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Posted to cvs@httpd.apache.org by Randy Terbush <ra...@hyperreal.com> on 1997/06/05 22:07:22 UTC

cvs commit: apache/htdocs/manual suexec.html

randy       97/06/05 13:07:21

  Modified:    htdocs/manual  suexec.html
  Log:
  Update suexec docs.
  Reviewed by: Ken Coar, Randy Terbush
  Submitted by: Jason Dour
  
  Revision  Changes    Path
  1.11      +447 -132  apache/htdocs/manual/suexec.html
  
  Index: suexec.html
  ===================================================================
  RCS file: /export/home/cvs/apache/htdocs/manual/suexec.html,v
  retrieving revision 1.10
  retrieving revision 1.11
  diff -C3 -r1.10 -r1.11
  *** suexec.html	1997/06/04 11:07:51	1.10
  --- suexec.html	1997/06/05 20:07:19	1.11
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    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
  ! <html><head>
  ! <title>Apache SetUserID Support</title>
  ! </head>
  ! 
    <!-- Background white, links blue (unvisited), navy (visited), red (active) -->
    <BODY
     BGCOLOR="#FFFFFF"
  --- 1,8 ----
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
  ! <HTML>
  ! <HEAD>
  ! <TITLE>Apache suEXEC Support</TITLE>
  ! </HEAD>
    <!-- Background white, links blue (unvisited), navy (visited), red (active) -->
    <BODY
     BGCOLOR="#FFFFFF"
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    >
    <!--#include virtual="header.html" -->
  - <h1 ALIGN="CENTER">Apache suEXEC Support</h1>
    
  ! <hr>
    
  ! <h3>What is suEXEC?</h3>
  ! The <STRONG>suEXEC</STRONG> feature, introduced in Apache 1.2 provides
  ! the ability to run <STRONG>CGI</STRONG> programs under user IDs
  ! different from the user ID of the calling web-server. Used properly,
  ! this feature can reduce considerably the insecurity of allowing users to
  ! run CGI programs. At the same time, improperly configured, this facility
  ! can crash your computer, burn your house down and steal all the money
  ! from your retirement fund. <STRONG>:-)</STRONG> If you aren't familiar
  ! with managing setuid root programs and the security issues they
  ! present, we highly recommend that you not consider using this feature.<p>
  ! 
  ! <hr>
  ! 
  ! <h3>Enabling suEXEC Support</h3>
  ! Having said all that, enabling this feature is purposefully difficult with
  ! the intent that it will only be installed by users determined to use it and
  ! is not part of the normal install/compile process.<p>
  ! 
  ! <h3>Configuring the suEXEC wrapper</h3>
  ! From the top-level of the Apache source tree,
  ! type:&nbsp;&nbsp;<STRONG><code>cd support [ENTER]</code></STRONG><p>
    Edit the <code>suexec.h</code> file and change the following macros to
  ! match your local Apache installation.<p>
    <EM>From support/suexec.h</EM>
  ! <pre>
  ! /*
  !  * HTTPD_USER -- Define as the username under which Apache normally
  !  *               runs.  This is the only user allowed to execute
  !  *               this program.
  !  */
  ! #define HTTPD_USER "www"
  ! 
  ! /*
  !  * LOG_EXEC -- Define this as a filename if you want all suEXEC
  !  *             transactions and errors logged for auditing and
  !  *             debugging purposes.
  !  */
  ! #define LOG_EXEC "/usr/local/etc/httpd/logs/cgi.log"
  ! 
  ! /*
  !  * DOC_ROOT -- Define as the DocumentRoot set for Apache.  This
  !  *             will be the only hierarchy (aside from UserDirs)
  !  *             that can be used for suEXEC behavior.
  !  */
  ! #define DOC_ROOT "/usr/local/etc/httpd/htdocs"
  ! 
  ! /*
  !  * SAFE_PATH -- Define a safe PATH environment to pass to CGI executables.
  !  *
  !  */
  ! #define SAFE_PATH "/usr/local/bin:/usr/bin:/bin"
  ! </pre>
  ! 
  ! <h3>Compiling the suEXEC wrapper</h3>
  ! At the shell command prompt, type:&nbsp;&nbsp;<STRONG><code>cc suexec.c
  ! -o suexec [ENTER]</code></STRONG>.<p>
    This should create the <STRONG><em>suexec</em></STRONG> wrapper executable.
    
