	binary.BigEndian.PutUint64(counter[8:], uint64(seqNum))
+
+	var polyKey [32]byte
+	chacha20.XORKeyStream(polyKey[:], chacha20PolyKeyInput[:], &counter, &c.contentKey)
+
+	// There is no blocksize, so fall back to multiple of 8 byte
+	// padding, as described in RFC 4253, Sec 6.
+	const packetSizeMultiple = 8
+
+	padding := packetSizeMultiple - (1+len(payload))%packetSizeMultiple
+	if padding < 4 {
+		padding += packetSizeMultiple
+	}
+
+	// size (4 bytes), padding (1), payload, padding, tag.
+	totalLength := 4 + 1 + len(payload) + padding + poly1305.TagSize
+	if cap(c.buf) < totalLength {
+		c.buf = make([]byte, totalLength)
+	} else {
+		c.buf = c.buf[:totalLength]
+	}
+
+	binary.BigEndian.PutUint32(c.buf, uint32(1+len(payload)+padding))
+	chacha20.XORKeyStream(c.buf, c.buf[:4], &counter, &c.lengthKey)
+	c.buf[4] = byte(padding)
+	copy(c.buf[5:], payload)
+	packetEnd := 5 + len(payload) + padding
+	if _, err := io.ReadFull(rand, c.buf[5+len(payload):packetEnd]); err != nil {
+		return err
+	}
+
+	counter[0] = 1
+	chacha20.XORKeyStream(c.buf[4:], c.buf[4:packetEnd], &counter, &c.contentKey)
+
+	var mac [poly1305.TagSize]byte
+	poly1305.Sum(&mac, c.buf[:packetEnd], &polyKey)
+
+	copy(c.buf[packetEnd:], mac[:])
+
+	if _, err := w.Write(c.buf); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/vendor/golang.org/x/crypto/ssh/client_auth.go b/vendor/golang.org/x/crypto/ssh/client_auth.go
index a1252cb9..5f44b774 100644
--- a/vendor/golang.org/x/crypto/ssh/client_auth.go
+++ b/vendor/golang.org/x/crypto/ssh/client_auth.go
@@ -11,6 +11,14 @@ import (
 	"io"
 )
 
+type authResult int
+
+const (
+	authFailure authResult = iota
+	authPartialSuccess
+	authSuccess
+)
+
 // clientAuthenticate authenticates with the remote server. See RFC 4252.
 func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	// initiate user auth session
@@ -37,11 +45,12 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 		if err != nil {
 			return err
 		}
-		if ok {
+		if ok == authSuccess {
 			// success
 			return nil
+		} else if ok == authFailure {
+			tried[auth.method()] = true
 		}
-		tried[auth.method()] = true
 		if methods == nil {
 			methods = lastMethods
 		}
@@ -82,7 +91,7 @@ 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) (bool, []string, error)
+	auth(session []byte, user string, p packetConn, rand io.Reader) (authResult, []string, error)
 
 	// method returns the RFC 4252 method name.
 	method() string
@@ -91,13 +100,13 @@ 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) (bool, []string, error) {
+func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	if err := c.writePacket(Marshal(&userAuthRequestMsg{
 		User:    user,
 		Service: serviceSSH,
 		Method:  "none",
 	})); err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	return handleAuthResponse(c)
@@ -111,7 +120,7 @@ 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) (bool, []string, error) {
+func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	type passwordAuthMsg struct {
 		User     string `sshtype:"50"`
 		Service  string
@@ -125,7 +134,7 @@ func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand
 	// The program may only find out that the user doesn't have a password
 	// when prompting.
 	if err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	if err := c.writePacket(Marshal(&passwordAuthMsg{
@@ -135,7 +144,7 @@ func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand
 		Reply:    false,
 		Password: pw,
 	})); err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	return handleAuthResponse(c)
@@ -178,7 +187,7 @@ func (cb publicKeyCallback) method() string {
 	return "publickey"
 }
 
