Apache Setup Receipe for ZXID

Sampo Kellomäki (sampo@iki.fi)

While I am not a guru in Apache set ups and others will do this much better, not to speak of the official documentation, I still find that to ensure initial success of the new installer, some help may be in order.

Consider this receipe only one of many possible setups and not necessarily even the best. The receipe worked for me in August 2006. If you come much later, things may have changed.

This Apache setup aims to illustrate

If you are looking for mod_auth_saml specific instructions, please read Apache with mod_auth_saml Receipe.

For more general information about ZXID.org compilation or APIs start reading in README.zxid.

1 Architectural Overview


Fig-1: ZXID, via mod_auth_saml, adds to Apache httpd Single Sign-On (SSO), Attribute Broker, and XACML PEP Capabilities that can be used by existing static and dynamic content without alteration.

2 Compiling from Source

You may also install from binaries, but I feel the compilation route is only reliable way to have reproducible results.

2.1 apache httpd-2.2.3

Download from: http://httpd.apache.org/download.cgi

For PHP it is critical that --enable-so is supplied as that seems to be the only documented (supported?) installation route. PHP recommends (Aug 2006) against using Apache 2 threaded MPM. My stock perl does not support threads either, I guess the prefork MPM route is fine.

  tar xvjf /t/httpd-2.2.3.tar.bz2
  ./configure --prefix=/apps/apache/2.2.3 --with-mpm=prefork --enable-so --enable-cgi --disable-cgid --enable-ssl --with-ssl=/apps/openssl/std

I got following configure error

  checking for SSL_set_cert_store... no

This seems to be documented as bug http://issues.apache.org/bugzilla/show_bug.cgi?id=39913, but no solution was known as of Aug 2006. Further investigation shows that httpd-2.2.3/modules/ssl/README has following

   o per-directory SSLCACertificate{File,Path} is now thread-safe but
     requires SSL_set_cert_store patch to OpenSSL

but fails to provide the patch or give any hint as to how to obtain it.

Apparently hacking the configure script to remove all references to the offending variable in question is the only way forward. Look at config.log to identify the places to hack. Iterate ./configure script until it works and then say

  make

A couple of linking failures dues to missing -lz happen. Just run the links manually, supplying the -lz flag. Sheesh, apache is supposed to be stable software.

  make install

2.2 perl-5.8.8

From http://ftp.funet.fi/pub/CPAN/src/

This can be usually skipped if your stock perl is 5.8 series and nonthreaded and you are happy with prefork MPM. Try

  perl -V:useithreads -V:usemultiplicity

If it says

  useithreads='undef';
  usemultiplicity='undef';

then its fine for using prefork MPM.

To compile perl you would

  ./Configure -prefix=/apps/perl/5.8.8 -des -Dusethreads -Doptimize='-g' -Dusedevel
  make && make test && make install

2.3 mod_perl-2.0.4

From http://perl.apache.org/dist/

Install instructions: http://perl.apache.org/docs/2.0/user/install/install.html

tar xvf /t/mod_perl-2.0.4.tar.gz

  perl Makefile.PL MP_APXS=/apps/apache/std/bin/apxs MP_DEBUG=1
  make
  make test
  # Seems to fail because wants to create core files and I do not let it to!
  make install
  # installs stuff to perl lib directory as well as apache modules directory

You can read futher at http://perl.apache.org/docs/2.0/user/intro/start_fast.html

2.4 php-5.1.6

From php.net

Install instructions: http://www.php.net/manual/en/install.unix.apache2.php

  ./configure --prefix=/apps/php/5.1.6 --with-apxs2=/apps/apache/std/bin/apxs --with-openssl=/apps/openssl/std --with-zlib --with-curl=/apps --enable-soap --with-libxml-dir=/apps
  make
  make install

3 Configuring Apache

These configuration steps are to enable all ZXID Apache related functionality, including mod_auth_saml, mod_perl, mod_php, and CGI.

Once you have edited the Apache config files, you say

  /apps/apache/std/bin/apachectl restart
  tail -f tmp/err-httpd &   # Apache errorlog, per configuration

to get apache running. Below are the edits I applied to my apache config files (in /apps/apache/std/conf directory if you followed this receipe). It's a shame the apache config wizardry is so bloated that the diff does not fit on one page. Also distributions with an attitude tend to complicate apache configuration files further by pulverizing them in many files over many directories. Some of the known distribution locations

  /etc/apache2/sites-available/default   # Ubuntu ca. 2009
diff -u /apps/apache/std/conf/httpd.conf.orig /apps/apache/std/conf/httpd.conf
--- httpd.conf.orig     2006-08-31 19:23:42.000000000 -0400
+++ httpd.conf  2006-08-31 20:31:17.000000000 -0400
@@ -37,7 +37,8 @@
 # prevent Apache from glomming onto all bound IP addresses.
 #
 #Listen 12.34.56.78:80
-Listen 80
+##Listen 80
+Listen 8080
 
