MySQL-audit审计插件

审计功能

官方收费组件需购买企业版才可以使用审计功能。

下面通过第三方开源审计插件libaudit_plugin.so完成审计功能。

安装配置

软件下载地址

查看插件目录

show variables like 'plugin_dir';

解压软件

将上面下载到对应版本解压到plugin目录

unzip -qo /tmp/audit-plugin-mysql-5.6-1.1.6-784-linux-x86_64.zip -d /ups/app/mysql/mysql/lib/plugin/

修改文件权限

chown mysql:mysql /ups/app/mysql/lib/plugin/libaudit_plugin.so
chmod +x /ups/app/mysql/lib/plugin/libaudit_plugin.so

数据库层面配置

install plugin audit soname 'libaudit_plugin.so';

error日志输出

检查插件安装配置情况

show plugins;
show global status like '%audit%';

卸载插件

set audit_uninstall_plugin=on;
uninstall plugin AUDIT;

需要在 my.cnf 中 [mysqld] 下添加 audit_uninstall_plugin=1，重启mysql。重启完毕后执行两次 UNINSTALL PLUGIN AUDIT; 即可卸载

卸载完成后需要从 my.cnf 中删除 audit_uninstall_plugin=1

使用

开启audit审计功能

SET GLOBAL audit_json_file=ON;
SHOW GLOBAL VARIABLES LIKE '%audi%'; 

附录

安装过程遇到offsets问题

背景描述

error日志中抛出如下信息导致插件安装失败：

[ERROR] McAfee Audit Plugin: Offsets: 5.6.36 (ef258e946d486d6f67a679b3c794b1fc) match thread validation check fails with value: 0. Skipping offset

处理过程

参考文档

下载脚本

#!/bin/sh

if [ $# = 0 ]
then 	
	echo "Usage: $0 <mysqld executable> [optional mysqld symbols]"
	echo "Will extract offsets from mysqld. Requires gdb, md5sum and mysqld symbols."
	exit 1
fi

# Extract the version of mysqld

FULL_MYVER=`$1 --version | grep -P -o 'Vers+[w.-]+'| awk '{ print $2 }'`

# Extract the md5 digest

MYMD5=`md5sum -b $1 | awk -v Field=1 '{ print $1 }'`

MYVER="$FULL_MYVER"
if echo $FULL_MYVER | grep  'log' > /dev/null
then
	MYVER=`echo "$MYVER" | grep -P -o '.+(?=-log)'`
fi

COMMAND_MEMBER=command
THREAD_ID=thread_id
SEC_CONTEXT=main_security_ctx
USER=user
HOST=host
IP=ip
PRIV_USER=priv_user
DB=db
CLIENT_CAPS="print_offset THD client_capabilities"

# In 5.6 command member is named m_command
if echo $MYVER | grep -P '^(5.6|5.7|10.)' > /dev/null
then
	COMMAND_MEMBER=m_command
	HAS_CONNECT_ATTRS=yes
fi

CONNECT_ATTRS_CS=m_session_connect_attrs_cs
# In 5.7 thread_id changed to m_thread_id. main_security_ctx changed to m_main_security_ctx
if echo $MYVER | grep -P '^(5.7)' > /dev/null
then
	THREAD_ID=m_thread_id
	SEC_CONTEXT=m_main_security_ctx
	USER=m_user
	HOST=m_host
	IP=m_ip
	PRIV_USER=m_priv_user    
	DB=m_db
	# client capabilities has moved out THD in 5.7. Set to 0
	CLIENT_CAPS='print_offset THD m_protocol'      

	# comment which holds plugin name for uninstall moved into
	# a separate object
	HAS_LEX_SQL_CMD=yes
fi

# In 5.6.15 and up, 5.7 and mariabdb 10.0.11 and up, mariadb 10.1 
# m_session_connect_attrs_cs changed to m_session_connect_attrs_cs_number
if echo $MYVER | grep -P '^(5.7|10.[1-2]|5.6.(1[5-9]|[2-9][0-9])|10.0.(1[1-9]|[2-9][0-9]))' > /dev/null
then
	CONNECT_ATTRS_CS=m_session_connect_attrs_cs_number
fi

