Using Pluggable Authentication Modules (PAM) with OpenACS

OpenACS supports PAM authetication via the ns_pam module in AOLserver.

  1. Add PAM support to AOLserver. OpenACS supports PAM support via the PAM AOLserver module. PAM is system of modular support, and can provide local (unix password), RADIUS, LDAP (more information), and other forms of authentication. Note that due to security issues, the AOLserver PAM module cannot be used for local password authentication.

    1. Compile and install ns_pam. Download the tarball to /tmp.

      Debian users: first do apt-get install libpam-dev

      [root@yourserver root]# cd /usr/local/src/aolserver
      [root@yourserver aolserver]# tar xzf /tmp/ns_pam-0.1.tar.gz
      [root@yourserver aolserver]# cd nspam
      [root@yourserver nspam]# make
      gcc -I/usr/include/pam -I/usr/local/aolserver/include -D_REENTRANT=1 
        -DNDEBUG=1 -g -fPIC -Wall -Wno-unused -mcpu=i686 -DHAVE_CMMSG=1 
        -DUSE_FIONREAD=1 -DHAVE_COND_EINTR=1   -c -o nspam.o nspam.c
      nspam.c: In function `PamCmd':
      nspam.c:107: warning: implicit declaration of function `Tcl_SetObjResult'
      nspam.c:107: warning: implicit declaration of function `Tcl_NewIntObj'
      gcc -I/usr/include/pam -I/usr/local/aolserver/include -D_REENTRANT=1 
        -DNDEBUG=1 -g -fPIC -Wall -Wno-unused -mcpu=i686 -DHAVE_CMMSG=1 
        -DUSE_FIONREAD=1 -DHAVE_COND_EINTR=1   -c -o pam_support.o pam_support.c
      /bin/rm -f nspam.so
      gcc -shared -nostartfiles -o nspam.so nspam.o pam_support.o -lpam
      [root@yourserver nspam]# make install
      [root@yourserver nspam]#
      cd /usr/local/src/aolserver
      tar xzf /tmp/ns_pam-0.1.tar.gz
      cd nspam
      make
      make install
      
    2. Set up a PAM domain. A PAM domain is a set of rules for granting privileges based on other programs. Each instance of AOLserver uses a domain; different aolserver instances can use the same domain but one AOLserver instance cannot use two domains. The domain describes which intermediate programs will be used to check permissions. You may need to install software to perform new types of authentication.

      • RADIUS in PAM. 

        1. Untar the pam_radius tarball and compile and install. (more information)

          [root@yourserver root]# cd /usr/local/src/
          [root@yourserver src]# tar xf /tmp/pam_radius-1.3.16.tar
          [root@yourserver src]# cd pam_radius-1.3.16
          [root@yourserver pam_radius-1.3.16]# make
          cc -Wall -fPIC -c pam_radius_auth.c -o pam_radius_auth.o
          cc -Wall -fPIC   -c -o md5.o md5.c
          ld -Bshareable pam_radius_auth.o md5.o -lpam -o pam_radius_auth.so
          [root@yourserver pam_radius-1.3.16]# cp pam_radius_auth.so /lib/security/pam_radius_auth.so
          [root@yourserver pam_radius-1.3.16]#
          cd /usr/local/src/
          tar xf /tmp/pam_radius-1.3.16.tar
          cd pam_radius-1.3.16
          make
          cp pam_radius_auth.so /lib/security/pam_radius_auth.so
          

          Debian users: apt-get install libpam-radius-auth

        2. Set up the PAM domain. Recent PAM distributions have a different file for each domain, all in /etc/pam.d. Previous PAM setups put all domain configuration lines into a single file, /etc/pam.conf. On Red Hat, create the file /etc/pam.d/service0 with these contents:

          auth       sufficient   /lib/security/pam_radius_auth.so
          
        3. Modify the AOLserver configuration file to use this PAM domain. Edit the line

          ns_param   PamDomain             "service0"
          

          So that the value of the parameter matches the name (just the file name, not the fully pathed name) of the domain file in

          /etc/pam.d/
          
      • LDAP in PAM. more information

    3. Modify the AOLserver configuration file to support ns_pam. 

      In /var/lib/aolserver/service0/etc/config.tcl, enable the nspam module by uncommenting this line:

      ns_param   nspam           ${bindir}/nspam.so
      
  2. Install auth-pam OpenACS service package. Installauth-pam and restart the server.

  3. Create an OpenACS authority. OpenACS supports multiple authentication authorities. The OpenACS server itself is the "Local Authority," used by default.

    1. Browse to the authentication administration page, http://yourserver/acs-admin/auth/ . Create and name an authority (in the sitewide admin UI)

    2. Set Authentication to PAM.

    3. If the PAM domain defines a password command, you can set Password Management to PAM. If not, the PAM module cannot change the user's password and you should leave this option Disabled.

    4. Leave Account Registration disabed.

    5. Configure Batch Synchronization