Add PostgreSQL authentication backend (minetest#9756)

* Add PostgreSQL authentication backend

src/database/database-postgresql.cpp

@@ -166,6 +166,11 @@ void Database_PostgreSQL::endSave()
  checkResults(PQexec(m_conn, "COMMIT;"));
 }
 
+void Database_PostgreSQL::rollback()
+{
+ checkResults(PQexec(m_conn, "ROLLBACK;"));
+}
+
 MapDatabasePostgreSQL::MapDatabasePostgreSQL(const std::string &connect_string):
  Database_PostgreSQL(connect_string),
  MapDatabase()
@@ -637,4 +642,174 @@ void PlayerDatabasePostgreSQL::listPlayers(std::vector<std::string> &res)
  PQclear(results);
 }
 
+AuthDatabasePostgreSQL::AuthDatabasePostgreSQL(const std::string &connect_string) :
+ Database_PostgreSQL(connect_string), AuthDatabase()
+{
+ connectToDatabase();
+}
+
+void AuthDatabasePostgreSQL::createDatabase()
+{
+ createTableIfNotExists("auth",
+ "CREATE TABLE auth ("
+ "id SERIAL,"
+ "name TEXT UNIQUE,"
+ "password TEXT,"
+ "last_login INT NOT NULL DEFAULT 0,"
+ "PRIMARY KEY (id)"
+ ");");
+
+ createTableIfNotExists("user_privileges",
+ "CREATE TABLE user_privileges ("
+ "id INT,"
+ "privilege TEXT,"
+ "PRIMARY KEY (id, privilege),"
+ "CONSTRAINT fk_id FOREIGN KEY (id) REFERENCES auth (id) ON DELETE CASCADE"
+ ");");
+}
+
+void AuthDatabasePostgreSQL::initStatements()
+{
+ prepareStatement("auth_read", "SELECT id, name, password, last_login FROM auth WHERE name = $1");
+ prepareStatement("auth_write", "UPDATE auth SET name = $1, password = $2, last_login = $3 WHERE id = $4");
+ prepareStatement("auth_create", "INSERT INTO auth (name, password, last_login) VALUES ($1, $2, $3) RETURNING id");
+ prepareStatement("auth_delete", "DELETE FROM auth WHERE name = $1");
+
+ prepareStatement("auth_list_names", "SELECT name FROM auth ORDER BY name DESC");
+
+ prepareStatement("auth_read_privs", "SELECT privilege FROM user_privileges WHERE id = $1");
+ prepareStatement("auth_write_privs", "INSERT INTO user_privileges (id, privilege) VALUES ($1, $2)");
+ prepareStatement("auth_delete_privs", "DELETE FROM user_privileges WHERE id = $1");
+}
+
+bool AuthDatabasePostgreSQL::getAuth(const std::string &name, AuthEntry &res)
+{
+ pingDatabase();
+
+ const char *values[] = { name.c_str() };
+ PGresult *result = execPrepared("auth_read", 1, values, false, false);
+ int numrows = PQntuples(result);
+ if (numrows == 0) {
+ PQclear(result);
+ return false;
+ }
+
+ res.id = pg_to_uint(result, 0, 0);
+ res.name = std::string(PQgetvalue(result, 0, 1), PQgetlength(result, 0, 1));
+ res.password = std::string(PQgetvalue(result, 0, 2), PQgetlength(result, 0, 2));
+ res.last_login = pg_to_int(result, 0, 3);
+
+ PQclear(result);
+
+ std::string playerIdStr = itos(res.id);
+ const char *privsValues[] = { playerIdStr.c_str() };
+ PGresult *results = execPrepared("auth_read_privs", 1, privsValues, false);
+
+ numrows = PQntuples(results);
+ for (int row = 0; row < numrows; row++)
+ res.privileges.emplace_back(PQgetvalue(results, row, 0));
+
+ PQclear(results);
+
+ return true;
+}
+
+bool AuthDatabasePostgreSQL::saveAuth(const AuthEntry &authEntry)
+{
+ pingDatabase();
+
+ beginSave();
+
+ std::string lastLoginStr = itos(authEntry.last_login);
+ std::string idStr = itos(authEntry.id);
+ const char *values[] = {
+ authEntry.name.c_str() ,
+ authEntry.password.c_str(),
+ lastLoginStr.c_str(),
+ idStr.c_str(),
+ };
+ execPrepared("auth_write", 4, values);
+
+ writePrivileges(authEntry);
+
+ endSave();
+ return true;
+}
+
+bool AuthDatabasePostgreSQL::createAuth(AuthEntry &authEntry)
+{
+ pingDatabase();
+
+ std::string lastLoginStr = itos(authEntry.last_login);
+ const char *values[] = {
+ authEntry.name.c_str() ,
+ authEntry.password.c_str(),
+ lastLoginStr.c_str()
+ };
+
+ beginSave();
+
+ PGresult *result = execPrepared("auth_create", 3, values, false, false);
+
+ int numrows = PQntuples(result);
+ if (numrows == 0) {
+ errorstream << "Strange behaviour on auth creation, no ID returned." << std::endl;
+ PQclear(result);
+ rollback();
+ return false;
+ }
+
+ authEntry.id = pg_to_uint(result, 0, 0);
+ PQclear(result);
+
+ writePrivileges(authEntry);
+
+ endSave();
+ return true;
+}
+
+bool AuthDatabasePostgreSQL::deleteAuth(const std::string &name)
+{
+ pingDatabase();
+
+ const char *values[] = { name.c_str() };
+ execPrepared("auth_delete", 1, values);
+
+ // privileges deleted by foreign key on delete cascade
+ return true;
+}
+
+void AuthDatabasePostgreSQL::listNames(std::vector<std::string> &res)
+{
+ pingDatabase();
+
+ PGresult *results = execPrepared("auth_list_names", 0,
+ NULL, NULL, NULL, false, false);
+
+ int numrows = PQntuples(results);
+
+ for (int row = 0; row < numrows; ++row)
+ res.emplace_back(PQgetvalue(results, row, 0));
+
+ PQclear(results);
+}
+
+void AuthDatabasePostgreSQL::reload()
+{
+ // noop for PgSQL
+}
+
+void AuthDatabasePostgreSQL::writePrivileges(const AuthEntry &authEntry)
+{
+ std::string authIdStr = itos(authEntry.id);
+ const char *values[] = { authIdStr.c_str() };
+ execPrepared("auth_delete_privs", 1, values);
+
+ for (const std::string &privilege : authEntry.privileges) {
+ const char *values[] = { authIdStr.c_str(), privilege.c_str() };
+ execPrepared("auth_write_privs", 2, values);
+ }
+}
+
+
 #endif // USE_POSTGRESQL

