Bump Go deps

vendor/github.com/go-ldap/ldap/v3/bind.go

@@ -261,7 +261,7 @@ func parseParams(str string) (map[string]string, error) {
 	var state int
 	for i := 0; i <= len(str); i++ {
 		switch state {
-		case 0: //reading key
+		case 0: // reading key
 			if i == len(str) {
 				return nil, fmt.Errorf("syntax error on %d", i)
 			}
@@ -270,7 +270,7 @@ func parseParams(str string) (map[string]string, error) {
 				continue
 			}
 			state = 1
-		case 1: //reading value
+		case 1: // reading value
 			if i == len(str) {
 				m[key] = value
 				break
@@ -289,7 +289,7 @@ func parseParams(str string) (map[string]string, error) {
 			default:
 				value += string(str[i])
 			}
-		case 2: //inside quotes
+		case 2: // inside quotes
 			if i == len(str) {
 				return nil, fmt.Errorf("syntax error on %d", i)
 			}
@@ -399,6 +399,9 @@ type NTLMBindRequest struct {
 	Username string
 	// Password is the credentials to bind with
 	Password string
+	// AllowEmptyPassword sets whether the client allows binding with an empty password
+	// (normally used for unauthenticated bind).
+	AllowEmptyPassword bool
 	// Hash is the hex NTLM hash to bind with. Password or hash must be provided
 	Hash string
 	// Controls are optional controls to send with the bind request
@@ -442,6 +445,22 @@ func (l *Conn) NTLMBind(domain, username, password string) error {
 	return err
 }
 
+// NTLMUnauthenticatedBind performs an bind with an empty password.
+//
+// A username is required. The anonymous bind is not (yet) supported by the go-ntlmssp library (https://github.com/Azure/go-ntlmssp/blob/819c794454d067543bc61d29f61fef4b3c3df62c/authenticate_message.go#L87)
+//
+// See https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-nlmp/b38c36ed-2804-4868-a9ff-8dd3182128e4 part 3.2.5.1.2
+func (l *Conn) NTLMUnauthenticatedBind(domain, username string) error {
+	req := &NTLMBindRequest{
+		Domain:             domain,
+		Username:           username,
+		Password:           "",
+		AllowEmptyPassword: true,
+	}
+	_, err := l.NTLMChallengeBind(req)
+	return err
+}
+
 // NTLMBindWithHash performs an NTLM Bind with an NTLM hash instead of plaintext password (pass-the-hash)
 func (l *Conn) NTLMBindWithHash(domain, username, hash string) error {
 	req := &NTLMBindRequest{
@@ -455,7 +474,7 @@ func (l *Conn) NTLMBindWithHash(domain, username, hash string) error {
 
 // NTLMChallengeBind performs the NTLMSSP bind operation defined in the given request
 func (l *Conn) NTLMChallengeBind(ntlmBindRequest *NTLMBindRequest) (*NTLMBindResult, error) {
-	if ntlmBindRequest.Password == "" && ntlmBindRequest.Hash == "" {
+	if !ntlmBindRequest.AllowEmptyPassword && ntlmBindRequest.Password == "" && ntlmBindRequest.Hash == "" {
 		return nil, NewError(ErrorEmptyPassword, errors.New("ldap: empty password not allowed by the client"))
 	}
 