-func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (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
@@ -186,13 +195,13 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 
 	signers, err := cb()
 	if err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 	var methods []string
 	for _, signer := range signers {
 		ok, err := validateKey(signer.PublicKey(), user, c)
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 		if !ok {
 			continue
@@ -206,7 +215,7 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 			Method:  cb.method(),
 		}, []byte(pub.Type()), pubKey))
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// manually wrap the serialized signature in a string
@@ -224,24 +233,24 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 		}
 		p := Marshal(&msg)
 		if err := c.writePacket(p); err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
-		var success bool
+		var success authResult
 		success, methods, err = handleAuthResponse(c)
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// If authentication succeeds or the list of available methods does not
 		// contain the "publickey" method, do not attempt to authenticate with any
 		// other keys.  According to RFC 4252 Section 7, the latter can occur when
 		// additional authentication methods are required.
-		if success || !containsMethod(methods, cb.method()) {
+		if success == authSuccess || !containsMethod(methods, cb.method()) {
 			return success, methods, err
 		}
 	}
 
-	return false, methods, nil
+	return authFailure, methods, nil
 }
 
 func containsMethod(methods []string, method string) bool {
@@ -318,28 +327,31 @@ func PublicKeysCallback(getSigners func() (signers []Signer, err error)) AuthMet
 // handleAuthResponse returns whether the preceding authentication request succeeded
 // along with a list of remaining authentication methods to try next and
 // an error if an unexpected response was received.
-func handleAuthResponse(c packetConn) (bool, []string, error) {
+func handleAuthResponse(c packetConn) (authResult, []string, error) {
 	for {
 		packet, err := c.readPacket()
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		switch packet[0] {
 		case msgUserAuthBanner:
 			if err := handleBannerResponse(c, packet); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
 		case msgUserAuthFailure:
 			var msg userAuthFailureMsg
 			if err := Unmarshal(packet, &msg); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
-			return false, msg.Methods, nil
+			if msg.PartialSuccess {
+				return authPartialSuccess, msg.Methods, nil
+			}
+			return authFailure, msg.Methods, nil
 		case msgUserAuthSuccess:
-			return true, nil, nil
+			return authSuccess, nil, nil
 		default:
-			return false, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
+			return authFailure, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
 		}
 	}
 }
@@ -381,7 +393,7 @@ func (cb KeyboardInteractiveChallenge) method() string {
 	return "keyboard-interactive"
 }
 
-func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	type initiateMsg struct {
 		User       string `sshtype:"50"`
 		Service    string
@@ -395,20 +407,20 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		Service: serviceSSH,
 		Method:  "keyboard-interactive",
 	})); err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	for {
 		packet, err := c.readPacket()
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// like handleAuthResponse, but with less options.
 		switch packet[0] {
 		case msgUserAuthBanner:
 			if err := handleBannerResponse(c, packet); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
 			continue
 		case msgUserAuthInfoRequest:
@@ -416,18 +428,21 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		case msgUserAuthFailure:
 			var msg userAuthFailureMsg
 			if err := Unmarshal(packet, &msg); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
+			}
+			if msg.PartialSuccess {
+				return authPartialSuccess, msg.Methods, nil
 			}
-			return false, msg.Methods, nil
+			return authFailure, msg.Methods, nil
 		case msgUserAuthSuccess:
-			return true, nil, nil
+			return authSuccess, nil, nil
 		default:
-			return false, nil, unexpectedMessageError(msgUserAuthInfoRequest, packet[0])
+			return authFailure, nil, unexpectedMessageError(msgUserAuthInfoRequest, packet[0])
 		}
 
 		var msg userAuthInfoRequestMsg
 		if err := Unmarshal(packet, &msg); err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// Manually unpack the prompt/echo pairs.
@@ -437,7 +452,7 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		for i := 0; i < int(msg.NumPrompts); i++ {
 			prompt, r, ok := parseString(rest)
 			if !ok || len(r) == 0 {
-				return false, nil, errors.New("ssh: prompt format error")
+				return authFailure, nil, errors.New("ssh: prompt format error")
 			}
 			prompts = append(prompts, string(prompt))
 			echos = append(echos, r[0] != 0)
@@ -445,16 +460,16 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		}
 
 		if len(rest) != 0 {
-			return false, nil, errors.New("ssh: extra data following keyboard-interactive pairs")
+			return authFailure, nil, errors.New("ssh: extra data following keyboard-interactive pairs")
 		}
 
 		answers, err := cb(msg.User, msg.Instruction, prompts, echos)
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		if len(answers) != len(prompts) {
-			return false, nil, errors.New("ssh: not enough answers from keyboard-interactive callback")
+			return authFailure, nil, errors.New("ssh: not enough answers from keyboard-interactive callback")
 		}
 		responseLength := 1 + 4
 		for _, a := range answers {
@@ -470,7 +485,7 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		}
 
 		if err := c.writePacket(serialized); err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 	}
 }
@@ -480,10 +495,10 @@ type retryableAuthMethod struct {
 	maxTries   int
 }
 
