From 4c1b8033b07680fc1ee1cdd4f515ca89545b22c4 Mon Sep 17 00:00:00 2001
From: Marius Gavrilescu <marius@ieval.ro>
Date: Sun, 1 Mar 2015 13:13:53 +0200
Subject: [PATCH] Add authentication cache

---
 Makefile.PL                          |  3 ++-
 lib/Plack/Middleware/Auth/Complex.pm | 26 ++++++++++++++++++++++++--
 t/Plack-Middleware-Auth-Complex.t    |  9 +++++++--
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/Makefile.PL b/Makefile.PL
index 3d96b1a..21ef80a 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -21,7 +21,8 @@ WriteMakefile(
 		   DBI                               0
 		   Email::Simple                     0
 		   Email::Sender::Simple             0
-		   Plack::Request                    0/,
+		   Plack::Request                    0
+		   Tie::Hash::Expire                 0/,
 	},
 	META_MERGE         => {
 		dynamic_config => 0,
diff --git a/lib/Plack/Middleware/Auth/Complex.pm b/lib/Plack/Middleware/Auth/Complex.pm
index 920810c..55fc5ee 100644
--- a/lib/Plack/Middleware/Auth/Complex.pm
+++ b/lib/Plack/Middleware/Auth/Complex.pm
@@ -13,11 +13,12 @@ use Authen::Passphrase;
 use Authen::Passphrase::BlowfishCrypt;
 use Bytes::Random::Secure qw/random_bytes/;
 use DBI;
-use Digest::SHA qw/hmac_sha1_base64/;
+use Digest::SHA qw/hmac_sha1_base64 sha256/;
 use Email::Simple;
 use Email::Sender::Simple qw/sendmail/;
 use MIME::Base64 qw/decode_base64/;
 use Plack::Request;
+use Tie::Hash::Expire;
 
 sub default_opts {(
 	dbi_connect       => ['dbi:Pg:', '', ''],
@@ -26,6 +27,8 @@ sub default_opts {(
 	insert_user       => 'INSERT INTO users (id, passphrase, email) VALUES (?,?,?)',
 	mail_subject      => 'Password reset token',
 	realm             => 'restricted area',
+	cache_fail        => 0,
+	cache_max_age     => 5 * 60,
 	token_max_age     => 60 * 60 * 24,
 	username_regex    => qr/^\w{2,20}$/a,
 	register_url      => '/action/register',
@@ -60,9 +63,17 @@ sub get_user {
 
 sub check_passphrase {
 	my ($self, $username, $passphrase) = @_;
+	unless ($self->{cache}) {
+		tie my %cache, 'Tie::Hash::Expire', {expire_seconds => $self->{cache_max_age}};
+		$self->{cache} = \%cache;
+	}
+	my $cachekey = sha256 "$username:$passphrase";
+	return $self->{cache}{$cachekey} if exists $self->{cache}{$cachekey};
 	my $user = $self->get_user($username);
 	return 0 unless $user;
-	Authen::Passphrase->from_rfc2307($user->{passphrase})->match($passphrase)
+	my $ret = Authen::Passphrase->from_rfc2307($user->{passphrase})->match($passphrase);
+	$self->{cache}{$cachekey} = $ret if $ret || $self->{cache_fail};
+	$ret
 }
 
 sub hash_passphrase {
@@ -348,6 +359,17 @@ C<'Password reset token'>.
 
 Authentication realm. Defaults to C<'restricted area'>.
 
+=item cache_fail
+
+If true, all authentication results are cached. If false, only
+successful logins are cached. Defaults to false.
+
+=item cache_max_age
+
+Authentication cache timeout, in seconds. Authentication results are
+cached for this number of seconds to avoid expensive hashing. Defaults
+to 5 minutes.
+
 =item token_max_age
 
 Password reset token validity, in seconds. Defaults to 24 hours.
diff --git a/t/Plack-Middleware-Auth-Complex.t b/t/Plack-Middleware-Auth-Complex.t
index 956ee67..5b42232 100644
--- a/t/Plack-Middleware-Auth-Complex.t
+++ b/t/Plack-Middleware-Auth-Complex.t
@@ -30,8 +30,13 @@ sub is_http {
 
 my $create_table = 'CREATE TABLE users (id TEXT PRIMARY KEY, passphrase TEXT, email TEXT)';
 my $ac = Plack::Middleware::Auth::Complex->new({
-	dbi_connect     => ['dbi:SQLite:dbname=:memory:'],
-	post_connect_cb => sub { shift->{dbh}->do($create_table) },
+	dbi_connect       => ['dbi:SQLite:dbname=:memory:'],
+	post_connect_cb   => sub { shift->{dbh}->do($create_table) },
+	register_url      => '/register',
+	passwd_url        => '/passwd',
+	request_reset_url => '/request-reset',
+	reset_url         => '/reset',
+	cache_max_age     => 0,
 });
 
 my $app = $ac->wrap(\&app);
-- 
2.30.2