drush really loads the command line tool and runs it, so you can do this in the ~ / .curlrc file, but you need to make sure your commands are configured correctly.
leet@test:~$ cat ~/.curlrc
proxy = http://localhost:3128
Can be done with ...
echo -e "\n# Proxy manly for drush make\nproxy = http://localhost:3128 \n /
#Drush make work around for https \n
, . , , curlrc , bin, /etc/curl, .
, aegir.
, .