162 lines
2.8 KiB
HTML
162 lines
2.8 KiB
HTML
<HTML
|
|
><HEAD
|
|
><TITLE
|
|
>Load Initialization Values Safely</TITLE
|
|
><META
|
|
NAME="GENERATOR"
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
|
|
REL="HOME"
|
|
TITLE="Secure Programming for Linux and Unix HOWTO"
|
|
HREF="index.html"><LINK
|
|
REL="UP"
|
|
TITLE="Structure Program Internals and Approach"
|
|
HREF="internals.html"><LINK
|
|
REL="PREVIOUS"
|
|
TITLE="Configure Safely and Use Safe Defaults"
|
|
HREF="safe-configure.html"><LINK
|
|
REL="NEXT"
|
|
TITLE="Fail Safe"
|
|
HREF="fail-safe.html"></HEAD
|
|
><BODY
|
|
CLASS="SECT1"
|
|
BGCOLOR="#FFFFFF"
|
|
TEXT="#000000"
|
|
LINK="#0000FF"
|
|
VLINK="#840084"
|
|
ALINK="#0000FF"
|
|
><DIV
|
|
CLASS="NAVHEADER"
|
|
><TABLE
|
|
SUMMARY="Header navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TH
|
|
COLSPAN="3"
|
|
ALIGN="center"
|
|
>Secure Programming for Linux and Unix HOWTO</TH
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="left"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="safe-configure.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="80%"
|
|
ALIGN="center"
|
|
VALIGN="bottom"
|
|
>Chapter 7. Structure Program Internals and Approach</TD
|
|
><TD
|
|
WIDTH="10%"
|
|
ALIGN="right"
|
|
VALIGN="bottom"
|
|
><A
|
|
HREF="fail-safe.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
></TABLE
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"></DIV
|
|
><DIV
|
|
CLASS="SECT1"
|
|
><H1
|
|
CLASS="SECT1"
|
|
><A
|
|
NAME="INIT-SAFE"
|
|
></A
|
|
>7.8. Load Initialization Values Safely</H1
|
|
><P
|
|
>Many programs read an initialization file to allow their defaults to be
|
|
configured.
|
|
You must ensure that an attacker can't change which initialization file
|
|
is used, nor create or modify that file.
|
|
Often you should <EM
|
|
>not</EM
|
|
> use the current directory
|
|
as a source of this information, since if the program is used as an
|
|
editor or browser, the user may be viewing the directory controlled
|
|
by someone else.
|
|
Instead, if the program is a typical user application, you should load
|
|
any user defaults from a hidden file or directory contained in the user's
|
|
home directory.
|
|
If the program is setuid/setgid, don't read any file controlled by the
|
|
user unless you carefully filter it as an untrusted (potentially
|
|
hostile) input.
|
|
Trusted configuration values should be loaded from somewhere else
|
|
entirely (typically from a file in /etc).</P
|
|
></DIV
|
|
><DIV
|
|
CLASS="NAVFOOTER"
|
|
><HR
|
|
ALIGN="LEFT"
|
|
WIDTH="100%"><TABLE
|
|
SUMMARY="Footer navigation table"
|
|
WIDTH="100%"
|
|
BORDER="0"
|
|
CELLPADDING="0"
|
|
CELLSPACING="0"
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="safe-configure.html"
|
|
ACCESSKEY="P"
|
|
>Prev</A
|
|
></TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="index.html"
|
|
ACCESSKEY="H"
|
|
>Home</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="fail-safe.html"
|
|
ACCESSKEY="N"
|
|
>Next</A
|
|
></TD
|
|
></TR
|
|
><TR
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="left"
|
|
VALIGN="top"
|
|
>Configure Safely and Use Safe Defaults</TD
|
|
><TD
|
|
WIDTH="34%"
|
|
ALIGN="center"
|
|
VALIGN="top"
|
|
><A
|
|
HREF="internals.html"
|
|
ACCESSKEY="U"
|
|
>Up</A
|
|
></TD
|
|
><TD
|
|
WIDTH="33%"
|
|
ALIGN="right"
|
|
VALIGN="top"
|
|
>Fail Safe</TD
|
|
></TR
|
|
></TABLE
|
|
></DIV
|
|
></BODY
|
|
></HTML
|
|
> |