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
While researching a unix/linux tool awk I came upon one of the most thorough and helpful tutorials I've ever seen devoted to a particular topic. It's old-school just the way I like it. I contacted the author, Bruce Barnett because I just HAD to have this article for my readers, who are predominantly running solaris/unix/bsd/linux and he kindly gave permission.
Linux
If you have a php.cgi or php.ini file in your /cgi-bin/ directory or other pub directory, try requesting them from your web browser. If your php.ini shows up or worse you are able to execute your php cgi, you'll need to secure it ASAP. This shows several ways to secure these files, and other interpreters like perl, fastCGI, bash, csh, etc.
Htaccess Apache HTTP Server CGI Common Gateway Interface Htaccess HTTP 403 interpreter PHP php interpreter php.ini security SuEXEC
One of the first things that I do upon receiving a new Windows computer is immediately create a poweruser-style customized boot menu. Then every time I boot I can choose Safe Mode, Recovery Console, Debug, whatever I want! It's quick and easy to set-up and everyone should have one, soo sweet!
Windows
Hacking Cheat sheet linux
To prepare for several upcoming articles on AskApache that are focused on optimizing Servers and Sites from a server admin level, here is an article to introduce the main tools that we will be using. These tools are used to optimize CPU time for each process using nice and renice, and other tools like ionice are used to optimize the Disk IO, or Disk speed / Disk traffic for each process. Then you can make sure your mysqld and httpd processes are always fast and prioritized.
Optimization CFQ Idle linux Linux scheduler Load Nice RAM Scheduling algorithms
Here's the problem I was having while working on a custom theme for a client. Certain pages, posts, tag pages, archive pages, and custom pages either had the sidebar, or did not have the sidebar. The main content div #ContentW had a 72% width when the sidebar was present, otherwise it was 96%. The problem was that I dislike having to do things manually when they can be automated through code. What I was having to do was manually add/remove page-specific classes to the css file to reflect whether the sidebar was present on that page or not.
WordPress Sidebar wordpress
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
This amazing bash linux prompt does more than meets the eye. If you want to know how to become really good with technology, linux is the secret sauce behind the AskApache articles. Open Source is elixir of the web. Thanks to everyone who helped me for the past 20 years. I use linux/bsd because homey don't play, so this is geared to be as productive a prompt as I can make it.
Don't have much time.. or just don't care? Not a problem, here are the 3 lines to copy and paste - you can just paste them right in your shell to test it, or add to a startup script.
export AA_P="export PVE=\"\\033[m\\033[38;5;2m\"\$(( \`sed -n \"s/MemFree:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\` / 1024 ))\"\\033[38;5;22m/\"\$((\`sed -n \"s/MemTotal:[\\t ]\\+\\([0-9]\\+\\) kB/\\1/p\" /proc/meminfo\`/ 1024 ))MB\"\\t\\033[m\\033[38;5;55m\$(< /proc/loadavg)\\033[m\";echo -en \"\""
export PROMPT_COMMAND="history -a;((\$SECONDS % 10==0 ))&&eval \"\$AA_P\";echo -en \"\$PVE\";"
export PS1="\\[\\e[m\\n\\e[1;30m\\][\$\$:\$PPID \\j:\\!\\[\\e[1;30m\\]]\\[\\e[0;36m\\] \\T \\d \\[\\e[1;30m\\][\\[\\e[1;34m\\]\\u@\\H\\[\\e[1;30m\\]:\\[\\e[0;37m\\]\${SSH_TTY} \\[\\e[0;32m\\]+\${SHLVL}\\[\\e[1;30m\\]] \\[\\e[1;37m\\]\\w\\[\\e[0;37m\\] \\n(\$SHLVL:\\!)\\\$ " && eval $AA_P Linux bash Prompt PROMPT_COMMAND PS1 sed ssh
.htaccess is a very ancient configuration file for web servers, and is one of the most powerful configuration files most webmasters will ever come across. This htaccess guide shows off the very best of the best htaccess tricks and code snippets from hackers and server administrators.
You've come to the right place if you are looking to acquire mad skills for using .htaccess files!
Apache, Hosting, Htaccess, Optimization, Security, SEO, Web Development, WordPress .htpasswd 301 Redirect Apache Apache HTTP Server Cache Hosting Htaccess Htaccess Software HTTP Headers httpd.conf HyperText Transfer Protocol mod_rewrite Redirect RewriteCond RewriteRule SSL
Apache Security tips and tricks for securing Apache Web Servers using htaccess, httpd.conf, and other built-in techniques to thwart attackers. This really should be required reading for any Apache admin or user because these little tricks are so easy to do.
