1 files changed, 72 insertions, 0 deletions
diff --git a/lib/chef/resource/openssl_dhparam.rb b/lib/chef/resource/openssl_dhparam.rb
new file mode 100644
index 0000000000..6260f83f82
--- /dev/null
+++ b/lib/chef/resource/openssl_dhparam.rb
@@ -0,0 +1,72 @@
+#
+# Copyright:: Copyright 2008-2016, Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require "chef/resource"
+
+class Chef
+  class Resource
+    # @author Charles Johnson <charles@chef.io>
+    # generates dhparam.pem files. If a valid dhparam.pem file is found at the specified location,
+    # no new file will be created. If a file is found at the specified location but it is not a valid
+    # dhparam file, it will be overwritten.
+    class OpensslDhparam < Chef::Resource
+      require "openssl"
+
+      resource_name :openssl_dhparam
+
+      property :path,        String, name_property: true
+      property :key_length,  equal_to: [1024, 2048, 4096, 8192], default: 2048
+      property :generator,   equal_to: [2, 5], default: 2
+      property :owner,       String, default: "root"
+      property :group,       String, default: node["root_group"]
+      property :mode,        [Integer, String], default: "0640"
+
+      action :create do
+        return if dhparam_pem_valid?(new_resource.path)
+
+        converge_by("Create a dhparam file #{new_resource.path}") do
+          dhparam_content = gen_dhparam(new_resource.key_length, new_resource.generator).to_pem
+
+          declare_resource(:file, new_resource.name) do
+            action :create
+            owner new_resource.owner
+            group new_resource.group
+            mode new_resource.mode
+            sensitive true
+            content dhparam_content
+          end
+        end
+      end
+
+      action_class do
+        # Check if the dhparam.pem file exists
+        # Verify the dhparam.pem file contains a key
+        def dhparam_pem_valid?(dhparam_pem_path)
+          return false unless ::File.exist?(dhparam_pem_path)
+          dhparam = OpenSSL::PKey::DH.new File.read(dhparam_pem_path)
+          dhparam.params_ok?
+        end
+
+        # generate a dhparam file
+        def gen_dhparam(key_length, generator)
+          raise ArgumentError, "Key length must be a power of 2 greater than or equal to 1024" unless key_length_valid?(key_length)
+          OpenSSL::PKey::DH.new(key_length, generator)
+        end
+      end
+    end
+  end
+end