shadowTLS/shadow/server.go

132 lines
2.8 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, "client")
go processHandshake(fakeConn, conn, waitCh, "server")
<-waitCh
//Clean up previous buffered data
conn.SetDeadline(time.Now())
conn.SetDeadline(time.Time{})
fakeConn.Close()
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}
defer p.Close()
defer realConnection.Close()
exit := make(chan int, 1)
go MyCopy(p, realConnection, exit)
go MyCopy(realConnection, p, exit)
<-exit
}
func processHandshake(src net.Conn, dst net.Conn, waitCh chan int, srcType string) {
buf := make([]byte, 32*1024)
verifyPass := false
for {
nr, er := src.Read(buf)
if nr > 0 {
nw, ew := dst.Write(buf[0:nr])
if srcType == "client" {
header := ParseAndVerifyTLSHeader(buf[0:nr])
if header != nil {
if header != nil && header.Type == Handshake && header.HandshakeType == ClientHello && !verifyPass {
verifyPass = VerifyKey(header.Rand, HandshakePassword)
}
if header.Type == ChangeCipherSpec {
if HandshakePassword != "" && !verifyPass {
fmt.Println("[Server] Probe detected,pass through all traffic.")
} else {
fmt.Println("[Server] handshake complete")
waitCh <- 1
break
}
}
//fmt.Println(header.toString())
}
}
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
}
}
}