Skip to content

Adding NTLMSSP support #265

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 5 commits into from
Jun 18, 2020
Merged

Adding NTLMSSP support #265

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
f460221
added ntlm bind
Jun 7, 2020
e6e8f72
Merge branch 'master' into add_ntlm_bind
johnweldon Jun 11, 2020
580834d
adding doc comments
Jun 17, 2020
12b3050
copy changes to older version
Jun 17, 2020
c69983d
Merge branch 'master' into add_ntlm_bind
ropnop Jun 18, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
131 changes: 131 additions & 0 deletions bind.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,8 @@ import (
"strings"

ber "github.com/go-asn1-ber/asn1-ber"
"github.com/Azure/go-ntlmssp"

)

// SimpleBindRequest represents a username/password bind operation
Expand Down Expand Up @@ -387,3 +389,132 @@ func (l *Conn) ExternalBind() error {

return GetLDAPError(packet)
}

// NTLMBind performs an NTLMSSP bind leveraging https://github.com/Azure/go-ntlmssp

// NTLMBindRequest represents an NTLMSSP bind operation
type NTLMBindRequest struct {
// Domain is the AD Domain to authenticate too. If not specified, it will be grabbed from the NTLMSSP Challenge
Domain string
// 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
}

func (req *NTLMBindRequest) appendTo(envelope *ber.Packet) error {
request := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationBindRequest, nil, "Bind Request")
request.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
request.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "User Name"))

// generate an NTLMSSP Negotiation message for the specified domain (it can be blank)
negMessage, err := ntlmssp.NewNegotiateMessage(req.Domain, "")
if err != nil {
return fmt.Errorf("err creating negmessage: %s", err)
}

// append the generated NTLMSSP message as a TagEnumerated BER value
auth := ber.Encode(ber.ClassContext, ber.TypePrimitive, ber.TagEnumerated, negMessage, "authentication")
request.AppendChild(auth)
envelope.AppendChild(request)
if len(req.Controls) > 0 {
envelope.AppendChild(encodeControls(req.Controls))
}
return nil
}

// NTLMBindResult contains the response from the server
type NTLMBindResult struct {
Controls []Control
}

// NTLMBind performs an NTLMSSP Bind with the given domain, username and password
func (l *Conn) NTLMBind(domain, username, password string) error {
req := &NTLMBindRequest{
Domain: domain,
Username: username,
Password: password,
}
_, err := l.NTLMChallengeBind(req)
return err
}

// NTLMChallengeBind performs the NTLMSSP bind operation defined in the given request
func (l *Conn) NTLMChallengeBind(ntlmBindRequest *NTLMBindRequest) (*NTLMBindResult, error) {
if ntlmBindRequest.Password == "" {
return nil, NewError(ErrorEmptyPassword, errors.New("ldap: empty password not allowed by the client"))
}

msgCtx, err := l.doRequest(ntlmBindRequest)
if err != nil {
return nil, err
}
defer l.finishMessage(msgCtx)
packet, err := l.readPacket(msgCtx)
if err != nil {
return nil, err
}
l.Debug.Printf("%d: got response %p", msgCtx.id, packet)
if l.Debug {
if err = addLDAPDescriptions(packet); err != nil {
return nil, err
}
ber.PrintPacket(packet)
}
result := &NTLMBindResult{
Controls: make([]Control, 0),
}
var ntlmsspChallenge []byte

// now find the NTLM Response Message
if len(packet.Children) == 2 {
if len(packet.Children[1].Children) == 3 {
child := packet.Children[1].Children[1]
ntlmsspChallenge = child.ByteValue
// Check to make sure we got the right message. It will always start with NTLMSSP
if !bytes.Equal(ntlmsspChallenge[:7], []byte("NTLMSSP")) {
return result, GetLDAPError(packet)
}
l.Debug.Printf("%d: found ntlmssp challenge", msgCtx.id)
}
}
if ntlmsspChallenge != nil {
// generate a response message to the challenge with the given Username/Password
responseMessage, err := ntlmssp.ProcessChallenge(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Password)
if err != nil {
return result, fmt.Errorf("parsing ntlm-challenge: %s", err)
}
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, ApplicationBindRequest, nil, "Bind Request")
request.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
request.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "User Name"))

// append the challenge response message as a TagEmbeddedPDV BER value
auth := ber.Encode(ber.ClassContext, ber.TypePrimitive, ber.TagEmbeddedPDV, responseMessage, "authentication")

request.AppendChild(auth)
packet.AppendChild(request)
msgCtx, err = l.sendMessage(packet)
if err != nil {
return nil, fmt.Errorf("send message: %s", err)
}
defer l.finishMessage(msgCtx)
packetResponse, ok := <-msgCtx.responses
if !ok {
return nil, 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 nil, fmt.Errorf("read packet: %s", err)
}

