Add support for Let's Encrypt http-01 challenge

30 files changed, 1967 insertions, 276 deletions

diff --git a/vendor/golang.org/x/crypto/acme/autocert/autocert.go b/vendor/golang.org/x/crypto/acme/autocert/autocert.go
index 94edba9..453e722 100644
--- a/vendor/golang.org/x/crypto/acme/autocert/autocert.go
+++ b/vendor/golang.org/x/crypto/acme/autocert/autocert.go
@@ -24,7 +24,9 @@ import (
 	"fmt"
 	"io"
 	mathrand "math/rand"
+	"net"
 	"net/http"
+	"path"
 	"strconv"
 	"strings"
 	"sync"
@@ -80,8 +82,9 @@ func defaultHostPolicy(context.Context, string) error {
 }
 
 // Manager is a stateful certificate manager built on top of acme.Client.
-// It obtains and refreshes certificates automatically,
-// as well as providing them to a TLS server via tls.Config.
+// It obtains and refreshes certificates automatically using "tls-sni-01",
+// "tls-sni-02" and "http-01" challenge types, as well as providing them
+// to a TLS server via tls.Config.
 //
 // You must specify a cache implementation, such as DirCache,
 // to reuse obtained certificates across program restarts.
@@ -150,15 +153,26 @@ type Manager struct {
 	stateMu sync.Mutex
 	state   map[string]*certState // keyed by domain name
 
-	// tokenCert is keyed by token domain name, which matches server name
-	// of ClientHello. Keys always have ".acme.invalid" suffix.
-	tokenCertMu sync.RWMutex
-	tokenCert   map[string]*tls.Certificate
-
 	// renewal tracks the set of domains currently running renewal timers.
 	// It is keyed by domain name.
 	renewalMu sync.Mutex
 	renewal   map[string]*domainRenewal
+
+	// tokensMu guards the rest of the fields: tryHTTP01, certTokens and httpTokens.
+	tokensMu sync.RWMutex
+	// tryHTTP01 indicates whether the Manager should try "http-01" challenge type
+	// during the authorization flow.
+	tryHTTP01 bool
+	// httpTokens contains response body values for http-01 challenges
+	// and is keyed by the URL path at which a challenge response is expected
+	// to be provisioned.
+	// The entries are stored for the duration of the authorization flow.
+	httpTokens map[string][]byte
+	// certTokens contains temporary certificates for tls-sni challenges
+	// and is keyed by token domain name, which matches server name of ClientHello.
+	// Keys always have ".acme.invalid" suffix.
+	// The entries are stored for the duration of the authorization flow.
+	certTokens map[string]*tls.Certificate
 }
 
 // GetCertificate implements the tls.Config.GetCertificate hook.
@@ -185,14 +199,16 @@ func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate,
 		return nil, errors.New("acme/autocert: server name contains invalid character")
 	}
 
+	// In the worst-case scenario, the timeout needs to account for caching, host policy,
+	// domain ownership verification and certificate issuance.
 	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Minute)
 	defer cancel()
 
 	// check whether this is a token cert requested for TLS-SNI challenge
 	if strings.HasSuffix(name, ".acme.invalid") {
-		m.tokenCertMu.RLock()
-		defer m.tokenCertMu.RUnlock()
-		if cert := m.tokenCert[name]; cert != nil {
+		m.tokensMu.RLock()
+		defer m.tokensMu.RUnlock()
+		if cert := m.certTokens[name]; cert != nil {
 			return cert, nil
 		}
 		if cert, err := m.cacheGet(ctx, name); err == nil {
@@ -224,6 +240,68 @@ func (m *Manager) GetCertificate(hello *tls.ClientHelloInfo) (*tls.Certificate,
 	return cert, nil
 }
 
+// HTTPHandler configures the Manager to provision ACME "http-01" challenge responses.
+// It returns an http.Handler that responds to the challenges and must be
+// running on port 80. If it receives a request that is not an ACME challenge,
+// it delegates the request to the optional fallback handler.
+//
+// If fallback is nil, the returned handler redirects all GET and HEAD requests
+// to the default TLS port 443 with 302 Found status code, preserving the original
+// request path and query. It responds with 400 Bad Request to all other HTTP methods.
+// The fallback is not protected by the optional HostPolicy.
+//
+// Because the fallback handler is run with unencrypted port 80 requests,
+// the fallback should not serve TLS-only requests.
+//
+// If HTTPHandler is never called, the Manager will only use TLS SNI
+// challenges for domain verification.
+func (m *Manager) HTTPHandler(fallback http.Handler) http.Handler {
+	m.tokensMu.Lock()
+	defer m.tokensMu.Unlock()
+	m.tryHTTP01 = true
+
+	if fallback == nil {
+		fallback = http.HandlerFunc(handleHTTPRedirect)
+	}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if !strings.HasPrefix(r.URL.Path, "/.well-known/acme-challenge/") {
+			fallback.ServeHTTP(w, r)
+			return
+		}
+		// A reasonable context timeout for cache and host policy only,
+		// because we don't wait for a new certificate issuance here.
+		ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
+		defer cancel()
+		if err := m.hostPolicy()(ctx, r.Host); err != nil {
+			http.Error(w, err.Error(), http.StatusForbidden)
+			return
+		}
+		data, err := m.httpToken(ctx, r.URL.Path)
+		if err != nil {
+			http.Error(w, err.Error(), http.StatusNotFound)
+			return
+		}
+		w.Write(data)
+	})
+}
+
+func handleHTTPRedirect(w http.ResponseWriter, r *http.Request) {
+	if r.Method != "GET" && r.Method != "HEAD" {
+		http.Error(w, "Use HTTPS", http.StatusBadRequest)
+		return
+	}
+	target := "https://" + stripPort(r.Host) + r.URL.RequestURI()
+	http.Redirect(w, r, target, http.StatusFound)
+}
+
+func stripPort(hostport string) string {
+	host, _, err := net.SplitHostPort(hostport)
+	if err != nil {
+		return hostport
+	}
+	return net.JoinHostPort(host, "443")
+}
+
 // cert returns an existing certificate either from m.state or cache.
 // If a certificate is found in cache but not in m.state, the latter will be filled
 // with the cached value.
@@ -442,13 +520,14 @@ func (m *Manager) certState(domain string) (*certState, error) {
 // authorizedCert starts the domain ownership verification process and requests a new cert upon success.
 // The key argument is the certificate private key.
 func (m *Manager) authorizedCert(ctx context.Context, key crypto.Signer, domain string) (der [][]byte, leaf *x509.Certificate, err error) {
-	if err := m.verify(ctx, domain); err != nil {
-		return nil, nil, err
-	}
 	client, err := m.acmeClient(ctx)
 	if err != nil {
 		return nil, nil, err
 	}
+
+	if err := m.verify(ctx, client, domain); err != nil {
+		return nil, nil, err
+	}
 	csr, err := certRequest(key, domain)
 	if err != nil {
 		return nil, nil, err
@@ -464,98 +543,171 @@ func (m *Manager) authorizedCert(ctx context.Context, key crypto.Signer, domain
 	return der, leaf, nil
 }
 
-// verify starts a new identifier (domain) authorization flow.
-// It prepares a challenge response and then blocks until the authorization
-// is marked as "completed" by the CA (either succeeded or failed).
-//
-// verify returns nil iff the verification was successful.
-func (m *Manager) verify(ctx context.Context, domain string) error {
-	client, err := m.acmeClient(ctx)
-	if err != nil {
-		return err
-	}
-
-	// start domain authorization and get the challenge
-	authz, err := client.Authorize(ctx, domain)
-	if err != nil {
-		return err
-	}
-	// maybe don't need to at all
-	if authz.Status == acme.StatusValid {
-		return nil
-	}
+// verify runs the identifier (domain) authorization flow
+// using each applicable ACME challenge type.
+func (m *Manager) verify(ctx context.Context, client *acme.Client, domain string) error {
+	// The list of challenge types we'll try to fulfill
+	// in this specific order.
+	challengeTypes := []string{"tls-sni-02", "tls-sni-01"}
+	m.tokensMu.RLock()
+	if m.tryHTTP01 {
+		challengeTypes = append(challengeTypes, "http-01")
+	}
+	m.tokensMu.RUnlock()
+
+	var nextTyp int // challengeType index of the next challenge type to try
+	for {
+		// Start domain authorization and get the challenge.
+		authz, err := client.Authorize(ctx, domain)
+		if err != nil {
+			return err
+		}
+		// No point in accepting challenges if the authorization status
+		// is in a final state.
+		switch authz.Status {
+		case acme.StatusValid:
+			return nil // already authorized
+		case acme.StatusInvalid:
+			return fmt.Errorf("acme/autocert: invalid authorization %q", authz.URI)
+		}
 
-	// pick a challenge: prefer tls-sni-02 over tls-sni-01
-	// TODO: consider authz.Combinations
-	var chal *acme.Challenge
-	for _, c := range authz.Challenges {
-		if c.Type == "tls-sni-02" {
-			chal = c
-			break
+		// Pick the next preferred challenge.
+		var chal *acme.Challenge
+		for chal == nil && nextTyp < len(challengeTypes) {
+			chal = pickChallenge(challengeTypes[nextTyp], authz.Challenges)
+			nextTyp++
 		}
-		if c.Type == "tls-sni-01" {
-			chal = c
+		if chal == nil {
+			return fmt.Errorf("acme/autocert: unable to authorize %q; tried %q", domain, challengeTypes)
+		}
+		cleanup, err := m.fulfill(ctx, client, chal)
+		if err != nil {
+			continue
+		}
+		defer cleanup()
+		if _, err := client.Accept(ctx, chal); err != nil {
+			continue
+		}
+
+		// A challenge is fulfilled and accepted: wait for the CA to validate.
+		if _, err := client.WaitAuthorization(ctx, authz.URI); err == nil {
+			return nil
 		}
 	}
-	if chal == nil {
-		return errors.New("acme/autocert: no supported challenge type found")
-	}
+}
 
-	// create a token cert for the challenge response
-	var (
-		cert tls.Certificate
-		name string
-	)
+// fulfill provisions a response to the challenge chal.
+// The cleanup is non-nil only if provisioning succeeded.
+func (m *Manager) fulfill(ctx context.Context, client *acme.Client, chal *acme.Challenge) (cleanup func(), err error) {
 	switch chal.Type {
 	case "tls-sni-01":
-		cert, name, err = client.TLSSNI01ChallengeCert(chal.Token)
+		cert, name, err := client.TLSSNI01ChallengeCert(chal.Token)
+		if err != nil {
+			return nil, err
+		}
+		m.putCertToken(ctx, name, &cert)
+		return func() { go m.deleteCertToken(name) }, nil
 	case "tls-sni-02":
-		cert, name, err = client.TLSSNI02ChallengeCert(chal.Token)
-	default:
-		err = fmt.Errorf("acme/autocert: unknown challenge type %q", chal.Type)
-	}
-	if err != nil {
-		return err
+		cert, name, err := client.TLSSNI02ChallengeCert(chal.Token)
+		if err != nil {
+			return nil, err
+		}
+		m.putCertToken(ctx, name, &cert)
+		return func() { go m.deleteCertToken(name) }, nil
+	case "http-01":
+		resp, err := client.HTTP01ChallengeResponse(chal.Token)
+		if err != nil {
+			return nil, err
+		}
+		p := client.HTTP01ChallengePath(chal.Token)
+		m.putHTTPToken(ctx, p, resp)
+		return func() { go m.deleteHTTPToken(p) }, nil
 	}
-	m.putTokenCert(ctx, name, &cert)
-	defer func() {
-		// verification has ended at this point
-		// don't need token cert anymore
-		go m.deleteTokenCert(name)
-	}()
+	return nil, fmt.Errorf("acme/autocert: unknown challenge type %q", chal.Type)
+}
 
