forked from Azure/go-ntlmssp
/
challenge_message.go
94 lines (83 loc) · 2.49 KB
/
challenge_message.go
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package ntlmssp
import (
"bytes"
"encoding/binary"
"fmt"
"strings"
)
type challengeMessageFields struct {
messageHeader
TargetName varField
NegotiateFlags negotiateFlags
ServerChallenge [8]byte
_ [8]byte
TargetInfo varField
}
func (m challengeMessageFields) IsValid() bool {
return m.messageHeader.IsValid() && m.MessageType == 2
}
type challengeMessage struct {
challengeMessageFields
TargetName string
TargetInfo map[avID][]byte
TargetInfoRaw []byte
}
func (m *challengeMessage) UnmarshalBinary(data []byte) error {
r := bytes.NewReader(data)
err := binary.Read(r, binary.LittleEndian, &m.challengeMessageFields)
if err != nil {
return err
}
if !m.challengeMessageFields.IsValid() {
return fmt.Errorf("message is not a valid challenge message: %+v", m.challengeMessageFields.messageHeader)
}
if m.challengeMessageFields.TargetName.Len > 0 {
m.TargetName, err = m.challengeMessageFields.TargetName.ReadStringFrom(data, m.NegotiateFlags.Has(FlagNTLMSSPNEGOTIATEUNICODE))
if err != nil {
return err
}
}
if m.challengeMessageFields.TargetInfo.Len > 0 {
d, err := m.challengeMessageFields.TargetInfo.ReadFrom(data)
m.TargetInfoRaw = d
if err != nil {
return err
}
m.TargetInfo = make(map[avID][]byte)
r := bytes.NewReader(d)
for {
var id avID
var l uint16
err = binary.Read(r, binary.LittleEndian, &id)
if err != nil {
return err
}
if id == avIDMsvAvEOL {
break
}
err = binary.Read(r, binary.LittleEndian, &l)
if err != nil {
return err
}
value := make([]byte, l)
n, err := r.Read(value)
if err != nil {
return err
}
if n != int(l) {
return fmt.Errorf("expected to read %d bytes, got only %d", l, n)
}
m.TargetInfo[id] = value
}
}
return nil
}
func (m *challengeMessage) String() string {
sb := strings.Builder{}
sb.WriteString(fmt.Sprintf("%s (%x)\n", m.TargetName, m.NegotiateFlags))
sb.WriteString(fmt.Sprintf("%d - %v\n", m.MessageType, m.Signature))
for k, v := range m.TargetInfo {
sb.WriteString(fmt.Sprintf("\t%d: %s\n", k, string(v)))
}
return sb.String()
}