如何在 Debian 中配置 Tripewire IDS

本文是一篇关于 Debian 中安装和配置 tripewire 的文章。它是 Linux 环境下基于主机的入侵检测系统（IDS）。tripwire 的高级功能可以检测并报告任何 Linux 中未授权的（文件和目录）的更改。tripewire 安装之后，会先创建一个基本的数据库，tripewire 监控并检测新文件的创建修改和谁修改了它等等。如果修改是合法的，你可以接受修改并更新 tripwire 的数据库。

安装和配置

tripwire 在 Debian VM 中的安装如下。

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# apt-get install tripwire

installation

安装中，tripwire 会有下面的配置提示。

站点密钥创建

tripwire 需要一个站点口令（site passphrase）来加密 tripwire 的配置文件 tw.cfg 和策略文件 tw.pol。tripewire 使用指定的密码加密两个文件。一个 tripewire 实例必须指定站点口令。

site key1

本地密钥口令

本地口令用来保护 tripwire 数据库和报告文件。本地密钥用于阻止非授权的 tripewire 数据库修改。

local key1

tripwire 配置路径

tripewire 配置存储在 /etc/tripwire/twcfg.txt。它用于生成加密的配置文件 tw.cfg。

configuration file

tripwire 策略路径

tripwire 在 /etc/tripwire/twpol.txt 中保存策略文件。它用于生成加密的策略文件 tw.pol。

tripwire policy

安装完成后如下图所示。

installed tripewire1

tripwire 配置文件 (twcfg.txt)

tripewire 配置文件（twcfg.txt）细节如下图所示。加密策略文件（tw.pol）、站点密钥（site.key）和本地密钥（hostname-local.key）在后面展示。

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ROOT         =/usr/sbin

POLFILE       =/etc/tripwire/tw.pol

DBFILE       =/var/lib/tripwire/$(HOSTNAME).twd

REPORTFILE   =/var/lib/tripwire/report/$(HOSTNAME)-$(DATE).twr

SITEKEYFILE   =/etc/tripwire/site.key

LOCALKEYFILE =/etc/tripwire/$(HOSTNAME)-local.key

EDITOR       =/usr/bin/editor

LATEPROMPTING =false

LOOSEDIRECTORYCHECKING =false

MAILNOVIOLATIONS =true

EMAILREPORTLEVEL =3

REPORTLEVEL   =3

SYSLOGREPORTING =true

MAILMETHOD   =SMTP

SMTPHOST     =localhost

SMTPPORT     =25

TEMPDIRECTORY =/tmp

tripwire 策略配置

在生成基础数据库之前先配置 tripwire 配置。有必要经用一些策略如 /dev、 /proc 、/root/mail 等。详细的 twpol.txt 策略文件如下所示。

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@@section GLOBAL
TWBIN = /usr/sbin;
TWETC = /etc/tripwire;
TWVAR = /var/lib/tripwire;

#
# File System Definitions
#
@@section FS

#
# First, some variables to make configuration easier
#
SEC_CRIT      = $(IgnoreNone)-SHa ; # Critical files that cannot change

SEC_BIN       = $(ReadOnly) ;        # Binaries that should not change

SEC_CONFIG    = $(Dynamic) ;         # Config files that are changed
# infrequently but accessed
# often

SEC_LOG       = $(Growing) ;         # Files that grow, but that
# should never change ownership

SEC_INVARIANT = +tpug ;              # Directories that should never
# change permission or ownership

SIG_LOW       = 33 ;                 # Non-critical files that are of
# minimal security impact

SIG_MED       = 66 ;                 # Non-critical files that are of
# significant security impact

SIG_HI        = 100 ;                # Critical files that are
# significant points of
# vulnerability

#
# tripwire Binaries
#
(
rulename = "tripwire Binaries",
severity = $(SIG_HI)
)
{
$(TWBIN)/siggen            -> $(SEC_BIN) ;
$(TWBIN)/tripwire        -> $(SEC_BIN) ;
$(TWBIN)/twadmin        -> $(SEC_BIN) ;
$(TWBIN)/twprint        -> $(SEC_BIN) ;
}
{
/boot            -> $(SEC_CRIT) ;
/lib/modules        -> $(SEC_CRIT) ;
}

(
rulename = "Boot Scripts",
severity = $(SIG_HI)
)
{
/etc/init.d        -> $(SEC_BIN) ;
#/etc/rc.boot        -> $(SEC_BIN) ;
/etc/rcS.d        -> $(SEC_BIN) ;
/etc/rc0.d        -> $(SEC_BIN) ;
/etc/rc1.d        -> $(SEC_BIN) ;
/etc/rc2.d        -> $(SEC_BIN) ;
/etc/rc3.d        -> $(SEC_BIN) ;
/etc/rc4.d        -> $(SEC_BIN) ;
/etc/rc5.d        -> $(SEC_BIN) ;
/etc/rc6.d        -> $(SEC_BIN) ;
}

(
rulename = "Root file-system executables",
severity = $(SIG_HI)
)
{
/bin            -> $(SEC_BIN) ;
/sbin            -> $(SEC_BIN) ;
}

#
# Critical Libraries
#
(
rulename = "Root file-system libraries",
severity = $(SIG_HI)
)
{
/lib            -> $(SEC_BIN) ;
}

