Update vendor dependencies

vendor/golang.org/x/crypto/ssh/agent/client.go

@@ -8,7 +8,7 @@
 // ssh-agent process using the sample server.
 //
 // References:
-//  [PROTOCOL.agent]:    http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ssh/PROTOCOL.agent?rev=HEAD
+//  [PROTOCOL.agent]: https://tools.ietf.org/html/draft-miller-ssh-agent-00
 package agent // import "golang.org/x/crypto/ssh/agent"
 
 import (

vendor/golang.org/x/crypto/ssh/agent/keyring.go

@@ -102,7 +102,7 @@ func (r *keyring) Unlock(passphrase []byte) error {
 	if !r.locked {
 		return errors.New("agent: not locked")
 	}
-	if len(passphrase) != len(r.passphrase) || 1 != subtle.ConstantTimeCompare(passphrase, r.passphrase) {
+	if 1 != subtle.ConstantTimeCompare(passphrase, r.passphrase) {
 		return fmt.Errorf("agent: incorrect passphrase")
 	}
 

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

vendor/golang.org/x/crypto/ssh/cipher.go

@@ -16,6 +16,7 @@ import (
 	"hash"
 	"io"
 	"io/ioutil"
+	"math/bits"
 
 	"golang.org/x/crypto/internal/chacha20"
 	"golang.org/x/crypto/poly1305"
@@ -641,8 +642,8 @@ const chacha20Poly1305ID = "chacha20-poly1305@openssh.com"
 // the methods here also implement padding, which RFC4253 Section 6
 // also requires of stream ciphers.
 type chacha20Poly1305Cipher struct {
-	lengthKey  [32]byte
-	contentKey [32]byte
+	lengthKey  [8]uint32
+	contentKey [8]uint32
 	buf        []byte
 }
 
@@ -655,20 +656,21 @@ func newChaCha20Cipher(key, unusedIV, unusedMACKey []byte, unusedAlgs directionA
 		buf: make([]byte, 256),
 	}
 
-	copy(c.contentKey[:], key[:32])
-	copy(c.lengthKey[:], key[32:])
+	for i := range c.contentKey {
+		c.contentKey[i] = binary.LittleEndian.Uint32(key[i*4 : (i+1)*4])
+	}
+	for i := range c.lengthKey {
+		c.lengthKey[i] = binary.LittleEndian.Uint32(key[(i+8)*4 : (i+9)*4])
+	}
 	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))
-
+	nonce := [3]uint32{0, 0, bits.ReverseBytes32(seqNum)}
+	s := chacha20.New(c.contentKey, nonce)
 	var polyKey [32]byte
-	chacha20.XORKeyStream(polyKey[:], chacha20PolyKeyInput[:], &counter, &c.contentKey)
+	s.XORKeyStream(polyKey[:], polyKey[:])
+	s.Advance() // skip next 32 bytes
 
 	encryptedLength := c.buf[:4]
 	if _, err := io.ReadFull(r, encryptedLength); err != nil {
@@ -676,7 +678,7 @@ func (c *chacha20Poly1305Cipher) readPacket(seqNum uint32, r io.Reader) ([]byte,
 	}
 
 	var lenBytes [4]byte
-	chacha20.XORKeyStream(lenBytes[:], encryptedLength, &counter, &c.lengthKey)
+	chacha20.New(c.lengthKey, nonce).XORKeyStream(lenBytes[:], encryptedLength)
 
 	length := binary.BigEndian.Uint32(lenBytes[:])
 	if length > maxPacket {
@@ -702,10 +704,8 @@ func (c *chacha20Poly1305Cipher) readPacket(seqNum uint32, r io.Reader) ([]byte,
 		return nil, errors.New("ssh: MAC failure")
 	}
 
