diff --git a/vendor/github.com/mongodb/mongo-go-driver/x/mongo/driver/auth/x509.go b/vendor/github.com/mongodb/mongo-go-driver/x/mongo/driver/auth/x509.go
new file mode 100644
index 0000000..219513b
--- /dev/null
+++ b/vendor/github.com/mongodb/mongo-go-driver/x/mongo/driver/auth/x509.go
@@ -0,0 +1,49 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package auth
+
+import (
+	"context"
+
+	"github.com/mongodb/mongo-go-driver/x/bsonx"
+	"github.com/mongodb/mongo-go-driver/x/network/command"
+	"github.com/mongodb/mongo-go-driver/x/network/description"
+	"github.com/mongodb/mongo-go-driver/x/network/wiremessage"
+)
+
+// MongoDBX509 is the mechanism name for MongoDBX509.
+const MongoDBX509 = "MONGODB-X509"
+
+func newMongoDBX509Authenticator(cred *Cred) (Authenticator, error) {
+	return &MongoDBX509Authenticator{User: cred.Username}, nil
+}
+
+// MongoDBX509Authenticator uses X.509 certificates over TLS to authenticate a connection.
+type MongoDBX509Authenticator struct {
+	User string
+}
+
+// Auth implements the Authenticator interface.
+func (a *MongoDBX509Authenticator) Auth(ctx context.Context, desc description.Server, rw wiremessage.ReadWriter) error {
+	authRequestDoc := bsonx.Doc{
+		{"authenticate", bsonx.Int32(1)},
+		{"mechanism", bsonx.String(MongoDBX509)},
+	}
+
+	if desc.WireVersion.Max < 5 {
+		authRequestDoc = append(authRequestDoc, bsonx.Elem{"user", bsonx.String(a.User)})
+	}
+
+	authCmd := command.Read{DB: "$external", Command: authRequestDoc}
+	ssdesc := description.SelectedServer{Server: desc}
+	_, err := authCmd.RoundTrip(ctx, ssdesc, rw)
+	if err != nil {
+		return newAuthError("round trip error", err)
+	}
+
+	return nil
+}