}

err = GetLDAPError(packet)
return result, err
}
131 changes: 131 additions & 0 deletions v3/bind.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,8 @@ import (
"strings"

ber "github.com/go-asn1-ber/asn1-ber"
"github.com/Azure/go-ntlmssp"

)

// SimpleBindRequest represents a username/password bind operation
Expand Down Expand Up @@ -387,3 +389,132 @@ func (l *Conn) ExternalBind() error {

return GetLDAPError(packet)
}

// NTLMBind performs an NTLMSSP bind leveraging https://github.com/Azure/go-ntlmssp

// NTLMBindRequest represents an NTLMSSP bind operation
type NTLMBindRequest struct {
// Domain is the AD Domain to authenticate too. If not specified, it will be grabbed from the NTLMSSP Challenge
Domain string
// 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
}

func (req *NTLMBindRequest) appendTo(envelope *ber.Packet) error {
request := ber.Encode(ber.ClassApplication, ber.TypeConstructed, ApplicationBindRequest, nil, "Bind Request")
request.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
request.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "User Name"))

// generate an NTLMSSP Negotiation message for the specified domain (it can be blank)
negMessage, err := ntlmssp.NewNegotiateMessage(req.Domain, "")
if err != nil {
return fmt.Errorf("err creating negmessage: %s", err)
}

// append the generated NTLMSSP message as a TagEnumerated BER value
auth := ber.Encode(ber.ClassContext, ber.TypePrimitive, ber.TagEnumerated, negMessage, "authentication")
request.AppendChild(auth)
envelope.AppendChild(request)
if len(req.Controls) > 0 {
envelope.AppendChild(encodeControls(req.Controls))
}
return nil
}

// NTLMBindResult contains the response from the server
type NTLMBindResult struct {
Controls []Control
}

// NTLMBind performs an NTLMSSP Bind with the given domain, username and password
func (l *Conn) NTLMBind(domain, username, password string) error {
req := &NTLMBindRequest{
Domain: domain,
Username: username,
Password: password,
}
_, err := l.NTLMChallengeBind(req)
return err
}

// NTLMChallengeBind performs the NTLMSSP bind operation defined in the given request
func (l *Conn) NTLMChallengeBind(ntlmBindRequest *NTLMBindRequest) (*NTLMBindResult, error) {
if ntlmBindRequest.Password == "" {
return nil, NewError(ErrorEmptyPassword, errors.New("ldap: empty password not allowed by the client"))
}

msgCtx, err := l.doRequest(ntlmBindRequest)
if err != nil {
return nil, err
}
defer l.finishMessage(msgCtx)
packet, err := l.readPacket(msgCtx)
if err != nil {
return nil, err
}
l.Debug.Printf("%d: got response %p", msgCtx.id, packet)
if l.Debug {
if err = addLDAPDescriptions(packet); err != nil {
return nil, err
}
ber.PrintPacket(packet)
}
result := &NTLMBindResult{
Controls: make([]Control, 0),
}
var ntlmsspChallenge []byte

// now find the NTLM Response Message
if len(packet.Children) == 2 {
if len(packet.Children[1].Children) == 3 {
child := packet.Children[1].Children[1]
ntlmsspChallenge = child.ByteValue
// Check to make sure we got the right message. It will always start with NTLMSSP
if !bytes.Equal(ntlmsspChallenge[:7], []byte("NTLMSSP")) {
return result, GetLDAPError(packet)
}
l.Debug.Printf("%d: found ntlmssp challenge", msgCtx.id)
}
}
if ntlmsspChallenge != nil {
// generate a response message to the challenge with the given Username/Password
responseMessage, err := ntlmssp.ProcessChallenge(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Password)
if err != nil {
return result, fmt.Errorf("parsing ntlm-challenge: %s", err)
}
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, ApplicationBindRequest, nil, "Bind Request")
request.AppendChild(ber.NewInteger(ber.ClassUniversal, ber.TypePrimitive, ber.TagInteger, 3, "Version"))
request.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "", "User Name"))

// append the challenge response message as a TagEmbeddedPDV BER value
auth := ber.Encode(ber.ClassContext, ber.TypePrimitive, ber.TagEmbeddedPDV, responseMessage, "authentication")

request.AppendChild(auth)
packet.AppendChild(request)
msgCtx, err = l.sendMessage(packet)
if err != nil {
return nil, fmt.Errorf("send message: %s", err)
}
defer l.finishMessage(msgCtx)
packetResponse, ok := <-msgCtx.responses
if !ok {
return nil, 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 nil, fmt.Errorf("read packet: %s", err)
}

}

err = GetLDAPError(packet)
return result, err
}