-	counter[0] = 1
-
 	plain := c.buf[4:contentEnd]
-	chacha20.XORKeyStream(plain, plain, &counter, &c.contentKey)
+	s.XORKeyStream(plain, plain)
 
 	padding := plain[0]
 	if padding < 4 {
@@ -724,11 +724,11 @@ func (c *chacha20Poly1305Cipher) readPacket(seqNum uint32, r io.Reader) ([]byte,
 }
 
 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))
-
+	nonce := [3]uint32{0, 0, bits.ReverseBytes32(seqNum)}
+	s := chacha20.New(c.contentKey, nonce)
 	var polyKey [32]byte
-	chacha20.XORKeyStream(polyKey[:], chacha20PolyKeyInput[:], &counter, &c.contentKey)
+	s.XORKeyStream(polyKey[:], polyKey[:])
+	s.Advance() // skip next 32 bytes
 
 	// There is no blocksize, so fall back to multiple of 8 byte
 	// padding, as described in RFC 4253, Sec 6.
@@ -748,7 +748,7 @@ func (c *chacha20Poly1305Cipher) writePacket(seqNum uint32, w io.Writer, rand io
 	}
 
 	binary.BigEndian.PutUint32(c.buf, uint32(1+len(payload)+padding))
-	chacha20.XORKeyStream(c.buf, c.buf[:4], &counter, &c.lengthKey)
+	chacha20.New(c.lengthKey, nonce).XORKeyStream(c.buf, c.buf[:4])
 	c.buf[4] = byte(padding)
 	copy(c.buf[5:], payload)
 	packetEnd := 5 + len(payload) + padding
@@ -756,8 +756,7 @@ func (c *chacha20Poly1305Cipher) writePacket(seqNum uint32, w io.Writer, rand io
 		return err
 	}
 
-	counter[0] = 1
-	chacha20.XORKeyStream(c.buf[4:], c.buf[4:packetEnd], &counter, &c.contentKey)
+	s.XORKeyStream(c.buf[4:], c.buf[4:packetEnd])
 
 	var mac [poly1305.TagSize]byte
 	poly1305.Sum(&mac, c.buf[:packetEnd], &polyKey)

vendor/golang.org/x/crypto/ssh/client.go

@@ -19,6 +19,8 @@ import (
 type Client struct {
 	Conn
 
+	handleForwardsOnce sync.Once // guards calling (*Client).handleForwards
+
 	forwards        forwardList // forwarded tcpip connections from the remote side
 	mu              sync.Mutex
 	channelHandlers map[string]chan NewChannel
@@ -60,8 +62,6 @@ func NewClient(c Conn, chans <-chan NewChannel, reqs <-chan *Request) *Client {
 		conn.Wait()
 		conn.forwards.closeAll()
 	}()
-	go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-tcpip"))
-	go conn.forwards.handleChannels(conn.HandleChannelOpen("forwarded-streamlocal@openssh.com"))
 	return conn
 }
 

vendor/golang.org/x/crypto/ssh/client_auth.go

@@ -11,6 +11,14 @@ import (
 	"io"
 )
 
+type authResult int
+
+const (
+	authFailure authResult = iota
+	authPartialSuccess
+	authSuccess
+)
+
 // clientAuthenticate authenticates with the remote server. See RFC 4252.
 func (c *connection) clientAuthenticate(config *ClientConfig) error {
 	// initiate user auth session
@@ -37,11 +45,12 @@ func (c *connection) clientAuthenticate(config *ClientConfig) error {
 		if err != nil {
 			return err
 		}
-		if ok {
+		if ok == authSuccess {
 			// success
 			return nil
+		} else if ok == authFailure {
+			tried[auth.method()] = true
 		}
-		tried[auth.method()] = true
 		if methods == nil {
 			methods = lastMethods
 		}
@@ -82,7 +91,7 @@ type AuthMethod interface {
 	// If authentication is not successful, a []string of alternative
 	// method names is returned. If the slice is nil, it will be ignored
 	// and the previous set of possible methods will be reused.
-	auth(session []byte, user string, p packetConn, rand io.Reader) (bool, []string, error)
+	auth(session []byte, user string, p packetConn, rand io.Reader) (authResult, []string, error)
 
