Skip to content

Commit

Permalink
Making SendV4Response() and SendV5XXXResponse() be public methods of …
Browse files Browse the repository at this point in the history 
…TIdSocksServerContext (#540)

Resolves #512. Making SendV4Response() and SendV5XXXResponse() be public methods of TIdSocksServerContext
  • Loading branch information
@rlebeau
rlebeau authored Jul 24, 2024
1 parent 498cfcd commit c4e67ef
Showing 1 changed file with 94 additions and 83 deletions.
177 changes: 94 additions & 83 deletions Lib/Protocols/IdSocksServer.pas
View file
Original file line number Diff line number Diff line change
Expand Up @@ -110,6 +110,11 @@ interface
SysUtils;

const
IdSocks4ReplySuccess = 90;
IdSocks4ReplyFailed = 91;
IdSocks4ReplyNoIdent = 92;
IdSocks4ReplyIdentNotConfirmed = 93;

IdSocksAuthNoAuthenticationRequired = 0;
IdSocksAuthGSSApi = 1;
IdSocksAuthUsernamePassword = 2;
Expand Down Expand Up @@ -144,6 +149,13 @@ TIdSocksServerContext = class(TIdServerContext)
FSocksVersion: Byte; // either 4 or 5, or 0 when version not known yet
public
constructor Create(AConnection: TIdTCPConnection; AYarn: TIdYarn; AList: TIdContextThreadList = nil); override;
//
procedure SendV4Response(const AStatus: Byte; const AIP: String = ''; const APort: TIdPort = 0);
//
procedure SendV5MethodResponse(const AMethod: Byte);
procedure SendV5AuthResponse(const AStatus: Byte);
procedure SendV5Response(const AStatus: Byte; const AIP: String = ''; const APort: TIdPort = 0);
//
property IPVersion: TIdIPVersion read FIPVersion;
property Username: string read FUsername;
property Password: string read FPassword;
Expand Down Expand Up @@ -315,60 +327,6 @@ function TIdCustomSocksServer.DoVerifyBoundPeer(AContext: TIdSocksServerContext;
end;
end;


procedure SendV4Response(AContext: TIdSocksServerContext; const AStatus: Byte;
const AIP: String = ''; const APort: TIdPort = 0);
var
LResponse: TIdBytes;
begin
SetLength(LResponse, 8);
LResponse[0] := 0; // SOCKS version, null in SOCKS 4/4A
LResponse[1] := AStatus;
CopyTIdUInt16(GStack.HostToNetwork(APort), LResponse, 2);
CopyTIdBytes(IPToBytes(AIP, Id_IPv4), 0, LResponse, 4, 4);
AContext.Connection.IOHandler.Write(LResponse);
end;

procedure SendV5MethodResponse(AContext: TIdSocksServerContext; const AMethod: Byte);
var
LResponse: TIdBytes;
begin
SetLength(LResponse, 2);
LResponse[0] := 5; // SOCKS version
LResponse[1] := AMethod;
AContext.Connection.IOHandler.Write(LResponse);
end;

procedure SendV5AuthResponse(AContext: TIdSocksServerContext; const AStatus: Byte);
var
LResponse: TIdBytes;
begin
SetLength(LResponse, 2);
LResponse[0] := 1; // AUTH version
LResponse[1] := AStatus;
AContext.Connection.IOHandler.Write(LResponse);
end;

procedure SendV5Response(AContext: TIdSocksServerContext; const AStatus: Byte;
const AIP: String = ''; const APort: TIdPort = 0);
const
LTypes: array[TIdIPVersion] of Byte = ($1, $4);
var
LResponse, LIP: TIdBytes;
begin
LIP := IPToBytes(AIP, AContext.IPVersion);
SetLength(LResponse, 4 + Length(LIP) + 2);

LResponse[0] := 5; // SOCKS version
LResponse[1] := AStatus;
LResponse[2] := 0;
LResponse[3] := LTypes[AContext.IPVersion];
CopyTIdBytes(LIP, 0, LResponse, 4, Length(LIP));
CopyTIdUInt16(GStack.HostToNetwork(APort), LResponse, 4+Length(LIP));

