mirror of
https://github.com/scylladb/scylladb.git
synced 2026-04-28 20:27:03 +00:00
0900a88884
Analysis of customer stalls revealed that the function `detail::hash_with_salt` (invoked by `passwords::check`) often blocks the reactor. Internally, this function uses the external `crypt_r` function to compute password hashes, which is CPU-intensive.
This PR addresses the issue in two ways:
1) `sha-512` is now the only password hashing scheme for new passwords (it was already the common-case).
2) `passwords::check` is moved to a dedicated alien thread.
Regarding point 1: before this change, the following hashing schemes were supported by `identify_best_supported_scheme()`: bcrypt_y, bcrypt_a, SHA-512, SHA-256, and MD5. The reason for this was that the `crypt_r` function used for password hashing comes from an external library (currently `libxcrypt`), and the supported hashing algorithms vary depending on the library in use. However:
- The bcrypt schemes never worked properly because their prefixes lack the required round count (e.g. `$2y$` instead of `$2y$05$`). Moreover, bcrypt is slower than SHA-512, so it not good idea to fix or use it.
- SHA-256 and SHA-512 both belong to the SHA-2 family. Libraries that support one almost always support the other, so it’s very unlikely to find SHA-256 without SHA-512.
- MD5 is no longer considered secure for password hashing.
Regarding point 2: the `passwords::check` call now runs on a shared alien thread created at database startup. An `std::mutex` synchronizes that thread with the shards. In theory this could introduce a frequent lock contention, but in practice each shard handles only a few hundred new connections per second—even during storms. There is already `_conns_cpu_concurrency_semaphore` in `generic_server` limits the number of concurrent connection handlers.
Fixes https://github.com/scylladb/scylladb/issues/24524
Backport not needed, as it is a new feature.
Closes scylladb/scylladb#24924
* github.com:scylladb/scylladb:
main: utils: add thread names to alien workers
auth: move passwords::check call to alien thread
test: wait for 3 clients with given username in test_service_level_api
auth: refactor password checking in password_authenticator
auth: make SHA-512 the only password hashing scheme for new passwords
auth: whitespace change in identify_best_supported_scheme()
auth: require scheme as parameter for `generate_salt`
auth: check password hashing scheme support on authenticator start
(cherry picked from commit c762425ea7)
69 lines
1.9 KiB
C++
69 lines
1.9 KiB
C++
/*
|
|
* Copyright (C) 2022-present ScyllaDB
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include "auth/authenticator.hh"
|
|
#include "utils/alien_worker.hh"
|
|
#include <boost/regex_fwd.hpp> // IWYU pragma: keep
|
|
|
|
namespace cql3 {
|
|
|
|
class query_processor;
|
|
|
|
} // namespace cql3
|
|
|
|
namespace service {
|
|
class migration_manager;
|
|
class raft_group0_client;
|
|
}
|
|
|
|
namespace auth {
|
|
|
|
extern const std::string_view certificate_authenticator_name;
|
|
|
|
class certificate_authenticator : public authenticator {
|
|
enum class query_source;
|
|
std::vector<std::pair<query_source, boost::regex>> _queries;
|
|
public:
|
|
certificate_authenticator(cql3::query_processor&, ::service::raft_group0_client&, ::service::migration_manager&, utils::alien_worker&);
|
|
~certificate_authenticator();
|
|
|
|
future<> start() override;
|
|
future<> stop() override;
|
|
|
|
std::string_view qualified_java_name() const override;
|
|
|
|
bool require_authentication() const override;
|
|
|
|
authentication_option_set supported_options() const override;
|
|
authentication_option_set alterable_options() const override;
|
|
|
|
future<authenticated_user> authenticate(const credentials_map& credentials) const override;
|
|
future<std::optional<authenticated_user>> authenticate(session_dn_func) const override;
|
|
|
|
future<> create(std::string_view role_name, const authentication_options& options, ::service::group0_batch& mc) override;
|
|
future<> alter(std::string_view role_name, const authentication_options& options, ::service::group0_batch&) override;
|
|
future<> drop(std::string_view role_name, ::service::group0_batch&) override;
|
|
|
|
future<custom_options> query_custom_options(std::string_view role_name) const override;
|
|
|
|
const resource_set& protected_resources() const override;
|
|
|
|
::shared_ptr<sasl_challenge> new_sasl_challenge() const override;
|
|
|
|
virtual future<> ensure_superuser_is_created() const override {
|
|
return make_ready_future<>();
|
|
}
|
|
private:
|
|
};
|
|
|
|
}
|
|
|