chore: use fastrand to replace math/rand

common/convert/util.go

@@ -2,7 +2,6 @@ package convert
 
 import (
 	"encoding/base64"
-	"math/rand"
 	"net/http"
 	"strings"
 	"time"
@@ -10,6 +9,7 @@ import (
 	"github.com/Dreamacro/clash/common/utils"
 
 	"github.com/metacubex/sing-shadowsocks/shadowimpl"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 var hostsSuffix = []string{
@@ -303,11 +303,11 @@ func RandHost() string {
 	prefix += string(buf[6:8]) + "-"
 	prefix += string(buf[len(buf)-8:])
 
-	return prefix + hostsSuffix[rand.Intn(hostsLen)]
+	return prefix + hostsSuffix[fastrand.Intn(hostsLen)]
 }
 
 func RandUserAgent() string {
-	return userAgents[rand.Intn(uaLen)]
+	return userAgents[fastrand.Intn(uaLen)]
 }
 
 func SetUserAgent(header http.Header) {

common/pool/alloc_test.go

@@ -1,10 +1,10 @@
 package pool
 
 import (
-	"math/rand"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 func TestAllocGet(t *testing.T) {
@@ -43,6 +43,6 @@ func TestAllocPutThenGet(t *testing.T) {
 
 func BenchmarkMSB(b *testing.B) {
 	for i := 0; i < b.N; i++ {
-		msb(rand.Int())
+		msb(fastrand.Int())
 	}
 }

component/resolver/resolver.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"math/rand"
 	"net"
 	"net/netip"
 	"strings"
@@ -13,6 +12,7 @@ import (
 	"github.com/Dreamacro/clash/component/trie"
 
 	"github.com/miekg/dns"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 var (
@@ -96,7 +96,7 @@ func ResolveIPv4WithResolver(ctx context.Context, host string, r Resolver) (neti
 	} else if len(ips) == 0 {
 		return netip.Addr{}, fmt.Errorf("%w: %s", ErrIPNotFound, host)
 	}
-	return ips[rand.Intn(len(ips))], nil
+	return ips[fastrand.Intn(len(ips))], nil
 }
 
 // ResolveIPv4 with a host, return ipv4
@@ -153,7 +153,7 @@ func ResolveIPv6WithResolver(ctx context.Context, host string, r Resolver) (neti
 	} else if len(ips) == 0 {
 		return netip.Addr{}, fmt.Errorf("%w: %s", ErrIPNotFound, host)
 	}
-	return ips[rand.Intn(len(ips))], nil
+	return ips[fastrand.Intn(len(ips))], nil
 }
 
 func ResolveIPv6(ctx context.Context, host string) (netip.Addr, error) {
@@ -202,7 +202,7 @@ func ResolveIPWithResolver(ctx context.Context, host string, r Resolver) (netip.
 	} else if len(ips) == 0 {
 		return netip.Addr{}, fmt.Errorf("%w: %s", ErrIPNotFound, host)
 	}
-	return ips[rand.Intn(len(ips))], nil
+	return ips[fastrand.Intn(len(ips))], nil
 }
 
 // ResolveIP with a host, return ip

dns/client.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"crypto/tls"
 	"fmt"
-	"math/rand"
 	"net"
 	"net/netip"
 	"strings"
@@ -16,6 +15,7 @@ import (
 	"github.com/Dreamacro/clash/component/resolver"
 
 	D "github.com/miekg/dns"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 type client struct {
@@ -68,7 +68,7 @@ func (c *client) ExchangeContext(ctx context.Context, m *D.Msg) (*D.Msg, error)
 		} else if len(ips) == 0 {
 			return nil, fmt.Errorf("%w: %s", resolver.ErrIPNotFound, c.host)
 		}
-		ip = ips[rand.Intn(len(ips))]
+		ip = ips[fastrand.Intn(len(ips))]
 	}
 
 	network := "udp"

dns/resolver.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"math/rand"
 	"net/netip"
 	"strings"
 	"time"
@@ -20,6 +19,7 @@ import (
 	"github.com/Dreamacro/clash/log"
 
