2005-03-13 22:11:45 +00:00
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<?xml version="1.0" encoding="ISO-8859-1"?>
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<!DOCTYPE article PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://docbook.org/xml/4.2/docbookx.dtd" []>
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2003-09-27 17:24:23 +00:00
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<article class="whitepaper" id="Encrypted-Root-Filesystem-HOWTO">
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<articleinfo>
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<title>Encrypted Root Filesystem HOWTO</title>
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<author>
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<firstname>Christophe</firstname>
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<surname>Devine</surname>
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</author>
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<abstract>
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<para>
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2003-12-02 01:23:23 +00:00
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This document explains how to make your personal data secure
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2003-09-27 17:24:23 +00:00
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by encrypting your Linux root filesystem using strong cryptography.
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</para>
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</abstract>
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<legalnotice>
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<para>
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This HOWTO is released under the GNU Free Documentation License
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Version 1.2.
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</para>
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</legalnotice>
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2016-03-29 17:58:09 +00:00
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<revhistory id="revhistory">
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2003-09-27 17:24:23 +00:00
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2005-03-13 22:11:45 +00:00
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<revision>
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<revnumber>v1.3</revnumber>
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<date>2005-03-13</date>
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<authorinitials>cd</authorinitials>
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<revremark>Updated the packages version.</revremark>
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</revision>
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2004-10-20 17:20:45 +00:00
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<revision>
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<revnumber>v1.2</revnumber>
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<date>2004-10-20</date>
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<authorinitials>cd</authorinitials>
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<revremark>Updated the packages version.</revremark>
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</revision>
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2003-12-02 01:23:23 +00:00
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<revision>
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<revnumber>v1.1</revnumber>
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<date>2003-12-01</date>
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<authorinitials>cd</authorinitials>
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<revremark>Added support for GRUB.</revremark>
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</revision>
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2003-09-27 17:24:23 +00:00
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<revision>
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<revnumber>v1.0</revnumber>
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<date>2003-09-24</date>
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<authorinitials>cd</authorinitials>
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<revremark>Initial release, reviewed by LDP.</revremark>
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</revision>
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<revision>
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<revnumber>v0.9</revnumber>
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<date>2003-09-11</date>
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<authorinitials>cd</authorinitials>
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<revremark>Updated and converted to DocBook XML.</revremark>
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</revision>
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</revhistory>
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</articleinfo>
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2003-12-02 01:23:23 +00:00
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<sect1 id="preparing-system">
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<title>Preparing the system</title>
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<sect2 id="partition-layout">
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<title>Setting up the partition layout</title>
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<para>
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Your hard disk (hda) should contain at least three partitions:
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<itemizedlist>
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<listitem><para>
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2004-10-20 17:20:45 +00:00
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hda1: this small unencrypted partition will ask for
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2003-09-27 17:24:23 +00:00
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a password in order to mount the encrypted root filesystem.
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2003-12-02 01:23:23 +00:00
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</para></listitem>
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<listitem><para>
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hda2: this partition will contain your encrypted root filesystem;
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make sure it is large enough.
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</para></listitem>
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<listitem><para>
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2003-09-27 17:24:23 +00:00
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hda3: this partition holds the current GNU/Linux system.
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2003-12-02 01:23:23 +00:00
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</para></listitem>
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</itemizedlist>
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</para><para>
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At this point, both hda1 and hda2 are unused. hda3 is where your
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Linux distribution is currently installed; /usr and /boot must
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<emphasis>not</emphasis> be separated from this partition.