Htaccess
As a security nut myself, and also a Linux admin, one of my biggest pet peeves is when I've taken the time and care to segment all the users on a server into separate home directories, and then some developer comes along, logs in as root, and changes the ownership of files. Other things can cause this, like Apache, PHP, Mutt, etc.. So I've always used a cron job that executes daily (and on demand) which automatically fixes all the permissions back to what they should be.
Linux bash chmod chown cron linux permissions shell
A souped-up version of the Apache printenv script for hard-core server environment debuggery.
#!/bin/sh
echo -e "Content-type: text/plainnn"
...
__T "CURRENT PROCESS CMDLINE"
{
for p in `echo /proc/[0-9]*/cmdline`;
do
pid=${p:6:$((${#p}-13))}
[[ $pid == $PPID || $pid == $$ ]] && continue;
__M "[ /proc/$pid ]";
sed 's/x00/ /g;G' $p 2>/dev/null
done
}
fi Hosting Apache HTTP Server Apache server CGI Common Gateway Interface Htaccess
The bottom line for this article is that I want to make WordPress as fast, secure, and easy to install, run, and manage because I am using it more and more for client production sites, I will work for days in order to solve an issue so that I never have to spend time on that issue again. Time is money in this industry and that is ultimately (time) what there is to gain by tweaking WordPress.
Note: I spent no time on readability, this is primarily a read the code and figure it out article.. This is for advanced users looking for a reference or discussion and for those of you looking to advance. Feedback would be great if you make it that far..
WordPress wordpress wp-config.php
Using memcache for me personally and the client sites I work on, has improved performance by over 1000%, in some cases even higher than that. It is a truly revolutionary way to optimize the performance of MySQL queries, remote requests such as to twitter or other apis, and this article is step 1. Plan is to go all the way to step 10 in future articles, it it grossly underused and misused in the WP world.
Optimization, WordPress Cache Load memcache memcached performance server speed
SSLOptions +StrictRequire
SSLRequireSSL
SSLRequire %{HTTP_HOST} eq "google.com"
ErrorDocument 403 https://google.com
Some of the Ins and Outs of using SSL Connections with Apache.
Htaccess 301 Redirects Htaccess mod_rewrite SSL
3-Part article covering practical implementation of 3 advanced .htaccess features. Discover an easy way to boost your SEO the AskApache way (focus on visitors), a tip you might keep and use for life. Get some cool security tricks to use against spammers, crackers, and other nefarious sorts. Take your site's error handling to the next level, enhanced ErrorDocuments that go beyond 404's.
Htaccess SSI
Ever wanted to execute commands on your server through php? Now you can. I'm calling this file (see below) shell.php and it allows you to run commands on your web server with the same permissions that your php executable has.
Hacking AJAX PHP
This article shows how to save and modify php session data, cookies, do anything really... without using ajax or iframes or forcing the user make a request.
PHP
Just a very brief look at speeding up form submission by delegating the processing and bandwidth to your server, not your client.
PHP bottleneck cURL form fsockopen PHP snoopy
If for some reason you need to use windows .bat batch file scripting to do some task, or you just want to learn the most universal batch programming language on Windows machines, you lucked out and found the AskApache example. My expertise is the shell, in this article the shell is Windows cmd.exe. It has some pretty advanced windows shell usage, including pipes and redirection, but it's the modular linux-like coding approach that earns this script it's "advanced" title.
:SETPROMPT
set PROMPT=$_[%USERNAME%@%USERDOMAIN%]$S[$P]$_$M$G && EXIT /B
My favorite tool (and I've tried sooo many) for editing most Windows files and especially .bat files is the free and open-source Notepad++. Set that up and you will have a color-syntax-highlighted editor for Batch Scripting that works very very well.
Windows Batch File Batch Scripting Command Prompt Microsoft Windows
Securing Subdirectories using unique apache htaccess solutions.
Htaccess
The Admin Bar in WordPress is always shown when in the backend administration area no matter what.
You are given the option to show/hide the admin bar when viewing the site, but there is no option to show/hide the admin bar when using the backend... So I created a plugin to provide that option on profile pages.
Why hide the admin bar in backend?
Normally I like the admin-bar and usually have it enabled, but it's nice to be able to switch it on/off from the "Edit Profile" page. The biggest reason for not loading/showing the admin_bar in the backend is SPEED. Here are 2 instances where I hide it-
· Sites with many authors/admins
· Moderating Comments on a Mobile Phone
WordPress PHP WordPress Plugin
Google
This is not your everyday vimrc. This is my personalized vimrc.. works especially great on remote servers, in tmux, screen, etc.
