/
ntlm.go
393 lines (333 loc) · 8.31 KB
/
ntlm.go
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package ntlm
import (
"crypto/hmac"
"crypto/md5"
"crypto/rc4"
"encoding/binary"
"hash"
"hash/crc32"
"golang.org/x/crypto/md4" //nolint:staticcheck // md4 may be deprecated, but SMB still uses it
)
var zero [16]byte
var version = []byte{
0: WINDOWS_MAJOR_VERSION_10,
1: WINDOWS_MINOR_VERSION_0,
7: NTLMSSP_REVISION_W2K3,
}
const defaultFlags = NTLMSSP_NEGOTIATE_56 | NTLMSSP_NEGOTIATE_KEY_EXCH | NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY | NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_UNICODE | NTLMSSP_NEGOTIATE_VERSION
var le = binary.LittleEndian
const (
NtLmNegotiate = 0x00000001
NtLmChallenge = 0x00000002
NtLmAuthenticate = 0x00000003
)
const (
NTLMSSP_NEGOTIATE_UNICODE = 1 << iota
NTLM_NEGOTIATE_OEM
NTLMSSP_REQUEST_TARGET
_
NTLMSSP_NEGOTIATE_SIGN
NTLMSSP_NEGOTIATE_SEAL
NTLMSSP_NEGOTIATE_DATAGRAM
NTLMSSP_NEGOTIATE_LM_KEY
_
NTLMSSP_NEGOTIATE_NTLM
_
NTLMSSP_ANONYMOUS
NTLMSSP_NEGOTIATE_OEM_DOMAIN_SUPPLIED
NTLMSSP_NEGOTIATE_OEM_WORKSTATION_SUPPLIED
_
NTLMSSP_NEGOTIATE_ALWAYS_SIGN
NTLMSSP_TARGET_TYPE_DOMAIN
NTLMSSP_TARGET_TYPE_SERVER
_
NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY
NTLMSSP_NEGOTIATE_IDENTIFY
_
NTLMSSP_REQUEST_NON_NT_SESSION_KEY
NTLMSSP_NEGOTIATE_TARGET_INFO
_
NTLMSSP_NEGOTIATE_VERSION
_
_
_
NTLMSSP_NEGOTIATE_128
NTLMSSP_NEGOTIATE_KEY_EXCH
NTLMSSP_NEGOTIATE_56
)
const (
MsvAvEOL = iota
MsvAvNbComputerName
MsvAvNbDomainName
MsvAvDnsComputerName
MsvAvDnsDomainName
MsvAvDnsTreeName
MsvAvFlags
MsvAvTimestamp
MsvAvSingleHost
MsvAvTargetName
MsvAvChannelBindings
)
//nolint:unused
type addr struct {
typ uint32
val []byte
}
// channelBindings represents gss_channel_bindings_struct
//
//nolint:unused
type channelBindings struct {
InitiatorAddress addr
AcceptorAddress addr
AppData []byte
}
var signature = []byte("NTLMSSP\x00")
// Version
// 0-1: ProductMajorVersion
// 1-2: ProductMinorVersion
// 2-4: ProductBuild
// 4-7: Reserved
// 7-8: NTLMRevisionCurrent
const (
WINDOWS_MAJOR_VERSION_5 = 0x05
WINDOWS_MAJOR_VERSION_6 = 0x06
WINDOWS_MAJOR_VERSION_10 = 0x0a
)
const (
WINDOWS_MINOR_VERSION_0 = 0x00
WINDOWS_MINOR_VERSION_1 = 0x01
WINDOWS_MINOR_VERSION_2 = 0x02
WINDOWS_MINOR_VERSION_3 = 0x03
)
const (
NTLMSSP_REVISION_W2K3 = 0x0f
)
func ntowfv2(USER, password, domain []byte) []byte {
h := md4.New()
h.Write(password)
hash := h.Sum(nil)
return ntowfv2Hash(USER, hash, domain)
}
func ntowfv2Hash(USER, hash, domain []byte) []byte {
hm := hmac.New(md5.New, hash)
hm.Write(USER)
hm.Write(domain)
return hm.Sum(nil)
}
func encodeNtlmv2Response(dst []byte, h hash.Hash, serverChallenge, clientChallenge, timeStamp []byte, targetInfo encoder) {
