Installation of Linux PAM
        
        
          If you downloaded the documentation, unpack the tarball by issuing
          the following command.
        
        
tar -xf ../Linux-PAM-1.1.8-docs.tar.bz2 --strip-components=1
        
          Install Linux PAM by running the
          following commands:
        
        
./configure --prefix=/usr \
            --sysconfdir=/etc \
            --libdir=/usr/lib \
            --enable-securedir=/lib/security \
            --docdir=/usr/share/doc/Linux-PAM-1.1.8 &&
make
        
          To test the results, a suitable /etc/pam.d/other configuration file must exist.
        
        
          ![[Caution]](../images/caution.png) 
          
            Reinstallation or upgrade of Linux PAM
          
          
            If you have a system with Linux PAM installed and working, be
            careful when modifying the files in /etc/pam.d, since your system may become
            totally unusable. If you want to run the tests, you do not need
            to create another /etc/pam.d/other
            file. The installed one can be used for that purpose.
          
          
            You should also be aware that make
            install overwrites the configuration files in
            /etc/security as well as
            /etc/environment. In case you have
            modified those files, be sure to backup them.
          
         
        
          For a first installation, create the configuration file by issuing
          the following commands as the root
          user:
        
        
install -v -m755 -d /etc/pam.d &&
cat > /etc/pam.d/other << "EOF"
auth     required       pam_deny.so
account  required       pam_deny.so
password required       pam_deny.so
session  required       pam_deny.so
EOF
        
          Now run the tests by issuing make
          check. Ensure there are no errors produced by the
          tests before continuing the installation.
        
        
          Only in case of a first installation, remove the configuration file
          created earlier by issuing the following command as the
          root user:
        
        
rm -rfv /etc/pam.d
        
          Now, as the root user:
        
        
make install &&
chmod -v 4755 /sbin/unix_chkpwd &&
for file in pam pam_misc pamc
do
  mv -v /usr/lib/lib${file}.so.* /lib &&
  ln -sfv ../../lib/$(readlink /usr/lib/lib${file}.so) /usr/lib/lib${file}.so
done
       
      
        
          Command Explanations
        
        
          --enable-securedir=/lib/security:
          This switch sets install location for the PAM modules.
        
        
          chmod -v 4755
          /sbin/unix_chkpwd: The unix_chkpwd helper program must
          be setuid so that non-root
          processes can access the shadow file.
        
       
      
        
          Configuring Linux-PAM
        
        
          
            Config Files
          
          
            /etc/security/* and /etc/pam.d/*
          
         
        
          
            Configuration Information
          
          
            Configuration information is placed in /etc/pam.d/. Below is an example file:
          
          
# Begin /etc/pam.d/other
auth            required        pam_unix.so     nullok
account         required        pam_unix.so
session         required        pam_unix.so
password        required        pam_unix.so     nullok
# End /etc/pam.d/other
          
            The PAM man page (man pam) provides a good
            starting point for descriptions of fields and allowable entries.
            The Linux-PAM
            System Administrators' Guide is recommended for additional
            information.
          
          
            Refer to 
            http://debian.securedservers.com/kernel/pub/linux/libs/pam/modules.html
            for a list of various third-party modules available.
          
          
            ![[Important]](../images/important.png) 
            
              Important
            
            
              You should now reinstall the Shadow-4.2.1 package.