Lasso functions to decode and decrypt a FoxyCart datafeed.

transaction.lasso

[

Define_Tag('Decode_Raw', -Required='input');
	Local('output' = bytes());
	Local('ndx' = 1);

	While(#ndx < #input->Length);
		if(#input->Get(#ndx) == '%');
			local: 'byte' = string(#input->Substring(#ndx+1, 2));

			#output->Import8Bits(16 * #byte->digit(1, 16) + 1 * #byte->digit(2, 16));
			#ndx += 2;	// Consume 2 hex digits
		else:
			#output->ImportString(#input->Get(#ndx), 'ascii');
		/if;
		#ndx += 1;
	/While;

	Return(#output);
/Define_Tag;

Define_Tag('rc4_decrypt', -Required='data', -Required='pwd'); 
	local: 'key' = bytes();
	local: 'box' = bytes();
	local: 'cipher' = bytes();

	local: 'pwd' = bytes(#pwd);
	local: 'pwd_length' = #pwd->Length;
	local: 'data_length' = #data->Length;

	local: 'i' = 0;
	While (#i < 256);												/* for ($i = 0; $i < 256; $i++) */
		#key->Append(#pwd->GetRange(1 + (#i % #pwd_length), 1));	/* $key[$i] = ord($pwd[$i % $pwd_length]); */
		#box->Import8Bits(#i);										/* $box[$i] = $i; */
		#i += 1;
	/While;

	local: 'i' = 0;
	local: 'j' = 0;
	local: 'out' = '';

	While (#i < 256);												/* for ($j = $i = 0; $i < 256; $i++) */
		#j = ((#j + #box->Get(1 + #i) + #key->Get(1 + #i)) % 256);	/*		$j = ($j + $box[$i] + $key[$i]) % 256;*/
		local: 'tmp' = #box->GetRange(1 + #i, 1);					/* 		$tmp = $box[$i]; */
		#box->SetRange(1 + #i, #box->GetRange(1 + #j, 1));			/* 		$box[$i] = $box[$j]; */
		#box->SetRange(1 + #j, #tmp);								/* 		$box[$j] = $tmp; */

		#i += 1;
	/While;
	
	local: 'a' = 0;
	local: 'j' = 0;
	local: 'i' = 0;

	While (#i < #data_length);								/* for ($a = $j = $i = 0; $i < $data_length; $i++) */
		#a = (#a + 1) % 256;								/* 		$a = ($a + 1) % 256; */
		#j = ((#j + #box->Get(1 + #a)) % 256);				/* 		$j = ($j + $box[$a]) % 256; */
		local: 'tmp' = #box->GetRange(1 + #a, 1);			/* 		$tmp = $box[$a]; */
		#box->SetRange(1 + #a, #box->GetRange(1 + #j, 1));	/* 		$box[$a] = $box[$j]; */
		#box->SetRange(1 + #j, #tmp);						/* 		$box[$j] = $tmp; */
		local: 'k' = #box->Get(1 + (((#box->Get(1 + #a) + #box->Get(1 + #j)) % 256)));	/* 		$k = $box[(($box[$a] + $box[$j]) % 256)]; */

		local: 'data_byte' = #data->Get(1 + #i);
		#data_byte->BitXOr(#k);
 		#cipher->Import8Bits(#data_byte);	/* 		$cipher .= chr(ord($data[$i]) ^ $k); */
		
		#i += 1;
	/While;

	
	Return(#cipher->ExportString('UTF-8'));
/Define_Tag;

include('bitformat.lasso');

var('test_raw') = action_param('foxydata');
var('test') = $test_raw;

'the data is: ';
$test;
'<br /><br /><br />';
'<br /><br /><br />';

'decoded:<br/>';
$test = Decode_Raw($test);
$test;

'<br /><br /><br />';
var('mykey')='qRaNP5H1RXQlPub6ptI4Nk3JFXTJFdgVUhDzgfuX8adMzfNNymLgyEV8wIH2';
var('foxy_sent')=rc4_decrypt: -data=$test, -pwd=$mykey;
'Here\'s what foxy sent:<br />';
$foxy_sent;

]