pascal/lazarus-dcpcrypt
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Added two new utility methods. ZeroMemory() and XorBlockEx()

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This commit is contained in:
Graeme Geldenhuys
2010-03-26 12:20:36 +02:00
parent a1e559bf57
commit 1bc3ce7147
1 changed files with 34 additions and 1 deletions
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35
dcpcrypt2.pas
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@@ -247,9 +247,12 @@ type
{ Helper functions }
procedure XorBlock(var InData1, InData2; Size: longword);
// Supposed to be an optimized version of XorBlock() using 32-bit xor
procedure XorBlockEx(var InData1, InData2; Size: longword);
// removes the compiler hint due to first param being 'var' instead of 'out'
procedure dcpFillChar(out x; count: SizeInt; Value: Byte); overload;
procedure dcpFillChar(out x; count: SizeInt; Value: Char); overload;
procedure ZeroMemory(Destination: Pointer; Length: PtrUInt);
@@ -658,6 +661,11 @@ begin
{$HINTS ON}
end;
procedure ZeroMemory(Destination: Pointer; Length: PtrUInt);
begin
FillChar(Destination^, Length, 0);
end;
procedure dcpFillChar(out x; count: SizeInt; Value: Char);
begin
{$HINTS OFF}
@@ -665,5 +673,30 @@ begin
{$HINTS ON}
end;
end.
// Supposed to be an optimized version of XorBlock() using 32-bit xor
procedure XorBlockEx(var InData1, InData2; Size: longword);
var
l1: PIntegerArray;
l2: PIntegerArray;
b1: PByteArray;
b2: PByteArray;
i: integer;
c: integer;
begin
l1 := @inData1;
l2 := @inData2;
for i := 0 to size div sizeof(LongWord)-1 do
l1[i] := l1[i] xor l2[i];
// the rest of the buffer (3 bytes)
c := size mod sizeof(longWord);
if c > 0 then begin
b1 := @InData1;
b2 := @InData2;
for i := (size-c) to size-1 do
b1[i] := b1[i] xor b2[i];
end;
end;
end.