-func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader) (ok bool, methods []string, err error) {
+func (r *retryableAuthMethod) auth(session []byte, user string, c packetConn, rand io.Reader) (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)
-		if ok || err != nil { // either success or error terminate
+		if ok != authFailure || err != nil { // either success, partial success or error terminate
 			return ok, methods, err
 		}
 	}
diff --git a/vendor/golang.org/x/crypto/ssh/common.go b/vendor/golang.org/x/crypto/ssh/common.go
index 135b4edd..04f3620b 100644
--- a/vendor/golang.org/x/crypto/ssh/common.go
+++ b/vendor/golang.org/x/crypto/ssh/common.go
@@ -24,11 +24,21 @@ const (
 	serviceSSH      = "ssh-connection"
 )
 
-// supportedCiphers specifies the supported ciphers in preference order.
+// supportedCiphers lists ciphers we support but might not recommend.
 var supportedCiphers = []string{
 	"aes128-ctr", "aes192-ctr", "aes256-ctr",
 	"aes128-gcm@openssh.com",
-	"arcfour256", "arcfour128",
+	chacha20Poly1305ID,
+	"arcfour256", "arcfour128", "arcfour",
+	aes128cbcID,
+	tripledescbcID,
+}
+
+// preferredCiphers specifies the default preference for ciphers.
+var preferredCiphers = []string{
+	"aes128-gcm@openssh.com",
+	chacha20Poly1305ID,
+	"aes128-ctr", "aes192-ctr", "aes256-ctr",
 }
 
 // supportedKexAlgos specifies the supported key-exchange algorithms in
@@ -211,7 +221,7 @@ func (c *Config) SetDefaults() {
 		c.Rand = rand.Reader
 	}
 	if c.Ciphers == nil {
-		c.Ciphers = supportedCiphers
+		c.Ciphers = preferredCiphers
 	}
 	var ciphers []string
 	for _, c := range c.Ciphers {
diff --git a/vendor/golang.org/x/crypto/ssh/keys.go b/vendor/golang.org/x/crypto/ssh/keys.go
index dadf41ab..73697ded 100644
--- a/vendor/golang.org/x/crypto/ssh/keys.go
+++ b/vendor/golang.org/x/crypto/ssh/keys.go
@@ -276,7 +276,8 @@ type PublicKey interface {
 	Type() string
 
