Update vendored library golang.org/x/crypto

2024-06-01 08:30:49 +00:00 · 2018-03-30 12:26:26 +02:00 · 2018-03-30 12:26:26 +02:00 · 7e6fff324c
commit 7e6fff324c
parent e94d2da890
38 changed files with 1203 additions and 223 deletions
--- a/Gopkg.lock
+++ b/Gopkg.lock
@ -179,7 +179,7 @@
  branch = "master"
  name = "golang.org/x/crypto"
  packages = ["curve25519","ed25519","ed25519/internal/edwards25519","internal/chacha20","pbkdf2","poly1305","scrypt","ssh","ssh/terminal"]
-  revision = "3d37316aaa6bd9929127ac9a527abf408178ea7b"
+  revision = "88942b9c40a4c9d203b82b3731787b672d6e809b"

 [[projects]]
  branch = "master"
--- a/vendor/golang.org/x/crypto/CONTRIBUTING.md
+++ b/vendor/golang.org/x/crypto/CONTRIBUTING.md
@ -4,7 +4,6 @@ Go is an open source project.

 It is the work of hundreds of contributors. We appreciate your help!

-
 ## Filing issues

 When [filing an issue](https://golang.org/issue/new), make sure to answer these five questions:
@ -23,9 +22,5 @@ The gophers there will answer or ask you to file an issue if you've tripped over
 Please read the [Contribution Guidelines](https://golang.org/doc/contribute.html)
 before sending patches.

-**We do not accept GitHub pull requests**
-(we use [Gerrit](https://code.google.com/p/gerrit/) instead for code review).
-
 Unless otherwise noted, the Go source files are distributed under
 the BSD-style license found in the LICENSE file.
-
--- a/vendor/golang.org/x/crypto/acme/acme.go
+++ b/vendor/golang.org/x/crypto/acme/acme.go
@ -400,7 +400,7 @@ func (c *Client) RevokeAuthorization(ctx context.Context, url string) error {

 // WaitAuthorization polls an authorization at the given URL
 // until it is in one of the final states, StatusValid or StatusInvalid,
-// or the context is done.
+// the ACME CA responded with a 4xx error code, or the context is done.
 //
 // It returns a non-nil Authorization only if its Status is StatusValid.
 // In all other cases WaitAuthorization returns an error.
@ -412,6 +412,13 @@ func (c *Client) WaitAuthorization(ctx context.Context, url string) (*Authorizat
 		if err != nil {
 			return nil, err
 		}
+		if res.StatusCode >= 400 && res.StatusCode <= 499 {
+			// Non-retriable error. For instance, Let's Encrypt may return 404 Not Found
+			// when requesting an expired authorization.
+			defer res.Body.Close()
+			return nil, responseError(res)
+		}
+
 		retry := res.Header.Get("Retry-After")
 		if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusAccepted {
 			res.Body.Close()
--- a/vendor/golang.org/x/crypto/acme/acme_test.go
+++ b/vendor/golang.org/x/crypto/acme/acme_test.go
@ -549,6 +549,34 @@ func TestWaitAuthorizationInvalid(t *testing.T) {
 	}
 }

+func TestWaitAuthorizationClientError(t *testing.T) {
+	const code = http.StatusBadRequest
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(code)
+	}))
+	defer ts.Close()
+
+	ch := make(chan error, 1)
+	go func() {
+		var client Client
+		_, err := client.WaitAuthorization(context.Background(), ts.URL)
+		ch <- err
+	}()
+
+	select {
+	case <-time.After(3 * time.Second):
+		t.Fatal("WaitAuthz took too long to return")
+	case err := <-ch:
+		res, ok := err.(*Error)
+		if !ok {
+			t.Fatalf("err is %v (%T); want a non-nil *Error", err, err)
+		}
+		if res.StatusCode != code {
+			t.Errorf("res.StatusCode = %d; want %d", res.StatusCode, code)
+		}
+	}
+}
+
 func TestWaitAuthorizationCancel(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Retry-After", "60")
--- a/vendor/golang.org/x/crypto/acme/autocert/autocert.go
+++ b/vendor/golang.org/x/crypto/acme/autocert/autocert.go
@ -27,7 +27,6 @@ import (
 	"net"
 	"net/http"
 	"path"
-	"strconv"
 	"strings"
 	"sync"
 	"time"
@ -942,16 +941,6 @@ func validCert(domain string, der [][]byte, key crypto.Signer) (leaf *x509.Certi
 	return leaf, nil
 }

-func retryAfter(v string) time.Duration {
-	if i, err := strconv.Atoi(v); err == nil {
-		return time.Duration(i) * time.Second
-	}
-	if t, err := http.ParseTime(v); err == nil {
-		return t.Sub(timeNow())
-	}
-	return time.Second
-}
-
 type lockedMathRand struct {
 	sync.Mutex
 	rnd *mathrand.Rand
--- a/vendor/golang.org/x/crypto/acme/autocert/renewal.go
+++ b/vendor/golang.org/x/crypto/acme/autocert/renewal.go
@ -71,12 +71,21 @@ func (dr *domainRenewal) renew() {
 	testDidRenewLoop(next, err)
 }

+// updateState locks and replaces the relevant Manager.state item with the given
+// state. It additionally updates dr.key with the given state's key.
+func (dr *domainRenewal) updateState(state *certState) {
+	dr.m.stateMu.Lock()
+	defer dr.m.stateMu.Unlock()
+	dr.key = state.key
+	dr.m.state[dr.domain] = state
+}
+
 // do is similar to Manager.createCert but it doesn't lock a Manager.state item.
 // Instead, it requests a new certificate independently and, upon success,
 // replaces dr.m.state item with a new one and updates cache for the given domain.
 //
-// It may return immediately if the expiration date of the currently cached cert
-// is far enough in the future.
+// It may lock and update the Manager.state if the expiration date of the currently
+// cached cert is far enough in the future.
 //
 // The returned value is a time interval after which the renewal should occur again.
 func (dr *domainRenewal) do(ctx context.Context) (time.Duration, error) {
@ -85,9 +94,18 @@ func (dr *domainRenewal) do(ctx context.Context) (time.Duration, error) {
 	if tlscert, err := dr.m.cacheGet(ctx, dr.domain); err == nil {
 		next := dr.next(tlscert.Leaf.NotAfter)
 		if next > dr.m.renewBefore()+renewJitter {
+			signer, ok := tlscert.PrivateKey.(crypto.Signer)
+			if ok {
+				state := &certState{
+					key:  signer,
+					cert: tlscert.Certificate,
+					leaf: tlscert.Leaf,
+				}
+				dr.updateState(state)
 				return next, nil
 			}
 		}
+	}

 	der, leaf, err := dr.m.authorizedCert(ctx, dr.key, dr.domain)
 	if err != nil {
@ -102,11 +120,10 @@ func (dr *domainRenewal) do(ctx context.Context) (time.Duration, error) {
 	if err != nil {
 		return 0, err
 	}
-	dr.m.cachePut(ctx, dr.domain, tlscert)
-	dr.m.stateMu.Lock()
-	defer dr.m.stateMu.Unlock()
-	// m.state is guaranteed to be non-nil at this point
-	dr.m.state[dr.domain] = state
+	if err := dr.m.cachePut(ctx, dr.domain, tlscert); err != nil {
+		return 0, err
+	}
+	dr.updateState(state)
 	return dr.next(leaf.NotAfter), nil
 }

