Use mattermost v5 module (#1192)

26 files changed, 3857 insertions, 0 deletions

diff --git a/vendor/github.com/mattermost/ldap/.gitignore b/vendor/github.com/mattermost/ldap/.gitignore
new file mode 100644
index 00000000..e69de29b
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/.gitignore
diff --git a/vendor/github.com/mattermost/ldap/.travis.yml b/vendor/github.com/mattermost/ldap/.travis.yml
new file mode 100644
index 00000000..f2538fd5
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/.travis.yml
@@ -0,0 +1,32 @@
+sudo: false
+language: go
+go:
+    - "1.5.x"
+    - "1.6.x"
+    - "1.7.x"
+    - "1.8.x"
+    - "1.9.x"
+    - "1.10.x"
+    - "1.11.x"
+    - "1.12.x"
+    - "1.13.x"
+    - tip
+
+git:
+    depth: 1
+
+matrix:
+    fast_finish: true
+    allow_failures:
+        - go: tip
+go_import_path: github.com/go-ldap/ldap
+install:
+    - go get github.com/go-asn1-ber/asn1-ber
+    - go get code.google.com/p/go.tools/cmd/cover || go get golang.org/x/tools/cmd/cover
+    - go get github.com/golang/lint/golint || go get golang.org/x/lint/golint || true
+    - go build -v ./...
+script:
+    - make test
+    - make fmt
+    - make vet
+    - make lint
diff --git a/vendor/github.com/mattermost/ldap/CONTRIBUTING.md b/vendor/github.com/mattermost/ldap/CONTRIBUTING.md
new file mode 100644
index 00000000..a7885231
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/CONTRIBUTING.md
@@ -0,0 +1,12 @@
+# Contribution Guidelines
+
+We welcome contribution and improvements.
+
+## Guiding Principles
+
+To begin with here is a draft from an email exchange:
+
+ * take compatibility seriously (our semvers, compatibility with older go versions, etc)
+ * don't tag untested code for release
+ * beware of baking in implicit behavior based on other libraries/tools choices
+ * be as high-fidelity as possible in plumbing through LDAP data (don't mask errors or reduce power of someone using the library)
diff --git a/vendor/github.com/mattermost/ldap/LICENSE b/vendor/github.com/mattermost/ldap/LICENSE
new file mode 100644
index 00000000..6c0ed4b3
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/LICENSE
@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2011-2015 Michael Mitton (mmitton@gmail.com)
+Portions copyright (c) 2015-2016 go-ldap Authors
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/vendor/github.com/mattermost/ldap/Makefile b/vendor/github.com/mattermost/ldap/Makefile
new file mode 100644
index 00000000..c4966472
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/Makefile
@@ -0,0 +1,82 @@
+.PHONY: default install build test quicktest fmt vet lint 
+
+# List of all release tags "supported" by our current Go version
+# E.g. ":go1.1:go1.2:go1.3:go1.4:go1.5:go1.6:go1.7:go1.8:go1.9:go1.10:go1.11:go1.12:"
+GO_RELEASE_TAGS := $(shell go list -f ':{{join (context.ReleaseTags) ":"}}:' runtime)
+
+# Only use the `-race` flag on newer versions of Go (version 1.3 and newer)
+ifeq (,$(findstring :go1.3:,$(GO_RELEASE_TAGS)))
+	RACE_FLAG :=
+else
+	RACE_FLAG := -race -cpu 1,2,4
+endif
+
+# Run `go vet` on Go 1.12 and newer. For Go 1.5-1.11, use `go tool vet`
+ifneq (,$(findstring :go1.12:,$(GO_RELEASE_TAGS)))
+	GO_VET := go vet \
+		-atomic \
+		-bool \
+		-copylocks \
+		-nilfunc \
+		-printf \
+		-rangeloops \
+		-unreachable \
+		-unsafeptr \
+		-unusedresult \
+		.
+else ifneq (,$(findstring :go1.5:,$(GO_RELEASE_TAGS)))
+	GO_VET := go tool vet \
+		-atomic \
+		-bool \
+		-copylocks \
+		-nilfunc \
+		-printf \
+		-shadow \
+		-rangeloops \
+		-unreachable \
+		-unsafeptr \
+		-unusedresult \
+		.
+else
+	GO_VET := @echo "go vet skipped -- not supported on this version of Go"
+endif
+
+default: fmt vet lint build quicktest
+
+install:
+	go get -t -v ./...
+
+build:
+	go build -v ./...
+
+test:
+	go test -v $(RACE_FLAG) -cover ./...
+
+quicktest:
+	go test ./...
+
+# Capture output and force failure when there is non-empty output
+fmt:
+	@echo gofmt -l .
+	@OUTPUT=`gofmt -l . 2>&1`; \
+	if [ "$$OUTPUT" ]; then \
+		echo "gofmt must be run on the following files:"; \
+		echo "$$OUTPUT"; \
+		exit 1; \
+	fi
+
+vet:
+	$(GO_VET)
+
+# https://github.com/golang/lint
+# go get github.com/golang/lint/golint
+# Capture output and force failure when there is non-empty output
+# Only run on go1.5+
+lint:
+	@echo golint ./...
+	@OUTPUT=`command -v golint >/dev/null 2>&1 && golint ./... 2>&1`; \
+	if [ "$$OUTPUT" ]; then \
+		echo "golint errors:"; \
+		echo "$$OUTPUT"; \
+		exit 1; \
+	fi
diff --git a/vendor/github.com/mattermost/ldap/README.md b/vendor/github.com/mattermost/ldap/README.md
new file mode 100644
index 00000000..c61e4883
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/README.md
@@ -0,0 +1,61 @@
+[![GoDoc](https://godoc.org/github.com/go-ldap/ldap?status.svg)](https://godoc.org/github.com/go-ldap/ldap)
+[![Build Status](https://travis-ci.org/go-ldap/ldap.svg)](https://travis-ci.org/go-ldap/ldap)
+
+# Basic LDAP v3 functionality for the GO programming language.
+
+## Features:
+
+ - Connecting to LDAP server (non-TLS, TLS, STARTTLS)
+ - Binding to LDAP server
+ - Searching for entries
+ - Filter Compile / Decompile
+ - Paging Search Results
+ - Modify Requests / Responses
+ - Add Requests / Responses
+ - Delete Requests / Responses
+ - Modify DN Requests / Responses
+
+## Examples:
+
+ - search
+ - modify
+
+## Go Modules:
+
+`go get github.com/go-ldap/ldap/v3`
+
+As go-ldap was v2+ when Go Modules came out, updating to Go Modules would be considered a breaking change.
+
+To maintain backwards compatability, we ultimately decided to use subfolders (as v3 was already a branch).
+Whilst this duplicates the code, we can move toward implementing a backwards-compatible versioning system that allows for code reuse.
+The alternative would be to increment the version number, however we believe that this would confuse users as v3 is in line with LDAPv3 (RFC-4511)
+https://tools.ietf.org/html/rfc4511
+
+
+For more info, please visit the pull request that updated to modules.
+https://github.com/go-ldap/ldap/pull/247
+
+To install with `GOMODULE111=off`, use `go get github.com/go-ldap/ldap`
+https://golang.org/cmd/go/#hdr-Legacy_GOPATH_go_get
+
+As always, we are looking for contributors with great ideas on how to best move forward.
+
+
+## Contributing:
+
+Bug reports and pull requests are welcome!
+
+Before submitting a pull request, please make sure tests and verification scripts pass:
+```
+make all
+```
+
+To set up a pre-push hook to run the tests and verify scripts before pushing:
+```
+ln -s ../../.githooks/pre-push .git/hooks/pre-push
+```
+
+---
+The Go gopher was designed by Renee French. (http://reneefrench.blogspot.com/)
+The design is licensed under the Creative Commons 3.0 Attributions license.
+Read this article for more details: http://blog.golang.org/gopher
diff --git a/vendor/github.com/mattermost/ldap/add.go b/vendor/github.com/mattermost/ldap/add.go
new file mode 100644
index 00000000..a3e6b881
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/add.go
@@ -0,0 +1,100 @@
+//
+// https://tools.ietf.org/html/rfc4511
+//
+// AddRequest ::= [APPLICATION 8] SEQUENCE {
+//      entry           LDAPDN,
+//      attributes      AttributeList }
+//
+// AttributeList ::= SEQUENCE OF attribute Attribute
+
+package ldap
+
+import (
+	"log"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// Attribute represents an LDAP attribute
+type Attribute struct {
+	// Type is the name of the LDAP attribute
+	Type string
+	// Vals are the LDAP attribute values
+	Vals []string
+}
+
+func (a *Attribute) encode() *ber.Packet {
+	seq := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Attribute")
+	seq.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, a.Type, "Type"))
+	set := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSet, nil, "AttributeValue")
+	for _, value := range a.Vals {
+		set.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, value, "Vals"))
+	}
+	seq.AppendChild(set)
+	return seq
+}
+
+// AddRequest represents an LDAP AddRequest operation
+type AddRequest struct {
+	// DN identifies the entry being added
+	DN string
+	// Attributes list the attributes of the new entry
+	Attributes []Attribute
+	// Controls hold optional controls to send with the request
+	Controls []Control
+}
+
+func (req *AddRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationAddRequest, nil, "Add Request")
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.DN, "DN"))
+	attributes := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Attributes")
+	for _, attribute := range req.Attributes {
+		attributes.AppendChild(attribute.encode())
+	}
+	pkt.AppendChild(attributes)
+
+	envelope.AppendChild(pkt)
+	if len(req.Controls) > 0 {
+		envelope.AppendChild(encodeControls(req.Controls))
+	}
+
+	return nil
+}
+
+// Attribute adds an attribute with the given type and values
+func (req *AddRequest) Attribute(attrType string, attrVals []string) {
+	req.Attributes = append(req.Attributes, Attribute{Type: attrType, Vals: attrVals})
+}
+
+// NewAddRequest returns an AddRequest for the given DN, with no attributes
+func NewAddRequest(dn string, controls []Control) *AddRequest {
+	return &AddRequest{
+		DN:       dn,
+		Controls: controls,
+	}
+
+}
+
+// Add performs the given AddRequest
+func (l *Conn) Add(addRequest *AddRequest) error {
+	msgCtx, err := l.doRequest(addRequest)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return err
+	}
+
+	if packet.Children[1].Tag == ApplicationAddResponse {
+		err := GetLDAPError(packet)
+		if err != nil {
+			return err
+		}
+	} else {
+		log.Printf("Unexpected Response: %d", packet.Children[1].Tag)
+	}
+	return nil
+}
diff --git a/vendor/github.com/mattermost/ldap/bind.go b/vendor/github.com/mattermost/ldap/bind.go
new file mode 100644
index 00000000..15307f50
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/bind.go
@@ -0,0 +1,152 @@
+package ldap
+
+import (
+	"errors"
+	"fmt"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// SimpleBindRequest represents a username/password bind operation
+type SimpleBindRequest struct {
+	// Username is the name of the Directory object that the client wishes to bind as
+	Username string
+	// Password is the credentials to bind with
+	Password string
+	// Controls are optional controls to send with the bind request
+	Controls []Control
+	// AllowEmptyPassword sets whether the client allows binding with an empty password
+	// (normally used for unauthenticated bind).
+	AllowEmptyPassword bool
+}
+
+// SimpleBindResult contains the response from the server
+type SimpleBindResult struct {
+	Controls []Control
+}
+
+// NewSimpleBindRequest returns a bind request
+func NewSimpleBindRequest(username string, password string, controls []Control) *SimpleBindRequest {
+	return &SimpleBindRequest{
+		Username:           username,
+		Password:           password,
+		Controls:           controls,
+		AllowEmptyPassword: false,
+	}
+}
+
+func (req *SimpleBindRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationBindRequest, nil, "Bind Request")
+	pkt.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Username, "User Name"))
+	pkt.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, req.Password, "Password"))
+
+	envelope.AppendChild(pkt)
+	if len(req.Controls) > 0 {
+		envelope.AppendChild(encodeControls(req.Controls))
+	}
+
+	return nil
+}
+
+// SimpleBind performs the simple bind operation defined in the given request
+func (l *Conn) SimpleBind(simpleBindRequest *SimpleBindRequest) (*SimpleBindResult, error) {
+	if simpleBindRequest.Password == "" && !simpleBindRequest.AllowEmptyPassword {
+		return nil, NewError(ErrorEmptyPassword, errors.New("ldap: empty password not allowed by the client"))
+	}
+
+	msgCtx, err := l.doRequest(simpleBindRequest)
+	if err != nil {
+		return nil, err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return nil, err
+	}
+
+	result := &SimpleBindResult{
+		Controls: make([]Control, 0),
+	}
+
+	if len(packet.Children) == 3 {
+		for _, child := range packet.Children[2].Children {
+			decodedChild, decodeErr := DecodeControl(child)
+			if decodeErr != nil {
+				return nil, fmt.Errorf("failed to decode child control: %s", decodeErr)
+			}
+			result.Controls = append(result.Controls, decodedChild)
+		}
+	}
+
+	err = GetLDAPError(packet)
+	return result, err
+}
+
+// Bind performs a bind with the given username and password.
+//
+// It does not allow unauthenticated bind (i.e. empty password). Use the UnauthenticatedBind method
+// for that.
+func (l *Conn) Bind(username, password string) error {
+	req := &SimpleBindRequest{
+		Username:           username,
+		Password:           password,
+		AllowEmptyPassword: false,
+	}
+	_, err := l.SimpleBind(req)
+	return err
+}
+
+// UnauthenticatedBind performs an unauthenticated bind.
+//
+// A username may be provided for trace (e.g. logging) purpose only, but it is normally not
+// authenticated or otherwise validated by the LDAP server.
+//
+// See https://tools.ietf.org/html/rfc4513#section-5.1.2 .
+// See https://tools.ietf.org/html/rfc4513#section-6.3.1 .
+func (l *Conn) UnauthenticatedBind(username string) error {
+	req := &SimpleBindRequest{
+		Username:           username,
+		Password:           "",
+		AllowEmptyPassword: true,
+	}
+	_, err := l.SimpleBind(req)
+	return err
+}
+
+var externalBindRequest = requestFunc(func(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationBindRequest, nil, "Bind Request")
+	pkt.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "User Name"))
+
+	saslAuth := ber.Encode(ber.ClassContext, ber.TypeConstructed, 3, "", "authentication")
+	saslAuth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "EXTERNAL", "SASL Mech"))
+	saslAuth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "SASL Cred"))
+
+	pkt.AppendChild(saslAuth)
+
+	envelope.AppendChild(pkt)
+
+	return nil
+})
+
+// ExternalBind performs SASL/EXTERNAL authentication.
+//
+// Use ldap.DialURL("ldapi://") to connect to the Unix socket before ExternalBind.
+//
+// See https://tools.ietf.org/html/rfc4422#appendix-A
+func (l *Conn) ExternalBind() error {
+	msgCtx, err := l.doRequest(externalBindRequest)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return err
+	}
+
+	return GetLDAPError(packet)
+}
diff --git a/vendor/github.com/mattermost/ldap/client.go b/vendor/github.com/mattermost/ldap/client.go
new file mode 100644
index 00000000..619677c7
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/client.go
@@ -0,0 +1,30 @@
+package ldap
+
+import (
+	"crypto/tls"
+	"time"
+)
+
+// Client knows how to interact with an LDAP server
+type Client interface {
+	Start()
+	StartTLS(*tls.Config) error
+	Close()
+	SetTimeout(time.Duration)
+
+	Bind(username, password string) error
+	UnauthenticatedBind(username string) error
+	SimpleBind(*SimpleBindRequest) (*SimpleBindResult, error)
+	ExternalBind() error
+
+	Add(*AddRequest) error
+	Del(*DelRequest) error
+	Modify(*ModifyRequest) error
+	ModifyDN(*ModifyDNRequest) error
+
+	Compare(dn, attribute, value string) (bool, error)
+	PasswordModify(*PasswordModifyRequest) (*PasswordModifyResult, error)
+
+	Search(*SearchRequest) (*SearchResult, error)
+	SearchWithPaging(searchRequest *SearchRequest, pagingSize uint32) (*SearchResult, error)
+}
diff --git a/vendor/github.com/mattermost/ldap/compare.go b/vendor/github.com/mattermost/ldap/compare.go
new file mode 100644
index 00000000..04a2e17c
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/compare.go
@@ -0,0 +1,80 @@
+// File contains Compare functionality
+//
+// https://tools.ietf.org/html/rfc4511
+//
+// CompareRequest ::= [APPLICATION 14] SEQUENCE {
+//              entry           LDAPDN,
+//              ava             AttributeValueAssertion }
+//
+// AttributeValueAssertion ::= SEQUENCE {
+//              attributeDesc   AttributeDescription,
+//              assertionValue  AssertionValue }
+//
+// AttributeDescription ::= LDAPString
+//                         -- Constrained to <attributedescription>
+//                         -- [RFC4512]
+//
+// AttributeValue ::= OCTET STRING
+//
+
+package ldap
+
+import (
+	"fmt"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// CompareRequest represents an LDAP CompareRequest operation.
+type CompareRequest struct {
+	DN        string
+	Attribute string
+	Value     string
+}
+
+func (req *CompareRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationCompareRequest, nil, "Compare Request")
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.DN, "DN"))
+
+	ava := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "AttributeValueAssertion")
+	ava.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Attribute, "AttributeDesc"))
+	ava.AppendChild(ber.Encode(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.Value, "AssertionValue"))
+
+	pkt.AppendChild(ava)
+
+	envelope.AppendChild(pkt)
+
+	return nil
+}
+
+// Compare checks to see if the attribute of the dn matches value. Returns true if it does otherwise
+// false with any error that occurs if any.
