Thursday, December 23, 2010

Control PHP Error Reporting With .htaccess

Category: — SkyHi @ Thursday, December 23, 2010
Create .htaccess file or use existing .htaccess file in your hosting site. Add below line at the top of file content.

# to stop php startup errors
php_flag display_startup_errors off
# to stop all php errors and warning
php_flag display_errors off


# php directive for setting error level
php_value error_reporting integer


# report everything except run-time notices.
php_value error_reporting 8191
# report both fatal and non-fatal compile-time warnings by the Zend Engine
php_value error_reporting 128
# report run-time notices, compile-time parse errors, run-time errors and warnings
php_value error_reporting 8
# report fatal run-time errors and unrecoverable errors
php_value error_reporting 1


===========================PHP Turn On Error Reporting =========================
To turn on Error Reporting in PHP, this is what I use. You can set this anywhere in your PHP code, but it has to be above the error or else it will not work. This is the easiest way and will work in most hosting environments:

ini_set('display_errors',1);
error_reporting(E_ALL|E_STRICT);


ini_set('display_errors',1);
error_reporting(E_ALL);


error_reporting(0);

REFERENCES
http://www.bala-krishna.com/control-php-error-reporting-with-htaccess/
http://www.bradino.com/php/error-reporting/

Wednesday, December 22, 2010

Vim indentation for C/C++ explained

Category: — SkyHi @ Wednesday, December 22, 2010
In today’s early morning post, I’m going give a short crash course about Vim settings for indentation. Every programmer knows how source code indentation important is. There is no discussion about it. Vim, my favourite text editor, provides programmer with rich indetation features set. You can customize almost all aspects of code formating. So, let’s see what kind of indentation features Vim provides and how they affect indentation.

General Indentation Settings

:set autoindent
If set, Vim automatically indents a new line to the same indentation used by previous line. In other words ViM automatically tabs a new line. smartindent and cindent are autoindent variations and changes the way indentation and formatting more precisely.
:set smartindent
Context-sensitive autoindent, great when coding, makes intendation aware of C-like syntax.
:set shiftwidth
Using this option you can define number of spaces placed on every indentation step i.e. :set shiftwidth=3 will instruct Vim to indent with 3 spaces for every TAB command.

TAB Settings

:set expandtab
Use this option if you want every TAB to be expanded to spaces.
:set smarttab
If this option is set, then TAB command shifts line to right and BACKSPACE shifts line to left, both inserting number of blanks as defined in shiftwidth. If smarttab is not set, then TAB inserts blanks according to tabstop.
:set softtabstop
This one tells Vim to interpret TAB as an indent command instead of insert-a-TAB command.
:set tabstop
Simply, it instructs Vim how many space characters Vim counts for every TAB command. According to Vim manual it’s recommended to leave default tabstop=8, what means every TAB is displayed with 8 space characters, and adjust only softtabstop and shiftwidth.

C-style Indent

:set cindent
This sets autoindent to even more smart and strict mode for C and C++ source code.
:set cinoptions
Simply, it sets cindent configuration options.

Help

To learn how to use Vim commands and how to set indentation settings refer to online VimDoc or run open help :h where option is one of Vim command. I also recommend to take a look at the Vim website with documentation and huge database of tips.

Online Resources

Vi and Vim in Linux Productivity Magazine, Volume 1 Issue 5
Introduction to Programming in C/C++ with Vim by Kmj
VIM (Vi IMproved)
The Vi/Ex Editor by Walter Alan Zintz
Vi for programmers, part 1 and part 2

REFERENCES
http://mateusz.loskot.net/2005/11/06/vim-indentation-for-c-cpp-explained/

Ultimate List of Open Source Software

Category: , — SkyHi @ Wednesday, December 22, 2010
Ultimate list of open source software:
 

 REFERENCES
 http://itmanagement.earthweb.com/osrc/article.php/3918051/Utlimate-List-of-Open-Source-Software.htm

10 Bash Tips for Working Faster With the Shell (Part 1 of 2)

Category: — SkyHi @ Wednesday, December 22, 2010
This command is used to bring back and automatically execute the last command in history. It is the same as pressing C^P followed by Enter). Here’s an example:


Using !text
Replacing ‘text’ with any command will call the last command in the history which starts with ‘text’. Example:
As you can see after issuing the first ls command we printed the working directory, then we called back the last ls command with !ls.

