X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FCatalyst%2FPlugin%2FSession.pm;h=d1ab3ac21a4592e754b5396b0166f9614e33584d;hb=836b0a11e79fa4bae9dd5e72f5a6f9222b40edc9;hp=49da39e7d08bce782c3c9e2a34ef90fdad54888e;hpb=b7acf64e9edae761ba96302faee619b79c859d95;p=catagits%2FCatalyst-Plugin-Session.git diff --git a/lib/Catalyst/Plugin/Session.pm b/lib/Catalyst/Plugin/Session.pm index 49da39e..d1ab3ac 100644 --- a/lib/Catalyst/Plugin/Session.pm +++ b/lib/Catalyst/Plugin/Session.pm @@ -1,26 +1,54 @@ #!/usr/bin/perl package Catalyst::Plugin::Session; -use base qw/Class::Accessor::Fast/; -use strict; -use warnings; - -use NEXT; +use Moose; +with 'MooseX::Emulate::Class::Accessor::Fast'; +use MRO::Compat; use Catalyst::Exception (); use Digest (); use overload (); - -our $VERSION = "0.02"; - -BEGIN { - __PACKAGE__->mk_accessors(qw/_sessionid _session session_delete_reason/); +use Object::Signature (); +use Carp; + +use namespace::clean -except => 'meta'; + +our $VERSION = '0.28'; +$VERSION = eval $VERSION; + +my @session_data_accessors; # used in delete_session + +__PACKAGE__->mk_accessors( + "_session_delete_reason", + @session_data_accessors = qw/ + _sessionid + _session + _session_expires + _extended_session_expires + _session_data_sig + _flash + _flash_keep_keys + _flash_key_hashes + _tried_loading_session_id + _tried_loading_session_data + _tried_loading_session_expires + _tried_loading_flash_data + / +); + +sub _session_plugin_config { + my $c = shift; + # FIXME - Start warning once all the state/store modules have also been updated. + #$c->log->warn("Deprecated 'session' config key used, please use the key 'Plugin::Session' instead") + # if exists $c->config->{session} + #$c->config->{'Plugin::Session'} ||= delete($c->config->{session}) || {}; + $c->config->{'Plugin::Session'} ||= $c->config->{session} || {}; } sub setup { my $c = shift; - $c->NEXT::setup(@_); + $c->maybe::next::method(@_); $c->check_session_plugin_requirements; $c->setup_session; @@ -46,137 +74,408 @@ sub check_session_plugin_requirements { sub setup_session { my $c = shift; - my $cfg = ( $c->config->{session} ||= {} ); + my $cfg = $c->_session_plugin_config; %$cfg = ( expires => 7200, - verify_address => 1, + verify_address => 0, + verify_user_agent => 0, %$cfg, ); - $c->NEXT::setup_session(); + $c->maybe::next::method(); } -sub finalize { +sub prepare_action { my $c = shift; - if ( my $session_data = $c->_session ) { + $c->maybe::next::method(@_); - # all sessions are extended at the end of the request - my $now = time; - @{ $session_data }{qw/__updated __expires/} = - ( $now, $c->config->{session}{expires} + $now ); - $c->store_session_data( $c->sessionid, $session_data ); + if ( $c->_session_plugin_config->{flash_to_stash} + and $c->sessionid + and my $flash_data = $c->flash ) + { + @{ $c->stash }{ keys %$flash_data } = values %$flash_data; } +} - $c->NEXT::finalize(@_); +sub finalize_headers { + my $c = shift; + + # fix cookie before we send headers + $c->_save_session_expires; + + return $c->maybe::next::method(@_); } -sub prepare_action { +sub finalize_body { my $c = shift; - $c->_load_session; + # We have to finalize our session *before* $c->engine->finalize_xxx is called, + # because we do not want to send the HTTP response before the session is stored/committed to + # the session database (or whatever Session::Store you use). + $c->finalize_session; - $c->NEXT::prepare_action(@_); + return $c->maybe::next::method(@_); } -sub _load_session { +sub finalize_session { my $c = shift; - if ( my $sid = $c->sessionid ) { - no warnings 'uninitialized'; # ne __address + $c->maybe::next::method(@_); - my $session_data = $c->_session || $c->_session( $c->get_session_data($sid) ); - if ( !