 	D "github.com/miekg/dns"
+	"github.com/zhangyunhao116/fastrand"
 	"golang.org/x/sync/singleflight"
 )
 
@@ -113,7 +113,7 @@ func (r *Resolver) ResolveIP(ctx context.Context, host string) (ip netip.Addr, e
 	} else if len(ips) == 0 {
 		return netip.Addr{}, fmt.Errorf("%w: %s", resolver.ErrIPNotFound, host)
 	}
-	return ips[rand.Intn(len(ips))], nil
+	return ips[fastrand.Intn(len(ips))], nil
 }
 
 // LookupIPv4 request with TypeA
@@ -129,7 +129,7 @@ func (r *Resolver) ResolveIPv4(ctx context.Context, host string) (ip netip.Addr,
 	} else if len(ips) == 0 {
 		return netip.Addr{}, fmt.Errorf("%w: %s", resolver.ErrIPNotFound, host)
 	}
-	return ips[rand.Intn(len(ips))], nil
+	return ips[fastrand.Intn(len(ips))], nil
 }
 
 // LookupIPv6 request with TypeAAAA
@@ -145,7 +145,7 @@ func (r *Resolver) ResolveIPv6(ctx context.Context, host string) (ip netip.Addr,
 	} else if len(ips) == 0 {
 		return netip.Addr{}, fmt.Errorf("%w: %s", resolver.ErrIPNotFound, host)
 	}
-	return ips[rand.Intn(len(ips))], nil
+	return ips[fastrand.Intn(len(ips))], nil
 }
 
 func (r *Resolver) shouldIPFallback(ip netip.Addr) bool {

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"
+	"github.com/zhangyunhao116/fastrand"
-	"time"
 )
 
 // [salt][obfuscated payload]
@@ -13,15 +12,11 @@ const saltLen = 16
 
 type XPlusObfuscator struct {
 	Key []byte
-	RandSrc *rand.Rand
-
-	lk sync.Mutex
 }
 
 func NewXPlusObfuscator(key []byte) *XPlusObfuscator {
 	return &XPlusObfuscator{
 		Key: key,
-		RandSrc: rand.New(rand.NewSource(time.Now().UnixNano())),
 	}
 }
 
@@ -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()
+	_, _ = fastrand.Read(out[:saltLen]) // salt
-	_, _ = x.RandSrc.Read(out[:saltLen]) // salt
-	x.lk.Unlock()
 	// Obfuscate the payload
 	key := sha256.Sum256(append(x.Key, out[:saltLen]...))
 	for i, c := range in {

transport/simple-obfs/http.go

@@ -5,11 +5,12 @@ import (
 	"encoding/base64"
 	"fmt"
 	"io"
-	"math/rand"
 	"net"
 	"net/http"
 
 	"github.com/Dreamacro/clash/common/pool"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 // HTTPObfs is shadowsocks http simple-obfs implementation
@@ -63,9 +64,9 @@ func (ho *HTTPObfs) Read(b []byte) (int, error) {
 func (ho *HTTPObfs) Write(b []byte) (int, error) {
 	if ho.firstRequest {
 		randBytes := make([]byte, 16)
-		rand.Read(randBytes)
+		fastrand.Read(randBytes)
 		req, _ := http.NewRequest("GET", fmt.Sprintf("http://%s/", ho.host), bytes.NewBuffer(b[:]))
-		req.Header.Set("User-Agent", fmt.Sprintf("curl/7.%d.%d", rand.Int()%54, rand.Int()%2))
+		req.Header.Set("User-Agent", fmt.Sprintf("curl/7.%d.%d", fastrand.Int()%54, fastrand.Int()%2))
 		req.Header.Set("Upgrade", "websocket")
 		req.Header.Set("Connection", "Upgrade")
 		req.Host = ho.host

transport/simple-obfs/tls.go

@@ -4,16 +4,13 @@ import (
 	"bytes"
 	"encoding/binary"
 	"io"
-	"math/rand"
 	"net"
 	"time"
 
