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Y64 Help needed Porting.

Posted on 2009-06-26
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Last Modified: 2012-05-07
I'm trying to port a Y64/Yahoo64 routine to Delphi problem is I'm having difficulty understanding the code I'm porting, I have several sources of this Y64 but none in Pascal/Delphi.

It's apparently similar to Mac64 which produces a similar string but it's 2 bytes longer.

If i can work out

                  $dest.=$yahoo64[ord($source[$in])>>2];                   
            $dest.=$yahoo64[((ord($source[$in])<<4)&0x30) | (ord($source[$in+1])>>4)];
            $dest.=$yahoo64[((ord($source[$in+1])<<2)&0x3C) | (ord($source[$in+2])>>6)];
            $dest.=$yahoo64[ord($source[$in+2])&0x3F];
            $in += 3;

How to covert that to Pascal I can finish the rest myself . or if anyone knows where y64 exists already in pascal save me a huge headache.

Thanks..
function y64($source)
{  $yahoo64="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789._"; 
	// something with 16 bytes not hex
	$inlen = 16;
	$in=0;
	// in este ce primim
	for(; $inlen >=3; $inlen -=3)
	{
			$dest.=$yahoo64[ord($source[$in])>>2]; 			
		$dest.=$yahoo64[((ord($source[$in])<<4)&0x30) | (ord($source[$in+1])>>4)]; 
		$dest.=$yahoo64[((ord($source[$in+1])<<2)&0x3C) | (ord($source[$in+2])>>6)]; 
		$dest.=$yahoo64[ord($source[$in+2])&0x3F]; 
		$in += 3;
	}	
	if($inlen>0)
	{
		// enters here :)
		$dest.=$yahoo64[ord($source[$in])>>2]; 
		$fragment = ((ord($source[$in])<<4)&0x30);
		if($inlen>1){$fragment |= (ord($source[$in+1])>>4);			}
		$dest.=$yahoo64[$fragment];
		if($inlen<2)
			{$dest.="-";}
		else
			{$dest.=$yahoo64[((ord($source[$in+1])<<2)&0x3c)]; }
		$dest.="-";
		
	}	
        
	
	return $dest;
}
 
or this routine...
 
function y64($source)
{ $yahoo64="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789._";
// something with 16 bytes not hex
$inlen = 16;
$in=0;
// in este ce primim
for(; $inlen >=3; $inlen -=3)
{
$dest.=$yahoo64[ord($source[$in])>>2];
$dest.=$yahoo64[((ord($source[$in])<<4)&0x30) | (ord($source[$in+1])>>4)];
$dest.=$yahoo64[((ord($source[$in+1])<<2)&0x3C) | (ord($source[$in+2])>>6)];
$dest.=$yahoo64[ord($source[$in+2])&0x3F];
$in += 3;
}
if($inlen>0)
{
// enters here :)
$dest.=$yahoo64[ord($source[$in])>>2];
$fragment = ((ord($source[$in])<<4)&0x30);
if($inlen>1){$fragment |= (ord($source[$in+1])>>4); }
$dest.=$yahoo64[$fragment];
if($inlen<2)
{$dest.="-";}
else
{$dest.=$yahoo64[((ord($source[$in+1])<<2)&0x3c)]; }
$dest.="-";
 
}

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Question by:tobjectpascal
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7 Comments
 
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Author Comment

by:tobjectpascal
ID: 24726444
Here's the C# version..

Might be easier to understand.

public static string to_y64(byte[] input) {
 
 /* raw bytes in quasi-big-endian order to base 64 string (NUL-terminated) */
 
 const string base64digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789._";
 
 int inlen=input.Length;
 char[] temp = new char[24];
 int i=0,j=0;
 
 for (;inlen >= 3;inlen -= 3) {
  temp[i++] = base64digits[input[j] >> 2];
  temp[i++] = base64digits[((input[j] << 4) & 0x30) | (input[j+1] >> 4)];
  temp[i++] = base64digits[((input[j+1] << 2) & 0x3c) | (input[j+2] >> 6)];
  temp[i++] = base64digits[input[j+2] & 0x3f];
  j += 3;
 }
 
 if (inlen > 0) {
  int fragment;
  temp[i++] = base64digits[input[j] >> 2];
  fragment = (input[j] << 4) & 0x30;
  if (inlen > 1)
   fragment |= input[j+1] >> 4;
  temp[i++] = base64digits[fragment];
  temp[i++] = (inlen < 2) ? '-' : base64digits[(input[j+1] << 2) & 0x3c];
  temp[i++] = '-';
 }
 return GetString(temp);
}