Using !n
This will bring up the nth command in history. This will vary depending on your history. Here’s an example:

Using !?text?
This will execute the most recent command that contains the word ‘text’. Example:
The most recent command containing the text ‘xjf’ was executed. This trick should be applied carefully though, especially for sensitive commands like rm.

Using !! in combination with another command
!! can also be used in combination with some other command, because the shell expands it first and then it executes the current command. For example, this can be very useful in combination with sudo, since sometimes we forget to use administrative privileges for commands that need it. For example:

Changing the color of the Bash prompt
There are many ways of customizing your Bash prompt, and I will list here only a few pre-defined sets.
To make the user’s prompt green, put this inside your ~/.bashrc file, where ~ is your home directory:

Now run source ~/.bashrc or . ~/.bashrc to read the settings again. Here’s how your prompt should look like:


Here’s another example, which will make your prompt look really fancy:

And this is how it will look like:

A pretty good tutorial on this can be found here (Bash Prompts How-To) and several prompt schemes on the Arch Wiki, here. The Bash Reference manual section on this include some useful information too.

Catch the exit status of a command with $?
If a command is successful, its exit status will be 0, otherwise it will be different from 0. This can be useful in scripts.

Using reversed search: Ctrl-R
Ctrl-R will prompt you to enter a pattern for a command, and will search the history in reversed order for any the first command that contains the pattern and execute it. Example
In the above example we issued the ls -lh command, the pressed Ctrl-R and typed in the letter L. The command was brought up and then executed with Enter.

Using cd – to go to the previous working directory
This command will have the same effect as cd $OLDPWD, where $OLDPWD is a variable that holds the previous working directory.

Using grep -e -pattern to show the lines that start with a – sign
This will be useful if piped to commands like man, for example:
This will query the manual page for gcc and will only print lines that contain the text -ansi.


REFERENCES
http://www.tuxarena.com/?p=257

Tuesday, December 21, 2010

Increase the import “file size” in phpMyadmin

Category: — SkyHi @ Tuesday, December 21, 2010
The first and only things to check (or ask your host provider to check) are the values of upload_max_filesize (Default 2M)

memory_limit (Default 16M)

and post_max_size (Default 8M)

in the php.ini

increase all as per your need

Then you have to restart the web server


================================================================

Uploading large(big) files in PHP using .htaccess

I’ve seen that many of my friends are struggling with the uploads of the bigger or larger files in PHP. After looking at their struggle, i’m here to solve the problem of uploading larger or bigger files in PHP.
Most of the web servers are configured such a way that a user can only upload the maximum file size of 2MB. So there might be the problem for the people who wants to upload the .pdf file of size around 15MB. But, you can increse the maximum upload file size limit by using .htaccess file.

Here is a small tips for you which you can use to upload such a large file using file field of the form and move_uploaded_file() function in PHP.
1) Create a .htaccess file in the root folder of web server.
2) Put the following code in side the .htaccess file and save it.
php_value upload_max_filesize 20M
php_value post_max_size 20M
php_value max_execution_time 200
php_value max_input_time 200
Now you can upload the file-size up-to 20MB in a simple way using file field in your html form and move_uploaded_file() function available in PHP. In the above .htaccess file, uploading capability is increased by the four parameter first one is maximum file size for uploading, second one is maximum size of the post data , third one is maximum time in seconds a script is allowed to run before it is terminated by the parser and last one is maximum time in seconds a script is allowed to parse input data such as like file uploads, POST and GET data.
You can change the above parameter to upload the bigger file size than 20MB.

 


REFERENCES
http://junal.wordpress.com/2007/10/03/increase-the-import-file-size-in-phpmyadmin/
http://roshanbh.com.np/2008/01/uploading-larger-files-in-php.html

Openvpn Amazon EC2 Firesheep Wireless

Category: , , , — SkyHi @ Tuesday, December 21, 2010
If your laptop ever connects to a network behind enemy lines (e.g. hhonors, attwifi, panera), this post is for you. The step-by-step directions below allow you to stand up a portable, cloud-based private VPN that you can use from anywhere – for around $0.50 a month. Once you get everything setup, you can feel good connecting to a hotspot and laugh at the guy running FireSheep.

