/
socks5.go
322 lines (290 loc) · 8.61 KB
/
socks5.go
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package fly
import (
"bytes"
"crypto/sha1"
"fmt"
"github.com/xtaci/kcp-go"
"golang.org/x/crypto/pbkdf2"
"io"
"net"
"strconv"
"strings"
)
func StartSocks5(port string) {
listener := ListenTCP(port)
for {
client, err := listener.Accept()
if err != nil {
logger.Println("accept failed!")
continue
}
logger.Println("client accepted!")
go handleLocalClient(client)
}
}
func handleLocalClient(client net.Conn) {
data := make([]byte, 1024)
n, err := client.Read(data[:])
if err != nil {
logger.Println("read error!")
return
}
if data[0] == 0x05 {
// response the success of handshake to client
_, err = client.Write([]byte{0x05, 0x00})
if err != nil {
logger.Println("response to client failed!")
return
}
// read the detail request from client
n, err = client.Read(data[:])
if err != nil {
logger.Println("read from client failed --->", err)
return
} else if n < 7 {
logger.Println("read error of request length --->", data[:n])
return
}
var host, port = parseSocksRequest(data, n)
logger.Printf("start request %s:%s\n", host, port)
// request to the target server
server, err := net.Dial("tcp", net.JoinHostPort(host, port))
if err != nil {
CheckError(err, "request to the target server failed!")
return
}
// response request success to client
by := []byte{0x05, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
_, err = client.Write(by)
CheckError(err, "response 'request success' to client failed!")
go io.Copy(server, client)
io.Copy(client, server)
}
}
func Socks5ForClientByTCP(localPort, serverAddr, method, key string, pacMode bool) {
listener := ListenTCP(localPort)
cipherEntity := CipherMap[method]
if cipherEntity == nil {
logger.Println("encrypt method: aes-256-cfb")
} else {
logger.Println("encrypt method:", method)
}
if pacMode {
GetPAC()
logger.Printf("pac mode is on, the url is: http://localhost:%s/flynet.pac\n", localPort)
}
for {
client, err := listener.Accept()
if err != nil {
logger.Println("accept failed --->", err)
continue
}
logger.Println("client accepted!")
go func() {
buff := make([]byte, 1024)
n, err := client.Read(buff)
if err != nil {
logger.Println("read handshake request failed --->", err)
return
}
if buff[0] == 0x05 {
if n, err = client.Write([]byte{0x05, 0x00}); err != nil {
logger.Println("write handshake response failed --->", err)
return
}
// read detail request
//if n, err = client.Read(buff); err != nil {
if n, err = io.ReadAtLeast(client, buff, 5); err != nil {
logger.Println("read client quest failed --->", err)
return
}
replyBy := []byte{0x05, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
if _, err = client.Write(replyBy); err != nil {
logger.Println("write 'request success' failed --->", err)
return
}
//
// +----+-----+-------+------+----------+----------+
// |VER | CMD | RSV | ATYP | DST.ADDR | DST.PORT |
// +----+-----+-------+------+----------+----------+
// | 1 | 1 | X'00' | 1 | Variable | 2 |
// +----+-----+-------+------+----------+----------+
//
server := DialWithAddr(serverAddr, method, key, buff[:n])
if server == nil {
return
}
go RelayTraffic(server, client)
RelayTraffic(client, server)
} else {
if pacMode {
handlePACRequest(client, buff[:n], localPort)
}
}
}()
}
}
func Socks5ForServerByTCP(localPort, method, key string) {
listener := ListenTCP(localPort)
cipherEntity := CipherMap[method]
if cipherEntity == nil {
logger.Println("encrypt method: aes-256-cfb")
} else {
logger.Println("encrypt method:", method)
}
for {
logger.Println("waiting...")
client, err := listener.Accept()
if err != nil {
logger.Println("server accept failed --->", err)
continue
}
go func() {
buff := make([]byte, 1024)
conn := NewConn(client, NewCipherInstance(key, method))
n, err := conn.Read(buff)
if err != nil {
logger.Println("read target address failed --->", err)
return
} else if n < 7 {
logger.Println("read error of request length --->", buff[:n])
return
}
host, port := parseSocksRequest(buff[:n], n)
//logger.Printf("target server ------\n%s:%s\n------\n%d\n+++++++\n", host, port, buff[:n])
logger.Printf("target server: %s:%s\n", host, port)
// dial the target server
server, err := net.Dial("tcp", net.JoinHostPort(host, port))
if err != nil {
logger.Println("dial target server failed --->", err)
return
}
go RelayTraffic(server, conn)
RelayTraffic(conn, server)
}()
}
}
func Socks5ForClientByUDP(localPort, serverAddr string) {
listener := ListenTCP(localPort)
for {
con, err := listener.Accept()
if err != nil {
logger.Println("accept error --->", err)
continue
}
logger.Println("client accepted.")
