/
handshake.go
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/
handshake.go
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package socks
import (
"context"
"io"
"net"
"net/netip"
"os"
"github.com/MehranF123/sing/common"
"github.com/MehranF123/sing/common/auth"
E "github.com/MehranF123/sing/common/exceptions"
M "github.com/MehranF123/sing/common/metadata"
N "github.com/MehranF123/sing/common/network"
"github.com/MehranF123/sing/common/rw"
"github.com/MehranF123/sing/protocol/socks/socks4"
"github.com/MehranF123/sing/protocol/socks/socks5"
)
type Handler interface {
N.TCPConnectionHandler
N.UDPConnectionHandler
}
func ClientHandshake4(conn io.ReadWriter, command byte, destination M.Socksaddr, username string) (socks4.Response, error) {
err := socks4.WriteRequest(conn, socks4.Request{
Command: command,
Destination: destination,
Username: username,
})
if err != nil {
return socks4.Response{}, err
}
response, err := socks4.ReadResponse(conn)
if err != nil {
return socks4.Response{}, err
}
if response.ReplyCode != socks4.ReplyCodeGranted {
err = E.New("socks4: request rejected, code= ", response.ReplyCode)
}
return response, err
}
func ClientHandshake5(conn io.ReadWriter, command byte, destination M.Socksaddr, username string, password string) (socks5.Response, error) {
var method byte
if username == "" {
method = socks5.AuthTypeNotRequired
} else {
method = socks5.AuthTypeUsernamePassword
}
err := socks5.WriteAuthRequest(conn, socks5.AuthRequest{
Methods: []byte{method},
})
if err != nil {
return socks5.Response{}, err
}
authResponse, err := socks5.ReadAuthResponse(conn)
if err != nil {
return socks5.Response{}, err
}
if authResponse.Method == socks5.AuthTypeUsernamePassword {
err = socks5.WriteUsernamePasswordAuthRequest(conn, socks5.UsernamePasswordAuthRequest{
Username: username,
Password: password,
})
if err != nil {
return socks5.Response{}, err
}
usernamePasswordResponse, err := socks5.ReadUsernamePasswordAuthResponse(conn)
if err != nil {
return socks5.Response{}, err
}
if usernamePasswordResponse.Status != socks5.UsernamePasswordStatusSuccess {
return socks5.Response{}, E.New("socks5: incorrect user name or password")
}
} else if authResponse.Method != socks5.AuthTypeNotRequired {
return socks5.Response{}, E.New("socks5: unsupported auth method: ", authResponse.Method)
}
err = socks5.WriteRequest(conn, socks5.Request{
Command: command,
Destination: destination,
})
if err != nil {
return socks5.Response{}, err
}
response, err := socks5.ReadResponse(conn)
if err != nil {
return socks5.Response{}, err
}
if response.ReplyCode != socks5.ReplyCodeSuccess {
err = E.New("socks5: request rejected, code=", response.ReplyCode)
}
return response, err
}
func HandleConnection(ctx context.Context, conn net.Conn, authenticator auth.Authenticator, handler Handler, metadata M.Metadata) error {
version, err := rw.ReadByte(conn)
if err != nil {
return err
}
return HandleConnection0(ctx, conn, version, authenticator, handler, metadata)
}
func HandleConnection0(ctx context.Context, conn net.Conn, version byte, authenticator auth.Authenticator, handler Handler, metadata M.Metadata) error {
switch version {
case socks4.Version:
request, err := socks4.ReadRequest0(conn)
if err != nil {
return err
}
switch request.Command {
case socks4.CommandConnect:
responseAddr := request.Destination
if !responseAddr.IsIPv4() {
responseAddr = M.SocksaddrFrom(netip.IPv4Unspecified(), responseAddr.Port)
}
err = socks4.WriteResponse(conn, socks4.Response{
ReplyCode: socks4.ReplyCodeGranted,
Destination: responseAddr,
})
if err != nil {
return err
}
metadata.Protocol = "socks4"
metadata.Destination = request.Destination
return handler.NewConnection(auth.ContextWithUser(ctx, request.Username), conn, metadata)
default:
err = socks4.WriteResponse(conn, socks4.Response{
ReplyCode: socks4.ReplyCodeRejectedOrFailed,
Destination: request.Destination,
})
if err != nil {
return err
}
return E.New("socks4: unsupported command ", request.Command)
}
case socks5.Version:
authRequest, err := socks5.ReadAuthRequest0(conn)
if err != nil {
return err
}
var authMethod byte
if authenticator != nil && !common.Contains(authRequest.Methods, socks5.AuthTypeUsernamePassword) {
err = socks5.WriteAuthResponse(conn, socks5.AuthResponse{
Method: socks5.AuthTypeNoAcceptedMethods,
})
if err != nil {
return err
}
}
if authenticator != nil {
authMethod = socks5.AuthTypeUsernamePassword
} else {
authMethod = socks5.AuthTypeNotRequired
}
err = socks5.WriteAuthResponse(conn, socks5.AuthResponse{
Method: authMethod,
})
if err != nil {
return err
}
if authMethod == socks5.AuthTypeUsernamePassword {
usernamePasswordAuthRequest, err := socks5.ReadUsernamePasswordAuthRequest(conn)
if err != nil {
return err
}
ctx = auth.ContextWithUser(ctx, usernamePasswordAuthRequest.Username)
response := socks5.UsernamePasswordAuthResponse{}
if authenticator.Verify(usernamePasswordAuthRequest.Username, usernamePasswordAuthRequest.Password) {
response.Status = socks5.UsernamePasswordStatusSuccess
} else {
response.Status = socks5.UsernamePasswordStatusFailure
}
err = socks5.WriteUsernamePasswordAuthResponse(conn, response)
if err != nil {
return err
}
}
request, err := socks5.ReadRequest(conn)
if err != nil {
return err
}
switch request.Command {
case socks5.CommandConnect:
err = socks5.WriteResponse(conn, socks5.Response{
ReplyCode: socks5.ReplyCodeSuccess,
Bind: request.Destination,
})
if err != nil {
return err
}
metadata.Protocol = "socks5"
metadata.Destination = request.Destination
return handler.NewConnection(ctx, conn, metadata)
case socks5.CommandUDPAssociate:
var udpConn *net.UDPConn
udpConn, err = net.ListenUDP(M.NetworkFromNetAddr("udp", M.AddrFromNetAddr(conn.LocalAddr())), net.UDPAddrFromAddrPort(netip.AddrPortFrom(M.AddrFromNetAddr(conn.LocalAddr()), 0)))
if err != nil {
return err
}
defer udpConn.Close()
err = socks5.WriteResponse(conn, socks5.Response{
ReplyCode: socks5.ReplyCodeSuccess,
Bind: M.SocksaddrFromNet(udpConn.LocalAddr()),
})
if err != nil {
return err
}
metadata.Protocol = "socks5"
metadata.Destination = request.Destination
var innerError error
done := make(chan struct{})
go func() {
defer conn.Close()
innerError = handler.NewPacketConnection(ctx, NewAssociatePacketConn(udpConn, request.Destination, conn), metadata)
close(done)
}()
err = common.Error(io.Copy(io.Discard, conn))
return E.Errors(innerError, err)
default:
err = socks5.WriteResponse(conn, socks5.Response{
ReplyCode: socks5.ReplyCodeUnsupported,
})
if err != nil {
return err
}
return E.New("socks5: unsupported command ", request.Command)
}
}
return os.ErrInvalid
}