-
Notifications
You must be signed in to change notification settings - Fork 4.6k
/
auth.go
150 lines (122 loc) · 3.27 KB
/
auth.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
package mtproto
import (
"context"
"crypto/rand"
"crypto/sha256"
"io"
"sync"
"v2ray.com/core/common"
)
const (
HeaderSize = 64
)
type SessionContext struct {
ConnectionType [4]byte
DataCenterID uint16
}
func DefaultSessionContext() SessionContext {
return SessionContext{
ConnectionType: [4]byte{0xef, 0xef, 0xef, 0xef},
DataCenterID: 0,
}
}
type contextKey int32
const (
sessionContextKey contextKey = iota
)
func ContextWithSessionContext(ctx context.Context, c SessionContext) context.Context {
return context.WithValue(ctx, sessionContextKey, c)
}
func SessionContextFromContext(ctx context.Context) SessionContext {
if c := ctx.Value(sessionContextKey); c != nil {
return c.(SessionContext)
}
return DefaultSessionContext()
}
type Authentication struct {
Header [HeaderSize]byte
DecodingKey [32]byte
EncodingKey [32]byte
DecodingNonce [16]byte
EncodingNonce [16]byte
}
func (a *Authentication) DataCenterID() uint16 {
x := ((int16(a.Header[61]) << 8) | int16(a.Header[60]))
if x < 0 {
x = -x
}
return uint16(x) - 1
}
func (a *Authentication) ConnectionType() [4]byte {
var x [4]byte
copy(x[:], a.Header[56:60])
return x
}
func (a *Authentication) ApplySecret(b []byte) {
a.DecodingKey = sha256.Sum256(append(a.DecodingKey[:], b...))
a.EncodingKey = sha256.Sum256(append(a.EncodingKey[:], b...))
}
func generateRandomBytes(random []byte, connType [4]byte) {
for {
common.Must2(rand.Read(random))
if random[0] == 0xef {
continue
}
val := (uint32(random[3]) << 24) | (uint32(random[2]) << 16) | (uint32(random[1]) << 8) | uint32(random[0])
if val == 0x44414548 || val == 0x54534f50 || val == 0x20544547 || val == 0x4954504f || val == 0xeeeeeeee {
continue
}
if 0x00000000 == (uint32(random[7])<<24)|(uint32(random[6])<<16)|(uint32(random[5])<<8)|uint32(random[4]) {
continue
}
copy(random[56:60], connType[:])
return
}
}
func NewAuthentication(sc SessionContext) *Authentication {
auth := getAuthenticationObject()
random := auth.Header[:]
generateRandomBytes(random, sc.ConnectionType)
copy(auth.EncodingKey[:], random[8:])
copy(auth.EncodingNonce[:], random[8+32:])
keyivInverse := Inverse(random[8 : 8+32+16])
copy(auth.DecodingKey[:], keyivInverse)
copy(auth.DecodingNonce[:], keyivInverse[32:])
return auth
}
func ReadAuthentication(reader io.Reader) (*Authentication, error) {
auth := getAuthenticationObject()
if _, err := io.ReadFull(reader, auth.Header[:]); err != nil {
putAuthenticationObject(auth)
return nil, err
}
copy(auth.DecodingKey[:], auth.Header[8:])
copy(auth.DecodingNonce[:], auth.Header[8+32:])
keyivInverse := Inverse(auth.Header[8 : 8+32+16])
copy(auth.EncodingKey[:], keyivInverse)
copy(auth.EncodingNonce[:], keyivInverse[32:])
return auth, nil
}
// Inverse returns a new byte array. It is a sequence of bytes when the input is read from end to beginning.Inverse
// Visible for testing only.
func Inverse(b []byte) []byte {
lenb := len(b)
b2 := make([]byte, lenb)
for i, v := range b {
b2[lenb-i-1] = v
}
return b2
}
var (
authPool = sync.Pool{
New: func() interface{} {
return new(Authentication)
},
}
)
func getAuthenticationObject() *Authentication {
return authPool.Get().(*Authentication)
}
func putAuthenticationObject(auth *Authentication) {
authPool.Put(auth)
}