+func (l *Conn) Compare(dn, attribute, value string) (bool, error) {
+	msgCtx, err := l.doRequest(&CompareRequest{
+		DN:        dn,
+		Attribute: attribute,
+		Value:     value})
+	if err != nil {
+		return false, err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return false, err
+	}
+
+	if packet.Children[1].Tag == ApplicationCompareResponse {
+		err := GetLDAPError(packet)
+
+		switch {
+		case IsErrorWithCode(err, LDAPResultCompareTrue):
+			return true, nil
+		case IsErrorWithCode(err, LDAPResultCompareFalse):
+			return false, nil
+		default:
+			return false, err
+		}
+	}
+	return false, fmt.Errorf("unexpected Response: %d", packet.Children[1].Tag)
+}
diff --git a/vendor/github.com/mattermost/ldap/conn.go b/vendor/github.com/mattermost/ldap/conn.go
new file mode 100644
index 00000000..5b7ac478
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/conn.go
@@ -0,0 +1,522 @@
+package ldap
+
+import (
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"net/url"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+const (
+	// MessageQuit causes the processMessages loop to exit
+	MessageQuit = 0
+	// MessageRequest sends a request to the server
+	MessageRequest = 1
+	// MessageResponse receives a response from the server
+	MessageResponse = 2
+	// MessageFinish indicates the client considers a particular message ID to be finished
+	MessageFinish = 3
+	// MessageTimeout indicates the client-specified timeout for a particular message ID has been reached
+	MessageTimeout = 4
+)
+
+const (
+	// DefaultLdapPort default ldap port for pure TCP connection
+	DefaultLdapPort = "389"
+	// DefaultLdapsPort default ldap port for SSL connection
+	DefaultLdapsPort = "636"
+)
+
+// PacketResponse contains the packet or error encountered reading a response
+type PacketResponse struct {
+	// Packet is the packet read from the server
+	Packet *ber.Packet
+	// Error is an error encountered while reading
+	Error error
+}
+
+// ReadPacket returns the packet or an error
+func (pr *PacketResponse) ReadPacket() (*ber.Packet, error) {
+	if (pr == nil) || (pr.Packet == nil && pr.Error == nil) {
+		return nil, NewError(ErrorNetwork, errors.New("ldap: could not retrieve response"))
+	}
+	return pr.Packet, pr.Error
+}
+
+type messageContext struct {
+	id int64
+	// close(done) should only be called from finishMessage()
+	done chan struct{}
+	// close(responses) should only be called from processMessages(), and only sent to from sendResponse()
+	responses chan *PacketResponse
+}
+
+// sendResponse should only be called within the processMessages() loop which
+// is also responsible for closing the responses channel.
+func (msgCtx *messageContext) sendResponse(packet *PacketResponse) {
+	select {
+	case msgCtx.responses <- packet:
+		// Successfully sent packet to message handler.
+	case <-msgCtx.done:
+		// The request handler is done and will not receive more
+		// packets.
+	}
+}
+
+type messagePacket struct {
+	Op        int
+	MessageID int64
+	Packet    *ber.Packet
+	Context   *messageContext
+}
+
+type sendMessageFlags uint
+
+const (
+	startTLS sendMessageFlags = 1 << iota
+)
+
+// Conn represents an LDAP Connection
+type Conn struct {
+	// requestTimeout is loaded atomically
+	// so we need to ensure 64-bit alignment on 32-bit platforms.
+	requestTimeout      int64
+	conn                net.Conn
+	isTLS               bool
+	closing             uint32
+	closeErr            atomic.Value
+	isStartingTLS       bool
+	Debug               debugging
+	chanConfirm         chan struct{}
+	messageContexts     map[int64]*messageContext
+	chanMessage         chan *messagePacket
+	chanMessageID       chan int64
+	wgClose             sync.WaitGroup
+	outstandingRequests uint
+	messageMutex        sync.Mutex
+}
+
+var _ Client = &Conn{}
+
+// DefaultTimeout is a package-level variable that sets the timeout value
+// used for the Dial and DialTLS methods.
+//
+// WARNING: since this is a package-level variable, setting this value from
+// multiple places will probably result in undesired behaviour.
+var DefaultTimeout = 60 * time.Second
+
+// Dial connects to the given address on the given network using net.Dial
+// and then returns a new Conn for the connection.
+func Dial(network, addr string) (*Conn, error) {
+	c, err := net.DialTimeout(network, addr, DefaultTimeout)
+	if err != nil {
+		return nil, NewError(ErrorNetwork, err)
+	}
+	conn := NewConn(c, false)
+	conn.Start()
+	return conn, nil
+}
+
+// DialTLS connects to the given address on the given network using tls.Dial
+// and then returns a new Conn for the connection.
+func DialTLS(network, addr string, config *tls.Config) (*Conn, error) {
+	c, err := tls.DialWithDialer(&net.Dialer{Timeout: DefaultTimeout}, network, addr, config)
+	if err != nil {
+		return nil, NewError(ErrorNetwork, err)
+	}
+	conn := NewConn(c, true)
+	conn.Start()
+	return conn, nil
+}
+
+// DialURL connects to the given ldap URL vie TCP using tls.Dial or net.Dial if ldaps://
+// or ldap:// specified as protocol. On success a new Conn for the connection
+// is returned.
+func DialURL(addr string) (*Conn, error) {
+	lurl, err := url.Parse(addr)
+	if err != nil {
+		return nil, NewError(ErrorNetwork, err)
+	}
+
+	host, port, err := net.SplitHostPort(lurl.Host)
+	if err != nil {
+		// we asume that error is due to missing port
+		host = lurl.Host
+		port = ""
+	}
+
+	switch lurl.Scheme {
+	case "ldapi":
+		if lurl.Path == "" || lurl.Path == "/" {
+			lurl.Path = "/var/run/slapd/ldapi"
+		}
+		return Dial("unix", lurl.Path)
+	case "ldap":
+		if port == "" {
+			port = DefaultLdapPort
+		}
+		return Dial("tcp", net.JoinHostPort(host, port))
+	case "ldaps":
+		if port == "" {
+			port = DefaultLdapsPort
+		}
+		tlsConf := &tls.Config{
+			ServerName: host,
+		}
+		return DialTLS("tcp", net.JoinHostPort(host, port), tlsConf)
+	}
+
+	return nil, NewError(ErrorNetwork, fmt.Errorf("Unknown scheme '%s'", lurl.Scheme))
+}
+
+// NewConn returns a new Conn using conn for network I/O.
+func NewConn(conn net.Conn, isTLS bool) *Conn {
+	return &Conn{
+		conn:            conn,
+		chanConfirm:     make(chan struct{}),
+		chanMessageID:   make(chan int64),
+		chanMessage:     make(chan *messagePacket, 10),
+		messageContexts: map[int64]*messageContext{},
+		requestTimeout:  0,
+		isTLS:           isTLS,
+	}
+}
+
+// Start initializes goroutines to read responses and process messages
+func (l *Conn) Start() {
+	l.wgClose.Add(1)
+	go l.reader()
+	go l.processMessages()
+}
+
+// IsClosing returns whether or not we're currently closing.
+func (l *Conn) IsClosing() bool {
+	return atomic.LoadUint32(&l.closing) == 1
+}
+
+// setClosing sets the closing value to true
+func (l *Conn) setClosing() bool {
+	return atomic.CompareAndSwapUint32(&l.closing, 0, 1)
+}
+
+// Close closes the connection.
+func (l *Conn) Close() {
+	l.messageMutex.Lock()
+	defer l.messageMutex.Unlock()
+
+	if l.setClosing() {
+		l.Debug.Printf("Sending quit message and waiting for confirmation")
+		l.chanMessage <- &messagePacket{Op: MessageQuit}
+		<-l.chanConfirm
+		close(l.chanMessage)
+
+		l.Debug.Printf("Closing network connection")
+		if err := l.conn.Close(); err != nil {
+			log.Println(err)
+		}
+
+		l.wgClose.Done()
+	}
+	l.wgClose.Wait()
+}
+
+// SetTimeout sets the time after a request is sent that a MessageTimeout triggers
+func (l *Conn) SetTimeout(timeout time.Duration) {
+	if timeout > 0 {
+		atomic.StoreInt64(&l.requestTimeout, int64(timeout))
+	}
+}
+
+// Returns the next available messageID
+func (l *Conn) nextMessageID() int64 {
+	if messageID, ok := <-l.chanMessageID; ok {
+		return messageID
+	}
+	return 0
+}
+
+// StartTLS sends the command to start a TLS session and then creates a new TLS Client
+func (l *Conn) StartTLS(config *tls.Config) error {
+	if l.isTLS {
+		return NewError(ErrorNetwork, errors.New("ldap: already encrypted"))
+	}
+
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "LDAP Request")
+	packet.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, l.nextMessageID(), "MessageID"))
+	request := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationExtendedRequest, nil, "Start TLS")
+	request.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, "1.3.6.1.4.1.1466.20037", "TLS Extended Command"))
+	packet.AppendChild(request)
+	l.Debug.PrintPacket(packet)
+
+	msgCtx, err := l.sendMessageWithFlags(packet, startTLS)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	l.Debug.Printf("%d: waiting for response", msgCtx.id)
+
+	packetResponse, ok := <-msgCtx.responses
+	if !ok {
+		return NewError(ErrorNetwork, errors.New("ldap: response channel closed"))
+	}
+	packet, err = packetResponse.ReadPacket()
+	l.Debug.Printf("%d: got response %p", msgCtx.id, packet)
+	if err != nil {
+		return err
+	}
+
+	if l.Debug {
+		if err := addLDAPDescriptions(packet); err != nil {
+			l.Close()
+			return err
+		}
+		l.Debug.PrintPacket(packet)
+	}
+
+	if err := GetLDAPError(packet); err == nil {
+		conn := tls.Client(l.conn, config)
+
+		if connErr := conn.Handshake(); connErr != nil {
+			l.Close()
+			return NewError(ErrorNetwork, fmt.Errorf("TLS handshake failed (%v)", connErr))
+		}
+
+		l.isTLS = true
+		l.conn = conn
+	} else {
+		return err
+	}
+	go l.reader()
+
+	return nil
+}
+
+// TLSConnectionState returns the client's TLS connection state.
+// The return values are their zero values if StartTLS did
+// not succeed.
+func (l *Conn) TLSConnectionState() (state tls.ConnectionState, ok bool) {
+	tc, ok := l.conn.(*tls.Conn)
+	if !ok {
+		return
+	}
+	return tc.ConnectionState(), true
+}
+
+func (l *Conn) sendMessage(packet *ber.Packet) (*messageContext, error) {
+	return l.sendMessageWithFlags(packet, 0)
+}
+
+func (l *Conn) sendMessageWithFlags(packet *ber.Packet, flags sendMessageFlags) (*messageContext, error) {
+	if l.IsClosing() {
+		return nil, NewError(ErrorNetwork, errors.New("ldap: connection closed"))
+	}
+	l.messageMutex.Lock()
+	l.Debug.Printf("flags&startTLS = %d", flags&startTLS)
+	if l.isStartingTLS {
+		l.messageMutex.Unlock()
+		return nil, NewError(ErrorNetwork, errors.New("ldap: connection is in startls phase"))
+	}
+	if flags&startTLS != 0 {
+		if l.outstandingRequests != 0 {
+			l.messageMutex.Unlock()
+			return nil, NewError(ErrorNetwork, errors.New("ldap: cannot StartTLS with outstanding requests"))
+		}
+		l.isStartingTLS = true
+	}
+	l.outstandingRequests++
+
+	l.messageMutex.Unlock()
+
+	responses := make(chan *PacketResponse)
+	messageID := packet.Children[0].Value.(int64)
+	message := &messagePacket{
+		Op:        MessageRequest,
+		MessageID: messageID,
+		Packet:    packet,
+		Context: &messageContext{
+			id:        messageID,
+			done:      make(chan struct{}),
+			responses: responses,
+		},
+	}
+	l.sendProcessMessage(message)
+	return message.Context, nil
+}
+
+func (l *Conn) finishMessage(msgCtx *messageContext) {
+	close(msgCtx.done)
+
+	if l.IsClosing() {
+		return
+	}
+
+	l.messageMutex.Lock()
+	l.outstandingRequests--
+	if l.isStartingTLS {
+		l.isStartingTLS = false
+	}
+	l.messageMutex.Unlock()
+
+	message := &messagePacket{
+		Op:        MessageFinish,
+		MessageID: msgCtx.id,
+	}
+	l.sendProcessMessage(message)
+}
+
+func (l *Conn) sendProcessMessage(message *messagePacket) bool {
+	l.messageMutex.Lock()
+	defer l.messageMutex.Unlock()
+	if l.IsClosing() {
+		return false
+	}
+	l.chanMessage <- message
+	return true
+}
+
+func (l *Conn) processMessages() {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("ldap: recovered panic in processMessages: %v", err)
+		}
+		for messageID, msgCtx := range l.messageContexts {
+			// If we are closing due to an error, inform anyone who
+			// is waiting about the error.
+			if l.IsClosing() && l.closeErr.Load() != nil {
+				msgCtx.sendResponse(&PacketResponse{Error: l.closeErr.Load().(error)})
+			}
+			l.Debug.Printf("Closing channel for MessageID %d", messageID)
+			close(msgCtx.responses)
+			delete(l.messageContexts, messageID)
+		}
+		close(l.chanMessageID)
+		close(l.chanConfirm)
+	}()
+
+	var messageID int64 = 1
+	for {
+		select {
+		case l.chanMessageID <- messageID:
+			messageID++
+		case message := <-l.chanMessage:
+			switch message.Op {
+			case MessageQuit:
+				l.Debug.Printf("Shutting down - quit message received")
+				return
+			case MessageRequest:
+				// Add to message list and write to network
+				l.Debug.Printf("Sending message %d", message.MessageID)
+
+				buf := message.Packet.Bytes()
+				_, err := l.conn.Write(buf)
+				if err != nil {
+					l.Debug.Printf("Error Sending Message: %s", err.Error())
+					message.Context.sendResponse(&PacketResponse{Error: fmt.Errorf("unable to send request: %s", err)})
+					close(message.Context.responses)
+					break
+				}
+
+				// Only add to messageContexts if we were able to
+				// successfully write the message.
+				l.messageContexts[message.MessageID] = message.Context
+
+				// Add timeout if defined
+				requestTimeout := time.Duration(atomic.LoadInt64(&l.requestTimeout))
+				if requestTimeout > 0 {
+					go func() {
+						defer func() {
+							if err := recover(); err != nil {
+								log.Printf("ldap: recovered panic in RequestTimeout: %v", err)
+							}
+						}()
+						time.Sleep(requestTimeout)
+						timeoutMessage := &messagePacket{
+							Op:        MessageTimeout,
+							MessageID: message.MessageID,
+						}
+						l.sendProcessMessage(timeoutMessage)
+					}()
+				}
+			case MessageResponse:
+				l.Debug.Printf("Receiving message %d", message.MessageID)
+				if msgCtx, ok := l.messageContexts[message.MessageID]; ok {
+					msgCtx.sendResponse(&PacketResponse{message.Packet, nil})
+				} else {
+					log.Printf("Received unexpected message %d, %v", message.MessageID, l.IsClosing())
+					l.Debug.PrintPacket(message.Packet)
+				}
+			case MessageTimeout:
+				// Handle the timeout by closing the channel
+				// All reads will return immediately
+				if msgCtx, ok := l.messageContexts[message.MessageID]; ok {
+					l.Debug.Printf("Receiving message timeout for %d", message.MessageID)
+					msgCtx.sendResponse(&PacketResponse{message.Packet, errors.New("ldap: connection timed out")})
+					delete(l.messageContexts, message.MessageID)
+					close(msgCtx.responses)
+				}
+			case MessageFinish:
+				l.Debug.Printf("Finished message %d", message.MessageID)
+				if msgCtx, ok := l.messageContexts[message.MessageID]; ok {
+					delete(l.messageContexts, message.MessageID)
+					close(msgCtx.responses)
+				}
+			}
+		}
+	}
+}
+
+func (l *Conn) reader() {
+	cleanstop := false
+	defer func() {
+		if err := recover(); err != nil {
+			log.Printf("ldap: recovered panic in reader: %v", err)
+		}
+		if !cleanstop {
+			l.Close()
+		}
+	}()
+
+	for {
+		if cleanstop {
+			l.Debug.Printf("reader clean stopping (without closing the connection)")
+			return
+		}
+		packet, err := ber.ReadPacket(l.conn)
+		if err != nil {
+			// A read error is expected here if we are closing the connection...
