Files
scylladb/auth/transitional.cc
Jesse Haber-Kucharsky 9117a689cf auth: Fix const correctness
This patch came about because of an important (and obvious, in
hindsight) realization: instances of the authorizer, role manager, and
authenticator are clients for access-control state and not the state
itself. This is reflected directly in Scylla: `auth::service` is
sharded across cores and this is possible because each instance queries
and modifies the same global state.

To give more examples, the value of an instance of `std::vector<int>` is
the structure of the container and its contents. The value of `int
file_descriptor` is an identifier for state maintained elsewhere.

Having watched an excellent talk by Herb Sutter [1] and having read an
informative blog post [2], it's clear that a member function marked
`const` communicates that the observable state of the instance is not
modified.

Thus, the member functions of the role-manager, authenticator, and
authorizer clients should not be marked `const` only if the state of the
client itself is observably changed. By this principle, member functions
which do not change the state of the client, but which mutate the global
state the client is associated with (for example, by creating a role)
are marked `const`.

The `start` (and `stop`) functions of the client have the dual role of
initializing (finalizing) both the local client state and the
external state; they are not marked `const`.

[1] https://herbsutter.com/2013/01/01/video-you-dont-know-const-and-mutable/

[2] http://talesofcpp.fusionfenix.com/post-2/episode-one-to-be-or-not-to-be-const
2018-03-14 01:32:43 -04:00

