From 4c2f3ed6bb8863c189d60af02be78d3d969a024e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Salvador=20Fandi=C3=B1o?= <salvador.fandino@apoloai.com>
Date: Thu, 4 Jun 2026 13:48:45 +0200
Subject: [PATCH 1/2] Harden module loading

---
 MANIFEST                        |  1 +
 lib/Net/OpenSSH/ModuleLoader.pm | 15 +++++++--------
 t/module-loader.t               | 31 +++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 8 deletions(-)
 create mode 100644 t/module-loader.t

diff --git a/MANIFEST b/MANIFEST
index 7def16c..e11f0ef 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -23,6 +23,7 @@ t/test_server_key.pub
 t/test_user_key
 t/test_user_key.pub
 t/known_hosts
+t/module-loader.t
 t/quoting.t
 t/uri.t
 examples/expect.pl
diff --git a/lib/Net/OpenSSH/ModuleLoader.pm b/lib/Net/OpenSSH/ModuleLoader.pm
index 149a517..37f18c4 100644
--- a/lib/Net/OpenSSH/ModuleLoader.pm
+++ b/lib/Net/OpenSSH/ModuleLoader.pm
@@ -11,23 +11,22 @@ our @EXPORT = qw(_load_module);
 
 sub _load_module {
     my ($module, $version) = @_;
+    $module =~ /\A[A-Za-z_]\w*(?:::\w+)*\z/
+        or croak "bad Perl module name $module";
     $loaded_module{$module} ||= do {
         my $err;
         do {
             local ($@, $SIG{__DIE__});
-            my $ok = eval "require $module; 1";
+            (my $path = "$module.pm") =~ s!::!/!g;
+            my $ok = eval { require $path; 1 };
             $err = $@;
             $ok;
         } or croak "unable to load Perl module $module: $err";
     };
     if (defined $version) {
-        my $mv = do {
-            local ($@, $SIG{__DIE__});
-            eval "\$${module}::VERSION";
-        } || 0;
-	(my $mv1 = $mv) =~ s/_\d*$//;
-	croak "$module version $version required, $mv is available"
-	    if $mv1 < $version;
+        local ($@, $SIG{__DIE__});
+        eval { $module->VERSION($version); 1 }
+            or croak $@ || "$module version $version required";
     }
     1
 }
diff --git a/t/module-loader.t b/t/module-loader.t
new file mode 100644
index 0000000..6fddd9c
--- /dev/null
+++ b/t/module-loader.t
@@ -0,0 +1,31 @@
+#!/usr/bin/perl
+
+use strict;
+use warnings;
+
+use Test::More tests => 5;
+
+use Net::OpenSSH::ModuleLoader;
+
+ok(_load_module('strict'), 'loads a valid module name');
+
+eval { _load_module('strict; die "boom"') };
+like($@, qr/bad Perl module name/, 'rejects unsafe module names');
+
+eval { _load_module('strict', 999_999) };
+like($@, qr/strict version 999999 required|strict version 999999 required--this is only version/,
+     'uses standard VERSION checks for too-new requirements');
+
+{
+    package Test::Net::OpenSSH::ModuleLoader::Versioned;
+    our $VERSION = '1.02';
+}
+
+$INC{'Test/Net/OpenSSH/ModuleLoader/Versioned.pm'} = __FILE__;
+
+ok(_load_module('Test::Net::OpenSSH::ModuleLoader::Versioned', '1.01'),
+   'accepts a sufficient version');
+
+eval { _load_module('Test::Net::OpenSSH::ModuleLoader::Versioned', '1.03') };
+like($@, qr/Test::Net::OpenSSH::ModuleLoader::Versioned version 1.03 required/,
+     'rejects an insufficient version');

From 4e504a6ed3b4c3acb857702da3f0120104b20381 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Salvador=20Fandi=C3=B1o?= <salvador.fandino@apoloai.com>
Date: Thu, 4 Jun 2026 16:35:26 +0200
Subject: [PATCH 2/2] Handle undefined module names

---
 lib/Net/OpenSSH/ModuleLoader.pm | 1 +
 t/module-loader.t               | 5 ++++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/Net/OpenSSH/ModuleLoader.pm b/lib/Net/OpenSSH/ModuleLoader.pm
index 37f18c4..48a5580 100644
--- a/lib/Net/OpenSSH/ModuleLoader.pm
+++ b/lib/Net/OpenSSH/ModuleLoader.pm
@@ -11,6 +11,7 @@ our @EXPORT = qw(_load_module);
 
 sub _load_module {
     my ($module, $version) = @_;
+    defined $module or croak "bad Perl module name";
     $module =~ /\A[A-Za-z_]\w*(?:::\w+)*\z/
         or croak "bad Perl module name $module";
     $loaded_module{$module} ||= do {
diff --git a/t/module-loader.t b/t/module-loader.t
index 6fddd9c..8e3db42 100644
--- a/t/module-loader.t
+++ b/t/module-loader.t
@@ -3,7 +3,7 @@
 use strict;
 use warnings;
 
-use Test::More tests => 5;
+use Test::More tests => 6;
 
 use Net::OpenSSH::ModuleLoader;
 
@@ -12,6 +12,9 @@ ok(_load_module('strict'), 'loads a valid module name');
 eval { _load_module('strict; die "boom"') };
 like($@, qr/bad Perl module name/, 'rejects unsafe module names');
 
+eval { _load_module(undef) };
+like($@, qr/bad Perl module name/, 'rejects undefined module names without warnings');
+
 eval { _load_module('strict', 999_999) };
 like($@, qr/strict version 999999 required|strict version 999999 required--this is only version/,
      'uses standard VERSION checks for too-new requirements');