--- a/vendor/golang.org/x/crypto/acme/autocert/renewal_test.go
+++ b/vendor/golang.org/x/crypto/acme/autocert/renewal_test.go
@ -189,3 +189,149 @@ func TestRenewFromCache(t *testing.T) {
 	case <-done:
 	}
 }
+
+func TestRenewFromCacheAlreadyRenewed(t *testing.T) {
+	const domain = "example.org"
+
+	// use EC key to run faster on 386
+	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	man := &Manager{
+		Prompt:      AcceptTOS,
+		Cache:       newMemCache(),
+		RenewBefore: 24 * time.Hour,
+		Client: &acme.Client{
+			Key:          key,
+			DirectoryURL: "invalid",
+		},
+	}
+	defer man.stopRenew()
+
+	// cache a recently renewed cert with a different private key
+	newKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	now := time.Now()
+	newCert, err := dateDummyCert(newKey.Public(), now.Add(-2*time.Hour), now.Add(time.Hour*24*90), domain)
+	if err != nil {
+		t.Fatal(err)
+	}
+	newLeaf, err := validCert(domain, [][]byte{newCert}, newKey)
+	if err != nil {
+		t.Fatal(err)
+	}
+	newTLSCert := &tls.Certificate{PrivateKey: newKey, Certificate: [][]byte{newCert}, Leaf: newLeaf}
+	if err := man.cachePut(context.Background(), domain, newTLSCert); err != nil {
+		t.Fatal(err)
+	}
+
+	// set internal state to an almost expired cert
+	oldCert, err := dateDummyCert(key.Public(), now.Add(-2*time.Hour), now.Add(time.Minute), domain)
+	if err != nil {
+		t.Fatal(err)
+	}
+	oldLeaf, err := validCert(domain, [][]byte{oldCert}, key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	man.stateMu.Lock()
+	if man.state == nil {
+		man.state = make(map[string]*certState)
+	}
+	s := &certState{
+		key:  key,
+		cert: [][]byte{oldCert},
+		leaf: oldLeaf,
+	}
+	man.state[domain] = s
+	man.stateMu.Unlock()
+
+	// veriy the renewal accepted the newer cached cert
+	defer func() {
+		testDidRenewLoop = func(next time.Duration, err error) {}
+	}()
+	done := make(chan struct{})
+	testDidRenewLoop = func(next time.Duration, err error) {
+		defer close(done)
+		if err != nil {
+			t.Errorf("testDidRenewLoop: %v", err)
+		}
+		// Next should be about 90 days
+		// Previous expiration was within 1 min.
+		future := 88 * 24 * time.Hour
+		if next < future {
+			t.Errorf("testDidRenewLoop: next = %v; want >= %v", next, future)
+		}
+
+		// ensure the cached cert was not modified
+		tlscert, err := man.cacheGet(context.Background(), domain)
+		if err != nil {
+			t.Fatalf("man.cacheGet: %v", err)
+		}
+		if !tlscert.Leaf.NotAfter.Equal(newLeaf.NotAfter) {
+			t.Errorf("cache leaf.NotAfter = %v; want == %v", tlscert.Leaf.NotAfter, newLeaf.NotAfter)
+		}
+
+		// verify the old cert is also replaced in memory
+		man.stateMu.Lock()
+		defer man.stateMu.Unlock()
+		s := man.state[domain]
+		if s == nil {
+			t.Fatalf("m.state[%q] is nil", domain)
+		}
+		stateKey := s.key.Public().(*ecdsa.PublicKey)
+		if stateKey.X.Cmp(newKey.X) != 0 || stateKey.Y.Cmp(newKey.Y) != 0 {
+			t.Fatalf("state key was not updated from cache x: %v y: %v; want x: %v y: %v", stateKey.X, stateKey.Y, newKey.X, newKey.Y)
+		}
+		tlscert, err = s.tlscert()
+		if err != nil {
+			t.Fatalf("s.tlscert: %v", err)
+		}
+		if !tlscert.Leaf.NotAfter.Equal(newLeaf.NotAfter) {
+			t.Errorf("state leaf.NotAfter = %v; want == %v", tlscert.Leaf.NotAfter, newLeaf.NotAfter)
+		}
+
+		// verify the private key is replaced in the renewal state
+		r := man.renewal[domain]
+		if r == nil {
+			t.Fatalf("m.renewal[%q] is nil", domain)
+		}
+		renewalKey := r.key.Public().(*ecdsa.PublicKey)
+		if renewalKey.X.Cmp(newKey.X) != 0 || renewalKey.Y.Cmp(newKey.Y) != 0 {
+			t.Fatalf("renewal private key was not updated from cache x: %v y: %v; want x: %v y: %v", renewalKey.X, renewalKey.Y, newKey.X, newKey.Y)
+		}
+
+	}
+
+	// assert the expiring cert is returned from state
+	hello := &tls.ClientHelloInfo{ServerName: domain}
+	tlscert, err := man.GetCertificate(hello)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !oldLeaf.NotAfter.Equal(tlscert.Leaf.NotAfter) {
+		t.Errorf("state leaf.NotAfter = %v; want == %v", tlscert.Leaf.NotAfter, oldLeaf.NotAfter)
+	}
+
+	// trigger renew
+	go man.renew(domain, s.key, s.leaf.NotAfter)
+
+	// wait for renew loop
+	select {
+	case <-time.After(10 * time.Second):
+		t.Fatal("renew took too long to occur")
+	case <-done:
+		// assert the new cert is returned from state after renew
+		hello := &tls.ClientHelloInfo{ServerName: domain}
+		tlscert, err := man.GetCertificate(hello)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !newTLSCert.Leaf.NotAfter.Equal(tlscert.Leaf.NotAfter) {
+			t.Errorf("state leaf.NotAfter = %v; want == %v", tlscert.Leaf.NotAfter, newTLSCert.Leaf.NotAfter)
+		}
+	}
+}
--- a/vendor/golang.org/x/crypto/argon2/argon2.go
+++ b/vendor/golang.org/x/crypto/argon2/argon2.go
@ -5,7 +5,35 @@
 // Package argon2 implements the key derivation function Argon2.
 // Argon2 was selected as the winner of the Password Hashing Competition and can
 // be used to derive cryptographic keys from passwords.
-// Argon2 is specfifed at https://github.com/P-H-C/phc-winner-argon2/blob/master/argon2-specs.pdf
+//
+// For a detailed specification of Argon2 see [1].
+//
+// If you aren't sure which function you need, use Argon2id (IDKey) and
+// the parameter recommendations for your scenario.
+//
+//
+// Argon2i
+//
+// Argon2i (implemented by Key) is the side-channel resistant version of Argon2.
+// It uses data-independent memory access, which is preferred for password
+// hashing and password-based key derivation. Argon2i requires more passes over
+// memory than Argon2id to protect from trade-off attacks. The recommended
+// parameters (taken from [2]) for non-interactive operations are time=3 and to
+// use the maximum available memory.
+//
+//
+// Argon2id
+//
+// Argon2id (implemented by IDKey) is a hybrid version of Argon2 combining
+// Argon2i and Argon2d. It uses data-independent memory access for the first
+// half of the first iteration over the memory and data-dependent memory access
+// for the rest. Argon2id is side-channel resistant and provides better brute-
+// force cost savings due to time-memory tradeoffs than Argon2i. The recommended
+// parameters for non-interactive operations (taken from [2]) are time=1 and to
+// use the maximum available memory.
+//
+// [1] https://github.com/P-H-C/phc-winner-argon2/blob/master/argon2-specs.pdf
+// [2] https://tools.ietf.org/html/draft-irtf-cfrg-argon2-03#section-9.3
 package argon2

 import (
@ -25,23 +53,52 @@ const (
 )

 // Key derives a key from the password, salt, and cost parameters using Argon2i
-// returning a byte slice of length keyLen that can be used as cryptographic key.
-// The CPU cost and parallism degree must be greater than zero.
+// returning a byte slice of length keyLen that can be used as cryptographic
+// key. The CPU cost and parallelism degree must be greater than zero.
 //
-// For example, you can get a derived key for e.g. AES-256 (which needs a 32-byte key) by doing:
-// `key := argon2.Key([]byte("some password"), salt, 4, 32*1024, 4, 32)`
+// For example, you can get a derived key for e.g. AES-256 (which needs a
+// 32-byte key) by doing:
 //
-// The recommended parameters for interactive logins as of 2017 are time=4, memory=32*1024.
-// The number of threads can be adjusted to the numbers of available CPUs.
-// The time parameter specifies the number of passes over the memory and the memory
-// parameter specifies the size of the memory in KiB. For example memory=32*1024 sets the
-// memory cost to ~32 MB.
-// The cost parameters should be increased as memory latency and CPU parallelism increases.
-// Remember to get a good random salt.
+//      key := argon2.Key([]byte("some password"), salt, 3, 32*1024, 4, 32)
+//
+// The draft RFC recommends[2] time=3, and memory=32*1024 is a sensible number.
+// If using that amount of memory (32 MB) is not possible in some contexts then
+// the time parameter can be increased to compensate.
+//
+// The time parameter specifies the number of passes over the memory and the
+// memory parameter specifies the size of the memory in KiB. For example
+// memory=32*1024 sets the memory cost to ~32 MB. The number of threads can be
+// adjusted to the number of available CPUs. The cost parameters should be
+// increased as memory latency and CPU parallelism increases. Remember to get a
+// good random salt.
 func Key(password, salt []byte, time, memory uint32, threads uint8, keyLen uint32) []byte {
 	return deriveKey(argon2i, password, salt, nil, nil, time, memory, threads, keyLen)
 }

+// IDKey derives a key from the password, salt, and cost parameters using
+// Argon2id returning a byte slice of length keyLen that can be used as
+// cryptographic key. The CPU cost and parallelism degree must be greater than
+// zero.
+//
+// For example, you can get a derived key for e.g. AES-256 (which needs a
+// 32-byte key) by doing:
+//
+//      key := argon2.IDKey([]byte("some password"), salt, 1, 64*1024, 4, 32)
+//
+// The draft RFC recommends[2] time=1, and memory=64*1024 is a sensible number.
+// If using that amount of memory (64 MB) is not possible in some contexts then
+// the time parameter can be increased to compensate.
+//
+// The time parameter specifies the number of passes over the memory and the
+// memory parameter specifies the size of the memory in KiB. For example
+// memory=64*1024 sets the memory cost to ~64 MB. The number of threads can be
+// adjusted to the numbers of available CPUs. The cost parameters should be
+// increased as memory latency and CPU parallelism increases. Remember to get a
+// good random salt.
+func IDKey(password, salt []byte, time, memory uint32, threads uint8, keyLen uint32) []byte {
+	return deriveKey(argon2id, password, salt, nil, nil, time, memory, threads, keyLen)
+}
+
 func deriveKey(mode int, password, salt, secret, data []byte, time, memory uint32, threads uint8, keyLen uint32) []byte {
 	if time < 1 {
 		panic("argon2: number of rounds too small")
--- a/vendor/golang.org/x/crypto/ed25519/ed25519.go
+++ b/vendor/golang.org/x/crypto/ed25519/ed25519.go
@ -171,9 +171,16 @@ func Verify(publicKey PublicKey, message, sig []byte) bool {
 	edwards25519.ScReduce(&hReduced, &digest)

 	var R edwards25519.ProjectiveGroupElement
-	var b [32]byte
-	copy(b[:], sig[32:])
-	edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &b)
+	var s [32]byte
+	copy(s[:], sig[32:])
+
+	// https://tools.ietf.org/html/rfc8032#section-5.1.7 requires that s be in
+	// the range [0, order) in order to prevent signature malleability.
+	if !edwards25519.ScMinimal(&s) {
+		return false
+	}
+
+	edwards25519.GeDoubleScalarMultVartime(&R, &hReduced, &A, &s)

 	var checkR [32]byte
 	R.ToBytes(&checkR)
--- a/vendor/golang.org/x/crypto/ed25519/ed25519_test.go
+++ b/vendor/golang.org/x/crypto/ed25519/ed25519_test.go
@ -146,6 +146,30 @@ func TestGolden(t *testing.T) {
 	}
 }

+func TestMalleability(t *testing.T) {
+	// https://tools.ietf.org/html/rfc8032#section-5.1.7 adds an additional test
+	// that s be in [0, order). This prevents someone from adding a multiple of
+	// order to s and obtaining a second valid signature for the same message.
+	msg := []byte{0x54, 0x65, 0x73, 0x74}
+	sig := []byte{
+		0x7c, 0x38, 0xe0, 0x26, 0xf2, 0x9e, 0x14, 0xaa, 0xbd, 0x05, 0x9a,
+		0x0f, 0x2d, 0xb8, 0xb0, 0xcd, 0x78, 0x30, 0x40, 0x60, 0x9a, 0x8b,
+		0xe6, 0x84, 0xdb, 0x12, 0xf8, 0x2a, 0x27, 0x77, 0x4a, 0xb0, 0x67,
+		0x65, 0x4b, 0xce, 0x38, 0x32, 0xc2, 0xd7, 0x6f, 0x8f, 0x6f, 0x5d,
+		0xaf, 0xc0, 0x8d, 0x93, 0x39, 0xd4, 0xee, 0xf6, 0x76, 0x57, 0x33,
+		0x36, 0xa5, 0xc5, 0x1e, 0xb6, 0xf9, 0x46, 0xb3, 0x1d,
+	}
+	publicKey := []byte{
+		0x7d, 0x4d, 0x0e, 0x7f, 0x61, 0x53, 0xa6, 0x9b, 0x62, 0x42, 0xb5,
+		0x22, 0xab, 0xbe, 0xe6, 0x85, 0xfd, 0xa4, 0x42, 0x0f, 0x88, 0x34,
+		0xb1, 0x08, 0xc3, 0xbd, 0xae, 0x36, 0x9e, 0xf5, 0x49, 0xfa,
+	}
+
+	if Verify(publicKey, msg, sig) {
+		t.Fatal("non-canonical signature accepted")
+	}
+}
+
 func BenchmarkKeyGeneration(b *testing.B) {
 	var zero zeroReader
 	for i := 0; i < b.N; i++ {
--- a/vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go
+++ b/vendor/golang.org/x/crypto/ed25519/internal/edwards25519/edwards25519.go
@ -4,6 +4,8 @@

 package edwards25519

+import "encoding/binary"
+
 // This code is a port of the public domain, “ref10” implementation of ed25519
 // from SUPERCOP.