// NTLMv2Response
// 0-16: Response
// 16-: NTLMv2ClientChallenge
ntlmv2ClientChallenge := dst[16:]
// NTLMv2ClientChallenge
// 0-1: RespType
// 1-2: HiRespType
// 2-4: _
// 4-8: _
// 8-16: TimeStamp
// 16-24: ChallengeFromClient
// 24-28: _
// 28-: AvPairs
ntlmv2ClientChallenge[0] = 1
ntlmv2ClientChallenge[1] = 1
copy(ntlmv2ClientChallenge[8:16], timeStamp)
copy(ntlmv2ClientChallenge[16:24], clientChallenge)
targetInfo.encode(ntlmv2ClientChallenge[28:])
h.Write(serverChallenge)
h.Write(ntlmv2ClientChallenge)
h.Sum(dst[:0]) // ntChallengeResponse.Response
}
type encoder interface {
size() int
encode(bs []byte)
}
type bytesEncoder []byte
func (b bytesEncoder) size() int {
return len(b)
}
func (b bytesEncoder) encode(bs []byte) {
copy(bs, b)
}
type targetInfoEncoder struct {
Info []byte
SPN []byte
InfoMap map[uint16][]byte
}
func newTargetInfoEncoder(info, spn []byte) *targetInfoEncoder {
infoMap, ok := parseAvPairs(info)
if !ok {
return nil
}
return &targetInfoEncoder{
Info: info,
SPN: spn,
InfoMap: infoMap,
}
}
func (i *targetInfoEncoder) size() int {
size := len(i.Info)
if _, ok := i.InfoMap[MsvAvFlags]; !ok {
size += 8
}
size += 20
if len(i.SPN) != 0 {
size += 4 + len(i.SPN)
}
return size
}
func (i *targetInfoEncoder) encode(dst []byte) {
var off int
if flags, ok := i.InfoMap[MsvAvFlags]; ok {
le.PutUint32(flags, le.Uint32(flags)|0x02)
off = copy(dst, i.Info[:len(i.Info)-4])
} else {
off = copy(dst, i.Info[:len(i.Info)-4])
le.PutUint16(dst[off:off+2], MsvAvFlags)
le.PutUint16(dst[off+2:off+4], 4)
le.PutUint32(dst[off+4:off+8], 0x02)
off += 8
}
le.PutUint16(dst[off:off+2], MsvAvChannelBindings)
le.PutUint16(dst[off+2:off+4], 16)
off += 20
if len(i.SPN) != 0 {
le.PutUint16(dst[off:off+2], MsvAvTargetName)
le.PutUint16(dst[off+2:off+4], uint16(len(i.SPN)))
copy(dst[off+4:], i.SPN)
off += 4 + len(i.SPN)
}
le.PutUint16(dst[off:off+2], MsvAvEOL)
le.PutUint16(dst[off+2:off+4], 0)
//nolint:ineffassign // we know that this does nothing, it will be removed in a later cleanup
off += 4
}
func mac(dst []byte, negotiateFlags uint32, handle *rc4.Cipher, signingKey []byte, seqNum uint32, msg []byte) ([]byte, uint32) {
ret, tag := sliceForAppend(dst, 16)
if negotiateFlags&NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY == 0 {
// NtlmsspMessageSignature
// 0-4: Version
// 4-8: RandomPad
// 8-12: Checksum
// 12-16: SeqNum
le.PutUint32(tag[:4], 0x00000001)
le.PutUint32(tag[8:12], crc32.ChecksumIEEE(msg))
handle.XORKeyStream(tag[4:8], tag[4:8])
handle.XORKeyStream(tag[8:12], tag[8:12])
handle.XORKeyStream(tag[12:16], tag[12:16])
tag[12] ^= byte(seqNum)
tag[13] ^= byte(seqNum >> 8)
