Archive for the linux Category

EnvironmentError: The environment options "TRAC_ENV" or "TRAC_ENV_PARENT_DIR"
or the mod_python options "TracEnv" or "TracEnvParentDir" are missing.

Yuck. What’s more, if you’re using SuExec (like I am) then your Apache directives are ignored.

Solution: Edit your trac.fcgi and prepend the following code.

# hack for SuExec
import os;
os.environ['TRAC_ENV_PARENT_DIR'] = ‘/var/lib/trac’

Some vulnerabilities in the Linux kernel where publicly disclosed on the 8th of February 2008. These can be exploited by any user to gain elevated privileges. A “local root” exploit was published Sunday which allows an arbitrary user to escalate to root privileges.

Affected versions: >= 2.6.17
Fixed in version: 2.6.24.2
(more…)

truecrypt_windows.png
truecrypt_osx.png
truecrypt_linux.png
Finally we have a truly portable, open source, encrypted filesystem. I’ve tested a fair share of encrypted filesystem solutions. The most promising probably being encfs since it could be used with Fuse, but that only works on OS X and Linux at best.

TrueCrypt, probably the best solution available, was only working on Linux and Windows… up to now.
(more…)

But that’s impossible!!

HTTPS is just HTTP encapsulated inside an SSL tunnel. Apache’s virtual hosts are a clever “hack” whereby the Host header in the HTTP packet is verified. This alllows a single apache instance on a single IP/Port combination to serve a (not so) infinite number of differentes sites (aka vhosts).

Problem: The SSL tunnel is created before the first HTTP packet gets sent. Apache needs an SSL certificate but doesn’t have a Host header to match, hence cannot choose a virtual host.

Solution

This trick essentially does the matching of the Host header after the SSL connection has been established. How? Via some mod_rewrite magic!

Caveats

Although I said so, it’s not really that magical. There are a few things this trick does not solve.

  • The SSL certificate used will be common to all SSL vhosts.
  • Certain Apache directives may be common to all SSL vhosts (example: SuExecUserGroup). Basically anything you can’t override in a .htaccess file will be shared amongst vhosts.

(more…)