Re: Rejecting weak passwords

"Albe Laurenz" <laurenz(dot)albe(at)wien(dot)gv(dot)at> wrote:

> I wrote:
> > Following the discussions in
> > http://archives.postgresql.org/pgsql-hackers/2009-09/msg01766.php
> > and
> > http://archives.postgresql.org/pgsql-hackers/2009-10/msg00025.php ,
> > here are patches for
> >
> > a) a hook in backend/commands/user.c that allows one to add
> > password checking functions
> > b) a contrib module that makes use of the hook and
> > c) documentation for the contrib module.
>
> I found a small but embarrassing bug - here is another version.

I've reviewed your patch. The rough approach looks fine,
but I have some comments about function declarations and coding style.

The hook in core is declared as:
typedef int(*check_password_hook_type)(char * const username, char * const password);

but result type is actually treated as a boolean. So, it also should
declared as bool. Also, the type of arguments should be "const char *".

There several comments in contrib/passwordcheck.

- We don't need #ifdef PG_MODULE_MAGIC because the module works
only on 8.5 or later; PG_MODULE_MAGIC is always defined there.

- _PG_fini() is never called in HEAD anymore. Please remove it.

- The function declaration of _PG_init() should be _PG_init(void).

- isalpha() should be called as isalpha((unsigned char) c)
because it could be crashed by multi-byte characters.

- "8 characters long" would be better if it is configurable easily.
I don't think it is to be a GUC varable, but #define should be used.

- The logic in "check if the password contains only letters" should be
"check if the password contains both upper-case, lower-case and
non-alphabet letters". Passwords like "12345678' are not enough.

- Coding style should more follow postgres. For example, posisions
of '{', usage of spaces and linebreaks.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center