AContext.Connection.IOHandler.Write(LResponse);
end;

procedure TIdCustomSocksServer.HandleConnectV4(AContext: TIdSocksServerContext;
var VCommand: Byte; var VHost: string; var VPort: TIdPort);
var
Expand Down Expand Up @@ -410,7 +368,7 @@ procedure TIdCustomSocksServer.HandleConnectV4(AContext: TIdSocksServerContext;
AContext.FUsername := LUserId;
AContext.FPassword := '';
if not DoAuthenticate(AContext) then begin
SendV4Response(AContext, 93);
AContext.SendV4Response(IdSocks4ReplyIdentNotConfirmed);
AContext.Connection.Disconnect;
raise EIdSocksSvrInvalidLogin.Create(RSSocksSvrInvalidLogin);
end;
Expand All @@ -430,23 +388,23 @@ procedure TIdCustomSocksServer.HandleConnectV5(AContext: TIdSocksServerContext;
if not NeedsAuthentication then begin
AContext.FUsername := '';
AContext.FPassword := '';
SendV5MethodResponse(AContext, IdSocksAuthNoAuthenticationRequired);
AContext.SendV5MethodResponse(IdSocksAuthNoAuthenticationRequired);
end else begin
if ByteIndex(IdSocksAuthUsernamePassword, LMethods) = -1 then begin
SendV5MethodResponse(AContext, IdSocksAuthNoAcceptableMethods);
AContext.SendV5MethodResponse(IdSocksAuthNoAcceptableMethods);
AContext.Connection.Disconnect; // not sure the server has to disconnect
raise EIdSocksSvrNotSupported.Create(RSSocksSvrNotSupported);
end;
SendV5MethodResponse(AContext, IdSocksAuthUsernamePassword);
AContext.SendV5MethodResponse(IdSocksAuthUsernamePassword);
AContext.Connection.IOHandler.ReadByte; //subversion, we don't need it.
AContext.FUsername := AContext.Connection.IOHandler.ReadString(AContext.Connection.IOHandler.ReadByte);
AContext.FPassword := AContext.Connection.IOHandler.ReadString(AContext.Connection.IOHandler.ReadByte);
if not DoAuthenticate(AContext) then begin
SendV5AuthResponse(AContext, IdSocks5ReplyGeneralFailure);
AContext.SendV5AuthResponse(IdSocks5ReplyGeneralFailure);
AContext.Connection.Disconnect;
raise EIdSocksSvrInvalidLogin.Create(RSSocksSvrInvalidLogin);
end;
SendV5AuthResponse(AContext, IdSocks5ReplySuccess);
AContext.SendV5AuthResponse(IdSocks5ReplySuccess);
end;

AContext.Connection.IOHandler.ReadByte; // socks version, should be 5
Expand Down Expand Up @@ -487,7 +445,7 @@ procedure TIdCustomSocksServer.HandleConnectV5(AContext: TIdSocksServerContext;
end;
else
begin
SendV5Response(AContext, IdSocks5ReplyAddrNotSupported);
AContext.SendV5Response(IdSocks5ReplyAddrNotSupported);
AContext.Connection.Disconnect;
raise EIdSocksSvrSocks5WrongATYP.Create(RSSocksSvrWrongATYP);
end;
Expand All @@ -513,8 +471,8 @@ function TIdCustomSocksServer.DoExecute(AContext: TIdContext): Boolean;
) then
begin
case LContext.SocksVersion of
4: SendV4Response(LContext, 91);
5: SendV5MethodResponse(LContext, IdSocksAuthNoAcceptableMethods);
4: LContext.SendV4Response(IdSocks4ReplyFailed);
5: LContext.SendV5MethodResponse(IdSocksAuthNoAcceptableMethods);
end;
AContext.Connection.Disconnect;
raise EIdSocksSvrWrongSocksVer.Create(RSSocksSvrWrongSocksVersion);
Expand All @@ -532,8 +490,8 @@ function TIdCustomSocksServer.DoExecute(AContext: TIdContext): Boolean;
else
begin
case LContext.SocksVersion of
4: SendV4Response(LContext, 91);
5: SendV5Response(LContext, IdSocks5ReplyCmdNotSupported);
4: LContext.SendV4Response(IdSocks4ReplyFailed);
5: LContext.SendV5Response(IdSocks5ReplyCmdNotSupported);
end;
AContext.Connection.Disconnect;
raise EIdSocksSvrWrongSocksCmd.Create(RSSocksSvrWrongSocksCommand);
Expand All @@ -553,8 +511,8 @@ procedure TIdSocksServer.CommandConnect(AContext: TIdSocksServerContext;

