MDEV-9245 password "reuse prevention" validation plugin

mysql-test/suite/plugins/r/password_reuse_check.result

+install soname "password_reuse_check";
+set global password_reuse_check_interval= 0;
+# Default value (sould be unlimited i.e. 0)
+SHOW GLOBAL VARIABLES like "password_reuse_check%";
+Variable_name	Value
+password_reuse_check_interval	0
+# insert user
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+ERROR HY000: Your password does not satisfy the current policy requirements
+show warnings;
+Level	Code	Message
+Error	1819	Your password does not satisfy the current policy requirements
+alter user user_name@localhost identified by 'test_pwd';
+ERROR HY000: Operation ALTER USER failed for 'user_name'@'localhost'
+show warnings;
+Level	Code	Message
+Error	1819	Your password does not satisfy the current policy requirements
+Error	1396	Operation ALTER USER failed for 'user_name'@'localhost'
+# check exparation
+set global password_reuse_check_interval= 10;
+alter user user_name@localhost identified by 'test_pwd';
+ERROR HY000: Operation ALTER USER failed for 'user_name'@'localhost'
+show warnings;
+Level	Code	Message
+Error	1819	Your password does not satisfy the current policy requirements
+Error	1396	Operation ALTER USER failed for 'user_name'@'localhost'
+select hex(hash) from mysql.password_reuse_check_history;
+hex(hash)
+6276C87127F2B65FC6B24E94E324A02FF0D393D7FB7DEAF6F5F49F0A8AB006711D5C6EF67E36A251AB6337E7E20D312F9ED66D70EB699A6EC85B1E0BC7F376C0
+# emulate old password
+update mysql.password_reuse_check_history set time= date_sub(now(), interval
+11 day);
+alter user user_name@localhost identified by 'test_pwd';
+show warnings;
+Level	Code	Message
+drop user user_name@localhost;
+show create table mysql.password_reuse_check_history;
+Table	Create Table
+password_reuse_check_history	CREATE TABLE `password_reuse_check_history` (
+  `hash` binary(64) NOT NULL,
+  `time` timestamp NOT NULL DEFAULT current_timestamp(),
+  PRIMARY KEY (`hash`),
+  KEY `tm` (`time`)
+) ENGINE=Aria DEFAULT CHARSET=latin1 PAGE_CHECKSUM=1
+select count(*) from mysql.password_reuse_check_history;
+count(*)
+1
+drop table mysql.password_reuse_check_history;
+# test error messages
+set global password_reuse_check_interval= 0;
+drop table if exists mysql.password_reuse_check_history;
+Warnings:
+Note	1051	Unknown table 'mysql.password_reuse_check_history'
+# test error messages
+create table mysql.password_reuse_check_history (wrong_structure int);
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+ERROR HY000: Your password does not satisfy the current policy requirements
+show warnings;
+Level	Code	Message
+Warning	1105	password_reuse_check:[1054] Unknown column 'hash' in 'field list'
+Error	1819	Your password does not satisfy the current policy requirements
+set global password_reuse_check_interval= 10;
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+ERROR HY000: Your password does not satisfy the current policy requirements
+show warnings;
+Level	Code	Message
+Warning	1105	password_reuse_check:[1054] Unknown column 'time' in 'where clause'
+Error	1819	Your password does not satisfy the current policy requirements
+drop table mysql.password_reuse_check_history;
+uninstall plugin password_reuse_check;