 	// Marshal returns the serialized key data in SSH wire format,
-	// with the name prefix.
+	// 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
diff --git a/vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go b/vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go
deleted file mode 100644
index 448fc07f..00000000
--- a/vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go
+++ /dev/null
@@ -1,546 +0,0 @@
-// Copyright 2017 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 knownhosts implements a parser for the OpenSSH
-// known_hosts host key database.
-package knownhosts
-
-import (
-	"bufio"
-	"bytes"
-	"crypto/hmac"
-	"crypto/rand"
-	"crypto/sha1"
-	"encoding/base64"
-	"errors"
-	"fmt"
-	"io"
-	"net"
-	"os"
-	"strings"
-
-	"golang.org/x/crypto/ssh"
-)
-
-// See the sshd manpage
-// (http://man.openbsd.org/sshd#SSH_KNOWN_HOSTS_FILE_FORMAT) for
-// background.
-
-type addr struct{ host, port string }
-
-func (a *addr) String() string {
-	h := a.host
-	if strings.Contains(h, ":") {
-		h = "[" + h + "]"
-	}
-	return h + ":" + a.port
-}
-
-type matcher interface {
-	match([]addr) bool
-}
-
-type hostPattern struct {
-	negate bool
-	addr   addr
-}
-
-func (p *hostPattern) String() string {
-	n := ""
-	if p.negate {
-		n = "!"
-	}
-
-	return n + p.addr.String()
-}
-
-type hostPatterns []hostPattern
-
-func (ps hostPatterns) match(addrs []addr) bool {
-	matched := false
-	for _, p := range ps {
-		for _, a := range addrs {
-			m := p.match(a)
-			if !m {
-				continue
-			}
-			if p.negate {
-				return false
-			}
-			matched = true
-		}
-	}
-	return matched
-}
-
-// See
-// https://android.googlesource.com/platform/external/openssh/+/ab28f5495c85297e7a597c1ba62e996416da7c7e/addrmatch.c
-// The matching of * has no regard for separators, unlike filesystem globs
-func wildcardMatch(pat []byte, str []byte) bool {
-	for {
-		if len(pat) == 0 {
-			return len(str) == 0
-		}
-		if len(str) == 0 {
-			return false
-		}
-
-		if pat[0] == '*' {
-			if len(pat) == 1 {
-				return true
-			}
-
-			for j := range str {
-				if wildcardMatch(pat[1:], str[j:]) {
-					return true
-				}
-			}
-			return false
-		}
-
-		if pat[0] == '?' || pat[0] == str[0] {
-			pat = pat[1:]
-			str = str[1:]
-		} else {
-			return false
-		}
-	}
-}
-
-func (p *hostPattern) match(a addr) bool {
-	return wildcardMatch([]byte(p.addr.host), []byte(a.host)) && p.addr.port == a.port
-}
-
-type keyDBLine struct {
-	cert     bool
-	matcher  matcher
-	knownKey KnownKey
-}
-
-func serialize(k ssh.PublicKey) string {
-	return k.Type() + " " + base64.StdEncoding.EncodeToString(k.Marshal())
-}
-
-func (l *keyDBLine) match(addrs []addr) bool {
-	return l.matcher.match(addrs)
-}
-
-type hostKeyDB struct {
-	// Serialized version of revoked keys
-	revoked map[string]*KnownKey
-	lines   []keyDBLine
-}
-
-func newHostKeyDB() *hostKeyDB {
-	db := &hostKeyDB{
-		revoked: make(map[string]*KnownKey),
-	}
-
-	return db
-}
-
-func keyEq(a, b ssh.PublicKey) bool {
-	return bytes.Equal(a.Marshal(), b.Marshal())
-}
-
-// IsAuthorityForHost can be used as a callback in ssh.CertChecker
-func (db *hostKeyDB) IsHostAuthority(remote ssh.PublicKey, address string) bool {
-	h, p, err := net.SplitHostPort(address)
-	if err != nil {
-		return false
-	}
-	a := addr{host: h, port: p}
-
-	for _, l := range db.lines {
-		if l.cert && keyEq(l.knownKey.Key, remote) && l.match([]addr{a}) {
-			return true
-		}
-	}
-	return false
-}
-
-// IsRevoked can be used as a callback in ssh.CertChecker
-func (db *hostKeyDB) IsRevoked(key *ssh.Certificate) bool {
-	_, ok := db.revoked[string(key.Marshal())]
-	return ok
-}
-
-const markerCert = "@cert-authority"
-const markerRevoked = "@revoked"
-
-func nextWord(line []byte) (string, []byte) {
-	i := bytes.IndexAny(line, "\t ")
-	if i == -1 {
-		return string(line), nil
-	}
-
-	return string(line[:i]), bytes.TrimSpace(line[i:])
-}
-
-func parseLine(line []byte) (marker, host string, key ssh.PublicKey, err error) {
-	if w, next := nextWord(line); w == markerCert || w == markerRevoked {
-		marker = w
-		line = next
-	}
-
-	host, line = nextWord(line)
-	if len(line) == 0 {
-		return "", "", nil, errors.New("knownhosts: missing host pattern")
-	}
-
-	// ignore the keytype as it's in the key blob anyway.
-	_, line = nextWord(line)
-	if len(line) == 0 {
-		return "", "", nil, errors.New("knownhosts: missing key type pattern")
-	}
-
-	keyBlob, _ := nextWord(line)
-
-	keyBytes, err := base64.StdEncoding.DecodeString(keyBlob)
-	if err != nil {
-		return "", "", nil, err
-	}
-	key, err = ssh.ParsePublicKey(keyBytes)
-	if err != nil {
-		return "", "", nil, err
-	}
-
-	return marker, host, key, nil
-}
-
-func (db *hostKeyDB) parseLine(line []byte, filename string, linenum int) error {
-	marker, pattern, key, err := parseLine(line)
-	if err != nil {
-		return err
-	}
-
-	if marker == markerRevoked {
