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From "Bill Barker" <>
Subject Re: cvs commit: jakarta-tomcat-catalina/webapps/docs changelog.xml
Date Thu, 12 May 2005 18:41:41 GMT

----- Original Message -----
From: "Mark Thomas" <>
To: "Tomcat Developers List" <>
Sent: Monday, May 12, 2003 10:34 AM
Subject: Re: cvs commit: jakarta-tomcat-catalina/webapps/docs changelog.xml

>So the issues are:
>1. AJP/1.3 compatibility
>2. Potential DoS
>As far as DoS goes, with the previous behaviour any parameters POSTed
>would be persisted in the session until the authentication was completed
>or the session timed out.  Therefore, the same issue exists with both
>the old and new implementation. (a)
>The size of the the POST is already limited by maxPostSize for both
>FORM and CLIENT-CERT auth. Is the proposal to add another parameter to
>the connector to optionally further limit the saved POST size when
>authenticating? (b)

The check on maxPostSize in the Request isn't applied to any 'chunked' POST
body, and also not to any 'multipart/form-data'.  I don't see any place else
that checks it except when CLIENT-CERT auth saves the request body.

>Given (a), I don't see a significant difference in risk between the old
>and new behaviour. I am happy to mitigate this risk by implementing (b).
>As maxPostSize applies to any POST, including during CLIENT-CERT auth my
>own view is that the new parameter should apply only to the
>FormAuthenticator valve and should default to 0 (ie no data saved). -1
>would mean use whatever value is specified for maxPostSize and any value
> >0 would be the limit unless maxPostSize was smaller in which case
>maxPostSize would override the new parameter. The docs for this
>parameter would include a health warning about the risks of permitting
>the saving of POSTed data during FORM authentication.

No.  Previously only the Parameters were saved, and limited by maxPostSize.
Now you are saving off file-upload posts as well, and these aren't limited

>I obviously also need to look at AJP/1.3 compatibility. Any hints/tips
>gratefully received.

It should be something like:

but that won't work either unless Jk-Coyote gets cleaned up a bit (the
ActionHook implementation is one of those "it's ugly but it works" things at
the moment :).  I could do the cleanup if the consensus is that this is the
way to go.

>If these issues aren't resolved by the time of the next release, I'll
>revert the saving the raw data part of the patch.

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