398 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			398 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /*
 | |
|  * Copyright (c) 2016 MariaDB Corporation Ab
 | |
|  *
 | |
|  * Use of this software is governed by the Business Source License included
 | |
|  * in the LICENSE.TXT file and at www.mariadb.com/bsl11.
 | |
|  *
 | |
|  * Change Date: 2022-01-01
 | |
|  *
 | |
|  * On the date above, in accordance with the Business Source License, use
 | |
|  * of this software will be governed by version 2 or later of the General
 | |
|  * Public License.
 | |
|  */
 | |
| 
 | |
| #include "pam_instance.hh"
 | |
| 
 | |
| #include <string>
 | |
| #include <string.h>
 | |
| #include <maxscale/jansson.hh>
 | |
| #include <maxscale/secrets.h>
 | |
| #include <maxscale/mysql_utils.hh>
 | |
| 
 | |
| #define DEFAULT_PAM_DATABASE_NAME "file:pam.db?mode=memory&cache=shared"
 | |
| #define DEFAULT_PAM_TABLE_NAME    "pam_users"
 | |
| using std::string;
 | |
| 
 | |
| /**
 | |
|  * Create an instance.
 | |
|  *
 | |
|  * @param options Listener options
 | |
|  * @return New client authenticator instance or NULL on error
 | |
|  */
 | |
| PamInstance* PamInstance::create(char** options)
 | |
| {
 | |
|     /** Name of the in-memory database */
 | |
|     const string pam_db_name = DEFAULT_PAM_DATABASE_NAME;
 | |
|     /** The table name where we store the users */
 | |
|     const string pam_table_name = DEFAULT_PAM_TABLE_NAME;
 | |
|     /** Deletion statement for the in-memory table */
 | |
|     const string drop_sql = string("DROP TABLE IF EXISTS ") + pam_table_name + ";";
 | |
|     /** CREATE TABLE statement for the in-memory table */
 | |
|     const string create_sql = string("CREATE TABLE ") + pam_table_name
 | |
|         + " (" + FIELD_USER + " varchar(255), "
 | |
|         + FIELD_HOST + " varchar(255), "
 | |
|         + FIELD_DB + " varchar(255), "
 | |
|         + FIELD_ANYDB + " boolean, "
 | |
|         + FIELD_AUTHSTR + " text, "
 | |
|         + FIELD_PROXY + " boolean);";
 | |
| 
 | |
|     if (sqlite3_threadsafe() == 0)
 | |
|     {
 | |
|         MXS_WARNING("SQLite3 was compiled with thread safety off. May cause "
 | |
|                     "corruption of in-memory database.");
 | |
|     }
 | |
| 
 | |
|     bool error = false;
 | |
|     /* This handle may be used from multiple threads, set full mutex. */
 | |
|     sqlite3* dbhandle = NULL;
 | |
|     int db_flags = SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE
 | |
|         | SQLITE_OPEN_SHAREDCACHE | SQLITE_OPEN_FULLMUTEX;
 | |
|     if (sqlite3_open_v2(pam_db_name.c_str(), &dbhandle, db_flags, NULL) != SQLITE_OK)
 | |
|     {
 | |
|         MXS_ERROR("Failed to open SQLite3 handle.");
 | |
|         error = true;
 | |
|     }
 | |
| 
 | |
|     char* err;
 | |
|     if (!error && sqlite3_exec(dbhandle, drop_sql.c_str(), NULL, NULL, &err) != SQLITE_OK)
 | |
|     {
 | |
|         MXS_ERROR("Failed to drop table: '%s'", err);
 | |
|         sqlite3_free(err);
 | |
|         error = true;
 | |
|     }
 | |
|     if (!error && sqlite3_exec(dbhandle, create_sql.c_str(), NULL, NULL, &err) != SQLITE_OK)
 | |
|     {
 | |
|         MXS_ERROR("Failed to create table: '%s'", err);
 | |
|         sqlite3_free(err);
 | |
|         error = true;
 | |
|     }
 | |
| 
 | |
|     PamInstance* instance = NULL;
 | |
|     if (!error
 | |
|         && ((instance = new(std::nothrow) PamInstance(dbhandle, pam_db_name, pam_table_name)) == NULL))
 | |
|     {
 | |
|         sqlite3_close_v2(dbhandle);
 | |
|     }
 | |
|     return instance;
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * Constructor.