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2004-10-20 17:20:45 +00:00
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</para><para>
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Here's an example of what your partition layout might look like:
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</para><para>
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<screen># fdisk -l /dev/hda
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Disk /dev/hda: 255 heads, 63 sectors, 2432 cylinders
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Units = cylinders of 16065 * 512 bytes
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Device Boot Start End Blocks Id System
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/dev/hda1 1 1 8001 83 Linux
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/dev/hda2 2 263 2104515 83 Linux
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/dev/hda3 264 525 2104515 83 Linux
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/dev/hda4 526 2047 12225465 83 Linux</screen>
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2005-03-13 22:11:45 +00:00
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</para>
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</sect2>
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<sect2 id="debian-packages">
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<title>Required packages</title>
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<para>
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If you use Debian, the following packages are mandatory:
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</para><para>
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<screen>apt-get install gcc make libncurses5-dev patch bzip2 wget</screen>
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</para><para>
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To make copy & paste easier, you should also install:
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</para><para>
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<screen>apt-get install lynx gpm</screen>
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</para>
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2003-12-02 01:23:23 +00:00
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</sect2>
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2003-09-27 17:24:23 +00:00
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2004-10-20 17:20:45 +00:00
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<sect2 id="install-kernel-2.4">
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2005-03-13 22:11:45 +00:00
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<title>Installing Linux-2.4.29</title>
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2003-09-27 17:24:23 +00:00
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<para>
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2004-10-20 17:20:45 +00:00
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There are two main projects which add loopback encryption support in the
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kernel: cryptoloop and loop-AES. This howto is based on loop-AES, since it
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features an extremely fast and highly optimized implementation of Rijndael
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2003-09-27 17:24:23 +00:00
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in assembly language, and therefore provides maximum performance if
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2004-10-20 17:20:45 +00:00
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you have an IA-32 (x86) CPU. Besides, there are some
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2005-03-13 22:11:45 +00:00
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<ulink url="http://groups.google.com/groups?selm=1emrG-1Ck-25%40gated-at.bofh.it">security concerns</ulink>
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2004-10-20 17:20:45 +00:00
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about cryptoloop.
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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First of all, download and unpack the loop-AES package:
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2003-09-27 17:24:23 +00:00
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</para><para>
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2005-03-13 22:11:45 +00:00
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<screen>cd /usr/src
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wget http://loop-aes.sourceforge.net/loop-AES/loop-AES-v3.0b.tar.bz2
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tar -xvjf loop-AES-v3.0b.tar.bz2</screen>
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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Then you must download and patch the kernel source:
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2003-09-27 17:24:23 +00:00
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</para><para>
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2005-03-13 22:11:45 +00:00
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<screen>wget http://ftp.kernel.org/pub/linux/kernel/v2.4/linux-2.4.29.tar.bz2
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tar -xvjf linux-2.4.29.tar.bz2
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cd linux-2.4.29
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rm include/linux/loop.h drivers/block/loop.c
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patch -Np1 -i ../loop-AES-v3.0b/kernel-2.4.28.diff</screen>
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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Setup the keyboard map:
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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<screen>dumpkeys | loadkeys -m - > drivers/char/defkeymap.c</screen>
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2003-09-27 17:24:23 +00:00
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</para><para>
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Next, configure your kernel; make sure the following options are set:
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</para><para>
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2003-12-02 01:23:23 +00:00
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<screen>make menuconfig
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Block devices --->
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2003-09-27 17:24:23 +00:00
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<*> Loopback device support
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[*] AES encrypted loop device support (NEW)
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<*> RAM disk support
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(4096) Default RAM disk size (NEW)
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2003-12-02 01:23:23 +00:00
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[*] Initial RAM disk (initrd) support
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File systems --->
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<*> Ext3 journalling file system support
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<*> Second extended fs support
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(important note: do not enable /dev file system support)</screen>
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</para><para>
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2003-12-02 01:23:23 +00:00
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Compile the kernel and install it:
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</para><para>
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<screen>make dep bzImage
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make modules modules_install
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cp arch/i386/boot/bzImage /boot/vmlinuz</screen>
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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If grub is your bootloader, update /boot/grub/menu.lst
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or /boot/grub/grub.conf:
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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<screen>cat > /boot/grub/menu.lst << EOF
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default 0
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timeout 10
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color green/black light-green/black
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title Linux
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root (hd0,2)
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kernel /boot/vmlinuz ro root=/dev/hda3
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2003-12-02 01:23:23 +00:00
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EOF</screen>
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</para><para>
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Otherwise, update /etc/lilo.conf and run lilo:
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</para><para>
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<screen>cat > /etc/lilo.conf << EOF
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lba32
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boot=/dev/hda
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prompt
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timeout=60
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image=/boot/vmlinuz
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label=Linux
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read-only
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root=/dev/hda3
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EOF
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lilo</screen>
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</para><para>
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You may now restart the system.
