我的Fail2Ban过滤器似乎无法正常工作

Question

我正在尝试使用fail2ban-regex命令测试我的过滤器和正则表达式，但似乎没有任何运气。 我使用了一个教程来演示如何将Devise gem与Rails一起使用来记录失败的登录。

这是我的/etc/fail2ban/filter.d/core.conf文件：

[INCLUDES]
before = common.conf

[Definition]
failregex = ^\s*(\[.+?\] )*Failed login for '.*' from <HOST> at $

然后是我的/etc/fail2ban/jail.conf文件中的内容。

[core]
enabled = true
filter  = core
port    = http,https
logpath = /home/rails/Documents/rails_app/devise.log
bantime = 3600
findtime = 600
maxretry = 2

这是Rails创建的devise.log文件的示例输出：

# Logfile created on 2018-09-26 16:19:41 -0500 by logger.rb/61378
E, [2018-09-26T16:19:41.353620 #12157] ERROR -- : Failed login for 'ekjtherkjh@gmail.com' from 172.16.38.1 at 2018-09-26T21:19:41Z
E, [2018-09-26T16:27:17.469743 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:17Z
E, [2018-09-26T16:27:19.706783 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:19Z
E, [2018-09-26T16:27:21.504956 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:21Z
E, [2018-09-26T16:27:23.193147 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:23Z

这正是本教程中使用的内容。 但是，当我提交无效的登录尝试时，没有任何反应。

这是我的fail2ban-regex命令的结果：

[myuser:ubuntu:/etc/fail2ban/filter.d]$ fail2ban-regex /home/rails/Documents/rails_app/devise.log "^\s*(\[.+?\] )*Failed login for '.*' from <HOST> at $"

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

Use   failregex line : ^\s*(\[.+?\] )*Failed login for '.*' from <HOST> at $
Use         log file : /home/rails/Documents/rails_app/devise.log
Use         encoding : UTF-8


Results
=======

Failregex: 0 total

Ignoreregex: 0 total

Date template hits:
|- [# of hits] date format
|  [13] ExYear(?P<_sep>[-/.])Month(?P=_sep)Day(?:T|  ?)24hour:Minute:Second(?:[.,]Microseconds)?(?:\s*Zone offset)?
`-

Lines: 13 lines, 0 ignored, 0 matched, 13 missed
[processed in 0.02 sec]

|- Missed line(s):
|  E, [2018-09-26T16:19:41.353620 #12157] ERROR -- : Failed login for 'ekjtherkjh@gmail.com' from 172.16.38.1 at 2018-09-26T21:19:41Z
|  E, [2018-09-26T16:27:17.469743 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:17Z
|  E, [2018-09-26T16:27:19.706783 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:19Z
|  E, [2018-09-26T16:27:21.504956 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:21Z
|  E, [2018-09-26T16:27:23.193147 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:23Z
|  E, [2018-09-26T16:27:24.959032 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:24Z
|  E, [2018-09-26T16:27:26.661292 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:26Z
|  E, [2018-09-26T16:27:28.297408 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:28Z
|  E, [2018-09-26T16:27:30.179503 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:30Z
|  E, [2018-09-26T16:27:31.940616 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:31Z
|  E, [2018-09-26T16:32:42.579173 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:32:42Z
|  E, [2018-09-26T16:32:44.817088 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:32:44Z
|  E, [2018-09-26T16:32:46.660918 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:32:46Z

不知道为什么这不起作用。 有任何偶然的建议吗？ 我试图操纵我的正则表达式，但还是没有运气。

编辑

从字面上看，似乎Fail2Ban已损坏，或者我只是完全搞砸了正则表达式。 我将devise.log文件缩小为包含IP地址的一行，并将过滤器缩小为：

[INCLUDES]
before = common.conf

[Definition]
failregex = <HOST>

而且它仍然找不到IP地址：

[myuser:ubuntu:/etc/fail2ban/filter.d]$ fail2ban-regex /home/rails/Documents/rails_app/devise.log core.conf

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

Use   failregex filter file : core, basedir: /etc/fail2ban
Use      datepattern : Default Detectors
Use         log file : /home/rails/Documents/rails_app/devise.log
Use         encoding : UTF-8


Results
=======

Failregex: 0 total

Ignoreregex: 0 total

Date template hits:

Lines: 1 lines, 0 ignored, 0 matched, 1 missed
[processed in 0.01 sec]

|- Missed line(s):
|  172.16.38.1
`-

Answer 1

在您的日志中，您的行看起来像这样：

E, [2018-09-26T16:27:17.469743 #12157] ERROR -- : Failed login for 'kjelkjer@gmail.com' from 172.16.38.1 at 2018-09-26T21:27:17Z

而您的正则表达式缺少这部分的结尾：行尾的2018-09-26T21：27：17Z 因此，您需要按以下方式修改正则表达式：

failregex = ^.* (\[.*\])* ERROR -- \: Failed login for '.*' from <HOST> at .*$

在这里您可以测试您的正则表达式。 只记得在正则表达式站点上用\\d+\\.\\d+\\.\\d+\\.\\d+替换<HOST> ，然后在conf文件中返回<HOST> 。

让我知道是否有帮助。