 | |
|  *
 | |
|  * @param dbhandle Database handle
 | |
|  * @param dbname Text-form name of @c dbhandle
 | |
|  * @param tablename Name of table where authentication data is saved
 | |
|  */
 | |
| PamInstance::PamInstance(sqlite3* dbhandle, const string& dbname, const string& tablename)
 | |
|     : m_dbname(dbname)
 | |
|     , m_tablename(tablename)
 | |
|     , m_dbhandle(dbhandle)
 | |
| {
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * @brief Add new PAM user entry to the internal user database
 | |
|  *
 | |
|  * @param user   Username
 | |
|  * @param host   Host
 | |
|  * @param db     Database
 | |
|  * @param anydb  Global access to databases
 | |
|  * @param pam_service The PAM service used
 | |
|  * @param proxy  Is the user anonymous with a proxy grant
 | |
|  */
 | |
| void PamInstance::add_pam_user(const char* user, const char* host, const char* db, bool anydb,
 | |
|                                const char* pam_service, bool proxy)
 | |
| {
 | |
|     /**
 | |
|      * The insert query template which adds users to the pam_users table.
 | |
|      *
 | |
|      * Note that 'db' and 'pam_service' are strings that can be NULL and thus they have
 | |
|      * no quotes around them. The quotes for strings are added in this function.
 | |
|      */
 | |
|     const string insert_sql_template =
 | |
|         "INSERT INTO " + m_tablename + " VALUES ('%s', '%s', %s, '%s', %s, '%s')";
 | |
| 
 | |
|     /** Used for NULL value creation in the INSERT query */
 | |
|     const char NULL_TOKEN[] = "NULL";
 | |
|     string db_str;
 | |
| 
 | |
|     if (db)
 | |
|     {
 | |
|         db_str = string("'") + db + "'";
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|         db_str = NULL_TOKEN;
 | |
|     }
 | |
| 
 | |
|     string service_str;
 | |
|     if (pam_service && *pam_service)
 | |
|     {
 | |
|         service_str = string("'") + pam_service + "'";
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|         service_str = NULL_TOKEN;
 | |
|     }
 | |
| 
 | |
|     size_t len = insert_sql_template.length() + strlen(user) + strlen(host) + db_str.length()
 | |
|         + service_str.length() + 1;
 | |
| 
 | |
|     char insert_sql[len + 1];
 | |
|     sprintf(insert_sql,
 | |
|             insert_sql_template.c_str(),
 | |
|             user, host,
 | |
|             db_str.c_str(), anydb ? "1" : "0",
 | |
|             service_str.c_str(),
 | |
|             proxy ? "1" : "0");
 | |
| 
 | |
|     char* err;
 | |
|     if (sqlite3_exec(m_dbhandle, insert_sql, NULL, NULL, &err) != SQLITE_OK)
 | |
|     {
 | |
|         MXS_ERROR("Failed to insert user: %s", err);
 | |
|         sqlite3_free(err);
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|         if (proxy)
 | |
|         {
 | |
|             MXS_INFO("Added anonymous PAM user ''@'%s' with proxy grants using service %s.",
 | |
|                      host, service_str.c_str());
 | |
|         }
 | |
|         else
 | |
|         {
 | |
|             MXS_INFO("Added normal PAM user '%s'@'%s' using service %s.", user, host, service_str.c_str());
 | |
|         }
 | |
|     }
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * @brief Delete old users from the database
 | |
|  */
 | |
| void PamInstance::delete_old_users()
 | |
| {
 | |
|     /** Delete query used to clean up the database before loading new users */
 | |
|     const string delete_query = "DELETE FROM " + m_tablename;
 | |
|     char* err;
 | |
|     if (sqlite3_exec(m_dbhandle, delete_query.c_str(), NULL, NULL, &err) != SQLITE_OK)
 | |
|     {
 | |
|         MXS_ERROR("Failed to delete old users: %s", err);
 | |
|         sqlite3_free(err);
 | |
|     }
 | |
| }
 | |
| 
 | |
| /**
 | |
|  * @brief Populates the internal user database by reading from one of the backend servers
 | |
|  *
 | |
|  * @param service The service the users should be read from