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2003-09-27 17:24:23 +00:00
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</para>
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</sect2>
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2003-12-02 01:23:23 +00:00
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2004-10-20 17:20:45 +00:00
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<sect2 id="install-kernel-2.6">
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2005-03-13 22:11:45 +00:00
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<title>Installing Linux-2.6.10</title>
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2004-10-20 17:20:45 +00:00
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<para>
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Proceed as described in the previous section, using loop-aes'
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2005-03-13 22:11:45 +00:00
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<emphasis>kernel-2.6.10.diff</emphasis> patch instead, and make
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sure cryptoloop support is <emphasis>not</emphasis> activated.
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Note that modules support require that you have the module-init-tools
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package installed.
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</para>
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</sect2>
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2003-09-27 17:24:23 +00:00
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<sect2 id="install-util-linux">
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2005-03-13 22:11:45 +00:00
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<title>Installing util-linux-2.12p</title>
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2003-12-02 01:23:23 +00:00
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<para>
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2003-09-27 17:24:23 +00:00
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The losetup program, which is part of the util-linux package, must be
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patched and recompiled in order to add strong cryptography support.
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2003-12-02 01:23:23 +00:00
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Download, unpack and patch util-linux:
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</para><para>
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2005-03-13 22:11:45 +00:00
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<screen>cd /usr/src
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wget http://ftp.kernel.org/pub/linux/utils/util-linux/util-linux-2.12p.tar.bz2
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tar -xvjf util-linux-2.12p.tar.bz2
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cd util-linux-2.12p
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patch -Np1 -i ../loop-AES-v3.0b/util-linux-2.12p.diff</screen>
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2003-12-02 01:23:23 +00:00
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</para><para>
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2003-09-27 17:24:23 +00:00
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To use passwords that are less than 20 characters, enter:
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2003-12-02 01:23:23 +00:00
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</para><para>
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<screen>CFLAGS="-O2 -DLOOP_PASSWORD_MIN_LENGTH=8"; export CFLAGS</screen>
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</para><para>
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2005-03-13 22:11:45 +00:00
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Security is certainly your major concern. For this reason, please do not
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enable passwords shorter than 20 characters. Data privacy is not free,
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2004-10-20 17:20:45 +00:00
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one has to 'pay' in form of long passwords.
