Set dovecot to generate 2048 bit dhparams on a cPanel/WHM box.

cpanel-strengthen-dhparams-in-dovecot.sh

#!/bin/sh

# if no local config for dovecot exists, make one
if[ ! -e /var/cpanel/templates/dovecot2.2/main.local ]; then
  cp /var/cpanel/templates/dovecot2.2/main.default /var/cpanel/templates/dovecot2.2/main.local
fi

# check if ssl_dh_parameters exists already. if it doesn't exist, insert it
if [ -z "$(grep "ssl_dh_parameters_length" /var/cpanel/templates/dovecot2.2/main.local)" ]; then
  sed -i '/ssl = \[% ssl %\]/,/\[%- ELSE %\]/ {/\[%- ELSE %\]/i ssl_dh_parameters_length = 2048}' /var/cpanel/templates/dovecot2.2/main.local
fi

# rebuild, and restart dovecot to apply changes
/usr/local/cpanel/scripts/builddovecotconf
/scripts/restartsrv_dovecot