On Tue, Nov 06, 2007 at 02:34:46PM +0100, Adrian Bunk wrote: > On Tue, Nov 06, 2007 at 07:49:26AM -0500, Kyle Moffett wrote: > > On Nov 06, 2007, at 07:23:36, Ahmed S. Darwish wrote: > >> On 11/6/07, Adrian Bunk <[EMAIL PROTECTED]> wrote: > >>> On Tue, Nov 06, 2007 at 01:34:05PM +0200, Ahmed S. Darwish wrote: > >>>> As far as I understand the problem now, isspace() accepts the 0xa0 > >>>> character which might collide with some of UTF-8 encoded characters > >>>> cause the high bit is set. > >> > >> I admit I'm not experienced in such encoding stuff, but shouldn't the > >> ASCII and the ASCII-compatible UTF-8 encodings be enough for the labels? > >> > >>> It would not work if someone would e.g. give you UTF-16 encoded strings, > >>> but I don't see this happening in practice. > >> > >> Won't this complicate the code too much ? > > > > Well the VFS (for example) certainly doesn't support any encodings other > > than various extended-ASCII forms (which includes UTF-8). Something like > > UTF-16 has extra null characters in-between every normal character, and as > > such would fail completely if passed to the VFS. > > Good point. > > > Personally I think that isspace() accepting character 0xA0 is a bug, as > > there are several variants of extended ASCII only one of which has that > > character as a space. Others have it as ?? (accented A), etc. > > But even then Smack would still have a similar problem with isgraph(). >
Great, To summarize the discussion. Will there be a problem in accepting ASCII and the UTF-8 ASCII _subset_ _only_ and return -EINVAL for all other cases/ecnodings ?. i.e. The fragment I sent in a previous message: /* Filter UTF-8 non-ascii compatible bytes (> 0x7F) */ if (!isascii(c)) return -EINVAL; /* Filter unwanted ascii chars */ if (!isspace(c) && !isgraph(c)) return -EINVAL; > > In addition > > the "canonical" internal text format of the kernel is UTF-8 as that > > encoding can represent any character in any other encoding and it is > > backwards-compatible with traditional ASCII. > > > > Cheers, > > Kyle Moffett- > > cu > Adrian > -- Ahmed S. Darwish Homepage: http://darwish.07.googlepages.com Blog: http://darwish-07.blogspot.com - To unsubscribe from this list: send the line "unsubscribe linux-security-module" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html