 #
 # Dynamic Shared Object (DSO) Support
@@ -51,6 +52,8 @@
 # Example:
 # LoadModule foo_module modules/mod_foo.so
 #
+LoadModule perl_module modules/mod_perl.so
+LoadModule php5_module modules/libphp5.so
 
 
 #
@@ -98,7 +101,8 @@
 # documents. By default, all requests are taken from this directory, but
 # symbolic links and aliases may be used to point to other locations.
 #
-DocumentRoot "/apps/apache/2.2.3/htdocs"
+##DocumentRoot "/apps/apache/2.2.3/htdocs"
+DocumentRoot "/home/sampo/zxid"
 
 #
 # Each directory to which Apache has access can be configured with respect
@@ -125,7 +129,8 @@
 #
 # This should be changed to whatever you set DocumentRoot to.
 #
-
+##
+
     #
     # Possible values for the Options directive are "None", "All",
     # or any combination of:
@@ -138,7 +143,13 @@
     # http://httpd.apache.org/docs/2.2/mod/core.html#options
     # for more information.
     #
-    Options Indexes FollowSymLinks
+    ##Options Indexes FollowSymLinks
+    Options All
+
+    AddHandler cgi-script .cgi
+    AddHandler perl-script .pl
+    PerlResponseHandler ModPerl::Registry
+    PerlOptions +ParseHeaders
 
     #
     # AllowOverride controls what directives may be placed in .htaccess files.
@@ -155,6 +166,10 @@
 
 
 
+
+SetHandler cgi-script
+
+
 #
 # DirectoryIndex: sets the file that Apache will serve if a directory
 # is requested.
@@ -180,14 +195,16 @@
 # logged here.  If you *do* define an error logfile for a 
 # container, that host's errors will be logged there and not here.
 #
-ErrorLog logs/error_log
+##ErrorLog logs/error_log
+ErrorLog /home/sampo/zxid/tmp/err-httpd
 
 #
 # LogLevel: Control the number of messages logged to the error_log.
 # Possible values include: debug, info, notice, warn, error, crit,
 # alert, emerg.
 #
-LogLevel warn
+##LogLevel warn
+LogLevel debug
 
 
     #
@@ -209,13 +226,14 @@
     # define per- access logfiles, transactions will be
     # logged therein and *not* in this file.
     #
-    CustomLog logs/access_log common
+    ##CustomLog logs/access_log common
 
     #
     # If you prefer a logfile with access, agent, and referer information
     # (Combined Logfile Format) you can use the following directive.
     #
     #CustomLog logs/access_log combined
+    CustomLog /home/sampo/zxid/tmp/log.httpd combined
 
 
 
@@ -245,7 +263,7 @@
     # client.  The same rules about trailing "/" apply to ScriptAlias
     # directives as to Alias.
     #
-    ScriptAlias /cgi-bin/ "/apps/apache/2.2.3/cgi-bin/"
+    ##ScriptAlias /cgi-bin/ "/apps/apache/2.2.3/cgi-bin/"
 
 
 
@@ -303,7 +321,7 @@
     #
     AddType application/x-compress .Z
     AddType application/x-gzip .gz .tgz
-
+AddType application/x-httpd-php .php .phtml
     #
     # AddHandler allows you to map certain file extensions to "handlers":
     # actions unrelated to filetype. These can be either built into the server
@@ -394,7 +412,7 @@
 #Include conf/extra/httpd-default.conf
 
 # Secure (SSL/TLS) connections
-#Include conf/extra/httpd-ssl.conf
+Include conf/extra/httpd-ssl.conf
 #
 # Note: The following must must be present to support
 #       starting without SSL on platforms with no /dev/random equivalent

diff -u httpd-ssl.conf.orig httpd-ssl.conf
--- httpd-ssl.conf~     2006-08-31 18:24:09.000000000 -0400
+++ httpd-ssl.conf      2006-08-31 19:35:53.000000000 -0400
@@ -22,9 +22,9 @@
 # Manual for more details.
 #
 #SSLRandomSeed startup file:/dev/random  512
-#SSLRandomSeed startup file:/dev/urandom 512
+SSLRandomSeed startup file:/dev/urandom 512
 #SSLRandomSeed connect file:/dev/random  512
-#SSLRandomSeed connect file:/dev/urandom 512
+SSLRandomSeed connect file:/dev/urandom 512
 
