[MPlayer-dev-eng] http stream basic auth base64_encode() fix

[Jeff D'Angelo]

On Mon, 6 Mar 2006, Reimar Döffinger wrote:

> Hi,
> It's late so excuse any thinking-errors...
>
> >  		} else {
> > -			// Terminate with Mime style '='
> > -			*out = '=';
> > -			outLen++;
> > -
> > -			return outLen;
> > +			// Pad with 0 to 2 '=' chars as needed
> > +			if (outLen & 3)
> > +				memset(out, '=', 4 - (outLen & 3) );
> > +			return (outLen + 3) & ~3;
>
> Actually, IMHO memset is actually not a good idea in this case, I
> prefer your old patch in this regard.
> The real reason I posted my patch is because you do not check the maxlen
> value here and might be writing beyond the buffer.

Ahh I see it now.  I was relying on the while( outLen<outMax ) loop to
keep things in check as that would run after the last encode set.
Rounding outLen down to be divisible by 4 should cover that.

> So I think the best solution would be your original patch + my
> maxlen &= ~3;
> line.

Ok, how's this attached patch look?  I added a couple speed ups to my
original.

-- 
Jeff

> Greetings,
> Reimar Döffinger
>
> _______________________________________________
> MPlayer-dev-eng mailing list
> MPlayer-dev-eng at mplayerhq.hu
> http://mplayerhq.hu/mailman/listinfo/mplayer-dev-eng
>
-------------- next part --------------
Index: http.c
===================================================================
RCS file: /cvsroot/mplayer/main/libmpdemux/http.c,v
retrieving revision 1.34
diff -u -r1.34 http.c
--- http.c	9 Feb 2006 14:07:57 -0000	1.34
+++ http.c	7 Mar 2006 16:21:49 -0000
@@ -659,7 +659,7 @@
 
 int 
 base64_encode(const void *enc, int encLen, char *out, int outMax) {
-	static const char	b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
+	static const char	b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
 
 	unsigned char		*encBuf;
 	int			outLen;
@@ -670,6 +670,7 @@
 	outLen = 0;
 	bits = 0;
 	shift = 0;
+	outMax &= ~3;
 
 	while( outLen<outMax ) {
 		if( encLen>0 ) {
@@ -685,9 +686,12 @@
 			bits <<= 6 - shift;
 			shift = 6;
 		} else {
-			// Terminate with Mime style '='
-			*out = '=';
-			outLen++;
+			// As per RFC 2045, section 6.8,
+			// pad output as necessary: 0 to 2 '=' chars.
+			while( outLen & 3 ){
+				*out++ = '=';
+				outLen++;
+			}
 
 			return outLen;
 		}