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2003-12-02 01:23:23 +00:00
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</para><para>
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2003-09-27 17:24:23 +00:00
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Compile losetup and install it as root:
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2003-12-02 01:23:23 +00:00
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</para><para>
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<screen>./configure && make lib mount
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2004-10-20 17:20:45 +00:00
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mv -f /sbin/losetup /sbin/losetup~
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rm -f /usr/share/man/man8/losetup.8*
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cd mount
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gzip losetup.8
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cp losetup /sbin
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2005-03-13 22:11:45 +00:00
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cp losetup.8.gz /usr/share/man/man8/
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chattr +i /sbin/losetup</screen>
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2003-12-02 01:23:23 +00:00
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</para>
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2003-09-27 17:24:23 +00:00
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</sect2>
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</sect1>
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<sect1 id="encrypt-root-filesystem">
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<title>Creating the encrypted root filesystem</title>
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<para>
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Fill the target partition with random data:
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</para><para>
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2003-12-02 01:23:23 +00:00
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<screen>shred -n 1 -v /dev/hda2</screen>
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2003-09-27 17:24:23 +00:00
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</para><para>
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Setup the encrypted loopback device:
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</para><para>
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2004-10-20 17:20:45 +00:00
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<screen>losetup -e aes256 -S xxxxxx /dev/loop0 /dev/hda2</screen>
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2003-09-27 17:24:23 +00:00
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</para><para>
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2003-12-02 01:23:23 +00:00
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To prevent optimized dictionary attacks, it is recommended to add
|
2004-10-20 17:20:45 +00:00
|
|
|
|
the -S xxxxxx option, where "xxxxxx" is your randomly chosen
|
2005-03-13 22:11:45 +00:00
|
|
|
|
seed (for example, you might choose "gPk4lA"). Write down your seed on
|
|
|
|
|
a piece of paper so that you don't loose it afterwards. Also, in order
|
|
|
|
|
to avoid boot-time problems with the keyboard map, do not use non-ASCII
|
2004-10-20 17:20:45 +00:00
|
|
|
|
characters (accents, etc.) in your password. The
|
|
|
|
|
<ulink url="http://www.diceware.com/">Diceware</ulink> site offers
|
|
|
|
|
a simple way to create strong, yet easy to remember, passphrases.
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
Now create the ext3 filesystem:
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<screen>mke2fs -j /dev/loop0</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
Check that the password you entered is correct:
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<screen>losetup -d /dev/loop0
|
2004-10-20 17:20:45 +00:00
|
|
|
|
losetup -e aes256 -S xxxxxx /dev/loop0 /dev/hda2</screen>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
<screen>mkdir /mnt/efs
|
|
|
|
|
mount /dev/loop0 /mnt/efs</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
You can compare the encrypted and unencrypted data:
|
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<screen>xxd /dev/hda2 | less
|
|
|
|
|
xxd /dev/loop0 | less</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
It's time to install your encrypted Linux system. If you use a GNU/Linux
|
|
|
|
|
distribution (such as Debian, Slackware, Gentoo, Mandrake, RedHat/Fedora,
|
|
|
|
|
SuSE, etc.), run the following command:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>cp -avx / /mnt/efs</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
If you use the Linux From Scratch book, proceed as described in
|
|
|
|
|
the manual, with the modifications below:
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
<para>Chapter 6 - Installing util-linux:</para>
|
|
|
|
|
<para>Apply the loop-AES patch after unpacking the sources.</para>
|
|
|
|
|
</listitem><listitem>
|
|
|
|
|
<para>Chapter 8 - Making the LFS system bootable:</para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
<para>Refer to the next section (Setting up the boot device).</para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
</listitem>
|
|
|
|
|
</itemizedlist>
|
|
|
|
|
</para>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</sect1>
|
|
|
|
|
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<sect1 id="setup-boot-device">
|
2003-09-27 17:24:23 +00:00
|
|
|
|
<title>Setting up the boot device</title>
|
|
|
|
|
<sect2 id="initial-ramdisk">
|
|
|
|
|
<title>Creating the ramdisk</title>
|
|
|
|
|
<para>
|
|
|
|
|
To begin with, chroot inside the encrypted partition and create
|
|
|
|
|
the boot device mount point:
|
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<screen>chroot /mnt/efs
|
2003-09-27 17:24:23 +00:00
|
|
|
|
mkdir /loader</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
Then, create the initial ramdisk (initrd), which will be needed
|
|
|
|
|
afterwards:
|
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<screen>cd
|
|
|
|
|
dd if=/dev/zero of=initrd bs=1k count=4096
|
2003-09-27 17:24:23 +00:00
|
|
|
|
mke2fs -F initrd
|
|
|
|
|
mkdir ramdisk
|
|
|
|
|
mount -o loop initrd ramdisk</screen>
|
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
If you're using grsecurity, you may get a "Permission denied" error
|
|
|
|
|
message; in this case you'll have to run the mount command outside chroot.