$session_data or $session_data->{__expires} < time ) { + $c->_save_session_id; + $c->_save_session; + $c->_save_flash; - # session expired - $c->log->debug("Deleting session $sid (expired)") if $c->debug; - $c->delete_session("session expired"); - } - elsif ($c->config->{session}{verify_address} - && $session_data->{__address} ne $c->request->address ) + $c->_clear_session_instance_data; +} + +sub _save_session_id { + my $c = shift; + + # we already called set when allocating + # no need to tell the state plugins anything new +} + +sub _save_session_expires { + my $c = shift; + + if ( defined($c->_session_expires) ) { + my $expires = $c->session_expires; # force extension + + my $sid = $c->sessionid; + $c->store_session_data( "expires:$sid" => $expires ); + } +} + +sub _save_session { + my $c = shift; + + if ( my $session_data = $c->_session ) { + + no warnings 'uninitialized'; + if ( Object::Signature::signature($session_data) ne + $c->_session_data_sig ) { - $c->log->warn( - "Deleting session $sid due to address mismatch (" - . $session_data->{__address} . " != " - . $c->request->address . ")", - ); - $c->delete_session("address mismatch"); + $session_data->{__updated} = time(); + my $sid = $c->sessionid; + $c->store_session_data( "session:$sid" => $session_data ); + } + } +} + +sub _save_flash { + my $c = shift; + + if ( my $flash_data = $c->_flash ) { + + my $hashes = $c->_flash_key_hashes || {}; + my $keep = $c->_flash_keep_keys || {}; + foreach my $key ( keys %$hashes ) { + if ( !exists $keep->{$key} and Object::Signature::signature( \$flash_data->{$key} ) eq $hashes->{$key} ) { + delete $flash_data->{$key}; + } + } + + my $sid = $c->sessionid; + + my $session_data = $c->_session; + if (%$flash_data) { + $session_data->{__flash} = $flash_data; } else { + delete $session_data->{__flash}; + } + $c->_session($session_data); + $c->_save_session; + } +} + +sub _load_session_expires { + my $c = shift; + return $c->_session_expires if $c->_tried_loading_session_expires; + $c->_tried_loading_session_expires(1); + + if ( my $sid = $c->sessionid ) { + my $expires = $c->get_session_data("expires:$sid") || 0; + + if ( $expires >= time() ) { + $c->_session_expires( $expires ); + return $expires; + } else { + $c->delete_session( "session expired" ); + return 0; + } + } + + return; +} + +sub _load_session { + my $c = shift; + return $c->_session if $c->_tried_loading_session_data; + $c->_tried_loading_session_data(1); + + if ( my $sid = $c->sessionid ) { + if ( $c->_load_session_expires ) { # > 0 + + my $session_data = $c->get_session_data("session:$sid") || return; + $c->_session($session_data); + + no warnings 'uninitialized'; # ne __address + if ( $c->_session_plugin_config->{verify_address} + && $session_data->{__address} ne $c->request->address ) + { + $c->log->warn( + "Deleting session $sid due to address mismatch (" + . $session_data->{__address} . " != " + . $c->request->address . ")" + ); + $c->delete_session("address mismatch"); + return; + } + if ( $c->_session_plugin_config->{verify_user_agent} + && $session_data->{__user_agent} ne $c->request->user_agent ) + { + $c->log->warn( + "Deleting session $sid due to user agent mismatch (" + . $session_data->{__user_agent} . " != " + . $c->request->user_agent . ")" + ); + $c->delete_session("user agent mismatch"); + return; + } + $c->log->debug(qq/Restored session "$sid"/) if $c->debug; + $c->_session_data_sig( Object::Signature::signature($session_data) ) if $session_data; + $c->_expire_session_keys; + + return $session_data; } + } + + return; +} + +sub _load_flash { + my $c = shift; + return $c->_flash if $c->_tried_loading_flash_data; + $c->_tried_loading_flash_data(1); + + if ( my $sid = $c->sessionid ) { + + my $session_data = $c->session; + $c->_flash($session_data->{__flash}); - $c->_expire_ession_keys; + if ( my $flash_data = $c->_flash ) + { + $c->_flash_key_hashes({ map { $_ => Object::Signature::signature( \$flash_data->{$_} ) } keys %$flash_data }); + return $flash_data; + } } + + return; } -sub _expire_ession_keys { +sub _expire_session_keys { my ( $c, $data ) = @_; my $now = time; - my $expiry = ($data || $c->_session || {})->{__expire_keys} || {}; - foreach my $key (grep { $expiry->{$_} < $now } keys %$expiry ) { + my $expire_times = ( $data || $c->_session || {} )->{__expire_keys} || {}; + foreach my $key ( grep { $expire_times->{$_} < $now } keys %$expire_times ) { delete $c->_session->{$key}; - delete $expiry->{$key}; + delete $expire_times->{$key}; } } +sub _clear_session_instance_data { + my $c = shift; + $c->$_(undef) for @session_data_accessors; + $c->maybe::next::method(@_); # allow other plugins to hook in on this +} + +sub change_session_id { + my $c = shift; + + my $sessiondata = $c->session; + my $oldsid = $c->sessionid; + my $newsid = $c->create_session_id; + + if ($oldsid) { + $c->log->debug(qq/change_sessid: deleting session data from "$oldsid"/) if $c->debug; + $c->delete_session_data("${_}:${oldsid}") for qw/session expires flash/; + } + + $c->log->debug(qq/change_sessid: storing session data to "$newsid"/) if $c->debug; + $c->store_session_data( "session:$newsid" => $sessiondata ); + + return $newsid; +} + sub delete_session { my ( $c, $msg ) = @_; + $c->log->debug("Deleting session" . ( defined($msg) ? "($msg)" : '(no reason given)') ) if $c->debug; + # delete the session data - my $sid = $c->sessionid; - $c->delete_session_data($sid); + if ( my $sid = $c->sessionid ) { + $c->delete_session_data("${_}:${sid}") for qw/session expires flash/; + $c->delete_session_id($sid); + } # reset the values in the context object - $c->_session(undef); - $c->_sessionid(undef); - $c->session_delete_reason($msg); + # see the BEGIN block + $c->_clear_session_instance_data; + + $c->_session_delete_reason($msg); +} + +sub session_delete_reason { + my $c = shift; + + $c->session_is_valid; # check that it was loaded + + $c->_session_delete_reason(@_); +} + +sub session_expires { + my $c = shift; + + if ( defined( my $expires = $c->_extended_session_expires ) ) { + return $expires; + } elsif ( defined( $expires = $c->_load_session_expires ) ) { + return $c->extend_session_expires( $expires ); + } else { + return 0; + } +} + +sub extend_session_expires { + my ( $c, $expires ) = @_; + $c->_extended_session_expires( my $updated = $c->calculate_extended_session_expires( $expires ) ); + $c->extend_session_id( $c->sessionid, $updated ); + return $updated; +} + +sub calculate_initial_session_expires { + my $c = shift; + return ( time() + $c->_session_plugin_config->{expires} ); +} + +sub calculate_extended_session_expires { + my ( $c, $prev ) = @_; + $c->calculate_initial_session_expires; +} + +sub reset_session_expires { + my ( $c, $sid ) = @_; + + my $exp = $c->calculate_initial_session_expires; + $c->_session_expires( $exp ); + $c->_extended_session_expires( $exp ); + $exp; } sub sessionid { - my $c = shift; + my $c = shift; - if ( @_ ) { - if ( $c->validate_session_id( my $sid = shift ) ) { - return $c->_sessionid( $sid ); - } else { - my $err = "Tried to set invalid session ID '$sid'"; - $c->log->error( $err ); - Catalyst::Exception->throw( $err ); - } - } + return $c->_sessionid || $c->_load_sessionid; +} - return $c->_sessionid; +sub _load_sessionid { + my $c = shift; + return if $c->_tried_loading_session_id; + $c->_tried_loading_session_id(1); + + if ( defined( my $sid = $c->get_session_id ) ) { + if ( $c->validate_session_id($sid) ) { + # temporarily set the inner key, so that validation will work + $c->_sessionid($sid); + return $sid; + } else { + my $err = "Tried to set invalid session ID '$sid'"; + $c->log->error($err); + Catalyst::Exception->throw($err); + } + } + + return; +} + +sub session_is_valid { + my $c = shift; + + # force a check for expiry, but also __address, etc + if ( $c->_load_session ) { + return 1; + } else { + return; + } } sub validate_session_id { - my ( $c, $sid ) = @_; + my ( $c, $sid ) = @_; - $sid =~ /^[a-f\d]+$/i; + $sid and $sid =~ /^[a-f\d]+$/i; } sub session { my $c = shift; - $c->_session || do { - my $sid = $c->generate_session_id; - $c->sessionid($sid); + $c->_session || $c->_load_session || do { + $c->create_session_id_if_needed; + $c->initialize_session_data; + }; +} - $c->log->debug(qq/Created session "$sid"/) if $c->debug; +sub keep_flash { + my ( $c, @keys ) = @_; + my $href = $c->_flash_keep_keys || $c->_flash_keep_keys({}); + (@{$href}{@keys}) = ((undef) x @keys); +} + +sub _flash_data { + my $c = shift; + $c->_flash || $c->_load_flash || do { + $c->create_session_id_if_needed; + $c->_flash( {} ); + }; +} + +sub _set_flash { + my $c = shift; + if (@_) { + my $items = @_ > 1 ? {@_} : $_[0]; + croak('flash takes a hash or hashref') unless ref $items; + @{ $c->_flash }{ keys %$items } = values %$items; + } +} + +sub flash { + my $c = shift; + $c->_flash_data; + $c->_set_flash(@_); + return $c->_flash; +} - $c->initialize_session_data; - }; +sub clear_flash { + my $c = shift; + + #$c->delete_session_data("flash:" . $c->sessionid); # should this be in here? or delayed till finalization? + $c->_flash_key_hashes({}); + $c->_flash_keep_keys({}); + $c->_flash({}); } sub session_expire_key { my ( $c, %keys ) = @_; my $now = time; - @{ $c->session->{__expire_keys} }{keys %keys} = map { $now + $_ } values %keys; + @{ $c->session->{__expire_keys} }{ keys %keys } = + map { $now + $_ } values %keys; } sub initialize_session_data { @@ -184,17 +483,23 @@ sub initialize_session_data { my $now = time; - return $c->_session({ - __created => $now, - __updated => $now, - __expires => $now + $c->config->{session}{expires}, - - ( - $c->config->{session}{verify_address} - ? ( __address => $c->request->address ) - : () - ), - }); + return $c->_session( + { + __created => $now, + __updated => $now, + + ( + $c->_session_plugin_config->{verify_address} + ? ( __address => $c->request->address||'' ) + : () + ), + ( + $c->_session_plugin_config->{verify_user_agent} + ? ( __user_agent => $c->request->user_agent||'' ) + : () + ), + } + ); } sub generate_session_id { @@ -205,6 +510,25 @@ sub generate_session_id { return $digest->hexdigest; } +sub create_session_id_if_needed { + my $c = shift; + $c->create_session_id unless $c->sessionid; +} + +sub create_session_id { + my $c = shift; + + my $sid = $c->generate_session_id; + + $c->log->debug(qq/Created session "$sid"/) if $c->debug; + + $c->_sessionid($sid); + $c->reset_session_expires; + $c->set_session_id($sid); + + return $sid; +} + my $counter; sub session_hash_seed { @@ -217,17 +541,16 @@ my $usable; sub _find_digest () { unless ($usable) { - foreach my $alg (qw/SHA-1 MD5 SHA-256/) { - eval { - my $obj = Digest->new($alg); + foreach my $alg (qw/SHA-1 SHA-256 MD5/) { + if ( eval { Digest->new($alg) } ) { $usable = $alg; - return $obj; - }; + last; + } } - $usable - or Catalyst::Exception->throw( + Catalyst::Exception->throw( "Could not find a suitable Digest module. Please install " - . "Digest::SHA1, Digest::SHA, or Digest::MD5" ); + . "Digest::SHA1, Digest::SHA, or Digest::MD5" ) + unless $usable; } return Digest->new($usable); @@ -237,7 +560,7 @@ sub dump_these { my $c = shift; ( - $c->NEXT::dump_these(), + $c->maybe::next::method(), $c->sessionid ? ( [ "Session ID" => $c->sessionid ], [ Session => $c->session ], ) @@ -245,6 +568,12 @@ sub dump_these { ); } + +sub get_session_id { shift->maybe::next::method(@_) } +sub set_session_id { shift->maybe::next::method(@_) } +sub delete_session_id { shift->maybe::next::method(@_) } +sub extend_session_id { shift->maybe::next::method(@_) } + __PACKAGE__; __END__ @@ -253,8 +582,7 @@ __END__ =head1 NAME -Catalyst::Plugin::Session - Generic Session plugin - ties together server side -storage and client side state required to maintain session data. +Catalyst::Plugin::Session - Generic Session plugin - ties together server side storage and client side state required to maintain session data. =head1 SYNOPSIS @@ -266,11 +594,11 @@ storage and client side state required to maintain session data. Session::State::Cookie /; - # you can replace Store::FastMmap with Store::File - both have sensible - # default configurations (see their docs for details) + # you can replace Store::FastMmap with Store::File - both have sensible + # default configurations (see their docs for details) - # more complicated backends are available for other scenarios (DBI storage, - # etc) + # more complicated backends are available for other scenarios (DBI storage, + # etc) # after you've loaded the plugins you can save session data @@ -315,7 +643,7 @@ made by the same client. This plugin links the two pieces together. -=head1 RECCOMENDED BACKENDS +=head1 RECOMENDED BACKENDS =over 4 @@ -350,6 +678,69 @@ requests. This method will automatically create a new session and session ID if none exists. +=item session_expires + +=item session_expires $reset + +This method returns the time when the current session will expire, or 0 if +there is no current session. If there is a session and it already expired, it +will delete the session and return 0 as well. + +If the C<$reset> parameter is true, and there is a session ID the expiry time +will be reset to the current time plus the time to live (see +L). This is used when creating a new session. + +=item flash + +This is like Ruby on Rails' flash data structure. Think of it as a stash that +lasts for longer than one request, letting you redirect instead of forward. + +The flash data will be cleaned up only on requests on which actually use +$c->flash (thus allowing multiple redirections), and the policy is to delete +all the keys which haven't changed since the flash data was loaded at the end +of every request. + + sub moose : Local { + my ( $self, $c ) = @_; + + $c->flash->{beans} = 10; + $c->response->redirect( $c->uri_for("foo") ); + } + + sub foo : Local { + my ( $self, $c ) = @_; + + my $value = $c->flash->{beans}; + + # ... + + $c->response->redirect( $c->uri_for("bar") ); + } + + sub bar : Local { + my ( $self, $c ) = @_; + + if ( exists $c->flash->{beans} ) { # false + + } + } + +=item clear_flash + +Zap all the keys in the flash regardless of their current state. + +=item keep_flash @keys + +If you want to keep a flash key for the next request too, even if it hasn't +changed, call C and pass in the keys as arguments. + +=item delete_session REASON + +This method is used to invalidate a session. It takes an optional parameter +which will be saved in C if provided. + +NOTE: This method will B delete your flash data. + =item session_delete_reason This accessor contains a string with the reason a session was deleted. Possible @@ -374,7 +765,7 @@ expiry time for the whole session). For example: - __PACKAGE__->config->{session}{expires} = 1000000000000; # forever + __PACKAGE__->config('Plugin::Session' => { expires => 1000000000000 }); # forever # later @@ -385,9 +776,34 @@ an hour. Note that these values are not auto extended. +=item change_session_id + +By calling this method you can force a session id change while keeping all +session data. This method might come handy when you are paranoid about some +advanced variations of session fixation attack. + +If you want to prevent this session fixation scenario: + + 0) let us have WebApp with anonymous and authenticated parts + 1) a hacker goes to vulnerable WebApp and gets a real sessionid, + just by browsing anonymous part of WebApp + 2) the hacker inserts (somehow) this values into a cookie in victim's browser + 3) after the victim logs into WebApp the hacker can enter his/her session + +you should call change_session_id in your login controller like this: + + if ($c->authenticate( { username => $user, password => $pass } )) { + # login OK + $c->change_session_id; + ... + } else { + # login FAILED + ... + } + =back -=item INTERNAL METHODS +=head1 INTERNAL METHODS =over 4 @@ -403,43 +819,36 @@ application. =item setup_session -This method populates C<< $c->config->{session} >> with the default values +This method populates C<< $c->config('Plugin::Session') >> with the default values listed in L. =item prepare_action -This methoid is extended, and will restore session data and check it for -validity if a session id is defined. It assumes that the State plugin will -populate the C key beforehand. +This method is extended. -=item finalize +Its only effect is if the (off by default) C configuration +parameter is on - then it will copy the contents of the flash to the stash at +prepare time. -This method is extended and will extend the expiry time, as well as persist the -session data if a session exists. +=item finalize_headers -=item