Migrate the keystone.common.cms to keystoneclient

- Add checking the openssl return code 2, related to following review

  https://review.openstack.org/#/c/22716/

- Add support set subprocess to the cms, when we already know which
  subprocess to use.

Closes-Bug: #1142574
Change-Id: I3f86e6ca8bb7738f57051ce7f0f5662b20e7a22b

test_auth_token_middleware.py

@@ -31,6 +31,7 @@ import mock
 import webob
 
 from keystoneclient.common import cms
+from keystoneclient import exceptions
 from keystoneclient.middleware import auth_token
 from keystoneclient.openstack.common import jsonutils
 from keystoneclient.openstack.common import memorycache
@@ -876,7 +877,7 @@ class CertDownloadMiddlewareTest(BaseAuthTokenMiddlewareTest):
         httpretty.register_uri(httpretty.GET,
                                "%s/v2.0/certificates/signing" % BASE_URI,
                                status=404)
-        self.assertRaises(cms.subprocess.CalledProcessError,
+        self.assertRaises(exceptions.CertificateConfigError,
                           self.middleware.verify_signed_token,
                           client_fixtures.SIGNED_TOKEN_SCOPED)
 

test_cms.py

@@ -0,0 +1,26 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+#    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.
+
+from keystoneclient.common import cms
+from keystoneclient import exceptions
+from keystoneclient.tests import utils
+
+
+class CMSTest(utils.TestCase):
+    def test_cms_verify(self):
+        self.assertRaises(exceptions.CertificateConfigError,
+                          cms.cms_verify,
+                          'data',
+                          'no_exist_cert_file',
+                          'no_exist_ca_file')