  ! <h3>Compiling Apache for suEXEC support</h3>
    By default, Apache is compiled to look for the suEXEC wrapper in the following
  ! location.<p>
    <EM>From src/httpd.h</EM>
  ! <pre>
  ! /* The path to the suEXEC wrapper */
  ! #ifndef SUEXEC_BIN
  ! #define SUEXEC_BIN "/usr/local/etc/httpd/sbin/suexec"
  ! #endif
  ! </pre>
  ! <p>
    If your installation requires location of the wrapper program in a different
    directory, edit src/httpd.h and recompile your Apache server.
  ! See <a href="install.html">Compiling and Installing Apache</a> for more
  ! info on this process.<p>
    
  ! <h3>Installing the suEXEC wrapper</h3>
    Copy the <STRONG><em>suexec</em></STRONG> executable created in the
  ! exercise above to the defined location for <STRONG>SUEXEC_BIN</STRONG>.<p>
  ! In order for the wrapper to set the user ID for execution requests it
  ! must me installed as owner <STRONG><em>root</em></STRONG> and must have
  ! the setuserid execution bit set for file modes.
  ! If you are not running a <STRONG><em>root</em></STRONG> user shell, do
  ! so now and execute the following commands.<p>
  ! 
  ! <STRONG><code>chown root /usr/local/etc/httpd/sbin/suexec [ENTER]</code></STRONG><p>
  ! <STRONG><code>chmod 4711 /usr/local/etc/httpd/sbin/suexec [ENTER]</code></STRONG><p>
  ! 
  ! <EM>Change the path to the suEXEC wrapper to match your system
  ! installation.</EM>
  ! 
  ! <hr>
  ! 
  ! <h3><a name="model">Security Model of suEXEC</a></h3>
  ! The <STRONG>suEXEC</STRONG> wrapper supplied with Apache performs the
  ! following security checks before it will execute any program passed to
  ! it for execution.
  ! <ol>
  ! <li>User executing the wrapper <STRONG>must be a valid user on this
  !  system</STRONG>.
  ! <li>User executing the wrapper <STRONG>must be the compiled in
  !  HTTPD_USER</STRONG>.
  ! <li>The command that the request wishes to execute <STRONG>must not
  !  contain a leading / or ../, or the string &quot;/../&quot; anywhere</STRONG>.
  ! <li>The command being executed <STRONG>must reside under the compiled in
  !  DOC_ROOT</STRONG>.
  ! <li>The current working directory <STRONG>must be a directory</STRONG>.
  ! <li>The current working directory <STRONG>must not be writable by
  !  <em>group</em> or <em>other</em></STRONG>.
  ! <li>The command being executed <STRONG>cannot be a symbolic link</STRONG>.
  ! <li>The command being executed <STRONG>cannot be writable by
  !  <em>group</em> or <em>other</em></STRONG>.
  ! <li>The command being executed <STRONG>cannot be a <em>setuid</em> or
  !  <em>setgid</em> program</STRONG>.
  ! <li>The target UID and GID <STRONG>must be a valid user and group on
  !  this system</STRONG>.
  ! <li>The target UID and GID to execute as, <STRONG>must match the UID and
  !  GID of the directory</STRONG>.
  ! <li>The target execution UID and GID <STRONG>must not be the privileged
  !  ID 0</STRONG>.
  ! </ol>
  ! If any of these issues are too restrictive, or do not seem restrictive
  ! enough, you are welcome to install your own version of the wrapper.
  ! We've given you the rope, now go have fun with it. <STRONG>:-)</STRONG>
    