+			if !l.IsClosing() {
+				l.closeErr.Store(fmt.Errorf("unable to read LDAP response packet: %s", err))
+				l.Debug.Printf("reader error: %s", err)
+			}
+			return
+		}
+		if err := addLDAPDescriptions(packet); err != nil {
+			l.Debug.Printf("descriptions error: %s", err)
+		}
+		if len(packet.Children) == 0 {
+			l.Debug.Printf("Received bad ldap packet")
+			continue
+		}
+		l.messageMutex.Lock()
+		if l.isStartingTLS {
+			cleanstop = true
+		}
+		l.messageMutex.Unlock()
+		message := &messagePacket{
+			Op:        MessageResponse,
+			MessageID: packet.Children[0].Value.(int64),
+			Packet:    packet,
+		}
+		if !l.sendProcessMessage(message) {
+			return
+		}
+	}
+}
diff --git a/vendor/github.com/mattermost/ldap/control.go b/vendor/github.com/mattermost/ldap/control.go
new file mode 100644
index 00000000..463fe3a3
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/control.go
@@ -0,0 +1,499 @@
+package ldap
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/go-asn1-ber/asn1-ber"
+)
+
+const (
+	// ControlTypePaging - https://www.ietf.org/rfc/rfc2696.txt
+	ControlTypePaging = "1.2.840.113556.1.4.319"
+	// ControlTypeBeheraPasswordPolicy - https://tools.ietf.org/html/draft-behera-ldap-password-policy-10
+	ControlTypeBeheraPasswordPolicy = "1.3.6.1.4.1.42.2.27.8.5.1"
+	// ControlTypeVChuPasswordMustChange - https://tools.ietf.org/html/draft-vchu-ldap-pwd-policy-00
+	ControlTypeVChuPasswordMustChange = "2.16.840.1.113730.3.4.4"
+	// ControlTypeVChuPasswordWarning - https://tools.ietf.org/html/draft-vchu-ldap-pwd-policy-00
+	ControlTypeVChuPasswordWarning = "2.16.840.1.113730.3.4.5"
+	// ControlTypeManageDsaIT - https://tools.ietf.org/html/rfc3296
+	ControlTypeManageDsaIT = "2.16.840.1.113730.3.4.2"
+
+	// ControlTypeMicrosoftNotification - https://msdn.microsoft.com/en-us/library/aa366983(v=vs.85).aspx
+	ControlTypeMicrosoftNotification = "1.2.840.113556.1.4.528"
+	// ControlTypeMicrosoftShowDeleted - https://msdn.microsoft.com/en-us/library/aa366989(v=vs.85).aspx
+	ControlTypeMicrosoftShowDeleted = "1.2.840.113556.1.4.417"
+)
+
+// ControlTypeMap maps controls to text descriptions
+var ControlTypeMap = map[string]string{
+	ControlTypePaging:                "Paging",
+	ControlTypeBeheraPasswordPolicy:  "Password Policy - Behera Draft",
+	ControlTypeManageDsaIT:           "Manage DSA IT",
+	ControlTypeMicrosoftNotification: "Change Notification - Microsoft",
+	ControlTypeMicrosoftShowDeleted:  "Show Deleted Objects - Microsoft",
+}
+
+// Control defines an interface controls provide to encode and describe themselves
+type Control interface {
+	// GetControlType returns the OID
+	GetControlType() string
+	// Encode returns the ber packet representation
+	Encode() *ber.Packet
+	// String returns a human-readable description
+	String() string
+}
+
+// ControlString implements the Control interface for simple controls
+type ControlString struct {
+	ControlType  string
+	Criticality  bool
+	ControlValue string
+}
+
+// GetControlType returns the OID
+func (c *ControlString) GetControlType() string {
+	return c.ControlType
+}
+
+// Encode returns the ber packet representation
+func (c *ControlString) Encode() *ber.Packet {
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
+	packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, c.ControlType, "Control Type ("+ControlTypeMap[c.ControlType]+")"))
+	if c.Criticality {
+		packet.AppendChild(ber.NewBoolean(ber.ClassUniversal, ber.TypePrimitive, ber.TagBoolean, c.Criticality, "Criticality"))
+	}
+	if c.ControlValue != "" {
+		packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, string(c.ControlValue), "Control Value"))
+	}
+	return packet
+}
+
+// String returns a human-readable description
+func (c *ControlString) String() string {
+	return fmt.Sprintf("Control Type: %s (%q)  Criticality: %t  Control Value: %s", ControlTypeMap[c.ControlType], c.ControlType, c.Criticality, c.ControlValue)
+}
+
+// ControlPaging implements the paging control described in https://www.ietf.org/rfc/rfc2696.txt
+type ControlPaging struct {
+	// PagingSize indicates the page size
+	PagingSize uint32
+	// Cookie is an opaque value returned by the server to track a paging cursor
+	Cookie []byte
+}
+
+// GetControlType returns the OID
+func (c *ControlPaging) GetControlType() string {
+	return ControlTypePaging
+}
+
+// Encode returns the ber packet representation
+func (c *ControlPaging) Encode() *ber.Packet {
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
+	packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, ControlTypePaging, "Control Type ("+ControlTypeMap[ControlTypePaging]+")"))
+
+	p2 := ber.Encode(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, nil, "Control Value (Paging)")
+	seq := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Search Control Value")
+	seq.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, int64(c.PagingSize), "Paging Size"))
+	cookie := ber.Encode(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, nil, "Cookie")
+	cookie.Value = c.Cookie
+	cookie.Data.Write(c.Cookie)
+	seq.AppendChild(cookie)
+	p2.AppendChild(seq)
+
+	packet.AppendChild(p2)
+	return packet
+}
+
+// String returns a human-readable description
+func (c *ControlPaging) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)  Criticality: %t  PagingSize: %d  Cookie: %q",
+		ControlTypeMap[ControlTypePaging],
+		ControlTypePaging,
+		false,
+		c.PagingSize,
+		c.Cookie)
+}
+
+// SetCookie stores the given cookie in the paging control
+func (c *ControlPaging) SetCookie(cookie []byte) {
+	c.Cookie = cookie
+}
+
+// ControlBeheraPasswordPolicy implements the control described in https://tools.ietf.org/html/draft-behera-ldap-password-policy-10
+type ControlBeheraPasswordPolicy struct {
+	// Expire contains the number of seconds before a password will expire
+	Expire int64
+	// Grace indicates the remaining number of times a user will be allowed to authenticate with an expired password
+	Grace int64
+	// Error indicates the error code
+	Error int8
+	// ErrorString is a human readable error
+	ErrorString string
+}
+
+// GetControlType returns the OID
+func (c *ControlBeheraPasswordPolicy) GetControlType() string {
+	return ControlTypeBeheraPasswordPolicy
+}
+
+// Encode returns the ber packet representation
+func (c *ControlBeheraPasswordPolicy) Encode() *ber.Packet {
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
+	packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, ControlTypeBeheraPasswordPolicy, "Control Type ("+ControlTypeMap[ControlTypeBeheraPasswordPolicy]+")"))
+
+	return packet
+}
+
+// String returns a human-readable description
+func (c *ControlBeheraPasswordPolicy) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)  Criticality: %t  Expire: %d  Grace: %d  Error: %d, ErrorString: %s",
+		ControlTypeMap[ControlTypeBeheraPasswordPolicy],
+		ControlTypeBeheraPasswordPolicy,
+		false,
+		c.Expire,
+		c.Grace,
+		c.Error,
+		c.ErrorString)
+}
+
+// ControlVChuPasswordMustChange implements the control described in https://tools.ietf.org/html/draft-vchu-ldap-pwd-policy-00
+type ControlVChuPasswordMustChange struct {
+	// MustChange indicates if the password is required to be changed
+	MustChange bool
+}
+
+// GetControlType returns the OID
+func (c *ControlVChuPasswordMustChange) GetControlType() string {
+	return ControlTypeVChuPasswordMustChange
+}
+
+// Encode returns the ber packet representation
+func (c *ControlVChuPasswordMustChange) Encode() *ber.Packet {
+	return nil
+}
+
+// String returns a human-readable description
+func (c *ControlVChuPasswordMustChange) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)  Criticality: %t  MustChange: %v",
+		ControlTypeMap[ControlTypeVChuPasswordMustChange],
+		ControlTypeVChuPasswordMustChange,
+		false,
+		c.MustChange)
+}
+
+// ControlVChuPasswordWarning implements the control described in https://tools.ietf.org/html/draft-vchu-ldap-pwd-policy-00
+type ControlVChuPasswordWarning struct {
+	// Expire indicates the time in seconds until the password expires
+	Expire int64
+}
+
+// GetControlType returns the OID
+func (c *ControlVChuPasswordWarning) GetControlType() string {
+	return ControlTypeVChuPasswordWarning
+}
+
+// Encode returns the ber packet representation
+func (c *ControlVChuPasswordWarning) Encode() *ber.Packet {
+	return nil
+}
+
+// String returns a human-readable description
+func (c *ControlVChuPasswordWarning) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)  Criticality: %t  Expire: %b",
+		ControlTypeMap[ControlTypeVChuPasswordWarning],
+		ControlTypeVChuPasswordWarning,
+		false,
+		c.Expire)
+}
+
+// ControlManageDsaIT implements the control described in https://tools.ietf.org/html/rfc3296
+type ControlManageDsaIT struct {
+	// Criticality indicates if this control is required
+	Criticality bool
+}
+
+// GetControlType returns the OID
+func (c *ControlManageDsaIT) GetControlType() string {
+	return ControlTypeManageDsaIT
+}
+
+// Encode returns the ber packet representation
+func (c *ControlManageDsaIT) Encode() *ber.Packet {
+	//FIXME
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
+	packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, ControlTypeManageDsaIT, "Control Type ("+ControlTypeMap[ControlTypeManageDsaIT]+")"))
+	if c.Criticality {
+		packet.AppendChild(ber.NewBoolean(ber.ClassUniversal, ber.TypePrimitive, ber.TagBoolean, c.Criticality, "Criticality"))
+	}
+	return packet
+}
+
+// String returns a human-readable description
+func (c *ControlManageDsaIT) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)  Criticality: %t",
+		ControlTypeMap[ControlTypeManageDsaIT],
+		ControlTypeManageDsaIT,
+		c.Criticality)
+}
+
+// NewControlManageDsaIT returns a ControlManageDsaIT control
+func NewControlManageDsaIT(Criticality bool) *ControlManageDsaIT {
+	return &ControlManageDsaIT{Criticality: Criticality}
+}
+
+// ControlMicrosoftNotification implements the control described in https://msdn.microsoft.com/en-us/library/aa366983(v=vs.85).aspx
+type ControlMicrosoftNotification struct{}
+
+// GetControlType returns the OID
+func (c *ControlMicrosoftNotification) GetControlType() string {
+	return ControlTypeMicrosoftNotification
+}
+
+// Encode returns the ber packet representation
+func (c *ControlMicrosoftNotification) Encode() *ber.Packet {
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
+	packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, ControlTypeMicrosoftNotification, "Control Type ("+ControlTypeMap[ControlTypeMicrosoftNotification]+")"))
+
+	return packet
+}
+
+// String returns a human-readable description
+func (c *ControlMicrosoftNotification) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)",
+		ControlTypeMap[ControlTypeMicrosoftNotification],
+		ControlTypeMicrosoftNotification)
+}
+
+// NewControlMicrosoftNotification returns a ControlMicrosoftNotification control
+func NewControlMicrosoftNotification() *ControlMicrosoftNotification {
+	return &ControlMicrosoftNotification{}
+}
+
+// ControlMicrosoftShowDeleted implements the control described in https://msdn.microsoft.com/en-us/library/aa366989(v=vs.85).aspx
+type ControlMicrosoftShowDeleted struct{}
+
+// GetControlType returns the OID
+func (c *ControlMicrosoftShowDeleted) GetControlType() string {
+	return ControlTypeMicrosoftShowDeleted
+}
+
+// Encode returns the ber packet representation
+func (c *ControlMicrosoftShowDeleted) Encode() *ber.Packet {
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Control")
+	packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, ControlTypeMicrosoftShowDeleted, "Control Type ("+ControlTypeMap[ControlTypeMicrosoftShowDeleted]+")"))
+
+	return packet
+}
+
+// String returns a human-readable description
+func (c *ControlMicrosoftShowDeleted) String() string {
+	return fmt.Sprintf(
+		"Control Type: %s (%q)",
+		ControlTypeMap[ControlTypeMicrosoftShowDeleted],
+		ControlTypeMicrosoftShowDeleted)
+}
+
+// NewControlMicrosoftShowDeleted returns a ControlMicrosoftShowDeleted control
+func NewControlMicrosoftShowDeleted() *ControlMicrosoftShowDeleted {
+	return &ControlMicrosoftShowDeleted{}
+}
+
+// FindControl returns the first control of the given type in the list, or nil
+func FindControl(controls []Control, controlType string) Control {
+	for _, c := range controls {
+		if c.GetControlType() == controlType {
+			return c
+		}
+	}
+	return nil
+}
+
+// DecodeControl returns a control read from the given packet, or nil if no recognized control can be made
+func DecodeControl(packet *ber.Packet) (Control, error) {
+	var (
+		ControlType = ""
+		Criticality = false
+		value       *ber.Packet
+	)
+
+	switch len(packet.Children) {
+	case 0:
+		// at least one child is required for control type
+		return nil, fmt.Errorf("at least one child is required for control type")
+
+	case 1:
+		// just type, no criticality or value
+		packet.Children[0].Description = "Control Type (" + ControlTypeMap[ControlType] + ")"
+		ControlType = packet.Children[0].Value.(string)
+
+	case 2:
+		packet.Children[0].Description = "Control Type (" + ControlTypeMap[ControlType] + ")"
+		ControlType = packet.Children[0].Value.(string)
+
+		// Children[1] could be criticality or value (both are optional)
+		// duck-type on whether this is a boolean
+		if _, ok := packet.Children[1].Value.(bool); ok {
+			packet.Children[1].Description = "Criticality"
+			Criticality = packet.Children[1].Value.(bool)
+		} else {
+			packet.Children[1].Description = "Control Value"
+			value = packet.Children[1]
+		}
+
+	case 3:
+		packet.Children[0].Description = "Control Type (" + ControlTypeMap[ControlType] + ")"
+		ControlType = packet.Children[0].Value.(string)
+
+		packet.Children[1].Description = "Criticality"
+		Criticality = packet.Children[1].Value.(bool)
+
+		packet.Children[2].Description = "Control Value"
+		value = packet.Children[2]
+
+	default:
+		// more than 3 children is invalid
+		return nil, fmt.Errorf("more than 3 children is invalid for controls")
+	}
+
+	switch ControlType {
+	case ControlTypeManageDsaIT:
+		return NewControlManageDsaIT(Criticality), nil
+	case ControlTypePaging:
+		value.Description += " (Paging)"
+		c := new(ControlPaging)
+		if value.Value != nil {
+			valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
+			if err != nil {
+				return nil, fmt.Errorf("failed to decode data bytes: %s", err)
+			}
+			value.Data.Truncate(0)
+			value.Value = nil
+			value.AppendChild(valueChildren)
+		}
+		value = value.Children[0]
+		value.Description = "Search Control Value"
+		value.Children[0].Description = "Paging Size"
+		value.Children[1].Description = "Cookie"
+		c.PagingSize = uint32(value.Children[0].Value.(int64))
+		c.Cookie = value.Children[1].Data.Bytes()
+		value.Children[1].Value = c.Cookie
+		return c, nil
+	case ControlTypeBeheraPasswordPolicy:
+		value.Description += " (Password Policy - Behera)"
+		c := NewControlBeheraPasswordPolicy()
+		if value.Value != nil {
+			valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
+			if err != nil {
+				return nil, fmt.Errorf("failed to decode data bytes: %s", err)
+			}
+			value.Data.Truncate(0)
+			value.Value = nil
+			value.AppendChild(valueChildren)
+		}
+
+		sequence := value.Children[0]
+
+		for _, child := range sequence.Children {
+			if child.Tag == 0 {
+				//Warning
+				warningPacket := child.Children[0]
+				packet, err := ber.DecodePacketErr(warningPacket.Data.Bytes())
+				if err != nil {
+					return nil, fmt.Errorf("failed to decode data bytes: %s", err)
+				}
+				val, ok := packet.Value.(int64)
+				if ok {
+					if warningPacket.Tag == 0 {
+						//timeBeforeExpiration
+						c.Expire = val
+						warningPacket.Value = c.Expire
+					} else if warningPacket.Tag == 1 {
+						//graceAuthNsRemaining
+						c.Grace = val
+						warningPacket.Value = c.Grace
+					}
+				}
+			} else if child.Tag == 1 {
+				// Error
+				packet, err := ber.DecodePacketErr(child.Data.Bytes())
+				if err != nil {
+					return nil, fmt.Errorf("failed to decode data bytes: %s", err)
+				}
+				val, ok := packet.Value.(int8)
+				if !ok {
+					// what to do?
