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Diffstat (limited to 'perl/lib/Wallet/ACL/Nested.pm')
-rw-r--r-- | perl/lib/Wallet/ACL/Nested.pm | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/perl/lib/Wallet/ACL/Nested.pm b/perl/lib/Wallet/ACL/Nested.pm new file mode 100644 index 0000000..945d881 --- /dev/null +++ b/perl/lib/Wallet/ACL/Nested.pm @@ -0,0 +1,193 @@ +# Wallet::ACL::Nested - ACL class for nesting ACLs +# +# Written by Jon Robertson <jonrober@stanford.edu> +# Copyright 2015 +# The Board of Trustees of the Leland Stanford Junior University +# +# See LICENSE for licensing terms. + +############################################################################## +# Modules and declarations +############################################################################## + +package Wallet::ACL::Nested; +require 5.006; + +use strict; +use warnings; +use vars qw($VERSION @ISA); + +use Wallet::ACL::Base; + +@ISA = qw(Wallet::ACL::Base); + +# This version should be increased on any code change to this module. Always +# use two digits for the minor version with a leading zero if necessary so +# that it will sort properly. +$VERSION = '0.01'; + +############################################################################## +# Interface +############################################################################## + +# Creates a new persistant verifier, taking a database handle to use for +# syntax check validation. +sub new { + my $type = shift; + my ($name, $schema) = @_; + my $self = { + schema => $schema, + expanded => {}, + }; + bless ($self, $type); + return $self; +} + +# Name checking requires checking that there's an existing ACL already by +# this name. Try to create the ACL object and use that to determine. +sub syntax_check { + my ($self, $group) = @_; + + my $acl; + eval { $acl = Wallet::ACL->new ($group, $self->{schema}) }; + return 0 if $@; + return 0 unless $acl; + return 1; +} + +# For checking a nested ACL, we need to expand each entry and then check +# that entry. We also want to keep track of things already checked in order +# to avoid any loops. +sub check { + my ($self, $principal, $group) = @_; + unless ($principal) { + $self->error ('no principal specified'); + return; + } + unless ($group) { + $self->error ('malformed nested ACL'); + return; + } + + # Make an ACL object just so that we can use it to drop back into the + # normal ACL validation after we have expanded the nesting. + my $acl; + eval { $acl = Wallet::ACL->new ($group, $self->{schema}) }; + + # Get the list of all nested acl entries within this entry, and use it + # to go through each entry and decide if the given acl has access. + my @members = $self->get_membership ($group); + for my $entry (@members) { + my ($type, $name) = @{ $entry }; + my $result = $acl->check_line ($principal, $type, $name); + return 1 if $result; + } + return 0; +} + +# Get the membership of a group recursively. The final result will be a list +# of arrayrefs like that from Wallet::ACL->list, but expanded for full +# membership. +sub get_membership { + my ($self, $group) = @_; + + # Get the list of members for this nested acl. Consider any missing acls + # as empty. + my $schema = $self->{schema}; + my @members; + eval { + my $acl = Wallet::ACL->new ($group, $schema); + @members = $acl->list; + }; + + # Now go through and expand any other nested groups into their own + # memberships. + my @expanded; + for my $entry (@members) { + my ($type, $name) = @{ $entry }; + if ($type eq 'nested') { + + # Keep track of things we've already expanded and don't look them + # up again. + next if exists $self->{expanded}{$name}; + $self->{expanded}{$name} = 1; + push (@expanded, $self->get_membership ($name)); + + } else { + push (@expanded, $entry); + } + } + + return @expanded; +} + +1; +__END__ + +############################################################################## +# Documentation +############################################################################## + +=for stopwords +ACL Allbery verifier verifiers + +=head1 NAME + +Wallet::ACL::Base - Generic parent class for wallet ACL verifiers + +=head1 SYNOPSIS + + package Wallet::ACL::Simple + @ISA = qw(Wallet::ACL::Base); + sub check { + my ($self, $principal, $acl) = @_; + return ($principal eq $acl) ? 1 : 0; + } + +=head1 DESCRIPTION + +Wallet::ACL::Base is the generic parent class for wallet ACL verifiers. +It provides default functions and behavior and all ACL verifiers should +inherit from it. It is not used directly. + +=head1 METHODS + +=over 4 + +=item new() + +Creates a new ACL verifier. The generic function provided here just +creates and blesses an object. + +=item check(PRINCIPAL, ACL) + +This method should always be overridden by child classes. The default +implementation just declines all access. + +=item error([ERROR ...]) + +Returns the error of the last failing operation or undef if no operations +have failed. Callers should call this function to get the error message +after an undef return from any other instance method. + +For the convenience of child classes, this method can also be called with +one or more error strings. If so, those strings are concatenated +together, trailing newlines are removed, any text of the form S<C< at \S+ +line \d+\.?>> at the end of the message is stripped off, and the result is +stored as the error. Only child classes should call this method with an +error string. + +=back + +=head1 SEE ALSO + +Wallet::ACL(3), wallet-backend(8) + +This module is part of the wallet system. The current version is +available from L<http://www.eyrie.org/~eagle/software/wallet/>. + +=head1 AUTHOR + +Russ Allbery <eagle@eyrie.org> + +=cut |