feat: add preshared key

README.md

@@ -42,6 +42,7 @@ Peers:
       IP: "192.168.233.2"
       SubNet: 192.168.233.0/24
       PublicKey: 徯萃嵾爻燸攗窍褃冔蒔犡緇袿屿組待族砇嘀
+      PresharedKey: 瀸敀爅崾嘊嵜紼樴稍毯攣矐訷蟷扛嬋庩崛昀
       EndPoint: 1.2.3.4:56789
       AllowedIPs: ["192.168.233.2/32"]
       KeepAliveSeconds: 0
@@ -53,6 +54,7 @@ Peers:
       IP: "192.168.233.3"
       SubNet: 192.168.233.0/24
       PublicKey: 牢喨粷詸衭譛浾蘹櫠砙杹蟫瑳叩刋橋経挵蘀
+      PresharedKey: 竅琚喫従痸告烈兇厕趭萨假蔛瀇譄施烸蝫瘀
       EndPoint: ""
       AllowedIPs: ["192.168.233.3/32"]
       MTU: 752

config/cfg.go

@@ -23,6 +23,7 @@ type Peer struct {
 	IP               string   `yaml:"IP"`
 	SubNet           string   `yaml:"SubNet"`
 	PublicKey        string   `yaml:"PublicKey"`
+	PresharedKey     string   `yaml:"PresharedKey"`
 	EndPoint         string   `yaml:"EndPoint"`
 	AllowedIPs       []string `yaml:"AllowedIPs"`
 	KeepAliveSeconds int64    `yaml:"KeepAliveSeconds"`

gold/head/packet.go

@@ -6,7 +6,6 @@ import (
 	"errors"
 	"hash/crc64"
 	"net"
-	"sync/atomic"
 
 	"github.com/fumiama/WireGold/helper"
 	blake2b "github.com/fumiama/blake2b-simd"
@@ -17,7 +16,7 @@ import (
 type Packet struct {
 	// TeaTypeDataSZ len(Data)
 	// 高 4 位指定加密所用 tea key
-	// 高 4-16 位是随机值
+	// 高 4-16 位是递增值, 用于预共享密钥验证 additionalData
 	// 不得超过 65507-head 字节
 	TeaTypeDataSZ uint32
 	// Proto 详见 head
@@ -109,18 +108,16 @@ func (p *Packet) Unmarshal(data []byte) (complete bool, err error) {
 	return
 }
 
-var counter uint32
-
 // Marshal 将自身数据编码为 []byte
 // offset 必须为 8 的倍数，表示偏移的 8 位
-func (p *Packet) Marshal(src net.IP, teatype uint8, datasz uint32, offset uint16, dontfrag, hasmore bool) ([]byte, func()) {
+func (p *Packet) Marshal(src net.IP, teatype uint8, additional uint16, datasz uint32, offset uint16, dontfrag, hasmore bool) ([]byte, func()) {
 	p.TTL--
 	if p.TTL == 0 {
 		return nil, nil
 	}
 
 	if src != nil {
-		p.TeaTypeDataSZ = uint32(teatype)<<28 | (atomic.AddUint32(&counter, 1)<<16)&0x0fff0000 | datasz
+		p.TeaTypeDataSZ = uint32(teatype)<<28 | (uint32(additional&0x0fff) << 16) | datasz&0xffff
 		p.Src = src
 		offset &= 0x1fff
 		if dontfrag {
@@ -171,6 +168,11 @@ func (p *Packet) IsVaildHash() bool {
 	return sum == p.Hash
 }
 