@ -1769,3 +1771,23 @@ func ScReduce(out *[32]byte, s *[64]byte) {
 	out[30] = byte(s11 >> 9)
 	out[31] = byte(s11 >> 17)
 }
+
+// order is the order of Curve25519 in little-endian form.
+var order = [4]uint64{0x5812631a5cf5d3ed, 0x14def9dea2f79cd6, 0, 0x1000000000000000}
+
+// ScMinimal returns true if the given scalar is less than the order of the
+// curve.
+func ScMinimal(scalar *[32]byte) bool {
+	for i := 3; ; i-- {
+		v := binary.LittleEndian.Uint64(scalar[i*8:])
+		if v > order[i] {
+			return false
+		} else if v < order[i] {
+			break
+		} else if i == 0 {
+			return false
+		}
+	}
+
+	return true
+}
--- a/vendor/golang.org/x/crypto/nacl/sign/sign.go
+++ b/vendor/golang.org/x/crypto/nacl/sign/sign.go
@ -0,0 +1,83 @@
+// Copyright 2018 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 sign signs small messages using public-key cryptography.
+//
+// Sign uses Ed25519 to sign messages. The length of messages is not hidden.
+// Messages should be small because:
+// 1. The whole message needs to be held in memory to be processed.
+// 2. Using large messages pressures implementations on small machines to process
+// plaintext without verifying the signature. This is very dangerous, and this API
+// discourages it, but a protocol that uses excessive message sizes might present
+// some implementations with no other choice.
+// 3. Performance may be improved by working with messages that fit into data caches.
+// Thus large amounts of data should be chunked so that each message is small.
+//
+// This package is not interoperable with the current release of NaCl
+// (https://nacl.cr.yp.to/sign.html), which does not support Ed25519 yet. However,
+// it is compatible with the NaCl fork libsodium (https://www.libsodium.org), as well
+// as TweetNaCl (https://tweetnacl.cr.yp.to/).
+package sign
+
+import (
+	"io"
+
+	"golang.org/x/crypto/ed25519"
+)
+
+// Overhead is the number of bytes of overhead when signing a message.
+const Overhead = 64
+
+// GenerateKey generates a new public/private key pair suitable for use with
+// Sign and Open.
+func GenerateKey(rand io.Reader) (publicKey *[32]byte, privateKey *[64]byte, err error) {
+	pub, priv, err := ed25519.GenerateKey(rand)
+	if err != nil {
+		return nil, nil, err
+	}
+	publicKey, privateKey = new([32]byte), new([64]byte)
+	copy((*publicKey)[:], pub)
+	copy((*privateKey)[:], priv)
+	return publicKey, privateKey, nil
+}
+
+// Sign appends a signed copy of message to out, which will be Overhead bytes
+// longer than the original and must not overlap it.
+func Sign(out, message []byte, privateKey *[64]byte) []byte {
+	sig := ed25519.Sign(ed25519.PrivateKey((*privateKey)[:]), message)
+	ret, out := sliceForAppend(out, Overhead+len(message))
+	copy(out, sig)
+	copy(out[Overhead:], message)
+	return ret
+}
+
+// Open verifies a signed message produced by Sign and appends the message to
+// out, which must not overlap the signed message. The output will be Overhead
+// bytes smaller than the signed message.
+func Open(out, signedMessage []byte, publicKey *[32]byte) ([]byte, bool) {
+	if len(signedMessage) < Overhead {
+		return nil, false
+	}
+	if !ed25519.Verify(ed25519.PublicKey((*publicKey)[:]), signedMessage[Overhead:], signedMessage[:Overhead]) {
+		return nil, false
+	}
+	ret, out := sliceForAppend(out, len(signedMessage)-Overhead)
+	copy(out, signedMessage[Overhead:])
+	return ret, true
+}
+
+// sliceForAppend takes a slice and a requested number of bytes. It returns a
+// slice with the contents of the given slice followed by that many bytes and a
+// second slice that aliases into it and contains only the extra bytes. If the
+// original slice has sufficient capacity then no allocation is performed.
+func sliceForAppend(in []byte, n int) (head, tail []byte) {
+	if total := len(in) + n; cap(in) >= total {
+		head = in[:total]
+	} else {
+		head = make([]byte, total)
+		copy(head, in)
+	}
+	tail = head[len(in):]
+	return
+}
--- a/vendor/golang.org/x/crypto/nacl/sign/sign_test.go
+++ b/vendor/golang.org/x/crypto/nacl/sign/sign_test.go
@ -0,0 +1,74 @@
+// Copyright 2018 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 sign
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"testing"
+)
+
+var testSignedMessage, _ = hex.DecodeString("26a0a47f733d02ddb74589b6cbd6f64a7dab1947db79395a1a9e00e4c902c0f185b119897b89b248d16bab4ea781b5a3798d25c2984aec833dddab57e0891e0d68656c6c6f20776f726c64")
+var testMessage = testSignedMessage[Overhead:]
+var testPublicKey [32]byte
+var testPrivateKey = [64]byte{
+	0x98, 0x3c, 0x6a, 0xa6, 0x21, 0xcc, 0xbb, 0xb2, 0xa7, 0xe8, 0x97, 0x94, 0xde, 0x5f, 0xf8, 0x11,
+	0x8a, 0xf3, 0x33, 0x1a, 0x03, 0x5c, 0x43, 0x99, 0x03, 0x13, 0x2d, 0xd7, 0xb4, 0xc4, 0x8b, 0xb0,
+	0xf6, 0x33, 0x20, 0xa3, 0x34, 0x8b, 0x7b, 0xe2, 0xfe, 0xb4, 0xe7, 0x3a, 0x54, 0x08, 0x2d, 0xd7,
+	0x0c, 0xb7, 0xc0, 0xe3, 0xbf, 0x62, 0x6c, 0x55, 0xf0, 0x33, 0x28, 0x52, 0xf8, 0x48, 0x7d, 0xfd,
+}
+
+func init() {
+	copy(testPublicKey[:], testPrivateKey[32:])
+}
+
+func TestSign(t *testing.T) {
+	signedMessage := Sign(nil, testMessage, &testPrivateKey)
+	if !bytes.Equal(signedMessage, testSignedMessage) {
+		t.Fatalf("signed message did not match, got\n%x\n, expected\n%x", signedMessage, testSignedMessage)
+	}
+}
+
+func TestOpen(t *testing.T) {
+	message, ok := Open(nil, testSignedMessage, &testPublicKey)
+	if !ok {
+		t.Fatalf("valid signed message not successfully verified")
+	}
+	if !bytes.Equal(message, testMessage) {
+		t.Fatalf("message did not match, got\n%x\n, expected\n%x", message, testMessage)
+	}
+	message, ok = Open(nil, testSignedMessage[1:], &testPublicKey)
+	if ok {
+		t.Fatalf("invalid signed message successfully verified")
+	}
+
+	badMessage := make([]byte, len(testSignedMessage))
+	copy(badMessage, testSignedMessage)
+	badMessage[5] ^= 1
+	if _, ok := Open(nil, badMessage, &testPublicKey); ok {
+		t.Fatalf("Open succeeded with a corrupt message")
+	}
+
+	var badPublicKey [32]byte
+	copy(badPublicKey[:], testPublicKey[:])
+	badPublicKey[5] ^= 1
+	if _, ok := Open(nil, testSignedMessage, &badPublicKey); ok {
+		t.Fatalf("Open succeeded with a corrupt public key")
+	}
+}
+
+func TestGenerateSignOpen(t *testing.T) {
+	publicKey, privateKey, _ := GenerateKey(rand.Reader)
+	signedMessage := Sign(nil, testMessage, privateKey)
+	message, ok := Open(nil, signedMessage, publicKey)
+	if !ok {
+		t.Fatalf("failed to verify signed message")
+	}
+
+	if !bytes.Equal(message, testMessage) {
+		t.Fatalf("verified message does not match signed messge, got\n%x\n, expected\n%x", message, testMessage)
+	}
+}
--- a/vendor/golang.org/x/crypto/openpgp/keys.go
+++ b/vendor/golang.org/x/crypto/openpgp/keys.go
@ -486,7 +486,7 @@ func NewEntity(name, comment, email string, config *packet.Config) (*Entity, err
 	}
 	isPrimaryId := true
 	e.Identities[uid.Id] = &Identity{
-		Name:   uid.Name,
+		Name:   uid.Id,
 		UserId: uid,
 		SelfSignature: &packet.Signature{
 			CreationTime: currentTime,
@ -507,6 +507,11 @@ func NewEntity(name, comment, email string, config *packet.Config) (*Entity, err
 		e.Identities[uid.Id].SelfSignature.PreferredHash = []uint8{hashToHashId(config.DefaultHash)}
 	}

+	// Likewise for DefaultCipher.
+	if config != nil && config.DefaultCipher != 0 {
+		e.Identities[uid.Id].SelfSignature.PreferredSymmetric = []uint8{uint8(config.DefaultCipher)}
+	}
+
 	e.Subkeys = make([]Subkey, 1)
 	e.Subkeys[0] = Subkey{
 		PublicKey:  packet.NewRSAPublicKey(currentTime, &encryptingPriv.PublicKey),
--- a/vendor/golang.org/x/crypto/openpgp/keys_test.go
+++ b/vendor/golang.org/x/crypto/openpgp/keys_test.go
@ -320,6 +320,56 @@ func TestNewEntityWithoutPreferredHash(t *testing.T) {
 	}
 }

