mirror of
https://github.com/v2fly/v2ray-core.git
synced 2024-12-22 10:08:15 -05:00
363 lines
8.0 KiB
Go
363 lines
8.0 KiB
Go
// Package socks contains protocol definition and io lib for SOCKS5 protocol
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package socks
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import (
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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"github.com/v2ray/v2ray-core/log"
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v2net "github.com/v2ray/v2ray-core/net"
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)
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const (
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socksVersion = byte(0x05)
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socks4Version = byte(0x04)
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AuthNotRequired = byte(0x00)
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AuthGssApi = byte(0x01)
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AuthUserPass = byte(0x02)
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AuthNoMatchingMethod = byte(0xFF)
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Socks4RequestGranted = byte(90)
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Socks4RequestRejected = byte(91)
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)
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var (
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ErrorSocksVersion4 = errors.New("Using SOCKS version 4.")
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)
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// Authentication request header of Socks5 protocol
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type Socks5AuthenticationRequest struct {
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version byte
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nMethods byte
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authMethods [256]byte
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}
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type Socks4AuthenticationRequest struct {
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Version byte
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Command byte
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Port uint16
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IP [4]byte
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}
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func (request *Socks5AuthenticationRequest) HasAuthMethod(method byte) bool {
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for i := 0; i < int(request.nMethods); i++ {
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if request.authMethods[i] == method {
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return true
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}
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}
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return false
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}
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func ReadAuthentication(reader io.Reader) (auth Socks5AuthenticationRequest, auth4 Socks4AuthenticationRequest, err error) {
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buffer := make([]byte, 256)
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nBytes, err := reader.Read(buffer)
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if err != nil {
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log.Error("Failed to read socks authentication: %v", err)
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return
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}
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if nBytes < 2 {
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err = fmt.Errorf("Expected 2 bytes read, but actaully %d bytes read", nBytes)
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return
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}
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if buffer[0] == socks4Version {
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auth4.Version = buffer[0]
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auth4.Command = buffer[1]
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auth4.Port = binary.BigEndian.Uint16(buffer[2:4])
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copy(auth4.IP[:], buffer[4:8])
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err = ErrorSocksVersion4
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return
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}
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auth.version = buffer[0]
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if auth.version != socksVersion {
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err = fmt.Errorf("Unknown SOCKS version %d", auth.version)
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return
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}
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auth.nMethods = buffer[1]
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if auth.nMethods <= 0 {
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err = fmt.Errorf("Zero length of authentication methods")
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return
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}
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if nBytes-2 != int(auth.nMethods) {
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err = fmt.Errorf("Unmatching number of auth methods, expecting %d, but got %d", auth.nMethods, nBytes)
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return
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}
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copy(auth.authMethods[:], buffer[2:nBytes])
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return
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}
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type Socks5AuthenticationResponse struct {
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version byte
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authMethod byte
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}
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type Socks4AuthenticationResponse struct {
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result byte
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port uint16
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ip []byte
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}
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func NewAuthenticationResponse(authMethod byte) *Socks5AuthenticationResponse {
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return &Socks5AuthenticationResponse{
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version: socksVersion,
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authMethod: authMethod,
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}
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}
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func NewSocks4AuthenticationResponse(result byte, port uint16, ip []byte) *Socks4AuthenticationResponse {
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return &Socks4AuthenticationResponse{
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result: result,
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port: port,
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ip: ip,
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}
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}
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func WriteAuthentication(writer io.Writer, r *Socks5AuthenticationResponse) error {
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_, err := writer.Write([]byte{r.version, r.authMethod})
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return err
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}
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func WriteSocks4AuthenticationResponse(writer io.Writer, r *Socks4AuthenticationResponse) error {
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buffer := make([]byte, 8)
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// buffer[0] is always 0
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buffer[1] = r.result
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binary.BigEndian.PutUint16(buffer[2:4], r.port)
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copy(buffer[4:], r.ip)
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_, err := writer.Write(buffer)
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return err
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}
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type Socks5UserPassRequest struct {
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version byte
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username string
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password string
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}
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func (request Socks5UserPassRequest) IsValid(username string, password string) bool {
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return request.username == username && request.password == password
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}
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func ReadUserPassRequest(reader io.Reader) (request Socks5UserPassRequest, err error) {
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buffer := make([]byte, 256)
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_, err = reader.Read(buffer[0:2])
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if err != nil {
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return
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}
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request.version = buffer[0]
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nUsername := buffer[1]
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nBytes, err := reader.Read(buffer[:nUsername])
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if err != nil {
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return
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}
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request.username = string(buffer[:nBytes])
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_, err = reader.Read(buffer[0:1])
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if err != nil {
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return
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}
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nPassword := buffer[0]
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nBytes, err = reader.Read(buffer[:nPassword])
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if err != nil {
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return
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}
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request.password = string(buffer[:nBytes])
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return
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}
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type Socks5UserPassResponse struct {
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version byte
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status byte
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}
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func NewSocks5UserPassResponse(status byte) Socks5UserPassResponse {
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return Socks5UserPassResponse{
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version: socksVersion,
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status: status,
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}
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}
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func WriteUserPassResponse(writer io.Writer, response Socks5UserPassResponse) error {
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_, err := writer.Write([]byte{response.version, response.status})
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return err
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}
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const (
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AddrTypeIPv4 = byte(0x01)
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AddrTypeIPv6 = byte(0x04)
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AddrTypeDomain = byte(0x03)
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CmdConnect = byte(0x01)
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CmdBind = byte(0x02)
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CmdUdpAssociate = byte(0x03)
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)
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type Socks5Request struct {
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Version byte
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Command byte
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AddrType byte
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IPv4 [4]byte
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Domain string
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IPv6 [16]byte
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Port uint16
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}
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func ReadRequest(reader io.Reader) (request *Socks5Request, err error) {
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buffer := make([]byte, 4)
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nBytes, err := reader.Read(buffer)
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if err != nil {
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return
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}
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if nBytes < len(buffer) {
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err = fmt.Errorf("Unable to read request.")