 	// method returns the RFC 4252 method name.
 	method() string
@@ -91,13 +100,13 @@ type AuthMethod interface {
 // "none" authentication, RFC 4252 section 5.2.
 type noneAuth int
 
-func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+func (n *noneAuth) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	if err := c.writePacket(Marshal(&userAuthRequestMsg{
 		User:    user,
 		Service: serviceSSH,
 		Method:  "none",
 	})); err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	return handleAuthResponse(c)
@@ -111,7 +120,7 @@ func (n *noneAuth) method() string {
 // a function call, e.g. by prompting the user.
 type passwordCallback func() (password string, err error)
 
-func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	type passwordAuthMsg struct {
 		User     string `sshtype:"50"`
 		Service  string
@@ -125,7 +134,7 @@ func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand
 	// The program may only find out that the user doesn't have a password
 	// when prompting.
 	if err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	if err := c.writePacket(Marshal(&passwordAuthMsg{
@@ -135,7 +144,7 @@ func (cb passwordCallback) auth(session []byte, user string, c packetConn, rand
 		Reply:    false,
 		Password: pw,
 	})); err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	return handleAuthResponse(c)
@@ -178,7 +187,7 @@ func (cb publicKeyCallback) method() string {
 	return "publickey"
 }
 
-func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	// Authentication is performed by sending an enquiry to test if a key is
 	// acceptable to the remote. If the key is acceptable, the client will
 	// attempt to authenticate with the valid key.  If not the client will repeat
@@ -186,13 +195,13 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 
 	signers, err := cb()
 	if err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 	var methods []string
 	for _, signer := range signers {
 		ok, err := validateKey(signer.PublicKey(), user, c)
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 		if !ok {
 			continue
@@ -206,7 +215,7 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 			Method:  cb.method(),
 		}, []byte(pub.Type()), pubKey))
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// manually wrap the serialized signature in a string
@@ -224,24 +233,24 @@ func (cb publicKeyCallback) auth(session []byte, user string, c packetConn, rand
 		}
 		p := Marshal(&msg)
 		if err := c.writePacket(p); err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
-		var success bool
+		var success authResult
 		success, methods, err = handleAuthResponse(c)
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// If authentication succeeds or the list of available methods does not
 		// contain the "publickey" method, do not attempt to authenticate with any
 		// other keys.  According to RFC 4252 Section 7, the latter can occur when
 		// additional authentication methods are required.
-		if success || !containsMethod(methods, cb.method()) {
+		if success == authSuccess || !containsMethod(methods, cb.method()) {
 			return success, methods, err
 		}
 	}
 
-	return false, methods, nil
+	return authFailure, methods, nil
 }
 
 func containsMethod(methods []string, method string) bool {
@@ -318,28 +327,31 @@ func PublicKeysCallback(getSigners func() (signers []Signer, err error)) AuthMet
 // handleAuthResponse returns whether the preceding authentication request succeeded
 // along with a list of remaining authentication methods to try next and
 // an error if an unexpected response was received.
-func handleAuthResponse(c packetConn) (bool, []string, error) {
+func handleAuthResponse(c packetConn) (authResult, []string, error) {
 	for {
 		packet, err := c.readPacket()
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		switch packet[0] {
 		case msgUserAuthBanner:
 			if err := handleBannerResponse(c, packet); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
 		case msgUserAuthFailure:
 			var msg userAuthFailureMsg
 			if err := Unmarshal(packet, &msg); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
-			return false, msg.Methods, nil
+			if msg.PartialSuccess {
+				return authPartialSuccess, msg.Methods, nil
+			}
+			return authFailure, msg.Methods, nil
 		case msgUserAuthSuccess:
-			return true, nil, nil
+			return authSuccess, nil, nil
 		default:
-			return false, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
+			return authFailure, nil, unexpectedMessageError(msgUserAuthSuccess, packet[0])
 		}
 	}
 }
@@ -381,7 +393,7 @@ func (cb KeyboardInteractiveChallenge) method() string {
 	return "keyboard-interactive"
 }
 