+// AdditionalData 获得 packet 的 additionalData
+func (p *Packet) AdditionalData() uint16 {
+	return uint16((p.TeaTypeDataSZ >> 16) & 0x0fff)
+}
+
 // Put 将自己放回池中
 func (p *Packet) Put() {
 	PutPacket(p)

gold/link/crypto.go

@@ -1,5 +1,10 @@
 package link
 
+import (
+	"crypto/rand"
+	"encoding/binary"
+)
+
 // Encode 使用 TEA 加密
 func (l *Link) Encode(teatype uint8, b []byte) (eb []byte) {
 	if b == nil || teatype >= 16 {
@@ -29,3 +34,34 @@ func (l *Link) Decode(teatype uint8, b []byte) (db []byte) {
 	db = l.key[teatype].Decrypt(b)
 	return
 }
+
+// EncodePreshared 使用 chacha20poly1305 加密
+func (l *Link) EncodePreshared(additional uint16, b []byte) (eb []byte) {
+	nsz := l.aead.NonceSize()
+	// Select a random nonce, and leave capacity for the ciphertext.
+	nonce := make([]byte, nsz, nsz+len(b)+l.aead.Overhead())
+	_, err := rand.Read(nonce)
+	if err != nil {
+		return
+	}
+	// Encrypt the message and append the ciphertext to the nonce.
+	var buf [2]byte
+	binary.LittleEndian.PutUint16(buf[:], additional)
+	eb = l.aead.Seal(nonce, nonce, b, buf[:])
+	return
+}
+
+// DecodePreshared 使用 chacha20poly1305 解密
+func (l *Link) DecodePreshared(additional uint16, b []byte) (db []byte) {
+	nsz := l.aead.NonceSize()
+	if len(b) < nsz { // ciphertext too short
+		return
+	}
+	// Split nonce and ciphertext.
+	nonce, ciphertext := b[:nsz], b[nsz:]
+	// Decrypt the message and check it wasn't tampered with.
+	var buf [2]byte
+	binary.LittleEndian.PutUint16(buf[:], additional)
+	db, _ = l.aead.Open(nil, nonce, ciphertext, buf[:])
+	return
+}

gold/link/link.go

@@ -1,6 +1,7 @@
 package link
 
 import (
+	"crypto/cipher"
 	"errors"
 	"net"
 
@@ -14,6 +15,8 @@ import (
 type Link struct {
 	// peer 的公钥
 	pubk *[32]byte
+	// 发包计数, 分片算一个
+	sendcount uintptr
 	// 收到的包的队列
 	// 没有下层 nic 时
 	// 包会分发到此
@@ -26,6 +29,8 @@ type Link struct {
 	allowedips []*net.IPNet
 	// 连接所用对称加密密钥
 	key []tea.TEA
+	// 连接所用预共享密钥
+	aead cipher.AEAD
 	// 本机信息
 	me *Me
 	// 连接的状态，详见下方 const

