chore: use fastrand to replace math/rand

transport/hysteria/conns/udp/hop.go

@@ -2,7 +2,6 @@ package udp
 
 import (
 	"errors"
-	"math/rand"
 	"net"
 	"strconv"
 	"strings"
@@ -12,6 +11,8 @@ import (
 
 	"github.com/Dreamacro/clash/transport/hysteria/obfs"
 	"github.com/Dreamacro/clash/transport/hysteria/utils"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 const (
@@ -85,7 +86,7 @@ func NewObfsUDPHopClientPacketConn(server string, serverPorts string, hopInterva
 		serverAddrs: serverAddrs,
 		hopInterval: hopInterval,
 		obfs:        obfs,
-		addrIndex:   rand.Intn(len(serverAddrs)),
+		addrIndex:   fastrand.Intn(len(serverAddrs)),
 		recvQueue:   make(chan *udpPacket, packetQueueSize),
 		closeChan:   make(chan struct{}),
 		bufPool: sync.Pool{
@@ -176,7 +177,7 @@ func (c *ObfsUDPHopClientPacketConn) hop(dialer utils.PacketDialer, rAddr net.Ad
 		_ = trySetPacketConnWriteBuffer(c.currentConn, c.writeBufferSize)
 	}
 	go c.recvRoutine(c.currentConn)
-	c.addrIndex = rand.Intn(len(c.serverAddrs))
+	c.addrIndex = fastrand.Intn(len(c.serverAddrs))
 }
 
 func (c *ObfsUDPHopClientPacketConn) ReadFrom(b []byte) (int, net.Addr, error) {

transport/hysteria/conns/wechat/obfs.go

@@ -2,12 +2,14 @@ package wechat
 
 import (
 	"encoding/binary"
-	"github.com/Dreamacro/clash/log"
-	"github.com/Dreamacro/clash/transport/hysteria/obfs"
-	"math/rand"
 	"net"
 	"sync"
 	"time"
+
+	"github.com/Dreamacro/clash/log"
+	"github.com/Dreamacro/clash/transport/hysteria/obfs"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 const udpBufferSize = 65535
@@ -29,7 +31,7 @@ func NewObfsWeChatUDPConn(orig net.PacketConn, obfs obfs.Obfuscator) *ObfsWeChat
 		obfs:     obfs,
 		readBuf:  make([]byte, udpBufferSize),
 		writeBuf: make([]byte, udpBufferSize),
-		sn:       rand.Uint32() & 0xFFFF,
+		sn:       fastrand.Uint32() & 0xFFFF,
 	}
 }
 

transport/hysteria/core/client.go

@@ -6,20 +6,20 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
-	"math/rand"
 	"net"
 	"strconv"
 	"sync"
 	"time"
 
-	"github.com/lunixbochs/struc"
-	"github.com/metacubex/quic-go"
-	"github.com/metacubex/quic-go/congestion"
-
 	"github.com/Dreamacro/clash/transport/hysteria/obfs"
 	"github.com/Dreamacro/clash/transport/hysteria/pmtud_fix"
 	"github.com/Dreamacro/clash/transport/hysteria/transport"
 	"github.com/Dreamacro/clash/transport/hysteria/utils"
+
+	"github.com/lunixbochs/struc"
+	"github.com/metacubex/quic-go"
+	"github.com/metacubex/quic-go/congestion"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 var (
@@ -408,7 +408,7 @@ func (c *quicPktConn) WriteTo(p []byte, addr string) error {
 	if err != nil {
 		if errSize, ok := err.(quic.ErrMessageTooLarge); ok {
 			// need to frag
-			msg.MsgID = uint16(rand.Intn(0xFFFF)) + 1 // msgID must be > 0 when fragCount > 1
+			msg.MsgID = uint16(fastrand.Intn(0xFFFF)) + 1 // msgID must be > 0 when fragCount > 1
 			fragMsgs := fragUDPMessage(msg, int(errSize))
 			for _, fragMsg := range fragMsgs {
 				msgBuf.Reset()

transport/hysteria/obfs/xplus.go

@@ -2,9 +2,8 @@ package obfs
 
 import (
 	"crypto/sha256"
-	"math/rand"
-	"sync"
-	"time"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 // [salt][obfuscated payload]
@@ -12,16 +11,12 @@ import (
 const saltLen = 16
 
 type XPlusObfuscator struct {
-	Key     []byte
-	RandSrc *rand.Rand
-
-	lk sync.Mutex
+	Key []byte
 }
 
 func NewXPlusObfuscator(key []byte) *XPlusObfuscator {
 	return &XPlusObfuscator{
-		Key:     key,
-		RandSrc: rand.New(rand.NewSource(time.Now().UnixNano())),
+		Key: key,
 	}
 }
 
@@ -40,9 +35,7 @@ func (x *XPlusObfuscator) Deobfuscate(in []byte, out []byte) int {
 }
 
 func (x *XPlusObfuscator) Obfuscate(in []byte, out []byte) int {
-	x.lk.Lock()
-	_, _ = x.RandSrc.Read(out[:saltLen]) // salt
-	x.lk.Unlock()
+	_, _ = fastrand.Read(out[:saltLen]) // salt
 	// Obfuscate the payload
 	key := sha256.Sum256(append(x.Key, out[:saltLen]...))
 	for i, c := range in {