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RE: zlib issue

From: Fred Covely <fcovely@bcftech.com>
Date: Tue, 12 Mar 2002 20:38:17 -0500 (EST)
To: <Phil.Nitschke@youramigo.com>
Cc: <www-lib@w3.org>
Message-ID: <NDBBIGEEOLAKIPFCDMLNCENCHLAA.fcovely@bcftech.com>
After looking at that, it does not appear that is my problem, mine seems to
be something more fundamental in libwww.  I have a fix in but must be
building libwww in such a way that it does not work.  If I strip the zlib
header bytes of the data, it all works great, so for the moment I am going
with that approach.

thx
fhc

Fred Covely
BCF Technology
fcovely@bcftech.com
(B)760-631-8157
(C)760-717-9689

-----Original Message-----
From: www-lib-request@w3.org [mailto:www-lib-request@w3.org]On Behalf Of
Phil Nitschke
Sent: Tuesday, March 12, 2002 5:22 PM
To: Fred Covely
Cc: www-lib@w3.org
Subject: Re: zlib issue


>>>>> "FC" == Fred Covely <fcovely@bcftech.com> writes:

  FC> Is anyone else have problems with sites that send back gzip
  FC> encoded data?

  FC> For example, if I do a simple HTTP Get on www.google.com accepting
  FC> gzip, I get no output.  I have traced this to htzip.c where the
  FC> call to the zlib function 'inflate' returns -3 (bad gzip format).
  FC> By various manueverings I can force it to accept the google zip
  FC> data, but I have been unable to make it work with 5.3.2.

  FC> FYI here is more detail on the work around.

  FC> The data that comes in from google is in gzip format and contains
  FC> the gzip header.  htzip.c seems to choke on the header piece, so I
  FC> borrowed a piece of code from zlib itself that reads past the
  FC> header before calling 'inflate'.  With that fix in libwww seems to
  FC> work fine.  I feel I am definitely missing something as I can't
  FC> believe others are not retrieving gzip encoded data.

Hi Fred,

Have you read the CERTŪ Advisory CA-2002-07 titled "Double Free Bug in
zlib Compression Library"?
   http://www.cert.org/advisories/CA-2002-07.html

While I'm not suggesting that this is the cause of the problem you're
seeing, it still may be advisable to review which version of zlib you're
using.

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Received on Thursday, 14 March 2002 03:27:09 GMT

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