CONNECT_ATTRS=""
if [ -n "$HAS_CONNECT_ATTRS" ]
then  
	CONNECT_ATTRS="print_offset PFS_thread m_session_connect_attrs
print_offset PFS_thread m_session_connect_attrs_length
print_offset PFS_thread $CONNECT_ATTRS_CS
"
else
	CONNECT_ATTRS='printf ", 0, 0, 0"'
fi

if echo $MYVER | grep -P '^5.7' > /dev/null
then
	if echo $MYVER | grep -P '^5.7.8' > /dev/null
	then
		FOUND_ROWS="print_offset THD limit_found_rows"
	else
		FOUND_ROWS="print_offset THD previous_found_rows"
	fi
else
	FOUND_ROWS="print_offset THD limit_found_rows"
fi

if echo $MYVER | grep -P '^5.[15]' > /dev/null
then
	SENT_ROW_COUNT='print_offset THD sent_row_count'
else
	SENT_ROW_COUNT="print_offset THD m_sent_row_count"
fi

if echo $MYVER | grep -P '^5.1' > /dev/null
then
	ROW_COUNT_FUNC='print_offset THD row_count_func'
else
	ROW_COUNT_FUNC='print_offset THD m_row_count_func'
fi

LEX_SQL=""
if [ -n "$HAS_LEX_SQL_CMD" ]
then
	LEX_SQL="print_offset LEX m_sql_cmd
print_offset Sql_cmd_uninstall_plugin m_comment"
else
	LEX_SQL='printf ", 0, 0"'
fi

# Exit status info 5.5, 5.6, 5.7
DA_STATUS="print_offset Diagnostics_area m_status"		# 5.5, 5.6, 5.7, mariadb 10.0, 10.1, 10.2
DA_SQL_ERRNO="print_offset Diagnostics_area m_sql_errno"	# 5.5, 5.6, mariadb 10.0, 10.1, 10.2
STMT_DA="print_offset THD m_stmt_da"				# 5.6, 5.7, mariadb 10.0, 10.1, 10.2

if echo $MYVER | grep -P '^(5.7)' > /dev/null
then
	DA_SQL_ERRNO="print_offset Diagnostics_area m_mysql_errno"
elif echo $MYVER | grep -P '^(5.6|10.)' > /dev/null
then
	: place holder
elif echo $MYVER | grep -P '^(5.5)' > /dev/null
then
	STMT_DA="print_offset THD stmt_da"
else
	STMT_DA='printf ", 0"'
	DA_STATUS='printf ", 0"'
	DA_SQL_ERRNO='printf ", 0"'
fi

cat <<EOF > offsets.gdb
set logging on
set width 0
define print_offset
  printf ", %d", (size_t)&(($arg0*)0)->$arg1
end
printf "{"$MYVER","$MYMD5""
print_offset THD query_id
print_offset THD $THREAD_ID
print_offset THD $SEC_CONTEXT
print_offset THD $COMMAND_MEMBER
print_offset THD lex
print_offset LEX comment
print_offset Security_context $USER
print_offset Security_context $HOST
print_offset Security_context $IP
print_offset Security_context $PRIV_USER
print_offset THD $DB
print_offset THD killed
$CLIENT_CAPS
$CONNECT_ATTRS
print_offset THD net
$LEX_SQL
$FOUND_ROWS
$SENT_ROW_COUNT
$ROW_COUNT_FUNC
$STMT_DA
$DA_STATUS
$DA_SQL_ERRNO
printf "}"
EOF

SYMPARAM=""
if [ -n "$2" ]
then
	SYMPARAM="-s $2 -e"
fi

if which gdb > /dev/null 2>&1
then
	:
else
        echo "ERROR: gdb not found. Make sure gdb is installed and on the path."
        exit 3
fi

if gdb -n -q -batch -x offsets.gdb $SYMPARAM  $1 > /dev/null 2>&1
then
	:
else
	echo "GDB failed!!!" > /dev/stderr
	exit 2
fi

OFFSETS=`cat gdb.txt`
echo "//offsets for: $1 ($FULL_MYVER)"
echo "$OFFSETS,"

# clean up
rm gdb.txt
rm offsets.gdb

安装gdb

yum -y install gdb

执行脚本

chmod +x offset-extract.sh
./offset-extract.sh /ups/app/mysql/bin/mysqld  #(mysqld路径)

修改my.cnf中的[mysqld]增加上一步输出配置

vi /etc/my.cnf
[mysqld]
plugin-load=AUDIT=libaudit_plugin.so
audit_offsets=6976, 7024, 3984, 4504, 72, 2704, 96, 0, 32, 104, 136, 7112, 4376, 2800, 2808, 2812, 528, 0, 0, 6344, 6368, 6352, 13024, 548, 516

重启mysqld服务

再次重新安装audit插件即可