URLEncode

[learn_more]

by Max_Power

Encodes a URL so that a browser can handle it. For example if you give the url http://www.x.com/file.php?string=this is a fracking test [dood] it would return http://www.x.com/file.php?string=thi...est+%5Bdood%5D.

This is useful if you are doing stuff with google, doing CGI in MASM, or many other things.

	Encode_URL PROTO :DWORD,:DWORD
	
	.data
		szAllowed db "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz:/.?=_-$(){}~&",0
		szHexFormat db "%X",0
	
	.code
	
	Encode_URL proc USES ecx edi esi lpSource:DWORD,lpDestination:DWORD
		LOCAL szCurChar[2]:BYTE
		LOCAL szCharCode[5]:BYTE
		LOCAL dwLen:DWORD
		
		invoke lstrlen,lpSource
		mov dwLen,eax
		
		xor ecx,ecx	;Offset in source string
		xor edx,edx ;Offset is destination string
		
		.REPEAT
			;Get the current character
			mov edi,lpSource
			mov al,[edi+ecx]
			lea edi,szCurChar
			mov [edi],al
			mov al,0
			mov [edi+1],al
	
			;Check if the character is allowed
			push ecx
			push edx
			invoke InString,1,ADDR szAllowed,ADDR szCurChar
			pop edx
			pop ecx
			
			mov edi,lpDestination
			.IF eax<1
				;Check if it is a space, if so replace it with
				;a plus sign otherwise replace it with %hex val
				mov al,szCurChar
				.IF al==20h
					mov al,'+'
					mov [edi+edx],al
				.ELSE
					mov al,'%'
					mov [edi+edx],al
					
					;Convert the character code for the illegal
					;char to a string
					xor eax,eax
					mov al,szCurChar
					push ecx
					push edx
					invoke wsprintf,ADDR szCharCode,ADDR szHexFormat,eax
					pop edx
					pop ecx
					
					inc edx
					lea esi,szCharCode
					mov eax,[esi]
					mov [edi+edx],eax
					mov eax,[esi+1]
					inc edx
					mov [edi+edx],eax
				.ENDIF
			.ELSE
				mov al,szCurChar
				mov [edi+edx],al
			.ENDIF

			inc ecx
			inc edx
		.UNTIL ecx==dwLen
		
		ret
	Encode_URL endp