-		db.revoked[string(key.Marshal())] = &KnownKey{
-			Key:      key,
-			Filename: filename,
-			Line:     linenum,
-		}
-
-		return nil
-	}
-
-	entry := keyDBLine{
-		cert: marker == markerCert,
-		knownKey: KnownKey{
-			Filename: filename,
-			Line:     linenum,
-			Key:      key,
-		},
-	}
-
-	if pattern[0] == '|' {
-		entry.matcher, err = newHashedHost(pattern)
-	} else {
-		entry.matcher, err = newHostnameMatcher(pattern)
-	}
-
-	if err != nil {
-		return err
-	}
-
-	db.lines = append(db.lines, entry)
-	return nil
-}
-
-func newHostnameMatcher(pattern string) (matcher, error) {
-	var hps hostPatterns
-	for _, p := range strings.Split(pattern, ",") {
-		if len(p) == 0 {
-			continue
-		}
-
-		var a addr
-		var negate bool
-		if p[0] == '!' {
-			negate = true
-			p = p[1:]
-		}
-
-		if len(p) == 0 {
-			return nil, errors.New("knownhosts: negation without following hostname")
-		}
-
-		var err error
-		if p[0] == '[' {
-			a.host, a.port, err = net.SplitHostPort(p)
-			if err != nil {
-				return nil, err
-			}
-		} else {
-			a.host, a.port, err = net.SplitHostPort(p)
-			if err != nil {
-				a.host = p
-				a.port = "22"
-			}
-		}
-		hps = append(hps, hostPattern{
-			negate: negate,
-			addr:   a,
-		})
-	}
-	return hps, nil
-}
-
-// KnownKey represents a key declared in a known_hosts file.
-type KnownKey struct {
-	Key      ssh.PublicKey
-	Filename string
-	Line     int
-}
-
-func (k *KnownKey) String() string {
-	return fmt.Sprintf("%s:%d: %s", k.Filename, k.Line, serialize(k.Key))
-}
-
-// KeyError is returned if we did not find the key in the host key
-// database, or there was a mismatch.  Typically, in batch
-// applications, this should be interpreted as failure. Interactive
-// applications can offer an interactive prompt to the user.
-type KeyError struct {
-	// Want holds the accepted host keys. For each key algorithm,
-	// there can be one hostkey.  If Want is empty, the host is
-	// unknown. If Want is non-empty, there was a mismatch, which
-	// can signify a MITM attack.
-	Want []KnownKey
-}
-
-func (u *KeyError) Error() string {
-	if len(u.Want) == 0 {
-		return "knownhosts: key is unknown"
-	}
-	return "knownhosts: key mismatch"
-}
-
-// RevokedError is returned if we found a key that was revoked.
-type RevokedError struct {
-	Revoked KnownKey
-}
-
-func (r *RevokedError) Error() string {
-	return "knownhosts: key is revoked"
-}
-
-// check checks a key against the host database. This should not be
-// used for verifying certificates.
-func (db *hostKeyDB) check(address string, remote net.Addr, remoteKey ssh.PublicKey) error {
-	if revoked := db.revoked[string(remoteKey.Marshal())]; revoked != nil {
-		return &RevokedError{Revoked: *revoked}
-	}
-
-	host, port, err := net.SplitHostPort(remote.String())
-	if err != nil {
-		return fmt.Errorf("knownhosts: SplitHostPort(%s): %v", remote, err)
-	}
-
-	addrs := []addr{
-		{host, port},
-	}
-
-	if address != "" {
-		host, port, err := net.SplitHostPort(address)
-		if err != nil {
-			return fmt.Errorf("knownhosts: SplitHostPort(%s): %v", address, err)
-		}
-
-		addrs = append(addrs, addr{host, port})
-	}
-
-	return db.checkAddrs(addrs, remoteKey)
-}
-
-// checkAddrs checks if we can find the given public key for any of
-// the given addresses.  If we only find an entry for the IP address,
-// or only the hostname, then this still succeeds.
-func (db *hostKeyDB) checkAddrs(addrs []addr, remoteKey ssh.PublicKey) error {
-	// TODO(hanwen): are these the right semantics? What if there
-	// is just a key for the IP address, but not for the
-	// hostname?
-
-	// Algorithm => key.
-	knownKeys := map[string]KnownKey{}
-	for _, l := range db.lines {
-		if l.match(addrs) {
-			typ := l.knownKey.Key.Type()
-			if _, ok := knownKeys[typ]; !ok {
-				knownKeys[typ] = l.knownKey
-			}
-		}
-	}
-
-	keyErr := &KeyError{}
-	for _, v := range knownKeys {
-		keyErr.Want = append(keyErr.Want, v)
-	}
-
-	// Unknown remote host.
-	if len(knownKeys) == 0 {
-		return keyErr
-	}
-
-	// If the remote host starts using a different, unknown key type, we
-	// also interpret that as a mismatch.
-	if known, ok := knownKeys[remoteKey.Type()]; !ok || !keyEq(known.Key, remoteKey) {
-		return keyErr
-	}
-
-	return nil
-}
-
-// The Read function parses file contents.
-func (db *hostKeyDB) Read(r io.Reader, filename string) error {
-	scanner := bufio.NewScanner(r)
-
-	lineNum := 0
-	for scanner.Scan() {
-		lineNum++
-		line := scanner.Bytes()
-		line = bytes.TrimSpace(line)
-		if len(line) == 0 || line[0] == '#' {
-			continue
-		}
-
-		if err := db.parseLine(line, filename, lineNum); err != nil {
-			return fmt.Errorf("knownhosts: %s:%d: %v", filename, lineNum, err)
-		}
-	}
-	return scanner.Err()
-}
-
-// New creates a host key callback from the given OpenSSH host key
-// files. The returned callback is for use in
-// ssh.ClientConfig.HostKeyCallback. Hashed hostnames are not supported.