gold/link/listen.go

@@ -43,40 +43,48 @@ func (m *Me) listenthread(conn *net.UDPConn, mu *sync.Mutex) {
 		sz := packet.TeaTypeDataSZ & 0x0000ffff
 		r := int(sz) - len(packet.Data)
 		if r > 0 {
-			logrus.Warnln("[link] packet from endpoint", addr, "is smaller than it declared: drop it")
+			logrus.Warnln("[listen] packet from endpoint", addr, "is smaller than it declared: drop it")
 			packet.Put()
 			continue
 		}
 		p, ok := m.IsInPeer(packet.Src.String())
-		logrus.Debugln("[link] recv from endpoint", addr, "src", packet.Src, "dst", packet.Dst)
+		logrus.Debugln("[listen] recv from endpoint", addr, "src", packet.Src, "dst", packet.Dst)
-		// logrus.Debugln("[link] recv:", hex.EncodeToString(lbf))
+		// logrus.Debugln("[listen] recv:", hex.EncodeToString(lbf))
 		if !ok {
-			logrus.Warnln("[link] packet from", packet.Src, "to", packet.Dst, "is refused")
+			logrus.Warnln("[listen] packet from", packet.Src, "to", packet.Dst, "is refused")
 			packet.Put()
 			continue
 		}
 		if p.endpoint == nil || p.endpoint.String() != addr.String() {
-			logrus.Infoln("[link] set endpoint of peer", p.peerip, "to", addr.String())
+			logrus.Infoln("[listen] set endpoint of peer", p.peerip, "to", addr.String())
 			p.endpoint = addr
 		}
 		switch {
 		case p.IsToMe(packet.Dst):
 			packet.Data = p.Decode(uint8(packet.TeaTypeDataSZ>>28), packet.Data)
 			if !packet.IsVaildHash() {
-				logrus.Debugln("[link] drop invalid packet")
+				logrus.Debugln("[listen] drop invalid hash packet")
 				packet.Put()
 				continue
 			}
+			if p.aead != nil {
+				packet.Data = p.DecodePreshared(packet.AdditionalData(), packet.Data)
+				if packet.Data == nil {
+					logrus.Debugln("[listen] drop invalid additional data packet")
+					packet.Put()
+					continue
+				}
+			}
 			switch packet.Proto {
 			case head.ProtoHello:
 				switch p.status {
 				case LINK_STATUS_DOWN:
 					n, err = p.WriteAndPut(head.NewPacket(head.ProtoHello, m.SrcPort(), p.peerip, m.DstPort(), nil), false)
 					if err == nil {
-						logrus.Debugln("[link] send", n, "bytes hello ack packet")
+						logrus.Debugln("[listen] send", n, "bytes hello ack packet")
 						p.status = LINK_STATUS_HALFUP
 					} else {
-						logrus.Errorln("[link] send hello ack packet error:", err)
+						logrus.Errorln("[listen] send hello ack packet error:", err)
 					}
 				case LINK_STATUS_HALFUP:
 					p.status = LINK_STATUS_UP
@@ -84,47 +92,47 @@ func (m *Me) listenthread(conn *net.UDPConn, mu *sync.Mutex) {
 				}
 				packet.Put()
 			case head.ProtoNotify:
-				logrus.Infoln("[link] recv notify from", packet.Src)
+				logrus.Infoln("[listen] recv notify from", packet.Src)
 				go p.onNotify(packet.Data)
 				packet.Put()
 			case head.ProtoQuery:
-				logrus.Infoln("[link] recv query from", packet.Src)
+				logrus.Infoln("[listen] recv query from", packet.Src)
 				go p.onQuery(packet.Data)
 				packet.Put()
 			case head.ProtoData:
 				if p.pipe != nil {
 					p.pipe <- packet
-					logrus.Debugln("[link] deliver to pipe of", p.peerip)
+					logrus.Debugln("[listen] deliver to pipe of", p.peerip)
 				} else {
 					m.nic.Write(packet.Data)
-					logrus.Debugln("[link] deliver", len(packet.Data), "bytes data to nic")
+					logrus.Debugln("[listen] deliver", len(packet.Data), "bytes data to nic")
 					packet.Put()
 				}
 			default:
-				logrus.Warnln("[link] recv unknown proto:", packet.Proto)
+				logrus.Warnln("[listen] recv unknown proto:", packet.Proto)
 				packet.Put()
 			}
 		case p.Accept(packet.Dst):
 			if !p.allowtrans {
-				logrus.Warnln("[link] refused to trans packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)))
+				logrus.Warnln("[listen] refused to trans packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)))
 				packet.Put()
 				continue
 			}
 			// 转发
 			lnk := m.router.NextHop(packet.Dst.String())
 			if lnk == nil {
-				logrus.Warnln("[link] transfer drop packet: nil nexthop")
+				logrus.Warnln("[listen] transfer drop packet: nil nexthop")
 				packet.Put()
 				continue
 			}
 			n, err = lnk.WriteAndPut(packet, true)
 			if err == nil {
-				logrus.Debugln("[link] trans", n, "bytes packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)))
+				logrus.Debugln("[listen] trans", n, "bytes packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)))
 			} else {
-				logrus.Errorln("[link] trans packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)), "err:", err)
+				logrus.Errorln("[listen] trans packet to", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)), "err:", err)
 			}
 		default:
-			logrus.Warnln("[link] packet dst", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)), "is not in peers")
+			logrus.Warnln("[listen] packet dst", packet.Dst.String()+":"+strconv.Itoa(int(packet.DstPort)), "is not in peers")
 			packet.Put()
 		}
 	}

