Handle Redfish PasswordChangeRequired

This enhances BMCWeb authentication to recognize when the user's password is
correct but expired.  The Redfish SessionService is enhanced to comply with
the Redfish PasswordChangeRequired spec which allows the session to be
created, but limits that sesion to changing the password only, and includes
the PasswordChangeRequired message in the response body.

Specifically, when the account's password is expired, a successful
authentication via the following interfaces will have these results:
- POST /redfish/v1/SessionService/Sessions -- follows Redfish spec
- POST /login -- creates a session limited to changing the password,
                 similar to Redfish
- Basic authentication -- continues to treat the password
  change required condition as an authentication failure and gives no
  indication the password is expired.
- Cookie auth -- works as before
- Token auth -- works as before

This patchset is intended to allow web applications to use the presence
of the Redfish PasswordChangeRequired message or the extendedMessage
field to trigger the password change dialog.

This does not implement the PasswordChangeRequired property in the
ManagerAccount resource.

This implements the Redfish privilege overrides associated with the
ConfigureSelf privilege.  Specifically, this correctly implements the
Password property override, and the ManagerAccount Resource URI override.

When an API results in 403 Forbidden and the issuing session has the
PasswordChangeRequired condition, appropriate JSON is given.

Tested:
  Yes, see https://github.com/openbmc/bmcweb/issues/103
  No, did not run Redfish validator

Signed-off-by: Joseph Reynolds <joseph-reynolds@charter.net>
Change-Id: Ibbf5f6414ac55c0e7bea14c721f6db227b52fe40
diff --git a/redfish-core/include/node.hpp b/redfish-core/include/node.hpp
index 5819527..9d383a9 100644
--- a/redfish-core/include/node.hpp
+++ b/redfish-core/include/node.hpp
@@ -20,6 +20,7 @@
 #include "webserver_common.hpp"
 
 #include <error_messages.hpp>
+#include <sessions.hpp>
 #include <vector>
 
 #include "crow/http_request.h"
@@ -168,6 +169,28 @@
         res.result(boost::beast::http::status::method_not_allowed);
         res.end();
     }
+
+    /* @brief Would the operation be allowed if the user did not have
+     * the ConfigureSelf Privilege?
+     *
+     * @param req      the request
+     * @param verb     the operation's verb
+     *
+     * @returns        True if allowed, false otherwise
+     */
+    inline bool isAllowedWithoutConfigureSelf(const crow::Request& req)
+    {
+        const std::string& userRole =
+            crow::persistent_data::UserRoleMap::getInstance().getUserRole(
+                req.session->username);
+        Privileges effectiveUserPrivileges =
+            redfish::getUserPrivileges(userRole);
+        effectiveUserPrivileges.resetSinglePrivilege("ConfigureSelf");
+        const auto& requiredPrivilegesIt = entityPrivileges.find(req.method());
+        return (requiredPrivilegesIt != entityPrivileges.end()) and
+               isOperationAllowedWithPrivileges(requiredPrivilegesIt->second,
+                                                effectiveUserPrivileges);
+    }
 };
 
 } // namespace redfish