+func TestNewEntityCorrectName(t *testing.T) {
+	entity, err := NewEntity("Golang Gopher", "Test Key", "no-reply@golang.com", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(entity.Identities) != 1 {
+		t.Fatalf("len(entity.Identities) = %d, want 1", len(entity.Identities))
+	}
+	var got string
+	for _, i := range entity.Identities {
+		got = i.Name
+	}
+	want := "Golang Gopher (Test Key) <no-reply@golang.com>"
+	if got != want {
+		t.Fatalf("Identity.Name = %q, want %q", got, want)
+	}
+}
+
+func TestNewEntityWithPreferredSymmetric(t *testing.T) {
+	c := &packet.Config{
+		DefaultCipher: packet.CipherAES256,
+	}
+	entity, err := NewEntity("Golang Gopher", "Test Key", "no-reply@golang.com", c)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, identity := range entity.Identities {
+		if len(identity.SelfSignature.PreferredSymmetric) == 0 {
+			t.Fatal("didn't find a preferred cipher in self signature")
+		}
+		if identity.SelfSignature.PreferredSymmetric[0] != uint8(c.DefaultCipher) {
+			t.Fatalf("Expected preferred cipher to be %d, got %d", uint8(c.DefaultCipher), identity.SelfSignature.PreferredSymmetric[0])
+		}
+	}
+}
+
+func TestNewEntityWithoutPreferredSymmetric(t *testing.T) {
+	entity, err := NewEntity("Golang Gopher", "Test Key", "no-reply@golang.com", nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	for _, identity := range entity.Identities {
+		if len(identity.SelfSignature.PreferredSymmetric) != 0 {
+			t.Fatalf("Expected preferred cipher to be empty but got length %d", len(identity.SelfSignature.PreferredSymmetric))
+		}
+	}
+}
+
 const expiringKeyHex = "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"
 const subkeyUsageHex = "988d04533a52bc010400d26af43085558f65b9e7dbc90cb9238015259aed5e954637adcfa2181548b2d0b60c65f1f42ec5081cbf1bc0a8aa4900acfb77070837c58f26012fbce297d70afe96e759ad63531f0037538e70dbf8e384569b9720d99d8eb39d8d0a2947233ed242436cb6ac7dfe74123354b3d0119b5c235d3dd9c9d6c004f8ffaf67ad8583001101000188b7041f010200210502533b8552170c8001ce094aa433f7040bb2ddf0be3893cb843d0fe70c020700000a0910a42704b92866382aa98404009d63d916a27543da4221c60087c33f1c44bec9998c5438018ed370cca4962876c748e94b73eb39c58eb698063f3fd6346d58dd2a11c0247934c4a9d71f24754f7468f96fb24c3e791dd2392b62f626148ad724189498cbf993db2df7c0cdc2d677c35da0f16cb16c9ce7c33b4de65a4a91b1d21a130ae9cc26067718910ef8e2b417556d627261203c756d627261407379642e65642e61753e88b80413010200220502533a52bc021b03060b090807030206150802090a0b0416020301021e01021780000a0910a42704b92866382a47840400c0c2bd04f5fca586de408b395b3c280a278259c93eaaa8b79a53b97003f8ed502a8a00446dd9947fb462677e4fcac0dac2f0701847d15130aadb6cd9e0705ea0cf5f92f129136c7be21a718d46c8e641eb7f044f2adae573e11ae423a0a9ca51324f03a8a2f34b91fa40c3cc764bee4dccadedb54c768ba0469b683ea53f1c29b88d04533a52bc01040099c92a5d6f8b744224da27bc2369127c35269b58bec179de6bbc038f749344222f85a31933224f26b70243c4e4b2d242f0c4777eaef7b5502f9dad6d8bf3aaeb471210674b74de2d7078af497d55f5cdad97c7bedfbc1b41e8065a97c9c3d344b21fc81d27723af8e374bc595da26ea242dccb6ae497be26eea57e563ed517e90011010001889f0418010200090502533a52bc021b0c000a0910a42704b92866382afa1403ff70284c2de8a043ff51d8d29772602fa98009b7861c540535f874f2c230af8caf5638151a636b21f8255003997ccd29747fdd06777bb24f9593bd7d98a3e887689bf902f999915fcc94625ae487e5d13e6616f89090ebc4fdc7eb5cad8943e4056995bb61c6af37f8043016876a958ec7ebf39c43d20d53b7f546cfa83e8d2604b88d04533b8283010400c0b529316dbdf58b4c54461e7e669dc11c09eb7f73819f178ccd4177b9182b91d138605fcf1e463262fabefa73f94a52b5e15d1904635541c7ea540f07050ce0fb51b73e6f88644cec86e91107c957a114f69554548a85295d2b70bd0b203992f76eb5d493d86d9eabcaa7ef3fc7db7e458438db3fcdb0ca1cc97c638439a9170011010001889f0418010200090502533b8283021b0c000a0910a42704b92866382adc6d0400cfff6258485a21675adb7a811c3e19ebca18851533f75a7ba317950b9997fda8d1a4c8c76505c08c04b6c2cc31dc704d33da36a21273f2b388a1a706f7c3378b66d887197a525936ed9a69acb57fe7f718133da85ec742001c5d1864e9c6c8ea1b94f1c3759cebfd93b18606066c063a63be86085b7e37bdbc65f9a915bf084bb901a204533b85cd110400aed3d2c52af2b38b5b67904b0ef73d6dd7aef86adb770e2b153cd22489654dcc91730892087bb9856ae2d9f7ed1eb48f214243fe86bfe87b349ebd7c30e630e49c07b21fdabf78b7a95c8b7f969e97e3d33f2e074c63552ba64a2ded7badc05ce0ea2be6d53485f6900c7860c7aa76560376ce963d7271b9b54638a4028b573f00a0d8854bfcdb04986141568046202192263b9b67350400aaa1049dbc7943141ef590a70dcb028d730371d92ea4863de715f7f0f16d168bd3dc266c2450457d46dcbbf0b071547e5fbee7700a820c3750b236335d8d5848adb3c0da010e998908dfd93d961480084f3aea20b247034f8988eccb5546efaa35a92d0451df3aaf1aee5aa36a4c4d462c760ecd9cebcabfbe1412b1f21450f203fd126687cd486496e971a87fd9e1a8a765fe654baa219a6871ab97768596ab05c26c1aeea8f1a2c72395a58dbc12ef9640d2b95784e974a4d2d5a9b17c25fedacfe551bda52602de8f6d2e48443f5dd1a2a2a8e6a5e70ecdb88cd6e766ad9745c7ee91d78cc55c3d06536b49c3fee6c3d0b6ff0fb2bf13a314f57c953b8f4d93bf88e70418010200090502533b85cd021b0200520910a42704b92866382a47200419110200060502533b85cd000a091042ce2c64bc0ba99214b2009e26b26852c8b13b10c35768e40e78fbbb48bd084100a0c79d9ea0844fa5853dd3c85ff3ecae6f2c9dd6c557aa04008bbbc964cd65b9b8299d4ebf31f41cc7264b8cf33a00e82c5af022331fac79efc9563a822497ba012953cefe2629f1242fcdcb911dbb2315985bab060bfd58261ace3c654bdbbe2e8ed27a46e836490145c86dc7bae15c011f7e1ffc33730109b9338cd9f483e7cef3d2f396aab5bd80efb6646d7e778270ee99d934d187dd98"
 const revokedKeyHex = "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"
--- a/vendor/golang.org/x/crypto/openpgp/packet/encrypted_key.go
+++ b/vendor/golang.org/x/crypto/openpgp/packet/encrypted_key.go
@ -42,12 +42,18 @@ func (e *EncryptedKey) parse(r io.Reader) (err error) {
 	switch e.Algo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
 		e.encryptedMPI1.bytes, e.encryptedMPI1.bitLength, err = readMPI(r)
+		if err != nil {
+			return
+		}
 	case PubKeyAlgoElGamal:
 		e.encryptedMPI1.bytes, e.encryptedMPI1.bitLength, err = readMPI(r)
 		if err != nil {
 			return
 		}
 		e.encryptedMPI2.bytes, e.encryptedMPI2.bitLength, err = readMPI(r)
+		if err != nil {
+			return
+		}
 	}
 	_, err = consumeAll(r)
 	return
@ -72,7 +78,8 @@ func (e *EncryptedKey) Decrypt(priv *PrivateKey, config *Config) error {
 	// padding oracle attacks.
 	switch priv.PubKeyAlgo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSAEncryptOnly:
-		b, err = rsa.DecryptPKCS1v15(config.Random(), priv.PrivateKey.(*rsa.PrivateKey), e.encryptedMPI1.bytes)
+		k := priv.PrivateKey.(*rsa.PrivateKey)
+		b, err = rsa.DecryptPKCS1v15(config.Random(), k, padToKeySize(&k.PublicKey, e.encryptedMPI1.bytes))
 	case PubKeyAlgoElGamal:
 		c1 := new(big.Int).SetBytes(e.encryptedMPI1.bytes)
 		c2 := new(big.Int).SetBytes(e.encryptedMPI2.bytes)
--- a/vendor/golang.org/x/crypto/openpgp/packet/encrypted_key_test.go
+++ b/vendor/golang.org/x/crypto/openpgp/packet/encrypted_key_test.go
@ -39,39 +39,44 @@ var encryptedKeyPriv = &PrivateKey{
 }

 func TestDecryptingEncryptedKey(t *testing.T) {
-	const encryptedKeyHex = "c18c032a67d68660df41c70104005789d0de26b6a50c985a02a13131ca829c413a35d0e6fa8d6842599252162808ac7439c72151c8c6183e76923fe3299301414d0c25a2f06a2257db3839e7df0ec964773f6e4c4ac7ff3b48c444237166dd46ba8ff443a5410dc670cb486672fdbe7c9dfafb75b4fea83af3a204fe2a7dfa86bd20122b4f3d2646cbeecb8f7be8"
+	for i, encryptedKeyHex := range []string{
+		"c18c032a67d68660df41c70104005789d0de26b6a50c985a02a13131ca829c413a35d0e6fa8d6842599252162808ac7439c72151c8c6183e76923fe3299301414d0c25a2f06a2257db3839e7df0ec964773f6e4c4ac7ff3b48c444237166dd46ba8ff443a5410dc670cb486672fdbe7c9dfafb75b4fea83af3a204fe2a7dfa86bd20122b4f3d2646cbeecb8f7be8",
+		// MPI can be shorter than the length of the key.
+		"c18b032a67d68660df41c70103f8e520c52ae9807183c669ce26e772e482dc5d8cf60e6f59316e145be14d2e5221ee69550db1d5618a8cb002a719f1f0b9345bde21536d410ec90ba86cac37748dec7933eb7f9873873b2d61d3321d1cd44535014f6df58f7bc0c7afb5edc38e1a974428997d2f747f9a173bea9ca53079b409517d332df62d805564cffc9be6",
+	} {
 		const expectedKeyHex = "d930363f7e0308c333b9618617ea728963d8df993665ae7be1092d4926fd864b"

 		p, err := Read(readerFromHex(encryptedKeyHex))
 		if err != nil {
-		t.Errorf("error from Read: %s", err)
+			t.Errorf("#%d: error from Read: %s", i, err)
 			return
 		}
 		ek, ok := p.(*EncryptedKey)
 		if !ok {
-		t.Errorf("didn't parse an EncryptedKey, got %#v", p)
+			t.Errorf("#%d: didn't parse an EncryptedKey, got %#v", i, p)
 			return
 		}

 		if ek.KeyId != 0x2a67d68660df41c7 || ek.Algo != PubKeyAlgoRSA {
-		t.Errorf("unexpected EncryptedKey contents: %#v", ek)
+			t.Errorf("#%d: unexpected EncryptedKey contents: %#v", i, ek)
 			return
 		}

 		err = ek.Decrypt(encryptedKeyPriv, nil)
 		if err != nil {
-		t.Errorf("error from Decrypt: %s", err)
+			t.Errorf("#%d: error from Decrypt: %s", i, err)
 			return
 		}

 		if ek.CipherFunc != CipherAES256 {
-		t.Errorf("unexpected EncryptedKey contents: %#v", ek)
+			t.Errorf("#%d: unexpected EncryptedKey contents: %#v", i, ek)
 			return
 		}

 		keyHex := fmt.Sprintf("%x", ek.Key)
 		if keyHex != expectedKeyHex {
-		t.Errorf("bad key, got %s want %x", keyHex, expectedKeyHex)
+			t.Errorf("#%d: bad key, got %s want %s", i, keyHex, expectedKeyHex)
+		}
 	}
 }