delete_session REASON +This method is extended and will extend the expiry time before sending +the response. -This method is used to invalidate a session. It takes an optional parameter -which will be saved in C if provided. +=item finalize_body + +This method is extended and will call finalize_session before the other +finalize_body methods run. Here we persist the session data if a session exists. =item initialize_session_data This method will initialize the internal structure of the session, and is called by the C method if appropriate. -=item generate_session_id - -This method will return a string that can be used as a session ID. It is -supposed to be a reasonably random string with enough bits to prevent -collision. It basically takes C and hashes it using SHA-1, -MD5 or SHA-256, depending on the availibility of these modules. - -=item session_hash_seed +=item create_session_id -This method is actually rather internal to generate_session_id, but should be -overridable in case you want to provide more random data. - -Currently it returns a concatenated string which contains: +Creates a new session ID using C if there is no session ID +yet. =item validate_session_id SID @@ -448,31 +857,35 @@ Make sure a session ID is of the right format. This currently ensures that the session ID string is any amount of case insensitive hexadecimal characters. -=over 4 +=item generate_session_id -=item * +This method will return a string that can be used as a session ID. It is +supposed to be a reasonably random string with enough bits to prevent +collision. It basically takes C and hashes it using SHA-1, +MD5 or SHA-256, depending on the availability of these modules. -A counter +=item session_hash_seed -=item * +This method is actually rather internal to generate_session_id, but should be +overridable in case you want to provide more random data. -The current time +Currently it returns a concatenated string which contains: -=item * +=over 4 -One value from C. +=item * A counter -=item * +=item * The current time -The stringified value of a newly allocated hash reference +=item * One value from C. -=item * +=item * The stringified value of a newly allocated hash reference -The stringified value of the Catalyst context object +=item * The stringified value of the Catalyst context object =back -In the hopes that those combined values are entropic enough for most uses. If +in the hopes that those combined values are entropic enough for most uses. If this is not the case you can replace C with e.g. sub session_hash_seed { @@ -494,11 +907,38 @@ Or even more directly, replace C: Also have a look at L and the various openssl bindings - these modules provide APIs for cryptographically secure random data. +=item finalize_session + +Clean up the session during C. + +This clears the various accessors after saving to the store. + =item dump_these See L - ammends the session data structure to the list of dumped objects if session ID is defined. + +=item calculate_extended_session_expires + +=item calculate_initial_session_expires + +=item create_session_id_if_needed + +=item delete_session_id + +=item extend_session_expires + +=item extend_session_id + +=item get_session_id + +=item reset_session_expires + +=item session_is_valid + +=item set_session_id + =back =head1 USING SESSIONS DURING PREPARE @@ -510,25 +950,25 @@ State plugins must set $c->session ID before C, and during C L will actually load the data from the store. - sub prepare_action { - my $c = shift; + sub prepare_action { + my $c = shift; - # don't touch $c->session yet! + # don't touch $c->session yet! - $c->NEXT::prepare_action( @_ ); + $c->NEXT::prepare_action( @_ ); - $c->session; # this is OK - $c->sessionid; # this is also OK - } + $c->session; # this is OK + $c->sessionid; # this is also OK + } =head1 CONFIGURATION - $c->config->{session} = { + $c->config('Plugin::Session' => { expires => 1234, - }; + }); All configuation parameters are provided in a hash reference under the -C key in the configuration hash. +C key in the configuration hash. =over 