aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/contrib/external-tests/go/main.go
blob: a52f16e0826dbbd6d37f462dc6b70dc6b862eabe (plain) (blame)
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
/* Copyright (C) 2015-2020 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */

package main

import (
	"crypto/rand"
	"encoding/base64"
	"encoding/binary"
	"log"
	"net"
	"time"

	"github.com/titanous/noise"
	"golang.org/x/net/icmp"
	"golang.org/x/net/ipv4"
	"golang.org/x/crypto/blake2s"
)

func ipChecksum(buf []byte) uint16 {
	sum := uint32(0)
	for ; len(buf) >= 2; buf = buf[2:] {
		sum += uint32(buf[0])<<8 | uint32(buf[1])
	}
	if len(buf) > 0 {
		sum += uint32(buf[0]) << 8
	}
	for sum > 0xffff {
		sum = (sum >> 16) + (sum & 0xffff)
	}
	csum := ^uint16(sum)
	if csum == 0 {
		csum = 0xffff
	}
	return csum
}

func main() {
	ourPrivate, _ := base64.StdEncoding.DecodeString("WAmgVYXkbT2bCtdcDwolI88/iVi/aV3/PHcUBTQSYmo=")
	ourPublic, _ := base64.StdEncoding.DecodeString("K5sF9yESrSBsOXPd6TcpKNgqoy1Ik3ZFKl4FolzrRyI=")
	theirPublic, _ := base64.StdEncoding.DecodeString("qRCwZSKInrMAq5sepfCdaCsRJaoLe5jhtzfiw7CjbwM=")
	preshared, _ := base64.StdEncoding.DecodeString("FpCyhws9cxwWoV4xELtfJvjJN+zQVRPISllRWgeopVE=")
	cs := noise.NewCipherSuite(noise.DH25519, noise.CipherChaChaPoly, noise.HashBLAKE2s)
	hs, _ := noise.NewHandshakeState(noise.Config{
		CipherSuite:           cs,
		Random:                rand.Reader,
		Pattern:               noise.HandshakeIK,
		Initiator:             true,
		Prologue:              []byte("WireGuard v1 zx2c4 Jason@zx2c4.com"),
		PresharedKey:          preshared,
		PresharedKeyPlacement: 2,
		StaticKeypair:         noise.DHKey{Private: ourPrivate, Public: ourPublic},
		PeerStatic:            theirPublic,
	})
	conn, err := net.Dial("udp", "demo.wireguard.com:12913")
	if err != nil {
		log.Fatalf("error dialing udp socket: %s", err)
	}
	defer conn.Close()

	// write handshake initiation packet
	now := time.Now()
	tai64n := make([]byte, 12)
	binary.BigEndian.PutUint64(tai64n[:], 4611686018427387914+uint64(now.Unix()))
	binary.BigEndian.PutUint32(tai64n[8:], uint32(now.Nanosecond()))
	initiationPacket := make([]byte, 8)
	initiationPacket[0] = 1                                 // Type: Initiation
	initiationPacket[1] = 0                                 // Reserved
	initiationPacket[2] = 0                                 // Reserved
	initiationPacket[3] = 0                                 // Reserved
	binary.LittleEndian.PutUint32(initiationPacket[4:], 28) // Sender index: 28 (arbitrary)
	initiationPacket, _, _, _ = hs.WriteMessage(initiationPacket, tai64n)
	hasher, _ := blake2s.New256(nil)
	hasher.Write([]byte("mac1----"))
	hasher.Write(theirPublic)
	hasher, _ = blake2s.New128(hasher.Sum(nil))
	hasher.Write(initiationPacket)
	initiationPacket = append(initiationPacket, hasher.Sum(nil)[:16]...)
	initiationPacket = append(initiationPacket, make([]byte, 16)...)
	if _, err := conn.Write(initiationPacket); err != nil {
		log.Fatalf("error writing initiation packet: %s", err)
	}

