1 package ntlmssp
2
3 import (
4 "bytes"
5 "encoding/binary"
6 "fmt"
7 )
8
9 type challengeMessageFields struct {
10 messageHeader
11 TargetName varField
12 NegotiateFlags negotiateFlags
13 ServerChallenge [8]byte
14 _ [8]byte
15 TargetInfo varField
16 }
17
18 func (m challengeMessageFields) IsValid() bool {
19 return m.messageHeader.IsValid() && m.MessageType == 2
20 }
21
22 type challengeMessage struct {
23 challengeMessageFields
24 TargetName string
25 TargetInfo map[avID][]byte
26 TargetInfoRaw []byte
27 }
28
29 func (m *challengeMessage) UnmarshalBinary(data []byte) error {
30 r := bytes.NewReader(data)
31 err := binary.Read(r, binary.LittleEndian, &m.challengeMessageFields)
32 if err != nil {
33 return err
34 }
35 if !m.challengeMessageFields.IsValid() {
36 return fmt.Errorf("Message is not a valid challenge message: %+v", m.challengeMessageFields.messageHeader)
37 }
38
39 if m.challengeMessageFields.TargetName.Len > 0 {
40 m.TargetName, err = m.challengeMessageFields.TargetName.ReadStringFrom(data, m.NegotiateFlags.Has(negotiateFlagNTLMSSPNEGOTIATEUNICODE))
41 if err != nil {
42 return err
43 }
44 }
45
46 if m.challengeMessageFields.TargetInfo.Len > 0 {
47 d, err := m.challengeMessageFields.TargetInfo.ReadFrom(data)
48 m.TargetInfoRaw = d
49 if err != nil {
50 return err
51 }
52 m.TargetInfo = make(map[avID][]byte)
53 r := bytes.NewReader(d)
54 for {
55 var id avID
56 var l uint16
57 err = binary.Read(r, binary.LittleEndian, &id)
58 if err != nil {
59 return err
60 }
61 if id == avIDMsvAvEOL {
62 break
63 }
64
65 err = binary.Read(r, binary.LittleEndian, &l)
66 if err != nil {
67 return err
68 }
69 value := make([]byte, l)
70 n, err := r.Read(value)
71 if err != nil {
72 return err
73 }
74 if n != int(l) {
75 return fmt.Errorf("Expected to read %d bytes, got only %d", l, n)
76 }
77 m.TargetInfo[id] = value
78 }
79 }
80
81 return nil
82 }
83
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