From 61456017abf30a3c00c25b53ac7ca4c8c90741eb Mon Sep 17 00:00:00 2001
From: Marius Gavrilescu <marius@ieval.ro>
Date: Sat, 15 Jul 2017 18:20:40 +0300
Subject: [PATCH] Use Data::Entropy for random numbers

---
 Makefile.PL                          |  2 +-
 lib/Plack/Middleware/Auth/Complex.pm | 29 +++++++++++++++++++++++++---
 2 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/Makefile.PL b/Makefile.PL
index 531b607..94058df 100644
--- a/Makefile.PL
+++ b/Makefile.PL
@@ -18,7 +18,7 @@ WriteMakefile(
 	PREREQ_PM         => {
 		qw/Authen::Passphrase                0
 		   Authen::Passphrase::BlowfishCrypt 0
-		   Bytes::Random::Secure             0
+		   Data::Entropy                     0
 		   DBI                               0
 		   Email::Simple                     0
 		   Email::Sender::Simple             0
diff --git a/lib/Plack/Middleware/Auth/Complex.pm b/lib/Plack/Middleware/Auth/Complex.pm
index b8e3565..59d9bc3 100644
--- a/lib/Plack/Middleware/Auth/Complex.pm
+++ b/lib/Plack/Middleware/Auth/Complex.pm
@@ -11,8 +11,10 @@ use re '/s';
 
 use Authen::Passphrase;
 use Authen::Passphrase::BlowfishCrypt;
-use Bytes::Random::Secure qw//;
-use Carp qw/croak/;
+use Data::Entropy qw/entropy_source/;
+use Data::Entropy::Source;
+use Data::Entropy::RawSource::Local;
+use Carp qw/carp croak/;
 use DBI;
 use Digest::SHA qw/hmac_sha1_base64 sha256/;
 use Email::Simple;
@@ -21,6 +23,18 @@ use MIME::Base64 qw/decode_base64/;
 use Plack::Request;
 use Tie::Hash::Expire;
 
+sub make_entropy_source {
+	if (-e '/dev/urandom') {
+		Data::Entropy::Source->new(
+			Data::Entropy::RawSource::Local->new('/dev/urandom'),
+			'sysread'
+		)
+	} else {
+		carp "/dev/urandom not found, using insecure random source\n";
+		entropy_source
+	}
+}
+
 sub default_opts {(
 	dbi_connect       => ['dbi:Pg:', '', ''],
 	select_user       => 'SELECT passphrase, email FROM users WHERE id = ?',
@@ -43,6 +57,7 @@ sub new {
 	my ($class, $opts) = @_;
 	my %self = $class->default_opts;
 	%self = (%self, %$opts);
+	$self{entropy_source} //= make_entropy_source;
 	my $self = bless \%self, $class;
 	$self
 }
@@ -100,7 +115,7 @@ sub set_passphrase {
 
 sub make_reset_hmac {
 	my ($self, $username, @data) = @_;
-	$self->{hmackey} //= Bytes::Random::Secure->new(NonBlocking => 1)->bytes(512); # uncoverable condition false
+	$self->{hmackey} //= $self->{entropy_source}->get_bits(8 * 512); # uncoverable condition false
 	my $user = $self->get_user($username);
 	my $message = join ' ', $username, $user->{passphrase}, @data;
 	hmac_sha1_base64 $message, $self->{hmackey};
@@ -332,6 +347,14 @@ This URL performs a password reset.
 Arrayref of arguments to pass to DBI->connect. Defaults to
 C<['dbi:Pg', '', '']>.
 
+=item entropy_source
+
+C<Data::Entropy::Source> object to get random numbers from. By default
+uses F</dev/urandom> via C<Data::Entropy::RawSource::Local> if
+possible, or the default entropy source otherwise. A warning is
+printed if the default entropy source is used, to supress it set this
+argument to the default entropy source.
+
 =item post_connect_cb
 
 Callback (coderef) that is called just after connecting to the
-- 
2.30.2