-func New(files ...string) (ssh.HostKeyCallback, error) {
-	db := newHostKeyDB()
-	for _, fn := range files {
-		f, err := os.Open(fn)
-		if err != nil {
-			return nil, err
-		}
-		defer f.Close()
-		if err := db.Read(f, fn); err != nil {
-			return nil, err
-		}
-	}
-
-	var certChecker ssh.CertChecker
-	certChecker.IsHostAuthority = db.IsHostAuthority
-	certChecker.IsRevoked = db.IsRevoked
-	certChecker.HostKeyFallback = db.check
-
-	return certChecker.CheckHostKey, nil
-}
-
-// Normalize normalizes an address into the form used in known_hosts
-func Normalize(address string) string {
-	host, port, err := net.SplitHostPort(address)
-	if err != nil {
-		host = address
-		port = "22"
-	}
-	entry := host
-	if port != "22" {
-		entry = "[" + entry + "]:" + port
-	} else if strings.Contains(host, ":") && !strings.HasPrefix(host, "[") {
-		entry = "[" + entry + "]"
-	}
-	return entry
-}
-
-// Line returns a line to add append to the known_hosts files.
-func Line(addresses []string, key ssh.PublicKey) string {
-	var trimmed []string
-	for _, a := range addresses {
-		trimmed = append(trimmed, Normalize(a))
-	}
-
-	return strings.Join(trimmed, ",") + " " + serialize(key)
-}
-
-// HashHostname hashes the given hostname. The hostname is not
-// normalized before hashing.
-func HashHostname(hostname string) string {
-	// TODO(hanwen): check if we can safely normalize this always.
-	salt := make([]byte, sha1.Size)
-
-	_, err := rand.Read(salt)
-	if err != nil {
-		panic(fmt.Sprintf("crypto/rand failure %v", err))
-	}
-
-	hash := hashHost(hostname, salt)
-	return encodeHash(sha1HashType, salt, hash)
-}
-
-func decodeHash(encoded string) (hashType string, salt, hash []byte, err error) {
-	if len(encoded) == 0 || encoded[0] != '|' {
-		err = errors.New("knownhosts: hashed host must start with '|'")
-		return
-	}
-	components := strings.Split(encoded, "|")
-	if len(components) != 4 {
-		err = fmt.Errorf("knownhosts: got %d components, want 3", len(components))
-		return
-	}
-
-	hashType = components[1]
-	if salt, err = base64.StdEncoding.DecodeString(components[2]); err != nil {
-		return
-	}
-	if hash, err = base64.StdEncoding.DecodeString(components[3]); err != nil {
-		return
-	}
-	return
-}
-
-func encodeHash(typ string, salt []byte, hash []byte) string {
-	return strings.Join([]string{"",
-		typ,
-		base64.StdEncoding.EncodeToString(salt),
-		base64.StdEncoding.EncodeToString(hash),
-	}, "|")
-}
-
-// See https://android.googlesource.com/platform/external/openssh/+/ab28f5495c85297e7a597c1ba62e996416da7c7e/hostfile.c#120
-func hashHost(hostname string, salt []byte) []byte {
-	mac := hmac.New(sha1.New, salt)
-	mac.Write([]byte(hostname))
-	return mac.Sum(nil)
-}
-
-type hashedHost struct {
-	salt []byte
-	hash []byte
-}
-
-const sha1HashType = "1"
-
-func newHashedHost(encoded string) (*hashedHost, error) {
-	typ, salt, hash, err := decodeHash(encoded)
-	if err != nil {
-		return nil, err
-	}
-
-	// The type field seems for future algorithm agility, but it's
-	// actually hardcoded in openssh currently, see
-	// https://android.googlesource.com/platform/external/openssh/+/ab28f5495c85297e7a597c1ba62e996416da7c7e/hostfile.c#120
-	if typ != sha1HashType {
-		return nil, fmt.Errorf("knownhosts: got hash type %s, must be '1'", typ)
-	}
-
-	return &hashedHost{salt: salt, hash: hash}, nil
-}
-
-func (h *hashedHost) match(addrs []addr) bool {
-	for _, a := range addrs {
-		if bytes.Equal(hashHost(Normalize(a.String()), h.salt), h.hash) {
-			return true
-		}
-	}
-	return false
-}
diff --git a/vendor/golang.org/x/crypto/ssh/server.go b/vendor/golang.org/x/crypto/ssh/server.go
index d4df9160..d0f48253 100644
--- a/vendor/golang.org/x/crypto/ssh/server.go
+++ b/vendor/golang.org/x/crypto/ssh/server.go
@@ -166,6 +166,9 @@ type ServerConn struct {
 // unsuccessful, it closes the connection and returns an error.  The
 // Request and NewChannel channels must be serviced, or the connection
 // will hang.
+//
+// The returned error may be of type *ServerAuthError for
+// authentication errors.
 func NewServerConn(c net.Conn, config *ServerConfig) (*ServerConn, <-chan NewChannel, <-chan *Request, error) {
 	fullConf := *config
 	fullConf.SetDefaults()
@@ -256,7 +259,7 @@ func (s *connection) serverHandshake(config *ServerConfig) (*Permissions, error)
 func isAcceptableAlgo(algo string) bool {
 	switch algo {
 	case KeyAlgoRSA, KeyAlgoDSA, KeyAlgoECDSA256, KeyAlgoECDSA384, KeyAlgoECDSA521, KeyAlgoED25519,
-		CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01:
+		CertAlgoRSAv01, CertAlgoDSAv01, CertAlgoECDSA256v01, CertAlgoECDSA384v01, CertAlgoECDSA521v01, CertAlgoED25519v01:
 		return true
 	}
 	return false
@@ -292,12 +295,13 @@ func checkSourceAddress(addr net.Addr, sourceAddrs string) error {
 	return fmt.Errorf("ssh: remote address %v is not allowed because of source-address restriction", addr)
 }
 