 	"github.com/Dreamacro/clash/common/pool"
-)
 
-func init() {
+	"github.com/zhangyunhao116/fastrand"
-	rand.Seed(time.Now().Unix())
+)
-}
 
 const (
 	chunkSize = 1 << 14 // 2 ** 14 == 16 * 1024
@@ -130,8 +127,8 @@ func NewTLSObfs(conn net.Conn, server string) net.Conn {
 func makeClientHelloMsg(data []byte, server string) []byte {
 	random := make([]byte, 28)
 	sessionID := make([]byte, 32)
-	rand.Read(random)
+	fastrand.Read(random)
-	rand.Read(sessionID)
+	fastrand.Read(sessionID)
 
 	buf := &bytes.Buffer{}
 

transport/ssr/obfs/http_simple.go

@@ -4,12 +4,13 @@ import (
 	"bytes"
 	"encoding/hex"
 	"io"
-	"math/rand"
 	"net"
 	"strconv"
 	"strings"
 
 	"github.com/Dreamacro/clash/common/pool"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 func init() {
@@ -81,7 +82,7 @@ func (c *httpConn) Write(b []byte) (int, error) {
 	bLength := len(b)
 	headDataLength := bLength
 	if bLength-headLength > 64 {
-		headDataLength = headLength + rand.Intn(65)
+		headDataLength = headLength + fastrand.Intn(65)
 	}
 	headData := b[:headDataLength]
 	b = b[headDataLength:]
@@ -99,7 +100,7 @@ func (c *httpConn) Write(b []byte) (int, error) {
 		}
 	}
 	hosts := strings.Split(host, ",")
-	host = hosts[rand.Intn(len(hosts))]
+	host = hosts[fastrand.Intn(len(hosts))]
 
 	buf := pool.GetBuffer()
 	defer pool.PutBuffer(buf)
@@ -118,7 +119,7 @@ func (c *httpConn) Write(b []byte) (int, error) {
 		buf.WriteString(body + "\r\n\r\n")
 	} else {
 		buf.WriteString("User-Agent: ")
-		buf.WriteString(userAgent[rand.Intn(len(userAgent))])
+		buf.WriteString(userAgent[fastrand.Intn(len(userAgent))])
 		buf.WriteString("\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\r\nAccept-Language: en-US,en;q=0.8\r\nAccept-Encoding: gzip, deflate\r\n")
 		if c.post {
 			packBoundary(buf)
@@ -146,7 +147,7 @@ func packBoundary(buf *bytes.Buffer) {
 	buf.WriteString("Content-Type: multipart/form-data; boundary=")
 	set := "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
 	for i := 0; i < 32; i++ {
-		buf.WriteByte(set[rand.Intn(62)])
+		buf.WriteByte(set[fastrand.Intn(62)])
 	}
 	buf.WriteString("\r\n")
 }

transport/ssr/obfs/random_head.go

@@ -3,10 +3,11 @@ package obfs
 import (
 	"encoding/binary"
 	"hash/crc32"
-	"math/rand"
 	"net"
 
 	"github.com/Dreamacro/clash/common/pool"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 func init() {
@@ -53,10 +54,10 @@ func (c *randomHeadConn) Write(b []byte) (int, error) {
 	c.buf = append(c.buf, b...)
 	if !c.hasSentHeader {
 		c.hasSentHeader = true
-		dataLength := rand.Intn(96) + 4
+		dataLength := fastrand.Intn(96) + 4
 		buf := pool.Get(dataLength + 4)
 		defer pool.Put(buf)
-		rand.Read(buf[:dataLength])
+		fastrand.Read(buf[:dataLength])
 		binary.LittleEndian.PutUint32(buf[dataLength:], 0xffffffff-crc32.ChecksumIEEE(buf[:dataLength]))
 		_, err := c.Conn.Write(buf)
 		return len(b), err

transport/ssr/obfs/tls1.2_ticket_auth.go

@@ -4,13 +4,14 @@ import (
 	"bytes"
 	"crypto/hmac"
 	"encoding/binary"
-	"math/rand"
 	"net"
 	"strings"
 	"time"
 