gold/link/nat.go

@@ -16,14 +16,14 @@ import (
 // 以秒为单位，小于等于 0 不发送
 func (l *Link) keepAlive(dur int64) {
 	if dur > 0 {
-		logrus.Infoln("[link.nat] start to keep alive")
+		logrus.Infoln("[nat] start to keep alive")
 		t := time.NewTicker(time.Second * time.Duration(dur))
 		for range t.C {
 			n, err := l.WriteAndPut(head.NewPacket(head.ProtoHello, l.me.srcport, l.peerip, l.me.dstport, nil), false)
 			if err == nil {
-				logrus.Infoln("[link] send", n, "bytes keep alive packet")
+				logrus.Infoln("[nat] send", n, "bytes keep alive packet")
 			} else {
-				logrus.Errorln("[link] send keep alive packet error:", err)
+				logrus.Errorln("[nat] send keep alive packet error:", err)
 			}
 		}
 	}
@@ -37,7 +37,7 @@ func (l *Link) onNotify(packet []byte) {
 	notify := make(head.Notify, 32)
 	err := json.Unmarshal(packet, &notify)
 	if err != nil {
-		logrus.Errorln("[notify] json unmarshal err:", err)
+		logrus.Errorln("[nat] notify json unmarshal err:", err)
 		return
 	}
 	// 2. endpoint注册
@@ -50,12 +50,12 @@ func (l *Link) onNotify(packet []byte) {
 			if ok {
 				if p.endpoint.String() != ep {
 					p.endpoint = addr
-					logrus.Infoln("[notify] set ep of peer", peer, "to", ep)
+					logrus.Infoln("[nat] notify set ep of peer", peer, "to", ep)
 				}
 				continue
 			}
 		}
-		logrus.Debugln("[notify] drop invalid peer:", peer, "ep:", ep)
+		logrus.Debugln("[nat] notify drop invalid peer:", peer, "ep:", ep)
 	}
 }
 
@@ -69,7 +69,7 @@ func (l *Link) onQuery(packet []byte) {
 	var peers head.Query
 	err := json.Unmarshal(packet, &peers)
 	if err != nil {
-		logrus.Errorln("[qurey] json unmarshal err:", err)
+		logrus.Errorln("[nat] query json unmarshal err:", err)
 		return
 	}
 
@@ -84,7 +84,7 @@ func (l *Link) onQuery(packet []byte) {
 		}
 	}
 	if len(notify) > 0 {
-		logrus.Infoln("[query] wrap", len(notify), "notify")
+		logrus.Infoln("[nat] query wrap", len(notify), "notify")
 		w := helper.SelectWriter()
 		json.NewEncoder(w).Encode(&notify)
 		l.WriteAndPut(head.NewPacket(head.ProtoNotify, l.me.srcport, l.peerip, l.me.dstport, w.Bytes()), false)
@@ -103,10 +103,10 @@ func (l *Link) sendquery(tick time.Duration, peers ...string) {
 	}
 	t := time.NewTicker(tick)
 	for range t.C {
-		logrus.Infoln("[query] send query to", l.peerip)
+		logrus.Infoln("[nat] query send query to", l.peerip)
 		_, err = l.WriteAndPut(head.NewPacket(head.ProtoQuery, l.me.srcport, l.peerip, l.me.dstport, data), false)
 		if err != nil {
-			logrus.Errorln("[query] write err:", err)
+			logrus.Errorln("[nat] query write err:", err)
 		}
 	}
 }

gold/link/peer.go

@@ -8,6 +8,7 @@ import (
 	curve "github.com/fumiama/go-x25519"
 	tea "github.com/fumiama/gofastTEA"
 	"github.com/sirupsen/logrus"
+	"golang.org/x/crypto/chacha20poly1305"
 )
 