go func() {
var b [1024] byte
_, err := con.Read(b[:])
if err != nil {
logger.Println("read error --->", err)
return
}
if b[0] == 0x05 {
_, _ = con.Write([]byte{0x05, 0x00})
// kcp can't resolve addr such as ":8080"
if strings.HasPrefix(serverAddr, ":") {
serverAddr = "127.0.0.1" + serverAddr
}
key := pbkdf2.Key([]byte("fly"), []byte("asche910"), 1024, 32, sha1.New)
block, _ := kcp.NewAESBlockCrypt(key)
session, err := kcp.DialWithOptions(serverAddr, block, 10, 3)
if err != nil {
logger.Println("connect targetServer failed --->", err)
return
}
go TCPToUDP(session, con)
UDPToTCP(con, session)
}
}()
}
}
func Socks5ForServerByUDP(localPort string) {
key := pbkdf2.Key([]byte("fly"), []byte("asche910"), 1024, 32, sha1.New)
block, _ := kcp.NewAESBlockCrypt(key)
if listener, err := kcp.ListenWithOptions(":"+localPort, block, 10, 3); err == nil {
logger.Printf("server listent udp at %s\n", localPort)
for {
con, err := listener.AcceptKCP()
if err != nil {
logger.Fatal(err)
}
go func() {
data := make([]byte, 1024)
n, err := con.Read(data)
if err != nil {
logger.Println("read target address failed --->", err)
return
} else if n < 7 {
logger.Println("read error of request length --->", data[:n])
return
}
//logger.Println(string(data[:n]))
if data[0] == 5 && data[1] == 1 && data[2] == 0 {
var host, port = parseSocksRequest(data, n)
// request to the target server
server, err := net.Dial("tcp", net.JoinHostPort(host, port))
logger.Printf("request remote %s:%s\n", host, port)
if err != nil {
logger.Println("dial failed!")
CheckError(err, "dial remote failed!")
return
}
// response request success to client
by := []byte{0x05, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
n, err = con.Write(by)
if err != nil {
logger.Println("response to client failed! ", err)
return
}
go UDPToTCP(server, con)
TCPToUDP(con, server)
} else {
logger.Println("unrecognized protocol!")
return
}
}()
}
} else {
logger.Panicln(err)
}
}
// parse socks5 request for target host and port
func parseSocksRequest(data []byte, n int) (string, string) {
// TODO sometimes there are some nums, such as '22 3 1 2 0 1 0 1 252...' after port. why?
var host, port string
var p1, p2 byte
switch data[3] {
case 0x01: // IPV4 address
host = net.IPv4(data[4], data[5], data[6], data[7]).String()
p1 = data[8]
p2 = data[9]
case 0x03: // domain
host = string(data[5 : 5+data[4]]) // data[4] stands for the length of domain
p1 = data[data[4]+5]
p2 = data[data[4]+6]
case 0x04: // IPV6 address
host = net.IP{data[4], data[5], data[6], data[7], data[8], data[9], data[10], data[11], data[12], data[13], data[14], data[15], data[16], data[17], data[18], data[19]}.String()
p1 = data[20]
p2 = data[21]
}
port = strconv.Itoa(int(p1)<<8 | int(p2))
return host, port
}
func handlePACRequest(conn net.Conn, buff []byte, port string) {
if bytes.Contains(buff[:], []byte("flynet.pac HTTP")) {
fileBuff, size := GetPAC()
// replace the socks5 port of pac file with the port user choose
fileBuff = bytes.Replace(fileBuff[:size], []byte("SOCKS5 127.0.0.1:1080"), []byte("SOCKS5 127.0.0.1:"+port), 1)
_, _ = conn.Write([]byte(fmt.Sprintf("HTTP/1.1 200 OK\r\n"+
"Content-Type: application/x-ns-proxy-autoconfig\r\n"+
"Server: flynet\r\nContent-Length: %d\r\n\r\n", size)))
_, _ = conn.Write(fileBuff[:size])
} else {
msg := "hello,flynet!"
_, _ = conn.Write([]byte(fmt.Sprintf("HTTP/1.1 200 OK\r\n"+
"Content-Type: text/html; charset=utf-8\r\n"+
"Server: flynet\r\nContent-Length: %d\r\n\r\n%s", len(msg), msg)))
}
conn.Close()
}