  ! <hr>
    
  ! <h3>Using suEXEC</h3>
    After properly installing the <STRONG>suexec</STRONG> wrapper
  ! executable, you must kill and restart the Apache server. A simple
  ! <code><STRONG>kill -1 `cat httpd.pid`</STRONG></code> will not be enough.
    Upon startup of the web-server, if Apache finds a properly configured
    <STRONG>suexec</STRONG> wrapper, it will print the following message to
  ! the console:<p>
    
  ! <code>Configuring Apache for use with suexec wrapper.</code><p>
    
    If you don't see this message at server startup, the server is most
    likely not finding the wrapper program where it expects it, or the
  ! executable is not installed <STRONG><em>setuid root</em></STRONG>. Check
  ! your installation and try again.<p>
    
    One way to use <STRONG>suEXEC</STRONG> is through the
    <a href="mod/core.html#user"><STRONG>User</STRONG></a> and
    <a href="mod/core.html#group"><STRONG>Group</STRONG></a> directives in
  --- 12,423 ----
     ALINK="#FF0000"
    >
    <!--#include virtual="header.html" -->
    
  ! <H1 ALIGN="CENTER">Apache suEXEC Support</H1>
  ! 
  ! <P ALIGN="LEFT">
  ! <OL>
  ! 	<LH><BIG><STRONG>CONTENTS</STRONG></BIG></LH>
  ! 	<LI><A HREF="#what">What is suEXEC?</A></LI>
  ! 	<LI><A HREF="#before">Before we begin.</A></LI>
  ! 	<LI><A HREF="#model">suEXEC Security Model.</A></LI>
  ! 	<LI><A HREF="#install">Configuring & Installing suEXEC</A></LI>
  ! 	<LI><A HREF="#enable">Enabling & Disabling suEXEC</A></LI>
  ! 	<LI><A HREF="#debug">Debugging suEXEC</A></LI>
  ! 	<LI><A HREF="#jabberwock">Beware the Jabberwock: Warnings & Examples</A></LI>
  ! </OL>
  ! </P>
  ! 
  ! <H3><A NAME="what">What is suEXEC?</A></H3>
  ! <P ALIGN="LEFT">
  ! The <STRONG>suEXEC</STRONG> feature -- introduced in Apache 1.2 -- provides
  ! Apache users the ability to run <STRONG>CGI</STRONG> and <STRONG>SSI</STRONG>
  ! programs under user IDs different from the user ID of the calling web-server.
  ! Normally, when a CGI or SSI program executes, it runs as the same user who is
  ! running the web server.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! Used properly, this feature can reduce considerably the security risks involved
  ! with allowing users to develop and run private CGI or SSI programs.  However,
  ! if suEXEC is improperly configured, it can cause any number of problems and
  ! possibly create new holes in your computer's security.  If you aren't familiar
  ! with managing setuid root programs and the security issues they present, we 
  ! highly recommend that you not consider using suEXEC.
  ! </P> 
  ! 
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
  ! 
  ! <H3><A NAME="before">Before we begin.</A></H3>
  ! <P ALIGN="LEFT">
  ! Before jumping head-first into this document, you should be aware of the
  ! assumptions made on the part of the Apache Group and this document.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! First, it is assumed that you are using a UNIX derivate operating system that
  ! is capable of <STRONG>setuid</STRONG> and <STRONG>setgid</STRONG> operations.
  ! All command examples are given in this regard.  Other platforms, if they are
  ! capable of supporting suEXEC, may differ in their configuration.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! Second, it is assumed you are familiar with some basic concepts of your 
  ! computer's security and its administration.  This involves an understanding
  ! of <STRONG>setuid/setgid</STRONG> operations and the various effects they
  ! may have on your system and its level of security.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! Third, it is assumed that you are using an <STRONG>unmodified</STRONG>
  ! version of suEXEC code.  All code for suEXEC has been carefully scrutinized and
  ! tested by the developers as well as numerous beta testers.  Every precaution has
  ! been taken to ensure a simple yet solidly safe base of code.  Altering this
  ! code can cause unexpected problems and new security risks.  It is 
  ! <STRONG>highly</STRONG> recommended you not alter the suEXEC code unless you 
  ! are well versed in the particulars of security programming and are willing to
  ! share your work with the Apache Group for consideration.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! Fourth, and last, it has been the decision of the Apache Group to 
  ! <STRONG>NOT</STRONG> make suEXEC part of the default installation of Apache.
  ! To this end, suEXEC configuration is a manual process requiring of the
  ! administrator careful attention to details.  It is through this process
  ! that the Apache Group hopes to limit suEXEC installation only to those
  ! who are determined to use it.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! Still with us?  Yes?  Good.  Let's move on!
  ! </P>
  ! 
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
  ! 
  ! <H3><A NAME="model">suEXEC Security Model</A></H3>
  ! <P ALIGN="LEFT">
  ! Before we begin configuring and installing suEXEC, we will first discuss
  ! the security model you are about to implement.  By doing so, you may
  ! better understand what exactly is going on inside suEXEC and what precautions
  ! are taken to ensure your system's security.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! <STRONG>suEXEC</STRONG> is based on a setuid "wrapper" program that is
  ! called by the main Apache web server.  This wrapper is called when an HTTP
  ! request is made for a CGI or SSI program that the administrator has designated
  ! to run as a userid other than that of the main server.  When such a request
  ! is made, Apache provides the suEXEC wrapper with the program's name and the 
  ! user and group IDs under which the program is to execute.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! The wrapper then employs the following process to determine success or
  ! failure -- if any one of these conditions fail, the program logs the failure
  ! and exits with an error, otherwise it will continue:
  ! 	<OL>
  ! 	<LI><STRONG>Was the wrapper called with the proper number of arguments?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	The wrapper will only execute if it is given the proper number of arguments.
  ! 	The proper argument format is known to the Apache web server.  If the wrapper
  ! 	is not receiving the proper number of arguments, it is either being hacked, or