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Author Comment

by:tobjectpascal
ID: 24726912
yet another example.

static unsigned yahoobase64 (unsigned char *src, unsigned srclen, char *dst) {
	static const char *enc = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
		"abcdefghijklmnopqrstuvwxyz0123456789._";
	unsigned char *end = src + srclen;
	char *pdst = dst;
	unsigned x;
	for ( ; src < end; pdst += 4) 
		if (end - src >= 3) {
			x = (src [0] << 16) + (src [1] << 8) + src [2];
			pdst [3] = enc [x & 0x3f]; x >>= 6;
			pdst [2] = enc [x & 0x3f]; x >>= 6;
			pdst [1] = enc [x & 0x3f]; x >>= 6;
			pdst [0] = enc [x & 0x3f];
			src += 3;
			continue;
		}
		else if (end - src == 2) {
			x = (src [0] << 16) + (src [1] << 8);
			pdst [3] = '-'; x >>= 6;
			pdst [2] = enc [x & 0x3f]; x >>= 6;
			pdst [1] = enc [x & 0x3f]; x >>= 6;
			pdst [0] = enc [x & 0x3f];
			src += 2;
			continue;
		}
		else if (end - src == 1) {
			x = src [0] << 16;
			pdst [3] = '-'; x >>= 6;
			pdst [2] = '-'; x >>= 6;
			pdst [1] = enc [x & 0x3f]; x >>= 6;
			pdst [0] = enc [x & 0x3f];
			src += 1;
			continue;
		}
	*pdst = '\0';
	return pdst - dst;
}

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by:tobjectpascal
ID: 24727266
It's C code lol
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Accepted Solution

by:
ThievingSix earned 2000 total points
ID: 24733255
This should work although I can't do any debugging because I don't know what should be inputted and how it comes out. If this doesn't work the way it's supposed to give me a Input and what it should Output.
function YahooBase64(Source: PChar; SourceLen: DWORD): PChar;
const
  Enc : PChar = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789._';
var
  pEnd : PChar;
  pDst : PChar;
  X : DWORD;
begin
  pEnd := Source + SourceLen;
  Result := AllocMem(24);
  pDst := Result;
  X := 0;
  While Source < pEnd Do
    begin
    If (pEnd - Source) >= 3 Then
      begin
      X := (Byte(Source[0]) SHL 16) + (Byte(Source[1]) SHL 8) + Byte(Source[2]);
      pDst[3] := Enc[X AND $3F];
      X := X SHR 6;
      pDst[2] := Enc[X AND $3F];
      X := X SHR 6;
      pDst[1] := Enc[X AND $3F];
      X := X SHR 6;
      pDst[0] := Enc[X AND $3F];
      Inc(Source,3);
      Continue;
    end
    Else If (pEnd - Source) = 2 Then
      begin
      X := (Byte(Source[0]) SHL 16) + (Byte(Source[1]) SHL 8);
      pDst[3] := '-';
      X := X SHR 6;
      pDst[2] := Enc[X AND $3F];
      X := X SHR 6;
      pDst[1] := Enc[X AND $3F];
      X := X SHR 6;
      pDst[0] := Enc[X AND $3F];
      Inc(Source,2);
      Continue;
    end
    Else If (pEnd - Source) = 1 Then
      begin
      X := Byte(Source[0]) SHL 16;
      pDst[3] := '-';
      X := X SHR 6;
      pDst[2] := '-';
      X := X SHR 6;
      pDst[1] := Enc[X AND $3F];
      X := X SHR 6;
      pDst[0] := Enc[X AND $3F];
      Inc(Source);
      Continue;
    end;
    Inc(pDst,4);
  end;
  pDst^ := #0;
  Dec(Source,SourceLen);
end;

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Author Comment

by:tobjectpascal
ID: 24733415
wow thanks, you can have the points just for the effort I was hoping for a couple of lines of code but wow thank you :)

points are yours just for trying......
0
 
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Author Closing Comment

by:tobjectpascal
ID: 31597085
10/10 for effort thanks :)
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