Update DN class in migration

db/post_migrate/20170921101004_normalize_ldap_extern_uids.rb

@@ -19,6 +19,12 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
       UnsupportedDnFormatError = Class.new(StandardError)
 
       class DN
+        def self.normalize_value(given_value)
+          dummy_dn = "placeholder=#{given_value}"
+          normalized_dn = new(*dummy_dn).to_normalized_s
+          normalized_dn.sub(/\Aplaceholder=/, '')
+        end
+
         ##
         # Initialize a DN, escaping as required. Pass in attributes in name/value
         # pairs. If there is a left over argument, it will be appended to the dn
@@ -28,22 +34,31 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
         # so storing the dn as an escaped String and parsing parts as required
         # with a state machine seems sensible.
         def initialize(*args)
-          buffer = StringIO.new
-
-          args.each_index do |index|
-            buffer << "=" if index.odd?
-            buffer << "," if index.even? && index != 0
+          @dn = if args.length > 1
+                  initialize_array(args)
+                else
+                  initialize_string(args[0])
+                end
+        end
 
-            arg = args[index].downcase
+        def initialize_array(args)
+          buffer = StringIO.new
 
-            buffer << if index < args.length - 1 || index.odd?
-                        self.class.escape(arg)
-                      else
-                        arg
+          args.each_with_index do |arg, index|
+            if index.even? # key
+              buffer << "," if index > 0
+              buffer << arg
+            else # value
+              buffer << "="
+              buffer << self.class.escape(arg)
+            end
           end
+
+          buffer.string
         end
 
-          @dn = buffer.string
+        def initialize_string(arg)
+          arg.to_s
         end
 
         ##
@@ -58,11 +73,11 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
           value = StringIO.new
           hex_buffer = ""
 
-          @dn.each_char do |char|
+          @dn.each_char.with_index do |char, dn_index|
             case state
             when :key then
               case char
-              when 'a'..'z' then
+              when 'a'..'z', 'A'..'Z' then
                 state = :key_normal
                 key << char
               when '0'..'9' then
@@ -74,7 +89,7 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
             when :key_normal then
               case char
               when '=' then state = :value
-              when 'a'..'z', '0'..'9', '-', ' ' then key << char
+              when 'a'..'z', 'A'..'Z', '0'..'9', '-', ' ' then key << char
               else raise(MalformedDnError, "Unrecognized RDN attribute type name character \"#{char}\"")
               end
             when :key_oid then
@@ -93,7 +108,7 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
                 value << char
               when ',' then
                 state = :key
-                yield key.string.strip, value.string.rstrip
+                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
                 key = StringIO.new
                 value = StringIO.new
               else
@@ -105,7 +120,7 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
               when '\\' then state = :value_normal_escape
               when ',' then
                 state = :key
-                yield key.string.strip, value.string.rstrip
+                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
                 key = StringIO.new
                 value = StringIO.new
               when '+' then raise(UnsupportedDnFormatError, "Multivalued RDNs are not supported")
@@ -113,34 +128,20 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
               end
             when :value_normal_escape then
               case char
-              when '0'..'9', 'a'..'f' then
+              when '0'..'9', 'a'..'f', 'A'..'F' then
                 state = :value_normal_escape_hex
                 hex_buffer = char
-              when /\s/ then
-                state = :value_normal_escape_whitespace
-                value << char
               else
                 state = :value_normal
                 value << char
               end
             when :value_normal_escape_hex then
               case char
-              when '0'..'9', 'a'..'f' then
+              when '0'..'9', 'a'..'f', 'A'..'F' then
                 state = :value_normal
                 value << "#{hex_buffer}#{char}".to_i(16).chr
               else raise(MalformedDnError, "Invalid escaped hex code \"\\#{hex_buffer}#{char}\"")
               end
-            when :value_normal_escape_whitespace then
-              case char
-              when '\\' then state = :value_normal_escape
-              when ',' then
-                state = :key
-                yield key.string.strip, value.string # Don't strip trailing escaped space!
-                key = StringIO.new
-                value = StringIO.new
-              when '+' then raise(UnsupportedDnFormatError, "Multivalued RDNs are not supported")
-              else value << char
-              end
             when :value_quoted then
               case char
               when '\\' then state = :value_quoted_escape
@@ -149,7 +150,7 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
               end
             when :value_quoted_escape then
               case char
-              when '0'..'9', 'a'..'f' then
+              when '0'..'9', 'a'..'f', 'A'..'F' then
                 state = :value_quoted_escape_hex
                 hex_buffer = char
               else
@@ -158,27 +159,27 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
               end
             when :value_quoted_escape_hex then
               case char
-              when '0'..'9', 'a'..'f' then
+              when '0'..'9', 'a'..'f', 'A'..'F' then
                 state = :value_quoted
                 value << "#{hex_buffer}#{char}".to_i(16).chr
               else raise(MalformedDnError, "Expected the second character of a hex pair inside a double quoted value, but got \"#{char}\"")
               end
             when :value_hexstring then
               case char
-              when '0'..'9', 'a'..'f' then
+              when '0'..'9', 'a'..'f', 'A'..'F' then
                 state = :value_hexstring_hex
                 value << char
               when ' ' then state = :value_end
               when ',' then
                 state = :key
-                yield key.string.strip, value.string.rstrip
+                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
                 key = StringIO.new
                 value = StringIO.new
               else raise(MalformedDnError, "Expected the first character of a hex pair, but got \"#{char}\"")
               end
             when :value_hexstring_hex then
               case char
-              when '0'..'9', 'a'..'f' then
+              when '0'..'9', 'a'..'f', 'A'..'F' then
                 state = :value_hexstring
                 value << char
               else raise(MalformedDnError, "Expected the second character of a hex pair, but got \"#{char}\"")
@@ -188,7 +189,7 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
               when ' ' then state = :value_end
               when ',' then
                 state = :key
-                yield key.string.strip, value.string.rstrip
+                yield key.string.strip, rstrip_except_escaped(value.string, dn_index)
                 key = StringIO.new
                 value = StringIO.new
               else raise(MalformedDnError, "Expected the end of an attribute value, but got \"#{char}\"")
@@ -201,7 +202,25 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
           raise(MalformedDnError, 'DN string ended unexpectedly') unless
             [:value, :value_normal, :value_hexstring, :value_end].include? state
 
-          yield key.string.strip, value.string.rstrip
+          yield key.string.strip, rstrip_except_escaped(value.string, @dn.length)
+        end
+
+        def rstrip_except_escaped(str, dn_index)
+          str_ends_with_whitespace = str.match(/\s\z/)
+
+          if str_ends_with_whitespace
+            dn_part_ends_with_escaped_whitespace = @dn[0, dn_index].match(/\\(\s+)\z/)
+
+            if dn_part_ends_with_escaped_whitespace
+              dn_part_rwhitespace = dn_part_ends_with_escaped_whitespace[1]
+              num_chars_to_remove = dn_part_rwhitespace.length - 1
+              str = str[0, str.length - num_chars_to_remove]
+            else
+              str.rstrip!
+            end
+          end
+
+          str
         end
 
         ##
@@ -221,7 +240,7 @@ class NormalizeLdapExternUids < ActiveRecord::Migration
         ##
         # Return the DN as an escaped and normalized string.
         def to_normalized_s
-          self.class.new(*to_a).to_s
+          self.class.new(*to_a).to_s.downcase
         end
 
         # https://tools.ietf.org/html/rfc4514 section 2.4 lists these exceptions