bugGNU Wget - Bugs: bug #39175, Header value length limited with...


bug #39175: Header value length limited with 256

Submitted by:  Anton <antonscherbakov>
Submitted on:  Thu Jun 6 06:27:39 2013  
Category: Protocol IssueSeverity: 3 - Normal
Priority: 5 - NormalStatus: In Progress
Privacy: PublicAssigned to: None
Originator Name: Header value lengthOpen/Closed: Open
Release: 1.13.4Operating System: GNU/Linux
Reproducibility: Every TimeFixed Release: None
Planned Release: NoneRegression: None
Work Required: NonePatch Included: None

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Thu Mar 12 14:48:53 2015, comment #2:

I did some research and the standard imposes no limits to the size of each header field name or value. Other projects go about setting at least 8Kb per header file. (Apache HTTP Server https://httpd.apache.org/docs/2.2/mod/core.html#limitrequestfieldsize, nginx 4-8Kb).

Filenames usually can't be larger than 255 bytes, but I suggest we either change to hdrval[8190] or allow for arbitrary size headers and use resp_header_strdup instead of resp_header_copy.

Miquel Llobet <mllobet>
Sat Nov 2 10:54:05 2013, comment #1:

despite that it is not the correct fix, I have increased the limit to 512 for now. It should make more difficult for this error to happen.

Giuseppe Scrivano <gscrivano>
Project Administrator
Thu Jun 6 06:27:39 2013, original submission:

I foun out that command line like this:
wget -N --debug --content-disposition --restrict-file-names=nocontrol http://data.mos.ru/datasets/download/499

saves file with "bad" file name - "499" dispite of there is Content-Disposition filename in HTTP header. The reason is that filename is rather long and there is limit size for header value - it is hard coded in http.c:1547

char hdrval[256];

Situation may be reproduced by including in responce header linelike this:

Content-Disposition: attachment; filename="aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"

All value in this case (starting with "attachment") is 280 bytes long.

I didn't find standard limit for values in header, but as I understood there is limit for all header (8-48Kb).

Anton <antonscherbakov>


(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

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    Follows 1 latest change.

    Date Changed By Updated Field Previous Value => Replaced By
    Sat Nov 2 10:54:05 2013gscrivanoStatusNone=>In Progress

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