 	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/transport/ssr/tools"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 func init() {
@@ -25,7 +26,7 @@ type tls12Ticket struct {
 
 func newTLS12Ticket(b *Base) Obfs {
 	r := &tls12Ticket{Base: b, authData: &authData{}}
-	rand.Read(r.clientID[:])
+	fastrand.Read(r.clientID[:])
 	return r
 }
 
@@ -90,7 +91,7 @@ func (c *tls12TicketConn) Write(b []byte) (int, error) {
 		buf := pool.GetBuffer()
 		defer pool.PutBuffer(buf)
 		for len(b) > 2048 {
-			size := rand.Intn(4096) + 100
+			size := fastrand.Intn(4096) + 100
 			if len(b) < size {
 				size = len(b)
 			}
@@ -196,7 +197,7 @@ func packSNIData(buf *bytes.Buffer, u string) {
 }
 
 func (c *tls12TicketConn) packTicketBuf(buf *bytes.Buffer, u string) {
-	length := 16 * (rand.Intn(17) + 8)
+	length := 16 * (fastrand.Intn(17) + 8)
 	buf.Write([]byte{0, 0x23})
 	binary.Write(buf, binary.BigEndian, uint16(length))
 	tools.AppendRandBytes(buf, length)
@@ -221,6 +222,6 @@ func (t *tls12Ticket) getHost() string {
 		host = ""
 	}
 	hosts := strings.Split(host, ",")
-	host = hosts[rand.Intn(len(hosts))]
+	host = hosts[fastrand.Intn(len(hosts))]
 	return host
 }

transport/ssr/protocol/auth_aes128_sha1.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"encoding/binary"
 	"math"
-	"math/rand"
 	"net"
 	"strconv"
 	"strings"
@@ -12,6 +11,8 @@ import (
 	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/log"
 	"github.com/Dreamacro/clash/transport/ssr/tools"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 type (
@@ -64,7 +65,7 @@ func (a *authAES128) initUserData() {
 	}
 	if len(a.userKey) == 0 {
 		a.userKey = a.Key
-		rand.Read(a.userID[:])
+		fastrand.Read(a.userID[:])
 	}
 }
 
@@ -198,7 +199,7 @@ func (a *authAES128) packData(poolBuf *bytes.Buffer, data []byte, fullDataLength
 }
 
 func trapezoidRandom(max int, d float64) int {
-	base := rand.Float64()
+	base := fastrand.Float64()
 	if d-0 > 1e-6 {
 		a := 1 - d
 		base = (math.Sqrt(a*a+4*d*base) - a) / (2 * d)
@@ -219,10 +220,10 @@ func (a *authAES128) getRandDataLengthForPackData(dataLength, fullDataLength int
 		if revLength > -1460 {
 			return trapezoidRandom(revLength+1460, -0.3)
 		}
-		return rand.Intn(32)
+		return fastrand.Intn(32)
 	}
 	if dataLength > 900 {
-		return rand.Intn(revLength)
+		return fastrand.Intn(revLength)
 	}
 	return trapezoidRandom(revLength, -0.3)
 }
@@ -247,7 +248,7 @@ func (a *authAES128) packAuthData(poolBuf *bytes.Buffer, data []byte) {
 	copy(macKey, a.iv)
 	copy(macKey[len(a.iv):], a.Key)
 
