/usr/share/doc/samhain/manual.html/security-design.html

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>The Samhain Host Integrity Monitoring System</TH
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><A
NAME="SECURITY-DESIGN"
></A
>Chapter 11. Security Design</H1
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="SECURITY-USAGE"
>11.1. Usage</A
></H1
><P
>It is recommended to:</P
><P
><P
></P
><UL
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>compile a static binary</I
></SPAN
> 
(not linked to shared libraries), using
the configure option <B
CLASS="COMMAND"
>--enable-static</B
> if possible 
(not possible
on Solaris &mdash; this is a Solaris problem, not 
a problem of <SPAN
CLASS="APPLICATION"
>samhain</SPAN
>)</P
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>strip the binary</I
></SPAN
> (on i386 Linux/FreeBSD, also 
use the provided <B
CLASS="COMMAND"
>sstrip</B
>
utility: <B
CLASS="COMMAND"
>strip samhain &amp;&amp; sstrip samhain</B
>). 
This will help
somewhat against intruders that try to run it under a debugger ...</P
><DIV
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>Note</B
></TH
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>&nbsp;</TD
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><P
><B
CLASS="COMMAND"
>make install</B
> will always strip the excutables. Trying
to strip again by hand may corrupt the executable.</P
></TD
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></DIV
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>use signed database/configuration files</I
></SPAN
> 
using the configure
option 
<B
CLASS="COMMAND"
>--with-gpg=PATH_TO_GPG</B
>, <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>and</I
></SPAN
> compile in
the fingerprint of the signing key (<B
CLASS="COMMAND"
> --with-fp=...</B
>)</P
></LI
><LI
><P
><SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>take a look at the stealth options</I
></SPAN
> - while 'security by
obscurity' <SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>only</I
></SPAN
> is a very bad idea, 
it certainly helps if an
intruder does not know what defenses you have in place</P
></LI
><LI
><P
>read the next chapter to understand how the 
<SPAN
CLASS="emphasis"
><I
CLASS="EMPHASIS"
>integrity of the samhain executable</I
></SPAN
> can be verified.</P
></LI
></UL
></P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="ATTACKBYSERVER"
>11.1.1. Client security in a client/server system</A
></H2
><P
>In a client/server Samhain system, if an intruder has obtained root 
privileges on the server he may modify configuration files that are
stored on the server and downloaded by the clients. Thus, if the client
executes shell commands given in the configuration file 
(via the shell expansion option, or by logging events to external commands 
specified in the configuration file), this may allow the intruder to take over
the clients as well.</P
><P
>As of version 2.8.5, there are two ways to protect against this scenario:</P
><P
>first, you can use the option <B
CLASS="COMMAND"
>--with-gpg=PATH</B
> to use
signed configuration (and baseline database) files. The signature is
checked on the client, after downloading the configuration file from the 
server. It is thus not possible to make the client perform any actions
if the configuration file is not signed correctly (note that in versions
before 2.8.5, the signature would be checked too late to prevent the attack).</P
><P
>second, you can just forego any execution of external programs by
compiling with the options 
<B
CLASS="COMMAND"
>--disable-shellexpand --disable-external-scripts</B
>.
No shell expansion will be performed on configuration file directives,
and no logging to external programs will be supported.</P
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samhain 3.1.0-5ubuntu1 / usr / share / doc / samhain / manual.html / security-design.html
