Re: [TODO] Process pg_hba.conf keywords as case-insensitive

>On 16 July 2014 23:12, Tom Lane wrote
>>Christoph Berg <cb(at)df7cb(dot)de> writes:
>> Re: Viswanatham kirankumar 2014-07-16
>> <EC867DEF52699D4189B584A14BAA7C2165440538(at)blreml504-mbx(dot)china(dot)huawei(dot)com>
>>> Attached patch is implementing following TODO item Process
>>> pg_hba.conf keywords as case-insensitive

>> Hmm. I see a case for accepting "ALL" (as in hosts.allow(5)), so +1 on
>> that, but I don't think the other keywords like "host" and "peer"
>> should be valid in upper case.

> I think the argument was that SQL users are accustomed to thinking that keywords are
> case-insensitive. It makes sense to me that we should adopt that same convention in pg_hba.conf.

>Re-reading the original thread, there was also concern about whether
>we should try to make quoting/casefolding behave more like it does in SQL,
>specifically for matching pg_hba.conf items to SQL identifiers (database and role names).
>This patch doesn't seem to have addressed that part of it, but I think we need to think those
>things through before we just do a blind s/strcmp/pg_strcasecmp/g. Otherwise we might
>find that we've added ambiguity that will give us trouble when we do try to fix that.

I had updated as per you review comments

1) database and role names behave similar to SQL identifiers (case-sensitive / case-folding).

2) users and user-groups only requires special handling and behavior as follows
Normal user :
A. unquoted ( USER ) will be treated as user ( downcase ).
B. quoted ( "USeR" ) will be treated as USeR (case-sensitive).
C. quoted ( "+USER" ) will be treated as normal user +USER (i.e. will not be considered as user-group) and case-sensitive as string is quoted.
User Group :
A. unquoted ( +USERGROUP ) will be treated as +usergruop ( downcase ).
B. plus quoted ( +"UserGROUP" ) will be treated as +UserGROUP (case-sensitive).

3) Host name is not a SQL object so it will be treated as case-sensitive
except for all, samehost, samenet are considered as keywords.
For these user need to use quotes to differentiate between hostname and keywords.

4) All the fixed keywords mention in pg_hba.conf and Client Authentication section will be considered as keywords
Eg: host, local, hostssl etc..

Thanks & Regards,
VISWANATHAM KIRAN KUMAR
HUAWEI TECHNOLOGIES INDIA PVT. LTD.