4 @@ -542,6 +982,22 @@ hours). When true, C<<$c->request->address>> will be checked at prepare time. If it is not the same as the address that initiated the session, the session is deleted. +Defaults to false. + +=item verify_user_agent + +When true, C<<$c->request->user_agent>> will be checked at prepare time. If it +is not the same as the user agent that initiated the session, the session is +deleted. + +Defaults to false. + +=item flash_to_stash + +This option makes it easier to have actions behave the same whether they were +forwarded to or redirected to. On prepare time it copies the contents of +C (if any) to the stash. + =back =head1 SPECIAL KEYS @@ -553,14 +1009,11 @@ are automatically set: =item __expires -A timestamp whose value is the last second when the session is still valid. If -a session is restored, and __expires is less than the current time, the session -is deleted. +This key no longer exists. Use C instead. =item __updated -The last time a session was saved. This is the value of -C<< $c->session->{__expires} - $c->config->session->{expires} >>. +The last time a session was saved to the store. =item __created @@ -571,10 +1024,17 @@ The time when the session was first created. The value of C<< $c->request->address >> at the time the session was created. This value is only populated if C is true in the configuration. +=item __user_agent + +The value of C<< $c->request->user_agent >> at the time the session was created. +This value is only populated if C is true in the configuration. + =back =head1 CAVEATS +=head2 Round the Robin Proxies + C could make your site inaccessible to users who are behind load balanced proxies. Some ISPs may give a different IP to each request by the same client due to this type of proxying. If addresses are verified these @@ -583,30 +1043,78 @@ users' sessions cannot persist. To let these users access your site you can either disable address verification as a whole, or provide a checkbox in the login dialog that tells the server that it's OK for the address of the client to change. When the server sees that -this box is checked it should delete the C<__address> sepcial key from the +this box is checked it should delete the C<__address> special key from the session hash when the hash is first created. -=head1 AUTHORS +=head2 Race Conditions + +In this day and age where cleaning detergents and Dutch football (not the +American kind) teams roam the plains in great numbers, requests may happen +simultaneously. This means that there is some risk of session data being +overwritten, like this: =over 4 -=item Andy Grundman +=item 1. + +request a starts, request b starts, with the same session ID + +=item 2. + +session data is loaded in request a + +=item 3. + +session data is loaded in request b -=item Christian Hansen +=item 4. -=item Yuval Kogman, C (current maintainer) +session data is changed in request a -=item Sebastian Riedel +=item 5. + +request a finishes, session data is updated and written to store + +=item 6. + +request b finishes, session data is updated and written to store, overwriting +changes by request a =back +If this is a concern in your application, a soon-to-be-developed locking +solution is the only safe way to go. This will have a bigger overhead. + +For applications where any given user is only making one request at a time this +plugin should be safe enough. + +=head1 AUTHORS + +Andy Grundman + +Christian Hansen + +Yuval Kogman, C + +Sebastian Riedel + +Tomas Doran (t0m) C (current maintainer) + +Sergio Salvi + +kmx C + +Florian Ragwitz (rafl) C + +Kent Fredric (kentnl) + And countless other contributers from #catalyst. Thanks guys! =head1 COPYRIGHT & LICENSE - Copyright (c) 2005 the aforementioned authors. All rights - reserved. This program is free software; you can redistribute - it and/or modify it under the same terms as Perl itself. + Copyright (c) 2005 the aforementioned authors. All rights + reserved. This program is free software; you can redistribute + it and/or modify it under the same terms as Perl itself. =cut