-func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (bool, []string, error) {
+func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packetConn, rand io.Reader) (authResult, []string, error) {
 	type initiateMsg struct {
 		User       string `sshtype:"50"`
 		Service    string
@@ -395,20 +407,20 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		Service: serviceSSH,
 		Method:  "keyboard-interactive",
 	})); err != nil {
-		return false, nil, err
+		return authFailure, nil, err
 	}
 
 	for {
 		packet, err := c.readPacket()
 		if err != nil {
-			return false, nil, err
+			return authFailure, nil, err
 		}
 
 		// like handleAuthResponse, but with less options.
 		switch packet[0] {
 		case msgUserAuthBanner:
 			if err := handleBannerResponse(c, packet); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
 			continue
 		case msgUserAuthInfoRequest:
@@ -416,18 +428,21 @@ func (cb KeyboardInteractiveChallenge) auth(session []byte, user string, c packe
 		case msgUserAuthFailure:
 			var msg userAuthFailureMsg
 			if err := Unmarshal(packet, &msg); err != nil {
-				return false, nil, err
+				return authFailure, nil, err
 			}
-			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
 		}
 	}

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 {

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

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},
 	})
 }

vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts.go

@@ -2,8 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// Package knownhosts implements a parser for the OpenSSH
-// known_hosts host key database.
+// Package knownhosts implements a parser for the OpenSSH known_hosts
+// host key database, and provides utility functions for writing
+// OpenSSH compliant known_hosts files.
 package knownhosts
 
 import (
@@ -38,7 +39,7 @@ func (a *addr) String() string {
 }
 
 type matcher interface {
-	match([]addr) bool
+	match(addr) bool
 }
 
 type hostPattern struct {
@@ -57,19 +58,16 @@ func (p *hostPattern) String() string {
 
 type hostPatterns []hostPattern
 
-func (ps hostPatterns) match(addrs []addr) bool {
+func (ps hostPatterns) match(a addr) bool {
 	matched := false
 	for _, p := range ps {
-		for _, a := range addrs {
-			m := p.match(a)
-			if !m {
-				continue
-			}
-			if p.negate {
-				return false
-			}
-			matched = true
+		if !p.match(a) {
+			continue
 		}
+		if p.negate {
+			return false
+		}
+		matched = true
 	}
 	return matched
 }
@@ -122,8 +120,8 @@ func serialize(k ssh.PublicKey) string {
 	return k.Type() + " " + base64.StdEncoding.EncodeToString(k.Marshal())
 }
 
-func (l *keyDBLine) match(addrs []addr) bool {
-	return l.matcher.match(addrs)
+func (l *keyDBLine) match(a addr) bool {
+	return l.matcher.match(a)
 }
 
 type hostKeyDB struct {
@@ -153,7 +151,7 @@ func (db *hostKeyDB) IsHostAuthority(remote ssh.PublicKey, address string) bool
 	a := addr{host: h, port: p}
 
 	for _, l := range db.lines {
-		if l.cert && keyEq(l.knownKey.Key, remote) && l.match([]addr{a}) {
+		if l.cert && keyEq(l.knownKey.Key, remote) && l.match(a) {
 			return true
 		}
 	}
@@ -338,26 +336,24 @@ func (db *hostKeyDB) check(address string, remote net.Addr, remoteKey ssh.Public
 		return fmt.Errorf("knownhosts: SplitHostPort(%s): %v", remote, err)
 	}
 
-	addrs := []addr{
-		{host, port},
-	}
-
+	hostToCheck := addr{host, port}
 	if address != "" {
+		// Give preference to the hostname if available.
 		host, port, err := net.SplitHostPort(address)
 		if err != nil {
 			return fmt.Errorf("knownhosts: SplitHostPort(%s): %v", address, err)
 		}
 