mysql-test/suite/plugins/t/password_reuse_check.test

+--source include/not_embedded.inc
+
+if (!$PASSWORD_REUSE_CHECK_SO) {
+  skip No PASSWORD_REUSE_CHECK plugin;
+}
+
+install soname "password_reuse_check";
+
+set global password_reuse_check_interval= 0;
+
+--echo # Default value (sould be unlimited i.e. 0)
+SHOW GLOBAL VARIABLES like "password_reuse_check%";
+
+--echo # insert user
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+
+--error ER_NOT_VALID_PASSWORD
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+show warnings;
+
+--error ER_CANNOT_USER
+alter user user_name@localhost identified by 'test_pwd';
+show warnings;
+
+# Plugin does not work for it
+#--error ER_NOT_VALID_PASSWORD
+#SET PASSWORD FOR user_name@localhost = PASSWORD('test_pwd');
+
+--echo # check exparation
+
+set global password_reuse_check_interval= 10;
+
+--error ER_CANNOT_USER
+alter user user_name@localhost identified by 'test_pwd';
+show warnings;
+select hex(hash) from mysql.password_reuse_check_history;
+
+--echo # emulate old password
+update mysql.password_reuse_check_history set time= date_sub(now(), interval
+11 day);
+
+alter user user_name@localhost identified by 'test_pwd';
+show warnings;
+
+drop user user_name@localhost;
+
+show create table mysql.password_reuse_check_history;
+select count(*) from mysql.password_reuse_check_history;
+
+drop table mysql.password_reuse_check_history;
+
+--echo # test error messages
+
+set global password_reuse_check_interval= 0;
+
+drop table if exists mysql.password_reuse_check_history;
+
+--echo # test error messages
+
+create table mysql.password_reuse_check_history (wrong_structure int);
+
+--error ER_NOT_VALID_PASSWORD
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+show warnings;
+
+set global password_reuse_check_interval= 10;
+
+--error ER_NOT_VALID_PASSWORD
+grant select on *.* to user_name@localhost identified by 'test_pwd';
+show warnings;
+
+drop table mysql.password_reuse_check_history;
+uninstall plugin password_reuse_check;

plugin/password_reuse_check/CMakeLists.txt

+
+MYSQL_ADD_PLUGIN(password_reuse_check password_reuse_check.c)