-// ServerAuthError implements the error interface. It appends any authentication
-// errors that may occur, and is returned if all of the authentication methods
-// provided by the user failed to authenticate.
+// ServerAuthError represents server authentication errors and is
+// sometimes returned by NewServerConn. It appends any authentication
+// errors that may occur, and is returned if all of the authentication
+// methods provided by the user failed to authenticate.
 type ServerAuthError struct {
 	// Errors contains authentication errors returned by the authentication
-	// callback methods.
+	// callback methods. The first entry is typically ErrNoAuth.
 	Errors []error
 }
 
@@ -309,6 +313,13 @@ func (l ServerAuthError) Error() string {
 	return "[" + strings.Join(errs, ", ") + "]"
 }
 
+// ErrNoAuth is the error value returned if no
+// authentication method has been passed yet. This happens as a normal
+// part of the authentication loop, since the client first tries
+// 'none' authentication to discover available methods.
+// It is returned in ServerAuthError.Errors from NewServerConn.
+var ErrNoAuth = errors.New("ssh: no auth passed yet")
+
 func (s *connection) serverAuthenticate(config *ServerConfig) (*Permissions, error) {
 	sessionID := s.transport.getSessionID()
 	var cache pubKeyCache
@@ -363,7 +374,7 @@ userAuthLoop:
 		}
 
 		perms = nil
-		authErr := errors.New("no auth passed yet")
+		authErr := ErrNoAuth
 
 		switch userAuthReq.Method {
 		case "none":
diff --git a/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go b/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
index 92944f3b..4933ac36 100644
--- a/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
+++ b/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
@@ -93,5 +93,13 @@ func ReadPassword(fd int) ([]byte, error) {
 		windows.SetConsoleMode(windows.Handle(fd), old)
 	}()
 
