如何为openvpn fail2ban过滤器创建正则表达式

Question

有些人想进入我的openvpn服务器。现在，我手动禁止每个I，因为我不知道如何设置fail2ban正则表达式。下面的内容基本上是在我的/var/log/syslog中找到的

Jun 18 19:57:01 Server ovpn-openvpn_tcp[856]: TCP connection established with [AF_INET]196.52.43.65:6666
Jun 18 19:57:03 Server ovpn-openvpn_tcp[856]: 196.52.43.65:6666 WARNING: Bad encapsulated packet length from peer (5635), which must be > 0 and <= 1627 -- please ensure that --tun-mtu or --link-mtu is equal on both peers -- this condition could also indicate a possible active attack on the TCP link -- [Attempting restart...]
Jun 18 19:57:03 Server ovpn-openvpn_tcp[856]: 196.52.43.65:6666 Connection reset, restarting [0]
Jun 18 19:57:03 Server ovpn-openvpn_tcp[856]: 196.52.43.65:6666 SIGUSR1[soft,connection-reset] received, client-instance restarting
Jun 18 20:42:20 Server ovpn-openvpn_tcp[856]: TCP connection established with [AF_INET]23.239.65.138:61397
Jun 18 20:42:20 Server ovpn-openvpn_tcp[856]: 23.239.65.138:61397 WARNING: Bad encapsulated packet length from peer (5635), which must be > 0 and <= 1627 -- please ensure that --tun-mtu or --link-mtu is equal on both peers -- this condition could also indicate a possible active attack on the TCP link -- [Attempting restart...]
Jun 18 20:42:20 Server ovpn-openvpn_tcp[856]: 23.239.65.138:61397 Connection reset, restarting [0]
Jun 18 20:42:20 Server ovpn-openvpn_tcp[856]: 23.239.65.138:61397 SIGUSR1[soft,connection-reset] received, client-instance restarting

我试图按照openvpn的官方fail2ban指南创建一个过滤器，但是我认为它已经过时了，并且在运行一些测试之后不能正确地解析。导游让我做以下几件事：

#Fail2Ban filter for selected OpenVPN rejections 

[Definition]

# Example messages (other matched messages not seen in the testing server's logs):
# Fri Sep 23 11:55:36 2016 TLS Error: incoming packet authentication failed from [AF_INET]59.90.146.160:51223
# Thu Aug 25 09:36:02 2016 117.207.115.143:58922 TLS Error: TLS handshake failed

failregex = ^ TLS Error: incoming packet authentication failed from \[AF_INET\]:\d+$
            ^ :\d+ Connection reset, restarting
            ^ :\d+ Fatal TLS Error
            ^ :\d+ TLS Error: TLS handshake failed$
            ^ :\d+ VERIFY ERROR
            ^ :\d+ Bad encapsulated packet length

ignoreregex =

这在我的jail.local文件中：

[openvpndeny]

enabled  = true
port     = 443
protocol = tcp
filter   = openvpndeny
logpath  =  /var/log/syslog
maxretry = 3

不幸的是，在运行fail2ban-regex /var/log/syslog /etc/fail2ban/filter.d/openvpndeny.conf之后，我得到了下面的输出

Running tests
=============

Use   failregex filter file : openvpndeny, basedir: /etc/fail2ban
Use         log file : /var/log/syslog
Use         encoding : UTF-8


Results
=======

Failregex: 0 total

Ignoreregex: 0 total

Date template hits:
|- [# of hits] date format
|  [4608] (?:DAY )?MON Day 24hour:Minute:Second(?:\.Microseconds)?(?: Year)?
`-

Lines: 4608 lines, 0 ignored, 0 matched, 4608 missed
[processed in 3.78 sec]

Missed line(s): too many to print.  Use --print-all-missed to print all 4608 lines

我今天开始学习如何使用正则表达式，因为我已经在堆栈溢出中询问过了，没有人能真正帮助我。我不知道fail2ban是如何定义来获取IP的。我试着用我自己的方式得到I，做一个这样的过滤器：

(\d+\.\d+\.\d+\.\d+:\d+ Connection reset, restarting) --它在https://regex101.com/中工作，但不使用fail2ban。

Answer 1

在学习了更多关于regex的知识之后，我能够为fail2ban创建这样一个过滤器

[Definition]

failregex = :\d+ (Connection reset, restarting|TLS Error: TLS handshake failed|Fatal TLS error|VERIFY ERROR|WARNING: Bad encapsulated packet length)
ignoreregex =