  ! 	there is something wrong with the suEXEC portion of your Apache binary.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the user executing this wrapper a valid user of this system?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	This is to ensure that the user executing the wrapper is truly a user of the system.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is this valid user allowed to run the wrapper?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Is this user the user allowed to run this wrapper?  Only one user (the Apache
  ! 	user) is allowed to execute this program.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Does the target program have an unsafe hierarchical reference?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Does the target program contain a leading '/' or have a '..' backreference?  These
  ! 	are not allowed; the target program must reside within the Apache webspace.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target user name valid?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Does the target user exist?
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target group name valid?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Does the target group exist?
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target user <EM>NOT</EM> superuser?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Presently, suEXEC does not allow 'root' to execute CGI/SSI programs.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target userid <EM>ABOVE</EM> the minimum ID number?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	The minimum user ID number is specified during configuration.  This allows you
  ! 	to set the lowest possible userid that will be allowed to execute CGI/SSI programs.
  ! 	This is useful to block out "system" accounts.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target group <EM>NOT</EM> the superuser group?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Presently, suEXEC does not allow the 'root' group to execute CGI/SSI programs.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target groupid <EM>ABOVE</EM> the minimum ID number?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	The minimum group ID number is specified during configuration.  This allows you
  ! 	to set the lowest possible groupid that will be allowed to execute CGI/SSI programs.
  ! 	This is useful to block out "system" groups.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Can the wrapper successfully become the target user and group?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Here is where the program becomes the target user and group via setuid and setgid
  ! 	calls.  The group access list is also initialized with all of the groups of which
  ! 	the user is a member.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Does the directory in which the program resides exist?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	If it doesn't exist, it can't very well contain files.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the directory within the Apache webspace?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	If the request is for a regular portion of the server, is the requested directory
  ! 	within the server's document root?  If the request is for a UserDir, is the requested
  ! 	directory within the user's document root?
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the directory <EM>NOT</EM> writable by anyone else?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	We don't want to open up the directory to others; only the owner user may be able
  ! 	to alter this directories contents.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Does the target program exist?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	If it doesn't exists, it can't very well be executed.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target program <EM>NOT</EM> writable by anyone else?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	We don't want to give anyone other than the owner the ability to change the program.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target program <EM>NOT</EM> setuid or setgid?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	We do not want to execute programs that will then change our UID/GID again.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Is the target user/group the same as the program's user/group?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Is the user the owner of the file?
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Can we successfully clean the process environment to ensure safe operations?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	suEXEC cleans the process' environment by establishing a safe execution PATH (defined
  ! 	during configuration), as well as only passing through those variables whose names
  ! 	are listed in the safe environment list (also created during configuration).
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI><STRONG>Can we successfully become the target program and execute?</STRONG>
  ! 	<BLOCKQUOTE>
  ! 	Here is where suEXEC ends and the target program begins.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	</OL>
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! This is the standard operation of the the suEXEC wrapper's security model.
  ! It is somewhat stringent and can impose new limitations and guidelines for
  ! CGI/SSI design, but it was developed carefully step-by-step with security
  ! in mind.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! For more information as to how this security model can limit your possibilities
  ! in regards to server configuration, as well as what security risks can be avoided
  ! with a proper suEXEC setup, see the <A HREF="#beware">"Beware the Jabberwock"</A>
  ! section of this document.
  ! </P>
  ! 
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
  ! 
  ! <H3><A NAME="install">Configuring & Installing suEXEC</A></H3>
  ! <P ALIGN="LEFT">
  ! Here's where we begin the fun.  The configuration and installation of suEXEC is
  ! a four step process: edit the suEXEC header file, compile suEXEC, place the
  ! suEXEC binary in its proper location, and configure Apache for use with suEXEC.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! <STRONG>EDITING THE SUEXEC HEADER FILE</STRONG><BR>
  ! - From the top-level of the Apache source tree, type:&nbsp;&nbsp;
  ! <STRONG><code>cd support [ENTER]</code></STRONG>
  ! </P>
    