-	return readPasswordLine(os.NewFile(uintptr(fd), "stdin"))
+	var h windows.Handle
+	p, _ := windows.GetCurrentProcess()
+	if err := windows.DuplicateHandle(p, windows.Handle(fd), p, &h, 0, false, windows.DUPLICATE_SAME_ACCESS); err != nil {
+		return nil, err
+	}
+
+	f := os.NewFile(uintptr(h), "stdin")
+	defer f.Close()
+	return readPasswordLine(f)
 }
diff --git a/vendor/golang.org/x/crypto/ssh/test/doc.go b/vendor/golang.org/x/crypto/ssh/test/doc.go
deleted file mode 100644
index 198f0ca1..00000000
--- a/vendor/golang.org/x/crypto/ssh/test/doc.go
+++ /dev/null
@@ -1,7 +0,0 @@
-// Copyright 2012 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 contains integration tests for the
-// golang.org/x/crypto/ssh package.
-package test // import "golang.org/x/crypto/ssh/test"
diff --git a/vendor/golang.org/x/crypto/ssh/transport.go b/vendor/golang.org/x/crypto/ssh/transport.go
index 01150eb8..f6fae1db 100644
--- a/vendor/golang.org/x/crypto/ssh/transport.go
+++ b/vendor/golang.org/x/crypto/ssh/transport.go
@@ -6,6 +6,7 @@ package ssh
 
 import (
 	"bufio"
+	"bytes"
 	"errors"
 	"io"
 	"log"
@@ -232,52 +233,22 @@ var (
 	clientKeys = direction{[]byte{'A'}, []byte{'C'}, []byte{'E'}}
 )
 
-// generateKeys generates key material for IV, MAC and encryption.
-func generateKeys(d direction, algs directionAlgorithms, kex *kexResult) (iv, key, macKey []byte) {
+// setupKeys sets the cipher and MAC keys from kex.K, kex.H and sessionId, as
+// described in RFC 4253, section 6.4. direction should either be serverKeys
+// (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)
+	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)
-	return
-}
-
-// setupKeys sets the cipher and MAC keys from kex.K, kex.H and sessionId, as
-// described in RFC 4253, section 6.4. direction should either be serverKeys
-// (to setup server->client keys) or clientKeys (for client->server keys).
-func newPacketCipher(d direction, algs directionAlgorithms, kex *kexResult) (packetCipher, error) {
-	iv, key, macKey := generateKeys(d, algs, kex)
-
-	if algs.Cipher == gcmCipherID {
-		return newGCMCipher(iv, key)
-	}
-
-	if algs.Cipher == aes128cbcID {
-		return newAESCBCCipher(iv, key, macKey, algs)
-	}
 
-	if algs.Cipher == tripledescbcID {
-		return newTripleDESCBCCipher(iv, key, macKey, algs)
-	}
-
-	c := &streamPacketCipher{
-		mac: macModes[algs.MAC].new(macKey),
-		etm: macModes[algs.MAC].etm,
-	}
-	c.macResult = make([]byte, c.mac.Size())
-
-	var err error
-	c.cipher, err = cipherModes[algs.Cipher].createStream(key, iv)
-	if err != nil {
-		return nil, err
-	}
-
-	return c, nil
+	return cipherModes[algs.Cipher].create(key, iv, macKey, algs)
 }
 
 // generateKeyMaterial fills out with key material generated from tag, K, H
@@ -342,7 +313,7 @@ func readVersion(r io.Reader) ([]byte, error) {
 	var ok bool
 	var buf [1]byte
 
-	for len(versionString) < maxVersionStringBytes {
+	for length := 0; length < maxVersionStringBytes; length++ {
 		_, err := io.ReadFull(r, buf[:])
 		if err != nil {
 			return nil, err
@@ -350,6 +321,13 @@ func readVersion(r io.Reader) ([]byte, error) {
 		// The RFC says that the version should be terminated with \r\n
 		// but several SSH servers actually only send a \n.
 		if buf[0] == '\n' {
+			if !bytes.HasPrefix(versionString, []byte("SSH-")) {
+				// RFC 4253 says we need to ignore all version string lines
+				// except the one containing the SSH version (provided that
+				// all the lines do not exceed 255 bytes in total).
+				versionString = versionString[:0]
+				continue
+			}
 			ok = true
 			break
 		}