-		addrs = append(addrs, addr{host, port})
+		hostToCheck = addr{host, port}
 	}
 
-	return db.checkAddrs(addrs, remoteKey)
+	return db.checkAddr(hostToCheck, remoteKey)
 }
 
 // checkAddrs checks if we can find the given public key for any of
 // the given addresses.  If we only find an entry for the IP address,
 // or only the hostname, then this still succeeds.
-func (db *hostKeyDB) checkAddrs(addrs []addr, remoteKey ssh.PublicKey) error {
+func (db *hostKeyDB) checkAddr(a addr, remoteKey ssh.PublicKey) error {
 	// TODO(hanwen): are these the right semantics? What if there
 	// is just a key for the IP address, but not for the
 	// hostname?
@@ -365,7 +361,7 @@ func (db *hostKeyDB) checkAddrs(addrs []addr, remoteKey ssh.PublicKey) error {
 	// Algorithm => key.
 	knownKeys := map[string]KnownKey{}
 	for _, l := range db.lines {
-		if l.match(addrs) {
+		if l.match(a) {
 			typ := l.knownKey.Key.Type()
 			if _, ok := knownKeys[typ]; !ok {
 				knownKeys[typ] = l.knownKey
@@ -414,7 +410,10 @@ 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.
+// ssh.ClientConfig.HostKeyCallback. By preference, the key check
+// operates on the hostname if available, i.e. if a server changes its
+// IP address, the host key check will still succeed, even though a
+// record of the new IP address is not available.
 func New(files ...string) (ssh.HostKeyCallback, error) {
 	db := newHostKeyDB()
 	for _, fn := range files {
@@ -536,11 +535,6 @@ func newHashedHost(encoded string) (*hashedHost, error) {
 	return &hashedHost{salt: salt, hash: hash}, nil
 }
 
-func (h *hashedHost) match(addrs []addr) bool {
-	for _, a := range addrs {
-		if bytes.Equal(hashHost(Normalize(a.String()), h.salt), h.hash) {
-			return true
-		}
-	}
-	return false
+func (h *hashedHost) match(a addr) bool {
+	return bytes.Equal(hashHost(Normalize(a.String()), h.salt), h.hash)
 }

vendor/golang.org/x/crypto/ssh/knownhosts/knownhosts_test.go

@@ -166,7 +166,7 @@ func TestBasic(t *testing.T) {
 	str := fmt.Sprintf("#comment\n\nserver.org,%s %s\notherhost %s", testAddr, edKeyStr, ecKeyStr)
 	db := testDB(t, str)
 	if err := db.check("server.org:22", testAddr, edKey); err != nil {
-		t.Errorf("got error %q, want none", err)
+		t.Errorf("got error %v, want none", err)
 	}
 
 	want := KnownKey{
@@ -185,6 +185,33 @@ func TestBasic(t *testing.T) {
 	}
 }
 
+func TestHostNamePrecedence(t *testing.T) {
+	var evilAddr = &net.TCPAddr{
+		IP:   net.IP{66, 66, 66, 66},
+		Port: 22,
+	}
+
+	str := fmt.Sprintf("server.org,%s %s\nevil.org,%s %s", testAddr, edKeyStr, evilAddr, ecKeyStr)
+	db := testDB(t, str)
+
+	if err := db.check("server.org:22", evilAddr, ecKey); err == nil {
+		t.Errorf("check succeeded")
+	} else if _, ok := err.(*KeyError); !ok {
+		t.Errorf("got %T, want *KeyError", err)
+	}
+}
+
+func TestDBOrderingPrecedenceKeyType(t *testing.T) {
+	str := fmt.Sprintf("server.org,%s %s\nserver.org,%s %s", testAddr, edKeyStr, testAddr, alternateEdKeyStr)
+	db := testDB(t, str)
+
+	if err := db.check("server.org:22", testAddr, alternateEdKey); err == nil {
+		t.Errorf("check succeeded")
+	} else if _, ok := err.(*KeyError); !ok {
+		t.Errorf("got %T, want *KeyError", err)
+	}
+}
+
 func TestNegate(t *testing.T) {
 	str := fmt.Sprintf("%s,!server.org %s", testAddr, edKeyStr)
 	db := testDB(t, str)