+					val = -1
+				}
+				c.Error = val
+				child.Value = c.Error
+				c.ErrorString = BeheraPasswordPolicyErrorMap[c.Error]
+			}
+		}
+		return c, nil
+	case ControlTypeVChuPasswordMustChange:
+		c := &ControlVChuPasswordMustChange{MustChange: true}
+		return c, nil
+	case ControlTypeVChuPasswordWarning:
+		c := &ControlVChuPasswordWarning{Expire: -1}
+		expireStr := ber.DecodeString(value.Data.Bytes())
+
+		expire, err := strconv.ParseInt(expireStr, 10, 64)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse value as int: %s", err)
+		}
+		c.Expire = expire
+		value.Value = c.Expire
+
+		return c, nil
+	case ControlTypeMicrosoftNotification:
+		return NewControlMicrosoftNotification(), nil
+	case ControlTypeMicrosoftShowDeleted:
+		return NewControlMicrosoftShowDeleted(), nil
+	default:
+		c := new(ControlString)
+		c.ControlType = ControlType
+		c.Criticality = Criticality
+		if value != nil {
+			c.ControlValue = value.Value.(string)
+		}
+		return c, nil
+	}
+}
+
+// NewControlString returns a generic control
+func NewControlString(controlType string, criticality bool, controlValue string) *ControlString {
+	return &ControlString{
+		ControlType:  controlType,
+		Criticality:  criticality,
+		ControlValue: controlValue,
+	}
+}
+
+// NewControlPaging returns a paging control
+func NewControlPaging(pagingSize uint32) *ControlPaging {
+	return &ControlPaging{PagingSize: pagingSize}
+}
+
+// NewControlBeheraPasswordPolicy returns a ControlBeheraPasswordPolicy
+func NewControlBeheraPasswordPolicy() *ControlBeheraPasswordPolicy {
+	return &ControlBeheraPasswordPolicy{
+		Expire: -1,
+		Grace:  -1,
+		Error:  -1,
+	}
+}
+
+func encodeControls(controls []Control) *ber.Packet {
+	packet := ber.Encode(ber.ClassContext, ber.TypeConstructed, 0, nil, "Controls")
+	for _, control := range controls {
+		packet.AppendChild(control.Encode())
+	}
+	return packet
+}
diff --git a/vendor/github.com/mattermost/ldap/debug.go b/vendor/github.com/mattermost/ldap/debug.go
new file mode 100644
index 00000000..dfddd5f2
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/debug.go
@@ -0,0 +1,37 @@
+package ldap
+
+import (
+	"bytes"
+	"log"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+const LDAP_TRACE_PREFIX = "ldap-trace: "
+
+// debugging type
+//     - has a Printf method to write the debug output
+type debugging bool
+
+// Enable controls debugging mode.
+func (debug *debugging) Enable(b bool) {
+	*debug = debugging(b)
+}
+
+// Printf writes debug output.
+func (debug debugging) Printf(format string, args ...interface{}) {
+	if debug {
+		format = LDAP_TRACE_PREFIX + format
+		log.Printf(format, args...)
+	}
+}
+
+// PrintPacket dumps a packet.
+func (debug debugging) PrintPacket(packet *ber.Packet) {
+	if debug {
+		var b bytes.Buffer
+		ber.WritePacket(&b, packet)
+		textToPrint := LDAP_TRACE_PREFIX + b.String()
+		log.Printf(textToPrint)
+	}
+}
diff --git a/vendor/github.com/mattermost/ldap/del.go b/vendor/github.com/mattermost/ldap/del.go
new file mode 100644
index 00000000..49811d34
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/del.go
@@ -0,0 +1,64 @@
+//
+// https://tools.ietf.org/html/rfc4511
+//
+// DelRequest ::= [APPLICATION 10] LDAPDN
+
+package ldap
+
+import (
+	"log"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// DelRequest implements an LDAP deletion request
+type DelRequest struct {
+	// DN is the name of the directory entry to delete
+	DN string
+	// Controls hold optional controls to send with the request
+	Controls []Control
+}
+
+func (req *DelRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypePrimitive, ApplicationDelRequest, req.DN, "Del Request")
+	pkt.Data.Write([]byte(req.DN))
+
+	envelope.AppendChild(pkt)
+	if len(req.Controls) > 0 {
+		envelope.AppendChild(encodeControls(req.Controls))
+	}
+
+	return nil
+}
+
+// NewDelRequest creates a delete request for the given DN and controls
+func NewDelRequest(DN string, Controls []Control) *DelRequest {
+	return &DelRequest{
+		DN:       DN,
+		Controls: Controls,
+	}
+}
+
+// Del executes the given delete request
+func (l *Conn) Del(delRequest *DelRequest) error {
+	msgCtx, err := l.doRequest(delRequest)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return err
+	}
+
+	if packet.Children[1].Tag == ApplicationDelResponse {
+		err := GetLDAPError(packet)
+		if err != nil {
+			return err
+		}
+	} else {
+		log.Printf("Unexpected Response: %d", packet.Children[1].Tag)
+	}
+	return nil
+}
diff --git a/vendor/github.com/mattermost/ldap/dn.go b/vendor/github.com/mattermost/ldap/dn.go
new file mode 100644
index 00000000..9d32e7fa
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/dn.go
@@ -0,0 +1,247 @@
+// File contains DN parsing functionality
+//
+// https://tools.ietf.org/html/rfc4514
+//
+//   distinguishedName = [ relativeDistinguishedName
+//         *( COMMA relativeDistinguishedName ) ]
+//     relativeDistinguishedName = attributeTypeAndValue
+//         *( PLUS attributeTypeAndValue )
+//     attributeTypeAndValue = attributeType EQUALS attributeValue
+//     attributeType = descr / numericoid
+//     attributeValue = string / hexstring
+//
+//     ; The following characters are to be escaped when they appear
+//     ; in the value to be encoded: ESC, one of <escaped>, leading
+//     ; SHARP or SPACE, trailing SPACE, and NULL.
+//     string =   [ ( leadchar / pair ) [ *( stringchar / pair )
+//        ( trailchar / pair ) ] ]
+//
+//     leadchar = LUTF1 / UTFMB
+//     LUTF1 = %x01-1F / %x21 / %x24-2A / %x2D-3A /
+//        %x3D / %x3F-5B / %x5D-7F
+//
+//     trailchar  = TUTF1 / UTFMB
+//     TUTF1 = %x01-1F / %x21 / %x23-2A / %x2D-3A /
+//        %x3D / %x3F-5B / %x5D-7F
+//
+//     stringchar = SUTF1 / UTFMB
+//     SUTF1 = %x01-21 / %x23-2A / %x2D-3A /
+//        %x3D / %x3F-5B / %x5D-7F
+//
+//     pair = ESC ( ESC / special / hexpair )
+//     special = escaped / SPACE / SHARP / EQUALS
+//     escaped = DQUOTE / PLUS / COMMA / SEMI / LANGLE / RANGLE
+//     hexstring = SHARP 1*hexpair
+//     hexpair = HEX HEX
+//
+//  where the productions <descr>, <numericoid>, <COMMA>, <DQUOTE>,
+//  <EQUALS>, <ESC>, <HEX>, <LANGLE>, <NULL>, <PLUS>, <RANGLE>, <SEMI>,
+//  <SPACE>, <SHARP>, and <UTFMB> are defined in [RFC4512].
+//
+
+package ldap
+
+import (
+	"bytes"
+	enchex "encoding/hex"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/go-asn1-ber/asn1-ber"
+)
+
+// AttributeTypeAndValue represents an attributeTypeAndValue from https://tools.ietf.org/html/rfc4514
+type AttributeTypeAndValue struct {
+	// Type is the attribute type
+	Type string
+	// Value is the attribute value
+	Value string
+}
+
+// RelativeDN represents a relativeDistinguishedName from https://tools.ietf.org/html/rfc4514
+type RelativeDN struct {
+	Attributes []*AttributeTypeAndValue
+}
+
+// DN represents a distinguishedName from https://tools.ietf.org/html/rfc4514
+type DN struct {
+	RDNs []*RelativeDN
+}
+
+// ParseDN returns a distinguishedName or an error
+func ParseDN(str string) (*DN, error) {
+	dn := new(DN)
+	dn.RDNs = make([]*RelativeDN, 0)
+	rdn := new(RelativeDN)
+	rdn.Attributes = make([]*AttributeTypeAndValue, 0)
+	buffer := bytes.Buffer{}
+	attribute := new(AttributeTypeAndValue)
+	escaping := false
+
+	unescapedTrailingSpaces := 0
+	stringFromBuffer := func() string {
+		s := buffer.String()
+		s = s[0 : len(s)-unescapedTrailingSpaces]
+		buffer.Reset()
+		unescapedTrailingSpaces = 0
+		return s
+	}
+
+	for i := 0; i < len(str); i++ {
+		char := str[i]
+		switch {
+		case escaping:
+			unescapedTrailingSpaces = 0
+			escaping = false
+			switch char {
+			case ' ', '"', '#', '+', ',', ';', '<', '=', '>', '\\':
+				buffer.WriteByte(char)
+				continue
+			}
+			// Not a special character, assume hex encoded octet
+			if len(str) == i+1 {
+				return nil, errors.New("got corrupted escaped character")
+			}
+
+			dst := []byte{0}
+			n, err := enchex.Decode([]byte(dst), []byte(str[i:i+2]))
+			if err != nil {
+				return nil, fmt.Errorf("failed to decode escaped character: %s", err)
+			} else if n != 1 {
+				return nil, fmt.Errorf("expected 1 byte when un-escaping, got %d", n)
+			}
+			buffer.WriteByte(dst[0])
+			i++
+		case char == '\\':
+			unescapedTrailingSpaces = 0
+			escaping = true
+		case char == '=':
+			attribute.Type = stringFromBuffer()
+			// Special case: If the first character in the value is # the
+			// following data is BER encoded so we can just fast forward
+			// and decode.
+			if len(str) > i+1 && str[i+1] == '#' {
+				i += 2
+				index := strings.IndexAny(str[i:], ",+")
+				data := str
+				if index > 0 {
+					data = str[i : i+index]
+				} else {
+					data = str[i:]
+				}
+				rawBER, err := enchex.DecodeString(data)
+				if err != nil {
+					return nil, fmt.Errorf("failed to decode BER encoding: %s", err)
+				}
+				packet, err := ber.DecodePacketErr(rawBER)
+				if err != nil {
+					return nil, fmt.Errorf("failed to decode BER packet: %s", err)
+				}
+				buffer.WriteString(packet.Data.String())
+				i += len(data) - 1
+			}
+		case char == ',' || char == '+':
+			// We're done with this RDN or value, push it
+			if len(attribute.Type) == 0 {
+				return nil, errors.New("incomplete type, value pair")
+			}
+			attribute.Value = stringFromBuffer()
+			rdn.Attributes = append(rdn.Attributes, attribute)
+			attribute = new(AttributeTypeAndValue)
+			if char == ',' {
+				dn.RDNs = append(dn.RDNs, rdn)
+				rdn = new(RelativeDN)
+				rdn.Attributes = make([]*AttributeTypeAndValue, 0)
+			}
+		case char == ' ' && buffer.Len() == 0:
+			// ignore unescaped leading spaces
+			continue
+		default:
+			if char == ' ' {
+				// Track unescaped spaces in case they are trailing and we need to remove them
+				unescapedTrailingSpaces++
+			} else {
+				// Reset if we see a non-space char
+				unescapedTrailingSpaces = 0
+			}
+			buffer.WriteByte(char)
+		}
+	}
+	if buffer.Len() > 0 {
+		if len(attribute.Type) == 0 {
+			return nil, errors.New("DN ended with incomplete type, value pair")
+		}
+		attribute.Value = stringFromBuffer()
+		rdn.Attributes = append(rdn.Attributes, attribute)
+		dn.RDNs = append(dn.RDNs, rdn)
+	}
+	return dn, nil
+}
+
+// Equal returns true if the DNs are equal as defined by rfc4517 4.2.15 (distinguishedNameMatch).
+// Returns true if they have the same number of relative distinguished names
+// and corresponding relative distinguished names (by position) are the same.
+func (d *DN) Equal(other *DN) bool {
+	if len(d.RDNs) != len(other.RDNs) {
+		return false
+	}
+	for i := range d.RDNs {
+		if !d.RDNs[i].Equal(other.RDNs[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// AncestorOf returns true if the other DN consists of at least one RDN followed by all the RDNs of the current DN.
+// "ou=widgets,o=acme.com" is an ancestor of "ou=sprockets,ou=widgets,o=acme.com"
+// "ou=widgets,o=acme.com" is not an ancestor of "ou=sprockets,ou=widgets,o=foo.com"
+// "ou=widgets,o=acme.com" is not an ancestor of "ou=widgets,o=acme.com"
+func (d *DN) AncestorOf(other *DN) bool {
+	if len(d.RDNs) >= len(other.RDNs) {
+		return false
+	}
+	// Take the last `len(d.RDNs)` RDNs from the other DN to compare against
+	otherRDNs := other.RDNs[len(other.RDNs)-len(d.RDNs):]
+	for i := range d.RDNs {
+		if !d.RDNs[i].Equal(otherRDNs[i]) {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if the RelativeDNs are equal as defined by rfc4517 4.2.15 (distinguishedNameMatch).
+// Relative distinguished names are the same if and only if they have the same number of AttributeTypeAndValues
+// and each attribute of the first RDN is the same as the attribute of the second RDN with the same attribute type.
+// The order of attributes is not significant.
+// Case of attribute types is not significant.
+func (r *RelativeDN) Equal(other *RelativeDN) bool {
+	if len(r.Attributes) != len(other.Attributes) {
+		return false
+	}
+	return r.hasAllAttributes(other.Attributes) && other.hasAllAttributes(r.Attributes)
+}
+
+func (r *RelativeDN) hasAllAttributes(attrs []*AttributeTypeAndValue) bool {
+	for _, attr := range attrs {
+		found := false
+		for _, myattr := range r.Attributes {
+			if myattr.Equal(attr) {
+				found = true
+				break
+			}
+		}
+		if !found {
+			return false
+		}
+	}
+	return true
+}
+
+// Equal returns true if the AttributeTypeAndValue is equivalent to the specified AttributeTypeAndValue
+// Case of the attribute type is not significant
+func (a *AttributeTypeAndValue) Equal(other *AttributeTypeAndValue) bool {
+	return strings.EqualFold(a.Type, other.Type) && a.Value == other.Value
+}
diff --git a/vendor/github.com/mattermost/ldap/doc.go b/vendor/github.com/mattermost/ldap/doc.go
new file mode 100644
index 00000000..f20d39bc
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/doc.go
@@ -0,0 +1,4 @@
+/*
+Package ldap provides basic LDAP v3 functionality.
