Encrypt/UBase64.pas

   1 unit UBase64;
   2 (* 2002 Twiddle *)
   3 (* \82©\82È\82è\83C\83\93\83`\83L\81\95\8cø\97¦\88«\82¢\81\95\90^\96Ê\96Ú\82É\8c\9f\8fØ\82µ\82Ä\82È\82¢ *)
   4
   5 interface
   6 uses
   7   Classes,
   8   SysUtils;
   9
  10 procedure HogeBase64Encode(inputStream, outputStream: TStream); overload;
  11 procedure HogeBase64Decode(inputStream, outputStream: TStream); overload;
  12
  13 function HogeBase64Encode(const inputStr: string): string; overload;
  14 function HogeBase64Decode(const inputStr: string): string; overload;
  15
  16 implementation
  17
  18 const
  19   Enc64Tbl: array[0..63] of Char =
  20              ('A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
  21               'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
  22               'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
  23               'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/');
  24
  25   (* \83f\83R\81[\83h\83e\81[\83u\83\8b \83\81\83\93\83h\83C *)
  26
  27 procedure HogeBase64Encode(inputStream, outputStream: TStream);
  28 var
  29   inBuf: array [0..2] of byte;
  30   outBuf: array[0..3] of Char;
  31   size: integer;
  32 begin
  33   repeat
  34     size := inputStream.Read(inBuf, sizeof(inBuf));
  35     case size of
  36     0: break;
  37     1:
  38       begin
  39         outBuf[0] := Enc64Tbl[inBuf[0] shr 2];
  40         outBuf[1] := Enc64Tbl[(inBuf[0] shl 4) and $3F];
  41         outBuf[2] := '=';
  42         outBuf[3] := '=';
  43       end;
  44     2:
  45       begin
  46         outBuf[0] := Enc64Tbl[inBuf[0] shr 2];
  47         outBuf[1] := Enc64Tbl[((inBuf[0] shl 4) or (inBuf[1] shr 4)) and $3F];
  48         outBuf[2] := Enc64Tbl[((inBuf[1] shl 2)                     ) and $3F];
  49         outBuf[3] := '=';
  50       end;
  51     3:
  52       begin
  53         outBuf[0] := Enc64Tbl[inBuf[0] shr 2];
  54         outBuf[1] := Enc64Tbl[((inBuf[0] shl 4) or (inBuf[1] shr 4)) and $3F];
  55         outBuf[2] := Enc64Tbl[((inBuf[1] shl 2) or (inBuf[2] shr 6)) and $3F];
  56         outBuf[3] := Enc64Tbl[inBuf[2] and $3F];
  57       end;
  58     end;
  59     outputStream.WriteBuffer(outBuf, sizeof(outBuf));
  60   until size < sizeof(inBuf);
  61 end;
  62
  63 procedure HogeBase64Decode(inputStream, outputStream: TStream);
  64 var
  65   inBuf: array [0..3] of Char;
  66   outBuf: array[0..2] of byte;
  67   code: byte;
  68   size: integer;
  69   i, endPos: integer;
  70 begin
  71   code := 0;
  72   repeat
  73     size := inputStream.Read(inBuf, sizeof(inBuf));
  74     if size = 0 then
  75       break;
  76     if size <> 4 then
  77       raise EConvertError.Create('unexpected size');
  78     for i := 0 to sizeof(outBuf) -1 do
  79       outBuf[i] := 0;
  80     endPos := -1;
  81     for i := 0 to sizeof(inBuf) - 1 do
  82     begin
  83       case inBuf[i] of
  84       'A'..'Z': code := Ord(inBuf[i]) - Ord('A');
  85       'a'..'z': code := Ord(inBuf[i]) - Ord('a') + 26;
  86       '0'..'9': code := Ord(inBuf[i]) - Ord('0') + 26 + 26;
  87       '+':      code := 62;
  88       '/':      code := 63;
  89       '=':
  90         begin
  91           if i = 0 then
  92             raise EConvertError.Create('unexpected "="');
  93           endPos := i -1;
  94           break;
  95         end;
  96       else
  97         raise EConvertError.Create(Format('unexpected code($%2.2X)', [Ord(inBuf[i])]));
  98       end;
  99       case i of
 100       0:
 101         begin
 102           outBuf[0] := code shl 2;
 103         end;
 104       1:
 105         begin
 106           outBuf[0] := outBuf[0] or (code shr 4);
 107           outBuf[1] := byte( code shl 4 );
 108         end;
 109       2:
 110         begin
 111           outBuf[1] := outBuf[1] or (code shr 2);
 112           outBuf[2] := byte( code shl 6 );
 113         end;
 114       3:
 115         begin
 116           outBuf[2] := outBuf[2] or code;
 117         end;
 118       end;
 119     end;
 120     if endPos < 0 then
 121       endPos := sizeof(outBuf);
 122     outputStream.WriteBuffer(outBuf, endPos);
 123   until size < sizeof(inBuf);
 124 end;
 125
 126
 127 function HogeBase64Encode(const inputStr: string): string; overload;
 128 var
 129   inputStream, outputStream: TStringStream;
 130 begin
 131   inputStream := TStringStream.Create(inputStr);
 132   outputStream:= TStringStream.Create('');
 133   HogeBase64Encode(inputStream, outputStream);
 134   result := outputStream.DataString;
 135   outputStream.Free;
 136   inputStream.Free;
 137 end;
 138
 139 function HogeBase64Decode(const inputStr: string): string; overload;
 140 var
 141   inputStream, outputStream: TStringStream;
 142 begin
 143   inputStream := TStringStream.Create(inputStr);
 144   outputStream:= TStringStream.Create('');
 145   HogeBase64Decode(inputStream, outputStream);
 146   result := outputStream.DataString;
 147   outputStream.Free;
 148   inputStream.Free;
 149 end;
 150
 151 end.