  ! <P ALIGN="LEFT">
    Edit the <code>suexec.h</code> file and change the following macros to
  ! match your local Apache installation.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
    <EM>From support/suexec.h</EM>
  ! <PRE>
  !      /*
  !       * HTTPD_USER -- Define as the username under which Apache normally
  !       *               runs.  This is the only user allowed to execute
  !       *               this program.
  !       */
  !      #define HTTPD_USER "www"
  ! 
  !      /*
  !       * UID_MIN -- Define this as the lowest UID allowed to be a target user
  !       *            for suEXEC.  For most systems, 500 or 100 is common.
  !       */
  !      #define UID_MIN 100
  ! 
  !      /*
  !       * GID_MIN -- Define this as the lowest GID allowed to be a target group
  !       *            for suEXEC.  For most systems, 100 is common.
  !       */
  !      #define GID_MIN 100
  ! 
  !      /*
  !       * USERDIR_SUFFIX -- Define to be the subdirectory under users' 
  !       *                   home directories where suEXEC access should
  !       *                   be allowed.  All executables under this directory
  !       *                   will be executable by suEXEC as the user so 
  !       *                   they should be "safe" programs.  If you are 
  !       *                   using a "simple" UserDir directive (ie. one 
  !       *                   without a "*" in it) this should be set to 
  !       *                   the same value.  suEXEC will not work properly
  !       *                   in cases where the UserDir directive points to 
  !       *                   a location that is not the same as the user's
  !       *                   home directory as referenced in the passwd file.
  !       *
  !       *                   If you have VirtualHosts with a different
  !       *                   UserDir for each, you will need to define them to
  !       *                   all reside in one parent directory; then name that
  !       *                   parent directory here.  IF THIS IS NOT DEFINED
  !       *                   PROPERLY, ~USERDIR CGI REQUESTS WILL NOT WORK!
  !       *                   See the suEXEC documentation for more detailed
  !       *                   information.
  !       */
  !      #define USERDIR_SUFFIX "public_html"
  ! 
  !      /*
  !       * LOG_EXEC -- Define this as a filename if you want all suEXEC
  !       *             transactions and errors logged for auditing and
  !       *             debugging purposes.
  !       */
  !      #define LOG_EXEC "/usr/local/etc/httpd/logs/cgi.log" /* Need me? */
  ! 
  !      /*
  !       * DOC_ROOT -- Define as the DocumentRoot set for Apache.  This
  !       *             will be the only hierarchy (aside from UserDirs)
  !       *             that can be used for suEXEC behavior.
  !       */
  !      #define DOC_ROOT "/usr/local/etc/httpd/htdocs"
  ! 
  !      /*
  !       * SAFE_PATH -- Define a safe PATH environment to pass to CGI executables.
  !       *
  !       */
  !      #define SAFE_PATH "/usr/local/bin:/usr/bin:/bin"
  ! </PRE>
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! <STRONG>COMPILING THE SUEXEC WRAPPER</STRONG><BR>
  ! You now need to compile the suEXEC wrapper.  At the shell command prompt, 
  ! type:&nbsp;&nbsp;<STRONG><CODE>cc suexec.c -o suexec [ENTER]</CODE></STRONG>.
    This should create the <STRONG><em>suexec</em></STRONG> wrapper executable.
  + </P>
    