-	poolBuf.WriteByte(byte(rand.Intn(256)))
+	poolBuf.WriteByte(byte(fastrand.Intn(256)))
 	poolBuf.Write(a.hmac(macKey, poolBuf.Bytes())[:6])
 	poolBuf.Write(a.userID[:])
 	err := a.authData.putEncryptedData(poolBuf, a.userKey, [2]int{packedAuthDataLength, randDataLength}, a.salt)
@@ -263,9 +264,9 @@ func (a *authAES128) packAuthData(poolBuf *bytes.Buffer, data []byte) {
 
 func (a *authAES128) getRandDataLengthForPackAuthData(size int) int {
 	if size > 400 {
-		return rand.Intn(512)
+		return fastrand.Intn(512)
 	}
-	return rand.Intn(1024)
+	return fastrand.Intn(1024)
 }
 
 func (a *authAES128) packRandData(poolBuf *bytes.Buffer, size int) {

transport/ssr/protocol/auth_sha1_v4.go

@@ -5,11 +5,12 @@ import (
 	"encoding/binary"
 	"hash/adler32"
 	"hash/crc32"
-	"math/rand"
 	"net"
 
 	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/transport/ssr/tools"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 func init() {
@@ -176,7 +177,7 @@ func (a *authSHA1V4) getRandDataLength(size int) int {
 		return 0
 	}
 	if size > 400 {
-		return rand.Intn(256)
+		return fastrand.Intn(256)
 	}
-	return rand.Intn(512)
+	return fastrand.Intn(512)
 }

transport/ssr/protocol/base.go

@@ -6,13 +6,14 @@ import (
 	"crypto/cipher"
 	"encoding/base64"
 	"encoding/binary"
-	"math/rand"
 	"sync"
 	"time"
 
 	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/log"
 	"github.com/Dreamacro/clash/transport/shadowsocks/core"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 type Base struct {
@@ -37,8 +38,8 @@ func (a *authData) next() *authData {
 	a.mutex.Lock()
 	defer a.mutex.Unlock()
 	if a.connectionID > 0xff000000 || a.connectionID == 0 {
-		rand.Read(a.clientID[:])
+		fastrand.Read(a.clientID[:])
-		a.connectionID = rand.Uint32() & 0xffffff
+		a.connectionID = fastrand.Uint32() & 0xffffff
 	}
 	a.connectionID++
 	copy(r.clientID[:], a.clientID[:])

transport/ssr/protocol/protocol.go

@@ -4,8 +4,9 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
-	"math/rand"
 	"net"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 var (
@@ -68,7 +69,7 @@ func getHeadSize(b []byte, defaultValue int) int {
 
 func getDataLength(b []byte) int {
 	bLength := len(b)
-	dataLength := getHeadSize(b, 30) + rand.Intn(32)
+	dataLength := getHeadSize(b, 30) + fastrand.Intn(32)
 	if bLength < dataLength {
 		return bLength
 	}

transport/tuic/client.go

@@ -6,19 +6,19 @@ import (
 	"context"
 	"crypto/tls"
 	"errors"
-	"math/rand"
 	"net"
 	"runtime"
 	"sync"
 	"sync/atomic"
 	"time"
 
-	"github.com/metacubex/quic-go"
-
 	N "github.com/Dreamacro/clash/common/net"
 	"github.com/Dreamacro/clash/common/pool"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/log"
+
+	"github.com/metacubex/quic-go"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 var (
@@ -352,7 +352,7 @@ func (t *clientImpl) ListenPacketWithDialer(ctx context.Context, metadata *C.Met
 	pipe1, pipe2 := net.Pipe()
 	var connId uint32
 	for {
-		connId = rand.Uint32()
+		connId = fastrand.Uint32()
 		_, loaded := t.udpInputMap.LoadOrStore(connId, pipe1)
 		if !loaded {
 			break

transport/tuic/congestion/bbr_sender.go

@@ -5,11 +5,11 @@ package congestion
 import (
 	"fmt"
 	"math"
-	"math/rand"
 	"net"
 	"time"
 
