Improve Hostname Validation (#32)

Author: ahoshaiyan

lib/mini_defender/rules/hostname.rb

@@ -1,19 +1,24 @@
 # frozen_string_literal: true
 
 class MiniDefender::Rules::Hostname < MiniDefender::Rule
-  HOSTNAME_REGEX = /\A[a-zA-Z0-9][a-zA-Z0-9\-]{1,63}(\.[a-zA-Z0-9][a-zA-Z0-9\-]{1,63})+\.?\z/
+  HOSTNAME_REGEX = /\A([a-zA-Z0-9][a-zA-Z0-9\-]{,62})(\.[a-zA-Z0-9][a-zA-Z0-9\-]{0,62})+\.?\z/
 
   def self.signature
     'hostname'
   end
 
   def coerce(value)
-    value.to_s.downcase.strip
+    value.to_s
+      .downcase
+      .strip
+      .gsub(/.\z/, '')
   end
 
   def passes?(attribute, value, validator)
     value = value.to_s.downcase.strip
-    return false if value.length > 255
+    if value.length > 255
+      return false
+    end
 
     value.match?(HOSTNAME_REGEX)
   end

lib/mini_defender/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module MiniDefender
-  VERSION = "0.7.1"
+  VERSION = "0.7.2"
 end

test/rules/hostname_test.rb

@@ -0,0 +1,49 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class PasswordTest < Minitest::Test
+  def setup
+    @rule = MiniDefender::Rules::Hostname.new
+  end
+
+  def test_valid_hostname
+    assert(@rule.passes?('hostname', 'www.example.com', nil))
+  end
+
+  def test_pass_for_trailing_dot
+    assert(@rule.passes?('hostname', 'www.example.com.', nil))
+  end
+
+  def test_must_remove_trailing_dot
+    assert(@rule.coerce('www.example.com'))
+  end
+
+  def test_fail_for_non_ascii
+    refute(@rule.passes?('hostname', 'www.مثال.com', nil))
+  end
+
+  def test_allow_long_label
+    label = '1' * 63
+    assert(@rule.passes?('hostname', "#{label}.example.com", nil))
+  end
+
+  def test_allow_long_hostname
+    label = '1' * 63
+    assert(@rule.passes?('hostname', "#{label}.#{label}.#{label}.example.com", nil))
+  end
+
+  def single_char_subdomain_hostname
+    assert(@rule.passes?('hostname', 'w.example.com', nil))
+  end
+
+  def test_must_fail_for_64_plus_label
+    label = '1' * 64
+    refute(@rule.passes?('hostname', "#{label}.example.com", nil))
+  end
+
+  def test_must_fail_for_254_plus_domain
+    label = '1' * 63
+    refute(@rule.passes?('hostname', "#{label}.#{label}.#{label}.#{label}.#{label}.example.com", nil))
+  end
+end