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

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package ldap
import (
"bytes"
"crypto/md5"
enchex "encoding/hex"
"errors"
"fmt"
"io/ioutil"
"math/rand"
"strings"
"github.com/Azure/go-ntlmssp"
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
}
// DigestMD5BindRequest represents a digest-md5 bind operation
type DigestMD5BindRequest struct {
Host 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 *DigestMD5BindRequest) 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"))
auth := ber.Encode(ber.ClassContext, ber.TypeConstructed, 3, "", "authentication")
auth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "DIGEST-MD5", "SASL Mech"))
request.AppendChild(auth)
envelope.AppendChild(request)
if len(req.Controls) > 0 {
envelope.AppendChild(encodeControls(req.Controls))
}
return nil
}
// DigestMD5BindResult contains the response from the server
type DigestMD5BindResult struct {
Controls []Control
}
// MD5Bind performs a digest-md5 bind with the given host, username and password.
func (l *Conn) MD5Bind(host, username, password string) error {
req := &DigestMD5BindRequest{
Host: host,
Username: username,
Password: password,
}
_, err := l.DigestMD5Bind(req)
return err
}
// DigestMD5Bind performs the digest-md5 bind operation defined in the given request
func (l *Conn) DigestMD5Bind(digestMD5BindRequest *DigestMD5BindRequest) (*DigestMD5BindResult, error) {
if digestMD5BindRequest.Password == "" {
return nil, NewError(ErrorEmptyPassword, errors.New("ldap: empty password not allowed by the client"))
}
msgCtx, err := l.doRequest(digestMD5BindRequest)
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 := &DigestMD5BindResult{
Controls: make([]Control, 0),
}
var params map[string]string
if len(packet.Children) == 2 {
if len(packet.Children[1].Children) == 4 {
child := packet.Children[1].Children[0]
if child.Tag != ber.TagEnumerated {
return result, GetLDAPError(packet)
}
if child.Value.(int64) != 14 {
return result, GetLDAPError(packet)
}
child = packet.Children[1].Children[3]
if child.Tag != ber.TagObjectDescriptor {
return result, GetLDAPError(packet)
}
if child.Data == nil {
return result, GetLDAPError(packet)
}
data, _ := ioutil.ReadAll(child.Data)
params, err = parseParams(string(data))
if err != nil {
return result, fmt.Errorf("parsing digest-challenge: %s", err)
}
}
}
if params != nil {
resp := computeResponse(
params,
"ldap/"+strings.ToLower(digestMD5BindRequest.Host),
digestMD5BindRequest.Username,
digestMD5BindRequest.Password,
)
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"))
auth := ber.Encode(ber.ClassContext, ber.TypeConstructed, 3, "", "authentication")
auth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, "DIGEST-MD5", "SASL Mech"))
auth.AppendChild(ber.NewString(ber.ClassUniversal, ber.TypePrimitive, ber.TagOctetString, resp, "Credentials"))
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
}
func parseParams(str string) (map[string]string, error) {
m := make(map[string]string)
var key, value string
var state int
for i := 0; i <= len(str); i++ {
switch state {
case 0: //reading key
if i == len(str) {
return nil, fmt.Errorf("syntax error on %d", i)
}
if str[i] != '=' {
key += string(str[i])
continue
}
state = 1
case 1: //reading value
if i == len(str) {
m[key] = value
break
}
switch str[i] {
case ',':
m[key] = value
state = 0
key = ""
value = ""
case '"':
if value != "" {
return nil, fmt.Errorf("syntax error on %d", i)
}
state = 2
default:
value += string(str[i])
}
case 2: //inside quotes
if i == len(str) {
return nil, fmt.Errorf("syntax error on %d", i)
}
if str[i] != '"' {
value += string(str[i])
} else {
state = 1
}
}
}
return m, nil
}
func computeResponse(params map[string]string, uri, username, password string) string {
nc := "00000001"
qop := "auth"
cnonce := enchex.EncodeToString(randomBytes(16))
x := username + ":" + params["realm"] + ":" + password
y := md5Hash([]byte(x))
a1 := bytes.NewBuffer(y)
a1.WriteString(":" + params["nonce"] + ":" + cnonce)
if len(params["authzid"]) > 0 {
a1.WriteString(":" + params["authzid"])
}
a2 := bytes.NewBuffer([]byte("AUTHENTICATE"))
a2.WriteString(":" + uri)
ha1 := enchex.EncodeToString(md5Hash(a1.Bytes()))
ha2 := enchex.EncodeToString(md5Hash(a2.Bytes()))
kd := ha1
kd += ":" + params["nonce"]
kd += ":" + nc
kd += ":" + cnonce
kd += ":" + qop
kd += ":" + ha2
resp := enchex.EncodeToString(md5Hash([]byte(kd)))
return fmt.Sprintf(
`username="%s",realm="%s",nonce="%s",cnonce="%s",nc=00000001,qop=%s,digest-uri="%s",response=%s`,
username,
params["realm"],
params["nonce"],
cnonce,
qop,
uri,
resp,
)
}
func md5Hash(b []byte) []byte {
hasher := md5.New()
hasher.Write(b)
return hasher.Sum(nil)
}
func randomBytes(len int) []byte {
b := make([]byte, len)
for i := 0; i < len; i++ {
b[i] = byte(rand.Intn(256))
}
return b
}
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)
}
// 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
// Hash is the hex NTLM hash to bind with. Password or hash must be provided
Hash string
// Controls are optional controls to send with the bind request
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
}
// NTLMBindWithHash performs an NTLM Bind with an NTLM hash instead of plaintext password (pass-the-hash)
func (l *Conn) NTLMBindWithHash(domain, username, hash string) error {
req := &NTLMBindRequest{
Domain: domain,
Username: username,
Hash: hash,
}
_, 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 == "" && ntlmBindRequest.Hash == "" {
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 {
var err error
var responseMessage []byte
// generate a response message to the challenge with the given Username/Password if password is provided
if ntlmBindRequest.Password != "" {
responseMessage, err = ntlmssp.ProcessChallenge(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Password)
} else if ntlmBindRequest.Hash != "" {
responseMessage, err = ntlmssp.ProcessChallengeWithHash(ntlmsspChallenge, ntlmBindRequest.Username, ntlmBindRequest.Hash)
} else {
err = fmt.Errorf("need a password or hash to generate reply")
}
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
}