-	// ready to fulfill the challenge
-	if _, err := client.Accept(ctx, chal); err != nil {
-		return err
+func pickChallenge(typ string, chal []*acme.Challenge) *acme.Challenge {
+	for _, c := range chal {
+		if c.Type == typ {
+			return c
+		}
 	}
-	// wait for the CA to validate
-	_, err = client.WaitAuthorization(ctx, authz.URI)
-	return err
+	return nil
 }
 
-// putTokenCert stores the cert under the named key in both m.tokenCert map
+// putCertToken stores the cert under the named key in both m.certTokens map
 // and m.Cache.
-func (m *Manager) putTokenCert(ctx context.Context, name string, cert *tls.Certificate) {
-	m.tokenCertMu.Lock()
-	defer m.tokenCertMu.Unlock()
-	if m.tokenCert == nil {
-		m.tokenCert = make(map[string]*tls.Certificate)
+func (m *Manager) putCertToken(ctx context.Context, name string, cert *tls.Certificate) {
+	m.tokensMu.Lock()
+	defer m.tokensMu.Unlock()
+	if m.certTokens == nil {
+		m.certTokens = make(map[string]*tls.Certificate)
 	}
-	m.tokenCert[name] = cert
+	m.certTokens[name] = cert
 	m.cachePut(ctx, name, cert)
 }
 
-// deleteTokenCert removes the token certificate for the specified domain name
-// from both m.tokenCert map and m.Cache.
-func (m *Manager) deleteTokenCert(name string) {
-	m.tokenCertMu.Lock()
-	defer m.tokenCertMu.Unlock()
-	delete(m.tokenCert, name)
+// deleteCertToken removes the token certificate for the specified domain name
+// from both m.certTokens map and m.Cache.
+func (m *Manager) deleteCertToken(name string) {
+	m.tokensMu.Lock()
+	defer m.tokensMu.Unlock()
+	delete(m.certTokens, name)
 	if m.Cache != nil {
 		m.Cache.Delete(context.Background(), name)
 	}
 }
 
+// httpToken retrieves an existing http-01 token value from an in-memory map
+// or the optional cache.
+func (m *Manager) httpToken(ctx context.Context, tokenPath string) ([]byte, error) {
+	m.tokensMu.RLock()
+	defer m.tokensMu.RUnlock()
+	if v, ok := m.httpTokens[tokenPath]; ok {
+		return v, nil
+	}
+	if m.Cache == nil {
+		return nil, fmt.Errorf("acme/autocert: no token at %q", tokenPath)
+	}
+	return m.Cache.Get(ctx, httpTokenCacheKey(tokenPath))
+}
+
+// putHTTPToken stores an http-01 token value using tokenPath as key
+// in both in-memory map and the optional Cache.
+//
+// It ignores any error returned from Cache.Put.
+func (m *Manager) putHTTPToken(ctx context.Context, tokenPath, val string) {
+	m.tokensMu.Lock()
+	defer m.tokensMu.Unlock()
+	if m.httpTokens == nil {
+		m.httpTokens = make(map[string][]byte)
+	}
+	b := []byte(val)
+	m.httpTokens[tokenPath] = b
+	if m.Cache != nil {
+		m.Cache.Put(ctx, httpTokenCacheKey(tokenPath), b)
+	}
+}
+
+// deleteHTTPToken removes an http-01 token value from both in-memory map
+// and the optional Cache, ignoring any error returned from the latter.
+//
+// If m.Cache is non-nil, it blocks until Cache.Delete returns without a timeout.
+func (m *Manager) deleteHTTPToken(tokenPath string) {
+	m.tokensMu.Lock()
+	defer m.tokensMu.Unlock()
+	delete(m.httpTokens, tokenPath)
+	if m.Cache != nil {
+		m.Cache.Delete(context.Background(), httpTokenCacheKey(tokenPath))
+	}
+}
+
+// httpTokenCacheKey returns a key at which an http-01 token value may be stored
+// in the Manager's optional Cache.
+func httpTokenCacheKey(tokenPath string) string {
+	return "http-01-" + path.Base(tokenPath)
+}
+
 // renew starts a cert renewal timer loop, one per domain.
 //
 // The loop is scheduled in two cases:
diff --git a/vendor/golang.org/x/crypto/acme/autocert/autocert_test.go b/vendor/golang.org/x/crypto/acme/autocert/autocert_test.go
index 43a6201..2da1912 100644
--- a/vendor/golang.org/x/crypto/acme/autocert/autocert_test.go
+++ b/vendor/golang.org/x/crypto/acme/autocert/autocert_test.go
@@ -23,6 +23,7 @@ import (
 	"net/http"
 	"net/http/httptest"
 	"reflect"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -48,6 +49,16 @@ var authzTmpl = template.Must(template.New("authz").Parse(`{
 			"uri": "{{.}}/challenge/2",
 			"type": "tls-sni-02",
 			"token": "token-02"
+		},
+		{
+			"uri": "{{.}}/challenge/dns-01",
+			"type": "dns-01",
+			"token": "token-dns-01"
+		},
+		{
+			"uri": "{{.}}/challenge/http-01",
+			"type": "http-01",
+			"token": "token-http-01"
 		}
 	]
 }`))
@@ -419,6 +430,146 @@ func testGetCertificate(t *testing.T, man *Manager, domain string, hello *tls.Cl
 
 }
 
+func TestVerifyHTTP01(t *testing.T) {
+	var (
+		http01 http.Handler
+
+		authzCount      int // num. of created authorizations
+		didAcceptHTTP01 bool
+	)
+
+	verifyHTTPToken := func() {
+		r := httptest.NewRequest("GET", "/.well-known/acme-challenge/token-http-01", nil)
+		w := httptest.NewRecorder()
+		http01.ServeHTTP(w, r)
+		if w.Code != http.StatusOK {
+			t.Errorf("http token: w.Code = %d; want %d", w.Code, http.StatusOK)
+		}
+		if v := string(w.Body.Bytes()); !strings.HasPrefix(v, "token-http-01.") {
+			t.Errorf("http token value = %q; want 'token-http-01.' prefix", v)
+		}
+	}
+
+	// ACME CA server stub, only the needed bits.
+	// TODO: Merge this with startACMEServerStub, making it a configurable CA for testing.
+	var ca *httptest.Server
+	ca = httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Set("Replay-Nonce", "nonce")
+		if r.Method == "HEAD" {
+			// a nonce request
+			return
+		}
+
+		switch r.URL.Path {
+		// Discovery.
+		case "/":
+			if err := discoTmpl.Execute(w, ca.URL); err != nil {
+				t.Errorf("discoTmpl: %v", err)
+			}
+		// Client key registration.
+		case "/new-reg":
+			w.Write([]byte("{}"))
+		// New domain authorization.
+		case "/new-authz":
+			authzCount++
+			w.Header().Set("Location", fmt.Sprintf("%s/authz/%d", ca.URL, authzCount))
+			w.WriteHeader(http.StatusCreated)
+			if err := authzTmpl.Execute(w, ca.URL); err != nil {
+				t.Errorf("authzTmpl: %v", err)
+			}
+		// Accept tls-sni-02.
+		case "/challenge/2":
+			w.Write([]byte("{}"))
+		// Reject tls-sni-01.
+		case "/challenge/1":
+			http.Error(w, "won't accept tls-sni-01", http.StatusBadRequest)
+		// Should not accept dns-01.
+		case "/challenge/dns-01":
+			t.Errorf("dns-01 challenge was accepted")
+			http.Error(w, "won't accept dns-01", http.StatusBadRequest)
+		// Accept http-01.
+		case "/challenge/http-01":
+			didAcceptHTTP01 = true
+			verifyHTTPToken()
+			w.Write([]byte("{}"))
+		// Authorization statuses.
+		// Make tls-sni-xxx invalid.
+		case "/authz/1", "/authz/2":
+			w.Write([]byte(`{"status": "invalid"}`))
+		case "/authz/3", "/authz/4":
+			w.Write([]byte(`{"status": "valid"}`))
+		default:
+			http.NotFound(w, r)
+			t.Errorf("unrecognized r.URL.Path: %s", r.URL.Path)
+		}
+	}))
+	defer ca.Close()
+
+	key, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	m := &Manager{
+		Client: &acme.Client{
+			Key:          key,
+			DirectoryURL: ca.URL,
+		},
+	}
+	http01 = m.HTTPHandler(nil)
+	if err := m.verify(context.Background(), m.Client, "example.org"); err != nil {
+		t.Errorf("m.verify: %v", err)
+	}
+	// Only tls-sni-01, tls-sni-02 and http-01 must be accepted
+	// The dns-01 challenge is unsupported.
+	if authzCount != 3 {
+		t.Errorf("authzCount = %d; want 3", authzCount)
+	}
+	if !didAcceptHTTP01 {
+		t.Error("did not accept http-01 challenge")
+	}
+}
+
+func TestHTTPHandlerDefaultFallback(t *testing.T) {
+	tt := []struct {
+		method, url  string
+		wantCode     int
+		wantLocation string
+	}{
+		{"GET", "http://example.org", 302, "https://example.org/"},
+		{"GET", "http://example.org/foo", 302, "https://example.org/foo"},
+		{"GET", "http://example.org/foo/bar/", 302, "https://example.org/foo/bar/"},
+		{"GET", "http://example.org/?a=b", 302, "https://example.org/?a=b"},
+		{"GET", "http://example.org/foo?a=b", 302, "https://example.org/foo?a=b"},
+		{"GET", "http://example.org:80/foo?a=b", 302, "https://example.org:443/foo?a=b"},
+		{"GET", "http://example.org:80/foo%20bar", 302, "https://example.org:443/foo%20bar"},
+		{"GET", "http://[2602:d1:xxxx::c60a]:1234", 302, "https://[2602:d1:xxxx::c60a]:443/"},
+		{"GET", "http://[2602:d1:xxxx::c60a]", 302, "https://[2602:d1:xxxx::c60a]/"},
+		{"GET", "http://[2602:d1:xxxx::c60a]/foo?a=b", 302, "https://[2602:d1:xxxx::c60a]/foo?a=b"},
+		{"HEAD", "http://example.org", 302, "https://example.org/"},
+		{"HEAD", "http://example.org/foo", 302, "https://example.org/foo"},
+		{"HEAD", "http://example.org/foo/bar/", 302, "https://example.org/foo/bar/"},
+		{"HEAD", "http://example.org/?a=b", 302, "https://example.org/?a=b"},
+		{"HEAD", "http://example.org/foo?a=b", 302, "https://example.org/foo?a=b"},
+		{"POST", "http://example.org", 400, ""},
+		{"PUT", "http://example.org", 400, ""},
+		{"GET", "http://example.org/.well-known/acme-challenge/x", 404, ""},
+	}
+	var m Manager
+	h := m.HTTPHandler(nil)
+	for i, test := range tt {
+		r := httptest.NewRequest(test.method, test.url, nil)
+		w := httptest.NewRecorder()
+		h.ServeHTTP(w, r)
+		if w.Code != test.wantCode {
+			t.Errorf("%d: w.Code = %d; want %d", i, w.Code, test.wantCode)
+			t.Errorf("%d: body: %s", i, w.Body.Bytes())
+		}
+		if v := w.Header().Get("Location"); v != test.wantLocation {
+			t.Errorf("%d: Location = %q; want %q", i, v, test.wantLocation)
+		}
+	}
+}
+
 func TestAccountKeyCache(t *testing.T) {
 	m := Manager{Cache: newMemCache()}
 	ctx := context.Background()
diff --git a/vendor/golang.org/x/crypto/acme/autocert/example_test.go b/vendor/golang.org/x/crypto/acme/autocert/example_test.go
index 71d61eb..552a625 100644
--- a/vendor/golang.org/x/crypto/acme/autocert/example_test.go
+++ b/vendor/golang.org/x/crypto/acme/autocert/example_test.go
@@ -22,11 +22,12 @@ func ExampleNewListener() {
 }
 