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return
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}
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request = &Socks5Request{
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Version: buffer[0],
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Command: buffer[1],
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// buffer[2] is a reserved field
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AddrType: buffer[3],
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}
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switch request.AddrType {
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case AddrTypeIPv4:
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nBytes, err = reader.Read(request.IPv4[:])
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if err != nil {
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return
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}
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if nBytes != 4 {
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err = fmt.Errorf("Unable to read IPv4 address.")
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return
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}
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case AddrTypeDomain:
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buffer = make([]byte, 256)
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nBytes, err = reader.Read(buffer[0:1])
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if err != nil {
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return
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}
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domainLength := buffer[0]
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nBytes, err = reader.Read(buffer[:domainLength])
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if err != nil {
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return
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}
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if nBytes != int(domainLength) {
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err = fmt.Errorf("Unable to read domain with %d bytes, expecting %d bytes", nBytes, domainLength)
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return
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}
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request.Domain = string(buffer[:domainLength])
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case AddrTypeIPv6:
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nBytes, err = reader.Read(request.IPv6[:])
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if err != nil {
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return
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}
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if nBytes != 16 {
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err = fmt.Errorf("Unable to read IPv4 address.")
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return
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}
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default:
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err = fmt.Errorf("Unexpected address type %d", request.AddrType)
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return
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}
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buffer = make([]byte, 2)
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nBytes, err = reader.Read(buffer)
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if err != nil {
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return
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}
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if nBytes != 2 {
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err = fmt.Errorf("Unable to read port.")
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return
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}
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request.Port = binary.BigEndian.Uint16(buffer)
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return
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}
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func (request *Socks5Request) Destination() v2net.Address {
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switch request.AddrType {
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case AddrTypeIPv4:
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return v2net.IPAddress(request.IPv4[:], request.Port)
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case AddrTypeIPv6:
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return v2net.IPAddress(request.IPv6[:], request.Port)
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case AddrTypeDomain:
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return v2net.DomainAddress(request.Domain, request.Port)
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default:
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panic("Unknown address type")
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}
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}
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const (
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ErrorSuccess = byte(0x00)
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ErrorGeneralFailure = byte(0x01)
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ErrorConnectionNotAllowed = byte(0x02)
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ErrorNetworkUnreachable = byte(0x03)
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ErrorHostUnUnreachable = byte(0x04)
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ErrorConnectionRefused = byte(0x05)
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ErrorTTLExpired = byte(0x06)
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ErrorCommandNotSupported = byte(0x07)
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ErrorAddressTypeNotSupported = byte(0x08)
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)
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type Socks5Response struct {
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Version byte
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Error byte
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AddrType byte
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IPv4 [4]byte
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Domain string
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IPv6 [16]byte
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Port uint16
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}
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func NewSocks5Response() *Socks5Response {
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return &Socks5Response{
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Version: socksVersion,
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}
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}
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func (r *Socks5Response) SetIPv4(ipv4 []byte) {
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r.AddrType = AddrTypeIPv4
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copy(r.IPv4[:], ipv4)
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}
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func (r *Socks5Response) SetIPv6(ipv6 []byte) {
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r.AddrType = AddrTypeIPv6
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copy(r.IPv6[:], ipv6)
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}
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func (r *Socks5Response) SetDomain(domain string) {
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r.AddrType = AddrTypeDomain
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r.Domain = domain
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}
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func (r *Socks5Response) toBytes() []byte {
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buffer := make([]byte, 0, 300)
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buffer = append(buffer, r.Version)
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buffer = append(buffer, r.Error)
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buffer = append(buffer, 0x00) // reserved
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buffer = append(buffer, r.AddrType)
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switch r.AddrType {
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case 0x01:
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buffer = append(buffer, r.IPv4[:]...)
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case 0x03:
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buffer = append(buffer, byte(len(r.Domain)))
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buffer = append(buffer, []byte(r.Domain)...)
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case 0x04:
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buffer = append(buffer, r.IPv6[:]...)
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}
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portBuffer := make([]byte, 2)
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binary.BigEndian.PutUint16(portBuffer, r.Port)
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buffer = append(buffer, portBuffer...)
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return buffer
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}
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func WriteResponse(writer io.Writer, response *Socks5Response) error {
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_, err := writer.Write(response.toBytes())
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return err
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}
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