vendor/golang.org/x/crypto/ssh/mux_test.go

@@ -108,10 +108,6 @@ func TestMuxReadWrite(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Write: %v", err)
 		}
-		err = s.Close()
-		if err != nil {
-			t.Fatalf("Close: %v", err)
-		}
 	}()
 
 	var buf [1024]byte

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":

vendor/golang.org/x/crypto/ssh/streamlocal.go

@@ -32,6 +32,7 @@ type streamLocalChannelForwardMsg struct {
 
 // ListenUnix is similar to ListenTCP but uses a Unix domain socket.
 func (c *Client) ListenUnix(socketPath string) (net.Listener, error) {
+	c.handleForwardsOnce.Do(c.handleForwards)
 	m := streamLocalChannelForwardMsg{
 		socketPath,
 	}

vendor/golang.org/x/crypto/ssh/tcpip.go

@@ -90,10 +90,19 @@ type channelForwardMsg struct {
 	rport uint32
 }
 
+// handleForwards starts goroutines handling forwarded connections.
+// It's called on first use by (*Client).ListenTCP to not launch
+// goroutines until needed.
+func (c *Client) handleForwards() {
+	go c.forwards.handleChannels(c.HandleChannelOpen("forwarded-tcpip"))
+	go c.forwards.handleChannels(c.HandleChannelOpen("forwarded-streamlocal@openssh.com"))
+}
+
 // ListenTCP requests the remote peer open a listening socket
 // on laddr. Incoming connections will be available by calling
 // Accept on the returned net.Listener.
 func (c *Client) ListenTCP(laddr *net.TCPAddr) (net.Listener, error) {
+	c.handleForwardsOnce.Do(c.handleForwards)
 	if laddr.Port == 0 && isBrokenOpenSSHVersion(string(c.ServerVersion())) {
 		return c.autoPortListenWorkaround(laddr)
 	}

vendor/golang.org/x/crypto/ssh/terminal/terminal_test.go

@@ -2,12 +2,15 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build darwin dragonfly freebsd linux,!appengine netbsd openbsd windows plan9 solaris
+
 package terminal
 
 import (
 	"bytes"
 	"io"
 	"os"
+	"runtime"
 	"testing"
 )
 
@@ -324,6 +327,11 @@ func TestMakeRawState(t *testing.T) {
 	if err != nil {
 		t.Fatalf("failed to get terminal state from GetState: %s", err)
 	}
+
+	if runtime.GOOS == "darwin" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+		t.Skip("MakeRaw not allowed on iOS; skipping test")
+	}
+
 	defer Restore(fd, st)
 	raw, err := MakeRaw(fd)
 	if err != nil {

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))
 }

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.

vendor/golang.org/x/crypto/ssh/terminal/util_windows.go

@@ -89,9 +89,7 @@ func ReadPassword(fd int) ([]byte, error) {
 		return nil, err
 	}
 
-	defer func() {
-		windows.SetConsoleMode(windows.Handle(fd), old)
-	}()
+	defer windows.SetConsoleMode(windows.Handle(fd), old)
 
 	var h windows.Handle
 	p, _ := windows.GetCurrentProcess()

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)
+			}
+		})
+	}
+}

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;
+}

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()
@@ -236,11 +266,49 @@ 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")
 	}
+	u, err := user.Current()
+	if err != nil {
+		t.Fatalf("user.Current: %v", err)
+	}
+	if u.Name == "root" {
+		t.Skip("skipping test because current user is root")
+	}
 	dir, err := ioutil.TempDir("", "sshtest")
 	if err != nil {
 		t.Fatal(err)
@@ -249,9 +317,11 @@ 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)
 	}