@ -121,7 +126,7 @@ func TestEncryptingEncryptedKey(t *testing.T) {

 	keyHex := fmt.Sprintf("%x", ek.Key)
 	if keyHex != expectedKeyHex {
-		t.Errorf("bad key, got %s want %x", keyHex, expectedKeyHex)
+		t.Errorf("bad key, got %s want %s", keyHex, expectedKeyHex)
 	}
 }

--- a/vendor/golang.org/x/crypto/openpgp/packet/packet.go
+++ b/vendor/golang.org/x/crypto/openpgp/packet/packet.go
@ -11,10 +11,12 @@ import (
 	"crypto/aes"
 	"crypto/cipher"
 	"crypto/des"
-	"golang.org/x/crypto/cast5"
-	"golang.org/x/crypto/openpgp/errors"
+	"crypto/rsa"
 	"io"
 	"math/big"
+
+	"golang.org/x/crypto/cast5"
+	"golang.org/x/crypto/openpgp/errors"
 )

 // readFull is the same as io.ReadFull except that reading zero bytes returns
@ -500,19 +502,17 @@ func readMPI(r io.Reader) (mpi []byte, bitLength uint16, err error) {
 	numBytes := (int(bitLength) + 7) / 8
 	mpi = make([]byte, numBytes)
 	_, err = readFull(r, mpi)
-	return
-}
-
-// mpiLength returns the length of the given *big.Int when serialized as an
-// MPI.
-func mpiLength(n *big.Int) (mpiLengthInBytes int) {
-	mpiLengthInBytes = 2 /* MPI length */
-	mpiLengthInBytes += (n.BitLen() + 7) / 8
+	// According to RFC 4880 3.2. we should check that the MPI has no leading
+	// zeroes (at least when not an encrypted MPI?), but this implementation
+	// does generate leading zeroes, so we keep accepting them.
 	return
 }

 // writeMPI serializes a big integer to w.
 func writeMPI(w io.Writer, bitLength uint16, mpiBytes []byte) (err error) {
+	// Note that we can produce leading zeroes, in violation of RFC 4880 3.2.
+	// Implementations seem to be tolerant of them, and stripping them would
+	// make it complex to guarantee matching re-serialization.
 	_, err = w.Write([]byte{byte(bitLength >> 8), byte(bitLength)})
 	if err == nil {
 		_, err = w.Write(mpiBytes)
@ -525,6 +525,18 @@ func writeBig(w io.Writer, i *big.Int) error {
 	return writeMPI(w, uint16(i.BitLen()), i.Bytes())
 }

+// padToKeySize left-pads a MPI with zeroes to match the length of the
+// specified RSA public.
+func padToKeySize(pub *rsa.PublicKey, b []byte) []byte {
+	k := (pub.N.BitLen() + 7) / 8
+	if len(b) >= k {
+		return b
+	}
+	bb := make([]byte, k)
+	copy(bb[len(bb)-len(b):], b)
+	return bb
+}
+
 // CompressionAlgo Represents the different compression algorithms
 // supported by OpenPGP (except for BZIP2, which is not currently
 // supported). See Section 9.3 of RFC 4880.
--- a/vendor/golang.org/x/crypto/openpgp/packet/public_key.go
+++ b/vendor/golang.org/x/crypto/openpgp/packet/public_key.go
@ -244,7 +244,12 @@ func NewECDSAPublicKey(creationTime time.Time, pub *ecdsa.PublicKey) *PublicKey
 	}

 	pk.ec.p.bytes = elliptic.Marshal(pub.Curve, pub.X, pub.Y)
-	pk.ec.p.bitLength = uint16(8 * len(pk.ec.p.bytes))
+
+	// The bit length is 3 (for the 0x04 specifying an uncompressed key)
+	// plus two field elements (for x and y), which are rounded up to the
+	// nearest byte. See https://tools.ietf.org/html/rfc6637#section-6
+	fieldBytes := (pub.Curve.Params().BitSize + 7) & ^7
+	pk.ec.p.bitLength = uint16(3 + fieldBytes + fieldBytes)

 	pk.setFingerPrintAndKeyId()
 	return pk
@ -515,7 +520,7 @@ func (pk *PublicKey) VerifySignature(signed hash.Hash, sig *Signature) (err erro
 	switch pk.PubKeyAlgo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
 		rsaPublicKey, _ := pk.PublicKey.(*rsa.PublicKey)
-		err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes)
+		err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, padToKeySize(rsaPublicKey, sig.RSASignature.bytes))
 		if err != nil {
 			return errors.SignatureError("RSA verification failure")
 		}
@ -566,7 +571,7 @@ func (pk *PublicKey) VerifySignatureV3(signed hash.Hash, sig *SignatureV3) (err
 	switch pk.PubKeyAlgo {
 	case PubKeyAlgoRSA, PubKeyAlgoRSASignOnly:
 		rsaPublicKey := pk.PublicKey.(*rsa.PublicKey)
-		if err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, sig.RSASignature.bytes); err != nil {
+		if err = rsa.VerifyPKCS1v15(rsaPublicKey, sig.Hash, hashBytes, padToKeySize(rsaPublicKey, sig.RSASignature.bytes)); err != nil {
 			return errors.SignatureError("RSA verification failure")
 		}
 		return
--- a/vendor/golang.org/x/crypto/openpgp/packet/public_key_test.go
+++ b/vendor/golang.org/x/crypto/openpgp/packet/public_key_test.go
@ -6,7 +6,10 @@ package packet

 import (
 	"bytes"
+	"crypto/ecdsa"
+	"crypto/elliptic"
 	"encoding/hex"
+	"math/big"
 	"testing"
 	"time"
 )
@ -186,6 +189,29 @@ func TestEcc384Serialize(t *testing.T) {
 	}
 }

+func TestP256KeyID(t *testing.T) {
+	// Confirm that key IDs are correctly calculated for ECC keys.
+	ecdsaPub := &ecdsa.PublicKey{
+		Curve: elliptic.P256(),
+		X:     fromHex("81fbbc20eea9e8d1c3ceabb0a8185925b113d1ac42cd5c78403bd83da19235c6"),
+		Y:     fromHex("5ed6db13d91db34507d0129bf88981878d29adbf8fcd1720afdb767bb3fcaaff"),
+	}
+	pub := NewECDSAPublicKey(time.Unix(1297309478, 0), ecdsaPub)
+
+	const want = uint64(0xd01055fbcadd268e)
+	if pub.KeyId != want {
+		t.Errorf("want key ID: %x, got %x", want, pub.KeyId)
+	}
+}
+
+func fromHex(hex string) *big.Int {
+	n, ok := new(big.Int).SetString(hex, 16)
+	if !ok {
+		panic("bad hex number: " + hex)
+	}
+	return n
+}
+
 const rsaFingerprintHex = "5fb74b1d03b1e3cb31bc2f8aa34d7e18c20c31bb"

 const rsaPkDataHex = "988d044d3c5c10010400b1d13382944bd5aba23a4312968b5095d14f947f600eb478e14a6fcb16b0e0cac764884909c020bc495cfcc39a935387c661507bdb236a0612fb582cac3af9b29cc2c8c70090616c41b662f4da4c1201e195472eb7f4ae1ccbcbf9940fe21d985e379a5563dde5b9a23d35f1cfaa5790da3b79db26f23695107bfaca8e7b5bcd0011010001"
--- a/vendor/golang.org/x/crypto/ripemd160/ripemd160_test.go
+++ b/vendor/golang.org/x/crypto/ripemd160/ripemd160_test.go
@ -50,15 +50,23 @@ func TestVectors(t *testing.T) {
 	}
 }

-func TestMillionA(t *testing.T) {
+func millionA() string {
 	md := New()
 	for i := 0; i < 100000; i++ {
 		io.WriteString(md, "aaaaaaaaaa")
 	}
-	out := "52783243c1697bdbe16d37f97f68f08325dc1528"
-	s := fmt.Sprintf("%x", md.Sum(nil))
-	if s != out {
+	return fmt.Sprintf("%x", md.Sum(nil))
+}
+
+func TestMillionA(t *testing.T) {
+	const out = "52783243c1697bdbe16d37f97f68f08325dc1528"
+	if s := millionA(); s != out {
 		t.Fatalf("RIPEMD-160 (1 million 'a') = %s, expected %s", s, out)
 	}
-	md.Reset()
+}
+
+func BenchmarkMillionA(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		millionA()
+	}
 }
--- a/vendor/golang.org/x/crypto/ripemd160/ripemd160block.go
+++ b/vendor/golang.org/x/crypto/ripemd160/ripemd160block.go
@ -8,6 +8,10 @@

 package ripemd160

+import (
+	"math/bits"
+)
+
 // work buffer indices and roll amounts for one line
 var _n = [80]uint{
 	0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
@ -59,16 +63,16 @@ func _Block(md *digest, p []byte) int {
 		i := 0
 		for i < 16 {
 			alpha = a + (b ^ c ^ d) + x[_n[i]]
-			s := _r[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + e
-			beta = c<<10 | c>>22
+			s := int(_r[i])
+			alpha = bits.RotateLeft32(alpha, s) + e
+			beta = bits.RotateLeft32(c, 10)
 			a, b, c, d, e = e, alpha, b, beta, d

 			// parallel line
 			alpha = aa + (bb ^ (cc | ^dd)) + x[n_[i]] + 0x50a28be6
-			s = r_[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + ee
-			beta = cc<<10 | cc>>22
+			s = int(r_[i])
+			alpha = bits.RotateLeft32(alpha, s) + ee
+			beta = bits.RotateLeft32(cc, 10)
 			aa, bb, cc, dd, ee = ee, alpha, bb, beta, dd

 			i++
@ -77,16 +81,16 @@ func _Block(md *digest, p []byte) int {
 		// round 2
 		for i < 32 {
 			alpha = a + (b&c | ^b&d) + x[_n[i]] + 0x5a827999
-			s := _r[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + e
-			beta = c<<10 | c>>22
+			s := int(_r[i])
+			alpha = bits.RotateLeft32(alpha, s) + e
+			beta = bits.RotateLeft32(c, 10)
 			a, b, c, d, e = e, alpha, b, beta, d

