On Thu, Jul 25, 2019 at 2:32 AM Paul Moore firstname.lastname@example.org wrote:
On Thu, 25 Jul 2019 at 02:16, Nam Nguyen email@example.com wrote:
Back to my original requests to the list: 1) Whether we want to have a
(possibly private) parsing library in the stdlib
In the abstract, no. Propose a specific library, and that answer would change to "maybe".
I have no specific library to propose. I'm looking for a list of features such a library should have.
and 2) What features it should have.
That question only makes sense if you get agreement to the abstract proposal that "we should add a parsing library. And as I said, I don't agree to that so I can't answer the second question.
As Chris summarized it correctly, I am advocating for a general solution to individual problems (which have the same nature). We can certainly solve the problems when they are reported, or we can take a proactive approach to make them less likely to occur. I am talking about a class of input validation issues here and I thought parsing would be a very natural solution to that. This is quite similar to a context-sensitive templating library that prevents cross-site-scripting on the output side. So I don't know why (or what it takes) to convince people that it's a good thing(tm).
Generally, things go into the stdlib when they have been developed externally and proved their value. The bar for designing a whole library from scratch, "specifically" targeted at stdlib inclusion, is very high, and you're nowhere near reaching it IMO.
This is a misunderstanding. I have not proposed any from-scratch, or existing library to be used. And on this note, please allow me to make it clear once more time that I am not asking for a publicly-facing library either.
These are good points to set as targets! What does it take for me to get
the list to agree on one such set of criteria?
You need to start by getting agreement on the premise that adding a newly-written parser to the stdlib is a good idea. And so far your *only* argument seems to be that "it will avoid a class of security bugs" which I find extremely unconvincing (and I get the impression others do, too).
Why? What is unconvincing about a parsing library being able... parse (and therefore, validate) inputs?
But even if "using a real parser" was useful in that context, there's *still* no argument for writing one from scratch, rather than using an existing, proven library.
Never a goal.
At the most basic level, what if there's a bug in your new parsing library? If we're using it in security-critical code, such a bug would be a vulnerability just like the ones you're suggesting your parser would avoid. Are you asking us to believe that your code will be robust enough to trust over code that's been used in production systems for years?
I think you need to stop getting distracted by details, and focus on your stated initial request "Whether we want to have a (possibly private) parsing library in the stdlib". You don't seem to me to have persuaded anyone of this basic suggestion yet,
Good observation. How do I convince you that complex input validation tasks should be left to a parser?