+*/
+package ldap
diff --git a/vendor/github.com/mattermost/ldap/error.go b/vendor/github.com/mattermost/ldap/error.go
new file mode 100644
index 00000000..b1fda2d8
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/error.go
@@ -0,0 +1,236 @@
+package ldap
+
+import (
+	"fmt"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// LDAP Result Codes
+const (
+	LDAPResultSuccess                            = 0
+	LDAPResultOperationsError                    = 1
+	LDAPResultProtocolError                      = 2
+	LDAPResultTimeLimitExceeded                  = 3
+	LDAPResultSizeLimitExceeded                  = 4
+	LDAPResultCompareFalse                       = 5
+	LDAPResultCompareTrue                        = 6
+	LDAPResultAuthMethodNotSupported             = 7
+	LDAPResultStrongAuthRequired                 = 8
+	LDAPResultReferral                           = 10
+	LDAPResultAdminLimitExceeded                 = 11
+	LDAPResultUnavailableCriticalExtension       = 12
+	LDAPResultConfidentialityRequired            = 13
+	LDAPResultSaslBindInProgress                 = 14
+	LDAPResultNoSuchAttribute                    = 16
+	LDAPResultUndefinedAttributeType             = 17
+	LDAPResultInappropriateMatching              = 18
+	LDAPResultConstraintViolation                = 19
+	LDAPResultAttributeOrValueExists             = 20
+	LDAPResultInvalidAttributeSyntax             = 21
+	LDAPResultNoSuchObject                       = 32
+	LDAPResultAliasProblem                       = 33
+	LDAPResultInvalidDNSyntax                    = 34
+	LDAPResultIsLeaf                             = 35
+	LDAPResultAliasDereferencingProblem          = 36
+	LDAPResultInappropriateAuthentication        = 48
+	LDAPResultInvalidCredentials                 = 49
+	LDAPResultInsufficientAccessRights           = 50
+	LDAPResultBusy                               = 51
+	LDAPResultUnavailable                        = 52
+	LDAPResultUnwillingToPerform                 = 53
+	LDAPResultLoopDetect                         = 54
+	LDAPResultSortControlMissing                 = 60
+	LDAPResultOffsetRangeError                   = 61
+	LDAPResultNamingViolation                    = 64
+	LDAPResultObjectClassViolation               = 65
+	LDAPResultNotAllowedOnNonLeaf                = 66
+	LDAPResultNotAllowedOnRDN                    = 67
+	LDAPResultEntryAlreadyExists                 = 68
+	LDAPResultObjectClassModsProhibited          = 69
+	LDAPResultResultsTooLarge                    = 70
+	LDAPResultAffectsMultipleDSAs                = 71
+	LDAPResultVirtualListViewErrorOrControlError = 76
+	LDAPResultOther                              = 80
+	LDAPResultServerDown                         = 81
+	LDAPResultLocalError                         = 82
+	LDAPResultEncodingError                      = 83
+	LDAPResultDecodingError                      = 84
+	LDAPResultTimeout                            = 85
+	LDAPResultAuthUnknown                        = 86
+	LDAPResultFilterError                        = 87
+	LDAPResultUserCanceled                       = 88
+	LDAPResultParamError                         = 89
+	LDAPResultNoMemory                           = 90
+	LDAPResultConnectError                       = 91
+	LDAPResultNotSupported                       = 92
+	LDAPResultControlNotFound                    = 93
+	LDAPResultNoResultsReturned                  = 94
+	LDAPResultMoreResultsToReturn                = 95
+	LDAPResultClientLoop                         = 96
+	LDAPResultReferralLimitExceeded              = 97
+	LDAPResultInvalidResponse                    = 100
+	LDAPResultAmbiguousResponse                  = 101
+	LDAPResultTLSNotSupported                    = 112
+	LDAPResultIntermediateResponse               = 113
+	LDAPResultUnknownType                        = 114
+	LDAPResultCanceled                           = 118
+	LDAPResultNoSuchOperation                    = 119
+	LDAPResultTooLate                            = 120
+	LDAPResultCannotCancel                       = 121
+	LDAPResultAssertionFailed                    = 122
+	LDAPResultAuthorizationDenied                = 123
+	LDAPResultSyncRefreshRequired                = 4096
+
+	ErrorNetwork            = 200
+	ErrorFilterCompile      = 201
+	ErrorFilterDecompile    = 202
+	ErrorDebugging          = 203
+	ErrorUnexpectedMessage  = 204
+	ErrorUnexpectedResponse = 205
+	ErrorEmptyPassword      = 206
+)
+
+// LDAPResultCodeMap contains string descriptions for LDAP error codes
+var LDAPResultCodeMap = map[uint16]string{
+	LDAPResultSuccess:                            "Success",
+	LDAPResultOperationsError:                    "Operations Error",
+	LDAPResultProtocolError:                      "Protocol Error",
+	LDAPResultTimeLimitExceeded:                  "Time Limit Exceeded",
+	LDAPResultSizeLimitExceeded:                  "Size Limit Exceeded",
+	LDAPResultCompareFalse:                       "Compare False",
+	LDAPResultCompareTrue:                        "Compare True",
+	LDAPResultAuthMethodNotSupported:             "Auth Method Not Supported",
+	LDAPResultStrongAuthRequired:                 "Strong Auth Required",
+	LDAPResultReferral:                           "Referral",
+	LDAPResultAdminLimitExceeded:                 "Admin Limit Exceeded",
+	LDAPResultUnavailableCriticalExtension:       "Unavailable Critical Extension",
+	LDAPResultConfidentialityRequired:            "Confidentiality Required",
+	LDAPResultSaslBindInProgress:                 "Sasl Bind In Progress",
+	LDAPResultNoSuchAttribute:                    "No Such Attribute",
+	LDAPResultUndefinedAttributeType:             "Undefined Attribute Type",
+	LDAPResultInappropriateMatching:              "Inappropriate Matching",
+	LDAPResultConstraintViolation:                "Constraint Violation",
+	LDAPResultAttributeOrValueExists:             "Attribute Or Value Exists",
+	LDAPResultInvalidAttributeSyntax:             "Invalid Attribute Syntax",
+	LDAPResultNoSuchObject:                       "No Such Object",
+	LDAPResultAliasProblem:                       "Alias Problem",
+	LDAPResultInvalidDNSyntax:                    "Invalid DN Syntax",
+	LDAPResultIsLeaf:                             "Is Leaf",
+	LDAPResultAliasDereferencingProblem:          "Alias Dereferencing Problem",
+	LDAPResultInappropriateAuthentication:        "Inappropriate Authentication",
+	LDAPResultInvalidCredentials:                 "Invalid Credentials",
+	LDAPResultInsufficientAccessRights:           "Insufficient Access Rights",
+	LDAPResultBusy:                               "Busy",
+	LDAPResultUnavailable:                        "Unavailable",
+	LDAPResultUnwillingToPerform:                 "Unwilling To Perform",
+	LDAPResultLoopDetect:                         "Loop Detect",
+	LDAPResultSortControlMissing:                 "Sort Control Missing",
+	LDAPResultOffsetRangeError:                   "Result Offset Range Error",
+	LDAPResultNamingViolation:                    "Naming Violation",
+	LDAPResultObjectClassViolation:               "Object Class Violation",
+	LDAPResultResultsTooLarge:                    "Results Too Large",
+	LDAPResultNotAllowedOnNonLeaf:                "Not Allowed On Non Leaf",
+	LDAPResultNotAllowedOnRDN:                    "Not Allowed On RDN",
+	LDAPResultEntryAlreadyExists:                 "Entry Already Exists",
+	LDAPResultObjectClassModsProhibited:          "Object Class Mods Prohibited",
+	LDAPResultAffectsMultipleDSAs:                "Affects Multiple DSAs",
+	LDAPResultVirtualListViewErrorOrControlError: "Failed because of a problem related to the virtual list view",
+	LDAPResultOther:                              "Other",
+	LDAPResultServerDown:                         "Cannot establish a connection",
+	LDAPResultLocalError:                         "An error occurred",
+	LDAPResultEncodingError:                      "LDAP encountered an error while encoding",
+	LDAPResultDecodingError:                      "LDAP encountered an error while decoding",
+	LDAPResultTimeout:                            "LDAP timeout while waiting for a response from the server",
+	LDAPResultAuthUnknown:                        "The auth method requested in a bind request is unknown",
+	LDAPResultFilterError:                        "An error occurred while encoding the given search filter",
+	LDAPResultUserCanceled:                       "The user canceled the operation",
+	LDAPResultParamError:                         "An invalid parameter was specified",
+	LDAPResultNoMemory:                           "Out of memory error",
+	LDAPResultConnectError:                       "A connection to the server could not be established",
+	LDAPResultNotSupported:                       "An attempt has been made to use a feature not supported LDAP",
+	LDAPResultControlNotFound:                    "The controls required to perform the requested operation were not found",
+	LDAPResultNoResultsReturned:                  "No results were returned from the server",
+	LDAPResultMoreResultsToReturn:                "There are more results in the chain of results",
+	LDAPResultClientLoop:                         "A loop has been detected. For example when following referrals",
+	LDAPResultReferralLimitExceeded:              "The referral hop limit has been exceeded",
+	LDAPResultCanceled:                           "Operation was canceled",
+	LDAPResultNoSuchOperation:                    "Server has no knowledge of the operation requested for cancellation",
+	LDAPResultTooLate:                            "Too late to cancel the outstanding operation",
+	LDAPResultCannotCancel:                       "The identified operation does not support cancellation or the cancel operation cannot be performed",
+	LDAPResultAssertionFailed:                    "An assertion control given in the LDAP operation evaluated to false causing the operation to not be performed",
+	LDAPResultSyncRefreshRequired:                "Refresh Required",
+	LDAPResultInvalidResponse:                    "Invalid Response",
+	LDAPResultAmbiguousResponse:                  "Ambiguous Response",
+	LDAPResultTLSNotSupported:                    "Tls Not Supported",
+	LDAPResultIntermediateResponse:               "Intermediate Response",
+	LDAPResultUnknownType:                        "Unknown Type",
+	LDAPResultAuthorizationDenied:                "Authorization Denied",
+
+	ErrorNetwork:            "Network Error",
+	ErrorFilterCompile:      "Filter Compile Error",
+	ErrorFilterDecompile:    "Filter Decompile Error",
+	ErrorDebugging:          "Debugging Error",
+	ErrorUnexpectedMessage:  "Unexpected Message",
+	ErrorUnexpectedResponse: "Unexpected Response",
+	ErrorEmptyPassword:      "Empty password not allowed by the client",
+}
+
+// Error holds LDAP error information
+type Error struct {
+	// Err is the underlying error
+	Err error
+	// ResultCode is the LDAP error code
+	ResultCode uint16
+	// MatchedDN is the matchedDN returned if any
+	MatchedDN string
+}
+
+func (e *Error) Error() string {
+	return fmt.Sprintf("LDAP Result Code %d %q: %s", e.ResultCode, LDAPResultCodeMap[e.ResultCode], e.Err.Error())
+}
+
+// GetLDAPError creates an Error out of a BER packet representing a LDAPResult
+// The return is an error object. It can be casted to a Error structure.
+// This function returns nil if resultCode in the LDAPResult sequence is success(0).
+func GetLDAPError(packet *ber.Packet) error {
+	if packet == nil {
+		return &Error{ResultCode: ErrorUnexpectedResponse, Err: fmt.Errorf("Empty packet")}
+	}
+
+	if len(packet.Children) >= 2 {
+		response := packet.Children[1]
+		if response == nil {
+			return &Error{ResultCode: ErrorUnexpectedResponse, Err: fmt.Errorf("Empty response in packet")}
+		}
+		if response.ClassType == ber.ClassApplication && response.TagType == ber.TypeConstructed && len(response.Children) >= 3 {
+			resultCode := uint16(response.Children[0].Value.(int64))
+			if resultCode == 0 { // No error
+				return nil
+			}
+			return &Error{ResultCode: resultCode, MatchedDN: response.Children[1].Value.(string),
+				Err: fmt.Errorf("%s", response.Children[2].Value.(string))}
+		}
+	}
+
+	return &Error{ResultCode: ErrorNetwork, Err: fmt.Errorf("Invalid packet format")}
+}
+
+// NewError creates an LDAP error with the given code and underlying error
+func NewError(resultCode uint16, err error) error {
+	return &Error{ResultCode: resultCode, Err: err}
+}
+
+// IsErrorWithCode returns true if the given error is an LDAP error with the given result code
+func IsErrorWithCode(err error, desiredResultCode uint16) bool {
+	if err == nil {
+		return false
+	}
+
+	serverError, ok := err.(*Error)
+	if !ok {
+		return false
+	}
+
+	return serverError.ResultCode == desiredResultCode
+}
diff --git a/vendor/github.com/mattermost/ldap/filter.go b/vendor/github.com/mattermost/ldap/filter.go
new file mode 100644
index 00000000..a3875506
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/filter.go
@@ -0,0 +1,465 @@
+package ldap
+
+import (
+	"bytes"
+	hexpac "encoding/hex"
+	"errors"
+	"fmt"
+	"strings"
+	"unicode/utf8"
+
+	"github.com/go-asn1-ber/asn1-ber"
+)
+
+// Filter choices
+const (
+	FilterAnd             = 0
+	FilterOr              = 1
+	FilterNot             = 2
+	FilterEqualityMatch   = 3
+	FilterSubstrings      = 4
+	FilterGreaterOrEqual  = 5
+	FilterLessOrEqual     = 6
+	FilterPresent         = 7
+	FilterApproxMatch     = 8
+	FilterExtensibleMatch = 9
+)
+
+// FilterMap contains human readable descriptions of Filter choices
+var FilterMap = map[uint64]string{
+	FilterAnd:             "And",
+	FilterOr:              "Or",
+	FilterNot:             "Not",
+	FilterEqualityMatch:   "Equality Match",
+	FilterSubstrings:      "Substrings",
+	FilterGreaterOrEqual:  "Greater Or Equal",
+	FilterLessOrEqual:     "Less Or Equal",
+	FilterPresent:         "Present",
+	FilterApproxMatch:     "Approx Match",
+	FilterExtensibleMatch: "Extensible Match",
+}
+
+// SubstringFilter options
+const (
+	FilterSubstringsInitial = 0
+	FilterSubstringsAny     = 1
+	FilterSubstringsFinal   = 2
+)
+
+// FilterSubstringsMap contains human readable descriptions of SubstringFilter choices
+var FilterSubstringsMap = map[uint64]string{
+	FilterSubstringsInitial: "Substrings Initial",
+	FilterSubstringsAny:     "Substrings Any",
+	FilterSubstringsFinal:   "Substrings Final",
+}
+
+// MatchingRuleAssertion choices
+const (
+	MatchingRuleAssertionMatchingRule = 1
+	MatchingRuleAssertionType         = 2
+	MatchingRuleAssertionMatchValue   = 3
+	MatchingRuleAssertionDNAttributes = 4
+)
+
+// MatchingRuleAssertionMap contains human readable descriptions of MatchingRuleAssertion choices
+var MatchingRuleAssertionMap = map[uint64]string{
+	MatchingRuleAssertionMatchingRule: "Matching Rule Assertion Matching Rule",
+	MatchingRuleAssertionType:         "Matching Rule Assertion Type",
+	MatchingRuleAssertionMatchValue:   "Matching Rule Assertion Match Value",
+	MatchingRuleAssertionDNAttributes: "Matching Rule Assertion DN Attributes",
+}
+
+// CompileFilter converts a string representation of a filter into a BER-encoded packet
+func CompileFilter(filter string) (*ber.Packet, error) {
+	if len(filter) == 0 || filter[0] != '(' {
+		return nil, NewError(ErrorFilterCompile, errors.New("ldap: filter does not start with an '('"))
+	}
+	packet, pos, err := compileFilter(filter, 1)
+	if err != nil {
+		return nil, err
+	}
+	switch {
+	case pos > len(filter):
+		return nil, NewError(ErrorFilterCompile, errors.New("ldap: unexpected end of filter"))
+	case pos < len(filter):
+		return nil, NewError(ErrorFilterCompile, errors.New("ldap: finished compiling filter with extra at end: "+fmt.Sprint(filter[pos:])))
+	}
+	return packet, nil
+}
+
+// DecompileFilter converts a packet representation of a filter into a string representation
+func DecompileFilter(packet *ber.Packet) (ret string, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = NewError(ErrorFilterDecompile, errors.New("ldap: error decompiling filter"))
+		}
+	}()
+	ret = "("
+	err = nil
+	childStr := ""
+
+	switch packet.Tag {
+	case FilterAnd:
+		ret += "&"
+		for _, child := range packet.Children {
+			childStr, err = DecompileFilter(child)
+			if err != nil {
+				return
+			}
+			ret += childStr
+		}
+	case FilterOr:
+		ret += "|"
+		for _, child := range packet.Children {
+			childStr, err = DecompileFilter(child)
+			if err != nil {
+				return
+			}
+			ret += childStr
+		}
+	case FilterNot:
+		ret += "!"