 			// parallel line
 			alpha = aa + (bb&dd | cc&^dd) + x[n_[i]] + 0x5c4dd124
-			s = r_[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + ee
-			beta = cc<<10 | cc>>22
+			s = int(r_[i])
+			alpha = bits.RotateLeft32(alpha, s) + ee
+			beta = bits.RotateLeft32(cc, 10)
 			aa, bb, cc, dd, ee = ee, alpha, bb, beta, dd

 			i++
@ -95,16 +99,16 @@ func _Block(md *digest, p []byte) int {
 		// round 3
 		for i < 48 {
 			alpha = a + (b | ^c ^ d) + x[_n[i]] + 0x6ed9eba1
-			s := _r[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + e
-			beta = c<<10 | c>>22
+			s := int(_r[i])
+			alpha = bits.RotateLeft32(alpha, s) + e
+			beta = bits.RotateLeft32(c, 10)
 			a, b, c, d, e = e, alpha, b, beta, d

 			// parallel line
 			alpha = aa + (bb | ^cc ^ dd) + x[n_[i]] + 0x6d703ef3
-			s = r_[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + ee
-			beta = cc<<10 | cc>>22
+			s = int(r_[i])
+			alpha = bits.RotateLeft32(alpha, s) + ee
+			beta = bits.RotateLeft32(cc, 10)
 			aa, bb, cc, dd, ee = ee, alpha, bb, beta, dd

 			i++
@ -113,16 +117,16 @@ func _Block(md *digest, p []byte) int {
 		// round 4
 		for i < 64 {
 			alpha = a + (b&d | c&^d) + x[_n[i]] + 0x8f1bbcdc
-			s := _r[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + e
-			beta = c<<10 | c>>22
+			s := int(_r[i])
+			alpha = bits.RotateLeft32(alpha, s) + e
+			beta = bits.RotateLeft32(c, 10)
 			a, b, c, d, e = e, alpha, b, beta, d

 			// parallel line
 			alpha = aa + (bb&cc | ^bb&dd) + x[n_[i]] + 0x7a6d76e9
-			s = r_[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + ee
-			beta = cc<<10 | cc>>22
+			s = int(r_[i])
+			alpha = bits.RotateLeft32(alpha, s) + ee
+			beta = bits.RotateLeft32(cc, 10)
 			aa, bb, cc, dd, ee = ee, alpha, bb, beta, dd

 			i++
@ -131,16 +135,16 @@ func _Block(md *digest, p []byte) int {
 		// round 5
 		for i < 80 {
 			alpha = a + (b ^ (c | ^d)) + x[_n[i]] + 0xa953fd4e
-			s := _r[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + e
-			beta = c<<10 | c>>22
+			s := int(_r[i])
+			alpha = bits.RotateLeft32(alpha, s) + e
+			beta = bits.RotateLeft32(c, 10)
 			a, b, c, d, e = e, alpha, b, beta, d

 			// parallel line
 			alpha = aa + (bb ^ cc ^ dd) + x[n_[i]]
-			s = r_[i]
-			alpha = (alpha<<s | alpha>>(32-s)) + ee
-			beta = cc<<10 | cc>>22
+			s = int(r_[i])
+			alpha = bits.RotateLeft32(alpha, s) + ee
+			beta = bits.RotateLeft32(cc, 10)
 			aa, bb, cc, dd, ee = ee, alpha, bb, beta, dd

 			i++
--- a/vendor/golang.org/x/crypto/sha3/shake.go
+++ b/vendor/golang.org/x/crypto/sha3/shake.go
@ -40,7 +40,7 @@ func (d *state) Clone() ShakeHash {
 // least 32 bytes of its output are used.
 func NewShake128() ShakeHash { return &state{rate: 168, dsbyte: 0x1f} }

-// NewShake256 creates a new SHAKE128 variable-output-length ShakeHash.
+// NewShake256 creates a new SHAKE256 variable-output-length ShakeHash.
 // Its generic security strength is 256 bits against all attacks if
 // at least 64 bytes of its output are used.
 func NewShake256() ShakeHash { return &state{rate: 136, dsbyte: 0x1f} }
--- 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
--- 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
+		}
 		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
 			}
-			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(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
 		}
 	}
--- a/vendor/golang.org/x/crypto/ssh/client_auth_test.go
+++ b/vendor/golang.org/x/crypto/ssh/client_auth_test.go
@ -614,8 +614,8 @@ func TestClientAuthErrorList(t *testing.T) {
 	for i, e := range authErrs.Errors {
 		switch i {
 		case 0:
-			if e.Error() != "no auth passed yet" {
-				t.Fatalf("errors: got %v, want no auth passed yet", e.Error())
+			if e != ErrNoAuth {
+				t.Fatalf("errors: got error %v, want ErrNoAuth", e)
 			}
 		case 1:
 			if e != publicKeyErr {
--- 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
--- a/vendor/golang.org/x/crypto/ssh/keys_test.go
+++ b/vendor/golang.org/x/crypto/ssh/keys_test.go
@ -234,7 +234,7 @@ func TestMarshalParsePublicKey(t *testing.T) {
 	}
 }

-type authResult struct {
+type testAuthResult struct {
 	pubKey   PublicKey
 	options  []string
 	comments string
@ -242,11 +242,11 @@ type authResult struct {
 	ok       bool
 }

-func testAuthorizedKeys(t *testing.T, authKeys []byte, expected []authResult) {
+func testAuthorizedKeys(t *testing.T, authKeys []byte, expected []testAuthResult) {
 	rest := authKeys
-	var values []authResult
+	var values []testAuthResult
 	for len(rest) > 0 {
-		var r authResult
+		var r testAuthResult
 		var err error
 		r.pubKey, r.comments, r.options, rest, err = ParseAuthorizedKey(rest)
 		r.ok = (err == nil)
@ -264,7 +264,7 @@ func TestAuthorizedKeyBasic(t *testing.T) {
 	pub, pubSerialized := getTestKey()
 	line := "ssh-rsa " + pubSerialized + " user@host"
 	testAuthorizedKeys(t, []byte(line),
-		[]authResult{
+		[]testAuthResult{
 			{pub, nil, "user@host", "", true},
 		})
 }
@ -286,7 +286,7 @@ func TestAuth(t *testing.T) {
 		authOptions := strings.Join(authWithOptions, eol)
 		rest2 := strings.Join(authWithOptions[3:], eol)
 		rest3 := strings.Join(authWithOptions[6:], eol)
-		testAuthorizedKeys(t, []byte(authOptions), []authResult{
+		testAuthorizedKeys(t, []byte(authOptions), []testAuthResult{
 			{pub, []string{`env="HOME=/home/root"`, "no-port-forwarding"}, "user@host", rest2, true},
 			{pub, []string{`env="HOME=/home/root2"`}, "user2@host2", rest3, true},
 			{nil, nil, "", "", false},
@ -297,7 +297,7 @@ func TestAuth(t *testing.T) {
 func TestAuthWithQuotedSpaceInEnv(t *testing.T) {
 	pub, pubSerialized := getTestKey()
 	authWithQuotedSpaceInEnv := []byte(`env="HOME=/home/root dir",no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host`)
-	testAuthorizedKeys(t, []byte(authWithQuotedSpaceInEnv), []authResult{
+	testAuthorizedKeys(t, []byte(authWithQuotedSpaceInEnv), []testAuthResult{
 		{pub, []string{`env="HOME=/home/root dir"`, "no-port-forwarding"}, "user@host", "", true},
 	})
 }
@ -305,7 +305,7 @@ func TestAuthWithQuotedSpaceInEnv(t *testing.T) {
 func TestAuthWithQuotedCommaInEnv(t *testing.T) {
 	pub, pubSerialized := getTestKey()
 	authWithQuotedCommaInEnv := []byte(`env="HOME=/home/root,dir",no-port-forwarding ssh-rsa ` + pubSerialized + `   user@host`)
-	testAuthorizedKeys(t, []byte(authWithQuotedCommaInEnv), []authResult{
+	testAuthorizedKeys(t, []byte(authWithQuotedCommaInEnv), []testAuthResult{
 		{pub, []string{`env="HOME=/home/root,dir"`, "no-port-forwarding"}, "user@host", "", true},
 	})
 }
@ -314,11 +314,11 @@ func TestAuthWithQuotedQuoteInEnv(t *testing.T) {
 	pub, pubSerialized := getTestKey()
 	authWithQuotedQuoteInEnv := []byte(`env="HOME=/home/\"root dir",no-port-forwarding` + "\t" + `ssh-rsa` + "\t" + pubSerialized + `   user@host`)
 	authWithDoubleQuotedQuote := []byte(`no-port-forwarding,env="HOME=/home/ \"root dir\"" ssh-rsa ` + pubSerialized + "\t" + `user@host`)
-	testAuthorizedKeys(t, []byte(authWithQuotedQuoteInEnv), []authResult{
+	testAuthorizedKeys(t, []byte(authWithQuotedQuoteInEnv), []testAuthResult{
 		{pub, []string{`env="HOME=/home/\"root dir"`, "no-port-forwarding"}, "user@host", "", true},
 	})

-	testAuthorizedKeys(t, []byte(authWithDoubleQuotedQuote), []authResult{
+	testAuthorizedKeys(t, []byte(authWithDoubleQuotedQuote), []testAuthResult{
 		{pub, []string{"no-port-forwarding", `env="HOME=/home/ \"root dir\""`}, "user@host", "", true},
 	})
 }
@ -327,7 +327,7 @@ func TestAuthWithInvalidSpace(t *testing.T) {
 	_, pubSerialized := getTestKey()
 	authWithInvalidSpace := []byte(`env="HOME=/home/root dir", no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host
 #more to follow but still no valid keys`)
-	testAuthorizedKeys(t, []byte(authWithInvalidSpace), []authResult{
+	testAuthorizedKeys(t, []byte(authWithInvalidSpace), []testAuthResult{
 		{nil, nil, "", "", false},
 	})
 }
@ -337,7 +337,7 @@ func TestAuthWithMissingQuote(t *testing.T) {
 	authWithMissingQuote := []byte(`env="HOME=/home/root,no-port-forwarding ssh-rsa ` + pubSerialized + ` user@host
 env="HOME=/home/root",shared-control ssh-rsa ` + pubSerialized + ` user@host`)

-	testAuthorizedKeys(t, []byte(authWithMissingQuote), []authResult{
+	testAuthorizedKeys(t, []byte(authWithMissingQuote), []testAuthResult{
 		{pub, []string{`env="HOME=/home/root"`, `shared-control`}, "user@host", "", true},
 	})
 }
--- a/vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go
+++ b/vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go
@ -414,7 +414,7 @@ func (db *hostKeyDB) Read(r io.Reader, filename string) error {