plugin/password_reuse_check/password_reuse_check.c

+/* Copyright (c) 2021, Oleksandr Byelkin and MariaDB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program 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 this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335  USA */
+
+#include <stdio.h>     // for snprintf
+#include <string.h>    // for memset
+#include <mysql/plugin_password_validation.h>
+#include <mysqld_error.h>
+
+#define HISTORY_DB_NAME "password_reuse_check_history"
+
+#define SQL_BUFF_LEN 2048
+
+#define STRING_WITH_LEN(X) (X), ((size_t) (sizeof(X) - 1))
+
+// 0 - unlimited, otherwise number of days to check
+static unsigned interval= 0;
+
+// helping string for bin_to_hex512
+static char digits[]= "0123456789ABCDEF";
+
+
+/**
+  Convert string of 512 bits (64 bytes) to hex representation
+
+  @param to              pointer to the result puffer
+                         (should be at least 64*2 bytes)
+  @param str             pointer to 512 bits (64 bytes string)
+*/
+
+static void bin_to_hex512(char *to, const unsigned char *str)
+{
+  const unsigned char *str_end= str + (512/8);
+  for (; str != str_end; ++str)
+  {
+    *to++= digits[((unsigned char) *str) >> 4];
+    *to++= digits[((unsigned char) *str) & 0x0F];
+  }
+}
+
+
+/**
+  Send SQL error as ER_UNKNOWN_ERROR for information
+
+  @param mysql           Connection handler
+*/
+
+static void report_sql_error(MYSQL *mysql)
+{
+  my_printf_error(ER_UNKNOWN_ERROR, "password_reuse_check:[%d] %s", ME_WARNING,
+                  mysql_errno(mysql), mysql_error(mysql));
+}
+
+
+/**
+  Create the history of passwords table for this plugin.
+
+  @param mysql           Connection handler
+
+  @retval 1 - Error
+  @retval 0 - OK
+*/
+
+static int create_table(MYSQL *mysql)
+{
+  if (mysql_real_query(mysql,
+        // 512/8 = 64
+        STRING_WITH_LEN("CREATE TABLE mysql." HISTORY_DB_NAME
+                        " ( hash binary(64),"
+                        " time timestamp default current_timestamp,"
+                        " primary key (hash), index tm (time) )"
+                        " ENGINE=Aria")))
+  {
+    report_sql_error(mysql);
+    return 1;
+  }
+  return 0;
+}
+
+
+/**
+  Run this query and create table if needed
+
+  @param mysql           Connection handler
+  @param query           The query to run
+  @param len             length of the query text
+
+  @retval 1 - Error
+  @retval 0 - OK
+*/
+
+static int run_query_with_table_creation(MYSQL *mysql, const char *query,
+                                         size_t len)
+{
+  if (mysql_real_query(mysql, query, len))
+  {
+    unsigned int rc= mysql_errno(mysql);
+    if (rc != ER_NO_SUCH_TABLE)
+    {
+      // suppress this error in case of try to add the same password twice
+      if (rc != ER_DUP_ENTRY)
+        report_sql_error(mysql);
+      return 1;
+    }
+    if (create_table(mysql))
+      return 1;
+    if (mysql_real_query(mysql, query, len))
+    {
+      report_sql_error(mysql);
+      return 1;
+    }
+  }
+  return 0;
+}
+
+
+/**
+  Password validator
+
+  @param username        User name (part of whole login name)
+  @param password        Password to validate
+  @param hostname        Host name (part of whole login name)
+
+  @retval 1 - Password is not OK or an error happened
+  @retval 0 - Password is OK
+*/
+
+static int validate(const MYSQL_CONST_LEX_STRING *username,
+                    const MYSQL_CONST_LEX_STRING *password,
+                    const MYSQL_CONST_LEX_STRING *hostname)
+{
+  MYSQL *mysql= NULL;
+  size_t key_len= username->length + password->length + hostname->length;
+  size_t buff_len= (key_len > SQL_BUFF_LEN ? key_len : SQL_BUFF_LEN);
+  size_t len;
+  char *buff= malloc(buff_len);
+  unsigned char hash[512/8];
+  char escaped_hash[512/8*2 + 1];
+  if (!buff)
+    return 1;
+
+  mysql= mysql_init(NULL);
+  if (!mysql)
+  {
+    free(buff);
+    return 1;
+  }
+
+  memcpy(buff, hostname->str, hostname->length);
+  memcpy(buff + hostname->length, username->str, username->length);
+  memcpy(buff + hostname->length + username->length, password->str,
+          password->length);
+  buff[key_len]= 0;
+  memset(hash, 0, sizeof(hash));
+  my_sha512(hash, buff, key_len);
+  if (mysql_real_connect_local(mysql) == NULL)
+    goto sql_error;
+
+  if (interval)
+  {
+    // trim the table
+    len= snprintf(buff, buff_len,
+                  "DELETE FROM mysql." HISTORY_DB_NAME
+                  " WHERE time < DATE_SUB(NOW(), interval %d day)",
+                  interval);
+    if (run_query_with_table_creation(mysql, buff, len))
+      goto sql_error;
+  }
+
+  bin_to_hex512(escaped_hash, hash);
+  escaped_hash[512/8*2]= '\0';
+  len= snprintf(buff, buff_len,
+                "INSERT INTO mysql." HISTORY_DB_NAME "(hash) "
+                "values (x'%s')",
+                escaped_hash);
+  if (run_query_with_table_creation(mysql, buff, len))
+    goto sql_error;
+
+  free(buff);
+  mysql_close(mysql);
+  return 0; // OK
+
+sql_error:
+  free(buff);
+  if (mysql)
+    mysql_close(mysql);
+  return 1; // Error
+}
+
+static MYSQL_SYSVAR_UINT(interval, interval, PLUGIN_VAR_RQCMDARG,
+  "Password history retention period in days (0 means unlimited)", NULL, NULL,
+  0, 0, 365*100, 1);
+
+
+static struct st_mysql_sys_var* sysvars[]= {
+  MYSQL_SYSVAR(interval),
+  NULL
+};
+
+static struct st_mariadb_password_validation info=
+{
+  MariaDB_PASSWORD_VALIDATION_INTERFACE_VERSION,
+  validate
+};
+
+maria_declare_plugin(password_reuse_check)
+{
+  MariaDB_PASSWORD_VALIDATION_PLUGIN,
+  &info,
+  "password_reuse_check",
+  "Oleksandr Byelkin",
+  "Prevent password reuse",
+  PLUGIN_LICENSE_GPL,
+  NULL,
+  NULL,
+  0x0100,
+  NULL,
+  sysvars,
+  "1.0",
+  MariaDB_PLUGIN_MATURITY_ALPHA
+}
+maria_declare_plugin_end;