fbpx
Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: torture the compiler ;-)

torture the compiler ;-) 6 months 3 weeks ago #6913

  Karl-Heinz's Avatar Topic Author Karl-Heinz Offline Posts: 269
Guys,

Of course i'm not going to use the PgCrypt() func below in any production app. The only goal is to torture the compiler.:-). The code is based on a crypt routine from the Intl. VO Forum. To make the code even more unreadable i have replaced Substr() with _nGet () and the result string is build with _nPut (). :-)The function compiles with VO and X# ( 2.0.0.7 ) - and even the results are the same.

To compile the func you need the 2.0.0.7 compiler

- add references to the X# Runtime dlls
- Dialect is VO
- target is x86 !
- no specific compiler switches are required.- all settings are unchecked.

The capabilities of the x# compiler are incredible !

regards
Karl-Heinz


FUNCTION Start( ) AS VOID
LOCAL cValue AS STRING 	

	cValue := PgCrypt( "The quick brown fox jumps over the lazy dog." , "CAT" )

	Console.WriteLine( cValue) 
	
	cValue := PgCrypt( cValue , "CAT" )

	Console.WriteLine( cValue)
	
RETURN


FUNCTION PgCrypt( cString AS STRING , cKey AS STRING ) AS STRING 
LOCAL dwKLen, dwSLen AS DWORD  
LOCAL wCode1, wCode2, wRotate, wCounter, wTemp1 , wTemp2 AS WORD
LOCAL c , c1 , c2, bnibble AS BYTE
LOCAL i,j,k AS DWORD   
LOCAL cResult AS STRING 
LOCAL pszKey,pszString  AS PSZ  
LOCAL ptrResult AS PTR 

             
	dwSLen := SLen( cString ) 
	dwKLen := SLen( cKey ) 

 	IF dwSLen < 2 .AND. dwKLen < 2
		RETURN cString 
  
	ENDIF 
  
	pszString := StringAlloc ( cString )    
	pszKey := StringAlloc ( cKey )
	ptrResult := MemAlloc ( dwSLen ) 
 
	wCode1 := WORD ( _CAST , _XOR( DWORD ( PTR( _CAST , pszKey ) ) , PszLen(pszKey) ) )   
	wCode2 := 0xAAAA 
 

	j := 1
 
	FOR i := 1 TO dwSLen 
 	
		IF j > dwKLen
	   		j := 1
	   
		ENDIF 
 
		c1 := BYTE ( _CAST , _NGet ( pszString , i- 1 )  ) 
		c2 := BYTE ( _CAST , _NGet ( pszKey , j - 1  )	) 	  
		
	 	c  := BYTE ( _CAST , _XOR(  WORD( _CAST , c1 ) , WORD ( _CAST ,  c2 ) ) )  
  
		wCode1  := _XOR( wCode1 , wCode1 >> 8 )
		wRotate := _AND( wCode1 , 0xF )

		wTemp1 := wCode1
	
		FOR k := 1 TO wRotate
			wTemp1 := wTemp1 >> 1
		
		NEXT
	
		wTemp2 := wCode1
	
		FOR k := 1 TO 16-wRotate
			wTemp2 := wTemp2 << 1 
		
		NEXT
	
		wCode1  := _OR( wTemp1 , wTemp2 )
		wCode1  := _XOR( wCode1 , wCode2 )
		wCode1  := wCode1 + 0x10

  		wCounter := _AND( wCode1 , 0x1E )
		wCounter ++
		wCounter ++
        

		DO WHILE wCounter > 0
		
			wCounter --
			wRotate := _AND( wCounter , 0xF )

		 	wTemp1 := wCode2
	 	
			FOR k := 1 TO wRotate
	    		wTemp1 := wTemp1 >> 1
	    		
			NEXT
		
			wTemp2 := wCode2
		
			FOR k := 1 TO 16 - wRotate
				wTemp2 := wTemp2 << 1
				
			NEXT
		
			wCode2  := _OR( wTemp1 , wTemp2 )

   			wCode2  := _OR( wCode2 << 8 , _XOR( ( wCode2 >> 8 ) , 0xFF ) )
			wCode2  := _OR( wCode2 << 1 , wCode2 >> 15 )
			wCode2  := _XOR( wCode2 , 0xAAAA )

 			bnibble := BYTE ( _CAST , _AND( wCode2 , 0xFF ) ) 
 		
 
			wTemp1 := bnibble << 1
		
			IF wTemp1 > 255
				wTemp1 := wTemp1 - 255 
			
			ENDIF 
   
			wTemp2 := bnibble >> 7
			bnibble := BYTE ( _CAST , _OR( wTemp1 , wTemp2 ) ) 
				 
			wCode2 := _OR( _AND( wCode2 , 0xFF00 ) , bnibble )
		
			wCounter -- 
		
		ENDDO
		
		j ++
		
        _NPut ( ptrResult , i - 1 , BYTE ( _CAST ,  _XOR( WORD ( _CAST , c ) ,  WORD ( _CAST , bnibble ) ) )    ) 
        
	 NEXT
 	 
	 cResult := Mem2String ( ptrResult , dwSLen ) 
	 
//	 ? SLen ( cString ) 
//	 ? SLen ( cResult)

	 MemFree ( pszString )
	 MemFree ( pszKey ) 
	 MemFree ( ptrResult) 

	 RETURN cResult

Please Log in or Create an account to join the conversation.

torture the compiler ;-) 6 months 3 weeks ago #6914

  FFF's Avatar FFF Away Posts: 577
You mean, "security by obscurity" ;-?

Please Log in or Create an account to join the conversation.

torture the compiler ;-) 6 months 3 weeks ago #6915

  Karl-Heinz's Avatar Topic Author Karl-Heinz Offline Posts: 269
a built in .net obfuscator :-)

Please Log in or Create an account to join the conversation.

  • Page:
  • 1