 type PeerConfig struct {
@@ -15,6 +16,7 @@ type PeerConfig struct {
 	EndPoint                string
 	AllowedIPs, Querys      []string
 	PubicKey                *[32]byte
+	PresharedKey            *[32]byte
 	KeepAliveDur, QueryTick int64
 	MTU                     uint16
 	AllowTrans, NoPipe      bool
@@ -52,6 +54,13 @@ func (m *Me) AddPeer(cfg *PeerConfig) (l *Link) {
 			}
 		}
 	}
+	if cfg.PresharedKey != nil {
+		var err error
+		l.aead, err = chacha20poly1305.NewX(cfg.PresharedKey[:])
+		if err != nil {
+			panic(err)
+		}
+	}
 	if cfg.EndPoint != "" {
 		e, err := net.ResolveUDPAddr("udp", cfg.EndPoint)
 		if err != nil {

gold/link/send.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"math/rand"
+	"sync/atomic"
 
 	"github.com/fumiama/WireGold/gold/head"
 	"github.com/sirupsen/logrus"
@@ -12,16 +13,23 @@ import (
 // WriteAndPut 向 peer 发包并将包放回缓存池
 func (l *Link) WriteAndPut(p *head.Packet, istransfer bool) (n int, err error) {
 	teatype := uint8(rand.Intn(16))
+	sndcnt := atomic.AddUintptr(&l.sendcount, 1)
 	if len(p.Data) <= int(l.mtu) {
 		if !istransfer {
 			p.FillHash()
+			if l.aead != nil {
+				p.Data = l.EncodePreshared(uint16(sndcnt), p.Data)
+			}
 			p.Data = l.Encode(teatype, p.Data)
 		}
 		defer p.Put()
-		return l.write(p, teatype, uint32(len(p.Data)), 0, istransfer, false)
+		return l.write(p, teatype, uint16(sndcnt), uint32(len(p.Data)), 0, istransfer, false)
 	}
 	if !istransfer {
 		p.FillHash()
+		if l.aead != nil {
+			p.Data = l.EncodePreshared(uint16(sndcnt), p.Data)
+		}
 		p.Data = l.Encode(teatype, p.Data)
 	}
 	data := p.Data
@@ -31,9 +39,9 @@ func (l *Link) WriteAndPut(p *head.Packet, istransfer bool) (n int, err error) {
 	packet := head.SelectPacket()
 	*packet = *p
 	for ; int(totl)-i > int(l.mtu); i += int(l.mtu) {
-		logrus.Debugln("[link] split frag", i, ":", i+int(l.mtu), ", remain:", int(totl)-i-int(l.mtu))
+		logrus.Debugln("[send] split frag", i, ":", i+int(l.mtu), ", remain:", int(totl)-i-int(l.mtu))
 		packet.Data = data[:int(l.mtu)]
-		cnt, err := l.write(packet, teatype, totl, uint16(i>>3), istransfer, true)
+		cnt, err := l.write(packet, teatype, uint16(sndcnt), totl, uint16(i>>3), istransfer, true)
 		n += cnt
 		if err != nil {
 			return n, err
@@ -43,33 +51,33 @@ func (l *Link) WriteAndPut(p *head.Packet, istransfer bool) (n int, err error) {
 	}
 	packet.Put()
 	p.Data = data
-	cnt, err := l.write(p, teatype, totl, uint16(i>>3), istransfer, false)
+	cnt, err := l.write(p, teatype, uint16(sndcnt), totl, uint16(i>>3), istransfer, false)
 	p.Put()
 	n += cnt
 	return n, err
 }
 