 
 #
@@ -34,7 +34,7 @@
 # Note: Configurations that use IPv6 but not IPv4-mapped addresses need two
 #       Listen directives: "Listen [::]:443" and "Listen 0.0.0.0:443"
 #
-Listen 443
+Listen 5443
 
 ##
 ##  SSL Global Context
@@ -71,14 +71,16 @@
 ## SSL Virtual Host Context
 ##
 
-
+
 
 #   General setup for the virtual host
-DocumentRoot "/apps/apache/2.2.3/htdocs"
-ServerName www.example.com:443
+##DocumentRoot "/apps/apache/2.2.3/htdocs"
+DocumentRoot "/home/sampo/zxid"
+##ServerName www.example.com:443
+ServerName sp1.zxidsp.org:443
 ServerAdmin you@example.com
-ErrorLog /apps/apache/2.2.3/logs/error_log
-TransferLog /apps/apache/2.2.3/logs/access_log
+##ErrorLog /apps/apache/2.2.3/logs/error_log
+##TransferLog /apps/apache/2.2.3/logs/access_log
 
 #   SSL Engine Switch:
 #   Enable/Disable SSL for this virtual host.
@@ -96,15 +98,16 @@
 #   in mind that if you have both an RSA and a DSA certificate you
 #   can configure both in parallel (to also allow the use of DSA
 #   ciphers, etc.)
-SSLCertificateFile /apps/apache/2.2.3/conf/server.crt
+##SSLCertificateFile /apps/apache/2.2.3/conf/server.crt
 #SSLCertificateFile /apps/apache/2.2.3/conf/server-dsa.crt
+SSLCertificateFile /home/sampo/zxid/zxid.pem
 
 #   Server Private Key:
 #   If the key is not combined with the certificate, use this
 #   directive to point at the key file.  Keep in mind that if
 #   you've both a RSA and a DSA private key you can configure
 #   both in parallel (to also allow the use of DSA ciphers, etc.)
-SSLCertificateKeyFile /apps/apache/2.2.3/conf/server.key
+##SSLCertificateKeyFile /apps/apache/2.2.3/conf/server.key
 #SSLCertificateKeyFile /apps/apache/2.2.3/conf/server-dsa.key
 
 #   Server Certificate Chain:
@@ -225,7 +228,7 @@
 #   Per-Server Logging:
 #   The home of a custom SSL log file. Use this when you want a
 #   compact non-error SSL logfile on a virtual host basis.
-CustomLog /apps/apache/2.2.3/logs/ssl_request_log \
-          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
+#CustomLog /apps/apache/2.2.3/logs/ssl_request_log \
+#          "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
 
                                   

4 Trying Out Apache

Check sp1.zxidsp.org resolves

  ping sp1.zxidsp.org

Start Apache httpd using

  apachectl restart

or possibly some other distribution dependent way

  apache2ctl restart
  sudo invoke-rc.d apache2 restart   # Ubuntu ca. 2009

At this stage you should observe carefully for any unresolved symbols or missing shared libraries (.so) (or dynamic link libraries, DLLs). If you see any, you need to resolve them, e.g. by setting LD_LIBRARY_PATH environment variable.

Now, use browser to access following URLs to try your accomplishments out:

  1. https://sp1.zxidsp.org:5443/README.zxid tests (tests simple file access and that the server works at all)

  2. https://sp1.zxidsp.org:5443/zxid?o=E (tests the SP CGI written in C)

  3. https://sp1.zxidsp.org:5443/zxid.pl?o=E (tests the SP mod_perl way)

  4. https://sp1.zxidsp.org:5443/zxid.php?o=E (tests the SP mod_php5 way)

  5. https://sp1.zxidsp.org:5443/protected/content.txt

If any of the above does not work, be sure to inspect the apache logs (be sure to replace /home/sampo with whatever makes sense):

  tail -f /home/sampo/zxid/tmp/err-httpd

If you can't get any access at all, be sure you do not have the mini_httpd or some other process running on the same port.

Also make sure the execute permission is set for any CGI scripts, e.g:

  chmod a+x zxid.pl

5 Debugging Apache Cores

mod_auth_saml, mod_php, or mod_perl with Net::SAML can crash in C code. That can be debugged using this receipe. If using all three simultaneously, beware of version discrepancy: a newer module can pick up libzxid symbols from an older module. This leads to rather confusing "warning: Source file is more recent than executable."

tail -f tmp/log.httpd &
tail -f tmp/err-httpd &
ulimit -c unlimited
/apps/apache/std/bin/httpd -X    # Run Apache in single threaded debug mode
gdb /apps/apache/std/bin/httpd /d/sampo/zxid/core

6 Conclusion

If you have any trouble, please do not hesitate to contact the author.

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