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------------------------------------------------------------------------------
-- Secure Sockets Layer --
-- --
-- Copyright (C) 2005-2012, 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.Numerics.Discrete_Random;
with Ada.Unchecked_Conversion;
with Interfaces.C.Strings;
with System;
with SSL.Thin;
package body SSL.Ada_Random is
use type System.Address;
package C renames Interfaces.C;
package CS renames C.Strings;
type Byte_Type is mod 256;
pragma Convention (C, Byte_Type);
type Byte_Array is array (Positive range <>) of Byte_Type;
pragma Pack (Byte_Array);
pragma Convention (C, Byte_Array);
subtype C_Byte_Array is Byte_Array (Positive'Range);
type Unsigned is mod 2**System.Word_Size;
subtype Bytes_4 is Byte_Array (1 .. Unsigned'Size / System.Storage_Unit);
package Unsigned_Random is new Ada.Numerics.Discrete_Random (Unsigned);
protected Generator is
procedure Reset (Initiator : in Integer);
procedure Random (Result : out Unsigned);
-- Use protected procedure to get random number, because
-- function Ada.Numerics.Discrete_Random.Random is modifying state of the
-- random numbers generator.
function Is_Initialized return Boolean;
private
Gen : Unsigned_Random.Generator;
Initialized : Boolean := False;
end Generator;
function To_Integer is new Ada.Unchecked_Conversion (Unsigned, Integer);
function To_Unsigned is new Ada.Unchecked_Conversion (Integer, Unsigned);
function To_Bytes_4 is new Ada.Unchecked_Conversion (Unsigned, Bytes_4);
function To_Unsigned is new Ada.Unchecked_Conversion (Bytes_4, Unsigned);
function Random return Unsigned;
pragma Inline (Random);
procedure Seed (Buf : in C_Byte_Array; Num : Integer);
pragma Convention (C, Seed);
function Bytes (Buf : access C_Byte_Array; Num : Integer) return Integer;
pragma Convention (C, Bytes);
procedure Cleanup;
pragma Convention (C, Cleanup);
procedure Add (Buf : in C_Byte_Array; Num : Integer; Entropy : Integer);
pragma Convention (C, Add);
function Status return Integer;
pragma Convention (C, Status);
Method : aliased Thin.Rand_Meth_St
:= (Seed => Seed'Address,
Bytes => Bytes'Address,
Cleanup => Cleanup'Address,
Add => Add'Address,
Pseudorand => Bytes'Address,
Status => Status'Address);
function To_Initiator (Buf : in Byte_Array) return Integer;
---------
-- Add --
---------
procedure Add (Buf : in C_Byte_Array; Num : Integer; Entropy : Integer) is
begin
Generator.Reset (To_Initiator (To_Bytes_4 (Random) & Buf (1 .. Num)));
end Add;
-----------
-- Bytes --
-----------
function Bytes (Buf : access C_Byte_Array; Num : Integer) return Integer is
B4 : Bytes_4;
Index : Positive := B4'Last + 1;
function Get_Next return Byte_Type;
--------------
-- Get_Next --
--------------
function Get_Next return Byte_Type is
begin
Index := Index + 1;
if Index > B4'Last then
Index := B4'First;
B4 := To_Bytes_4 (Random);
end if;
return B4 (Index);
end Get_Next;
begin
for J in 1 .. Num loop
Buf (J) := Get_Next;
end loop;
return 1;
end Bytes;
-------------
-- Cleanup --
-------------
procedure Cleanup is
begin
Generator.Reset (0);
end Cleanup;
---------------
-- Generator --
---------------
protected body Generator is
--------------------
-- Is_Initialized --
--------------------
function Is_Initialized return Boolean is
begin
return Initialized;
end Is_Initialized;
------------
-- Random --
------------
procedure Random (Result : out Unsigned) is
begin
Result := Unsigned_Random.Random (Gen);
end Random;
-----------
-- Reset --
-----------
procedure Reset (Initiator : in Integer) is
begin
Unsigned_Random.Reset (Gen, Initiator);
Initialized := True;
end Reset;
end Generator;
------------
-- Random --
------------
function Random return Unsigned is
Result : Unsigned;
begin
Generator.Random (Result);
return Result;
end Random;
----------------
-- Initialize --
----------------
procedure Initialize is
begin
Thin.RAND_set_rand_method (Method'Access);
end Initialize;
----------
-- Seed --
----------
procedure Seed (Buf : in C_Byte_Array; Num : Integer) is
begin
Generator.Reset (To_Initiator (Buf (1 .. Num)));
end Seed;
------------
-- Status --
------------
function Status return Integer is
begin
return Boolean'Pos (Generator.Is_Initialized);
end Status;
function To_Initiator (Buf : in Byte_Array) return Integer is
Init : Unsigned := 0;
begin
for J in Buf'Range loop
declare
function Next_Unsigned return Unsigned;
pragma Inline (Next_Unsigned);
-------------------
-- Next_Unsigned --
-------------------
function Next_Unsigned return Unsigned is
begin
case Buf'Last - J is
when 0 =>
return To_Unsigned ((Buf (J), Buf (Buf'First), 0, 0));
when 1 =>
return To_Unsigned
((Buf (J), Buf (J + 1), Buf (Buf'First), 0));
when 2 =>
return To_Unsigned
((Buf (J),
Buf (J + 1),
Buf (J + 2),
Buf (Buf'First)));
when others =>
return To_Unsigned (Buf (J .. J + 3));
end case;
end Next_Unsigned;
begin
Init := Init xor Next_Unsigned;
end;
end loop;
return To_Integer (Init);
end To_Initiator;
end SSL.Ada_Random;
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