#
# Login and Privilege Raising Programs
#
(
rulename = "Security Control",
severity = $(SIG_MED)
)
{
/etc/passwd        -> $(SEC_CONFIG) ;
/etc/shadow        -> $(SEC_CONFIG) ;
}
{
#/var/lock        -> $(SEC_CONFIG) ;
#/var/run        -> $(SEC_CONFIG) ; # daemon PIDs
/var/log        -> $(SEC_CONFIG) ;
}

# These files change the behavior of the root account
(
rulename = "Root config files",
severity = 100
)
{
/root                -> $(SEC_CRIT) ; # Catch all additions to /root
#/root/mail            -> $(SEC_CONFIG) ;
#/root/Mail            -> $(SEC_CONFIG) ;
/root/.xsession-errors        -> $(SEC_CONFIG) ;
#/root/.xauth            -> $(SEC_CONFIG) ;
#/root/.tcshrc            -> $(SEC_CONFIG) ;
#/root/.sawfish            -> $(SEC_CONFIG) ;
#/root/.pinerc            -> $(SEC_CONFIG) ;
#/root/.mc            -> $(SEC_CONFIG) ;
#/root/.gnome_private        -> $(SEC_CONFIG) ;
#/root/.gnome-desktop        -> $(SEC_CONFIG) ;
#/root/.gnome            -> $(SEC_CONFIG) ;
#/root/.esd_auth            -> $(SEC_CONFIG) ;
#    /root/.elm            -> $(SEC_CONFIG) ;
#/root/.cshrc                -> $(SEC_CONFIG) ;
#/root/.bashrc            -> $(SEC_CONFIG) ;
#/root/.bash_profile        -> $(SEC_CONFIG) ;
#    /root/.bash_logout        -> $(SEC_CONFIG) ;
#/root/.bash_history        -> $(SEC_CONFIG) ;
#/root/.amandahosts        -> $(SEC_CONFIG) ;
#/root/.addressbook.lu        -> $(SEC_CONFIG) ;
#/root/.addressbook        -> $(SEC_CONFIG) ;
#/root/.Xresources        -> $(SEC_CONFIG) ;
#/root/.Xauthority        -> $(SEC_CONFIG) -i ; # Changes Inode number on login
/root/.ICEauthority            -> $(SEC_CONFIG) ;
}

#
# Critical devices
#
(
rulename = "Devices & Kernel information",
severity = $(SIG_HI),
)
{
#/dev        -> $(Device) ;
#/proc        -> $(Device) ;
}

tripwire 报告

tripwire-check 命令检查 twpol.txt 文件并基于此文件生成 tripwire 报告如下。如果 twpol.txt 中有任何错误，tripwire 不会生成报告。

tripwire report

文本形式报告

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root@VMdebian:/home/labadmin# tripwire --check

Parsing policy file: /etc/tripwire/tw.pol

*** Processing Unix File System ***

Performing integrity check...

Wrote report file: /var/lib/tripwire/report/VMdebian-20151024-122322.twr

Open Source tripwire(R) 2.4.2.2 Integrity Check Report

Report generated by:         root

Report created on:           Sat Oct 24 12:23:22 2015

Database last updated on:     Never

Report Summary:

=========================================================

Host name:                   VMdebian

Host IP address:             127.0.1.1

Host ID:                     None

Policy file used:             /etc/tripwire/tw.pol

Configuration file used:     /etc/tripwire/tw.cfg

Database file used:           /var/lib/tripwire/VMdebian.twd

Command line used:           tripwire --check

=========================================================

Rule Summary:

=========================================================

-------------------------------------------------------------------------------

Section: Unix File System

-------------------------------------------------------------------------------

Rule Name                       Severity Level   Added   Removed Modified

---------                       --------------   -----   ------- --------

Other binaries                 66               0       0       0      

tripwire Binaries               100               0       0       0      

Other libraries                 66               0       0       0      

Root file-system executables   100               0       0       0      

tripwire Data Files             100               0       0       0      

System boot changes             100               0       0       0      

(/var/log)

Root file-system libraries     100               0       0       0      

(/lib)

Critical system boot files     100               0       0       0      

Other configuration files       66               0       0       0      

(/etc)

Boot Scripts                   100               0       0       0      

Security Control               66               0       0       0      

Root config files               100               0       0       0      

Invariant Directories           66               0       0       0      

Total objects scanned: 25943

Total violations found: 0

=========================Object Summary:================================

-------------------------------------------------------------------------------

# Section: Unix File System

-------------------------------------------------------------------------------

No violations.

===========================Error Report:=====================================

No Errors

-------------------------------------------------------------------------------

*** End of report ***

Open Source tripwire 2.4 Portions copyright 2000 tripwire, Inc. tripwire is a registered

trademark of tripwire, Inc. This software comes with ABSOLUTELY NO WARRANTY;

for details use --version. This is free software which may be redistributed

or modified only under certain conditions; see COPYING for details.

All rights reserved.

Integrity check complete.

总结

本篇中，我们学习安装配置开源入侵检测软件 tripwire。首先生成基础数据库并通过比较检测出任何改动（文件/文件夹）。然而，tripwire 并不是实时监测的 IDS。

via: http://linoxide.com/security/configure-tripwire-ids-debian/

作者：nido 译者：geekpi 校对：wxy

本文由 LCTT 原创编译，Linux中国 荣誉推出

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#Tripewire
如何在 Debian 中配置 Tripewire IDS
https://linuxcat.top/article-7185-1.html
作者
nido
发布于
2016年4月3日
许可协议
CC-BY-NC