if not DoBeforeSocksConnect(AContext, LHost, LPort) then begin
case AContext.SocksVersion of
4: SendV4Response(AContext, 91);
5: SendV5Response(AContext, IdSocks5ReplyConnNotAllowed);
4: AContext.SendV4Response(IdSocks4ReplyFailed);
5: AContext.SendV5Response(IdSocks5ReplyConnNotAllowed);
end;
AContext.Connection.Disconnect;
raise EIdSocksSvrAccessDenied.Create(RSSocksSvrAccessDenied);
Expand All @@ -575,16 +533,16 @@ procedure TIdSocksServer.CommandConnect(AContext: TIdSocksServerContext;
// TODO: for v5, check the socket error and send an appropriate reply
// (Network unreachable, Host unreachable, Connection refused, etc)...
case AContext.SocksVersion of
4: SendV4Response(AContext, 91);
5: SendV5Response(AContext, IdSocks5ReplyHostUnreachable);
4: AContext.SendV4Response(IdSocks4ReplyFailed);
5: AContext.SendV5Response(IdSocks5ReplyHostUnreachable);
end;
AContext.Connection.Disconnect;
raise;
end;

case AContext.SocksVersion of
4: SendV4Response(AContext, 90, LClient.Socket.Binding.IP, LClient.Socket.Binding.Port);
5: SendV5Response(AContext, IdSocks5ReplySuccess, LClient.Socket.Binding.IP, LClient.Socket.Binding.Port);
4: AContext.SendV4Response(IdSocks4ReplySuccess, LClient.Socket.Binding.IP, LClient.Socket.Binding.Port);
5: AContext.SendV5Response(IdSocks5ReplySuccess, LClient.Socket.Binding.IP, LClient.Socket.Binding.Port);
end;

TransferData(AContext.Connection, LClient);
Expand All @@ -607,8 +565,8 @@ procedure TIdSocksServer.CommandBind(AContext: TIdSocksServerContext;

if not DoBeforeSocksBind(AContext, LHost, LPort) then begin
case AContext.SocksVersion of
4: SendV4Response(AContext, 91);
5: SendV5Response(AContext, IdSocks5ReplyConnNotAllowed);
4: AContext.SendV4Response(IdSocks4ReplyFailed);
5: AContext.SendV5Response(IdSocks5ReplyConnNotAllowed);
end;
AContext.Connection.Disconnect;
raise EIdSocksSvrAccessDenied.Create(RSSocksSvrAccessDenied);
Expand All @@ -622,24 +580,24 @@ procedure TIdSocksServer.CommandBind(AContext: TIdSocksServerContext;
LServer.BeginListen;
except
case AContext.SocksVersion of
4: SendV4Response(AContext, 91);
5: SendV5Response(AContext, IdSocks5ReplyGeneralFailure);
4: AContext.SendV4Response(IdSocks4ReplyFailed);
5: AContext.SendV5Response(IdSocks5ReplyGeneralFailure);
end;
AContext.Connection.Disconnect;
raise;
end;

case AContext.SocksVersion of
4: SendV4Response(AContext, 90, LServer.Binding.IP, LServer.Binding.Port);
5: SendV5Response(AContext, IdSocks5ReplySuccess, LServer.Binding.IP, LServer.Binding.Port);
4: AContext.SendV4Response(IdSocks4ReplySuccess, LServer.Binding.IP, LServer.Binding.Port);
5: AContext.SendV5Response(IdSocks5ReplySuccess, LServer.Binding.IP, LServer.Binding.Port);
end;