+		childStr, err = DecompileFilter(packet.Children[0])
+		if err != nil {
+			return
+		}
+		ret += childStr
+
+	case FilterSubstrings:
+		ret += ber.DecodeString(packet.Children[0].Data.Bytes())
+		ret += "="
+		for i, child := range packet.Children[1].Children {
+			if i == 0 && child.Tag != FilterSubstringsInitial {
+				ret += "*"
+			}
+			ret += EscapeFilter(ber.DecodeString(child.Data.Bytes()))
+			if child.Tag != FilterSubstringsFinal {
+				ret += "*"
+			}
+		}
+	case FilterEqualityMatch:
+		ret += ber.DecodeString(packet.Children[0].Data.Bytes())
+		ret += "="
+		ret += EscapeFilter(ber.DecodeString(packet.Children[1].Data.Bytes()))
+	case FilterGreaterOrEqual:
+		ret += ber.DecodeString(packet.Children[0].Data.Bytes())
+		ret += ">="
+		ret += EscapeFilter(ber.DecodeString(packet.Children[1].Data.Bytes()))
+	case FilterLessOrEqual:
+		ret += ber.DecodeString(packet.Children[0].Data.Bytes())
+		ret += "<="
+		ret += EscapeFilter(ber.DecodeString(packet.Children[1].Data.Bytes()))
+	case FilterPresent:
+		ret += ber.DecodeString(packet.Data.Bytes())
+		ret += "=*"
+	case FilterApproxMatch:
+		ret += ber.DecodeString(packet.Children[0].Data.Bytes())
+		ret += "~="
+		ret += EscapeFilter(ber.DecodeString(packet.Children[1].Data.Bytes()))
+	case FilterExtensibleMatch:
+		attr := ""
+		dnAttributes := false
+		matchingRule := ""
+		value := ""
+
+		for _, child := range packet.Children {
+			switch child.Tag {
+			case MatchingRuleAssertionMatchingRule:
+				matchingRule = ber.DecodeString(child.Data.Bytes())
+			case MatchingRuleAssertionType:
+				attr = ber.DecodeString(child.Data.Bytes())
+			case MatchingRuleAssertionMatchValue:
+				value = ber.DecodeString(child.Data.Bytes())
+			case MatchingRuleAssertionDNAttributes:
+				dnAttributes = child.Value.(bool)
+			}
+		}
+
+		if len(attr) > 0 {
+			ret += attr
+		}
+		if dnAttributes {
+			ret += ":dn"
+		}
+		if len(matchingRule) > 0 {
+			ret += ":"
+			ret += matchingRule
+		}
+		ret += ":="
+		ret += EscapeFilter(value)
+	}
+
+	ret += ")"
+	return
+}
+
+func compileFilterSet(filter string, pos int, parent *ber.Packet) (int, error) {
+	for pos < len(filter) && filter[pos] == '(' {
+		child, newPos, err := compileFilter(filter, pos+1)
+		if err != nil {
+			return pos, err
+		}
+		pos = newPos
+		parent.AppendChild(child)
+	}
+	if pos == len(filter) {
+		return pos, NewError(ErrorFilterCompile, errors.New("ldap: unexpected end of filter"))
+	}
+
+	return pos + 1, nil
+}
+
+func compileFilter(filter string, pos int) (*ber.Packet, int, error) {
+	var (
+		packet *ber.Packet
+		err    error
+	)
+
+	defer func() {
+		if r := recover(); r != nil {
+			err = NewError(ErrorFilterCompile, errors.New("ldap: error compiling filter"))
+		}
+	}()
+	newPos := pos
+
+	currentRune, currentWidth := utf8.DecodeRuneInString(filter[newPos:])
+
+	switch currentRune {
+	case utf8.RuneError:
+		return nil, 0, NewError(ErrorFilterCompile, fmt.Errorf("ldap: error reading rune at position %d", newPos))
+	case '(':
+		packet, newPos, err = compileFilter(filter, pos+currentWidth)
+		newPos++
+		return packet, newPos, err
+	case '&':
+		packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterAnd, nil, FilterMap[FilterAnd])
+		newPos, err = compileFilterSet(filter, pos+currentWidth, packet)
+		return packet, newPos, err
+	case '|':
+		packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterOr, nil, FilterMap[FilterOr])
+		newPos, err = compileFilterSet(filter, pos+currentWidth, packet)
+		return packet, newPos, err
+	case '!':
+		packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterNot, nil, FilterMap[FilterNot])
+		var child *ber.Packet
+		child, newPos, err = compileFilter(filter, pos+currentWidth)
+		packet.AppendChild(child)
+		return packet, newPos, err
+	default:
+		const (
+			stateReadingAttr                   = 0
+			stateReadingExtensibleMatchingRule = 1
+			stateReadingCondition              = 2
+		)
+
+		state := stateReadingAttr
+
+		attribute := ""
+		extensibleDNAttributes := false
+		extensibleMatchingRule := ""
+		condition := ""
+
+		for newPos < len(filter) {
+			remainingFilter := filter[newPos:]
+			currentRune, currentWidth = utf8.DecodeRuneInString(remainingFilter)
+			if currentRune == ')' {
+				break
+			}
+			if currentRune == utf8.RuneError {
+				return packet, newPos, NewError(ErrorFilterCompile, fmt.Errorf("ldap: error reading rune at position %d", newPos))
+			}
+
+			switch state {
+			case stateReadingAttr:
+				switch {
+				// Extensible rule, with only DN-matching
+				case currentRune == ':' && strings.HasPrefix(remainingFilter, ":dn:="):
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterExtensibleMatch, nil, FilterMap[FilterExtensibleMatch])
+					extensibleDNAttributes = true
+					state = stateReadingCondition
+					newPos += 5
+
+				// Extensible rule, with DN-matching and a matching OID
+				case currentRune == ':' && strings.HasPrefix(remainingFilter, ":dn:"):
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterExtensibleMatch, nil, FilterMap[FilterExtensibleMatch])
+					extensibleDNAttributes = true
+					state = stateReadingExtensibleMatchingRule
+					newPos += 4
+
+				// Extensible rule, with attr only
+				case currentRune == ':' && strings.HasPrefix(remainingFilter, ":="):
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterExtensibleMatch, nil, FilterMap[FilterExtensibleMatch])
+					state = stateReadingCondition
+					newPos += 2
+
+				// Extensible rule, with no DN attribute matching
+				case currentRune == ':':
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterExtensibleMatch, nil, FilterMap[FilterExtensibleMatch])
+					state = stateReadingExtensibleMatchingRule
+					newPos++
+
+				// Equality condition
+				case currentRune == '=':
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterEqualityMatch, nil, FilterMap[FilterEqualityMatch])
+					state = stateReadingCondition
+					newPos++
+
+				// Greater-than or equal
+				case currentRune == '>' && strings.HasPrefix(remainingFilter, ">="):
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterGreaterOrEqual, nil, FilterMap[FilterGreaterOrEqual])
+					state = stateReadingCondition
+					newPos += 2
+
+				// Less-than or equal
+				case currentRune == '<' && strings.HasPrefix(remainingFilter, "<="):
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterLessOrEqual, nil, FilterMap[FilterLessOrEqual])
+					state = stateReadingCondition
+					newPos += 2
+
+				// Approx
+				case currentRune == '~' && strings.HasPrefix(remainingFilter, "~="):
+					packet = ber.Encode(ber.ClassContext, ber.TypeConstructed, FilterApproxMatch, nil, FilterMap[FilterApproxMatch])
+					state = stateReadingCondition
+					newPos += 2
+
+				// Still reading the attribute name
+				default:
+					attribute += fmt.Sprintf("%c", currentRune)
+					newPos += currentWidth
+				}
+
+			case stateReadingExtensibleMatchingRule:
+				switch {
+
+				// Matching rule OID is done
+				case currentRune == ':' && strings.HasPrefix(remainingFilter, ":="):
+					state = stateReadingCondition
+					newPos += 2
+
+				// Still reading the matching rule oid
+				default:
+					extensibleMatchingRule += fmt.Sprintf("%c", currentRune)
+					newPos += currentWidth
+				}
+
+			case stateReadingCondition:
+				// append to the condition
+				condition += fmt.Sprintf("%c", currentRune)
+				newPos += currentWidth
+			}
+		}
+
+		if newPos == len(filter) {
+			err = NewError(ErrorFilterCompile, errors.New("ldap: unexpected end of filter"))
+			return packet, newPos, err
+		}
+		if packet == nil {
+			err = NewError(ErrorFilterCompile, errors.New("ldap: error parsing filter"))
+			return packet, newPos, err
+		}
+
+		switch {
+		case packet.Tag == FilterExtensibleMatch:
+			// MatchingRuleAssertion ::= SEQUENCE {
+			//         matchingRule    [1] MatchingRuleID OPTIONAL,
+			//         type            [2] AttributeDescription OPTIONAL,
+			//         matchValue      [3] AssertionValue,
+			//         dnAttributes    [4] BOOLEAN DEFAULT FALSE
+			// }
+
+			// Include the matching rule oid, if specified
+			if len(extensibleMatchingRule) > 0 {
+				packet.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, MatchingRuleAssertionMatchingRule, extensibleMatchingRule, MatchingRuleAssertionMap[MatchingRuleAssertionMatchingRule]))
+			}
+
+			// Include the attribute, if specified
+			if len(attribute) > 0 {
+				packet.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, MatchingRuleAssertionType, attribute, MatchingRuleAssertionMap[MatchingRuleAssertionType]))
+			}
+
+			// Add the value (only required child)
+			encodedString, encodeErr := escapedStringToEncodedBytes(condition)
+			if encodeErr != nil {
+				return packet, newPos, encodeErr
+			}
+			packet.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, MatchingRuleAssertionMatchValue, encodedString, MatchingRuleAssertionMap[MatchingRuleAssertionMatchValue]))
+
+			// Defaults to false, so only include in the sequence if true
+			if extensibleDNAttributes {
+				packet.AppendChild(ber.NewBoolean(ber.ClassContext, ber.TypePrimitive, MatchingRuleAssertionDNAttributes, extensibleDNAttributes, MatchingRuleAssertionMap[MatchingRuleAssertionDNAttributes]))
+			}
+
+		case packet.Tag == FilterEqualityMatch && condition == "*":
+			packet = ber.NewString(ber.ClassContext, ber.TypePrimitive, FilterPresent, attribute, FilterMap[FilterPresent])
+		case packet.Tag == FilterEqualityMatch && strings.Contains(condition, "*"):
+			packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, attribute, "Attribute"))
+			packet.Tag = FilterSubstrings
+			packet.Description = FilterMap[uint64(packet.Tag)]
+			seq := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Substrings")
+			parts := strings.Split(condition, "*")
+			for i, part := range parts {
+				if part == "" {
+					continue
+				}
+				var tag ber.Tag
+				switch i {
+				case 0:
+					tag = FilterSubstringsInitial
+				case len(parts) - 1:
+					tag = FilterSubstringsFinal
+				default:
+					tag = FilterSubstringsAny
+				}
+				encodedString, encodeErr := escapedStringToEncodedBytes(part)
+				if encodeErr != nil {
+					return packet, newPos, encodeErr
+				}
+				seq.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, tag, encodedString, FilterSubstringsMap[uint64(tag)]))
+			}
+			packet.AppendChild(seq)
+		default:
+			encodedString, encodeErr := escapedStringToEncodedBytes(condition)
+			if encodeErr != nil {
+				return packet, newPos, encodeErr
+			}
+			packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, attribute, "Attribute"))
+			packet.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, encodedString, "Condition"))
+		}
+
+		newPos += currentWidth
+		return packet, newPos, err
+	}
+}
+
+// Convert from "ABC\xx\xx\xx" form to literal bytes for transport
+func escapedStringToEncodedBytes(escapedString string) (string, error) {
+	var buffer bytes.Buffer
+	i := 0
+	for i < len(escapedString) {
+		currentRune, currentWidth := utf8.DecodeRuneInString(escapedString[i:])
+		if currentRune == utf8.RuneError {
+			return "", NewError(ErrorFilterCompile, fmt.Errorf("ldap: error reading rune at position %d", i))
+		}
+
+		// Check for escaped hex characters and convert them to their literal value for transport.
+		if currentRune == '\\' {
+			// http://tools.ietf.org/search/rfc4515
+			// \ (%x5C) is not a valid character unless it is followed by two HEX characters due to not
+			// being a member of UTF1SUBSET.
+			if i+2 > len(escapedString) {
+				return "", NewError(ErrorFilterCompile, errors.New("ldap: missing characters for escape in filter"))
+			}
+			escByte, decodeErr := hexpac.DecodeString(escapedString[i+1 : i+3])
+			if decodeErr != nil {
+				return "", NewError(ErrorFilterCompile, errors.New("ldap: invalid characters for escape in filter"))
+			}
+			buffer.WriteByte(escByte[0])
+			i += 2 // +1 from end of loop, so 3 total for \xx.
+		} else {
+			buffer.WriteRune(currentRune)
+		}
+
+		i += currentWidth
+	}
+	return buffer.String(), nil
+}
diff --git a/vendor/github.com/mattermost/ldap/go.mod b/vendor/github.com/mattermost/ldap/go.mod
new file mode 100644
index 00000000..8c15079d
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/go.mod
@@ -0,0 +1,5 @@
+module github.com/mattermost/ldap
+
+require github.com/go-asn1-ber/asn1-ber v1.3.2-0.20191121212151-29be175fc3a3
+
+go 1.13
diff --git a/vendor/github.com/mattermost/ldap/go.sum b/vendor/github.com/mattermost/ldap/go.sum
new file mode 100644
index 00000000..5eb88fee
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/go.sum
@@ -0,0 +1,4 @@
+github.com/go-asn1-ber/asn1-ber v1.3.1 h1:gvPdv/Hr++TRFCl0UbPFHC54P9N9jgsRPnmnr419Uck=
+github.com/go-asn1-ber/asn1-ber v1.3.1/go.mod h1:hEBeB/ic+5LoWskz+yKT7vGhhPYkProFKoKdwZRWMe0=
+github.com/go-asn1-ber/asn1-ber v1.3.2-0.20191121212151-29be175fc3a3 h1:QW2p25fGTu/S0MvEftCo3wV7aEFHBt2m1DTg1HUwh+o=
+github.com/go-asn1-ber/asn1-ber v1.3.2-0.20191121212151-29be175fc3a3/go.mod h1:hEBeB/ic+5LoWskz+yKT7vGhhPYkProFKoKdwZRWMe0=
diff --git a/vendor/github.com/mattermost/ldap/ldap.go b/vendor/github.com/mattermost/ldap/ldap.go
new file mode 100644
index 00000000..7dbc951a
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/ldap.go
@@ -0,0 +1,345 @@
+package ldap
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// LDAP Application Codes
+const (
+	ApplicationBindRequest           = 0
+	ApplicationBindResponse          = 1
+	ApplicationUnbindRequest         = 2
+	ApplicationSearchRequest         = 3
+	ApplicationSearchResultEntry     = 4
+	ApplicationSearchResultDone      = 5
+	ApplicationModifyRequest         = 6
+	ApplicationModifyResponse        = 7
+	ApplicationAddRequest            = 8
+	ApplicationAddResponse           = 9
+	ApplicationDelRequest            = 10
+	ApplicationDelResponse           = 11
+	ApplicationModifyDNRequest       = 12
+	ApplicationModifyDNResponse      = 13
+	ApplicationCompareRequest        = 14
+	ApplicationCompareResponse       = 15
+	ApplicationAbandonRequest        = 16
+	ApplicationSearchResultReference = 19
+	ApplicationExtendedRequest       = 23
+	ApplicationExtendedResponse      = 24
+)
+
+// ApplicationMap contains human readable descriptions of LDAP Application Codes
+var ApplicationMap = map[uint8]string{
+	ApplicationBindRequest:           "Bind Request",
+	ApplicationBindResponse:          "Bind Response",
+	ApplicationUnbindRequest:         "Unbind Request",
+	ApplicationSearchRequest:         "Search Request",
+	ApplicationSearchResultEntry:     "Search Result Entry",
+	ApplicationSearchResultDone:      "Search Result Done",
+	ApplicationModifyRequest:         "Modify Request",
+	ApplicationModifyResponse:        "Modify Response",
+	ApplicationAddRequest:            "Add Request",
+	ApplicationAddResponse:           "Add Response",
+	ApplicationDelRequest:            "Del Request",
+	ApplicationDelResponse:           "Del Response",
+	ApplicationModifyDNRequest:       "Modify DN Request",
+	ApplicationModifyDNResponse:      "Modify DN Response",
+	ApplicationCompareRequest:        "Compare Request",
+	ApplicationCompareResponse:       "Compare Response",
+	ApplicationAbandonRequest:        "Abandon Request",
+	ApplicationSearchResultReference: "Search Result Reference",
+	ApplicationExtendedRequest:       "Extended Request",
+	ApplicationExtendedResponse:      "Extended Response",
+}
+
+// Ldap Behera Password Policy Draft 10 (https://tools.ietf.org/html/draft-behera-ldap-password-policy-10)
+const (
+	BeheraPasswordExpired             = 0
+	BeheraAccountLocked               = 1
+	BeheraChangeAfterReset            = 2
+	BeheraPasswordModNotAllowed       = 3
+	BeheraMustSupplyOldPassword       = 4
+	BeheraInsufficientPasswordQuality = 5
+	BeheraPasswordTooShort            = 6
+	BeheraPasswordTooYoung            = 7
+	BeheraPasswordInHistory           = 8
+)
+
+// BeheraPasswordPolicyErrorMap contains human readable descriptions of Behera Password Policy error codes
+var BeheraPasswordPolicyErrorMap = map[int8]string{
+	BeheraPasswordExpired:             "Password expired",
+	BeheraAccountLocked:               "Account locked",
+	BeheraChangeAfterReset:            "Password must be changed",
+	BeheraPasswordModNotAllowed:       "Policy prevents password modification",
+	BeheraMustSupplyOldPassword:       "Policy requires old password in order to change password",
+	BeheraInsufficientPasswordQuality: "Password fails quality checks",
+	BeheraPasswordTooShort:            "Password is too short for policy",
+	BeheraPasswordTooYoung:            "Password has been changed too recently",
+	BeheraPasswordInHistory:           "New password is in list of old passwords",
+}
+
+// Adds descriptions to an LDAP Response packet for debugging
+func addLDAPDescriptions(packet *ber.Packet) (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = NewError(ErrorDebugging, fmt.Errorf("ldap: cannot process packet to add descriptions: %s", r))
+		}
+	}()
+	packet.Description = "LDAP Response"
+	packet.Children[0].Description = "Message ID"
+
+	application := uint8(packet.Children[1].Tag)
+	packet.Children[1].Description = ApplicationMap[application]
+
+	switch application {
+	case ApplicationBindRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationBindResponse:
+		err = addDefaultLDAPResponseDescriptions(packet)
+	case ApplicationUnbindRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationSearchRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationSearchResultEntry:
+		packet.Children[1].Children[0].Description = "Object Name"
+		packet.Children[1].Children[1].Description = "Attributes"
+		for _, child := range packet.Children[1].Children[1].Children {
+			child.Description = "Attribute"
+			child.Children[0].Description = "Attribute Name"
+			child.Children[1].Description = "Attribute Values"
+			for _, grandchild := range child.Children[1].Children {
+				grandchild.Description = "Attribute Value"
+			}
+		}
+		if len(packet.Children) == 3 {
+			err = addControlDescriptions(packet.Children[2])
+		}
+	case ApplicationSearchResultDone:
+		err = addDefaultLDAPResponseDescriptions(packet)
+	case ApplicationModifyRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationModifyResponse:
+	case ApplicationAddRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationAddResponse:
+	case ApplicationDelRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationDelResponse:
+	case ApplicationModifyDNRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationModifyDNResponse:
+	case ApplicationCompareRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationCompareResponse:
+	case ApplicationAbandonRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationSearchResultReference:
+	case ApplicationExtendedRequest:
+		err = addRequestDescriptions(packet)
+	case ApplicationExtendedResponse:
+	}
+
+	return err
+}
+
+func addControlDescriptions(packet *ber.Packet) error {
+	packet.Description = "Controls"
+	for _, child := range packet.Children {
+		var value *ber.Packet
+		controlType := ""
+		child.Description = "Control"
+		switch len(child.Children) {
+		case 0:
+			// at least one child is required for control type
+			return fmt.Errorf("at least one child is required for control type")
+
+		case 1:
+			// just type, no criticality or value
+			controlType = child.Children[0].Value.(string)
+			child.Children[0].Description = "Control Type (" + ControlTypeMap[controlType] + ")"
+
+		case 2:
+			controlType = child.Children[0].Value.(string)
+			child.Children[0].Description = "Control Type (" + ControlTypeMap[controlType] + ")"
+			// Children[1] could be criticality or value (both are optional)
+			// duck-type on whether this is a boolean
+			if _, ok := child.Children[1].Value.(bool); ok {
+				child.Children[1].Description = "Criticality"
+			} else {
+				child.Children[1].Description = "Control Value"
+				value = child.Children[1]
+			}
+
+		case 3:
+			// criticality and value present
+			controlType = child.Children[0].Value.(string)
+			child.Children[0].Description = "Control Type (" + ControlTypeMap[controlType] + ")"
+			child.Children[1].Description = "Criticality"
+			child.Children[2].Description = "Control Value"
+			value = child.Children[2]
+
+		default:
+			// more than 3 children is invalid
+			return fmt.Errorf("more than 3 children for control packet found")
+		}
+
+		if value == nil {
+			continue
+		}
+		switch controlType {
+		case ControlTypePaging:
+			value.Description += " (Paging)"
+			if value.Value != nil {
+				valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
+				if err != nil {
+					return fmt.Errorf("failed to decode data bytes: %s", err)
+				}
+				value.Data.Truncate(0)
+				value.Value = nil
+				valueChildren.Children[1].Value = valueChildren.Children[1].Data.Bytes()
+				value.AppendChild(valueChildren)
+			}
+			value.Children[0].Description = "Real Search Control Value"
+			value.Children[0].Children[0].Description = "Paging Size"
+			value.Children[0].Children[1].Description = "Cookie"
+
+		case ControlTypeBeheraPasswordPolicy:
+			value.Description += " (Password Policy - Behera Draft)"
+			if value.Value != nil {
+				valueChildren, err := ber.DecodePacketErr(value.Data.Bytes())
+				if err != nil {
+					return fmt.Errorf("failed to decode data bytes: %s", err)
+				}
+				value.Data.Truncate(0)
+				value.Value = nil
+				value.AppendChild(valueChildren)
+			}
+			sequence := value.Children[0]
+			for _, child := range sequence.Children {
+				if child.Tag == 0 {
+					//Warning
+					warningPacket := child.Children[0]
+					packet, err := ber.DecodePacketErr(warningPacket.Data.Bytes())
+					if err != nil {
+						return fmt.Errorf("failed to decode data bytes: %s", err)
+					}
+					val, ok := packet.Value.(int64)
+					if ok {
+						if warningPacket.Tag == 0 {
+							//timeBeforeExpiration
+							value.Description += " (TimeBeforeExpiration)"
+							warningPacket.Value = val
+						} else if warningPacket.Tag == 1 {
+							//graceAuthNsRemaining
+							value.Description += " (GraceAuthNsRemaining)"
+							warningPacket.Value = val
+						}
+					}
+				} else if child.Tag == 1 {
+					// Error
+					packet, err := ber.DecodePacketErr(child.Data.Bytes())
+					if err != nil {
+						return fmt.Errorf("failed to decode data bytes: %s", err)
+					}
+					val, ok := packet.Value.(int8)
+					if !ok {
+						val = -1
+					}
+					child.Description = "Error"
+					child.Value = val
+				}
+			}
+		}
+	}
+	return nil
+}
+
+func addRequestDescriptions(packet *ber.Packet) error {
+	packet.Description = "LDAP Request"
+	packet.Children[0].Description = "Message ID"
+	packet.Children[1].Description = ApplicationMap[uint8(packet.Children[1].Tag)]
+	if len(packet.Children) == 3 {
+		return addControlDescriptions(packet.Children[2])
+	}
+	return nil
+}
+
+func addDefaultLDAPResponseDescriptions(packet *ber.Packet) error {
+	resultCode := uint16(LDAPResultSuccess)
+	matchedDN := ""
+	description := "Success"
+	if err := GetLDAPError(packet); err != nil {
+		resultCode = err.(*Error).ResultCode
+		matchedDN = err.(*Error).MatchedDN
+		description = "Error Message"
+	}
+
+	packet.Children[1].Children[0].Description = "Result Code (" + LDAPResultCodeMap[resultCode] + ")"
+	packet.Children[1].Children[1].Description = "Matched DN (" + matchedDN + ")"
+	packet.Children[1].Children[2].Description = description
+	if len(packet.Children[1].Children) > 3 {
+		packet.Children[1].Children[3].Description = "Referral"
+	}
+	if len(packet.Children) == 3 {
+		return addControlDescriptions(packet.Children[2])
+	}
+	return nil
+}
+
+// DebugBinaryFile reads and prints packets from the given filename
+func DebugBinaryFile(fileName string) error {
+	file, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		return NewError(ErrorDebugging, err)
+	}
+	ber.PrintBytes(os.Stdout, file, "")
+	packet, err := ber.DecodePacketErr(file)
+	if err != nil {
+		return fmt.Errorf("failed to decode packet: %s", err)
+	}
+	if err := addLDAPDescriptions(packet); err != nil {
+		return err
+	}
+	ber.PrintPacket(packet)
+
+	return nil
+}
+
+var hex = "0123456789abcdef"
+
+func mustEscape(c byte) bool {
+	return c > 0x7f || c == '(' || c == ')' || c == '\\' || c == '*' || c == 0
+}
+
+// EscapeFilter escapes from the provided LDAP filter string the special
+// characters in the set `()*\` and those out of the range 0 < c < 0x80,
+// as defined in RFC4515.