|
|
|
|
|
</para><para>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
Create the filesystem hierarchy and copy the required files in it:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>mkdir ramdisk/{bin,dev,lib,mnt,sbin}
|
2004-10-20 17:20:45 +00:00
|
|
|
|
cp /bin/{bash,mount} ramdisk/bin/
|
2003-12-02 01:23:23 +00:00
|
|
|
|
ln -s bash ramdisk/bin/sh
|
|
|
|
|
mknod -m 600 ramdisk/dev/console c 5 1
|
|
|
|
|
mknod -m 600 ramdisk/dev/hda2 b 3 2
|
|
|
|
|
mknod -m 600 ramdisk/dev/loop0 b 7 0
|
|
|
|
|
cp /lib/{ld-linux.so.2,libc.so.6,libdl.so.2} ramdisk/lib/
|
|
|
|
|
cp /lib/{libncurses.so.5,libtermcap.so.2} ramdisk/lib/
|
2003-09-27 17:24:23 +00:00
|
|
|
|
cp /sbin/{losetup,pivot_root} ramdisk/sbin/</screen>
|
|
|
|
|
</para><para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
It's ok if you see a message like "/lib/libncurses.so.5: No such file
|
|
|
|
|
or directory", or "/lib/libtermcap.so.2: No such file or directory";
|
|
|
|
|
bash only requires one of these two libraries. You can check which one
|
2004-10-20 17:20:45 +00:00
|
|
|
|
is actually required with:
|
2003-12-02 01:23:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
<screen>ldd /bin/bash</screen>
|
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
Compile the sleep program, which will prevent the password prompt
|
|
|
|
|
being flooded by kernel messages (such as usb devices being registered).
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>cat > sleep.c << "EOF"
|
|
|
|
|
#include <unistd.h>
|
|
|
|
|
#include <stdlib.h>
|
|
|
|
|
|
|
|
|
|
int main( int argc, char *argv[] )
|
|
|
|
|
{
|
|
|
|
|
if( argc == 2 )
|
|
|
|
|
sleep( atoi( argv[1] ) );
|
|
|
|
|
|
|
|
|
|
return( 0 );
|
|
|
|
|
}
|
|
|
|
|
EOF
|
|
|
|
|
|
|
|
|
|
gcc -s sleep.c -o ramdisk/bin/sleep
|
|
|
|
|
rm sleep.c</screen>
|
|
|
|
|
</para><para>
|
2005-03-13 22:11:45 +00:00
|
|
|
|
Create the init script:
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
<screen>cat > ramdisk/sbin/init << "EOF"
|
|
|
|
|
#!/bin/sh
|
|
|
|
|
|
2004-10-20 17:20:45 +00:00
|
|
|
|
/bin/sleep 3
|
2005-03-13 22:11:45 +00:00
|
|
|
|
|
|
|
|
|
echo -n "Enter seed value: "
|
|
|
|
|
read SEED
|
|
|
|
|
|
|
|
|
|
/sbin/losetup -e aes256 -S $SEED /dev/loop0 /dev/hda2
|
2004-10-20 17:20:45 +00:00
|
|
|
|
/bin/mount -r -n -t ext3 /dev/loop0 /mnt
|
2003-09-27 17:24:23 +00:00
|
|
|
|
|
|
|
|
|
while [ $? -ne 0 ]
|
|
|
|
|
do
|
|
|
|
|
/sbin/losetup -d /dev/loop0
|
2005-03-13 22:11:45 +00:00
|
|
|
|
/sbin/losetup -e aes256 -S $SEED /dev/loop0 /dev/hda2
|
2004-10-20 17:20:45 +00:00
|
|
|
|
/bin/mount -r -n -t ext3 /dev/loop0 /mnt
|
2003-09-27 17:24:23 +00:00
|
|
|
|
done
|
|
|
|
|
|
|
|
|
|
cd /mnt
|
|
|
|
|
/sbin/pivot_root . loader
|
|
|
|
|
exec /usr/sbin/chroot . /sbin/init
|
|
|
|
|
EOF
|
|
|
|
|
|
|
|
|
|
chmod 755 ramdisk/sbin/init</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
Umount the loopback device and compress the initrd:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>umount -d ramdisk
|
|
|
|
|
rmdir ramdisk
|
2003-12-02 01:23:23 +00:00
|
|
|
|
gzip initrd
|
|
|
|
|
mv initrd.gz /boot/</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para>
|
|
|
|
|
</sect2>
|
|
|
|
|
<sect2 id="bootable-cd">
|
2004-10-20 17:20:45 +00:00
|
|
|
|
<title>Booting from a CD-ROM</title>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
<para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
I strongly advise you to start your system with a read-only
|
|
|
|
|
media, such as a bootable CD-ROM.