try
LServer.Listen(120000); // 2 minutes
except
case AContext.SocksVersion of
4: SendV4Response(AContext, 91);
5: SendV5Response(AContext, IdSocks5ReplyGeneralFailure);
4: AContext.SendV4Response(IdSocks4ReplyFailed);
5: AContext.SendV5Response(IdSocks5ReplyGeneralFailure);
end;
AContext.Connection.Disconnect;
raise;
Expand All @@ -649,16 +607,16 @@ procedure TIdSocksServer.CommandBind(AContext: TIdSocksServerContext;
if not DoVerifyBoundPeer(AContext, LHost, LServer.Binding.PeerIP) then begin
LServer.Disconnect;
case AContext.SocksVersion of
4: SendV4Response(AContext, 91);
5: SendV5Response(AContext, IdSocks5ReplyGeneralFailure);
4: AContext.SendV4Response(IdSocks4ReplyFailed);
5: AContext.SendV5Response(IdSocks5ReplyGeneralFailure);
end;
AContext.Connection.Disconnect;
raise EIdSocksSvrPeerMismatch.Create(RSSocksSvrPeerMismatch);
end;

case AContext.SocksVersion of
4: SendV4Response(AContext, 90, LServer.Binding.PeerIP, LServer.Binding.PeerPort);
5: SendV5Response(AContext, IdSocks5ReplySuccess, LServer.Binding.PeerIP, LServer.Binding.PeerPort);
4: AContext.SendV4Response(IdSocks4ReplySuccess, LServer.Binding.PeerIP, LServer.Binding.PeerPort);
5: AContext.SendV5Response(IdSocks5ReplySuccess, LServer.Binding.PeerIP, LServer.Binding.PeerPort);
end;

TransferData(AContext.Connection, LServer);
Expand Down Expand Up @@ -708,5 +666,58 @@ constructor TIdSocksServerContext.Create(AConnection: TIdTCPConnection; AYarn: T
FSocksVersion := 0;
end;

procedure TIdSocksServerContext.SendV4Response(const AStatus: Byte;
const AIP: String = ''; const APort: TIdPort = 0);
var
LResponse: TIdBytes;
begin
SetLength(LResponse, 8);
LResponse[0] := 0; // SOCKS version, null in SOCKS 4/4A
LResponse[1] := AStatus;
CopyTIdUInt16(GStack.HostToNetwork(APort), LResponse, 2);
CopyTIdBytes(IPToBytes(AIP, Id_IPv4), 0, LResponse, 4, 4);
Connection.IOHandler.Write(LResponse);
end;

procedure TIdSocksServerContext.SendV5MethodResponse(const AMethod: Byte);
var
LResponse: TIdBytes;
begin
SetLength(LResponse, 2);
LResponse[0] := 5; // SOCKS version
LResponse[1] := AMethod;
Connection.IOHandler.Write(LResponse);
end;

procedure TIdSocksServerContext.SendV5AuthResponse(const AStatus: Byte);
var
LResponse: TIdBytes;
begin
SetLength(LResponse, 2);
LResponse[0] := 1; // AUTH version
LResponse[1] := AStatus;
Connection.IOHandler.Write(LResponse);
end;

procedure TIdSocksServerContext.SendV5Response(const AStatus: Byte;
const AIP: String = ''; const APort: TIdPort = 0);
const
LTypes: array[TIdIPVersion] of Byte = ($1, $4);
var
LResponse, LIP: TIdBytes;
begin
LIP := IPToBytes(AIP, IPVersion);
SetLength(LResponse, 4 + Length(LIP) + 2);

LResponse[0] := 5; // SOCKS version
LResponse[1] := AStatus;
LResponse[2] := 0;
LResponse[3] := LTypes[IPVersion];
CopyTIdBytes(LIP, 0, LResponse, 4, Length(LIP));
CopyTIdUInt16(GStack.HostToNetwork(APort), LResponse, 4+Length(LIP));

Connection.IOHandler.Write(LResponse);
end;

end.

0 comments on commit c4e67ef

Please sign in to comment.