  ! <P ALIGN="LEFT">
  ! <STRONG>COMPILING APACHE FOR USE WITH SUEXEC</STRONG><BR>
    By default, Apache is compiled to look for the suEXEC wrapper in the following
  ! location.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
    <EM>From src/httpd.h</EM>
  ! <PRE>
  !      /* The path to the suEXEC wrapper */
  !      #define SUEXEC_BIN "/usr/local/etc/httpd/sbin/suexec"
  ! </PRE>
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
    If your installation requires location of the wrapper program in a different
    directory, edit src/httpd.h and recompile your Apache server.
  ! See <A HREF="install.html">Compiling and Installing Apache</A> for more
  ! info on this process.
  ! </P>
    
  ! <P ALIGN="LEFT">
  ! <STRONG>COPYING THE SUEXEC BINARY TO ITS PROPER LOCATION</STRONG><BR>
    Copy the <STRONG><em>suexec</em></STRONG> executable created in the
  ! exercise above to the defined location for <STRONG>SUEXEC_BIN</STRONG>.
  ! </P>
    
  ! <P ALIGN="LEFT">
  ! <STRONG><CODE>cp suexec /usr/local/etc/httpd/sbin/suexec [ENTER]</CODE></STRONG>
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! In order for the wrapper to set the user ID, it must me installed as owner 
  ! <STRONG><em>root</em></STRONG> and must have the setuserid execution bit 
  ! set for file modes.  If you are not running a <STRONG><em>root</em></STRONG>
  ! user shell, do so now and execute the following commands.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! <STRONG><CODE>chown root /usr/local/etc/httpd/sbin/suexec [ENTER]</CODE></STRONG><BR>
  ! <STRONG><CODE>chmod 4711 /usr/local/etc/httpd/sbin/suexec [ENTER]</CODE></STRONG>
  ! </P>
  ! 
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
    
  ! <H3><A NAME="enable">Enabling & Disabling suEXEC</A></H3>
  ! <P ALIGN="LEFT">
    After properly installing the <STRONG>suexec</STRONG> wrapper
  ! executable, you must kill and restart the Apache server.  A simple
  ! <STRONG><CODE>kill -1 `cat httpd.pid`</CODE></STRONG> will not be enough.
    Upon startup of the web-server, if Apache finds a properly configured
    <STRONG>suexec</STRONG> wrapper, it will print the following message to
  ! the console:
  ! </P>
    
  ! <P ALIGN="LEFT">
  ! <CODE>Configuring Apache for use with suexec wrapper.</CODE>
  ! </P>
    
