Add `DN#to_s_normalized`

lib/gitlab/ldap/dn.rb

@@ -38,7 +38,7 @@ module Gitlab
           buffer << "," if index % 2 == 0 && index != 0
 
           if index < args.length - 1 || index % 2 == 1
-            buffer << Net::LDAP::DN.escape(args[index])
+            buffer << self.class.escape(args[index])
           else
             buffer << args[index]
           end
@@ -199,6 +199,12 @@ module Gitlab
         @dn
       end
 
+      ##
+      # Return the DN as an escaped and normalized string.
+      def to_s_normalized
+        self.class.new(*to_a).to_s
+      end
+
       # http://tools.ietf.org/html/rfc2253 section 2.4 lists these exceptions
       # for dn values. All of the following must be escaped in any normal string
       # using a single backslash ('\') as escape.

spec/lib/gitlab/ldap/dn_spec.rb

+require 'spec_helper'
+
+describe Gitlab::LDAP::DN do
+  using RSpec::Parameterized::TableSyntax
+
+  describe '#initialize' do
+    subject { described_class.new(given).to_s_normalized }
+
+    # Regarding the telephoneNumber test:
+    #
+    # I am not sure whether a space after the telephoneNumber plus sign is valid,
+    # and I am not sure if this is "proper" behavior under these conditions, and
+    # I am not sure if it matters to us or anyone else, so rather than dig
+    # through RFCs, I am only documenting the behavior here.
+    where(:test_description, :given, :expected) do
+      'strips extraneous whitespace'                                                                 | 'uid     =John Smith ,  ou = People, dc=  example,dc =com'                                            | 'uid=john smith,ou=people,dc=example,dc=com'
+      'strips extraneous whitespace for a DN with a single RDN'                                      | 'uid  =  John Smith'                                                                                  | 'uid=john smith'
+      'strips extraneous whitespace without changing escaped characters'                             | 'uid   =  Sebasti\\c3\\a1n\\ C.\\20Smith\\   ,   ou=People (aka. \\22humans\\")  ,dc=example, dc=com' | 'uid=sebasti\\c3\\a1n\\ c.\\20smith\\ ,ou=people (aka. \\22humans\\"),dc=example,dc=com'
+      'strips extraneous whitespace without modifying the multivalued RDN'                           | 'uid = John Smith  + telephoneNumber  = +1 555-555-5555 , ou = People,dc=example,dc=com'              | 'uid=john smith+telephonenumber=+1 555-555-5555,ou=people,dc=example,dc=com'
+      'strips the space after the plus sign in the telephoneNumber'                                  | 'uid = John Smith  + telephoneNumber  = + 1 555-555-5555 , ou = People,dc=example,dc=com'             | 'uid=john smith+telephonenumber=+1 555-555-5555,ou=people,dc=example,dc=com'
+      'downcases the whole string'                                                                   | 'UID=John Smith,ou=People,dc=example,dc=com'                                                          | 'uid=john smith,ou=people,dc=example,dc=com'
+      'for a null DN (empty string), returns empty string and does not error'                        | ''                                                                                                    | ''
+      'does not strip an escaped leading space in an attribute value (and does not error like Net::LDAP::DN.new does)' | 'uid=\\ John Smith,ou=People,dc=example,dc=com'                                     | 'uid=\\ john smith,ou=people,dc=example,dc=com'
+      'does not strip an escaped trailing space in an attribute value'                               | 'uid=John Smith\\ ,ou=People,dc=example,dc=com'                                                       | 'uid=john smith\\ ,ou=people,dc=example,dc=com'
+      'does not strip an escaped leading newline in an attribute value'                              | 'uid=\\\nJohn Smith,ou=People,dc=example,dc=com'                                                      | 'uid=\\\njohn smith,ou=people,dc=example,dc=com'
+      'does not strip an escaped trailing newline in an attribute value'                             | 'uid=John Smith\\\n,ou=People,dc=example,dc=com'                                                      | 'uid=john smith\\\n,ou=people,dc=example,dc=com'
+      'does not strip an unescaped leading newline (actually an invalid DN)'                         | 'uid=\nJohn Smith,ou=People,dc=example,dc=com'                                                                               | 'uid=\njohn smith,ou=people,dc=example,dc=com'
+      'does not strip an unescaped trailing newline (actually an invalid DN)'                        | 'uid=John Smith\n ,ou=People,dc=example,dc=com'                                                                              | 'uid=john smith\n,ou=people,dc=example,dc=com'
+      'does not strip non whitespace'                                                                | 'uid=John Smith,ou=People,dc=example,dc=com'                                                          | 'uid=john smith,ou=people,dc=example,dc=com'
+      'does not treat escaped equal signs as attribute delimiters'                                   | 'uid= foo  \\=  bar'                                                                                  | 'uid=foo  \\=  bar'
+      'does not treat escaped hex equal signs as attribute delimiters'                               | 'uid= foo  \\3D  bar'                                                                                 | 'uid=foo  \\3d  bar'
+      'does not treat escaped commas as attribute delimiters'                                        | 'uid= John C. Smith, ou=San Francisco\\, CA'                                                          | 'uid=john c. smith,ou=san francisco\\, ca'
+      'does not treat escaped hex commas as attribute delimiters'                                    | 'uid= John C. Smith, ou=San Francisco\\2C CA'                                                         | 'uid=john c. smith,ou=san francisco\\2c ca'
+    end
+
+    with_them do
+      it 'normalizes the DN' do
+        assert_generic_test(test_description, subject, expected)
+      end
+    end
+
+    context 'when the given DN is malformed' do
+      let(:given) { 'uid\\=john' }
+
+      it 'raises MalformedDnError' do
+        expect(subject).to raise_error(MalformedDnError)
+      end
+    end
+  end
+
+  def assert_generic_test(test_description, got, expected)
+    test_failure_message = "Failed test description: '#{test_description}'\n\n    expected: #{expected}\n         got: #{got}"
+    expect(got).to eq(expected), test_failure_message
+  end
+end