Fwd: [cpan #13025] parsing bug in HTTP::Message::parse()

i'm not sure if this made it to the list, so I'm reposting.

Begin forwarded message:

> From: Brian Hirt <[email protected]>
> Date: August 31, 2005 12:34:21 PM MDT
> To: [email protected]
> Cc: [email protected], Brian Hirt <[email protected]>
> Subject: Re: [cpan #13025] parsing bug in HTTP::Message::parse()
>
>
> Any news on getting this fixed?
>
> I've rewritten my test program to be more simple and i will explain  
> what is wrong, including sample output.  hopefully this clears up  
> the prior confusion with my previous bug reports.
>
> --------PROGRAM----------
>
> #!/usr/bin/perl -w
>
> use strict;
>
> use HTTP::Message;
> use HTTP::Headers;
> use Data::Dumper;
>
> my $content = '------------0xKhTmLbOuNdArY
> Content-Disposition: form-data; name="correct"
>
> some data
> ------------0xKhTmLbOuNdArY
> Content-Disposition: form-data; name="incorrect"
>
> aoeu:aoeu
> ------------0xKhTmLbOuNdArY--
> ';
>
> my $headers = HTTP::Headers->new;
> $headers->header( 'content-type' => 'multipart/form-data;  
> boundary=----------0xKhTmLbOuNdArY' );
> my $m = HTTP::Message->new($headers,$content);
>
> foreach my $part ($m->parts)
> {
>   print STDERR Dumper($part);
> }
>
>
>
> ------OUTPUT----------
>
> $VAR1 = bless( {
>                  '_content' => 'some data',
>                  '_headers' => bless( {
>                                         'content-disposition' =>  
> 'form-data; name="correct"'
>                                       }, 'HTTP::Headers' )
>                }, 'HTTP::Message' );
> $VAR1 = bless( {
>                  '_content' => '',
>                  '_headers' => bless( {
>                                         'content-disposition' =>  
> 'form-data; name="incorrect"',
>                                         '
> aoeu' => 'aoeu'
>                                       }, 'HTTP::Headers' )
>                }, 'HTTP::Message' );
>
> What's wrong:  The 2nd Part shows no content and lists "\naoeu" =>  
> 'aoeu' as a header.   'aoeu:aoeu' should be the content.  The  
> parser is parsing the content of the message.   It should not be.   
> Once the blank line is reached, it's the beginning of the content  
> and should no longer be parsed.
>
> Here is the current parse() function:
>
> sub parse
> {
>     my($class, $str) = @_;
>
>     my @hdr;
>     while (1) {
>         if ($str =~ s/^([^ \t:]+)[ \t]*: ?(.*)\n?//) {
>             push(@hdr, $1, $2);
>             $hdr[-1] =~ s/\r\z//;
>         }
>         elsif (@hdr && $str =~ s/^([ \t].*)\n?//) {
>             $hdr[-1] .= "\n$1";
>             $hdr[-1] =~ s/\r\z//;
>         }
>         else {
>             $str =~ s/^\r?\n//;
>             last;
>         }
>     }
>
>     new($class, \@hdr, $str);
> }
>
> When the part is being parsed, the first REGEX is matching past the  
> end of the headers and into the content.  This is because the ([^  
> \t:]+) goes past blank line that is supposed to be the end of the  
> headers and into the content.   One way to fix this is to change  
> the code so that it checks for the end of the headers as a last  
> part of the loop.
>
> sub parse
> {
>     my($class, $str) = @_;
>
>     my @hdr;
>     while (1) {
>         if ($str =~ s/^([^ \t:]+)[ \t]*: ?(.*)\n?//) {
>             push(@hdr, $1, $2);
>             $hdr[-1] =~ s/\r\z//;
>         }
>         elsif (@hdr && $str =~ s/^([ \t].*)\n?//) {
>             $hdr[-1] .= "\n$1";
>             $hdr[-1] =~ s/\r\z//;
>         }
>
>         # check to see if we are at the end of the headers.
>         if ($str =~ /^\r?\n/) {
>             $str =~ s/^\r?\n//;
>             last;
>         }
>     }
>
>     new($class, \@hdr, $str);
> }
>
> Please contact me if there is still confusion with this.
>
> Best Regards,
>
>
> Brian Hirt
>
>
> On Aug 15, 2005, at 2:12 AM, Brian Hirt wrote:
>
>
>> FYI, i'm not the only one seeing this bug.
>>
>> Begin forwarded message:
>>
>>
>>
>>> From: " via RT" <[email protected]>
>>> Date: August 13, 2005 8:55:10 PM MDT
>>> To: [email protected]
>>> Subject: [cpan #13025] parsing bug in HTTP::Message::parse()
>>> Reply-To: [email protected]
>>>
>>>
>>> Full context and any attached attachments can be found at:
>>> <URL: http://rt.cpan.org/NoAuth/Bug.html?id=13025 >
>>>
>>> [guest - Mon May 30 19:20:21 2005]:
>>>
>>>
>>>
>>>
>>>> Hi!
>>>>
>>>> I've stumbled across a bug in multi-part messages in HTTP::Message.
>>>>    If the message content contains something that looks like a  
>>>> header,
>>>>    it accidentally gets detected as a header.   However, a blank  
>>>> line
>>>>    after a header should signal the end of headers, and below  
>>>> it, the
>>>>    start of content as per the spec.  It just looks like your regex
>>>>    needs some tweeking, or maybe do something like this:
>>>>
>>>>
>>>>
>>>
>>> Found the same problem today... :(
>>>
>>>   #!/usr/bin/perl
>>>   use strict;
>>>   use warnings;
>>>   use HTTP::Message;
>>>   use Data::Dumper;
>>>
>>>   my $bad = qq(Content-Disposition: form-data; name="fetch_url"\n)
>>>       . qq(\nhttp://www.jbisbee.com/\n);
>>>   my $part = HTTP::Message->parse($bad);
>>>   warn Dumper($part);
>>>
>>> With the output...
>>>
>>>   $VAR1 = bless( {
>>>     '_content' => '',
>>>     '_headers' => bless( {
>>>       'content-disposition' => 'form-data; name="fetch_url"',
>>>       '                                  '
>>> http' => '//www.jbisbee.com/'
>>>     }, 'HTTP::Headers' )
>>>   }, 'HTTP::Message' );
>>>
>>> of course this only happens with forms that specify
>>>
>>>   enctype="multipart/form-data"
>>>
>>> for uploads so it may be a bit hard to reproduce
>>>
>>>
>>>
>>
>>
>
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> http://www.mobygames.com
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