Eliminate fixed token-length limit in hba.c.
Historically, hba.c limited tokens in the authentication configuration
files (pg_hba.conf and pg_ident.conf) to less than 256 bytes. We have
seen a few reports of this limit causing problems; notably, for
moderately-complex LDAP configurations. Let's get rid of the fixed
limit by using a StringInfo instead of a fixed-size buffer.
This actually takes less code than before, since we can get rid of
a nontrivial error recovery stanza. It's doubtless a hair slower,
but parsing the content of the HBA files should in no way be
performance-critical.
Although this is a pretty straightforward patch, it doesn't seem
worth the risk to back-patch given the small number of complaints
to date. In released branches, we'll just raise MAX_TOKEN to
ameliorate the problem.
Discussion: https://postgr.es/m/
1588937.
1690221208@sss.pgh.pa.us