doublecmd/src/platform/urandom.pas
2017-08-19 22:28:14 +00:00

121 lines
3.2 KiB
ObjectPascal

{
Double Commander
-------------------------------------------------------------------------
Cryptographically secure pseudo-random number generator
Copyright (C) 2017 Alexander Koblov (alexx2000@mail.ru)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser 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
}
unit uRandom;
{$mode delphi}
interface
procedure Random(ABlock: PByte; ACount: Integer);
implementation
uses
ISAAC
{$IF DEFINED(MSWINDOWS)}
, Windows
{$ELSEIF DEFINED(UNIX)}
, DCOSUtils
{$IF DEFINED(LINUX)}
, dl, BaseUnix, InitC
{$ENDIF}
{$ENDIF}
, SysUtils
{$IF (FPC_FULLVERSION < 30000)}
, LazUTF8SysUtils
{$ENDIF}
;
threadvar
Context: isaac_ctx;
{$IF DEFINED(MSWINDOWS)}
var
RtlGenRandom: function(RandomBuffer: PByte; RandomBufferLength: ULONG): LongBool; stdcall;
{$ELSEIF DEFINED(UNIX)}
const
random_dev = '/dev/urandom';
var
HasRandom: Boolean = False;
{$IF DEFINED(LINUX)}
getrandom: function(buf: PByte; buflen: csize_t; flags: cuint): cint; cdecl;
{$ENDIF}
{$ENDIF}
procedure Random(ABlock: PByte; ACount: Integer);
var
{$IF DEFINED(UNIX)}
Handle: THandle;
{$ENDIF}
Result: Boolean = False;
begin
{$IF DEFINED(MSWINDOWS)}
Result:= Assigned(RtlGenRandom);
if Result then Result:= RtlGenRandom(ABlock, ACount);
{$ELSEIF DEFINED(UNIX)} {$IF DEFINED(LINUX)}
if Assigned(getrandom) then
begin
repeat
Result:= (getrandom(ABlock, ACount, 0) = ACount);
until (Result = True) or (fpgetCerrno <> ESysEINTR);
end;
if not Result then
{$ENDIF}
if HasRandom then
begin
Handle:= mbFileOpen(random_dev, fmOpenRead or fmShareDenyNone);
Result:= (Handle <> feInvalidHandle);
if Result then
begin
Result:= (FileRead(Handle, ABlock^, ACount) = ACount);
FileClose(Handle);
end;
end;
{$ENDIF}
if not Result then
begin
if (Context.randidx = 0) then
begin
isaac_inita({%H-}Context, [Int32(GetTickCount64),
Integer(GetThreadID),
Integer(GetProcessID),
GetHeapStatus.TotalFree,
Int32(Trunc(Now * MSecsPerDay))], 5);
end;
isaac_read(Context, ABlock, ACount);
end;
end;
initialization
{$IF DEFINED(MSWINDOWS)}
@RtlGenRandom:= GetProcAddress(GetModuleHandle('advapi32.dll'), 'SystemFunction036');
{$ELSEIF DEFINED(UNIX)}
HasRandom:= mbFileAccess(random_dev, fmOpenRead);
{$IF DEFINED(LINUX)}
@getrandom:= dlsym(dlopen('libc.so.6', RTLD_NOW), 'getrandom');
{$ENDIF}
{$ENDIF}
end.