 func ExampleManager() {
-	m := autocert.Manager{
+	m := &autocert.Manager{
 		Cache:      autocert.DirCache("secret-dir"),
 		Prompt:     autocert.AcceptTOS,
 		HostPolicy: autocert.HostWhitelist("example.org"),
 	}
+	go http.ListenAndServe(":http", m.HTTPHandler(nil))
 	s := &http.Server{
 		Addr:      ":https",
 		TLSConfig: &tls.Config{GetCertificate: m.GetCertificate},
diff --git a/vendor/golang.org/x/crypto/argon2/argon2.go b/vendor/golang.org/x/crypto/argon2/argon2.go
new file mode 100644
index 0000000..71cf8c5
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/argon2.go
@@ -0,0 +1,228 @@
+// 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 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
+package argon2
+
+import (
+	"encoding/binary"
+	"sync"
+
+	"golang.org/x/crypto/blake2b"
+)
+
+// The Argon2 version implemented by this package.
+const Version = 0x13
+
+const (
+	argon2d = iota
+	argon2i
+	argon2id
+)
+
+// 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.
+//
+// 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)`
+//
+// 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.
+func Key(password, salt []byte, time, memory uint32, threads uint8, keyLen uint32) []byte {
+	return deriveKey(argon2i, 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")
+	}
+	if threads < 1 {
+		panic("argon2: parallelism degree too low")
+	}
+	h0 := initHash(password, salt, secret, data, time, memory, uint32(threads), keyLen, mode)
+
+	memory = memory / (syncPoints * uint32(threads)) * (syncPoints * uint32(threads))
+	if memory < 2*syncPoints*uint32(threads) {
+		memory = 2 * syncPoints * uint32(threads)
+	}
+	B := initBlocks(&h0, memory, uint32(threads))
+	processBlocks(B, time, memory, uint32(threads), mode)
+	return extractKey(B, memory, uint32(threads), keyLen)
+}
+
+const (
+	blockLength = 128
+	syncPoints  = 4
+)
+
+type block [blockLength]uint64
+
+func initHash(password, salt, key, data []byte, time, memory, threads, keyLen uint32, mode int) [blake2b.Size + 8]byte {
+	var (
+		h0     [blake2b.Size + 8]byte
+		params [24]byte
+		tmp    [4]byte
+	)
+
+	b2, _ := blake2b.New512(nil)
+	binary.LittleEndian.PutUint32(params[0:4], threads)
+	binary.LittleEndian.PutUint32(params[4:8], keyLen)
+	binary.LittleEndian.PutUint32(params[8:12], memory)
+	binary.LittleEndian.PutUint32(params[12:16], time)
+	binary.LittleEndian.PutUint32(params[16:20], uint32(Version))
+	binary.LittleEndian.PutUint32(params[20:24], uint32(mode))
+	b2.Write(params[:])
+	binary.LittleEndian.PutUint32(tmp[:], uint32(len(password)))
+	b2.Write(tmp[:])
+	b2.Write(password)
+	binary.LittleEndian.PutUint32(tmp[:], uint32(len(salt)))
+	b2.Write(tmp[:])
+	b2.Write(salt)
+	binary.LittleEndian.PutUint32(tmp[:], uint32(len(key)))
+	b2.Write(tmp[:])
+	b2.Write(key)
+	binary.LittleEndian.PutUint32(tmp[:], uint32(len(data)))
+	b2.Write(tmp[:])
+	b2.Write(data)
+	b2.Sum(h0[:0])
+	return h0
+}
+
+func initBlocks(h0 *[blake2b.Size + 8]byte, memory, threads uint32) []block {
+	var block0 [1024]byte
+	B := make([]block, memory)
+	for lane := uint32(0); lane < threads; lane++ {
+		j := lane * (memory / threads)
+		binary.LittleEndian.PutUint32(h0[blake2b.Size+4:], lane)
+
+		binary.LittleEndian.PutUint32(h0[blake2b.Size:], 0)
+		blake2bHash(block0[:], h0[:])
+		for i := range B[j+0] {
+			B[j+0][i] = binary.LittleEndian.Uint64(block0[i*8:])
+		}
+
+		binary.LittleEndian.PutUint32(h0[blake2b.Size:], 1)
+		blake2bHash(block0[:], h0[:])
+		for i := range B[j+1] {
+			B[j+1][i] = binary.LittleEndian.Uint64(block0[i*8:])
+		}
+	}
+	return B
+}
+
+func processBlocks(B []block, time, memory, threads uint32, mode int) {
+	lanes := memory / threads
+	segments := lanes / syncPoints
+
+	processSegment := func(n, slice, lane uint32, wg *sync.WaitGroup) {
+		var addresses, in, zero block
+		if mode == argon2i || (mode == argon2id && n == 0 && slice < syncPoints/2) {
+			in[0] = uint64(n)
+			in[1] = uint64(lane)
+			in[2] = uint64(slice)
+			in[3] = uint64(memory)
+			in[4] = uint64(time)
+			in[5] = uint64(mode)
+		}
+
+		index := uint32(0)
+		if n == 0 && slice == 0 {
+			index = 2 // we have already generated the first two blocks
+			if mode == argon2i || mode == argon2id {
+				in[6]++
+				processBlock(&addresses, &in, &zero)
+				processBlock(&addresses, &addresses, &zero)
+			}
+		}
+
+		offset := lane*lanes + slice*segments + index
+		var random uint64
+		for index < segments {
+			prev := offset - 1
+			if index == 0 && slice == 0 {
+				prev += lanes // last block in lane
+			}
+			if mode == argon2i || (mode == argon2id && n == 0 && slice < syncPoints/2) {
+				if index%blockLength == 0 {
+					in[6]++
+					processBlock(&addresses, &in, &zero)
+					processBlock(&addresses, &addresses, &zero)
+				}
+				random = addresses[index%blockLength]
+			} else {
+				random = B[prev][0]
+			}
+			newOffset := indexAlpha(random, lanes, segments, threads, n, slice, lane, index)
+			processBlockXOR(&B[offset], &B[prev], &B[newOffset])
+			index, offset = index+1, offset+1
+		}
+		wg.Done()
+	}
+
+	for n := uint32(0); n < time; n++ {
+		for slice := uint32(0); slice < syncPoints; slice++ {
+			var wg sync.WaitGroup
+			for lane := uint32(0); lane < threads; lane++ {
+				wg.Add(1)
+				go processSegment(n, slice, lane, &wg)
+			}
+			wg.Wait()
+		}
+	}
+
+}
+
+func extractKey(B []block, memory, threads, keyLen uint32) []byte {
+	lanes := memory / threads
+	for lane := uint32(0); lane < threads-1; lane++ {
+		for i, v := range B[(lane*lanes)+lanes-1] {
+			B[memory-1][i] ^= v
+		}
+	}
+
+	var block [1024]byte
+	for i, v := range B[memory-1] {
+		binary.LittleEndian.PutUint64(block[i*8:], v)
+	}
+	key := make([]byte, keyLen)
+	blake2bHash(key, block[:])
+	return key
+}
+
+func indexAlpha(rand uint64, lanes, segments, threads, n, slice, lane, index uint32) uint32 {
+	refLane := uint32(rand>>32) % threads
+	if n == 0 && slice == 0 {
+		refLane = lane
+	}
+	m, s := 3*segments, ((slice+1)%syncPoints)*segments
+	if lane == refLane {
+		m += index
+	}
+	if n == 0 {
+		m, s = slice*segments, 0
+		if slice == 0 || lane == refLane {
+			m += index
+		}
+	}
+	if index == 0 || lane == refLane {
+		m--
+	}
+	return phi(rand, uint64(m), uint64(s), refLane, lanes)
+}
+
+func phi(rand, m, s uint64, lane, lanes uint32) uint32 {
+	p := rand & 0xFFFFFFFF
+	p = (p * p) >> 32
+	p = (p * m) >> 32
+	return lane*lanes + uint32((s+m-(p+1))%uint64(lanes))
+}
diff --git a/vendor/golang.org/x/crypto/argon2/argon2_test.go b/vendor/golang.org/x/crypto/argon2/argon2_test.go
new file mode 100644
index 0000000..775b97a
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/argon2_test.go
@@ -0,0 +1,233 @@
+// 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 argon2
+
+import (
+	"bytes"
+	"encoding/hex"
+	"testing"
+)
+
+var (
+	genKatPassword = []byte{
+		0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+		0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+	}
+	genKatSalt   = []byte{0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02}
+	genKatSecret = []byte{0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03, 0x03}
+	genKatAAD    = []byte{0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04}
+)
+
+func TestArgon2(t *testing.T) {
+	defer func(sse4 bool) { useSSE4 = sse4 }(useSSE4)
+
+	if useSSE4 {
+		t.Log("SSE4.1 version")
+		testArgon2i(t)
+		testArgon2d(t)
+		testArgon2id(t)
+		useSSE4 = false
+	}
+	t.Log("generic version")
+	testArgon2i(t)
+	testArgon2d(t)
+	testArgon2id(t)
+}
+
+func testArgon2d(t *testing.T) {
+	want := []byte{
+		0x51, 0x2b, 0x39, 0x1b, 0x6f, 0x11, 0x62, 0x97,
+		0x53, 0x71, 0xd3, 0x09, 0x19, 0x73, 0x42, 0x94,
+		0xf8, 0x68, 0xe3, 0xbe, 0x39, 0x84, 0xf3, 0xc1,
+		0xa1, 0x3a, 0x4d, 0xb9, 0xfa, 0xbe, 0x4a, 0xcb,
+	}
+	hash := deriveKey(argon2d, genKatPassword, genKatSalt, genKatSecret, genKatAAD, 3, 32, 4, 32)
+	if !bytes.Equal(hash, want) {
+		t.Errorf("derived key does not match - got: %s , want: %s", hex.EncodeToString(hash), hex.EncodeToString(want))
+	}
+}
+
+func testArgon2i(t *testing.T) {
+	want := []byte{
+		0xc8, 0x14, 0xd9, 0xd1, 0xdc, 0x7f, 0x37, 0xaa,
+		0x13, 0xf0, 0xd7, 0x7f, 0x24, 0x94, 0xbd, 0xa1,
+		0xc8, 0xde, 0x6b, 0x01, 0x6d, 0xd3, 0x88, 0xd2,
+		0x99, 0x52, 0xa4, 0xc4, 0x67, 0x2b, 0x6c, 0xe8,
+	}
+	hash := deriveKey(argon2i, genKatPassword, genKatSalt, genKatSecret, genKatAAD, 3, 32, 4, 32)
+	if !bytes.Equal(hash, want) {
+		t.Errorf("derived key does not match - got: %s , want: %s", hex.EncodeToString(hash), hex.EncodeToString(want))
+	}
+}
+
+func testArgon2id(t *testing.T) {
+	want := []byte{
+		0x0d, 0x64, 0x0d, 0xf5, 0x8d, 0x78, 0x76, 0x6c,
+		0x08, 0xc0, 0x37, 0xa3, 0x4a, 0x8b, 0x53, 0xc9,
+		0xd0, 0x1e, 0xf0, 0x45, 0x2d, 0x75, 0xb6, 0x5e,
+		0xb5, 0x25, 0x20, 0xe9, 0x6b, 0x01, 0xe6, 0x59,
+	}
+	hash := deriveKey(argon2id, genKatPassword, genKatSalt, genKatSecret, genKatAAD, 3, 32, 4, 32)
+	if !bytes.Equal(hash, want) {
+		t.Errorf("derived key does not match - got: %s , want: %s", hex.EncodeToString(hash), hex.EncodeToString(want))
+	}
+}
+
+func TestVectors(t *testing.T) {
+	password, salt := []byte("password"), []byte("somesalt")
+	for i, v := range testVectors {
+		want, err := hex.DecodeString(v.hash)
+		if err != nil {
+			t.Fatalf("Test %d: failed to decode hash: %v", i, err)
+		}
+		hash := deriveKey(v.mode, password, salt, nil, nil, v.time, v.memory, v.threads, uint32(len(want)))
+		if !bytes.Equal(hash, want) {
+			t.Errorf("Test %d - got: %s want: %s", i, hex.EncodeToString(hash), hex.EncodeToString(want))
+		}
+	}
+}
+
+func benchmarkArgon2(mode int, time, memory uint32, threads uint8, keyLen uint32, b *testing.B) {
+	password := []byte("password")
+	salt := []byte("choosing random salts is hard")
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		deriveKey(mode, password, salt, nil, nil, time, memory, threads, keyLen)
+	}
+}
+
+func BenchmarkArgon2i(b *testing.B) {
+	b.Run(" Time: 3 Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2i, 3, 32*1024, 1, 32, b) })
+	b.Run(" Time: 4 Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2i, 4, 32*1024, 1, 32, b) })
+	b.Run(" Time: 5 Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2i, 5, 32*1024, 1, 32, b) })
