shadowTLS/shadow/server.go
2022-09-05 14:21:33 +08:00

122 lines
2.4 KiB
Go

package shadow
import (
"fmt"
"io"
"net"
"time"
)
type Server struct {
ListenAddress string
TargetAddress string
FakeAddress string
}
func NewServer(listenAddress string, targetAddress string, fakeAddress string) *Server {
server := &Server{
ListenAddress: listenAddress,
TargetAddress: targetAddress,
FakeAddress: fakeAddress,
}
return server
}
func (s *Server) Start() {
listen, err := net.Listen("tcp", s.ListenAddress)
if err != nil {
fmt.Printf("[Server] Start server error: %v\n", err)
return
}
defer listen.Close()
fmt.Printf("[Server] Listening at:%v\n", s.ListenAddress)
for {
conn, err := listen.Accept()
if err != nil {
fmt.Printf("[Server] Accept error: %v\n", err)
continue
}
go handler(conn, s.TargetAddress, s.FakeAddress)
}
}
func handler(conn net.Conn, targetAddress string, fakeAddress string) {
//Process fake TLS handshake
fmt.Println("[Server] Perform handshake")
fakeConn, err := net.Dial("tcp", fakeAddress)
if err != nil {
fmt.Printf("[Server] Dial fake error : %v\n", err)
return
}
waitCh := make(chan int, 1)
go processHandshake(conn, fakeConn, waitCh)
go processHandshake(fakeConn, conn, waitCh)
<-waitCh
//Clean up previous buffered data
conn.SetDeadline(time.Now())
conn.SetDeadline(time.Time{})
realConnection, err := net.Dial("tcp", targetAddress)
if err != nil {
fmt.Printf("[Server] Dial target error : %v\n", err)
return
}
if err != nil {
return
}
p := &PackAppData{Conn: conn}
go io.Copy(realConnection, p)
go io.Copy(p, realConnection)
}
func processHandshake(src net.Conn, dst net.Conn, waitCh chan int) {
buf := make([]byte, 32*1024)
for {
nr, er := src.Read(buf)
if nr > 0 {
header := ParseAndVerifyTLSHeader(buf[0:nr])
nw, ew := dst.Write(buf[0:nr])
if header != nil && header.Type == ChangeCipherSpec {
//fmt.Println(header.toString())
fmt.Println("[Server] handshake complete")
if header.ChangeCipherSpecNext == AppData {
dst.Close()
waitCh <- 1
} else {
src.Close()
waitCh <- 1
return
}
break
}
if nw < 0 || nr < nw {
nw = 0
if ew == nil {
//fmt.Printf("ERR1 %v \n", ew)
}
}
if ew != nil {
//fmt.Printf("ERR2 %v \n", ew)
break
}
if nr != nw {
//fmt.Printf("ERR3 %v \n", "shortwrite")
break
}
}
if er != nil {
if er != io.EOF {
//fmt.Printf("ERR4 %v \n", er)
}
break
}
}
waitCh <- 1
}