IPP Mail Archive: Re: RE: IPP> MOD> Issue 1.19 [REVISITED - charset not

Re: RE: IPP> MOD> Issue 1.19 [REVISITED - charset not

Hugo Parra (HPARRA@novell.com)
Mon, 09 Nov 1998 11:45:14 -0700

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Carl wrote:

As an implementor, I'd really prefer to be allowed to bail as soon as a =
syntax error is detected. It can be dangerous to proceed. For example, =
the parser might be expecting the next field to be an attribute length, =
but if it's actually a string or something, due to a syntax error, the =
parser might end up trying to allocate a string buffer of a gazillion =
bytes, crashing the application. Of course, you can build in protection =
against this kind of thing, and scan for patterns to try to resynch to the =
data stream, etc. But that all adds complexity.

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Though I agree that it is generally dangerous to proceed parsing a message =
that has already been determined to be invalid, the risk of parsing up to =
the "attribute charset" attribute is next to none-existent given that it =
is always found at the exact same location in the IPP message. If the =
"attribute-charset" attribute is itself corrupted, the parser must know =
how to handle it whether a problem has already been detected with the =
message or not.

-Hugo