+	b.Run(" Time: 3 Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2i, 3, 64*1024, 4, 32, b) })
+	b.Run(" Time: 4 Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2i, 4, 64*1024, 4, 32, b) })
+	b.Run(" Time: 5 Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2i, 5, 64*1024, 4, 32, b) })
+}
+
+func BenchmarkArgon2d(b *testing.B) {
+	b.Run(" Time: 3, Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2d, 3, 32*1024, 1, 32, b) })
+	b.Run(" Time: 4, Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2d, 4, 32*1024, 1, 32, b) })
+	b.Run(" Time: 5, Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2d, 5, 32*1024, 1, 32, b) })
+	b.Run(" Time: 3, Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2d, 3, 64*1024, 4, 32, b) })
+	b.Run(" Time: 4, Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2d, 4, 64*1024, 4, 32, b) })
+	b.Run(" Time: 5, Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2d, 5, 64*1024, 4, 32, b) })
+}
+
+func BenchmarkArgon2id(b *testing.B) {
+	b.Run(" Time: 3, Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2id, 3, 32*1024, 1, 32, b) })
+	b.Run(" Time: 4, Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2id, 4, 32*1024, 1, 32, b) })
+	b.Run(" Time: 5, Memory: 32 MB, Threads: 1", func(b *testing.B) { benchmarkArgon2(argon2id, 5, 32*1024, 1, 32, b) })
+	b.Run(" Time: 3, Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2id, 3, 64*1024, 4, 32, b) })
+	b.Run(" Time: 4, Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2id, 4, 64*1024, 4, 32, b) })
+	b.Run(" Time: 5, Memory: 64 MB, Threads: 4", func(b *testing.B) { benchmarkArgon2(argon2id, 5, 64*1024, 4, 32, b) })
+}
+
+// Generated with the CLI of https://github.com/P-H-C/phc-winner-argon2/blob/master/argon2-specs.pdf
+var testVectors = []struct {
+	mode         int
+	time, memory uint32
+	threads      uint8
+	hash         string
+}{
+	{
+		mode: argon2i, time: 1, memory: 64, threads: 1,
+		hash: "b9c401d1844a67d50eae3967dc28870b22e508092e861a37",
+	},
+	{
+		mode: argon2d, time: 1, memory: 64, threads: 1,
+		hash: "8727405fd07c32c78d64f547f24150d3f2e703a89f981a19",
+	},
+	{
+		mode: argon2id, time: 1, memory: 64, threads: 1,
+		hash: "655ad15eac652dc59f7170a7332bf49b8469be1fdb9c28bb",
+	},
+	{
+		mode: argon2i, time: 2, memory: 64, threads: 1,
+		hash: "8cf3d8f76a6617afe35fac48eb0b7433a9a670ca4a07ed64",
+	},
+	{
+		mode: argon2d, time: 2, memory: 64, threads: 1,
+		hash: "3be9ec79a69b75d3752acb59a1fbb8b295a46529c48fbb75",
+	},
+	{
+		mode: argon2id, time: 2, memory: 64, threads: 1,
+		hash: "068d62b26455936aa6ebe60060b0a65870dbfa3ddf8d41f7",
+	},
+	{
+		mode: argon2i, time: 2, memory: 64, threads: 2,
+		hash: "2089f3e78a799720f80af806553128f29b132cafe40d059f",
+	},
+	{
+		mode: argon2d, time: 2, memory: 64, threads: 2,
+		hash: "68e2462c98b8bc6bb60ec68db418ae2c9ed24fc6748a40e9",
+	},
+	{
+		mode: argon2id, time: 2, memory: 64, threads: 2,
+		hash: "350ac37222f436ccb5c0972f1ebd3bf6b958bf2071841362",
+	},
+	{
+		mode: argon2i, time: 3, memory: 256, threads: 2,
+		hash: "f5bbf5d4c3836af13193053155b73ec7476a6a2eb93fd5e6",
+	},
+	{
+		mode: argon2d, time: 3, memory: 256, threads: 2,
+		hash: "f4f0669218eaf3641f39cc97efb915721102f4b128211ef2",
+	},
+	{
+		mode: argon2id, time: 3, memory: 256, threads: 2,
+		hash: "4668d30ac4187e6878eedeacf0fd83c5a0a30db2cc16ef0b",
+	},
+	{
+		mode: argon2i, time: 4, memory: 4096, threads: 4,
+		hash: "a11f7b7f3f93f02ad4bddb59ab62d121e278369288a0d0e7",
+	},
+	{
+		mode: argon2d, time: 4, memory: 4096, threads: 4,
+		hash: "935598181aa8dc2b720914aa6435ac8d3e3a4210c5b0fb2d",
+	},
+	{
+		mode: argon2id, time: 4, memory: 4096, threads: 4,
+		hash: "145db9733a9f4ee43edf33c509be96b934d505a4efb33c5a",
+	},
+	{
+		mode: argon2i, time: 4, memory: 1024, threads: 8,
+		hash: "0cdd3956aa35e6b475a7b0c63488822f774f15b43f6e6e17",
+	},
+	{
+		mode: argon2d, time: 4, memory: 1024, threads: 8,
+		hash: "83604fc2ad0589b9d055578f4d3cc55bc616df3578a896e9",
+	},
+	{
+		mode: argon2id, time: 4, memory: 1024, threads: 8,
+		hash: "8dafa8e004f8ea96bf7c0f93eecf67a6047476143d15577f",
+	},
+	{
+		mode: argon2i, time: 2, memory: 64, threads: 3,
+		hash: "5cab452fe6b8479c8661def8cd703b611a3905a6d5477fe6",
+	},
+	{
+		mode: argon2d, time: 2, memory: 64, threads: 3,
+		hash: "22474a423bda2ccd36ec9afd5119e5c8949798cadf659f51",
+	},
+	{
+		mode: argon2id, time: 2, memory: 64, threads: 3,
+		hash: "4a15b31aec7c2590b87d1f520be7d96f56658172deaa3079",
+	},
+	{
+		mode: argon2i, time: 3, memory: 1024, threads: 6,
+		hash: "d236b29c2b2a09babee842b0dec6aa1e83ccbdea8023dced",
+	},
+	{
+		mode: argon2d, time: 3, memory: 1024, threads: 6,
+		hash: "a3351b0319a53229152023d9206902f4ef59661cdca89481",
+	},
+	{
+		mode: argon2id, time: 3, memory: 1024, threads: 6,
+		hash: "1640b932f4b60e272f5d2207b9a9c626ffa1bd88d2349016",
+	},
+}
diff --git a/vendor/golang.org/x/crypto/argon2/blake2b.go b/vendor/golang.org/x/crypto/argon2/blake2b.go
new file mode 100644
index 0000000..10f4694
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/blake2b.go
@@ -0,0 +1,53 @@
+// 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 argon2
+
+import (
+	"encoding/binary"
+	"hash"
+
+	"golang.org/x/crypto/blake2b"
+)
+
+// blake2bHash computes an arbitrary long hash value of in
+// and writes the hash to out.
+func blake2bHash(out []byte, in []byte) {
+	var b2 hash.Hash
+	if n := len(out); n < blake2b.Size {
+		b2, _ = blake2b.New(n, nil)
+	} else {
+		b2, _ = blake2b.New512(nil)
+	}
+
+	var buffer [blake2b.Size]byte
+	binary.LittleEndian.PutUint32(buffer[:4], uint32(len(out)))
+	b2.Write(buffer[:4])
+	b2.Write(in)
+
+	if len(out) <= blake2b.Size {
+		b2.Sum(out[:0])
+		return
+	}
+
+	outLen := len(out)
+	b2.Sum(buffer[:0])
+	b2.Reset()
+	copy(out, buffer[:32])
+	out = out[32:]
+	for len(out) > blake2b.Size {
+		b2.Write(buffer[:])
+		b2.Sum(buffer[:0])
+		copy(out, buffer[:32])
+		out = out[32:]
+		b2.Reset()
+	}
+
+	if outLen%blake2b.Size > 0 { // outLen > 64
+		r := ((outLen + 31) / 32) - 2 // ⌈τ /32⌉-2
+		b2, _ = blake2b.New(outLen-32*r, nil)
+	}
+	b2.Write(buffer[:])
+	b2.Sum(out[:0])
+}
diff --git a/vendor/golang.org/x/crypto/argon2/blamka_amd64.go b/vendor/golang.org/x/crypto/argon2/blamka_amd64.go
new file mode 100644
index 0000000..bb2b0d8
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/blamka_amd64.go
@@ -0,0 +1,61 @@
+// 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.
+
+// +build amd64,!gccgo,!appengine
+
+package argon2
+
+func init() {
+	useSSE4 = supportsSSE4()
+}
+
+//go:noescape
+func supportsSSE4() bool
+
+//go:noescape
+func mixBlocksSSE2(out, a, b, c *block)
+
+//go:noescape
+func xorBlocksSSE2(out, a, b, c *block)
+
+//go:noescape
+func blamkaSSE4(b *block)
+
+func processBlockSSE(out, in1, in2 *block, xor bool) {
+	var t block
+	mixBlocksSSE2(&t, in1, in2, &t)
+	if useSSE4 {
+		blamkaSSE4(&t)
+	} else {
+		for i := 0; i < blockLength; i += 16 {
+			blamkaGeneric(
+				&t[i+0], &t[i+1], &t[i+2], &t[i+3],
+				&t[i+4], &t[i+5], &t[i+6], &t[i+7],
+				&t[i+8], &t[i+9], &t[i+10], &t[i+11],
+				&t[i+12], &t[i+13], &t[i+14], &t[i+15],
+			)
+		}
+		for i := 0; i < blockLength/8; i += 2 {
+			blamkaGeneric(
+				&t[i], &t[i+1], &t[16+i], &t[16+i+1],
+				&t[32+i], &t[32+i+1], &t[48+i], &t[48+i+1],
+				&t[64+i], &t[64+i+1], &t[80+i], &t[80+i+1],
+				&t[96+i], &t[96+i+1], &t[112+i], &t[112+i+1],
+			)
+		}
+	}
+	if xor {
+		xorBlocksSSE2(out, in1, in2, &t)
+	} else {
+		mixBlocksSSE2(out, in1, in2, &t)
+	}
+}
+
+func processBlock(out, in1, in2 *block) {
+	processBlockSSE(out, in1, in2, false)
+}
+
+func processBlockXOR(out, in1, in2 *block) {
+	processBlockSSE(out, in1, in2, true)
+}
diff --git a/vendor/golang.org/x/crypto/argon2/blamka_amd64.s b/vendor/golang.org/x/crypto/argon2/blamka_amd64.s
new file mode 100644
index 0000000..8a83f7c
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/blamka_amd64.s
@@ -0,0 +1,252 @@
+// 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.
+
+// +build amd64,!gccgo,!appengine
+
+#include "textflag.h"
+
+DATA ·c40<>+0x00(SB)/8, $0x0201000706050403
+DATA ·c40<>+0x08(SB)/8, $0x0a09080f0e0d0c0b
+GLOBL ·c40<>(SB), (NOPTR+RODATA), $16
+
+DATA ·c48<>+0x00(SB)/8, $0x0100070605040302
+DATA ·c48<>+0x08(SB)/8, $0x09080f0e0d0c0b0a
+GLOBL ·c48<>(SB), (NOPTR+RODATA), $16
+
+#define SHUFFLE(v2, v3, v4, v5, v6, v7, t1, t2) \
+	MOVO       v4, t1; \
+	MOVO       v5, v4; \
+	MOVO       t1, v5; \
+	MOVO       v6, t1; \
+	PUNPCKLQDQ v6, t2; \
+	PUNPCKHQDQ v7, v6; \
+	PUNPCKHQDQ t2, v6; \
+	PUNPCKLQDQ v7, t2; \
+	MOVO       t1, v7; \
+	MOVO       v2, t1; \
+	PUNPCKHQDQ t2, v7; \
+	PUNPCKLQDQ v3, t2; \
+	PUNPCKHQDQ t2, v2; \
+	PUNPCKLQDQ t1, t2; \
+	PUNPCKHQDQ t2, v3
+
+#define SHUFFLE_INV(v2, v3, v4, v5, v6, v7, t1, t2) \
+	MOVO       v4, t1; \
+	MOVO       v5, v4; \
+	MOVO       t1, v5; \
+	MOVO       v2, t1; \
+	PUNPCKLQDQ v2, t2; \
+	PUNPCKHQDQ v3, v2; \
+	PUNPCKHQDQ t2, v2; \
+	PUNPCKLQDQ v3, t2; \
+	MOVO       t1, v3; \
+	MOVO       v6, t1; \
+	PUNPCKHQDQ t2, v3; \
+	PUNPCKLQDQ v7, t2; \
+	PUNPCKHQDQ t2, v6; \
+	PUNPCKLQDQ t1, t2; \
+	PUNPCKHQDQ t2, v7
+
+#define HALF_ROUND(v0, v1, v2, v3, v4, v5, v6, v7, t0, c40, c48) \
+	MOVO    v0, t0;        \
+	PMULULQ v2, t0;        \
+	PADDQ   v2, v0;        \
+	PADDQ   t0, v0;        \
+	PADDQ   t0, v0;        \
+	PXOR    v0, v6;        \
+	PSHUFD  $0xB1, v6, v6; \
+	MOVO    v4, t0;        \
+	PMULULQ v6, t0;        \
+	PADDQ   v6, v4;        \
+	PADDQ   t0, v4;        \
+	PADDQ   t0, v4;        \
+	PXOR    v4, v2;        \
+	PSHUFB  c40, v2;       \
+	MOVO    v0, t0;        \
+	PMULULQ v2, t0;        \
+	PADDQ   v2, v0;        \
+	PADDQ   t0, v0;        \
+	PADDQ   t0, v0;        \
+	PXOR    v0, v6;        \
+	PSHUFB  c48, v6;       \
+	MOVO    v4, t0;        \
+	PMULULQ v6, t0;        \
+	PADDQ   v6, v4;        \
+	PADDQ   t0, v4;        \
+	PADDQ   t0, v4;        \
+	PXOR    v4, v2;        \
+	MOVO    v2, t0;        \
+	PADDQ   v2, t0;        \
+	PSRLQ   $63, v2;       \
+	PXOR    t0, v2;        \
+	MOVO    v1, t0;        \
+	PMULULQ v3, t0;        \
+	PADDQ   v3, v1;        \
+	PADDQ   t0, v1;        \
+	PADDQ   t0, v1;        \
+	PXOR    v1, v7;        \
+	PSHUFD  $0xB1, v7, v7; \
