0x00来源
解压自snortrules-snapshot-2975.tar.gz，来自于<解压目录>/etc/
classification.config
reference.config
sid-msg.map
snort.conf
threshold.conf
unicode.map
将这些.conf和.map文件放在/etc/snort 目录下，具体的请看 CentOS6.6下基于snort+barnyard2+base的入侵检测系统的搭建
0x01文件头翻译
# $Id: classification.config,v 1.14 2011/06/08 00:33:04 jjordan Exp $
# The following includes information for prioritizing rules
# 下面的内容包括了“优先”规则的信息
#
# Each classification includes a shortname, a description, and a default
# priority for that classification.
# 每个类别都有简称，描述，默认优先级。
# This allows alerts to be classified and prioritized. You can specify
# what priority each classification has. Any rule can override the default
# priority for that rule.
# 这种方式使得告警可以被分类和优先选择。你可以指定每个分类的优先级。任何规则都可以重写这些
# 默认的优先级。
# Here are a few example rules:
#
# alert TCP any any -> any 80 (msg: "EXPLOIT ntpdx overflow";
# dsize: > 128; classtype:attempted-admin; priority:10;
#
# alert TCP any any -> any 25 (msg:"SMTP expn root"; flags:A+; \
# content:"expn root"; nocase; classtype:attempted-recon;)
#
# The first rule will set its type to "attempted-admin" and override
# the default priority for that type to 10.
# 第一个规则被分在"attempted-admin"类，并且重写了默认优先级。
# The second rule set its type to "attempted-recon" and set its
# priority to the default for that type.
# 第二个规则被分在"attempted-recon"类，采用了此类别默认的优先级。
#
# config classification:shortname,short description,priority
# 用以上格式书写
0x02 修饰符
此文件对应的修饰符是classtype。查看manual可知，此关键字的作用为了将告警分类。
举个例子。
alert tcp any any -> any 25 (msg:"SMTP expn root"; flags:A+; content:"expn root"; nocase; classtype:attempted-recon;)
classtype必须在classification.config文件中才可以使用，如果想自定义，可以自行修改clssfication.config文件。
0x03 数据库
classtype对应着数据库中的sig_class表，全称写出来更好理解一点，signature_classification。
通过这里我们了解到snort数据库的ER图，sig这部分的如下：
sig三张表
mysql> desc sig_class
-> ;
+----------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+----------------+------------------+------+-----+---------+----------------+
| sig_class_id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| sig_class_name | varchar(60) | NO | MUL | NULL | |
+----------------+------------------+------+-----+---------+----------------+
2 rows in set (0.07 sec)
mysql> select * from sig_class;
+--------------+-----------------+
| sig_class_id | sig_class_name |
+--------------+-----------------+
| 1 | attempted-admin |
| 2 | misc-attack |
+--------------+-----------------+
2 rows in set (0.00 sec)
sig_class表中就两列，sig_class_id是分类的ID（应该是递增的），sig_class_name是分类的名称。
mysql> desc signature;
+--------------+------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------------+------+-----+---------+----------------+
| sig_id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| sig_name | varchar(255) | NO | MUL | NULL | |
| sig_class_id | int(10) unsigned | NO | MUL | NULL | |
| sig_priority | int(10) unsigned | YES | | NULL | |
| sig_rev | int(10) unsigned | YES | | NULL | |
| sig_sid | int(10) unsigned | YES | | NULL | |
| sig_gid | int(10) unsigned | YES | | NULL | |
+--------------+------------------+------+-----+---------+----------------+
7 rows in set (0.04 sec)
mysql> select * from signature;
+--------+--------------------------------+--------------+--------------+---------+---------+---------+
| sig_id | sig_name | sig_class_id | sig_priority | sig_rev | sig_sid | sig_gid |
+--------+--------------------------------+--------------+--------------+---------+---------+---------+
| 8 | Snort Alert [1:1000011:0] | 0 | NULL | 1 | 1000011 | 1 |
| 9 | PROTOCOL-ICMP PACKAGE DETECTED | 0 | NULL | 1 | 1000011 | 1 |
+--------+--------------------------------+--------------+--------------+---------+---------+---------+
2 rows in set (0.00 sec)
从上面我们可以看到两张表中，sig_class的主键是sig_class_id，signature表的主键是sig_id，外键是sig_class_id。
