Slice operations optimisation

gqclient/TLS/TLS.go

@@ -10,9 +10,11 @@ import (
 func AddRecordLayer(input []byte, typ []byte, ver []byte) []byte {
  length := make([]byte, 2)
  binary.BigEndian.PutUint16(length, uint16(len(input)))
- ret := append(typ, ver...)
- ret = append(ret, length...)
- ret = append(ret, input...)
+ ret := make([]byte, 5+len(input))
+ copy(ret[0:1], typ)
+ copy(ret[1:3], ver)
+ copy(ret[3:5], length)
+ copy(ret[5:], input)
  return ret
 }
 
@@ -29,15 +31,17 @@ type browser interface {
 
 func makeServerName(sta *gqclient.State) []byte {
  serverName := sta.ServerName
+ serverNameListLength := make([]byte, 2)
+ binary.BigEndian.PutUint16(serverNameListLength, uint16(len(serverName)+3))
+ serverNameType := []byte{0x00} // host_name
  serverNameLength := make([]byte, 2)
  binary.BigEndian.PutUint16(serverNameLength, uint16(len(serverName)))
- serverNameType := []byte{0x00} // host_name
- var ret []byte
- ret = append(serverNameType, serverNameLength...)
- ret = append(ret, serverName...)
- serverNameListLength := make([]byte, 2)
- binary.BigEndian.PutUint16(serverNameListLength, uint16(len(ret)))
- return append(serverNameListLength, ret...)
+ ret := make([]byte, 2+1+2+len(serverName))
+ copy(ret[0:2], serverNameListLength)
+ copy(ret[2:3], serverNameType)
+ copy(ret[3:5], serverNameLength)
+ copy(ret[5:], serverName)
+ return ret
 }
 
 func makeSessionTicket(sta *gqclient.State) []byte {
@@ -46,9 +50,9 @@ func makeSessionTicket(sta *gqclient.State) []byte {
 }
 
 func makeNullBytes(length int) []byte {
- var ret []byte
+ ret := make([]byte, length)
  for i := 0; i < length; i++ {
- ret = append(ret, 0x00)
+ ret[i] = 0x00
  }
  return ret
 }
@@ -57,9 +61,11 @@ func makeNullBytes(length int) []byte {
 func addExtRec(typ []byte, data []byte) []byte {
  length := make([]byte, 2)
  binary.BigEndian.PutUint16(length, uint16(len(data)))
- var ret []byte
- ret = append(typ, length...)
- return append(ret, data...)
+ ret := make([]byte, 2+2+len(data))
+ copy(ret[0:2], typ)
+ copy(ret[2:4], length)
+ copy(ret[4:], data)
+ return ret
 }
 
 // ComposeInitHandshake composes ClientHello with record layer

gqclient/TLS/chrome.go

@@ -26,8 +26,11 @@ func (c *chrome) composeExtensions(sta *gqclient.State) []byte {
 
  makeSupportedGroups := func() []byte {
  suppGroupListLen := []byte{0x00, 0x08}
- suppGroup := append(makeGREASE(), []byte{0x00, 0x1d, 0x00, 0x17, 0x00, 0x18}...)
- return append(suppGroupListLen, suppGroup...)
+ ret := make([]byte, 2+8)
+ copy(ret[0:2], suppGroupListLen)
+ copy(ret[2:4], makeGREASE())
+ copy(ret[4:], []byte{0x00, 0x1d, 0x00, 0x17, 0x00, 0x18})
+ return ret
  }
 
  var ext [14][]byte

gqclient/auth.go

@@ -23,5 +23,8 @@ func MakeRandomField(sta *State) []byte {
  goal := h.Sum(nil)[0:16]
  iv := CryptoRandBytes(16)
  rest := encrypt(iv, sta.AESKey, goal)
- return append(iv, rest...)
+ ret := make([]byte, 32)
+ copy(ret, iv)
+ copy(ret[16:], rest)
+ return ret
 }

gqclient/util.go

@@ -24,24 +24,26 @@ func BtoInt(b []byte) int {
 }
 
 // CryptoRandBytes generates a byte slice filled with cryptographically secure random bytes
-func CryptoRandBytes(length int) (ret []byte) {
+func CryptoRandBytes(length int) []byte {
  byteMax := big.NewInt(int64(256))
- for len(ret) < length {
+ ret := make([]byte, length)
+ for i := 0; i < length; i++ {
  randInt, _ := rand.Int(rand.Reader, byteMax)
  randByte := byte(randInt.Int64())
- ret = append(ret, randByte)
+ ret[i] = randByte
  }
- return
+ return ret
 }
 
 // PsudoRandBytes returns a byte slice filled with psudorandom bytes generated by the seed
-func PsudoRandBytes(length int, seed int64) (ret []byte) {
+func PsudoRandBytes(length int, seed int64) []byte {
  prand.Seed(seed)
- for len(ret) < length {
+ ret := make([]byte, length)
+ for i := 0; i < length; i++ {
  randByte := byte(prand.Intn(256))
- ret = append(ret, randByte)
+ ret[i] = randByte
  }
- return
+ return ret
 }
 
 // ReadTillDrain reads TLS data according to its record layer

gqserver/TLS.go

@@ -48,9 +48,11 @@ func parseExtensions(input []byte) (ret map[[2]byte][]byte, err error) {
 func AddRecordLayer(input []byte, typ []byte, ver []byte) []byte {
  length := make([]byte, 2)
  binary.BigEndian.PutUint16(length, uint16(len(input)))
- ret := append(typ, ver...)
- ret = append(ret, length...)
- ret = append(ret, input...)
+ ret := make([]byte, 5+len(input))
+ copy(ret[0:1], typ)
+ copy(ret[1:3], ver)
+ copy(ret[3:5], length)
+ copy(ret[5:], input)
  return ret
 }
 

gqserver/util.go

@@ -22,13 +22,14 @@ func BtoInt(b []byte) int {
 }
 
 // PsudoRandBytes returns a byte slice filled with psudorandom bytes generated by the seed
-func PsudoRandBytes(length int, seed int64) (ret []byte) {
+func PsudoRandBytes(length int, seed int64) []byte {
  prand.Seed(seed)
- for len(ret) < length {
+ ret := make([]byte, length)
+ for i := 0; i < length; i++ {
  randByte := byte(prand.Intn(256))
- ret = append(ret, randByte)
+ ret[i] = randByte
  }
- return
+ return ret
 }
 
 // ReadTillDrain reads TLS data according to its record layer