Re: PAM authentication fails for local UNIX users

[Andrew Dunstan <andrew(at)dunslane(dot)net>]

Zdenek Kotala wrote:
> The problem what Dhanaraj tries to address is how to secure solve 
> problem with PAM and local user. Other servers (e.g. sshd) allow to 
> run master under root (with limited privileges) and forked process 
> under normal user. But postgresql
> requires start as non-root user. It limits to used common pattern.
>
> There is important question:
>
> Is current requirement to run postgresql under non-root OK? If yes, 
> than we must update PAM documentation to explain this situation which 
> will never works secure. Or if we say No, it is stupid limitation (in 
> case when UID 0 says nothing about user's privileges) then we must 
> start discussion about solution.

For now I think we should update the docs. You really can't compare 
postgres with sshd - ssh connections are in effect autonomous. I suspect 
the changes involved in allowing us to  run as root and then give up 
privileges safely would be huge, and the gain quite small.

I'd rather see an HBA fallback mechanism, which I suspect might overcome 
most of the  problems being encountered here.

cheers

andrew