 | |
|  *
 | |
|  * @return MXS_AUTH_LOADUSERS_OK on success, MXS_AUTH_LOADUSERS_ERROR on error
 | |
|  */
 | |
| int PamInstance::load_users(SERVICE* service)
 | |
| {
 | |
|     /** Query that gets all users that authenticate via the pam plugin */
 | |
|     const char PAM_USERS_QUERY[] =
 | |
|         "SELECT u.user, u.host, d.db, u.select_priv, u.authentication_string FROM "
 | |
|         "mysql.user AS u LEFT JOIN mysql.db AS d ON (u.user = d.user AND u.host = d.host) WHERE "
 | |
|         "(u.plugin = 'pam' AND (d.db IS NOT NULL OR u.select_priv = 'Y')) "
 | |
|         "UNION "
 | |
|         "SELECT u.user, u.host, t.db, u.select_priv, u.authentication_string FROM "
 | |
|         "mysql.user AS u LEFT JOIN mysql.tables_priv AS t ON (u.user = t.user AND u.host = t.host) WHERE "
 | |
|         "(u.plugin = 'pam' AND t.db IS NOT NULL AND u.select_priv = 'N') "
 | |
|         "ORDER BY user";
 | |
| #if defined (SS_DEBUG)
 | |
|     const unsigned int PAM_USERS_QUERY_NUM_FIELDS = 5;
 | |
| #endif
 | |
| 
 | |
|     const char* user;
 | |
|     const char* password;
 | |
|     serviceGetUser(service, &user, &password);
 | |
|     int rval = MXS_AUTH_LOADUSERS_ERROR;
 | |
|     char* pw;
 | |
| 
 | |
|     if ((pw = decrypt_password(password)))
 | |
|     {
 | |
|         for (SERVER_REF* servers = service->dbref; servers; servers = servers->next)
 | |
|         {
 | |
|             MYSQL* mysql = mysql_init(NULL);
 | |
|             if (mxs_mysql_real_connect(mysql, servers->server, user, pw))
 | |
|             {
 | |
|                 if (mysql_query(mysql, PAM_USERS_QUERY))
 | |
|                 {
 | |
|                     MXS_ERROR("Failed to query server '%s' for PAM users: '%s'.",
 | |
|                               servers->server->name(), mysql_error(mysql));
 | |
|                 }
 | |
|                 else
 | |
|                 {
 | |
|                     MYSQL_RES* res = mysql_store_result(mysql);
 | |
|                     delete_old_users();
 | |
|                     if (res)
 | |
|                     {
 | |
|                         mxb_assert(mysql_num_fields(res) == PAM_USERS_QUERY_NUM_FIELDS);
 | |
|                         MYSQL_ROW row;
 | |
|                         while ((row = mysql_fetch_row(res)))
 | |
|                         {
 | |
|                             add_pam_user(row[0], row[1],                                // user, host
 | |
|                                          row[2], row[3] && strcasecmp(row[3], "Y") == 0,// db, anydb
 | |
|                                          row[4],                                        // pam service
 | |
|                                          false);                                        // not a proxy
 | |
|                         }
 | |
|                         mysql_free_result(res);
 | |
|                     }
 | |
| 
 | |
|                     if (fetch_anon_proxy_users(servers->server, mysql))
 | |
|                     {
 | |
|                         rval = MXS_AUTH_LOADUSERS_OK;
 | |
|                     }
 | |
|                 }
 | |
|                 mysql_close(mysql);
 | |
| 
 | |
|                 if (rval == MXS_AUTH_LOADUSERS_OK)
 | |
|                 {
 | |
|                     break;
 | |
|                 }
 | |
|             }
 | |
|         }
 | |
|         MXS_FREE(pw);
 | |
|     }
 | |
|     return rval;
 | |
| }
 | |
| 
 | |
| void PamInstance::diagnostic(DCB* dcb)
 | |
| {
 | |
|     json_t* array = diagnostic_json();
 | |
|     mxb_assert(json_is_array(array));
 | |
| 
 | |
|     string result, separator;
 | |
|     size_t index;
 | |
|     json_t* value;
 | |
|     json_array_foreach(array, index, value)
 | |
|     {
 | |
|         // Only print user@host for the non-json version, as this should fit nicely on the console. Add the
 | |
|         // other fields if deemed useful.