src/database/database-postgresql.h

@@ -36,6 +36,7 @@ class Database_PostgreSQL: public Database
 
  void beginSave();
  void endSave();
+ void rollback();
 
  bool initialized() const;
 
@@ -148,3 +149,26 @@ class PlayerDatabasePostgreSQL : private Database_PostgreSQL, public PlayerDatab
 private:
  bool playerDataExists(const std::string &playername);
 };
+
+class AuthDatabasePostgreSQL : private Database_PostgreSQL, public AuthDatabase
+{
+public:
+ AuthDatabasePostgreSQL(const std::string &connect_string);
+ virtual ~AuthDatabasePostgreSQL() = default;
+
+ virtual void pingDatabase() { Database_PostgreSQL::pingDatabase(); }
+
+ virtual bool getAuth(const std::string &name, AuthEntry &res);
+ virtual bool saveAuth(const AuthEntry &authEntry);
+ virtual bool createAuth(AuthEntry &authEntry);
+ virtual bool deleteAuth(const std::string &name);
+ virtual void listNames(std::vector<std::string> &res);
+ virtual void reload();
+
+protected:
+ virtual void createDatabase();
+ virtual void initStatements();
+
+private:
+ virtual void writePrivileges(const AuthEntry &authEntry);
+};

src/serverenvironment.cpp

@@ -2187,6 +2187,14 @@ AuthDatabase *ServerEnvironment::openAuthDatabase(
  if (name == "sqlite3")
  return new AuthDatabaseSQLite3(savedir);
 
+#if USE_POSTGRESQL
+ if (name == "postgresql") {
+ std::string connect_string;
+ conf.getNoEx("pgsql_auth_connection", connect_string);
+ return new AuthDatabasePostgreSQL(connect_string);
+ }
+#endif
+
  if (name == "files")
  return new AuthDatabaseFiles(savedir);