Re: BUG #14543: libpq fails with group readable ssl keys

On Mon, Feb 13, 2017 at 06:43:23PM +0000, postgres(at)freigeist(dot)org wrote:
> The following bug has been logged on the website:
>
> Bug reference: 14543
> Logged by: Johannes Ziemke
> Email address: postgres(at)freigeist(dot)org
> PostgreSQL version: 9.5.6
> Operating system: linux
> Description:
>
> Hi,
>
> looks like libpq checks if a ssl key is group or world readable and aborts
> if that's the case:
>
> # pg_basebackup -R -d
> 'postgres://replication(at)db-rw?sslmode=verify-ca&sslcert=/etc/ssl/private/default.pem&sslkey=/etc/ssl/private/default-key.pem&sslrootcert=/etc/ssl/ca-trusted.pem'
> -D /var/lib/postgresql/9.5/main --xlog-method=stream
> pg_basebackup: could not connect to server: private key file
> "/etc/ssl/private/default-key.pem" has group or world access; permissions
> should be u=rw (0600) or less
>
> # ls -al /etc/ssl/private/default-key.pem
> -rw-r----- 1 root ssl-cert 1675 Feb 13 18:04
> /etc/ssl/private/default-key.pem
>
>
> While I agree this is reasonable to do if the key is world readable, it's
> perfectly fine to make a SSL key group readable to share it with multiple
> users on the same system.
>
> Ubuntu (and probably most other distributions) even creates a group for
> exactly this scenario:
>
> # ls -l /etc/ssl/private/
> total 4
> -rw-r----- 1 root ssl-cert 1708 Apr 14 2016 ssl-cert-snakeoil.key

We changed Postgres 9.6 to allow open group permissions on the
_server_'s SSL key if it was owned by root:

Allow the server's <acronym>SSL</> key file to have group read
access if it is owned by <literal>root</> (Christoph Berg)

Is this something we should change on the client? I don't see why not,
but the 'root' requirement would still remain.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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