config: support .include directive

OpenSSL 1.1.1 introduces a new '.include' directive. Update our config parser to support that. As mentioned in the referenced GitHub issue, we should use the OpenSSL API instead of implementing the parsing logic ourselves, but it will need backwards-incompatible changes which we can't backport to stable versions. So continue to use the Ruby implementation for now. Squashed in additional changes by Vít Ondruch to support '.include = ' syntax. Reference: #208
ruby · rhenium · Feb 17, 2020 · Aug 16, 2018 · Dec 13, 2019 · 2ad65b5f673f0bb8741bc0d5a737bd0a3cccb65e
commit 2ad65b5f673f0bb8741bc0d5a737bd0a3cccb65e
diff --git a/lib/openssl/config.rb b/lib/openssl/config.rb
@@ -76,29 +76,44 @@ def get_key_string(data, section, key) # :nodoc:
       def parse_config_lines(io)
         section = 'default'
         data = {section => {}}
-        while definition = get_definition(io)
+        io_stack = [io]
+        while definition = get_definition(io_stack)
           definition = clear_comments(definition)
           next if definition.empty?
-          if definition[0] == ?[
+          case definition
+          when /\A\[/
             if /\[([^\]]*)\]/ =~ definition
               section = $1.strip
               data[section] ||= {}
             else
               raise ConfigError, "missing close square bracket"
             end
-          else
-            if /\A([^:\s]*)(?:::([^:\s]*))?\s*=(.*)\z/ =~ definition
-              if $2
-                section = $1
-                key = $2
-              else
-                key = $1
+          when /\A\.include (\s*=\s*)?(.+)\z/
+            path = $2
+            if File.directory?(path)
+              files = Dir.glob(File.join(path, "*.{cnf,conf}"), File::FNM_EXTGLOB)
+            else
+              files = [path]
+            end
+
+            files.each do |filename|
+              begin
+                io_stack << StringIO.new(File.read(filename))
+              rescue
+                raise ConfigError, "could not include file '%s'" % filename
               end
-              value = unescape_value(data, section, $3)
-              (data[section] ||= {})[key] = value.strip
+            end
+          when /\A([^:\s]*)(?:::([^:\s]*))?\s*=(.*)\z/
+            if $2
+              section = $1
+              key = $2
             else
-              raise ConfigError, "missing equal sign"
+              key = $1
             end
+            value = unescape_value(data, section, $3)
+            (data[section] ||= {})[key] = value.strip
+          else
+            raise ConfigError, "missing equal sign"
           end
         end
         data
@@ -211,10 +226,10 @@ def clear_comments(line)
         scanned.join
       end
 
-      def get_definition(io)
-        if line = get_line(io)
+      def get_definition(io_stack)
+        if line = get_line(io_stack)
           while /[^\\]\\\z/ =~ line
-            if extra = get_line(io)
+            if extra = get_line(io_stack)
               line += extra
             else
               break
@@ -224,9 +239,12 @@ def get_definition(io)
         end
       end
 
-      def get_line(io)
-        if line = io.gets
-          line.gsub(/[\r\n]*/, '')
+      def get_line(io_stack)
+        while io = io_stack.last
+          if line = io.gets
+            return line.gsub(/[\r\n]*/, '')
+          end
+          io_stack.pop
         end
       end
     end

diff --git a/test/test_config.rb b/test/test_config.rb
@@ -120,6 +120,49 @@ def test_s_parse_format
     assert_equal("error in line 7: missing close square bracket", excn.message)
   end
 
+  def test_s_parse_include
+    in_tmpdir("ossl-config-include-test") do |dir|
+      Dir.mkdir("child")
+      File.write("child/a.conf", <<~__EOC__)
+        [default]
+        file-a = a.conf
+        [sec-a]
+        a = 123
+      __EOC__
+      File.write("child/b.cnf", <<~__EOC__)
+        [default]
+        file-b = b.cnf
+        [sec-b]
+        b = 123
+      __EOC__
+      File.write("include-child.conf", <<~__EOC__)
+        key_outside_section = value_a
+        .include child
+      __EOC__
+
+      include_file = <<~__EOC__
+        [default]
+        file-main = unnamed
+        [sec-main]
+        main = 123
+        .include = include-child.conf
+      __EOC__
+
+      # Include a file by relative path
+      c1 = OpenSSL::Config.parse(include_file)
+      assert_equal(["default", "sec-a", "sec-b", "sec-main"], c1.sections.sort)
+      assert_equal(["file-main", "file-a", "file-b"], c1["default"].keys)
+      assert_equal({"a" => "123"}, c1["sec-a"])
+      assert_equal({"b" => "123"}, c1["sec-b"])
+      assert_equal({"main" => "123", "key_outside_section" => "value_a"}, c1["sec-main"])
+
+      # Relative paths are from the working directory
+      assert_raise(OpenSSL::ConfigError) do
+        Dir.chdir("child") { OpenSSL::Config.parse(include_file) }
+      end
+    end
+  end
+
   def test_s_load
     # alias of new
     c = OpenSSL::Config.load
@@ -299,6 +342,17 @@ def test_clone
     @it['newsection'] = {'a' => 'b'}
     assert_not_equal(@it.sections.sort, c.sections.sort)
   end
+
+  private
+
+  def in_tmpdir(*args)
+    Dir.mktmpdir(*args) do |dir|
+      dir = File.realpath(dir)
+      Dir.chdir(dir) do
+        yield dir
+      end
+    end
+  end
 end
 
 end