Re: [Evolution-hackers] There's no need to be so hard on iconv

[Philip Van Hoof <spam pvanhoof be>]

On Thu, 2007-10-11 at 12:14 +0200, Philip Van Hoof wrote:
> I also have this one, for example
> 
> Subject: =?ISO-2022-JP?B?GyRCJSIlaiUsLUUtRRsoQg==?= (
>         =?ISO-2022-JP?B?GyRCITchJiZYISYbKEI=?=)o =?ISO-2022-JP?B?GyRCIlwbKEI=?=
>         =?ISO-2022-JP?B?GyRCIiglUSE8JXMbKEI=?= !!"
>         =?ISO-2022-JP?B?GyRCISMhJhsoQg==?= :*: =?ISO-2022-JP?B?GyRCISYbKEI=?=
>         =?ISO-2022-JP?B?GyRCISwheRsoQg==?=
> 
> I know that the characters " (", ")o ", " !!" and " :*: " should not be
> there (at least, I think they shouldn't), I guess this is done by spam
> bots to confuse spamassassin (not sure, though).
> 
> This check in the code (line 842 in camel-mime-utils.c) makes any such
> string become the base64 one. This is of course really not readable for
> normal human beings (although, it depends on what you call a normal
> one).
> 
> 842: .. /* quick check to see if this could possibly be a real encoded word */
> 843: ..  if (len < 8 || !(in[0] == '=' && in[1] == '?' && in[len-1] == '=' && in[len-2] == '?')) {
> 844: ..		d(printf("invalid\n"));
> 845: ..		return NULL;
> 846: ..  }
> 
> When just trying to decode the string, ignoring the check, it does work
> quite well. At least for this case.
> 
> I'm attaching yet another patch that ignores this check.


The entire check should not be ignored. The len<8 check, for example, is
important. So don't commit this patch :-)



> On Thu, 2007-10-11 at 11:52 +0200, Philip Van Hoof wrote:
> > In case iconv does not succeed in decoding for example the Subject
> > header, it returns the base64 encoded one. That is is obviously not
> > readable at all. The decoded one after base64 decoding (which did
> > succeed in my test case) or whatever iconv could recover from it, sounds
> > like a better option.
> > 
> > This changeset (patch) on camel-mime-utils.c deals with the error
> > situation (in case iconv did not return -1) by returning what(ever)
> > iconv could recover from the string:
> > 
> > http://tinymail.org/trac/tinymail/changeset/2830#file2
> > 
> > I attached:
> > 
> > svn diff libtinymail-camel/camel-lite/camel/camel-mime-utils.c -r 2829 > /home/pvanhoof/diff.diff
> > 
> > This is the Subject line of my test target:
> > 
> > Subject: =?ISO-2022-JP?B?GyRCM048QiRLOkdEY0Z8NWsbKEI=?=
> > 
> > =?ISO-2022-JP?B?GyRCIzJLfDFfIUFGfEonJCQkRyQqRU8kN0NXJDckXiQ5ISMlYSE8GyhC?=
> >         =?ISO-2022-JP?B?GyRCJWslXiUsJTglcxsoQg==?=
> > 
> > 
> > I also opened a bug for this one:
> > http://bugzilla.gnome.org/show_bug.cgi?id=485677
> > 
> > 
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-- 
Philip Van Hoof, software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://www.pvanhoof.be/blog