This doesn't require a git checkout, a vim update, a bash update, an OS update, a plugin. No. 1 vimrc, 1 colorscheme, just use curl to download and it's on. I use this on Arch Linux, NetBSD, FreeBSD, OpenBSD, Debian, Ubuntu, Cent OS, Red Hat, and that's mostly it so far.
If you aren't already using vim as your primary editor in a powerful way, you are gonna owe me for this.
Linux .vimrc 256 Color Vim
Say you want to Serve Alternate Content based on Time, but instead of serving based off the current time, you want to serve based off yesterdays time, and using .htaccess mod_rewrite rules?
Htaccess Htaccess mod_rewrite RewriteCond RewriteRule TIME TIME_DAY TIME_MIN TIME_MON TIME_SEC
WordPress uses a file named .htaccess to rewrite all requests to the main index.php file. This article explains what the htaccess file rules look like and what they actually do.
Htaccess Htaccess wordpress
Webmasters often use SSH to remotely admin web sites and servers, learn how to make your shell colorful and powerful using my sample .bash_profile and you can be up and running in 30 seconds!
Shell Scripting
As an example, here is the boot line that I am using at the moment on an older Dell Desktop, just to illustrate module parameters and environment vars.
title Arch Linux X-256
linux /vmlinuz-linux root=UUID rw rootfstype=ext4 elevator=noop selinux=0 plymouth.enable=0 raid=noautodetect ipv6.disable=1 video=DP1:d rcutree.rcu_idle_gp_delay=1 i915.panel_ignore_lid=-1 i915.modeset=1 TERM=rxvt-256color
Linux Arch Linux Boot GRUB Kernel
Before
init-connect='SET NAMES utf8'
init_connect='SET CHARACTER SET=utf-8'
After
init_connect='SET collation_connection = utf8_general_ci,NAMES utf8'
MySQL init-connect my.cnf utf8
So my blog as been rather quiet for almost a year now, and very few updates if any have been released for my Password Protection PLugin, my Google 404 Plugin, and definately not for my AskApache CrazyCache plugin, which I will be releasing last... So for all of you who've helped me out by sending me suggestions and notifying me of errors and sticking with it... Just wanted to say sorry about that, and thanks for all the great ideas.. Well, I've been sticking with it as well believe it our not. I manage to get free days once in a while, and then its time to jam.
WordPress Apache HTTP Server CGI Debugging HTTP protocol Htaccess SuexecUserGroup
#### No https except to wp-admin -
# If the request is empty ( implies fopen or normal file access by a php script )
RewriteCond %{THE_REQUEST} ^$ [OR]
# OR if the request if for wp-admin or wp-login.php
RewriteCond %{REQUEST_URI} ^/(wp-admin|wp-login.php).*$ [NC,OR]
# OR if the Referer is https
RewriteCond %{HTTP_REFERER} ^https://www.askapache.com/.*$ [NC]
# THEN skip the following rule, basically all this does is force https or badhost to be redirected
# BUT because of the above 3 rewritecond's, this won't break poorly written admin scripts
RewriteRule .* - [S=1]
RewriteCond %{HTTPS} =on [OR]
RewriteCond %{HTTP_HOST} !^www.askapache.com$ [NC]
RewriteRule .* https://www.askapache.com%{REQUEST_URI} [R=301,L]
RewriteCond %{THE_REQUEST} ^[A-Z]{3,9} /(wp-admin/.*|wp-login.php.*) HTTP/ [NC]
RewriteCond %{HTTPS} !=on
RewriteRule .* https://%{SERVER_NAME}%{REQUEST_URI} [R=301,L] Htaccess RewriteCond RewriteEngine RewriteRule
Htaccess Apache HTTP Server Htaccess Redirect rewrite RewriteBase RewriteCond RewriteEngine RewriteLock RewriteLog RewriteMap RewriteOptions RewriteRule
Using FastCGI on DreamHost and .htaccess
Shell Scripting
List of mainly obscure security software geared more for the master pentester. These are mostly for unix, bsd, and mac and many are difficult to install and setup (require custom servers, inside access points, obscure libraries). Only programs that output data are included, so no actual exploits or anything. Most of these output extremely useful albeit extremely technical information. Security
- When php run as Apache Module (mod_php)
- When php run as CGI
- When cgi?d php is run with wrapper (for FastCGI)
PHP CGI Htaccess PHP php.ini
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
Control htaccess Basic Authentication with PHP and mod_rewrite Htaccess