tag[14] ^= byte(seqNum >> 16)
tag[15] ^= byte(seqNum >> 24)
if negotiateFlags&NTLMSSP_NEGOTIATE_DATAGRAM == 0 {
seqNum++
}
tag[4] = 0
tag[5] = 0
tag[6] = 0
tag[7] = 0
} else {
// NtlmsspMessageSignatureExt
// 0-4: Version
// 4-12: Checksum
// 12-16: SeqNum
le.PutUint32(tag[:4], 0x00000001)
le.PutUint32(tag[12:16], seqNum)
h := hmac.New(md5.New, signingKey)
h.Write(tag[12:16])
h.Write(msg)
copy(tag[4:12], h.Sum(nil))
if negotiateFlags&NTLMSSP_NEGOTIATE_KEY_EXCH != 0 {
handle.XORKeyStream(tag[4:12], tag[4:12])
}
seqNum++
}
return ret, seqNum
}
func signKey(negotiateFlags uint32, randomSessionKey []byte, fromClient bool) []byte {
if negotiateFlags&NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY != 0 {
h := md5.New()
h.Write(randomSessionKey)
if fromClient {
h.Write([]byte("session key to client-to-server signing key magic constant\x00"))
} else {
h.Write([]byte("session key to server-to-client signing key magic constant\x00"))
}
return h.Sum(nil)
}
return nil
}
func sealKey(negotiateFlags uint32, randomSessionKey []byte, fromClient bool) []byte {
if negotiateFlags&NTLMSSP_NEGOTIATE_EXTENDED_SESSIONSECURITY != 0 {
h := md5.New()
switch {
case negotiateFlags&NTLMSSP_NEGOTIATE_128 != 0:
h.Write(randomSessionKey)
case negotiateFlags&NTLMSSP_NEGOTIATE_56 != 0:
h.Write(randomSessionKey[:7])
default:
h.Write(randomSessionKey[:5])
}
if fromClient {
h.Write([]byte("session key to client-to-server sealing key magic constant\x00"))
} else {
h.Write([]byte("session key to server-to-client sealing key magic constant\x00"))
}
return h.Sum(nil)
}
if negotiateFlags&NTLMSSP_NEGOTIATE_LM_KEY != 0 {
sealingKey := make([]byte, 8)
if negotiateFlags&NTLMSSP_NEGOTIATE_56 != 0 {
copy(sealingKey, randomSessionKey[:7])
sealingKey[7] = 0xa0
} else {
copy(sealingKey, randomSessionKey[:5])
sealingKey[5] = 0xe5
sealingKey[6] = 0x38
sealingKey[7] = 0xb0
}
return sealingKey
}
return randomSessionKey
}
func parseAvPairs(bs []byte) (pairs map[uint16][]byte, ok bool) {
// AvPair
// 0-2: AvId
// 2-4: AvLen
// 4-: Value
if len(bs) < 4 {
return nil, false
}
// check MsvAvEOL
for _, c := range bs[len(bs)-4:] {
if c != 0x00 {
return nil, false
}
}
pairs = make(map[uint16][]byte)
for len(bs) > 0 {
if len(bs) < 4 {
return nil, false
}
id := le.Uint16(bs[:2])
// if _, dup := pairs[id]; dup {
// return nil, false
// }
n := int(le.Uint16(bs[2:4]))
if len(bs) < 4+n {
return nil, false
}
pairs[id] = bs[4 : 4+n]
bs = bs[4+n:]
}
return pairs, true
}
func sliceForAppend(in []byte, n int) (head, tail []byte) {
if total := len(in) + n; cap(in) >= total {
head = in[:total]
} else {
head = make([]byte, total)
copy(head, in)
}
tail = head[len(in):]
return
}