|
|
|
|
|
</para><para>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
Download and unpack syslinux:
|
|
|
|
|
</para><para>
|
2005-03-13 22:11:45 +00:00
|
|
|
|
<screen>wget http://ftp.kernel.org/pub/linux/utils/boot/syslinux/syslinux-3.07.tar.bz2
|
|
|
|
|
tar -xvjf syslinux-3.07.tar.bz2</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
Configure isolinux:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>mkdir bootcd
|
2005-03-13 22:11:45 +00:00
|
|
|
|
cp /boot/{vmlinuz,initrd.gz} syslinux-3.07/isolinux.bin bootcd
|
2004-10-20 17:20:45 +00:00
|
|
|
|
echo "DEFAULT /vmlinuz initrd=initrd.gz ro root=/dev/ram0" \
|
2003-09-27 17:24:23 +00:00
|
|
|
|
> bootcd/isolinux.cfg</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
Create and burn the bootable cd-rom iso image:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>mkisofs -o bootcd.iso -b isolinux.bin -c boot.cat \
|
|
|
|
|
-no-emul-boot -boot-load-size 4 -boot-info-table \
|
|
|
|
|
-J -hide-rr-moved -R bootcd/
|
|
|
|
|
|
2003-12-02 01:23:23 +00:00
|
|
|
|
cdrecord -dev 0,0,0 -speed 4 -v bootcd.iso
|
|
|
|
|
|
|
|
|
|
rm -rf bootcd{,.iso}</screen>
|
|
|
|
|
</para>
|
|
|
|
|
</sect2>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<sect2 id="boot-partition">
|
2004-10-20 17:20:45 +00:00
|
|
|
|
<title>Booting from a HD partition</title>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
The boot partition can come in handy if you happen to lose your bootable
|
|
|
|
|
CD. <emphasis>Remember that hda1 is a writable media and is thus insecure;
|
|
|
|
|
use it only in case of emergency!</emphasis>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
Create and mount the ext2 filesystem:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>dd if=/dev/zero of=/dev/hda1 bs=8192
|
|
|
|
|
mke2fs /dev/hda1
|
|
|
|
|
mount /dev/hda1 /loader</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
Copy the kernel and the initial ramdisk:
|
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
<screen>cp /boot/{vmlinuz,initrd.gz} /loader</screen>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
If you use grub:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>mkdir /loader/boot
|
|
|
|
|
cp -av /boot/grub /loader/boot/
|
|
|
|
|
cat > /loader/boot/grub/menu.lst << EOF
|
|
|
|
|
default 0
|
|
|
|
|
timeout 10
|
|
|
|
|
color green/black light-green/black
|
|
|
|
|
title Linux
|
|
|
|
|
root (hd0,0)
|
2004-10-20 17:20:45 +00:00
|
|
|
|
kernel /vmlinuz ro root=/dev/ram0
|
2003-12-02 01:23:23 +00:00
|
|
|
|
initrd /initrd.gz
|
|
|
|
|
EOF
|
|
|
|
|
grub-install --root-directory=/loader /dev/hda
|
|
|
|
|
umount /loader</screen>
|
|
|
|
|
</para><para>
|
|
|
|
|
If you use lilo:
|
|
|
|
|
</para><para>
|
|
|
|
|
<screen>mkdir /loader/{boot,dev,etc}
|
|
|
|
|
cp /boot/boot.b /loader/boot/
|
|
|
|
|
mknod -m 600 /loader/dev/hda b 3 0
|
|
|
|
|
mknod -m 600 /loader/dev/hda1 b 3 1
|
2005-03-13 22:11:45 +00:00