+	MOVO    v5, t0;        \
+	PMULULQ v7, t0;        \
+	PADDQ   v7, v5;        \
+	PADDQ   t0, v5;        \
+	PADDQ   t0, v5;        \
+	PXOR    v5, v3;        \
+	PSHUFB  c40, v3;       \
+	MOVO    v1, t0;        \
+	PMULULQ v3, t0;        \
+	PADDQ   v3, v1;        \
+	PADDQ   t0, v1;        \
+	PADDQ   t0, v1;        \
+	PXOR    v1, v7;        \
+	PSHUFB  c48, v7;       \
+	MOVO    v5, t0;        \
+	PMULULQ v7, t0;        \
+	PADDQ   v7, v5;        \
+	PADDQ   t0, v5;        \
+	PADDQ   t0, v5;        \
+	PXOR    v5, v3;        \
+	MOVO    v3, t0;        \
+	PADDQ   v3, t0;        \
+	PSRLQ   $63, v3;       \
+	PXOR    t0, v3
+
+#define LOAD_MSG_0(block, off) \
+	MOVOU 8*(off+0)(block), X0;  \
+	MOVOU 8*(off+2)(block), X1;  \
+	MOVOU 8*(off+4)(block), X2;  \
+	MOVOU 8*(off+6)(block), X3;  \
+	MOVOU 8*(off+8)(block), X4;  \
+	MOVOU 8*(off+10)(block), X5; \
+	MOVOU 8*(off+12)(block), X6; \
+	MOVOU 8*(off+14)(block), X7
+
+#define STORE_MSG_0(block, off) \
+	MOVOU X0, 8*(off+0)(block);  \
+	MOVOU X1, 8*(off+2)(block);  \
+	MOVOU X2, 8*(off+4)(block);  \
+	MOVOU X3, 8*(off+6)(block);  \
+	MOVOU X4, 8*(off+8)(block);  \
+	MOVOU X5, 8*(off+10)(block); \
+	MOVOU X6, 8*(off+12)(block); \
+	MOVOU X7, 8*(off+14)(block)
+
+#define LOAD_MSG_1(block, off) \
+	MOVOU 8*off+0*8(block), X0;  \
+	MOVOU 8*off+16*8(block), X1; \
+	MOVOU 8*off+32*8(block), X2; \
+	MOVOU 8*off+48*8(block), X3; \
+	MOVOU 8*off+64*8(block), X4; \
+	MOVOU 8*off+80*8(block), X5; \
+	MOVOU 8*off+96*8(block), X6; \
+	MOVOU 8*off+112*8(block), X7
+
+#define STORE_MSG_1(block, off) \
+	MOVOU X0, 8*off+0*8(block);  \
+	MOVOU X1, 8*off+16*8(block); \
+	MOVOU X2, 8*off+32*8(block); \
+	MOVOU X3, 8*off+48*8(block); \
+	MOVOU X4, 8*off+64*8(block); \
+	MOVOU X5, 8*off+80*8(block); \
+	MOVOU X6, 8*off+96*8(block); \
+	MOVOU X7, 8*off+112*8(block)
+
+#define BLAMKA_ROUND_0(block, off, t0, t1, c40, c48) \
+	LOAD_MSG_0(block, off);                                   \
+	HALF_ROUND(X0, X1, X2, X3, X4, X5, X6, X7, t0, c40, c48); \
+	SHUFFLE(X2, X3, X4, X5, X6, X7, t0, t1);                  \
+	HALF_ROUND(X0, X1, X2, X3, X4, X5, X6, X7, t0, c40, c48); \
+	SHUFFLE_INV(X2, X3, X4, X5, X6, X7, t0, t1);              \
+	STORE_MSG_0(block, off)
+
+#define BLAMKA_ROUND_1(block, off, t0, t1, c40, c48) \
+	LOAD_MSG_1(block, off);                                   \
+	HALF_ROUND(X0, X1, X2, X3, X4, X5, X6, X7, t0, c40, c48); \
+	SHUFFLE(X2, X3, X4, X5, X6, X7, t0, t1);                  \
+	HALF_ROUND(X0, X1, X2, X3, X4, X5, X6, X7, t0, c40, c48); \
+	SHUFFLE_INV(X2, X3, X4, X5, X6, X7, t0, t1);              \
+	STORE_MSG_1(block, off)
+
+// func blamkaSSE4(b *block)
+TEXT ·blamkaSSE4(SB), 4, $0-8
+	MOVQ b+0(FP), AX
+
+	MOVOU ·c40<>(SB), X10
+	MOVOU ·c48<>(SB), X11
+
+	BLAMKA_ROUND_0(AX, 0, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 16, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 32, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 48, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 64, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 80, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 96, X8, X9, X10, X11)
+	BLAMKA_ROUND_0(AX, 112, X8, X9, X10, X11)
+
+	BLAMKA_ROUND_1(AX, 0, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 2, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 4, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 6, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 8, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 10, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 12, X8, X9, X10, X11)
+	BLAMKA_ROUND_1(AX, 14, X8, X9, X10, X11)
+	RET
+
+// func mixBlocksSSE2(out, a, b, c *block)
+TEXT ·mixBlocksSSE2(SB), 4, $0-32
+	MOVQ out+0(FP), DX
+	MOVQ a+8(FP), AX
+	MOVQ b+16(FP), BX
+	MOVQ a+24(FP), CX
+	MOVQ $128, BP
+
+loop:
+	MOVOU 0(AX), X0
+	MOVOU 0(BX), X1
+	MOVOU 0(CX), X2
+	PXOR  X1, X0
+	PXOR  X2, X0
+	MOVOU X0, 0(DX)
+	ADDQ  $16, AX
+	ADDQ  $16, BX
+	ADDQ  $16, CX
+	ADDQ  $16, DX
+	SUBQ  $2, BP
+	JA    loop
+	RET
+
+// func xorBlocksSSE2(out, a, b, c *block)
+TEXT ·xorBlocksSSE2(SB), 4, $0-32
+	MOVQ out+0(FP), DX
+	MOVQ a+8(FP), AX
+	MOVQ b+16(FP), BX
+	MOVQ a+24(FP), CX
+	MOVQ $128, BP
+
+loop:
+	MOVOU 0(AX), X0
+	MOVOU 0(BX), X1
+	MOVOU 0(CX), X2
+	MOVOU 0(DX), X3
+	PXOR  X1, X0
+	PXOR  X2, X0
+	PXOR  X3, X0
+	MOVOU X0, 0(DX)
+	ADDQ  $16, AX
+	ADDQ  $16, BX
+	ADDQ  $16, CX
+	ADDQ  $16, DX
+	SUBQ  $2, BP
+	JA    loop
+	RET
+
+// func supportsSSE4() bool
+TEXT ·supportsSSE4(SB), 4, $0-1
+	MOVL $1, AX
+	CPUID
+	SHRL $19, CX       // Bit 19 indicates SSE4 support
+	ANDL $1, CX        // CX != 0 if support SSE4
+	MOVB CX, ret+0(FP)
+	RET
diff --git a/vendor/golang.org/x/crypto/argon2/blamka_generic.go b/vendor/golang.org/x/crypto/argon2/blamka_generic.go
new file mode 100644
index 0000000..a481b22
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/blamka_generic.go
@@ -0,0 +1,163 @@
+// 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 argon2
+
+var useSSE4 bool
+
+func processBlockGeneric(out, in1, in2 *block, xor bool) {
+	var t block
+	for i := range t {
+		t[i] = in1[i] ^ in2[i]
+	}
+	for i := 0; i < blockLength; i += 16 {
+		blamkaGeneric(
+			&t[i+0], &t[i+1], &t[i+2], &t[i+3],
+			&t[i+4], &t[i+5], &t[i+6], &t[i+7],
+			&t[i+8], &t[i+9], &t[i+10], &t[i+11],
+			&t[i+12], &t[i+13], &t[i+14], &t[i+15],
+		)
+	}
+	for i := 0; i < blockLength/8; i += 2 {
+		blamkaGeneric(
+			&t[i], &t[i+1], &t[16+i], &t[16+i+1],
+			&t[32+i], &t[32+i+1], &t[48+i], &t[48+i+1],
+			&t[64+i], &t[64+i+1], &t[80+i], &t[80+i+1],
+			&t[96+i], &t[96+i+1], &t[112+i], &t[112+i+1],
+		)
+	}
+	if xor {
+		for i := range t {
+			out[i] ^= in1[i] ^ in2[i] ^ t[i]
+		}
+	} else {
+		for i := range t {
+			out[i] = in1[i] ^ in2[i] ^ t[i]
+		}
+	}
+}
+
+func blamkaGeneric(t00, t01, t02, t03, t04, t05, t06, t07, t08, t09, t10, t11, t12, t13, t14, t15 *uint64) {
+	v00, v01, v02, v03 := *t00, *t01, *t02, *t03
+	v04, v05, v06, v07 := *t04, *t05, *t06, *t07
+	v08, v09, v10, v11 := *t08, *t09, *t10, *t11
+	v12, v13, v14, v15 := *t12, *t13, *t14, *t15
+
+	v00 += v04 + 2*uint64(uint32(v00))*uint64(uint32(v04))
+	v12 ^= v00
+	v12 = v12>>32 | v12<<32
+	v08 += v12 + 2*uint64(uint32(v08))*uint64(uint32(v12))
+	v04 ^= v08
+	v04 = v04>>24 | v04<<40
+
+	v00 += v04 + 2*uint64(uint32(v00))*uint64(uint32(v04))
+	v12 ^= v00
+	v12 = v12>>16 | v12<<48
+	v08 += v12 + 2*uint64(uint32(v08))*uint64(uint32(v12))
+	v04 ^= v08
+	v04 = v04>>63 | v04<<1
+
+	v01 += v05 + 2*uint64(uint32(v01))*uint64(uint32(v05))
+	v13 ^= v01
+	v13 = v13>>32 | v13<<32
+	v09 += v13 + 2*uint64(uint32(v09))*uint64(uint32(v13))
+	v05 ^= v09
+	v05 = v05>>24 | v05<<40
+
+	v01 += v05 + 2*uint64(uint32(v01))*uint64(uint32(v05))
+	v13 ^= v01
+	v13 = v13>>16 | v13<<48
+	v09 += v13 + 2*uint64(uint32(v09))*uint64(uint32(v13))
+	v05 ^= v09
+	v05 = v05>>63 | v05<<1
+
+	v02 += v06 + 2*uint64(uint32(v02))*uint64(uint32(v06))
+	v14 ^= v02
+	v14 = v14>>32 | v14<<32
+	v10 += v14 + 2*uint64(uint32(v10))*uint64(uint32(v14))
+	v06 ^= v10
+	v06 = v06>>24 | v06<<40
+
+	v02 += v06 + 2*uint64(uint32(v02))*uint64(uint32(v06))
+	v14 ^= v02
+	v14 = v14>>16 | v14<<48
+	v10 += v14 + 2*uint64(uint32(v10))*uint64(uint32(v14))
+	v06 ^= v10
+	v06 = v06>>63 | v06<<1
+
+	v03 += v07 + 2*uint64(uint32(v03))*uint64(uint32(v07))
+	v15 ^= v03
+	v15 = v15>>32 | v15<<32
+	v11 += v15 + 2*uint64(uint32(v11))*uint64(uint32(v15))
+	v07 ^= v11
+	v07 = v07>>24 | v07<<40
+
+	v03 += v07 + 2*uint64(uint32(v03))*uint64(uint32(v07))
+	v15 ^= v03
+	v15 = v15>>16 | v15<<48
+	v11 += v15 + 2*uint64(uint32(v11))*uint64(uint32(v15))
+	v07 ^= v11
+	v07 = v07>>63 | v07<<1
+
+	v00 += v05 + 2*uint64(uint32(v00))*uint64(uint32(v05))
+	v15 ^= v00
+	v15 = v15>>32 | v15<<32
+	v10 += v15 + 2*uint64(uint32(v10))*uint64(uint32(v15))
+	v05 ^= v10
+	v05 = v05>>24 | v05<<40
+
+	v00 += v05 + 2*uint64(uint32(v00))*uint64(uint32(v05))
+	v15 ^= v00
+	v15 = v15>>16 | v15<<48
+	v10 += v15 + 2*uint64(uint32(v10))*uint64(uint32(v15))
+	v05 ^= v10
+	v05 = v05>>63 | v05<<1
+
+	v01 += v06 + 2*uint64(uint32(v01))*uint64(uint32(v06))
+	v12 ^= v01
+	v12 = v12>>32 | v12<<32
+	v11 += v12 + 2*uint64(uint32(v11))*uint64(uint32(v12))
+	v06 ^= v11
+	v06 = v06>>24 | v06<<40
+
+	v01 += v06 + 2*uint64(uint32(v01))*uint64(uint32(v06))
+	v12 ^= v01
+	v12 = v12>>16 | v12<<48
+	v11 += v12 + 2*uint64(uint32(v11))*uint64(uint32(v12))
+	v06 ^= v11
+	v06 = v06>>63 | v06<<1
+
+	v02 += v07 + 2*uint64(uint32(v02))*uint64(uint32(v07))
+	v13 ^= v02
+	v13 = v13>>32 | v13<<32
+	v08 += v13 + 2*uint64(uint32(v08))*uint64(uint32(v13))
+	v07 ^= v08
+	v07 = v07>>24 | v07<<40
+
+	v02 += v07 + 2*uint64(uint32(v02))*uint64(uint32(v07))
+	v13 ^= v02
+	v13 = v13>>16 | v13<<48
+	v08 += v13 + 2*uint64(uint32(v08))*uint64(uint32(v13))
+	v07 ^= v08
+	v07 = v07>>63 | v07<<1
+
+	v03 += v04 + 2*uint64(uint32(v03))*uint64(uint32(v04))
+	v14 ^= v03
+	v14 = v14>>32 | v14<<32
+	v09 += v14 + 2*uint64(uint32(v09))*uint64(uint32(v14))
+	v04 ^= v09
+	v04 = v04>>24 | v04<<40
+
+	v03 += v04 + 2*uint64(uint32(v03))*uint64(uint32(v04))
+	v14 ^= v03
+	v14 = v14>>16 | v14<<48
+	v09 += v14 + 2*uint64(uint32(v09))*uint64(uint32(v14))
+	v04 ^= v09
+	v04 = v04>>63 | v04<<1
+
+	*t00, *t01, *t02, *t03 = v00, v01, v02, v03
+	*t04, *t05, *t06, *t07 = v04, v05, v06, v07
+	*t08, *t09, *t10, *t11 = v08, v09, v10, v11
+	*t12, *t13, *t14, *t15 = v12, v13, v14, v15
+}
diff --git a/vendor/golang.org/x/crypto/argon2/blamka_ref.go b/vendor/golang.org/x/crypto/argon2/blamka_ref.go
new file mode 100644
index 0000000..baf7b55
--- /dev/null
+++ b/vendor/golang.org/x/crypto/argon2/blamka_ref.go
@@ -0,0 +1,15 @@
+// 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.
+
+// +build !amd64 appengine gccgo
+
+package argon2
+
+func processBlock(out, in1, in2 *block) {
+	processBlockGeneric(out, in1, in2, false)
+}
+
+func processBlockXOR(out, in1, in2 *block) {
+	processBlockGeneric(out, in1, in2, true)
+}
diff --git a/vendor/golang.org/x/crypto/blake2b/blake2b.go b/vendor/golang.org/x/crypto/blake2b/blake2b.go
index 7f0a86e..6dedb89 100644
--- a/vendor/golang.org/x/crypto/blake2b/blake2b.go
+++ b/vendor/golang.org/x/crypto/blake2b/blake2b.go
@@ -39,7 +39,10 @@ var (
 	useSSE4 bool
 )
 
