apt-get install libapache2-mod-auth-mysql
a2enmod auth_mysql

<Location />
        AuthName "Zionetrix Access"
        AuthType Basic
        AuthUserFile /dev/null
        AuthGroupFile /dev/null
        AuthBasicAuthoritative Off
        Auth_MySQL_Authoritative On
        Auth_MYSQL on
        Auth_MySQL_Host localhost
        Auth_MySQL_User myuser
        Auth_MySQL_Password mypassword
        Auth_MySQL_DB mydatabase
        Auth_MySQL_Password_Table users
        Auth_MySQL_Username_Field username
        Auth_MySQL_Password_Field password
        Auth_MySQL_Encryption_Types Crypt MD5
        Auth_MySQL_Password_Clause " AND allowed=1"
        require valid-user
</Location>

• /usr/share/doc/libapache2-mod-auth-mysql/USAGE.gz
• /usr/share/doc/libapache2-mod-auth-mysql/DIRECTIVES.gz