CentOS docs - Apr 2019 - firewalld configuration for securing SSH

Thank you, I've gone in and made the listed changes changed firewalld
sections to use services instead of just port numbers.

-- Kimee


On Wed, 2019-04-24 at 17:05 -0700, Akemi Yagi wrote:
> On Wed, Apr 24, 2019 at 12:13 AM Kimberlee Integer Model
> <kimee.i.model at gmail.com> wrote:
> > 
> > HI all,
> > 
> > 1st time contributor here. I was using the guide on securing SSH,
> > and
> > noticed that the firewall-cmd snippets for filtering by requests
> > per
> > time seem somewhat outdated. From what I can tell the given
> > snippets,
> > relay arguments directly down to iptables, and do not cover both
> > IPv4
> > and v6. (and in fact when attempting to extend to v6 the firewall
> > would
> > fail to reload). I came up with an "all firewall-cmd"
solution
> > which
> > I'd like to share.
> > 
> > It boils down to using rich rules in firewalld instead of direct
> > rules
> > for iptables. The code snippets in section 6 of <
> > https://wiki.centos.org/HowTos/Network/SecuringSSH>; would be
> > changed to
> > 
> > firewall-cmd --permanent --add-rich-rule='rule port
port="22"
> > protocol="tcp" accept limit value="4/m"'
> > firewall-cmd --permanent --remove-service ssh
> > firewall-cmd --permanent --remove-port 22/tcp
> > firewall-cmd --reload
> > 
> > newly minted wiki username is "KimeeModel".
> > 
> > Regards,
> > Kimee
> 
> You should be able to edit that page. Let us know if you find any
> problem.
> 
> Akemi
> _______________________________________________
> CentOS-docs mailing list
> CentOS-docs at centos.org
> https://lists.centos.org/mailman/listinfo/centos-docs

Hi there,

Wouldn't that be a better solution to create a custom xml file to put
in /etc/firewalld and load that "ssh-custom" service instead ?

Thanks

On 26/04/2019, Kimberlee Integer Model <kimee.i.model at gmail.com>
wrote:
> Thank you, I've gone in and made the listed changes changed firewalld
> sections to use services instead of just port numbers.
>
> -- Kimee
>
>
> On Wed, 2019-04-24 at 17:05 -0700, Akemi Yagi wrote:
>> On Wed, Apr 24, 2019 at 12:13 AM Kimberlee Integer Model
>> <kimee.i.model at gmail.com> wrote:
>> >
>> > HI all,
>> >
>> > 1st time contributor here. I was using the guide on securing SSH,
>> > and
>> > noticed that the firewall-cmd snippets for filtering by requests
>> > per
>> > time seem somewhat outdated. From what I can tell the given
>> > snippets,
>> > relay arguments directly down to iptables, and do not cover both
>> > IPv4
>> > and v6. (and in fact when attempting to extend to v6 the firewall
>> > would
>> > fail to reload). I came up with an "all firewall-cmd"
solution
>> > which
>> > I'd like to share.
>> >
>> > It boils down to using rich rules in firewalld instead of direct
>> > rules
>> > for iptables. The code snippets in section 6 of <
>> > https://wiki.centos.org/HowTos/Network/SecuringSSH>; would be
>> > changed to
>> >
>> > firewall-cmd --permanent --add-rich-rule='rule port
port="22"
>> > protocol="tcp" accept limit value="4/m"'
>> > firewall-cmd --permanent --remove-service ssh
>> > firewall-cmd --permanent --remove-port 22/tcp
>> > firewall-cmd --reload
>> >
>> > newly minted wiki username is "KimeeModel".
>> >
>> > Regards,
>> > Kimee
>>
>> You should be able to edit that page. Let us know if you find any
>> problem.
>>
>> Akemi
>> _______________________________________________
>> CentOS-docs mailing list
>> CentOS-docs at centos.org
>> https://lists.centos.org/mailman/listinfo/centos-docs
>
> _______________________________________________
> CentOS-docs mailing list
> CentOS-docs at centos.org
> https://lists.centos.org/mailman/listinfo/centos-docs
>

I'm not sure I follow, you just think the modified one should be called
"ssh-custom", or you think there shouldn't be a modified service
file
at all?

-- Kimee

On Fri, 2019-04-26 at 19:46 +0200, Thibaut Perrin wrote:
> Hi there,
> 
> Wouldn't that be a better solution to create a custom xml file to put
> in /etc/firewalld and load that "ssh-custom" service instead ?
> 
> Thanks
> 
> On 26/04/2019, Kimberlee Integer Model <kimee.i.model at gmail.com>
> wrote:
> > Thank you, I've gone in and made the listed changes changed
> > firewalld
> > sections to use services instead of just port numbers.
> > 
> > -- Kimee
> > 
> > 
> > On Wed, 2019-04-24 at 17:05 -0700, Akemi Yagi wrote:
> > > On Wed, Apr 24, 2019 at 12:13 AM Kimberlee Integer Model
> > > <kimee.i.model at gmail.com> wrote:
> > > > 
> > > > HI all,
> > > > 
> > > > 1st time contributor here. I was using the guide on securing
> > > > SSH,
> > > > and
> > > > noticed that the firewall-cmd snippets for filtering by
> > > > requests
> > > > per
> > > > time seem somewhat outdated. From what I can tell the given
> > > > snippets,
> > > > relay arguments directly down to iptables, and do not cover
> > > > both
> > > > IPv4
> > > > and v6. (and in fact when attempting to extend to v6 the
> > > > firewall
> > > > would
> > > > fail to reload). I came up with an "all
firewall-cmd" solution
> > > > which
> > > > I'd like to share.
> > > > 
> > > > It boils down to using rich rules in firewalld instead of
> > > > direct
> > > > rules
> > > > for iptables. The code snippets in section 6 of <
> > > > https://wiki.centos.org/HowTos/Network/SecuringSSH>;;
would be
> > > > changed to
> > > > 
> > > > firewall-cmd --permanent --add-rich-rule='rule port
port="22"
> > > > protocol="tcp" accept limit
value="4/m"'
> > > > firewall-cmd --permanent --remove-service ssh
> > > > firewall-cmd --permanent --remove-port 22/tcp
> > > > firewall-cmd --reload
> > > > 
> > > > newly minted wiki username is "KimeeModel".
> > > > 
> > > > Regards,
> > > > Kimee
> > > 
> > > You should be able to edit that page. Let us know if you find any
> > > problem.
> > > 
> > > Akemi
> > > _______________________________________________
> > > CentOS-docs mailing list
> > > CentOS-docs at centos.org
> > > https://lists.centos.org/mailman/listinfo/centos-docs
> > 
> > _______________________________________________
> > CentOS-docs mailing list
> > CentOS-docs at centos.org
> > https://lists.centos.org/mailman/listinfo/centos-docs
> > 
> 
> _______________________________________________
> CentOS-docs mailing list
> CentOS-docs at centos.org
> https://lists.centos.org/mailman/listinfo/centos-docs