+func EscapeFilter(filter string) string {
+	escape := 0
+	for i := 0; i < len(filter); i++ {
+		if mustEscape(filter[i]) {
+			escape++
+		}
+	}
+	if escape == 0 {
+		return filter
+	}
+	buf := make([]byte, len(filter)+escape*2)
+	for i, j := 0, 0; i < len(filter); i++ {
+		c := filter[i]
+		if mustEscape(c) {
+			buf[j+0] = '\\'
+			buf[j+1] = hex[c>>4]
+			buf[j+2] = hex[c&0xf]
+			j += 3
+		} else {
+			buf[j] = c
+			j++
+		}
+	}
+	return string(buf)
+}
diff --git a/vendor/github.com/mattermost/ldap/moddn.go b/vendor/github.com/mattermost/ldap/moddn.go
new file mode 100644
index 00000000..ca48b2b4
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/moddn.go
@@ -0,0 +1,85 @@
+// Package ldap - moddn.go contains ModifyDN functionality
+//
+// https://tools.ietf.org/html/rfc4511
+// ModifyDNRequest ::= [APPLICATION 12] SEQUENCE {
+//      entry           LDAPDN,
+//      newrdn          RelativeLDAPDN,
+//      deleteoldrdn    BOOLEAN,
+//      newSuperior     [0] LDAPDN OPTIONAL }
+//
+//
+package ldap
+
+import (
+	"log"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// ModifyDNRequest holds the request to modify a DN
+type ModifyDNRequest struct {
+	DN           string
+	NewRDN       string
+	DeleteOldRDN bool
+	NewSuperior  string
+}
+
+// NewModifyDNRequest creates a new request which can be passed to ModifyDN().
+//
+// To move an object in the tree, set the "newSup" to the new parent entry DN. Use an
+// empty string for just changing the object's RDN.
+//
+// For moving the object without renaming, the "rdn" must be the first
+// RDN of the given DN.
+//
+// A call like
+//   mdnReq := NewModifyDNRequest("uid=someone,dc=example,dc=org", "uid=newname", true, "")
+// will setup the request to just rename uid=someone,dc=example,dc=org to
+// uid=newname,dc=example,dc=org.
+func NewModifyDNRequest(dn string, rdn string, delOld bool, newSup string) *ModifyDNRequest {
+	return &ModifyDNRequest{
+		DN:           dn,
+		NewRDN:       rdn,
+		DeleteOldRDN: delOld,
+		NewSuperior:  newSup,
+	}
+}
+
+func (req *ModifyDNRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationModifyDNRequest, nil, "Modify DN Request")
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.DN, "DN"))
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.NewRDN, "New RDN"))
+	pkt.AppendChild(ber.NewBoolean(ber.ClassUniversal, ber.TypePrimitive, ber.TagBoolean, req.DeleteOldRDN, "Delete old RDN"))
+	if req.NewSuperior != "" {
+		pkt.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, req.NewSuperior, "New Superior"))
+	}
+
+	envelope.AppendChild(pkt)
+
+	return nil
+}
+
+// ModifyDN renames the given DN and optionally move to another base (when the "newSup" argument
+// to NewModifyDNRequest() is not "").
+func (l *Conn) ModifyDN(m *ModifyDNRequest) error {
+	msgCtx, err := l.doRequest(m)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return err
+	}
+
+	if packet.Children[1].Tag == ApplicationModifyDNResponse {
+		err := GetLDAPError(packet)
+		if err != nil {
+			return err
+		}
+	} else {
+		log.Printf("Unexpected Response: %d", packet.Children[1].Tag)
+	}
+	return nil
+}
diff --git a/vendor/github.com/mattermost/ldap/modify.go b/vendor/github.com/mattermost/ldap/modify.go
new file mode 100644
index 00000000..88f65c1b
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/modify.go
@@ -0,0 +1,151 @@
+// File contains Modify functionality
+//
+// https://tools.ietf.org/html/rfc4511
+//
+// ModifyRequest ::= [APPLICATION 6] SEQUENCE {
+//      object          LDAPDN,
+//      changes         SEQUENCE OF change SEQUENCE {
+//           operation       ENUMERATED {
+//                add     (0),
+//                delete  (1),
+//                replace (2),
+//                ...  },
+//           modification    PartialAttribute } }
+//
+// PartialAttribute ::= SEQUENCE {
+//      type       AttributeDescription,
+//      vals       SET OF value AttributeValue }
+//
+// AttributeDescription ::= LDAPString
+//                         -- Constrained to <attributedescription>
+//                         -- [RFC4512]
+//
+// AttributeValue ::= OCTET STRING
+//
+
+package ldap
+
+import (
+	"log"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// Change operation choices
+const (
+	AddAttribute     = 0
+	DeleteAttribute  = 1
+	ReplaceAttribute = 2
+)
+
+// PartialAttribute for a ModifyRequest as defined in https://tools.ietf.org/html/rfc4511
+type PartialAttribute struct {
+	// Type is the type of the partial attribute
+	Type string
+	// Vals are the values of the partial attribute
+	Vals []string
+}
+
+func (p *PartialAttribute) encode() *ber.Packet {
+	seq := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "PartialAttribute")
+	seq.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, p.Type, "Type"))
+	set := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSet, nil, "AttributeValue")
+	for _, value := range p.Vals {
+		set.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, value, "Vals"))
+	}
+	seq.AppendChild(set)
+	return seq
+}
+
+// Change for a ModifyRequest as defined in https://tools.ietf.org/html/rfc4511
+type Change struct {
+	// Operation is the type of change to be made
+	Operation uint
+	// Modification is the attribute to be modified
+	Modification PartialAttribute
+}
+
+func (c *Change) encode() *ber.Packet {
+	change := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Change")
+	change.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagEnumerated, uint64(c.Operation), "Operation"))
+	change.AppendChild(c.Modification.encode())
+	return change
+}
+
+// ModifyRequest as defined in https://tools.ietf.org/html/rfc4511
+type ModifyRequest struct {
+	// DN is the distinguishedName of the directory entry to modify
+	DN string
+	// Changes contain the attributes to modify
+	Changes []Change
+	// Controls hold optional controls to send with the request
+	Controls []Control
+}
+
+// Add appends the given attribute to the list of changes to be made
+func (req *ModifyRequest) Add(attrType string, attrVals []string) {
+	req.appendChange(AddAttribute, attrType, attrVals)
+}
+
+// Delete appends the given attribute to the list of changes to be made
+func (req *ModifyRequest) Delete(attrType string, attrVals []string) {
+	req.appendChange(DeleteAttribute, attrType, attrVals)
+}
+
+// Replace appends the given attribute to the list of changes to be made
+func (req *ModifyRequest) Replace(attrType string, attrVals []string) {
+	req.appendChange(ReplaceAttribute, attrType, attrVals)
+}
+
+func (req *ModifyRequest) appendChange(operation uint, attrType string, attrVals []string) {
+	req.Changes = append(req.Changes, Change{operation, PartialAttribute{Type: attrType, Vals: attrVals}})
+}
+
+func (req *ModifyRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationModifyRequest, nil, "Modify Request")
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.DN, "DN"))
+	changes := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Changes")
+	for _, change := range req.Changes {
+		changes.AppendChild(change.encode())
+	}
+	pkt.AppendChild(changes)
+
+	envelope.AppendChild(pkt)
+	if len(req.Controls) > 0 {
+		envelope.AppendChild(encodeControls(req.Controls))
+	}
+
+	return nil
+}
+
+// NewModifyRequest creates a modify request for the given DN
+func NewModifyRequest(dn string, controls []Control) *ModifyRequest {
+	return &ModifyRequest{
+		DN:       dn,
+		Controls: controls,
+	}
+}
+
+// Modify performs the ModifyRequest
+func (l *Conn) Modify(modifyRequest *ModifyRequest) error {
+	msgCtx, err := l.doRequest(modifyRequest)
+	if err != nil {
+		return err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return err
+	}
+
+	if packet.Children[1].Tag == ApplicationModifyResponse {
+		err := GetLDAPError(packet)
+		if err != nil {
+			return err
+		}
+	} else {
+		log.Printf("Unexpected Response: %d", packet.Children[1].Tag)
+	}
+	return nil
+}
diff --git a/vendor/github.com/mattermost/ldap/passwdmodify.go b/vendor/github.com/mattermost/ldap/passwdmodify.go
new file mode 100644
index 00000000..135554d9
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/passwdmodify.go
@@ -0,0 +1,131 @@
+// This file contains the password modify extended operation as specified in rfc 3062
+//
+// https://tools.ietf.org/html/rfc3062
+//
+
+package ldap
+
+import (
+	"fmt"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+const (
+	passwordModifyOID = "1.3.6.1.4.1.4203.1.11.1"
+)
+
+// PasswordModifyRequest implements the Password Modify Extended Operation as defined in https://www.ietf.org/rfc/rfc3062.txt
+type PasswordModifyRequest struct {
+	// UserIdentity is an optional string representation of the user associated with the request.
+	// This string may or may not be an LDAPDN [RFC2253].
+	// If no UserIdentity field is present, the request acts up upon the password of the user currently associated with the LDAP session
+	UserIdentity string
+	// OldPassword, if present, contains the user's current password
+	OldPassword string
+	// NewPassword, if present, contains the desired password for this user
+	NewPassword string
+}
+
+// PasswordModifyResult holds the server response to a PasswordModifyRequest
+type PasswordModifyResult struct {
+	// GeneratedPassword holds a password generated by the server, if present
+	GeneratedPassword string
+	// Referral are the returned referral
+	Referral string
+}
+
+func (req *PasswordModifyRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationExtendedRequest, nil, "Password Modify Extended Operation")
+	pkt.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, passwordModifyOID, "Extended Request Name: Password Modify OID"))
+
+	extendedRequestValue := ber.Encode(ber.ClassContext, ber.TypePrimitive, 1, nil, "Extended Request Value: Password Modify Request")
+	passwordModifyRequestValue := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Password Modify Request")
+	if req.UserIdentity != "" {
+		passwordModifyRequestValue.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 0, req.UserIdentity, "User Identity"))
+	}
+	if req.OldPassword != "" {
+		passwordModifyRequestValue.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 1, req.OldPassword, "Old Password"))
+	}
+	if req.NewPassword != "" {
+		passwordModifyRequestValue.AppendChild(ber.NewString(ber.ClassContext, ber.TypePrimitive, 2, req.NewPassword, "New Password"))
+	}
+	extendedRequestValue.AppendChild(passwordModifyRequestValue)
+
+	pkt.AppendChild(extendedRequestValue)
+
+	envelope.AppendChild(pkt)
+
+	return nil
+}
+
+// NewPasswordModifyRequest creates a new PasswordModifyRequest
+//
+// According to the RFC 3602:
+// userIdentity is a string representing the user associated with the request.
+// This string may or may not be an LDAPDN (RFC 2253).
+// If userIdentity is empty then the operation will act on the user associated
+// with the session.
