Golang Buffer.Append方法代码示例

func (request *Socks5UDPRequest) Write(buffer *alloc.Buffer) {
	buffer.AppendBytes(0, 0, request.Fragment)
	switch {
	case request.Address.IsIPv4():
		buffer.AppendBytes(AddrTypeIPv4).Append(request.Address.IP())
	case request.Address.IsIPv6():
		buffer.AppendBytes(AddrTypeIPv6).Append(request.Address.IP())
	case request.Address.IsDomain():
		buffer.AppendBytes(AddrTypeDomain, byte(len(request.Address.Domain()))).Append([]byte(request.Address.Domain()))
	}
	buffer.Append(request.Port.Bytes())
	buffer.Append(request.Data.Value)
}

func (this *VMessInboundHandler) generateCommand(buffer *alloc.Buffer) {
	cmd := byte(0)
	commandBytes := alloc.NewSmallBuffer().Clear()
	defer commandBytes.Release()

	if this.features != nil && this.features.Detour != nil {

		tag := this.features.Detour.ToTag
		if this.space.HasInboundHandlerManager() {
			handlerManager := this.space.InboundHandlerManager()
			handler, availableMin := handlerManager.GetHandler(tag)
			inboundHandler, ok := handler.(*VMessInboundHandler)
			if ok {
				if availableMin > 255 {
					availableMin = 255
				}
				cmd = byte(1)
				log.Info("VMessIn: Pick detour handler for port ", inboundHandler.Port(), " for ", availableMin, " minutes.")
				user := inboundHandler.GetUser()
				saCmd := &command.SwitchAccount{
					Port:     inboundHandler.Port(),
					ID:       user.ID.UUID(),
					AlterIds: serial.Uint16Literal(len(user.AlterIDs)),
					Level:    user.Level,
					ValidMin: byte(availableMin),
				}
				saCmd.Marshal(commandBytes)
			}
		}
	}

	if cmd == 0 || commandBytes.Len()+4 > 256 {
		buffer.AppendBytes(byte(0), byte(0))
	} else {
		buffer.AppendBytes(cmd, byte(commandBytes.Len()+4))
		fnv1hash := fnv.New32a()
		fnv1hash.Write(commandBytes.Value)
		hashValue := fnv1hash.Sum32()
		buffer.AppendBytes(byte(hashValue>>24), byte(hashValue>>16), byte(hashValue>>8), byte(hashValue))
		buffer.Append(commandBytes.Value)
	}
}

func (r *Socks5Response) Write(buffer *alloc.Buffer) {
	buffer.AppendBytes(r.Version, r.Error, 0x00 /* reserved */, r.AddrType)
	switch r.AddrType {
	case 0x01:
		buffer.Append(r.IPv4[:])
	case 0x03:
		buffer.AppendBytes(byte(len(r.Domain)))
		buffer.Append([]byte(r.Domain))
	case 0x04:
		buffer.Append(r.IPv6[:])
	}
	buffer.Append(r.Port.Bytes())
}

func (this *VMessInboundHandler) generateCommand(buffer *alloc.Buffer) {
	cmd := byte(0)
	commandBytes := alloc.NewSmallBuffer().Clear()
	defer commandBytes.Release()

	if this.features != nil && this.features.Detour != nil {
		tag := this.features.Detour.ToTag
		if this.space.HasInboundHandlerManager() {
			handlerManager := this.space.InboundHandlerManager()
			handler, availableSec := handlerManager.GetHandler(tag)
			inboundHandler, ok := handler.(*VMessInboundHandler)
			if ok {
				user := inboundHandler.GetUser()
				availableMin := availableSec / 60
				if availableMin > 255 {
					availableMin = 255
				}

				saCmd := &command.SwitchAccount{
					Port:     inboundHandler.Port(),
					ID:       user.ID.UUID(),
					AlterIds: serial.Uint16Literal(len(user.AlterIDs)),
					Level:    user.Level,
					ValidMin: byte(availableMin),
				}
				saCmd.Marshal(commandBytes)
			}
		}
	}

	if commandBytes.Len() > 256 {
		buffer.AppendBytes(byte(0), byte(0))
	} else {
		buffer.AppendBytes(cmd, byte(commandBytes.Len()))
		buffer.Append(commandBytes.Value)
	}
}