259 lines
8.8 KiB
C++

/*
* Licensed to the Apache Software Foundation (ASF) under one
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*
* 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.
*/
/*
* Copyright (C) 2017 ScyllaDB
*
* Modified by ScyllaDB
*/
/*
* This file is part of Scylla.
*
* Scylla is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Scylla is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Scylla. If not, see <http://www.gnu.org/licenses/>.
*/
#include "auth/authenticated_user.hh"
#include "auth/authenticator.hh"
#include "auth/authorizer.hh"
#include "auth/default_authorizer.hh"
#include "auth/password_authenticator.hh"
#include "auth/permission.hh"
#include "db/config.hh"
#include "utils/class_registrator.hh"
namespace auth {
static const sstring PACKAGE_NAME("com.scylladb.auth.");
static const sstring& transitional_authenticator_name() {
static const sstring name = PACKAGE_NAME + "TransitionalAuthenticator";
return name;
}
static const sstring& transitional_authorizer_name() {
static const sstring name = PACKAGE_NAME + "TransitionalAuthorizer";
return name;
}
class transitional_authenticator : public authenticator {
std::unique_ptr<authenticator> _authenticator;
public:
static const sstring PASSWORD_AUTHENTICATOR_NAME;
transitional_authenticator(cql3::query_processor& qp, ::service::migration_manager& mm)
: transitional_authenticator(std::make_unique<password_authenticator>(qp, mm)) {
}
transitional_authenticator(std::unique_ptr<authenticator> a)
: _authenticator(std::move(a)) {
}
virtual future<> start() override {
return _authenticator->start();
}
virtual future<> stop() override {
return _authenticator->stop();
}
virtual const sstring& qualified_java_name() const override {
return transitional_authenticator_name();
}
virtual bool require_authentication() const override {
return true;
}
virtual authentication_option_set supported_options() const override {
return _authenticator->supported_options();
}
virtual authentication_option_set alterable_options() const override {
return _authenticator->alterable_options();
}
virtual future<authenticated_user> authenticate(const credentials_map& credentials) const override {
auto i = credentials.find(authenticator::USERNAME_KEY);
if ((i == credentials.end() || i->second.empty())
&& (!credentials.count(PASSWORD_KEY) || credentials.at(PASSWORD_KEY).empty())) {
// return anon user
return make_ready_future<authenticated_user>(anonymous_user());
}
return make_ready_future().then([this, &credentials] {
return _authenticator->authenticate(credentials);
}).handle_exception([](auto ep) {
try {
std::rethrow_exception(ep);
} catch (exceptions::authentication_exception&) {
// return anon user
return make_ready_future<authenticated_user>(anonymous_user());
}
});
}
virtual future<> create(stdx::string_view role_name, const authentication_options& options) const override {
return _authenticator->create(role_name, options);
}
virtual future<> alter(stdx::string_view role_name, const authentication_options& options) const override {
return _authenticator->alter(role_name, options);
}
virtual future<> drop(stdx::string_view role_name) const override {
return _authenticator->drop(role_name);
}
virtual const resource_set& protected_resources() const override {
return _authenticator->protected_resources();
}
virtual ::shared_ptr<sasl_challenge> new_sasl_challenge() const override {
class sasl_wrapper : public sasl_challenge {
public:
sasl_wrapper(::shared_ptr<sasl_challenge> sasl)
: _sasl(std::move(sasl)) {
}
virtual bytes evaluate_response(bytes_view client_response) override {
try {
return _sasl->evaluate_response(client_response);
} catch (exceptions::authentication_exception&) {
_complete = true;
return {};
}
}
virtual bool is_complete() const override {
return _complete || _sasl->is_complete();
}
virtual future<authenticated_user> get_authenticated_user() const {
return futurize_apply([this] {
return _sasl->get_authenticated_user().handle_exception([](auto ep) {
try {
std::rethrow_exception(ep);
} catch (exceptions::authentication_exception&) {
// return anon user
return make_ready_future<authenticated_user>(anonymous_user());
}
});
});
}
private:
::shared_ptr<sasl_challenge> _sasl;
bool _complete = false;
};
return ::make_shared<sasl_wrapper>(_authenticator->new_sasl_challenge());
}
};
class transitional_authorizer : public authorizer {
std::unique_ptr<authorizer> _authorizer;
public:
transitional_authorizer(cql3::query_processor& qp, ::service::migration_manager& mm)
: transitional_authorizer(std::make_unique<default_authorizer>(qp, mm)) {
}
transitional_authorizer(std::unique_ptr<authorizer> a)
: _authorizer(std::move(a)) {
}
~transitional_authorizer() {
}
virtual future<> start() override {
return _authorizer->start();
}
virtual future<> stop() override {
return _authorizer->stop();
}
virtual const sstring& qualified_java_name() const override {
return transitional_authorizer_name();
}
virtual future<permission_set> authorize(const role_or_anonymous&, const resource&) const override {
static const permission_set transitional_permissions =
permission_set::of<
permission::CREATE,
permission::ALTER,
permission::DROP,
permission::SELECT,
permission::MODIFY>();
return make_ready_future<permission_set>(transitional_permissions);
}
virtual future<> grant(stdx::string_view s, permission_set ps, const resource& r) const override {
return _authorizer->grant(s, std::move(ps), r);
}
virtual future<> revoke(stdx::string_view s, permission_set ps, const resource& r) const override {
return _authorizer->revoke(s, std::move(ps), r);
}
virtual future<std::vector<permission_details>> list_all() const override {
return _authorizer->list_all();
}
virtual future<> revoke_all(stdx::string_view s) const override {
return _authorizer->revoke_all(s);
}
virtual future<> revoke_all(const resource& r) const override {
return _authorizer->revoke_all(r);
}
virtual const resource_set& protected_resources() const override {
return _authorizer->protected_resources();
}
};
}
//
// To ensure correct initialization order, we unfortunately need to use string literals.
//
static const class_registrator<
auth::authenticator,
auth::transitional_authenticator,
cql3::query_processor&,
::service::migration_manager&> transitional_authenticator_reg(auth::PACKAGE_NAME + "TransitionalAuthenticator");
static const class_registrator<
auth::authorizer,
auth::transitional_authorizer,
cql3::query_processor&,
::service::migration_manager&> transitional_authorizer_reg(auth::PACKAGE_NAME + "TransitionalAuthorizer");