Enumerating Permissions can be Annoying
Don’t ask me how because I won’t tell you, but on one of the hosts I was testing on that did not allow direct access I was able to get the Apache server running as dhapache to erroneously write a file into my users blog directory. This is a big security no-no and I now have my .htaccess file written into the blog directory where it should go, but instead of my php script’s user having write access to the file so I can modify it, its owned by dhapache! Because the file is owned by dhapache I shouldn’t even be allowed to know it exists, but there it is. So the next step was to try and take ownership of the .htaccess file so that I could modify it. I tried and tried but was unsuccessful, I couldn’t modify it so that was another dead end. Actually it took me awhile to figure out how to remove the file from my directory. Being that it was owned by dhapache I couldn’t delete or modify it using my php process or even through ftp/ssh! Sysadmins regularly run find commands that search the servers for any files owned by dhapache that should not be there as this is a big red flag that someone has found a way to manipulate dhapache which could potentially lead to modifying dhapache-owned server config files, which sometimes is all it takes to hack your website and server.. Luckily I was able to delete it by basically running the hack again to overwrite the file.
WordPress
Unix file permissions are one of the more difficult subjects to grasp.. Well, ok maybe "grasp" isn't the word.. Master is the right word.. Unix file permissions is a hard topic to fully master, mainly I think because there aren't many instances when a computer user encounters them seriously, and bitwise is oldschool. This contains a listing of all possible permission masks and bits from a linux, php, and web hosting view.... cuz you guys AskApache Regs Rock!
Security chmod File Permissions umask
PHP's fsockopen function lets you open an Internet or Unix domain socket connection for connecting to a resource, and is one of the most powerful functions available in the php language.
PHP fsockopen PHP socket strace udp Unix
What they say about kung-fu is true..
It can be attained by anyone through hard work over time. You can become as good as the amount of work you put in. Here's a short look at a basic technique that I use. Simply reverse engineering the source code and taking notes along the way...
static void php_session_send_cookie(TSRMLS_D)
if (SG(headers_sent)) {
if (output_start_filename) {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot send session cookie - headers already sent by (output started at %s:%d)",
output_start_filename, output_start_lineno);
} else {
php_error_docref(NULL TSRMLS_CC, E_WARNING, "Cannot send session cookie - headers already sent");
}
return;
}
/* URL encode session_name and id because they might be user supplied */
e_session_name = php_url_encode(PS(session_name), strlen(PS(session_name)), NULL); PHP PHP Session Session ID
Host Google Analytics ga.js file locally for increased speed! Makes web pages load faster.
Google
PoshCSS.com has links to nice and new CSS Articles. Don't worry, they aren't snobs. ;)
CSS
CSS is one of the most useful tools I have in my toolbox as a Web Developer. Having a CSS Toolbox containing good CSS Classes that you repeatedly use is quite helpful for us XHTML / web-standards / best-practices developers. Check out 10 of my favorite CSS classes.
CSS
Check out this free online SEO site-scoring tool. The SEO generated report is simple, neat, and helpful. The main thing I like about it is how it is a stand-alone website, a residual money making machine.
Software
A lot of the past and upcoming articles on AskApache are focused on speeding up a server or website, or just making things more efficient. I'm starting several speed tip articles that require the following 3 programs if you want to follow along, that is... if you can keep up! ;)
Software
301 Redirects using Apache mod_rewrite or RedirectMatch in .htaccess or httpd.conf
Htaccess
Tons of awesome tips and tricks using netcat. Port redirector, nessus wrapper, capture exploits being sent by vuln scanners, etc. This is very useful for doing stuff like redirecting traffic through your firewall out to other places like web servers and mail hubs, while posing no risk to the firewall machine itself.
Security
Fighting Blog Spam with Apache htaccess and other methods.
Htaccess
Part deux of Want to know how to really hack? Originally Posted: 12/28/2003
Hacking
Comprehensive .htaccess example file with advanced examples in 1 htaccess sample skeleton .htaccess file with the very best apache htaccess examples... Updated frequently based on detailed info from the Apache htaccess tutorial.
Htaccess Allow AuthUserFile Deny Htaccess Redirect RewriteCond RewriteEngine RewriteRule
Play a tune directly on your pcspeaker right before the grub boot manager loads.
Linux GRUB GRUB_INIT_TUNE grub.cfg speaker