-var errKeySize = errors.New("blake2b: invalid key size")
+var (
+	errKeySize  = errors.New("blake2b: invalid key size")
+	errHashSize = errors.New("blake2b: invalid hash size")
+)
 
 var iv = [8]uint64{
 	0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
@@ -83,7 +86,18 @@ func New384(key []byte) (hash.Hash, error) { return newDigest(Size384, key) }
 // key turns the hash into a MAC. The key must between zero and 64 bytes long.
 func New256(key []byte) (hash.Hash, error) { return newDigest(Size256, key) }
 
+// New returns a new hash.Hash computing the BLAKE2b checksum with a custom length.
+// A non-nil key turns the hash into a MAC. The key must between zero and 64 bytes long.
+// The hash size can be a value between 1 and 64 but it is highly recommended to use
+// values equal or greater than:
+// - 32 if BLAKE2b is used as a hash function (The key is zero bytes long).
+// - 16 if BLAKE2b is used as a MAC function (The key is at least 16 bytes long).
+func New(size int, key []byte) (hash.Hash, error) { return newDigest(size, key) }
+
 func newDigest(hashSize int, key []byte) (*digest, error) {
+	if hashSize < 1 || hashSize > Size {
+		return nil, errHashSize
+	}
 	if len(key) > Size {
 		return nil, errKeySize
 	}
diff --git a/vendor/golang.org/x/crypto/bn256/bn256.go b/vendor/golang.org/x/crypto/bn256/bn256.go
index ae232ac..f88f3fc 100644
--- a/vendor/golang.org/x/crypto/bn256/bn256.go
+++ b/vendor/golang.org/x/crypto/bn256/bn256.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package bn256 implements a particular bilinear group at the 128-bit security level.
+// Package bn256 implements a particular bilinear group.
 //
 // Bilinear groups are the basis of many of the new cryptographic protocols
 // that have been proposed over the past decade. They consist of a triplet of
@@ -14,6 +14,10 @@
 // Barreto-Naehrig curve as described in
 // http://cryptojedi.org/papers/dclxvi-20100714.pdf. Its output is compatible
 // with the implementation described in that paper.
+//
+// (This package previously claimed to operate at a 128-bit security level.
+// However, recent improvements in attacks mean that is no longer true. See
+// https://moderncrypto.org/mail-archive/curves/2016/000740.html.)
 package bn256 // import "golang.org/x/crypto/bn256"
 
 import (
diff --git a/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go b/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go
index f7e4bfb..4ac014f 100644
--- a/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go
+++ b/vendor/golang.org/x/crypto/chacha20poly1305/chacha20poly1305_generic.go
@@ -7,7 +7,7 @@ package chacha20poly1305
 import (
 	"encoding/binary"
 
