Re: password problems

On 10/07/2011 10:14 PM, Alexander James Spence [axs] wrote:

> We have updated our server to 9.1 the previous version used am external
> file for authentication (unix crypt)

PostgreSQL's basic auth scheme hasn't changed in a long time, so it's
pretty unlikely that the previous version inherently used an external
file for auth. Is it possible the previous version was _configured_ to,
via pg_hba.conf ?

If not: Which previous version, exactly? On what OS and (if linux)
distro? What was the external file called, where was it and what is its
format? Are you talking about /etc/passwd or something else?

Is it possible you were authenticating via OS usernames and passwords
before, by using the pluggable authentication modules (PAM) subsystem in
your OS via pg_hba.conf?

> Can I continue to use this file if so how is it referenced in pg_hba.conf?

Alas, my psychic powers are insufficient to answer this question.
Perhaps if you said something about what the file is and where it is...

See the manual:

http://www.postgresql.org/docs/current/static/auth-pg-hba-conf.html

for more info on pg_hba.conf, in particular the auth-method section and
the elaboraton of it given in this manual page, which the pg_hba.conf
page links to:

http://www.postgresql.org/docs/current/static/auth-methods.html

> If I want to continue to use unix crypt passwords how do I get them into
> the database. I have seen references to crypt and gen_salt but cannot
> get these to work.

Do you refer to pgcrypto? (Tip: If you refer to something, link to it so
others know for certain what you're talking about).

http://www.postgresql.org/docs/current/interactive/pgcrypto.html

If so: that's for application-level crypto work, when your app wants to
do crypto in the database. For database user authentication you probably
want ALTER USER:

http://www.postgresql.org/docs/current/interactive/sql-alteruser.html

As far as I know, PostgreSQL's default built-in user database uses a
salted md5 hash for user passwords. This will prevent you from copying
existing `crypt'ed passwords over directly into PostgreSQL's internal
user list, as it's a different hash algorithm. You should still be able
to use other auth methods like PAM to use them, though.

--
Craig Ringer