  + <P ALIGN="LEFT">
    If you don't see this message at server startup, the server is most
    likely not finding the wrapper program where it expects it, or the
  ! executable is not installed <STRONG><EM>setuid root</EM></STRONG>. Check
  ! your installation and try again.
  ! </P>
    
  + <P ALIGN="LEFT">
    One way to use <STRONG>suEXEC</STRONG> is through the
    <a href="mod/core.html#user"><STRONG>User</STRONG></a> and
    <a href="mod/core.html#group"><STRONG>Group</STRONG></a> directives in
  ***************
  *** 176,190 ****
    execution to be enabled for the user and that the script must meet the
    scrutiny of the <a href="#model">security checks</a> above.
    
  ! <hr>
    
  ! <h3>Debugging suEXEC</h3>
    The suEXEC wrapper will write log information to the location defined in
    the <code>suexec.h</code> as indicated above. If you feel you have
  ! configured and installed the wrapper properly,
  ! have a look at this log and the error_log for the server to see where
  ! you may have gone astray.
  ! <!--#include virtual="footer.html" -->
    
    </BODY>
    </HTML>
  --- 438,505 ----
    execution to be enabled for the user and that the script must meet the
    scrutiny of the <a href="#model">security checks</a> above.
    
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
    
  ! <H3><A NAME="debug">Debugging suEXEC</A></H3>
  ! <P ALIGN="LEFT">
    The suEXEC wrapper will write log information to the location defined in
    the <code>suexec.h</code> as indicated above. If you feel you have
  ! configured and installed the wrapper properly, have a look at this log 
  ! and the error_log for the server to see where you may have gone astray.
  ! </P>
  ! 
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
  ! 
  ! <H3><A NAME="jabberwock">Beware the Jabberwock: Warnings & Examples</A></H3>
  ! <P ALIGN="LEFT">
  ! <STRONG>NOTE!</STRONG>  This section may not be complete.  For the latest
  ! revision of this section of the documentation, see the Apache Group's
  ! <A HREF="http://www.apache.org/docs/suexec.html">Online Documentation</A>
  ! version.
  ! </P>
  ! 
  ! <P ALIGN="LEFT">
  ! There are a few points of interest regarding the wrapper that can cause
  ! limitations on server setup.  Please review these before submitting any
  ! "bugs" regarding suEXEC.
  ! <UL>
  ! 	<LH><STRONG>suEXEC Points Of Interest</STRONG></LH>
  ! 	<LI>Hierarchy limitations
  ! 	<BLOCKQUOTE>
  ! 	For security and efficiency reasons, all suexec requests must
  ! 	remain within either a top-level document root for virtual
  ! 	host requests, or one top-level personal document root for
  ! 	userdir requests.  For example, if you have four VirtualHosts
  ! 	configured, you would need to structure all of your VHosts'
  ! 	document roots off of one main Apache document hierarchy to
  ! 	take advantage of suEXEC for VirtualHosts. (Example forthcoming.)
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI>suEXEC's PATH environment variable
  ! 	<BLOCKQUOTE>
  ! 	This can be a dangerous thing to change.  Make certain every
  ! 	path you include in this define is a <STRONG>trusted</STRONG>
  ! 	directory.  You don't want to open people up to having someone
  ! 	from across the world running a trojan horse on them.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! 	<LI>Altering the suEXEC code
  ! 	<BLOCKQUOTE>
  ! 	Again, this can cause <STRONG>Big Trouble</STRONG> if you try
  ! 	this without knowing what you are doing.  Stay away from it
  ! 	if at all possible.
  ! 	</BLOCKQUOTE>
  ! 	</LI>
  ! </UL>
  ! 
  ! <P ALIGN="CENTER">
  ! <STRONG><A HREF="suexec.html">BACK TO CONTENTS</A></STRONG>
  ! </P>
    
  + <!--#include virtual="footer.html" -->
    </BODY>
    </HTML>