	// read handshake response packet
	responsePacket := make([]byte, 92)
	n, err := conn.Read(responsePacket)
	if err != nil {
		log.Fatalf("error reading response packet: %s", err)
	}
	if n != len(responsePacket) {
		log.Fatalf("response packet too short: want %d, got %d", len(responsePacket), n)
	}
	if responsePacket[0] != 2 { // Type: Response
		log.Fatalf("response packet type wrong: want %d, got %d", 2, responsePacket[0])
	}
	if responsePacket[1] != 0 || responsePacket[2] != 0 || responsePacket[3] != 0 {
		log.Fatalf("response packet has non-zero reserved fields")
	}
	theirIndex := binary.LittleEndian.Uint32(responsePacket[4:])
	ourIndex := binary.LittleEndian.Uint32(responsePacket[8:])
	if ourIndex != 28 {
		log.Fatalf("response packet index wrong: want %d, got %d", 28, ourIndex)
	}
	payload, sendCipher, receiveCipher, err := hs.ReadMessage(nil, responsePacket[12:60])
	if err != nil {
		log.Fatalf("error reading handshake message: %s", err)
	}
	if len(payload) > 0 {
		log.Fatalf("unexpected payload: %x", payload)
	}

	// write ICMP Echo packet
	pingMessage, _ := (&icmp.Message{
		Type: ipv4.ICMPTypeEcho,
		Body: &icmp.Echo{
			ID:   921,
			Seq:  438,
			Data: []byte("WireGuard"),
		},
	}).Marshal(nil)
	pingHeader, err := (&ipv4.Header{
		Version:  ipv4.Version,
		Len:      ipv4.HeaderLen,
		TotalLen: ipv4.HeaderLen + len(pingMessage),
		Protocol: 1, // ICMP
		TTL:      20,
		Src:      net.IPv4(10, 189, 129, 2),
		Dst:      net.IPv4(10, 189, 129, 1),
	}).Marshal()
	binary.BigEndian.PutUint16(pingHeader[2:], uint16(ipv4.HeaderLen+len(pingMessage))) // fix the length endianness on BSDs
	pingData := append(append(pingHeader, pingMessage...), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)
	binary.BigEndian.PutUint16(pingData[10:], ipChecksum(pingData))
	pingPacket := make([]byte, 16)
	pingPacket[0] = 4                                          // Type: Data
	pingPacket[1] = 0                                          // Reserved
	pingPacket[2] = 0                                          // Reserved
	pingPacket[3] = 0                                          // Reserved
	binary.LittleEndian.PutUint32(pingPacket[4:], theirIndex)  // Their index
	binary.LittleEndian.PutUint64(pingPacket[8:], 0)           // Nonce
	pingPacket = sendCipher.Encrypt(pingPacket, nil, pingData) // Payload data
	if _, err := conn.Write(pingPacket); err != nil {
		log.Fatalf("error writing ping message: %s", err)
	}

	// read ICMP Echo Reply packet
	replyPacket := make([]byte, 80)
	n, err = conn.Read(replyPacket)
	if err != nil {
		log.Fatalf("error reading ping reply message: %s", err)
	}
	replyPacket = replyPacket[:n]
	if replyPacket[0] != 4 { // Type: Data
		log.Fatalf("unexpected reply packet type: %d", replyPacket[0])
	}
	if replyPacket[1] != 0 || replyPacket[2] != 0 || replyPacket[3] != 0 {
		log.Fatalf("reply packet has non-zero reserved fields")
	}
	replyPacket, err = receiveCipher.Decrypt(nil, nil, replyPacket[16:])
	if err != nil {
		log.Fatalf("error decrypting reply packet: %s", err)
	}
	replyHeaderLen := int(replyPacket[0]&0x0f) << 2
	replyLen := binary.BigEndian.Uint16(replyPacket[2:])
	replyMessage, err := icmp.ParseMessage(1, replyPacket[replyHeaderLen:replyLen])
	if err != nil {
		log.Fatalf("error parsing echo: %s", err)
	}
	echo, ok := replyMessage.Body.(*icmp.Echo)
	if !ok {
		log.Fatalf("unexpected reply body type %T", replyMessage.Body)
	}

	if echo.ID != 921 || echo.Seq != 438 || string(echo.Data) != "WireGuard" {
		log.Fatalf("incorrect echo response: %#v", echo)
	}

	keepalivePacket := make([]byte, 16)
	keepalivePacket[0] = 4                                          // Type: Data
	keepalivePacket[1] = 0                                          // Reserved
	keepalivePacket[2] = 0                                          // Reserved
	keepalivePacket[3] = 0                                          // Reserved
	binary.LittleEndian.PutUint32(keepalivePacket[4:], theirIndex)  // Their index
	binary.LittleEndian.PutUint64(keepalivePacket[8:], 1)           // Nonce
	keepalivePacket = sendCipher.Encrypt(keepalivePacket, nil, nil) // Empty data means keepalive
	if _, err := conn.Write(keepalivePacket); err != nil {
		log.Fatalf("error writing keepalive message: %s", err)
	}
}