 | |
|         const char* user = json_string_value(json_object_get(value, FIELD_USER.c_str()));
 | |
|         const char* host = json_string_value(json_object_get(value, FIELD_HOST.c_str()));
 | |
|         if (user && host)
 | |
|         {
 | |
|             result += separator + user + "@" + host;
 | |
|             separator = " ";
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     if (!result.empty())
 | |
|     {
 | |
|         dcb_printf(dcb, "%s", result.c_str());
 | |
|     }
 | |
|     json_decref(array);
 | |
| }
 | |
| 
 | |
| static int diag_cb_json(void* data, int columns, char** row, char** field_names)
 | |
| {
 | |
|     mxb_assert(columns == NUM_FIELDS);
 | |
|     json_t* obj = json_object();
 | |
|     for (int i = 0; i < columns; i++)
 | |
|     {
 | |
|         json_object_set_new(obj, field_names[i], json_string(row[i]));
 | |
|     }
 | |
|     json_t* arr = static_cast<json_t*>(data);
 | |
|     json_array_append_new(arr, obj);
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| json_t* PamInstance::diagnostic_json()
 | |
| {
 | |
|     json_t* rval = json_array();
 | |
|     char* err;
 | |
|     string select = "SELECT * FROM " + m_tablename + ";";
 | |
|     if (sqlite3_exec(m_dbhandle, select.c_str(), diag_cb_json, rval, &err) != SQLITE_OK)
 | |
|     {
 | |
|         MXS_ERROR("Failed to print users: %s", err);
 | |
|         sqlite3_free(err);
 | |
|     }
 | |
| 
 | |
|     return rval;
 | |
| }
 | |
| 
 | |
| bool PamInstance::fetch_anon_proxy_users(SERVER* server, MYSQL* conn)
 | |
| {
 | |
|     bool success = true;
 | |
|     const char ANON_USER_QUERY[] = "SELECT host,authentication_string FROM mysql.user WHERE "
 | |
|                                    "(plugin = 'pam' AND user = '');";
 | |
| 
 | |
|     const char GRANT_PROXY[] = "GRANT PROXY ON";
 | |
| 
 | |
|     // Query for the anonymous user which is used with group mappings
 | |
|     if (mysql_query(conn, ANON_USER_QUERY))
 | |
|     {
 | |
|         MXS_ERROR("Failed to query server '%s' for anonymous PAM users: '%s'.",
 | |
|                   server->name(), mysql_error(conn));
 | |
|         success = false;
 | |
|     }
 | |
|     else
 | |
|     {
 | |
|         // Temporary storage of host,authentication_string for anonymous pam users.
 | |
|         std::vector<std::pair<string, string>> anon_users_info;
 | |
|         MYSQL_RES* res = mysql_store_result(conn);
 | |
|         if (res)
 | |
|         {
 | |
|             MYSQL_ROW row;
 | |
|             while ((row = mysql_fetch_row(res)))
 | |
|             {
 | |
|                 string host = row[0] ? row[0] : "";
 | |
|                 string auth_str = row[1] ? row[1] : "";
 | |
|                 anon_users_info.push_back(std::make_pair(host, auth_str));
 | |
|             }
 | |
|             mysql_free_result(res);
 | |
|         }
 | |
| 
 | |
|         if (!anon_users_info.empty())
 | |
|         {
 | |
|             MXS_INFO("Found %lu anonymous PAM user(s). Checking them for proxy grants.",
 | |
|                      anon_users_info.size());
 | |
|         }
 | |
| 
 | |
|         for (const auto& elem : anon_users_info)
 | |
|         {
 | |
|             string query = "SHOW GRANTS FOR ''@'" + elem.first + "';";
 | |
|             // Check that the anon user has a proxy grant.
 | |
|             if (mysql_query(conn, query.c_str()))
 | |
|             {
 | |
|                 MXS_ERROR("Failed to query server '%s' for grants of anonymous PAM user ''@'%s': '%s'.",
 | |
|                           server->name(), elem.first.c_str(), mysql_error(conn));
 | |
|                 success = false;
 | |
|             }
 | |
|             else
 | |
|             {
 | |
|                 if ((res = mysql_store_result(conn)))
 | |
|                 {
 | |
|                     // The user may have multiple proxy grants, but is only added once.
 | |
|                     MYSQL_ROW row;
 | |
|                     while ((row = mysql_fetch_row(res)))
 | |
|                     {
 | |
|                         if (row[0] && strncmp(row[0], GRANT_PROXY, sizeof(GRANT_PROXY) - 1) == 0)
 | |
|                         {
 | |
|                             add_pam_user("", elem.first.c_str(),    // user, host
 | |
|                                          NULL, false,               // Unused
 | |
|                                          elem.second.c_str(), true);// service, proxy
 | |
|                             break;
 | |
|                         }
 | |
|                     }
 | |
|                     mysql_free_result(res);
 | |
|                 }
 | |
|             }
 | |
|         }
 | |
|     }
 | |
| 
 | |
|     return success;
 | |
| }
 | 