 	"github.com/metacubex/quic-go/congestion"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 const (
@@ -780,7 +780,7 @@ func (b *bbrSender) EnterProbeBandwidthMode(now time.Time) {
 	// Pick a random offset for the gain cycle out of {0, 2..7} range. 1 is
 	// excluded because in that case increased gain and decreased gain would not
 	// follow each other.
-	b.cycleCurrentOffset = rand.Int() % (GainCycleLength - 1)
+	b.cycleCurrentOffset = fastrand.Int() % (GainCycleLength - 1)
 	if b.cycleCurrentOffset >= 1 {
 		b.cycleCurrentOffset += 1
 	}

transport/vless/vision.go

@@ -3,12 +3,11 @@ package vless
 import (
 	"bytes"
 	"encoding/binary"
-	"math/rand"
-
 	"github.com/Dreamacro/clash/common/buf"
 	"github.com/Dreamacro/clash/log"
 
 	"github.com/gofrs/uuid"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 const (
@@ -24,9 +23,9 @@ func WriteWithPadding(buffer *buf.Buffer, p []byte, command byte, userUUID *uuid
 	var paddingLen int32
 	if contentLen < 900 && paddingTLS {
 		log.Debugln("long padding")
-		paddingLen = rand.Int31n(500) + 900 - contentLen
+		paddingLen = fastrand.Int31n(500) + 900 - contentLen
 	} else {
-		paddingLen = rand.Int31n(256)
+		paddingLen = fastrand.Int31n(256)
 	}
 	if paddingLen > buf.BufferSize-21-contentLen {
 		paddingLen = buf.BufferSize - 21 - contentLen
@@ -48,9 +47,9 @@ func ApplyPadding(buffer *buf.Buffer, command byte, userUUID *uuid.UUID, padding
 	var paddingLen int32
 	if contentLen < 900 && paddingTLS {
 		log.Debugln("long padding")
-		paddingLen = rand.Int31n(500) + 900 - contentLen
+		paddingLen = fastrand.Int31n(500) + 900 - contentLen
 	} else {
-		paddingLen = rand.Int31n(256)
+		paddingLen = fastrand.Int31n(256)
 	}
 	if paddingLen > buf.BufferSize-21-contentLen {
 		paddingLen = buf.BufferSize - 21 - contentLen

transport/vmess/conn.go

@@ -11,17 +11,13 @@ import (
 	"errors"
 	"hash/fnv"
 	"io"
-	"math/rand"
 	"net"
 	"time"
 
+	"github.com/zhangyunhao116/fastrand"
 	"golang.org/x/crypto/chacha20poly1305"
 )
 
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}
-
 // Conn wrapper a net.Conn with vmess protocol
 type Conn struct {
 	net.Conn
@@ -76,7 +72,7 @@ func (vc *Conn) sendRequest() error {
 	buf.WriteByte(vc.respV)
 	buf.WriteByte(OptionChunkStream)
 
-	p := rand.Intn(16)
+	p := fastrand.Intn(16)
 	// P Sec Reserve Cmd
 	buf.WriteByte(byte(p<<4) | byte(vc.security))
 	buf.WriteByte(0)
@@ -94,7 +90,7 @@ func (vc *Conn) sendRequest() error {
 	// padding
 	if p > 0 {
 		padding := make([]byte, p)
-		rand.Read(padding)
+		fastrand.Read(padding)
 		buf.Write(padding)
 	}
 
@@ -200,7 +196,7 @@ func hashTimestamp(t time.Time) []byte {
 // newConn return a Conn instance
 func newConn(conn net.Conn, id *ID, dst *DstAddr, security Security, isAead bool) (*Conn, error) {
 	randBytes := make([]byte, 33)
-	rand.Read(randBytes)
+	fastrand.Read(randBytes)
 	reqBodyIV := make([]byte, 16)
 	reqBodyKey := make([]byte, 16)
 	copy(reqBodyIV[:], randBytes[:16])

transport/vmess/h2.go

@@ -2,11 +2,11 @@ package vmess
 
 import (
 	"io"
-	"math/rand"
 	"net"
 	"net/http"
 	"net/url"
 