@@ -496,10 +515,11 @@ func (l *Conn) NTLMChallengeBind(ntlmBindRequest *NTLMBindRequest) (*NTLMBindRes
 		var err error
 		var responseMessage []byte
 		// generate a response message to the challenge with the given Username/Password if password is provided
-		if ntlmBindRequest.Password != "" {
-			responseMessage, err = ntlmssp.ProcessChallenge(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Password)
-		} else if ntlmBindRequest.Hash != "" {
+		if ntlmBindRequest.Hash != "" {
 			responseMessage, err = ntlmssp.ProcessChallengeWithHash(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Hash)
+		} else if ntlmBindRequest.Password != "" || ntlmBindRequest.AllowEmptyPassword {
+			_, _, domainNeeded := ntlmssp.GetDomain(ntlmBindRequest.Username)
+			responseMessage, err = ntlmssp.ProcessChallenge(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Password, domainNeeded)
 		} else {
 			err = fmt.Errorf("need a password or hash to generate reply")
 		}
@@ -538,3 +558,178 @@ func (l *Conn) NTLMChallengeBind(ntlmBindRequest *NTLMBindRequest) (*NTLMBindRes
 	err = GetLDAPError(packet)
 	return result, err
 }
+
+// GSSAPIClient interface is used as the client-side implementation for the
+// GSSAPI SASL mechanism.
+// Interface inspired by GSSAPIClient from golang.org/x/crypto/ssh
+type GSSAPIClient interface {
+	// InitSecContext initiates the establishment of a security context for
+	// GSS-API between the client and server.
+	// Initially the token parameter should be specified as nil.
+	// The routine may return a outputToken which should be transferred to
+	// the server, where the server will present it to AcceptSecContext.
+	// If no token need be sent, InitSecContext will indicate this by setting
+	// needContinue to false. To complete the context
+	// establishment, one or more reply tokens may be required from the server;
+	// if so, InitSecContext will return a needContinue which is true.
+	// In this case, InitSecContext should be called again when the
+	// reply token is received from the server, passing the reply token
+	// to InitSecContext via the token parameters.
+	// See RFC 4752 section 3.1.
+	InitSecContext(target string, token []byte) (outputToken []byte, needContinue bool, err error)
+	// NegotiateSaslAuth performs the last step of the Sasl handshake.
+	// It takes a token, which, when unwrapped, describes the servers supported
+	// security layers (first octet) and maximum receive buffer (remaining
+	// three octets).
+	// If the received token is unacceptable an error must be returned to abort
+	// the handshake.
+	// Outputs a signed token describing the client's selected security layer
+	// and receive buffer size and optionally an authorization identity.
+	// The returned token will be sent to the server and the handshake considered
+	// completed successfully and the server authenticated.
+	// See RFC 4752 section 3.1.
+	NegotiateSaslAuth(token []byte, authzid string) ([]byte, error)
+	// DeleteSecContext destroys any established secure context.
+	DeleteSecContext() error
+}
+
+// GSSAPIBindRequest represents a GSSAPI SASL mechanism bind request.
+// See rfc4752 and rfc4513 section 5.2.1.2.
+type GSSAPIBindRequest struct {
+	// Service Principal Name user for the service ticket. Eg. "ldap/<host>"
+	ServicePrincipalName string
+	// (Optional) Authorization entity
+	AuthZID string
+	// (Optional) Controls to send with the bind request
+	Controls []Control
+}
+
+// GSSAPIBind performs the GSSAPI SASL bind using the provided GSSAPI client.
+func (l *Conn) GSSAPIBind(client GSSAPIClient, servicePrincipal, authzid string) error {
+	return l.GSSAPIBindRequest(client, &GSSAPIBindRequest{
+		ServicePrincipalName: servicePrincipal,
+		AuthZID:              authzid,
+	})
+}
+
+// GSSAPIBindRequest performs the GSSAPI SASL bind using the provided GSSAPI client.
+func (l *Conn) GSSAPIBindRequest(client GSSAPIClient, req *GSSAPIBindRequest) error {
+	//nolint:errcheck
+	defer client.DeleteSecContext()
+
+	var err error
+	var reqToken []byte
+	var recvToken []byte
+	needInit := true
+	for {
+		if needInit {
+			// Establish secure context between client and server.
+			reqToken, needInit, err = client.InitSecContext(req.ServicePrincipalName, recvToken)
+			if err != nil {
+				return err
+			}
+		} else {
+			// Secure context is set up, perform the last step of SASL handshake.
+			reqToken, err = client.NegotiateSaslAuth(recvToken, req.AuthZID)
+			if err != nil {
+				return err
+			}
+		}
+		// Send Bind request containing the current token and extract the
+		// token sent by server.
+		recvToken, err = l.saslBindTokenExchange(req.Controls, reqToken)
+		if err != nil {
+			return err
+		}
+
+		if !needInit && len(recvToken) == 0 {
+			break
+		}
+	}
+
+	return nil
+}
+
+func (l *Conn) saslBindTokenExchange(reqControls []Control, reqToken []byte) ([]byte, error) {
+	// Construct LDAP Bind request with GSSAPI SASL mechanism.
+	envelope := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "LDAP Request")
+	envelope.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, l.nextMessageID(), "MessageID"))
+
+	request := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationBindRequest, nil, "Bind Request")
+	request.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
+	request.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "User Name"))
+
+	auth := ber.Encode(ber.ClassContext, ber.TypeConstructed, 3, "", "authentication")
+	auth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "GSSAPI", "SASL Mech"))
+	if len(reqToken) > 0 {
+		auth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, string(reqToken), "Credentials"))
+	}
+	request.AppendChild(auth)
+	envelope.AppendChild(request)
+	if len(reqControls) > 0 {
+		envelope.AppendChild(encodeControls(reqControls))
+	}
+
+	msgCtx, err := l.sendMessage(envelope)
+	if err != nil {
+		return nil, err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return nil, err
+	}
+	l.Debug.Printf("%d: got response %p", msgCtx.id, packet)
+	if l.Debug {
+		if err = addLDAPDescriptions(packet); err != nil {
+			return nil, err
+		}
+		ber.PrintPacket(packet)
+	}
+
+	// https://www.rfc-editor.org/rfc/rfc4511#section-4.1.1
+	// packet is an envelope
+	// child 0 is message id
+	// child 1 is protocolOp
+	if len(packet.Children) != 2 {
+		return nil, fmt.Errorf("bad bind response")
+	}
+
+	protocolOp := packet.Children[1]
+RESP:
+	switch protocolOp.Description {
+	case "Bind Response": // Bind Response
+		// Bind Reponse is an LDAP Response (https://www.rfc-editor.org/rfc/rfc4511#section-4.1.9)
+		// with an additional optional serverSaslCreds string (https://www.rfc-editor.org/rfc/rfc4511#section-4.2.2)
+		// child 0 is resultCode
+		resultCode := protocolOp.Children[0]
+		if resultCode.Tag != ber.TagEnumerated {
+			break RESP
+		}
+		switch resultCode.Value.(int64) {
+		case 14: // Sasl bind in progress
+			if len(protocolOp.Children) < 3 {
+				break RESP
+			}
+			referral := protocolOp.Children[3]
+			switch referral.Description {
+			case "Referral":
+				if referral.ClassType != ber.ClassContext || referral.Tag != ber.TagObjectDescriptor {
+					break RESP
+				}
+				return ioutil.ReadAll(referral.Data)
+			}
+			// Optional:
+			//if len(protocolOp.Children) == 4 {
+			//	serverSaslCreds := protocolOp.Children[4]
+			//}
+		case 0: // Success - Bind OK.
+			// SASL layer in effect (if any) (See https://www.rfc-editor.org/rfc/rfc4513#section-5.2.1.4)
+			// NOTE: SASL security layers are not supported currently.
+			return nil, nil
+		}
+	}
+
+	return nil, GetLDAPError(packet)
+}