 // 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.
+// ssh.ClientConfig.HostKeyCallback.
 func New(files ...string) (ssh.HostKeyCallback, error) {
 	db := newHostKeyDB()
 	for _, fn := range files {
--- 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()
@ -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":
--- a/vendor/golang.org/x/crypto/ssh/terminal/util.go
+++ b/vendor/golang.org/x/crypto/ssh/terminal/util.go
@ -108,9 +108,7 @@ func ReadPassword(fd int) ([]byte, error) {
 		return nil, err
 	}

-	defer func() {
-		unix.IoctlSetTermios(fd, ioctlWriteTermios, termios)
-	}()
+	defer unix.IoctlSetTermios(fd, ioctlWriteTermios, termios)

 	return readPasswordLine(passwordReader(fd))
 }
--- a/vendor/golang.org/x/crypto/ssh/terminal/util_solaris.go
+++ b/vendor/golang.org/x/crypto/ssh/terminal/util_solaris.go
@ -14,7 +14,7 @@ import (

 // State contains the state of a terminal.
 type State struct {
-	state *unix.Termios
+	termios unix.Termios
 }

 // IsTerminal returns true if the given file descriptor is a terminal.
@ -75,47 +75,43 @@ func ReadPassword(fd int) ([]byte, error) {
 // restored.
 // see http://cr.illumos.org/~webrev/andy_js/1060/
 func MakeRaw(fd int) (*State, error) {
-	oldTermiosPtr, err := unix.IoctlGetTermios(fd, unix.TCGETS)
+	termios, err := unix.IoctlGetTermios(fd, unix.TCGETS)
 	if err != nil {
 		return nil, err
 	}
-	oldTermios := *oldTermiosPtr

-	newTermios := oldTermios
-	newTermios.Iflag &^= syscall.IGNBRK | syscall.BRKINT | syscall.PARMRK | syscall.ISTRIP | syscall.INLCR | syscall.IGNCR | syscall.ICRNL | syscall.IXON
-	newTermios.Oflag &^= syscall.OPOST
-	newTermios.Lflag &^= syscall.ECHO | syscall.ECHONL | syscall.ICANON | syscall.ISIG | syscall.IEXTEN
-	newTermios.Cflag &^= syscall.CSIZE | syscall.PARENB
-	newTermios.Cflag |= syscall.CS8
-	newTermios.Cc[unix.VMIN] = 1
-	newTermios.Cc[unix.VTIME] = 0
+	oldState := State{termios: *termios}

-	if err := unix.IoctlSetTermios(fd, unix.TCSETS, &newTermios); err != nil {
+	termios.Iflag &^= unix.IGNBRK | unix.BRKINT | unix.PARMRK | unix.ISTRIP | unix.INLCR | unix.IGNCR | unix.ICRNL | unix.IXON
+	termios.Oflag &^= unix.OPOST
+	termios.Lflag &^= unix.ECHO | unix.ECHONL | unix.ICANON | unix.ISIG | unix.IEXTEN
+	termios.Cflag &^= unix.CSIZE | unix.PARENB
+	termios.Cflag |= unix.CS8
+	termios.Cc[unix.VMIN] = 1
+	termios.Cc[unix.VTIME] = 0
+
+	if err := unix.IoctlSetTermios(fd, unix.TCSETS, termios); err != nil {
 		return nil, err
 	}

-	return &State{
-		state: oldTermiosPtr,
-	}, nil
+	return &oldState, nil
 }

 // Restore restores the terminal connected to the given file descriptor to a
 // previous state.
 func Restore(fd int, oldState *State) error {
-	return unix.IoctlSetTermios(fd, unix.TCSETS, oldState.state)
+	return unix.IoctlSetTermios(fd, unix.TCSETS, &oldState.termios)
 }

 // GetState returns the current state of a terminal which may be useful to
 // restore the terminal after a signal.
 func GetState(fd int) (*State, error) {
-	oldTermiosPtr, err := unix.IoctlGetTermios(fd, unix.TCGETS)
+	termios, err := unix.IoctlGetTermios(fd, unix.TCGETS)
 	if err != nil {
 		return nil, err
 	}

-	return &State{
-		state: oldTermiosPtr,
-	}, nil
+	return &State{termios: *termios}, nil
 }

 // GetSize returns the dimensions of the given terminal.
--- a/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
+++ b/vendor/golang.org/x/crypto/ssh/terminal/util_windows.go
@ -89,9 +89,15 @@ func ReadPassword(fd int) ([]byte, error) {
 		return nil, err
 	}

-	defer func() {
-		windows.SetConsoleMode(windows.Handle(fd), old)
-	}()
+	defer 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)
 }
--- a/vendor/golang.org/x/crypto/ssh/test/multi_auth_test.go
+++ b/vendor/golang.org/x/crypto/ssh/test/multi_auth_test.go
@ -0,0 +1,144 @@
+// 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.
+
+// Tests for ssh client multi-auth
+//
+// These tests run a simple go ssh client against OpenSSH server
+// over unix domain sockets. The tests use multiple combinations
+// of password, keyboard-interactive and publickey authentication
+// methods.
+//
+// A wrapper library for making sshd PAM authentication use test
+// passwords is required in ./sshd_test_pw.so. If the library does
+// not exist these tests will be skipped. See compile instructions
+// (for linux) in file ./sshd_test_pw.c.
+
+// +build linux
+
+package test
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// test cases
+type multiAuthTestCase struct {
+	authMethods         []string
+	expectedPasswordCbs int
+	expectedKbdIntCbs   int
+}
+
+// test context
+type multiAuthTestCtx struct {
+	password       string
+	numPasswordCbs int
+	numKbdIntCbs   int
+}
+
+// create test context
+func newMultiAuthTestCtx(t *testing.T) *multiAuthTestCtx {
+	password, err := randomPassword()
+	if err != nil {
+		t.Fatalf("Failed to generate random test password: %s", err.Error())
+	}
+
+	return &multiAuthTestCtx{
+		password: password,
+	}
+}
+
+// password callback
+func (ctx *multiAuthTestCtx) passwordCb() (secret string, err error) {
+	ctx.numPasswordCbs++
+	return ctx.password, nil
+}
+
+// keyboard-interactive callback
+func (ctx *multiAuthTestCtx) kbdIntCb(user, instruction string, questions []string, echos []bool) (answers []string, err error) {
+	if len(questions) == 0 {
+		return nil, nil
+	}
+
+	ctx.numKbdIntCbs++
+	if len(questions) == 1 {
+		return []string{ctx.password}, nil
+	}
+
+	return nil, fmt.Errorf("unsupported keyboard-interactive flow")
+}
+
+// TestMultiAuth runs several subtests for different combinations of password, keyboard-interactive and publickey authentication methods
+func TestMultiAuth(t *testing.T) {
+	testCases := []multiAuthTestCase{
+		// Test password,publickey authentication, assert that password callback is called 1 time
+		multiAuthTestCase{
+			authMethods:         []string{"password", "publickey"},
+			expectedPasswordCbs: 1,
+		},
+		// Test keyboard-interactive,publickey authentication, assert that keyboard-interactive callback is called 1 time
+		multiAuthTestCase{
+			authMethods:       []string{"keyboard-interactive", "publickey"},
+			expectedKbdIntCbs: 1,
+		},
+		// Test publickey,password authentication, assert that password callback is called 1 time
+		multiAuthTestCase{
+			authMethods:         []string{"publickey", "password"},
+			expectedPasswordCbs: 1,
+		},
+		// Test publickey,keyboard-interactive authentication, assert that keyboard-interactive callback is called 1 time
+		multiAuthTestCase{
+			authMethods:       []string{"publickey", "keyboard-interactive"},
+			expectedKbdIntCbs: 1,
+		},
+		// Test password,password authentication, assert that password callback is called 2 times
+		multiAuthTestCase{
+			authMethods:         []string{"password", "password"},
+			expectedPasswordCbs: 2,
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(strings.Join(testCase.authMethods, ","), func(t *testing.T) {
+			ctx := newMultiAuthTestCtx(t)
+
+			server := newServerForConfig(t, "MultiAuth", map[string]string{"AuthMethods": strings.Join(testCase.authMethods, ",")})
+			defer server.Shutdown()
+
+			clientConfig := clientConfig()
+			server.setTestPassword(clientConfig.User, ctx.password)
+
+			publicKeyAuthMethod := clientConfig.Auth[0]
+			clientConfig.Auth = nil
+			for _, authMethod := range testCase.authMethods {
+				switch authMethod {
+				case "publickey":
+					clientConfig.Auth = append(clientConfig.Auth, publicKeyAuthMethod)
+				case "password":
+					clientConfig.Auth = append(clientConfig.Auth,
+						ssh.RetryableAuthMethod(ssh.PasswordCallback(ctx.passwordCb), 5))
+				case "keyboard-interactive":
+					clientConfig.Auth = append(clientConfig.Auth,
+						ssh.RetryableAuthMethod(ssh.KeyboardInteractive(ctx.kbdIntCb), 5))
+				default:
+					t.Fatalf("Unknown authentication method %s", authMethod)
+				}
+			}
+
+			conn := server.Dial(clientConfig)
+			defer conn.Close()
+
+			if ctx.numPasswordCbs != testCase.expectedPasswordCbs {
+				t.Fatalf("passwordCallback was called %d times, expected %d times", ctx.numPasswordCbs, testCase.expectedPasswordCbs)
+			}
+
+			if ctx.numKbdIntCbs != testCase.expectedKbdIntCbs {
+				t.Fatalf("keyboardInteractiveCallback was called %d times, expected %d times", ctx.numKbdIntCbs, testCase.expectedKbdIntCbs)
+			}
+		})
+	}
+}
--- a/vendor/golang.org/x/crypto/ssh/test/sshd_test_pw.c
+++ b/vendor/golang.org/x/crypto/ssh/test/sshd_test_pw.c
@ -0,0 +1,173 @@
+// 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.
+
+// sshd_test_pw.c
+// Wrapper to inject test password data for sshd PAM authentication
+//
+// This wrapper implements custom versions of getpwnam, getpwnam_r,
+// getspnam and getspnam_r. These functions first call their real
+// libc versions, then check if the requested user matches test user
+// specified in env variable TEST_USER and if so replace the password
+// with crypted() value of TEST_PASSWD env variable.
+//
+// Compile:
+// gcc -Wall -shared -o sshd_test_pw.so -fPIC sshd_test_pw.c
+//
+// Compile with debug:
+// gcc -DVERBOSE -Wall -shared -o sshd_test_pw.so -fPIC sshd_test_pw.c
+//
+// Run sshd:
+// LD_PRELOAD="sshd_test_pw.so" TEST_USER="..." TEST_PASSWD="..." sshd ...
+
+// +build ignore
+
+#define _GNU_SOURCE
+#include <string.h>
+#include <pwd.h>
+#include <shadow.h>
+#include <dlfcn.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#ifdef VERBOSE
+#define DEBUG(X...) fprintf(stderr, X)
+#else
+#define DEBUG(X...) while (0) { }
+#endif
+
+/* crypt() password */
+static char *
+pwhash(char *passwd) {
+  return strdup(crypt(passwd, "$6$"));
+}
+
+/* Pointers to real functions in libc */
+static struct passwd * (*real_getpwnam)(const char *) = NULL;
+static int (*real_getpwnam_r)(const char *, struct passwd *, char *, size_t, struct passwd **) = NULL;
+static struct spwd * (*real_getspnam)(const char *) = NULL;
+static int (*real_getspnam_r)(const char *, struct spwd *, char *, size_t, struct spwd **) = NULL;
+
+/* Cached test user and test password */
+static char *test_user = NULL;
+static char *test_passwd_hash = NULL;
+
+static void
+init(void) {
+  /* Fetch real libc function pointers */
+  real_getpwnam = dlsym(RTLD_NEXT, "getpwnam");
+  real_getpwnam_r = dlsym(RTLD_NEXT, "getpwnam_r");
+  real_getspnam = dlsym(RTLD_NEXT, "getspnam");
+  real_getspnam_r = dlsym(RTLD_NEXT, "getspnam_r");
+  
+  /* abort if env variables are not defined */
+  if (getenv("TEST_USER") == NULL || getenv("TEST_PASSWD") == NULL) {
+    fprintf(stderr, "env variables TEST_USER and TEST_PASSWD are missing\n");
+    abort();
+  }
+
+  /* Fetch test user and test password from env */
+  test_user = strdup(getenv("TEST_USER"));
+  test_passwd_hash = pwhash(getenv("TEST_PASSWD"));
+
+  DEBUG("sshd_test_pw init():\n");
+  DEBUG("\treal_getpwnam: %p\n", real_getpwnam);
+  DEBUG("\treal_getpwnam_r: %p\n", real_getpwnam_r);
+  DEBUG("\treal_getspnam: %p\n", real_getspnam);
+  DEBUG("\treal_getspnam_r: %p\n", real_getspnam_r);
+  DEBUG("\tTEST_USER: '%s'\n", test_user);
+  DEBUG("\tTEST_PASSWD: '%s'\n", getenv("TEST_PASSWD"));
+  DEBUG("\tTEST_PASSWD_HASH: '%s'\n", test_passwd_hash);
+}
+
+static int
+is_test_user(const char *name) {
+  if (test_user != NULL && strcmp(test_user, name) == 0)
+    return 1;
+  return 0;
+}
+
+/* getpwnam */
+
+struct passwd *
+getpwnam(const char *name) {
+  struct passwd *pw;
+
+  DEBUG("sshd_test_pw getpwnam(%s)\n", name);
+  
+  if (real_getpwnam == NULL)
+    init();
+  if ((pw = real_getpwnam(name)) == NULL)
+    return NULL;
+
+  if (is_test_user(name))
+    pw->pw_passwd = strdup(test_passwd_hash);
+      
+  return pw;
+}
+
+/* getpwnam_r */
+
+int
+getpwnam_r(const char *name,
+	   struct passwd *pwd,
+	   char *buf,
+	   size_t buflen,
+	   struct passwd **result) {
+  int r;
+
+  DEBUG("sshd_test_pw getpwnam_r(%s)\n", name);
+  
+  if (real_getpwnam_r == NULL)
+    init();
+  if ((r = real_getpwnam_r(name, pwd, buf, buflen, result)) != 0 || *result == NULL)
+    return r;
+
+  if (is_test_user(name))
+    pwd->pw_passwd = strdup(test_passwd_hash);
+  
+  return 0;
+}
+
+/* getspnam */
+
+struct spwd *
+getspnam(const char *name) {
+  struct spwd *sp;
+
+  DEBUG("sshd_test_pw getspnam(%s)\n", name);
+  
+  if (real_getspnam == NULL)
+    init();
+  if ((sp = real_getspnam(name)) == NULL)
+    return NULL;
+
+  if (is_test_user(name))
+    sp->sp_pwdp = strdup(test_passwd_hash);
+  
+  return sp;
+}
+
+/* getspnam_r */
+
+int
+getspnam_r(const char *name,
+	   struct spwd *spbuf,
+	   char *buf,
+	   size_t buflen,
+	   struct spwd **spbufp) {
+  int r;
+
+  DEBUG("sshd_test_pw getspnam_r(%s)\n", name);
+  
+  if (real_getspnam_r == NULL)
+    init();
+  if ((r = real_getspnam_r(name, spbuf, buf, buflen, spbufp)) != 0)
+    return r;
+
+  if (is_test_user(name))
+    spbuf->sp_pwdp = strdup(test_passwd_hash);
+  
+  return r;
+}
--- a/vendor/golang.org/x/crypto/ssh/test/test_unix_test.go
+++ b/vendor/golang.org/x/crypto/ssh/test/test_unix_test.go
@ -10,6 +10,8 @@ package test