-	"golang.org/x/crypto/chacha20poly1305/internal/chacha20"
+	"golang.org/x/crypto/internal/chacha20"
 	"golang.org/x/crypto/poly1305"
 )
 
diff --git a/vendor/golang.org/x/crypto/chacha20poly1305/internal/chacha20/chacha_generic.go b/vendor/golang.org/x/crypto/internal/chacha20/chacha_generic.go
index 0f8efdb..0f8efdb 100644
--- a/vendor/golang.org/x/crypto/chacha20poly1305/internal/chacha20/chacha_generic.go
+++ b/vendor/golang.org/x/crypto/internal/chacha20/chacha_generic.go
diff --git a/vendor/golang.org/x/crypto/chacha20poly1305/internal/chacha20/chacha_test.go b/vendor/golang.org/x/crypto/internal/chacha20/chacha_test.go
index b80d34c..b80d34c 100644
--- a/vendor/golang.org/x/crypto/chacha20poly1305/internal/chacha20/chacha_test.go
+++ b/vendor/golang.org/x/crypto/internal/chacha20/chacha_test.go
diff --git a/vendor/golang.org/x/crypto/pbkdf2/pbkdf2_test.go b/vendor/golang.org/x/crypto/pbkdf2/pbkdf2_test.go
index 1379240..f83cb69 100644
--- a/vendor/golang.org/x/crypto/pbkdf2/pbkdf2_test.go
+++ b/vendor/golang.org/x/crypto/pbkdf2/pbkdf2_test.go
@@ -155,3 +155,22 @@ func TestWithHMACSHA1(t *testing.T) {
 func TestWithHMACSHA256(t *testing.T) {
 	testHash(t, sha256.New, "SHA256", sha256TestVectors)
 }
+
+var sink uint8
+
+func benchmark(b *testing.B, h func() hash.Hash) {
+	password := make([]byte, h().Size())
+	salt := make([]byte, 8)
+	for i := 0; i < b.N; i++ {
+		password = Key(password, salt, 4096, len(password), h)
+	}
+	sink += password[0]
+}
+
+func BenchmarkHMACSHA1(b *testing.B) {
+	benchmark(b, sha1.New)
+}
+
+func BenchmarkHMACSHA256(b *testing.B) {
+	benchmark(b, sha256.New)
+}
diff --git a/vendor/golang.org/x/crypto/ssh/benchmark_test.go b/vendor/golang.org/x/crypto/ssh/benchmark_test.go
index d9f7eb9..20c3307 100644
--- a/vendor/golang.org/x/crypto/ssh/benchmark_test.go
+++ b/vendor/golang.org/x/crypto/ssh/benchmark_test.go
@@ -40,7 +40,8 @@ func sshPipe() (Conn, *server, error) {
 	}
 
 	clientConf := ClientConfig{
-		User: "user",
+		User:            "user",
+		HostKeyCallback: InsecureIgnoreHostKey(),
 	}
 	serverConf := ServerConfig{
 		NoClientAuth: true,
diff --git a/vendor/golang.org/x/crypto/ssh/certs.go b/vendor/golang.org/x/crypto/ssh/certs.go
index 5c9fadc..cfc8ead 100644
--- a/vendor/golang.org/x/crypto/ssh/certs.go
+++ b/vendor/golang.org/x/crypto/ssh/certs.go
@@ -340,7 +340,7 @@ 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/certs_test.go b/vendor/golang.org/x/crypto/ssh/certs_test.go
index 0200531..c8e7cf5 100644
--- a/vendor/golang.org/x/crypto/ssh/certs_test.go
+++ b/vendor/golang.org/x/crypto/ssh/certs_test.go
@@ -6,10 +6,15 @@ package ssh
 
 import (
 	"bytes"
+	"crypto/ecdsa"
+	"crypto/elliptic"
 	"crypto/rand"
+	"net"
 	"reflect"
 	"testing"
 	"time"
+
+	"golang.org/x/crypto/ssh/testdata"
 )
 
 // Cert generated by ssh-keygen 6.0p1 Debian-4.
@@ -220,3 +225,111 @@ func TestHostKeyCert(t *testing.T) {
 		}
 	}
 }
+
+func TestCertTypes(t *testing.T) {
+	var testVars = []struct {
+		name string
+		keys func() Signer
+	}{
+		{
+			name: CertAlgoECDSA256v01,
+			keys: func() Signer {
+				s, _ := ParsePrivateKey(testdata.PEMBytes["ecdsap256"])
+				return s
+			},
+		},
+		{
+			name: CertAlgoECDSA384v01,
+			keys: func() Signer {
+				s, _ := ParsePrivateKey(testdata.PEMBytes["ecdsap384"])
+				return s
+			},
+		},
+		{
+			name: CertAlgoECDSA521v01,
+			keys: func() Signer {
+				s, _ := ParsePrivateKey(testdata.PEMBytes["ecdsap521"])
+				return s
+			},
+		},
+		{
+			name: CertAlgoED25519v01,
+			keys: func() Signer {
+				s, _ := ParsePrivateKey(testdata.PEMBytes["ed25519"])
+				return s
+			},
+		},
+		{
+			name: CertAlgoRSAv01,
+			keys: func() Signer {
+				s, _ := ParsePrivateKey(testdata.PEMBytes["rsa"])
+				return s
+			},
+		},
+		{
+			name: CertAlgoDSAv01,
+			keys: func() Signer {
+				s, _ := ParsePrivateKey(testdata.PEMBytes["dsa"])
+				return s
+			},
+		},
+	}
+
+	k, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatalf("error generating host key: %v", err)
+	}
+
+	signer, err := NewSignerFromKey(k)
+	if err != nil {
+		t.Fatalf("error generating signer for ssh listener: %v", err)
+	}
+
+	conf := &ServerConfig{
+		PublicKeyCallback: func(c ConnMetadata, k PublicKey) (*Permissions, error) {
+			return new(Permissions), nil
+		},
+	}
+	conf.AddHostKey(signer)
+
+	for _, m := range testVars {
+		t.Run(m.name, func(t *testing.T) {
+
+			c1, c2, err := netPipe()
+			if err != nil {
+				t.Fatalf("netPipe: %v", err)
+			}
+			defer c1.Close()
+			defer c2.Close()
+
+			go NewServerConn(c1, conf)
+
+			priv := m.keys()
+			if err != nil {
+				t.Fatalf("error generating ssh pubkey: %v", err)
+			}
+
+			cert := &Certificate{
+				CertType: UserCert,
+				Key:      priv.PublicKey(),
+			}
+			cert.SignCert(rand.Reader, priv)
+
+			certSigner, err := NewCertSigner(cert, priv)
+			if err != nil {
+				t.Fatalf("error generating cert signer: %v", err)
+			}
+
+			config := &ClientConfig{
+				User:            "user",
+				HostKeyCallback: func(h string, r net.Addr, k PublicKey) error { return nil },
+				Auth:            []AuthMethod{PublicKeys(certSigner)},
+			}
+
+			_, _, _, err = NewClientConn(c2, "", config)
+			if err != nil {
+				t.Fatalf("error connecting: %v", err)
+			}
+		})
+	}
+}
diff --git a/vendor/golang.org/x/crypto/ssh/cipher.go b/vendor/golang.org/x/crypto/ssh/cipher.go
index e67c5e0..30a49fd 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/cipher_test.go b/vendor/golang.org/x/crypto/ssh/cipher_test.go
index 5cfa17a..a52d6e4 100644
--- a/vendor/golang.org/x/crypto/ssh/cipher_test.go
+++ b/vendor/golang.org/x/crypto/ssh/cipher_test.go
@@ -7,7 +7,6 @@ package ssh
 import (
 	"bytes"
 	"crypto"
-	"crypto/aes"
 	"crypto/rand"
 	"testing"
 )
@@ -15,60 +14,63 @@ import (
 func TestDefaultCiphersExist(t *testing.T) {
 	for _, cipherAlgo := range supportedCiphers {
 		if _, ok := cipherModes[cipherAlgo]; !ok {
-			t.Errorf("default cipher %q is unknown", cipherAlgo)
+			t.Errorf("supported cipher %q is unknown", cipherAlgo)
+		}
+	}
+	for _, cipherAlgo := range preferredCiphers {
+		if _, ok := cipherModes[cipherAlgo]; !ok {
+			t.Errorf("preferred cipher %q is unknown", cipherAlgo)
 		}
 	}
 }
 
 func TestPacketCiphers(t *testing.T) {
-	// Still test aes128cbc cipher although it's commented out.
-	cipherModes[aes128cbcID] = &streamCipherMode{16, aes.BlockSize, 0, nil}
-	defer delete(cipherModes, aes128cbcID)
-
+	defaultMac := "hmac-sha2-256"
+	defaultCipher := "aes128-ctr"
 	for cipher := range cipherModes {
-		for mac := range macModes {
-			kr := &kexResult{Hash: crypto.SHA1}
-			algs := directionAlgorithms{
-				Cipher:      cipher,
-				MAC:         mac,
-				Compression: "none",
-			}
-			client, err := newPacketCipher(clientKeys, algs, kr)
-			if err != nil {
-				t.Errorf("newPacketCipher(client, %q, %q): %v", cipher, mac, err)
-				continue
-			}
-			server, err := newPacketCipher(clientKeys, algs, kr)
-			if err != nil {
-				t.Errorf("newPacketCipher(client, %q, %q): %v", cipher, mac, err)
-				continue
-			}
-
-			want := "bla bla"
-			input := []byte(want)
-			buf := &bytes.Buffer{}
-			if err := client.writePacket(0, buf, rand.Reader, input); err != nil {
-				t.Errorf("writePacket(%q, %q): %v", cipher, mac, err)
-				continue
-			}
-
-			packet, err := server.readPacket(0, buf)
-			if err != nil {
-				t.Errorf("readPacket(%q, %q): %v", cipher, mac, err)
-				continue
-			}
-
-			if string(packet) != want {
-				t.Errorf("roundtrip(%q, %q): got %q, want %q", cipher, mac, packet, want)
-			}
-		}
+		t.Run("cipher="+cipher,
+			func(t *testing.T) { testPacketCipher(t, cipher, defaultMac) })
+	}
+	for mac := range macModes {
+		t.Run("mac="+mac,
+			func(t *testing.T) { testPacketCipher(t, defaultCipher, mac) })
 	}
 }
 
-func TestCBCOracleCounterMeasure(t *testing.T) {
-	cipherModes[aes128cbcID] = &streamCipherMode{16, aes.BlockSize, 0, nil}
-	defer delete(cipherModes, aes128cbcID)
+func testPacketCipher(t *testing.T, cipher, mac string) {
+	kr := &kexResult{Hash: crypto.SHA1}
+	algs := directionAlgorithms{
+		Cipher:      cipher,
+		MAC:         mac,
+		Compression: "none",
+	}
+	client, err := newPacketCipher(clientKeys, algs, kr)
+	if err != nil {
+		t.Fatalf("newPacketCipher(client, %q, %q): %v", cipher, mac, err)
+	}
+	server, err := newPacketCipher(clientKeys, algs, kr)
+	if err != nil {
+		t.Fatalf("newPacketCipher(client, %q, %q): %v", cipher, mac, err)
+	}
+
+	want := "bla bla"
+	input := []byte(want)
+	buf := &bytes.Buffer{}
+	if err := client.writePacket(0, buf, rand.Reader, input); err != nil {
+		t.Fatalf("writePacket(%q, %q): %v", cipher, mac, err)
+	}
 
+	packet, err := server.readPacket(0, buf)
+	if err != nil {
+		t.Fatalf("readPacket(%q, %q): %v", cipher, mac, err)
+	}
+
+	if string(packet) != want {
+		t.Errorf("roundtrip(%q, %q): got %q, want %q", cipher, mac, packet, want)
+	}
+}
+
+func TestCBCOracleCounterMeasure(t *testing.T) {
 	kr := &kexResult{Hash: crypto.SHA1}
 	algs := directionAlgorithms{
 		Cipher:      aes128cbcID,
diff --git a/vendor/golang.org/x/crypto/ssh/client_test.go b/vendor/golang.org/x/crypto/ssh/client_test.go
index ef95069..81f9599 100644
--- a/vendor/golang.org/x/crypto/ssh/client_test.go
+++ b/vendor/golang.org/x/crypto/ssh/client_test.go
@@ -5,41 +5,77 @@
 package ssh
 
 import (
-	"net"
 	"strings"
 	"testing"
 )
 