+//
+// oldPassword is the current user's password, it can be empty or it can be
+// needed depending on the session user access rights (usually an administrator
+// can change a user's password without knowing the current one) and the
+// password policy (see pwdSafeModify password policy's attribute)
+//
+// newPassword is the desired user's password. If empty the server can return
+// an error or generate a new password that will be available in the
+// PasswordModifyResult.GeneratedPassword
+//
+func NewPasswordModifyRequest(userIdentity string, oldPassword string, newPassword string) *PasswordModifyRequest {
+	return &PasswordModifyRequest{
+		UserIdentity: userIdentity,
+		OldPassword:  oldPassword,
+		NewPassword:  newPassword,
+	}
+}
+
+// PasswordModify performs the modification request
+func (l *Conn) PasswordModify(passwordModifyRequest *PasswordModifyRequest) (*PasswordModifyResult, error) {
+	msgCtx, err := l.doRequest(passwordModifyRequest)
+	if err != nil {
+		return nil, err
+	}
+	defer l.finishMessage(msgCtx)
+
+	packet, err := l.readPacket(msgCtx)
+	if err != nil {
+		return nil, err
+	}
+
+	result := &PasswordModifyResult{}
+
+	if packet.Children[1].Tag == ApplicationExtendedResponse {
+		err := GetLDAPError(packet)
+		if err != nil {
+			if IsErrorWithCode(err, LDAPResultReferral) {
+				for _, child := range packet.Children[1].Children {
+					if child.Tag == 3 {
+						result.Referral = child.Children[0].Value.(string)
+					}
+				}
+			}
+			return result, err
+		}
+	} else {
+		return nil, NewError(ErrorUnexpectedResponse, fmt.Errorf("unexpected Response: %d", packet.Children[1].Tag))
+	}
+
+	extendedResponse := packet.Children[1]
+	for _, child := range extendedResponse.Children {
+		if child.Tag == 11 {
+			passwordModifyResponseValue := ber.DecodePacket(child.Data.Bytes())
+			if len(passwordModifyResponseValue.Children) == 1 {
+				if passwordModifyResponseValue.Children[0].Tag == 0 {
+					result.GeneratedPassword = ber.DecodeString(passwordModifyResponseValue.Children[0].Data.Bytes())
+				}
+			}
+		}
+	}
+
+	return result, nil
+}
diff --git a/vendor/github.com/mattermost/ldap/request.go b/vendor/github.com/mattermost/ldap/request.go
new file mode 100644
index 00000000..8c68f34a
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/request.go
@@ -0,0 +1,66 @@
+package ldap
+
+import (
+	"errors"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+var (
+	errRespChanClosed = errors.New("ldap: response channel closed")
+	errCouldNotRetMsg = errors.New("ldap: could not retrieve message")
+)
+
+type request interface {
+	appendTo(*ber.Packet) error
+}
+
+type requestFunc func(*ber.Packet) error
+
+func (f requestFunc) appendTo(p *ber.Packet) error {
+	return f(p)
+}
+
+func (l *Conn) doRequest(req request) (*messageContext, error) {
+	packet := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "LDAP Request")
+	packet.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, l.nextMessageID(), "MessageID"))
+	if err := req.appendTo(packet); err != nil {
+		return nil, err
+	}
+
+	if l.Debug {
+		l.Debug.PrintPacket(packet)
+	}
+
+	msgCtx, err := l.sendMessage(packet)
+	if err != nil {
+		return nil, err
+	}
+	l.Debug.Printf("%d: returning", msgCtx.id)
+	return msgCtx, nil
+}
+
+func (l *Conn) readPacket(msgCtx *messageContext) (*ber.Packet, error) {
+	l.Debug.Printf("%d: waiting for response", msgCtx.id)
+	packetResponse, ok := <-msgCtx.responses
+	if !ok {
+		return nil, NewError(ErrorNetwork, errRespChanClosed)
+	}
+	packet, err := packetResponse.ReadPacket()
+	l.Debug.Printf("%d: got response %p", msgCtx.id, packet)
+	if err != nil {
+		return nil, err
+	}
+
+	if packet == nil {
+		return nil, NewError(ErrorNetwork, errCouldNotRetMsg)
+	}
+
+	if l.Debug {
+		if err = addLDAPDescriptions(packet); err != nil {
+			return nil, err
+		}
+		l.Debug.PrintPacket(packet)
+	}
+	return packet, nil
+}
diff --git a/vendor/github.com/mattermost/ldap/search.go b/vendor/github.com/mattermost/ldap/search.go
new file mode 100644
index 00000000..186246c0
--- /dev/null
+++ b/vendor/github.com/mattermost/ldap/search.go
@@ -0,0 +1,425 @@
+// File contains Search functionality
+//
+// https://tools.ietf.org/html/rfc4511
+//
+//         SearchRequest ::= [APPLICATION 3] SEQUENCE {
+//              baseObject      LDAPDN,
+//              scope           ENUMERATED {
+//                   baseObject              (0),
+//                   singleLevel             (1),
+//                   wholeSubtree            (2),
+//                   ...  },
+//              derefAliases    ENUMERATED {
+//                   neverDerefAliases       (0),
+//                   derefInSearching        (1),
+//                   derefFindingBaseObj     (2),
+//                   derefAlways             (3) },
+//              sizeLimit       INTEGER (0 ..  maxInt),
+//              timeLimit       INTEGER (0 ..  maxInt),
+//              typesOnly       BOOLEAN,
+//              filter          Filter,
+//              attributes      AttributeSelection }
+//
+//         AttributeSelection ::= SEQUENCE OF selector LDAPString
+//                         -- The LDAPString is constrained to
+//                         -- <attributeSelector> in Section 4.5.1.8
+//
+//         Filter ::= CHOICE {
+//              and             [0] SET SIZE (1..MAX) OF filter Filter,
+//              or              [1] SET SIZE (1..MAX) OF filter Filter,
+//              not             [2] Filter,
+//              equalityMatch   [3] AttributeValueAssertion,
+//              substrings      [4] SubstringFilter,
+//              greaterOrEqual  [5] AttributeValueAssertion,
+//              lessOrEqual     [6] AttributeValueAssertion,
+//              present         [7] AttributeDescription,
+//              approxMatch     [8] AttributeValueAssertion,
+//              extensibleMatch [9] MatchingRuleAssertion,
+//              ...  }
+//
+//         SubstringFilter ::= SEQUENCE {
+//              type           AttributeDescription,
+//              substrings     SEQUENCE SIZE (1..MAX) OF substring CHOICE {
+//                   initial [0] AssertionValue,  -- can occur at most once
+//                   any     [1] AssertionValue,
+//                   final   [2] AssertionValue } -- can occur at most once
+//              }
+//
+//         MatchingRuleAssertion ::= SEQUENCE {
+//              matchingRule    [1] MatchingRuleId OPTIONAL,
+//              type            [2] AttributeDescription OPTIONAL,
+//              matchValue      [3] AssertionValue,
+//              dnAttributes    [4] BOOLEAN DEFAULT FALSE }
+//
+//
+
+package ldap
+
+import (
+	"errors"
+	"fmt"
+	"sort"
+	"strings"
+
+	ber "github.com/go-asn1-ber/asn1-ber"
+)
+
+// scope choices
+const (
+	ScopeBaseObject   = 0
+	ScopeSingleLevel  = 1
+	ScopeWholeSubtree = 2
+)
+
+// ScopeMap contains human readable descriptions of scope choices
+var ScopeMap = map[int]string{
+	ScopeBaseObject:   "Base Object",
+	ScopeSingleLevel:  "Single Level",
+	ScopeWholeSubtree: "Whole Subtree",
+}
+
+// derefAliases
+const (
+	NeverDerefAliases   = 0
+	DerefInSearching    = 1
+	DerefFindingBaseObj = 2
+	DerefAlways         = 3
+)
+
+// DerefMap contains human readable descriptions of derefAliases choices
+var DerefMap = map[int]string{
+	NeverDerefAliases:   "NeverDerefAliases",
+	DerefInSearching:    "DerefInSearching",
+	DerefFindingBaseObj: "DerefFindingBaseObj",
+	DerefAlways:         "DerefAlways",
+}
+
+// NewEntry returns an Entry object with the specified distinguished name and attribute key-value pairs.
+// The map of attributes is accessed in alphabetical order of the keys in order to ensure that, for the
+// same input map of attributes, the output entry will contain the same order of attributes
+func NewEntry(dn string, attributes map[string][]string) *Entry {
+	var attributeNames []string
+	for attributeName := range attributes {
+		attributeNames = append(attributeNames, attributeName)
+	}
+	sort.Strings(attributeNames)
+
+	var encodedAttributes []*EntryAttribute
+	for _, attributeName := range attributeNames {
+		encodedAttributes = append(encodedAttributes, NewEntryAttribute(attributeName, attributes[attributeName]))
+	}
+	return &Entry{
+		DN:         dn,
+		Attributes: encodedAttributes,
+	}
+}
+
+// Entry represents a single search result entry
+type Entry struct {
+	// DN is the distinguished name of the entry
+	DN string
+	// Attributes are the returned attributes for the entry
+	Attributes []*EntryAttribute
+}
+
+// GetAttributeValues returns the values for the named attribute, or an empty list
+func (e *Entry) GetAttributeValues(attribute string) []string {
+	for _, attr := range e.Attributes {
+		if attr.Name == attribute {
+			return attr.Values
+		}
+	}
+	return []string{}
+}
+
+// GetRawAttributeValues returns the byte values for the named attribute, or an empty list
+func (e *Entry) GetRawAttributeValues(attribute string) [][]byte {
+	for _, attr := range e.Attributes {
+		if attr.Name == attribute {
+			return attr.ByteValues
+		}
+	}
+	return [][]byte{}
+}
+
+// GetAttributeValue returns the first value for the named attribute, or ""
+func (e *Entry) GetAttributeValue(attribute string) string {
+	values := e.GetAttributeValues(attribute)
+	if len(values) == 0 {
+		return ""
+	}
+	return values[0]
+}
+
+// GetRawAttributeValue returns the first value for the named attribute, or an empty slice
+func (e *Entry) GetRawAttributeValue(attribute string) []byte {
+	values := e.GetRawAttributeValues(attribute)
+	if len(values) == 0 {
+		return []byte{}
+	}
+	return values[0]
+}
+
+// Print outputs a human-readable description
+func (e *Entry) Print() {
+	fmt.Printf("DN: %s\n", e.DN)
+	for _, attr := range e.Attributes {
+		attr.Print()
+	}
+}
+
+// PrettyPrint outputs a human-readable description indenting
+func (e *Entry) PrettyPrint(indent int) {
+	fmt.Printf("%sDN: %s\n", strings.Repeat(" ", indent), e.DN)
+	for _, attr := range e.Attributes {
+		attr.PrettyPrint(indent + 2)
+	}
+}
+
+// NewEntryAttribute returns a new EntryAttribute with the desired key-value pair
+func NewEntryAttribute(name string, values []string) *EntryAttribute {
+	var bytes [][]byte
+	for _, value := range values {
+		bytes = append(bytes, []byte(value))
+	}
+	return &EntryAttribute{
+		Name:       name,
+		Values:     values,
+		ByteValues: bytes,
+	}
+}
+
+// EntryAttribute holds a single attribute
+type EntryAttribute struct {
+	// Name is the name of the attribute
+	Name string
+	// Values contain the string values of the attribute
+	Values []string
+	// ByteValues contain the raw values of the attribute
+	ByteValues [][]byte
+}
+
+// Print outputs a human-readable description
+func (e *EntryAttribute) Print() {
+	fmt.Printf("%s: %s\n", e.Name, e.Values)
+}
+
+// PrettyPrint outputs a human-readable description with indenting
+func (e *EntryAttribute) PrettyPrint(indent int) {
+	fmt.Printf("%s%s: %s\n", strings.Repeat(" ", indent), e.Name, e.Values)
+}
+
+// SearchResult holds the server's response to a search request
+type SearchResult struct {
+	// Entries are the returned entries
+	Entries []*Entry
+	// Referrals are the returned referrals
+	Referrals []string
+	// Controls are the returned controls
+	Controls []Control
+}
+
+// Print outputs a human-readable description
+func (s *SearchResult) Print() {
+	for _, entry := range s.Entries {
+		entry.Print()
+	}
+}
+
+// PrettyPrint outputs a human-readable description with indenting
+func (s *SearchResult) PrettyPrint(indent int) {
+	for _, entry := range s.Entries {
+		entry.PrettyPrint(indent)
+	}
+}
+
+// SearchRequest represents a search request to send to the server
+type SearchRequest struct {
+	BaseDN       string
+	Scope        int
+	DerefAliases int
+	SizeLimit    int
+	TimeLimit    int
+	TypesOnly    bool
+	Filter       string
+	Attributes   []string
+	Controls     []Control
+}
+
+func (req *SearchRequest) appendTo(envelope *ber.Packet) error {
+	pkt := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationSearchRequest, nil, "Search Request")
+	pkt.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, req.BaseDN, "Base DN"))
+	pkt.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagEnumerated, uint64(req.Scope), "Scope"))
+	pkt.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagEnumerated, uint64(req.DerefAliases), "Deref Aliases"))
+	pkt.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, uint64(req.SizeLimit), "Size Limit"))
+	pkt.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, uint64(req.TimeLimit), "Time Limit"))
+	pkt.AppendChild(ber.NewBoolean(ber.ClassUniversal, ber.TypePrimitive, ber.TagBoolean, req.TypesOnly, "Types Only"))
+	// compile and encode filter
+	filterPacket, err := CompileFilter(req.Filter)
+	if err != nil {
+		return err
+	}
+	pkt.AppendChild(filterPacket)
+	// encode attributes
+	attributesPacket := ber.Encode(ber.ClassUniversal, ber.TypeConstructed, ber.TagSequence, nil, "Attributes")
+	for _, attribute := range req.Attributes {
+		attributesPacket.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, attribute, "Attribute"))
+	}
+	pkt.AppendChild(attributesPacket)
+
+	envelope.AppendChild(pkt)
+	if len(req.Controls) > 0 {
+		envelope.AppendChild(encodeControls(req.Controls))
+	}
+
+	return nil
+}
+
+// NewSearchRequest creates a new search request
+func NewSearchRequest(
+	BaseDN string,
+	Scope, DerefAliases, SizeLimit, TimeLimit int,
+	TypesOnly bool,
+	Filter string,
+	Attributes []string,
+	Controls []Control,
+) *SearchRequest {
+	return &SearchRequest{
+		BaseDN:       BaseDN,
+		Scope:        Scope,
+		DerefAliases: DerefAliases,
+		SizeLimit:    SizeLimit,
+		TimeLimit:    TimeLimit,
+		TypesOnly:    TypesOnly,
+		Filter:       Filter,
+		Attributes:   Attributes,
+		Controls:     Controls,
+	}
+}
+
+// SearchWithPaging accepts a search request and desired page size in order to execute LDAP queries to fulfill the
+// search request. All paged LDAP query responses will be buffered and the final result will be returned atomically.
+// The following four cases are possible given the arguments:
+//  - given SearchRequest missing a control of type ControlTypePaging: we will add one with the desired paging size
+//  - given SearchRequest contains a control of type ControlTypePaging that isn't actually a ControlPaging: fail without issuing any queries
+//  - given SearchRequest contains a control of type ControlTypePaging with pagingSize equal to the size requested: no change to the search request
+//  - given SearchRequest contains a control of type ControlTypePaging with pagingSize not equal to the size requested: fail without issuing any queries
+// A requested pagingSize of 0 is interpreted as no limit by LDAP servers.
+func (l *Conn) SearchWithPaging(searchRequest *SearchRequest, pagingSize uint32) (*SearchResult, error) {
+	var pagingControl *ControlPaging
+
+	control := FindControl(searchRequest.Controls, ControlTypePaging)
+	if control == nil {
+		pagingControl = NewControlPaging(pagingSize)
+		searchRequest.Controls = append(searchRequest.Controls, pagingControl)
+	} else {
+		castControl, ok := control.(*ControlPaging)
+		if !ok {
+			return nil, fmt.Errorf("expected paging control to be of type *ControlPaging, got %v", control)
+		}
+		if castControl.PagingSize != pagingSize {
+			return nil, fmt.Errorf("paging size given in search request (%d) conflicts with size given in search call (%d)", castControl.PagingSize, pagingSize)
+		}
+		pagingControl = castControl
+	}
+
+	searchResult := new(SearchResult)
+	for {
+		result, err := l.Search(searchRequest)
+		l.Debug.Printf("Looking for Paging Control...")
+		if err != nil {
+			return searchResult, err
+		}
+		if result == nil {
+			return searchResult, NewError(ErrorNetwork, errors.New("ldap: packet not received"))
+		}
+
+		for _, entry := range result.Entries {
+			searchResult.Entries = append(searchResult.Entries, entry)
+		}
+		for _, referral := range result.Referrals {
+			searchResult.Referrals = append(searchResult.Referrals, referral)
+		}
+		for _, control := range result.Controls {
+			searchResult.Controls = append(searchResult.Controls, control)
+		}
+
+		l.Debug.Printf("Looking for Paging Control...")
+		pagingResult := FindControl(result.Controls, ControlTypePaging)
+		if pagingResult == nil {
+			pagingControl = nil
+			l.Debug.Printf("Could not find paging control.  Breaking...")
+			break
+		}
+
+		cookie := pagingResult.(*ControlPaging).Cookie
+		if len(cookie) == 0 {
+			pagingControl = nil
+			l.Debug.Printf("Could not find cookie.  Breaking...")
+			break
+		}
+		pagingControl.SetCookie(cookie)
+	}
+
+	if pagingControl != nil {
+		l.Debug.Printf("Abandoning Paging...")
+		pagingControl.PagingSize = 0
+		l.Search(searchRequest)
+	}
+
+	return searchResult, nil
+}
+
+// Search performs the given search request
+func (l *Conn) Search(searchRequest *SearchRequest) (*SearchResult, error) {
+	msgCtx, err := l.doRequest(searchRequest)
+	if err != nil {
+		return nil, err
+	}
+	defer l.finishMessage(msgCtx)
+
+	result := &SearchResult{
+		Entries:   make([]*Entry, 0),
+		Referrals: make([]string, 0),
+		Controls:  make([]Control, 0)}
+
+	for {
+		packet, err := l.readPacket(msgCtx)
+		if err != nil {
+			return nil, err
+		}
+
+		switch packet.Children[1].Tag {
+		case 4:
+			entry := new(Entry)
+			entry.DN = packet.Children[1].Children[0].Value.(string)
+			for _, child := range packet.Children[1].Children[1].Children {
+				attr := new(EntryAttribute)
+				attr.Name = child.Children[0].Value.(string)
+				for _, value := range child.Children[1].Children {
+					attr.Values = append(attr.Values, value.Value.(string))
+					attr.ByteValues = append(attr.ByteValues, value.ByteValue)
+				}
+				entry.Attributes = append(entry.Attributes, attr)
+			}
+			result.Entries = append(result.Entries, entry)
+		case 5:
+			err := GetLDAPError(packet)
+			if err != nil {
+				return nil, err
+			}
+			if len(packet.Children) == 3 {
+				for _, child := range packet.Children[2].Children {
+					decodedChild, err := DecodeControl(child)
+					if err != nil {
+						return nil, fmt.Errorf("failed to decode child control: %s", err)
+					}
+					result.Controls = append(result.Controls, decodedChild)
+				}
+			}
+			return result, nil
+		case 19:
+			result.Referrals = append(result.Referrals, packet.Children[1].Children[0].Value.(string))
+		}
+	}
+}