Module to generate Diffie-Hellman parameters (#32620)

* Module to generate Diffie-Hellman parameters

Implements #32577

* Add integration tests for openssl_dhparam

* Slightly refactor check to prevent unnecessary regeneration

* Fix code smell in tests

Highly annoying to have to do this again and again and again as the rules change during the game

* Using module.run_command() and module.atomic_move() from a tempfile.

* Remove underscore variable

Ansible prefers dummy

test/integration/targets/openssl_dhparam/tasks/main.yml

@@ -0,0 +1,44 @@
+- block:
+    # This module generates unsafe parameters for testing purposes
+    # otherwise tests would be too slow
+    - name: Generate parameter
+      openssl_dhparam:
+        size: 768
+        path: '{{ output_dir }}/dh768.pem'
+
+    - name: Don't regenerate parameters with no change
+      openssl_dhparam:
+        size: 768
+        path: '{{ output_dir }}/dh768.pem'
+      register: dhparam_changed
+
+    - name: Generate parameters with size option
+      openssl_dhparam:
+        path: '{{ output_dir }}/dh512.pem'
+        size: 512
+
+    - name: Don't regenerate parameters with size option and no change
+      openssl_dhparam:
+        path: '{{ output_dir }}/dh512.pem'
+        size: 512
+      register: dhparam_changed_512
+
+    - copy:
+        src: '{{ output_dir }}/dh768.pem'
+        remote_src: yes
+        dest: '{{ output_dir }}/dh512.pem'
+
+    - name: Re-generate if size is different
+      openssl_dhparam:
+        path: '{{ output_dir }}/dh512.pem'
+        size: 512
+      register: dhparam_changed_to_512
+
+    - name: Force re-generate parameters with size option
+      openssl_dhparam:
+        path: '{{ output_dir }}/dh512.pem'
+        size: 512
+        force: yes
+      register: dhparam_changed_force
+
+    - import_tasks: ../tests/validate.yml