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280 | ------------------------------------------------------------------------------
-- Ada Web Server --
-- --
-- Copyright (C) 2012-2017, AdaCore --
-- --
-- This library is free software; you can redistribute it and/or modify --
-- it under terms of the GNU General Public License as published by the --
-- Free Software Foundation; either version 3, or (at your option) any --
-- later version. This library is distributed in the hope that it will be --
-- useful, but WITHOUT ANY WARRANTY; without even the implied warranty of --
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are --
-- granted additional permissions described in the GCC Runtime Library --
-- Exception, version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
------------------------------------------------------------------------------
with Ada.Strings.Maps.Constants;
with Ada.Text_IO;
with System;
with GNAT.Byte_Swapping;
with GNAT.MD5;
with AWS.Headers;
with AWS.Messages;
with AWS.Net.Buffered;
with AWS.Translator;
package body AWS.Net.WebSocket.Protocol.Draft76 is
use Ada.Text_IO;
-------------------------
-- Add_Connect_Headers --
-------------------------
overriding procedure Add_Connect_Headers
(Protocol : State;
URI : String;
Headers : in out AWS.Headers.List)
is
pragma Unreferenced (Protocol, URI, Headers);
begin
raise Program_Error
with "Connecting with draft76 protocol is not supported";
end Add_Connect_Headers;
--------------------
-- End_Of_Message --
--------------------
overriding function End_Of_Message (Protocol : State) return Boolean is
pragma Unreferenced (Protocol);
begin
return True;
end End_Of_Message;
-------------
-- Receive --
-------------
overriding procedure Receive
(Protocol : in out State;
Socket : Object;
Data : out Stream_Element_Array;
Last : out Stream_Element_Offset)
is
pragma Unreferenced (Protocol);
Byte : Stream_Element_Array (1 .. 1);
Ignored : Stream_Element_Offset;
begin
Ignored := 1;
Socket.Socket.Receive (Byte, Ignored);
if Byte (Byte'First) /= 0 then
Put_Line ("WebSocket 'received' did not receive a 0x00");
else
Last := Data'First;
loop
Ignored := 1;
Socket.Socket.Receive (Byte, Ignored);
exit when Byte (Byte'First) = 16#FF#;
Data (Last) := Byte (Byte'First);
Last := Last + 1;
end loop;
end if;
exception
when AWS.Net.Socket_Error =>
null;
when E : others =>
Put_Line ("Unexpected exception" & Exception_Information (E));
end Receive;
----------
-- Send --
----------
overriding procedure Send
(Protocol : in out State;
Socket : Object;
Data : Stream_Element_Array)
is
pragma Unreferenced (Protocol);
D_Header : constant Stream_Element_Array (1 .. 1) := (1 => 16#00#);
D_Footer : constant Stream_Element_Array (1 .. 1) := (1 => 16#FF#);
begin
Net.Buffered.Write (Socket, D_Header);
-- ??? Should encode in UTF-8 (to make sure there is no 16#FF# byte in
-- the message)
Net.Buffered.Write (Socket, Data);
Net.Buffered.Write (Socket, D_Footer);
Net.Buffered.Flush (Socket);
end Send;
overriding procedure Send
(Protocol : in out State;
Socket : Object;
Data : Unbounded_String) is
begin
Send
(Protocol, Socket,
Translator.To_Stream_Element_Array (To_String (Data)));
end Send;
-----------------
-- Send_Header --
-----------------
procedure Send_Header
(Sock : Net.Socket_Type'Class; Request : AWS.Status.Data)
is
use GNAT;
use System;
Headers : constant AWS.Headers.List := AWS.Status.Header (Request);
function WS_Key_Value (Key : String) return Interfaces.Unsigned_32;
-- Returns a WebSocket key as an Unsigned_32
------------------
-- WS_Key_Value --
------------------
function WS_Key_Value (Key : String) return Interfaces.Unsigned_32 is
use type Interfaces.Unsigned_32;
Spaces : Interfaces.Unsigned_32 := 0;
Value : Interfaces.Unsigned_32;
Result : Interfaces.Unsigned_32;
N : String (1 .. Key'Length);
I : Natural := 0;
begin
-- Get all digits
for K in Key'Range loop
if Strings.Maps.Is_In
(Key (K), Strings.Maps.Constants.Decimal_Digit_Set)
then
I := I + 1;
N (I) := Key (K);
elsif Key (K) = ' ' then
Spaces := Spaces + 1;
end if;
end loop;
Value := Interfaces.Unsigned_32'Value (N (N'First .. I));
-- ??? Should check that Spaces /= 0
-- ??? Should check that Value is an integral multiple of Spaces
Result := Value / Spaces;
return Result;
end WS_Key_Value;
-- Key 1
K1 : constant String :=
Headers.Get_Values (Messages.Sec_WebSocket_Key1_Token);
V1 : constant Interfaces.Unsigned_32 := WS_Key_Value (K1);
B1 : Stream_Element_Array (1 .. 4);
for B1'Address use V1'Address;
pragma Import (Ada, B1); -- disable default initialization
-- Key 2
K2 : constant String :=
Headers.Get_Values (Messages.Sec_WebSocket_Key2_Token);
V2 : constant Interfaces.Unsigned_32 := WS_Key_Value (K2);
B2 : Stream_Element_Array (1 .. 4);
for B2'Address use V2'Address;
pragma Import (Ada, B2); -- disable default initialization
-- Body
B : constant Stream_Element_Array :=
AWS.Status.Binary_Data (Request);
C : MD5.Context;
D : MD5.Message_Digest;
S : Stream_Element_Array (1 .. D'Length);
for S'Address use D'Address;
pragma Import (Ada, S); -- disable default initialization
begin
if B'Length /= 8 then
Put_Line ("Error, could not read binary_data from request");
end if;
-- Send protocol-specific headers
Net.Buffered.Put_Line
(Sock,
AWS.Messages.Sec_WebSocket_Location_Token
& ": ws://"
& AWS.Status.Host (Request)
& AWS.Status.URI (Request));
Net.Buffered.Put_Line
(Sock,
AWS.Messages.Sec_WebSocket_Origin_Token
& ": " & AWS.Status.Origin (Request));
-- End of header
Net.Buffered.New_Line (Sock);
-- Send body of the handshake (ie answer the challenge)
-- This is only steps "4." and later of the draft protocol, the rest of
-- the handshake has already been conducted.
if Default_Bit_Order = Low_Order_First then
Byte_Swapping.Swap4 (B1'Address);
Byte_Swapping.Swap4 (B2'Address);
end if;
-- Compute MD5 of B1 & B2 & B
MD5.Update (C, B1);
MD5.Update (C, B2);
MD5.Update (C, B);
D := MD5.Digest (C);
-- The following output is the body for the response
declare
V : Natural;
S : Natural;
begin
for K in 1 .. D'Length / 2 loop
S := K * 2 - 1;
V := Natural'Value ("16#" & D (S .. S + 1) & "#");
Net.Buffered.Put (Sock, String'(1 => Character'Val (V)));
end loop;
end;
Net.Buffered.Flush (Sock);
end Send_Header;
end AWS.Net.WebSocket.Protocol.Draft76;
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