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 function HogeBase64Encode(inputArray: array of Byte): string; overload;
  16
  17 implementation
  18
  19 const
  20   Enc64Tbl: array[0..63] of Char =
  21              ('A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
  22               'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
  23               'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
  24               'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/');
  25
  26   (* \83f\83R\81[\83h\83e\81[\83u\83\8b \83\81\83\93\83h\83C *)
  27
  28 procedure HogeBase64Encode(inputStream, outputStream: TStream);
  29 var
  30   inBuf: array [0..2] of byte;
  31   outBuf: array[0..3] of Char;
  32   size: integer;
  33 begin
  34   repeat
  35     size := inputStream.Read(inBuf, sizeof(inBuf));
  36     case size of
  37     0: break;
  38     1:
  39       begin
  40         outBuf[0] := Enc64Tbl[inBuf[0] shr 2];
  41         outBuf[1] := Enc64Tbl[(inBuf[0] shl 4) and $3F];
  42         outBuf[2] := '=';
  43         outBuf[3] := '=';
  44       end;
  45     2:
  46       begin
  47         outBuf[0] := Enc64Tbl[inBuf[0] shr 2];
  48         outBuf[1] := Enc64Tbl[((inBuf[0] shl 4) or (inBuf[1] shr 4)) and $3F];
  49         outBuf[2] := Enc64Tbl[((inBuf[1] shl 2)                     ) and $3F];
  50         outBuf[3] := '=';
  51       end;
  52     3:
  53       begin
  54         outBuf[0] := Enc64Tbl[inBuf[0] shr 2];
  55         outBuf[1] := Enc64Tbl[((inBuf[0] shl 4) or (inBuf[1] shr 4)) and $3F];
  56         outBuf[2] := Enc64Tbl[((inBuf[1] shl 2) or (inBuf[2] shr 6)) and $3F];
  57         outBuf[3] := Enc64Tbl[inBuf[2] and $3F];
  58       end;
  59     end;
  60     outputStream.WriteBuffer(outBuf, sizeof(outBuf));
  61   until size < sizeof(inBuf);
  62 end;
  63
  64 procedure HogeBase64Decode(inputStream, outputStream: TStream);
  65 var
  66   inBuf: array [0..3] of Char;
  67   outBuf: array[0..2] of byte;
  68   code: byte;
  69   size: integer;
  70   i, endPos: integer;
  71 begin
  72   code := 0;
  73   repeat
  74     size := inputStream.Read(inBuf, sizeof(inBuf));
  75     if size = 0 then
  76       break;
  77     if size <> 4 then
  78       raise EConvertError.Create('unexpected size');
  79     for i := 0 to sizeof(outBuf) -1 do
  80       outBuf[i] := 0;
  81     endPos := -1;
  82     for i := 0 to sizeof(inBuf) - 1 do
  83     begin
  84       case inBuf[i] of
  85       'A'..'Z': code := Ord(inBuf[i]) - Ord('A');
  86       'a'..'z': code := Ord(inBuf[i]) - Ord('a') + 26;
  87       '0'..'9': code := Ord(inBuf[i]) - Ord('0') + 26 + 26;
  88       '+':      code := 62;
  89       '/':      code := 63;
  90       '=':
  91         begin
  92           if i = 0 then
  93             raise EConvertError.Create('unexpected "="');
  94           endPos := i -1;
  95           break;
  96         end;
  97       else
  98         raise EConvertError.Create(Format('unexpected code($%2.2X)', [Ord(inBuf[i])]));
  99       end;
 100       case i of
 101       0:
 102         begin
 103           outBuf[0] := code shl 2;
 104         end;
 105       1:
 106         begin
 107           outBuf[0] := outBuf[0] or (code shr 4);
 108           outBuf[1] := byte( code shl 4 );
 109         end;
 110       2:
 111         begin
 112           outBuf[1] := outBuf[1] or (code shr 2);
 113           outBuf[2] := byte( code shl 6 );
 114         end;
 115       3:
 116         begin
 117           outBuf[2] := outBuf[2] or code;
 118         end;
 119       end;
 120     end;
 121     if endPos < 0 then
 122       endPos := sizeof(outBuf);
 123     outputStream.WriteBuffer(outBuf, endPos);
 124   until size < sizeof(inBuf);
 125 end;
 126
 127
 128 function HogeBase64Encode(const inputStr: string): string; overload;
 129 var
 130   inputStream, outputStream: TStringStream;
 131 begin
 132   inputStream := TStringStream.Create(inputStr);
 133   outputStream:= TStringStream.Create('');
 134   HogeBase64Encode(inputStream, outputStream);
 135   result := outputStream.DataString;
 136   outputStream.Free;
 137   inputStream.Free;
 138 end;
 139
 140 function HogeBase64Decode(const inputStr: string): string; overload;
 141 var
 142   inputStream, outputStream: TStringStream;
 143 begin
 144   inputStream := TStringStream.Create(inputStr);
 145   outputStream:= TStringStream.Create('');
 146   HogeBase64Decode(inputStream, outputStream);
 147   result := outputStream.DataString;
 148   outputStream.Free;
 149   inputStream.Free;
 150 end;
 151
 152 function HogeBase64Encode(inputArray: array of Byte): string; overload;
 153 var
 154   inputStream: TMemoryStream;
 155   outputStream: TStringStream;
 156 begin
 157   inputStream := TMemoryStream.Create;
 158   inputStream.WriteBuffer(inputArray, Length(inputArray));
 159   inputStream.Position := 0;
 160   outputStream:= TStringStream.Create('');
 161   HogeBase64Encode(inputStream, outputStream);
 162   result := outputStream.DataString;
 163   outputStream.Free;
 164   inputStream.Free;
 165 end;
 166
 167 end.