------------------------------------------------------------------------------
--                              Ada Web Server                              --
--                                                                          --
--                     Copyright (C) 2006-2009, AdaCore                     --
--                                                                          --
--  This library is free software; you can redistribute it and/or modify    --
--  it under the terms of the GNU General Public License as published by    --
--  the Free Software Foundation; either version 2 of the License, 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.  See the GNU       --
--  General Public License for more details.                                --
--                                                                          --
--  You should have received a copy of the GNU General Public License       --
--  along with this library; if not, write to the Free Software Foundation, --
--  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.          --
--                                                                          --
--  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 AWS.Net.Log;

with Interfaces.C.Strings;
with System;

package body AWS.Net.SSL.Certificate is

   use Interfaces;

   procedure Check_Error_Code (Code : C.int; Socket : Socket_Type'Class);

   ----------------------
   -- Check_Error_Code --
   ----------------------

   procedure Check_Error_Code
     (Code : C.int; Socket : Socket_Type'Class)
   is
      use type C.int;
   begin
      if Code /= 0 then
         declare
            Error : constant String
              := C.Strings.Value (TSSL.gnutls_strerror (Code));
         begin
            Net.Log.Error (Socket, Error);
            Ada.Exceptions.Raise_Exception (Socket_Error'Identity, Error);
         end;
      end if;
   end Check_Error_Code;

   ---------
   -- Get --
   ---------

   function Get (Socket : Socket_Type) return Object is
      use type C.unsigned;
      use type System.Address;
      use type TSSL.a_gnutls_datum_t;

      Buffer_Size : constant := 256;
      --  Buffer size for the subject and issuer

      List_Size : aliased C.unsigned;
      Datum : constant TSSL.a_gnutls_datum_t
        := TSSL.gnutls_certificate_get_peers (Socket.SSL, List_Size'Access);
      Cert  : aliased TSSL.gnutls_x509_crt_t;

      Subject  : aliased C.char_array := (1 .. Buffer_Size => C.nul);
      Subj_Len : aliased C.size_t := Buffer_Size;
      Issuer   : aliased C.char_array := (1 .. Buffer_Size => C.nul);
      Iss_Len  : aliased C.size_t := Buffer_Size;
   begin
      if List_Size = 0 or else Datum = null then
         return Undefined;
      end if;

      Check_Error_Code (TSSL.gnutls_x509_crt_init (Cert'Access), Socket);
      Check_Error_Code
        (TSSL.gnutls_x509_crt_import
           (Cert, Datum.all, TSSL.GNUTLS_X509_FMT_DER),
         Socket);

      Check_Error_Code
        (TSSL.gnutls_x509_crt_get_dn
           (Cert,
            C.Strings.To_Chars_Ptr (Subject'Unchecked_Access),
            Subj_Len'Access),
         Socket);

      Check_Error_Code
        (TSSL.gnutls_x509_crt_get_issuer_dn
           (Cert,
            C.Strings.To_Chars_Ptr (Issuer'Unchecked_Access),
            Iss_Len'Access),
         Socket);

      TSSL.gnutls_x509_crt_deinit (Cert);

      return (Subject => To_Unbounded_String
                           (C.To_Ada (Subject (1 .. Subj_Len), False)),
             Issuer   => To_Unbounded_String
                           (C.To_Ada (Issuer (1 .. Iss_Len), False)));
   end Get;

   ------------
   -- Issuer --
   ------------

   function Issuer (Certificate : Object) return String is
   begin
      return To_String (Certificate.Issuer);
   end Issuer;

   -------------
   -- Subject --
   -------------

   function Subject (Certificate : Object) return String is
   begin
      return To_String (Certificate.Subject);
   end Subject;

end AWS.Net.SSL.Certificate;
