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Wed, 27 Jul 2022 11:06:25 +0200 (CEST) Date: Wed, 27 Jul 2022 11:06:19 +0200 From: Fabian =?iso-8859-1?q?Gr=FCnbichler?= To: Oguz Bektas , pve-devel@lists.proxmox.com References: <20220602072450.55209-1-o.bektas@proxmox.com> <20220602072450.55209-6-o.bektas@proxmox.com> In-Reply-To: <<20220602072450.55209-6-o.bektas@proxmox.com> MIME-Version: 1.0 User-Agent: astroid/0.15.0 (https://github.com/astroidmail/astroid) Message-Id: <1658908644.pyw4dmc60o.astroid@nora.none> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-SPAM-LEVEL: Spam detection results: 0 AWL 0.013 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment POISEN_SPAM_PILL 0.1 Meta: its spam POISEN_SPAM_PILL_1 0.1 random spam to be learned in bayes POISEN_SPAM_PILL_3 0.1 random spam to be learned in bayes SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [PATCH v4 access-control 05/18] api: allow superusers to edit tfa and password settings X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 27 Jul 2022 09:06:57 -0000 On June 2, 2022 9:24 am, Oguz Bektas wrote: > - prevent non-SU to change SU passwords > - warning messages on raise_perm_exc() > - log who did the password change > - has_superuser_anywhere helper >=20 > Suggested-by: Fabian Gr=C3=BCnbichler > Signed-off-by: Oguz Bektas > --- > src/PVE/API2/AccessControl.pm | 24 ++++++++++++++---------- > src/PVE/API2/TFA.pm | 16 +++++++++++++++- > src/PVE/RPCEnvironment.pm | 15 +++++++++++++++ > 3 files changed, 44 insertions(+), 11 deletions(-) >=20 > diff --git a/src/PVE/API2/AccessControl.pm b/src/PVE/API2/AccessControl.p= m > index 5d78c6f..2a584ab 100644 > --- a/src/PVE/API2/AccessControl.pm > +++ b/src/PVE/API2/AccessControl.pm > @@ -378,23 +378,27 @@ __PACKAGE__->register_method ({ > =20 > $rpcenv->check_user_exist($userid); > =20 > + my $is_superuser =3D $rpcenv->check($authuser, "/access", ['SuperUser']= , 1); > + > if ($authuser eq 'root@pam') { > # OK - root can change anything > - } else { > - if ($authuser eq $userid) { > - $rpcenv->check_user_enabled($userid); > - # OK - each user can change its own password > - } else { > - # only root may change root password > - raise_perm_exc() if $userid eq 'root@pam'; > - # do not allow to change system user passwords > - raise_perm_exc() if $realm eq 'pam'; > + } elsif ($authuser eq $userid) { > + $rpcenv->check_user_enabled($userid); > + # OK - each user can change its own password > + } else { # changing someone else's password > + raise_perm_exc("only root\@pam may change their password!\n") if $u= serid eq 'root@pam'; > + raise_perm_exc("changing system user passwords is not allowed!\n") = if $realm eq 'pam'; > + > + if (!$is_superuser) { > + # check if the target user has SU privileges > + raise_perm_exc("only superusers can change another superuser's passwor= d!\n") > + if $rpcenv->has_superuser_anywhere($userid); > } > } > =20 > PVE::AccessControl::domain_set_password($realm, $ruid, $param->{passwor= d}); > =20 > - PVE::Cluster::log_msg('info', 'root@pam', "changed password for user '$= userid'"); > + PVE::Cluster::log_msg('info', "$authuser", "changed password for user '= $userid'"); > =20 > return undef; > }}); > diff --git a/src/PVE/API2/TFA.pm b/src/PVE/API2/TFA.pm > index bee4dee..c1cdd5e 100644 > --- a/src/PVE/API2/TFA.pm > +++ b/src/PVE/API2/TFA.pm > @@ -96,22 +96,36 @@ my $TFA_UPDATE_INFO_SCHEMA =3D { > }; > =20 > # Only root may modify root, regular users need to specify their passwor= d. > +# Only users with SU on /access may modify other users with SU anywhere > # > # Returns the userid returned from `verify_username`. > # Or ($userid, $realm) in list context. > my sub root_permission_check : prototype($$$$) { > my ($rpcenv, $authuser, $userid, $password) =3D @_; > =20 > + # authuser =3D the user making the change > + # userid =3D the user to be changed > + > + if ($userid eq 'root@pam') { > + raise_perm_exc("only root\@pam may edit themselves!\n") > + if $authuser ne 'root@pam'; > + } if ($foo && $bar) { baz(); } or baz() if $foo && $bar; also, the escaping can be avoided if you just quote with '' instead of=20 "" in the message. > + > ($userid, undef, my $realm) =3D PVE::AccessControl::verify_username(= $userid); > $rpcenv->check_user_exist($userid); > =20 > - raise_perm_exc() if $userid eq 'root@pam' && $authuser ne 'root@pam'= ; > + my $is_superuser =3D $rpcenv->check($authuser, "/access", ['SuperUse= r'], 1); only used once, inside the next if, please move it there (I told you=20 this already?) > =20 > # Regular users need to confirm their password to change TFA setting= s. > if ($authuser ne 'root@pam') { > raise_param_exc({ 'password' =3D> 'password is required to modify TFA d= ata' }) > if !defined($password); > =20 > + if (!$is_superuser && $authuser ne $userid) { > + raise_perm_exc("only superusers can change another superuser's TFA = settings!\n") > + if $rpcenv->has_superuser_anywhere($userid); could actually be ordered by order of expensiveness here, but it's not=20 too important.. if ($authuser ne $userid) { my $is_superuser =3D ...; raise_perm_exc.. if !is_superuser && $rpcenv->has_superuser_anywhere(..); } or raise_perm_exc if user_mismatch_check && isnt_superuser_check && has_superuser_check; that way each check is only actually done if needed, after the previous=20 check made us go down further. the current way is just hard to parse=20 with no benefit at all. > + } > + > ($authuser, my $auth_username, my $auth_realm) =3D > PVE::AccessControl::verify_username($authuser); the whole code here is rather similar to the check in change_password,=20 have you thought about unifying them? > =20 > diff --git a/src/PVE/RPCEnvironment.pm b/src/PVE/RPCEnvironment.pm > index 4c55b25..5bcb4ba 100644 > --- a/src/PVE/RPCEnvironment.pm > +++ b/src/PVE/RPCEnvironment.pm > @@ -479,6 +479,21 @@ sub check_api2_permissions { > raise_perm_exc(); > } > =20 > +sub has_superuser_anywhere { > + my ($self, $username) =3D @_; > + > + return 1 if $username eq 'root@pam'; > + > + # get all ACL paths from config and check for SU privilege > + my $acls =3D $self->{user_cfg}->{acl}; > + my @acl_paths =3D keys(%$acls); > + @acl_paths =3D ['/'] if !@acl_paths; > + foreach my $path (@acl_paths) { > + return 1 if $self->check($username, $path, ['SuperUser'], 1); > + } > + return 0; > +} this is basically a reduced $rpcenv->get_effective_permissions with=20 early abort. some possible options: - extend it (add a '$needle' parameter, early return 1 if any path=20 matches that check) - just use it (and drop the early abort) - factor out the "get all ACL paths" part for re-using else we risk missing this helper here if we ever add another layer of=20 indirection for ACL path resolution, like we currently have for pools.. > + > sub log_cluster_msg { > my ($self, $pri, $user, $msg) =3D @_; > =20 > --=20 > 2.30.2 >=20 >=20