|
|
|
|
mknod -m 600 /loader/dev/hda2 b 3 2
|
|
|
|
|
mknod -m 600 /loader/dev/hda3 b 3 3
|
|
|
|
|
mknod -m 600 /loader/dev/hda4 b 3 4
|
2003-12-02 01:23:23 +00:00
|
|
|
|
mknod -m 600 /loader/dev/ram0 b 1 0
|
|
|
|
|
cat > /loader/etc/lilo.conf << EOF
|
|
|
|
|
lba32
|
|
|
|
|
boot=/dev/hda
|
|
|
|
|
prompt
|
2005-03-13 22:11:45 +00:00
|
|
|
|
timeout=60
|
2003-12-02 01:23:23 +00:00
|
|
|
|
image=/vmlinuz
|
|
|
|
|
label=Linux
|
|
|
|
|
initrd=/initrd.gz
|
|
|
|
|
read-only
|
|
|
|
|
root=/dev/ram0
|
|
|
|
|
EOF
|
|
|
|
|
lilo -r /loader
|
|
|
|
|
umount /loader</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para>
|
|
|
|
|
</sect2>
|
|
|
|
|
</sect1>
|
|
|
|
|
|
2003-12-02 01:23:23 +00:00
|
|
|
|
<sect1 id="final-steps">
|
|
|
|
|
<title>Final steps</title>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
<para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
Still inside chroot, modify /etc/fstab so that it contains:
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
<screen>/dev/loop0 / ext3 defaults 0 1</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2005-03-13 22:11:45 +00:00
|
|
|
|
Delete /etc/mtab and exit from chroot. Finally, run "umount -d /mnt/efs"
|
2004-10-20 17:20:45 +00:00
|
|
|
|
and reboot. If something goes wrong, you can still boot your unencrypted
|
|
|
|
|
partition by entering "Linux root=/dev/hda3" at the LILO: prompt.
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
If everything went well, you can now re-partition your disk and encrypt
|
|
|
|
|
hda3 as well as hda4. In the following scripts, we assume that hda3 will
|
|
|
|
|
hold the swap device and hda4 will contain /home; you should initialize
|
|
|
|
|
both partitions first:
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
<screen>shred -n 1 -v /dev/hda3
|
|
|
|
|
shred -n 1 -v /dev/hda4
|
|
|
|
|
losetup -e aes256 -S xxxxxx /dev/loop1 /dev/hda3
|
|
|
|
|
losetup -e aes256 -S xxxxxx /dev/loop2 /dev/hda4
|
|
|
|
|
mkswap /dev/loop1
|
|
|
|
|
mke2fs -j /dev/loop2</screen>
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para><para>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
Then create a script in the system startup directory and update fstab:
|
2003-09-27 17:24:23 +00:00
|
|
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</para><para>
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2004-10-20 17:20:45 +00:00
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<screen>cat > /etc/init.d/loop << "EOF"
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#!/bin/sh
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if [ "`/usr/bin/md5sum /dev/hda1`" != \
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"5671cebdb3bed87c3b3c345f0101d016 /dev/hda1" ]
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|
then
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echo -n "WARNING! hda1 integrity verification FAILED - press enter."