+	"github.com/zhangyunhao116/fastrand"
 	"golang.org/x/net/http2"
 )
 
@@ -26,7 +26,7 @@ type H2Config struct {
 func (hc *h2Conn) establishConn() error {
 	preader, pwriter := io.Pipe()
 
-	host := hc.cfg.Hosts[rand.Intn(len(hc.cfg.Hosts))]
+	host := hc.cfg.Hosts[fastrand.Intn(len(hc.cfg.Hosts))]
 	path := hc.cfg.Path
 	// TODO: connect use VMess Host instead of H2 Host
 	req := http.Request{

transport/vmess/http.go

@@ -4,10 +4,11 @@ import (
 	"bufio"
 	"bytes"
 	"fmt"
-	"math/rand"
 	"net"
 	"net/http"
 	"net/textproto"
+
+	"github.com/zhangyunhao116/fastrand"
 )
 
 type httpConn struct {
@@ -51,16 +52,16 @@ func (hc *httpConn) Write(b []byte) (int, error) {
 		return hc.Conn.Write(b)
 	}
 
-	path := hc.cfg.Path[rand.Intn(len(hc.cfg.Path))]
+	path := hc.cfg.Path[fastrand.Intn(len(hc.cfg.Path))]
 	host := hc.cfg.Host
 	if header := hc.cfg.Headers["Host"]; len(header) != 0 {
-		host = header[rand.Intn(len(header))]
+		host = header[fastrand.Intn(len(header))]
 	}
 
 	u := fmt.Sprintf("http://%s%s", host, path)
 	req, _ := http.NewRequest("GET", u, bytes.NewBuffer(b))
 	for key, list := range hc.cfg.Headers {
-		req.Header.Set(key, list[rand.Intn(len(list))])
+		req.Header.Set(key, list[fastrand.Intn(len(list))])
 	}
 	req.ContentLength = int64(len(b))
 	if err := req.Write(hc.Conn); err != nil {

transport/vmess/vmess.go

@@ -2,12 +2,13 @@ package vmess
 
 import (
 	"fmt"
-	"github.com/Dreamacro/clash/common/utils"
-	"math/rand"
 	"net"
 	"runtime"
 
+	"github.com/Dreamacro/clash/common/utils"
+
 	"github.com/gofrs/uuid"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 // Version of vmess
@@ -77,7 +78,7 @@ type Config struct {
 
 // StreamConn return a Conn with net.Conn and DstAddr
 func (c *Client) StreamConn(conn net.Conn, dst *DstAddr) (net.Conn, error) {
-	r := rand.Intn(len(c.user))
+	r := fastrand.Intn(len(c.user))
 	return newConn(conn, c.user[r], dst, c.security, c.isAead)
 }
 

transport/vmess/websocket.go

@@ -8,9 +8,7 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
-
 	"io"
-	"math/rand"
 	"net"
 	"net/http"
 	"net/url"
@@ -22,7 +20,9 @@ import (
 	"github.com/Dreamacro/clash/common/buf"
 	N "github.com/Dreamacro/clash/common/net"
 	tlsC "github.com/Dreamacro/clash/component/tls"
+
 	"github.com/gorilla/websocket"
+	"github.com/zhangyunhao116/fastrand"
 )
 
 type websocketConn struct {
@@ -120,7 +120,7 @@ func (wsc *websocketConn) WriteBuffer(buffer *buf.Buffer) error {
 		binary.BigEndian.PutUint64(header[2:], uint64(dataLen))
 	}
 
-	maskKey := rand.Uint32()
+	maskKey := fastrand.Uint32()
 	binary.LittleEndian.PutUint32(header[1+payloadBitLength:], maskKey)
 	N.MaskWebSocket(maskKey, data)