Extend test coverage for openssl modules (#27548)

* openssl_privatekey: Extend test coverage

Extend the coverage of the integration test for the module
openssl_privatekey.

New tests have been added:

  * passphrase
  * idempotence
  * removal

Co-Authored-By: Pierre-Louis Bonicoli <pierre-louis.bonicoli@gmx.fr>

* openssl_publickey: Extend test coverage

Extend the coverage on the integration test for the module
openssl_publickey.

New tests have been added:

  * OpenSSH format
  * passphrase
  * idempotence
  * removal

lib/ansible/module_utils/crypto.py

@@ -29,6 +29,7 @@ import hashlib
 import os
 
 from ansible.module_utils import six
+from ansible.module_utils._text import to_bytes
 
 
 class OpenSSLObjectError(Exception):
@@ -63,7 +64,7 @@ def load_privatekey(path, passphrase=None):
         if passphrase:
             privatekey = crypto.load_privatekey(crypto.FILETYPE_PEM,
                                                 open(path, 'rb').read(),
-                                                passphrase)
+                                                to_bytes(passphrase))
         else:
             privatekey = crypto.load_privatekey(crypto.FILETYPE_PEM,
                                                 open(path, 'rb').read())