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|
read
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|
fi
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echo "1st password chosen above" | \
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|
|
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|
/sbin/losetup -p 0 -e aes256 -S xxxxxx /dev/loop1 /dev/hda3
|
2003-12-02 01:23:23 +00:00
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|
2004-10-20 17:20:45 +00:00
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|
|
echo "2nd password chosen above" | \
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|
|
/sbin/losetup -p 0 -e aes256 -S xxxxxx /dev/loop2 /dev/hda4
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|
|
/sbin/swapon /dev/loop1
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|
|
for i in `seq 0 63`
|
|
|
|
|
do
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|
|
|
|
echo -n -e "\33[10;10]\33[11;10]" > /dev/tty$i
|
|
|
|
|
done
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|
|
EOF
|
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|
|
chmod 700 /etc/init.d/loop
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|
|
|
ln -s ../init.d/loop /etc/rcS.d/S00loop
|
|
|
|
|
vi /etc/fstab
|
|
|
|
|
...
|
|
|
|
|
/dev/loop2 /home ext3 defaults 0 2</screen>
|
2003-09-27 17:24:23 +00:00
|
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|
|
</para>
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|
|
</sect1>
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|
|
<sect1 id="about">
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|
|
|
|
<title>About this HOWTO</title>
|
|
|
|
|
<para>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
The Encrypted Root Filesystem HOWTO was first written in november 2002 for the
|
|
|
|
|
<ulink url="http://www.linuxfromscratch.org/lfs/news.html">Linux From Scratch</ulink>
|
2005-03-13 22:11:45 +00:00
|
|
|
|
project. I'd like to thank the many people who have since contributed to
|
|
|
|
|
this document (in reverse chronological order): Micha Borrmann,
|
|
|
|
|
Dennis Lemckert, Oleg Vyushin, Ellen Bokhorst, Daczi L<>szl<7A>, Gaetano Zappulla,
|
|
|
|
|
Guillaume Lehmann, Claude Thomassin, Jean-Philippe Gu<47>rard, Luc Vo Van,
|
|
|
|
|
Jacobus Brink, Ernesto P<>rez Est<73>vez, Matthew Ploessel, Mike Lorek,
|
|
|
|
|
Lars Bungum, Michael Shields, Julien Perrot, Grant Stephenson, Cary W. Gilmer,
|
|
|
|
|
James Howells, Pedro Baez, Josh Purinton, Jari Ruusu and Zibeli Aton.
|
2004-10-20 17:20:45 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
This HOWTO has been translated in various languages:
|
|
|
|
|
<itemizedlist>
|
|
|
|
|
<listitem><para><ulink url="http://www.traduc.org/docs/HOWTO/lecture/Encrypted-Root-Filesystem-HOWTO.html">French</ulink></para></listitem>
|
|
|
|
|
<listitem><para><ulink url="http://www.linux.it/~gaetano/erfs/">Italian</ulink></para></listitem>
|
|
|
|
|
<listitem><para><ulink url="http://tldp.fsf.hu/HOWTO/Encrypted-Root-Filesystem-HOWTO-hu/">Hungarian</ulink></para></listitem>
|
2005-03-13 22:11:45 +00:00
|
|
|
|
<listitem><para><ulink url="http://doc.nl.linux.org/HOWTO/Encrypted-Root-Filesystem-HOWTO-NL/article.html">Dutch</ulink></para></listitem>
|
2004-10-20 17:20:45 +00:00
|
|
|
|
</itemizedlist>
|
2003-12-02 01:23:23 +00:00
|
|
|
|
</para><para>
|
|
|
|
|
Please send any comment to
|
|
|
|
|
<ulink url="http://www.cr0.net:8040/about/">Christophe Devine</ulink>.
|
2003-09-27 17:24:23 +00:00
|
|
|
|
</para>
|
|
|
|
|
</sect1>
|
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|
</article>
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|