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# Apache [[MySQL]] Authentication for Debian Etch

This how-to describes the setup of redirecting the authentication of the Apache Web Server to a [[MySQL]] Database for Debian Etch.

Usually, this is done by Apache's _auth-mysql_ module. But, the relating Debian package _libapache2-mod-auth-myaql_ is currently not maintained and therefore not in the stable release (http://packages.qa.debian.org/liba/libapache-mod-auth-mysql.html).

There are two possible solutions:

* Using [[MySQL]] authentication via PAM

* Compiling the Apache module _auth-mysql_

Debian recommends to use PAM->MySQL authentication. It works fine, but the current Debian package does not support (non-crypt) MD5-password storage.

Thus, finally self-compiling the auth-mysql module appears to be the best solution. But, we have to pay attention to possible security advices concerning the module.

## PAM-MySQL Authentication

The recommended Debian way is to use the packages libapache2-mod-auth-pam and libpam-mysql instead.

~~~

# apt-get install libapache2-mod-auth-pam libpam-mysql

~~~

The usage of the PAM authentication module has to be configured in Apache2. To use [[MySQL]] authentication with our [[ShibbolethIdPInstallDebianEtch|IdP configuration]], we change the shibboleth authentication location in the idp configuration script as follows:

~~~

  <Location /shibboleth-idp/SSO>

    AuthPAM_Enabled 	on

    AuthPAM_FallThrough off

    AuthUserFile /dev/null

    AuthBasicAuthoritative Off

    AuthName               "Shibboleth IdP"

    AuthType               Basic

    require                valid-user

  </Location>

~~~

With regard to the security advice of the file "/usr/share/doc/libapache2-mod-auth-pam/README.Debian" 

~~~

SECURITY

  To use with standard Debian configuration you have to add "www-data" user to

  "shadow" group. Be careful! It means it can be readable by anyone who can run

  its own CGI script!

  The passwords are sent by net as clear text. You should use SSL to protect

  them.

~~~

we should add the user www-data to the shadow group.

~~~

# adduser www-data shadow

~~~

Next, we have to configure the PAM-MySQL module for Apache2.

Edit _/etc/pam.d/apache2_, add the following line setting the values such as they match your configuration

~~~

account required pam_mysql.so user=webadmin passwd=secret host=160.45.63.30 db=drupal5 table=_shared_users usercolumn=name passwdcolumn=pass crypt=1

~~~

More detailed information about the possible values can be retrieved reading _/usr/share/doc/libpam-mysql/README.gz_

~~~

# zless /usr/share/doc/libpam-mysql/README.gz

~~~

Finally, restart apache2 and see if it works.

## Compiling and Installing Apache's _auth-myaql_ module

Regarding this objective, we mainly rely on the following documentation http://forum.nuxwin.com/index.php/topic,736.msg3590.html#msg3590 (in french).

We need to install the following packages in order to compile and install the module:

~~~

 apt-get install apache2-prefork-dev libmysqlclient15-dev gcc patch

~~~

Create the directory _/usr/src/auth_mysql_ and change to it:

~~~

# mkdir /usr/src/auth_mysql

# cd /usr/src/auth_mysql

~~~

Download the module's source files and the relating patch for Apache 2.2

~~~

# wget http://download.nuxwin.com/apache2.2-modules/auth_mysql/mod_auth_mysql-3.0.0.tar.gz

# wget http://download.nuxwin.com/apache2.2-modules/auth_mysql/patch/apache2.2.diff

~~~

Unpack the sources and apply the patch file to the sources:

~~~

tar xzf mod_auth_mysql-3.0.0.tar.gz

# cp apache2.2.diff mod_auth_mysql-3.0.0/

# cd mod_auth_mysql-3.0.0

# patch -p0 < apache2.2.diff mod_auth_mysql.c

~~~

Compiling the module and check the output produced:

~~~

# apxs2 -c -L/usr/lib/mysql -I/usr/include/mysql -lmysqlclient -lm -lz mod_auth_mysql.c

/usr/share/apr-1.0/build/libtool --silent --mode=compile --tag=disable-static i486-linux-gnu-gcc -prefer-pic -D_GNU_SOURCE -D_LARGEFILE64_SOURCE -DLINUX=2 -D_REENTRANT -I/usr/include/apr-1.0 -I/usr/include/openssl -I/usr/include/postgresql -I/usr/include/xmltok -pthread     -I/usr/include/apache2  -I/usr/include/apr-1.0   -I/usr/include/apr-1.0 -I/usr/include/postgresql -I/usr/include/mysql  -c -o mod_auth_mysql.lo mod_auth_mysql.c && touch mod_auth_mysql.slo

/usr/share/apr-1.0/build/libtool --silent --mode=link --tag=disable-static i486-linux-gnu-gcc -o mod_auth_mysql.la  -L/usr/lib/mysql -lmysqlclient -lm -lz -rpath /usr/lib/apache2/modules -module -avoid-version    mod_auth_mysql.lo

~~~

Install the module and check the output produced:

@-LLIBDIR'

flag during linking and do at least one of the following:

   - add LIBDIR to the @

Create the module's load configuration file:

~~~

# echo "LoadModule mysql_auth_module /usr/lib/apache2/modules/mod_auth_mysql.so" > /etc/apache2/mods-available/auth_mysql.load

~~~

Enable the module and restart apache2:

~~~

# a2enmod auth_mysql

# /etc/init.d/apache2 force-reload

~~~

You can check your configuration observing the following log-files

* /var/log/apache2/access.log

* /var/log/apache2/error.log

* /var/log/auth.log