 // write 向 peer 发一个包
-func (l *Link) write(p *head.Packet, teatype uint8, datasz uint32, offset uint16, istransfer, hasmore bool) (n int, err error) {
+func (l *Link) write(p *head.Packet, teatype uint8, additional uint16, datasz uint32, offset uint16, istransfer, hasmore bool) (n int, err error) {
 	var d []byte
 	var cl func()
 	if istransfer {
 		if p.Flags&0x4000 == 0x4000 && len(p.Data) > int(l.mtu) {
 			return len(p.Data), errors.New("drop dont fragmnet big trans packet")
 		}
-		d, cl = p.Marshal(nil, teatype, 0, 0, false, false)
+		d, cl = p.Marshal(nil, teatype, additional, 0, 0, false, false)
 	} else {
-		d, cl = p.Marshal(l.me.me, teatype, datasz, offset, false, hasmore)
+		d, cl = p.Marshal(l.me.me, teatype, additional, datasz, offset, false, hasmore)
 	}
 	if d == nil {
-		return 0, errors.New("[link] ttl exceeded")
+		return 0, errors.New("[send] ttl exceeded")
 	}
 	if err == nil {
 		peerep := l.endpoint
 		if peerep == nil {
-			return 0, errors.New("[link] nil endpoint of " + p.Dst.String())
+			return 0, errors.New("[send] nil endpoint of " + p.Dst.String())
 		}
-		logrus.Debugln("[link] write", len(d), "bytes data from ep", l.me.myep.LocalAddr(), "to", peerep, "offset:", fmt.Sprintf("%04x", offset))
+		logrus.Debugln("[send] write", len(d), "bytes data from ep", l.me.myep.LocalAddr(), "to", peerep, "offset:", fmt.Sprintf("%04x", offset))
 		n, err = l.me.myep.WriteToUDP(d, peerep)
 		cl()
 	}

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"crypto/rand"
 	"flag"
 	"fmt"
 	"os"
@@ -19,6 +20,7 @@ import (
 func main() {
 	help := flag.Bool("h", false, "display this help")
 	gen := flag.Bool("g", false, "generate key pair")
+	pshgen := flag.Bool("pg", false, "generate preshared key")
 	showp := flag.Bool("p", false, "show my publickey")
 	file := flag.String("c", "config.yaml", "specify conf file")
 	debug := flag.Bool("d", false, "print debug logs")
@@ -50,6 +52,19 @@ func main() {
 		fmt.Println("PrivateKey:", helper.BytesToString(prvk[:57]))
 		os.Exit(0)
 	}
+	if *pshgen {
+		var buf [32]byte
+		_, err := rand.Read(buf[:])
+		if err != nil {
+			panic(err)
+		}
+		pshk, err := base14.UTF16BE2UTF8(base14.Encode(buf[:]))
+		if err != nil {
+			panic(err)
+		}
+		fmt.Println("PresharedKey:", helper.BytesToString(pshk[:57]))
+		os.Exit(0)
+	}
 	if *logfile != "-" {
 		f, err := os.Create(*logfile)
 		if err != nil {

upper/services/wg/wg.go

@@ -107,7 +107,19 @@ func (wg *WG) init(srcport, dstport uint16) {
 		}
 		n := copy(peerkey[:], base14.Decode(k))
 		if n != 32 {
-			panic("peer public key length is not 32")
+			panic("peer public key length < 32")
+		}
+		var pshk *[32]byte
+		if peer.PresharedKey != "" {
+			k, err := base14.UTF82UTF16BE(helper.StringToBytes(peer.PresharedKey + suffix32))
+			if err != nil {
+				panic(err)
+			}
+			pshk = &[32]byte{}
+			n := copy(pshk[:], base14.Decode(k))
+			if n != 32 {
+				panic("peer preshared key length < 32")
+			}
 		}
 		wg.me.AddPeer(&link.PeerConfig{
 			PeerIP:       peer.IP,
@@ -115,6 +127,7 @@ func (wg *WG) init(srcport, dstport uint16) {
 			AllowedIPs:   peer.AllowedIPs,
 			Querys:       peer.QueryList,
 			PubicKey:     &peerkey,
+			PresharedKey: pshk,
 			KeepAliveDur: peer.KeepAliveSeconds,
 			QueryTick:    peer.QuerySeconds,
 			MTU:          uint16(peer.MTU),