 import (
 	"bytes"
+	"crypto/rand"
+	"encoding/base64"
 	"fmt"
 	"io/ioutil"
 	"log"
@ -25,7 +27,8 @@ import (
 	"golang.org/x/crypto/ssh/testdata"
 )

-const sshdConfig = `
+const (
+	defaultSshdConfig = `
 Protocol 2
 Banner {{.Dir}}/banner
 HostKey {{.Dir}}/id_rsa
@ -50,8 +53,17 @@ RhostsRSAAuthentication no
 HostbasedAuthentication no
 PubkeyAcceptedKeyTypes=*
 `
+	multiAuthSshdConfigTail = `
+UsePAM yes
+PasswordAuthentication yes
+ChallengeResponseAuthentication yes
+AuthenticationMethods {{.AuthMethods}}
+`
+)

-var configTmpl = template.Must(template.New("").Parse(sshdConfig))
+var configTmpl = map[string]*template.Template{
+	"default":   template.Must(template.New("").Parse(defaultSshdConfig)),
+	"MultiAuth": template.Must(template.New("").Parse(defaultSshdConfig + multiAuthSshdConfigTail))}

 type server struct {
 	t          *testing.T
@ -60,6 +72,10 @@ type server struct {
 	cmd        *exec.Cmd
 	output     bytes.Buffer // holds stderr from sshd process

+	testUser     string // test username for sshd
+	testPasswd   string // test password for sshd
+	sshdTestPwSo string // dynamic library to inject a custom password into sshd
+
 	// Client half of the network connection.
 	clientConn net.Conn
 }
@ -186,6 +202,20 @@ func (s *server) TryDialWithAddr(config *ssh.ClientConfig, addr string) (*ssh.Cl
 	s.cmd.Stdin = f
 	s.cmd.Stdout = f
 	s.cmd.Stderr = &s.output
+
+	if s.sshdTestPwSo != "" {
+		if s.testUser == "" {
+			s.t.Fatal("user missing from sshd_test_pw.so config")
+		}
+		if s.testPasswd == "" {
+			s.t.Fatal("password missing from sshd_test_pw.so config")
+		}
+		s.cmd.Env = append(os.Environ(),
+			fmt.Sprintf("LD_PRELOAD=%s", s.sshdTestPwSo),
+			fmt.Sprintf("TEST_USER=%s", s.testUser),
+			fmt.Sprintf("TEST_PASSWD=%s", s.testPasswd))
+	}
+
 	if err := s.cmd.Start(); err != nil {
 		s.t.Fail()
 		s.Shutdown()
@ -236,8 +266,39 @@ func writeFile(path string, contents []byte) {
 	}
 }

+// generate random password
+func randomPassword() (string, error) {
+	b := make([]byte, 12)
+	_, err := rand.Read(b)
+	if err != nil {
+		return "", err
+	}
+	return base64.RawURLEncoding.EncodeToString(b), nil
+}
+
+// setTestPassword is used for setting user and password data for sshd_test_pw.so
+// This function also checks that ./sshd_test_pw.so exists and if not calls s.t.Skip()
+func (s *server) setTestPassword(user, passwd string) error {
+	wd, _ := os.Getwd()
+	wrapper := filepath.Join(wd, "sshd_test_pw.so")
+	if _, err := os.Stat(wrapper); err != nil {
+		s.t.Skip(fmt.Errorf("sshd_test_pw.so is not available"))
+		return err
+	}
+
+	s.sshdTestPwSo = wrapper
+	s.testUser = user
+	s.testPasswd = passwd
+	return nil
+}
+
 // newServer returns a new mock ssh server.
 func newServer(t *testing.T) *server {
+	return newServerForConfig(t, "default", map[string]string{})
+}
+
+// newServerForConfig returns a new mock ssh server.
+func newServerForConfig(t *testing.T, config string, configVars map[string]string) *server {
 	if testing.Short() {
 		t.Skip("skipping test due to -short")
 	}
@ -249,9 +310,11 @@ func newServer(t *testing.T) *server {
 	if err != nil {
 		t.Fatal(err)
 	}
-	err = configTmpl.Execute(f, map[string]string{
-		"Dir": dir,
-	})
+	if _, ok := configTmpl[config]; ok == false {
+		t.Fatal(fmt.Errorf("Invalid server config '%s'", config))
+	}
+	configVars["Dir"] = dir
+	err = configTmpl[config].Execute(f, configVars)
 	if err != nil {
 		t.Fatal(err)
 	}
--- a/vendor/golang.org/x/crypto/xtea/block.go
+++ b/vendor/golang.org/x/crypto/xtea/block.go
@ -50,7 +50,7 @@ func encryptBlock(c *Cipher, dst, src []byte) {
 	uint32ToBlock(v0, v1, dst)
 }

-// decryptBlock decrypt a single 8 byte block using XTEA.
+// decryptBlock decrypts a single 8 byte block using XTEA.
 func decryptBlock(c *Cipher, dst, src []byte) {
 	v0, v1 := blockToUint32(src)

--- a/vendor/golang.org/x/crypto/xtea/cipher.go
+++ b/vendor/golang.org/x/crypto/xtea/cipher.go
@ -14,8 +14,8 @@ import "strconv"
 const BlockSize = 8

 // A Cipher is an instance of an XTEA cipher using a particular key.
-// table contains a series of precalculated values that are used each round.
 type Cipher struct {
+	// table contains a series of precalculated values that are used each round.
 	table [64]uint32
 }

@ -54,7 +54,7 @@ func (c *Cipher) BlockSize() int { return BlockSize }
 // instead, use an encryption mode like CBC (see crypto/cipher/cbc.go).
 func (c *Cipher) Encrypt(dst, src []byte) { encryptBlock(c, dst, src) }

-// Decrypt decrypts the 8 byte buffer src using the key k and stores the result in dst.
+// Decrypt decrypts the 8 byte buffer src using the key and stores the result in dst.
 func (c *Cipher) Decrypt(dst, src []byte) { decryptBlock(c, dst, src) }

 // initCipher initializes the cipher context by creating a look up table