[pve-devel] [access-contorl] fix #2947 login name for the LDAP/AD realm can be case-insensitive

[Thomas Lamprecht]

off-topic: Please switch over your mails "To" address from the old
<pve-devel at pve.proxmox.com> to the new <pve-devel at lists.proxmox.com>, thank you!

On 8/28/20 1:19 PM, Wolfgang Link wrote:
> This is an optional for LDAP and AD realm.
> The default behavior is case-sensitive.
> 

looks good in general, thanks!
two nits and and additional place where we may want to use the new helper
below.

> Signed-off-by: Wolfgang Link <w.link at proxmox.com>
> ---
>  PVE/API2/AccessControl.pm | 20 ++++++++++++++++++++
>  PVE/Auth/LDAP.pm          |  7 +++++++
>  2 files changed, 27 insertions(+)
> 
> diff --git a/PVE/API2/AccessControl.pm b/PVE/API2/AccessControl.pm
> index fd27786..4b4d0be 100644
> --- a/PVE/API2/AccessControl.pm
> +++ b/PVE/API2/AccessControl.pm
> @@ -226,6 +226,25 @@ __PACKAGE__->register_method ({
>      returns => { type => "null" },
>      code => sub { return undef; }});
>  
> +sub lookup_username {
> +    my ($username) = @_;
> +
> +    $username =~ /@(.+)/;
> +
> +    my $realm = $1;
> +    my $domain_cfg = cfs_read_file("domains.cfg");
> +    my $casesensitive = $domain_cfg->{ids}->{$realm}->{casesensitive} // 1;
> +    my $usercfg = cfs_read_file('user.cfg');
> +
> +    if ($casesensitive == 0) {

nit: we normally rather use `if (!$casesensitive)`

> +	foreach my $user_name (keys %{$usercfg->{users}}) {
> +	    return $user_name if lc $username eq lc $user_name;
> +	}

above is fine, but if we'd use the built-in grep we could also easily die
on multiple matches, for example, something below (untested):

my @matches = grep { lc $username eq lc $_ } @{keys %{$usercfg->{users}}};

die "ambiguous case insensitive match of username '$username', cannot safely grant access!\n"
    if scalar @matches > 1;

return $matches[1];


And we then actually want to use this method also in the API call for adding
new users, to ensure an admin do not accidentally adds the case-sensitive same
user multiple times.

> +    }
> +
> +    return $username;
> +};
> +
>  __PACKAGE__->register_method ({
>      name => 'create_ticket',
>      path => 'ticket',
> @@ -292,6 +311,7 @@ __PACKAGE__->register_method ({
>  	my $username = $param->{username};
>  	$username .= "\@$param->{realm}" if $param->{realm};
>  
> +	$username = lookup_username($username);
>  	my $rpcenv = PVE::RPCEnvironment::get();
>  
>  	my $res;
> diff --git a/PVE/Auth/LDAP.pm b/PVE/Auth/LDAP.pm
> index 09b2202..75cce0f 100755
> --- a/PVE/Auth/LDAP.pm
> +++ b/PVE/Auth/LDAP.pm
> @@ -129,6 +129,12 @@ sub properties {
>  	    optional => 1,
>  	    default => 'ldap',
>  	},
> +        casesensitive => {


can we please use 'case-sensitive' here, makes it way easier to read.
(and we (Wolfgang B and me) want to go away from using underscore as
separator for API/ABI properties or parameters :))

> +	    description => "username is case-sensitive",
> +	    type => 'boolean',
> +	    optional => 1,
> +	    default => 1,
> +	}
>      };
>  }
>  
> @@ -159,6 +165,7 @@ sub options {
>  	group_classes => { optional => 1 },
>  	'sync-defaults-options' => { optional => 1 },
>  	mode => { optional => 1 },
> +	casesensitive => { optional => 1 },
>      };
>  }
>  
>