-func testClientVersion(t *testing.T, config *ClientConfig, expected string) {
-	clientConn, serverConn := net.Pipe()
-	defer clientConn.Close()
-	receivedVersion := make(chan string, 1)
-	config.HostKeyCallback = InsecureIgnoreHostKey()
-	go func() {
-		version, err := readVersion(serverConn)
-		if err != nil {
-			receivedVersion <- ""
-		} else {
-			receivedVersion <- string(version)
-		}
-		serverConn.Close()
-	}()
-	NewClientConn(clientConn, "", config)
-	actual := <-receivedVersion
-	if actual != expected {
-		t.Fatalf("got %s; want %s", actual, expected)
+func TestClientVersion(t *testing.T) {
+	for _, tt := range []struct {
+		name      string
+		version   string
+		multiLine string
+		wantErr   bool
+	}{
+		{
+			name:    "default version",
+			version: packageVersion,
+		},
+		{
+			name:    "custom version",
+			version: "SSH-2.0-CustomClientVersionString",
+		},
+		{
+			name:      "good multi line version",
+			version:   packageVersion,
+			multiLine: strings.Repeat("ignored\r\n", 20),
+		},
+		{
+			name:      "bad multi line version",
+			version:   packageVersion,
+			multiLine: "bad multi line version",
+			wantErr:   true,
+		},
+		{
+			name:      "long multi line version",
+			version:   packageVersion,
+			multiLine: strings.Repeat("long multi line version\r\n", 50)[:256],
+			wantErr:   true,
+		},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			c1, c2, err := netPipe()
+			if err != nil {
+				t.Fatalf("netPipe: %v", err)
+			}
+			defer c1.Close()
+			defer c2.Close()
+			go func() {
+				if tt.multiLine != "" {
+					c1.Write([]byte(tt.multiLine))
+				}
+				NewClientConn(c1, "", &ClientConfig{
+					ClientVersion:   tt.version,
+					HostKeyCallback: InsecureIgnoreHostKey(),
+				})
+				c1.Close()
+			}()
+			conf := &ServerConfig{NoClientAuth: true}
+			conf.AddHostKey(testSigners["rsa"])
+			conn, _, _, err := NewServerConn(c2, conf)
+			if err == nil == tt.wantErr {
+				t.Fatalf("got err %v; wantErr %t", err, tt.wantErr)
+			}
+			if tt.wantErr {
+				// Don't verify the version on an expected error.
+				return
+			}
+			if got := string(conn.ClientVersion()); got != tt.version {
+				t.Fatalf("got %q; want %q", got, tt.version)
+			}
+		})
 	}
 }
 
-func TestCustomClientVersion(t *testing.T) {
-	version := "Test-Client-Version-0.0"
-	testClientVersion(t, &ClientConfig{ClientVersion: version}, version)
-}
-
-func TestDefaultClientVersion(t *testing.T) {
-	testClientVersion(t, &ClientConfig{}, packageVersion)
-}
-
 func TestHostKeyCheck(t *testing.T) {
 	for _, tt := range []struct {
 		name      string
diff --git a/vendor/golang.org/x/crypto/ssh/common.go b/vendor/golang.org/x/crypto/ssh/common.go
index 135b4ed..04f3620 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/knownhosts/knownhosts.go b/vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go
index 448fc07..46dad14 100644
--- 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 {
diff --git a/vendor/golang.org/x/crypto/ssh/server.go b/vendor/golang.org/x/crypto/ssh/server.go
index d4df916..b83d473 100644
--- a/vendor/golang.org/x/crypto/ssh/server.go
+++ b/vendor/golang.org/x/crypto/ssh/server.go
@@ -256,7 +256,7 @@ 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
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 92944f3..4933ac3 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/session_test.go b/vendor/golang.org/x/crypto/ssh/test/session_test.go
index 8238d9d..4eb7afd 100644
--- a/vendor/golang.org/x/crypto/ssh/test/session_test.go
+++ b/vendor/golang.org/x/crypto/ssh/test/session_test.go
@@ -11,6 +11,7 @@ package test
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"io"
 	"strings"
 	"testing"
@@ -324,27 +325,56 @@ func TestWindowChange(t *testing.T) {
 	}
 }
 
+func testOneCipher(t *testing.T, cipher string, cipherOrder []string) {
+	server := newServer(t)
+	defer server.Shutdown()
+	conf := clientConfig()
+	conf.Ciphers = []string{cipher}
+	// Don't fail if sshd doesn't have the cipher.
+	conf.Ciphers = append(conf.Ciphers, cipherOrder...)
+	conn, err := server.TryDial(conf)
+	if err != nil {
+		t.Fatalf("TryDial: %v", err)
+	}
+	defer conn.Close()
+
+	numBytes := 4096
+
+	// Exercise sending data to the server
+	if _, _, err := conn.Conn.SendRequest("drop-me", false, make([]byte, numBytes)); err != nil {
+		t.Fatalf("SendRequest: %v", err)
+	}
+
+	// Exercise receiving data from the server
+	session, err := conn.NewSession()
+	if err != nil {
+		t.Fatalf("NewSession: %v", err)
+	}
+
+	out, err := session.Output(fmt.Sprintf("dd if=/dev/zero of=/dev/stdout bs=%d count=1", numBytes))
+	if err != nil {
+		t.Fatalf("Output: %v", err)
+	}
+
+	if len(out) != numBytes {
+		t.Fatalf("got %d bytes, want %d bytes", len(out), numBytes)
+	}
+}
+
+var deprecatedCiphers = []string{
+	"aes128-cbc", "3des-cbc",
+	"arcfour128", "arcfour256",
+}
+
 func TestCiphers(t *testing.T) {
 	var config ssh.Config
 	config.SetDefaults()
-	cipherOrder := config.Ciphers
-	// These ciphers will not be tested when commented out in cipher.go it will
-	// fallback to the next available as per line 292.
-	cipherOrder = append(cipherOrder, "aes128-cbc", "3des-cbc")
+	cipherOrder := append(config.Ciphers, deprecatedCiphers...)
 
 	for _, ciph := range cipherOrder {
-		server := newServer(t)
-		defer server.Shutdown()
-		conf := clientConfig()
-		conf.Ciphers = []string{ciph}
-		// Don't fail if sshd doesn't have the cipher.
-		conf.Ciphers = append(conf.Ciphers, cipherOrder...)
-		conn, err := server.TryDial(conf)
-		if err == nil {
-			conn.Close()
-		} else {
-			t.Fatalf("failed for cipher %q", ciph)
-		}
+		t.Run(ciph, func(t *testing.T) {
+			testOneCipher(t, ciph, cipherOrder)
+		})
 	}
 }
 
diff --git a/vendor/golang.org/x/crypto/ssh/testdata/keys.go b/vendor/golang.org/x/crypto/ssh/testdata/keys.go
index 3b3d26c..521b6be 100644
--- a/vendor/golang.org/x/crypto/ssh/testdata/keys.go
+++ b/vendor/golang.org/x/crypto/ssh/testdata/keys.go
@@ -24,6 +24,27 @@ AwEHoUQDQgAEi9Hdw6KvZcWxfg2IDhA7UkpDtzzt6ZqJXSsFdLd+Kx4S3Sx4cVO+
 6/ZOXRnPmNAlLUqjShUsUBBngG0u2fqEqA==
 -----END EC PRIVATE KEY-----
 `),
+	"ecdsap256": []byte(`-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIAPCE25zK0PQSnsgVcEbM1mbKTASH4pqb5QJajplDwDZoAoGCCqGSM49
+AwEHoUQDQgAEWy8TxGcIHRh5XGpO4dFVfDjeNY+VkgubQrf/eyFJZHxAn1SKraXU
+qJUjTKj1z622OxYtJ5P7s9CfAEVsTzLCzg==
+-----END EC PRIVATE KEY-----
+`),
+	"ecdsap384": []byte(`-----BEGIN EC PRIVATE KEY-----
+MIGkAgEBBDBWfSnMuNKq8J9rQLzzEkx3KAoEohSXqhE/4CdjEYtoU2i22HW80DDS
+qQhYNHRAduygBwYFK4EEACKhZANiAAQWaDMAd0HUd8ZiXCX7mYDDnC54gwH/nG43
+VhCUEYmF7HMZm/B9Yn3GjFk3qYEDEvuF/52+NvUKBKKaLbh32AWxMv0ibcoba4cz
+hL9+hWYhUD9XIUlzMWiZ2y6eBE9PdRI=
+-----END EC PRIVATE KEY-----
+`),
+	"ecdsap521": []byte(`-----BEGIN EC PRIVATE KEY-----
+MIHcAgEBBEIBrkYpQcy8KTVHNiAkjlFZwee90224Bu6wz94R4OBo+Ts0eoAQG7SF
+iaygEDMUbx6kTgXTBcKZ0jrWPKakayNZ/kigBwYFK4EEACOhgYkDgYYABADFuvLV
+UoaCDGHcw5uNfdRIsvaLKuWSpLsl48eWGZAwdNG432GDVKduO+pceuE+8XzcyJb+
+uMv+D2b11Q/LQUcHJwE6fqbm8m3EtDKPsoKs0u/XUJb0JsH4J8lkZzbUTjvGYamn
+FFlRjzoB3Oxu8UQgb+MWPedtH9XYBbg9biz4jJLkXQ==
+-----END EC PRIVATE KEY-----
+`),
 	"rsa": []byte(`-----BEGIN RSA PRIVATE KEY-----
 MIICXAIBAAKBgQC8A6FGHDiWCSREAXCq6yBfNVr0xCVG2CzvktFNRpue+RXrGs/2
 a6ySEJQb3IYquw7HlJgu6fg3WIWhOmHCjfpG0PrL4CRwbqQ2LaPPXhJErWYejcD8
diff --git a/vendor/golang.org/x/crypto/ssh/transport.go b/vendor/golang.org/x/crypto/ssh/transport.go
index 01150eb..f6fae1d 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
 		}
diff --git a/vendor/golang.org/x/crypto/ssh/transport_test.go b/vendor/golang.org/x/crypto/ssh/transport_test.go
index 92d83ab..8445e1e 100644
--- a/vendor/golang.org/x/crypto/ssh/transport_test.go
+++ b/vendor/golang.org/x/crypto/ssh/transport_test.go
@@ -13,11 +13,13 @@ import (
 )
 
 func TestReadVersion(t *testing.T) {
-	longversion := strings.Repeat("SSH-2.0-bla", 50)[:253]
+	longVersion := strings.Repeat("SSH-2.0-bla", 50)[:253]
+	multiLineVersion := strings.Repeat("ignored\r\n", 20) + "SSH-2.0-bla\r\n"
 	cases := map[string]string{
 		"SSH-2.0-bla\r\n":    "SSH-2.0-bla",
 		"SSH-2.0-bla\n":      "SSH-2.0-bla",
-		longversion + "\r\n": longversion,
+		multiLineVersion:     "SSH-2.0-bla",
+		longVersion + "\r\n": longVersion,
 	}
 
 	for in, want := range cases {
@@ -33,9 +35,11 @@ func TestReadVersion(t *testing.T) {
 }
 
 func TestReadVersionError(t *testing.T) {
-	longversion := strings.Repeat("SSH-2.0-bla", 50)[:253]
+	longVersion := strings.Repeat("SSH-2.0-bla", 50)[:253]
+	multiLineVersion := strings.Repeat("ignored\r\n", 50) + "SSH-2.0-bla\r\n"
 	cases := []string{
-		longversion + "too-long\r\n",
+		longVersion + "too-long\r\n",
+		multiLineVersion,
 	}
 	for _, in := range cases {
 		if _, err := readVersion(bytes.NewBufferString(in)); err == nil {
@@ -60,7 +64,7 @@ func TestExchangeVersionsBasic(t *testing.T) {
 func TestExchangeVersions(t *testing.T) {
 	cases := []string{
 		"not\x000allowed",
-		"not allowed\n",
+		"not allowed\x01\r\n",
 	}
 	for _, c := range cases {
 		buf := bytes.NewBufferString("SSH-2.0-bla\r\n")