// ToBytes returns a VMessRequest in the form of byte array.
func (this *VMessRequest) ToBytes(timestampGenerator RandomTimestampGenerator, buffer *alloc.Buffer) (*alloc.Buffer, error) {
	if buffer == nil {
		buffer = alloc.NewSmallBuffer().Clear()
	}

	timestamp := timestampGenerator.Next()
	idHash := IDHash(this.User.AnyValidID().Bytes())
	idHash.Write(timestamp.Bytes())

	hashStart := buffer.Len()
	buffer.Slice(0, hashStart+16)
	idHash.Sum(buffer.Value[hashStart:hashStart])

	encryptionBegin := buffer.Len()

	buffer.AppendBytes(this.Version)
	buffer.Append(this.RequestIV)
	buffer.Append(this.RequestKey)
	buffer.AppendBytes(this.ResponseHeader, this.Option, byte(0), byte(0))
	buffer.AppendBytes(this.Command)
	buffer.Append(this.Port.Bytes())

	switch {
	case this.Address.IsIPv4():
		buffer.AppendBytes(addrTypeIPv4)
		buffer.Append(this.Address.IP())
	case this.Address.IsIPv6():
		buffer.AppendBytes(addrTypeIPv6)
		buffer.Append(this.Address.IP())
	case this.Address.IsDomain():
		buffer.AppendBytes(addrTypeDomain, byte(len(this.Address.Domain())))
		buffer.Append([]byte(this.Address.Domain()))
	}

	encryptionEnd := buffer.Len()

	fnv1a := fnv.New32a()
	fnv1a.Write(buffer.Value[encryptionBegin:encryptionEnd])

	fnvHash := fnv1a.Sum32()
	buffer.AppendBytes(byte(fnvHash>>24), byte(fnvHash>>16), byte(fnvHash>>8), byte(fnvHash))
	encryptionEnd += 4

	timestampHash := md5.New()
	timestampHash.Write(timestamp.HashBytes())
	iv := timestampHash.Sum(nil)
	aesStream, err := v2crypto.NewAesEncryptionStream(this.User.ID.CmdKey(), iv)
	if err != nil {
		return nil, err
	}
	aesStream.XORKeyStream(buffer.Value[encryptionBegin:encryptionEnd], buffer.Value[encryptionBegin:encryptionEnd])

	return buffer, nil
}

// ToBytes returns a VMessRequest in the form of byte array.
func (request *VMessRequest) ToBytes(idHash user.CounterHash, randomRangeInt64 user.RandomInt64InRange, buffer *alloc.Buffer) (*alloc.Buffer, error) {
	if buffer == nil {
		buffer = alloc.NewSmallBuffer().Clear()
	}

	counter := randomRangeInt64(time.Now().UTC().Unix(), 30)
	hash := idHash.Hash(request.UserId.Bytes[:], counter)

	buffer.Append(hash)

	encryptionBegin := buffer.Len()

	buffer.AppendBytes(request.Version)
	buffer.Append(request.RequestIV)
	buffer.Append(request.RequestKey)
	buffer.Append(request.ResponseHeader)
	buffer.AppendBytes(request.Command)
	buffer.Append(request.Address.PortBytes())

	switch {
	case request.Address.IsIPv4():
		buffer.AppendBytes(addrTypeIPv4)
		buffer.Append(request.Address.IP())
	case request.Address.IsIPv6():
		buffer.AppendBytes(addrTypeIPv6)
		buffer.Append(request.Address.IP())
	case request.Address.IsDomain():
		buffer.AppendBytes(addrTypeDomain, byte(len(request.Address.Domain())))
		buffer.Append([]byte(request.Address.Domain()))
	}

	encryptionEnd := buffer.Len()

	fnv1a := fnv.New32a()
	fnv1a.Write(buffer.Value[encryptionBegin:encryptionEnd])

	fnvHash := fnv1a.Sum32()
	buffer.AppendBytes(byte(fnvHash>>24), byte(fnvHash>>16), byte(fnvHash>>8), byte(fnvHash))
	encryptionEnd += 4

	aesCipher, err := aes.NewCipher(request.UserId.CmdKey())
	if err != nil {
		return nil, err
	}
	aesStream := cipher.NewCFBEncrypter(aesCipher, user.Int64Hash(counter))
	aesStream.XORKeyStream(buffer.Value[encryptionBegin:encryptionEnd], buffer.Value[encryptionBegin:encryptionEnd])

	return buffer, nil
}