Speaking of Firesheep, I’ve actually had some people close to me (including my wife) ask how they can prevent these types of attacks from happening. There are some nice “off-the-shelf” solutions like HTTPS Everywhere and BlackSheep but as a security professional I wanted to give a recommendation that would provide broader coverage than these solutions.

Enter Amazon’s recently introduced Free Tier for EC2. I’ll save my thoughts and comments on “The Cloud” and security for a later date (and after a couple of beers), but for the purposes of this solution, it works great to help you increase your security while using open wireless networks. Quite simply, the solution I came up with was to create an EC2 instance with Ubuntu 10.04 LTS server and setup OpenVPN and SideStep. This allows me to route all of my traffic over an SSL or SSH VPN to my EC2 instance and then out to the Internet.

To graphically represent what this solution offers, below is a picture of your laptop while surfing on an Open Wi-Fi network such as those at Starbucks.
 
The second image is the guy running Firesheep at Starbucks.
The last image depicts your laptop running OpenVPN or SideStep at Starbucks.
 
 
Enough with the ‘Behind Enemy Lines’ comparisons…I swear. I installed other services on my EC2 instance, like Privoxy and iodine (see my post on tunneling traffic via iodine), but for the purpose of this post, I will limit the scope to creating an EC2 instance, installing and configuring OpenVPN, and installing and configuring SideStep.

A couple of notes before we get started. While the instructions that follow utilize Amazon’s Free Tier, this setup will cost you roughly $.50 per month. There are ways to shrink your EC2 ami to fit within the Free Tier’s EBS limit of 10GB, but I will pay around $.50 a month to have this service available to me (the Ubuntu AMI we will use utilizes 15GB of EBS).

Also, thanks to Chetan Surpur, TaoSecurity, Alestic, and Ivan Kristianto.

So let’s get started…

1. If you haven’t already, head over to Amazon EC2 and create an Amazon EC2 account.

2. Once you have created an account, visit the AWS Management Console and click on the ‘Key Pairs’ link on the left side of the screen. Here you will create a Key Pair that will allow you to login to your EC2 instances. Click on the ‘Create Key Pair’ button and name the Key Pair something unique. I chose ‘JustinsAllEC2Key’. Save the file in your ~/Download folders and move it to your ~/.ssh/ folder by issuing the following commands:

Your Mac
jmorehouse@Old-Trafford:~$ cd Downloads
jmorehouse@Old-Trafford:Downloads$ mv JustinsAllEC2Key.pem ~/.ssh/
jmorehouse@Old-Trafford:Downloads$ chmod 400 ~/.ssh/JustinsAllEC2Key.pem

3. Now that you have a key pair, it is time to create and launch an instance. Click on the ‘AMIs’ link on the left side. Then select All Images from the ‘Viewing’ drop-down (it takes a minute to load all of the available instances), and search for ‘ami-4a0df923‘. This is an EBS instance of Ubuntu 10.04 LTS Server 64-bit from Alestic. EBS allows for persistent storage, so that your setting will remain even when you power-cycle your instance.

4. Select the AMI and then click the ‘Launch’ button at the top. You will be prompted with a number of options, and I recommend using the following:
  • Number of Instances: 1
  • Availability Zone: No Preference
  • Instance Type: Micro
  • Launch Instances
  • Click ‘Continue’

  • Kernel ID: Default
  • RAM Disk ID: Default
  • No Monitoring
  • No User Data
  • Click ‘Continue’

  • Key = ‘Name’
  • Value = ‘Free Tier EC2 Ubuntu 10.04 Instance’
  • Click ‘Continue’

  • Choose from your existing Key Pairs – ‘JustinsAllEC2Key’ -> This is the key you previously created in Step 2 and moved to your ~/.ssh/ folder.
  • Create a new Security Group – ‘InternetAccessible’ -> This akin to a firewall ruleset group. I created a new once called ‘InternetAccessible’, but you can just as simply use and edit the ‘Default’ group.
  • Describe your security group – ‘Services allowed from the Internet’
  • Select ‘SSH’ from the drop-down ‘Applications’ menu -> I left ‘All Internet’ as we want to access this instance from wherever we are on the Internet.
  • Click ‘Add Rule’
  • Select ‘HTTPS’ from the drop-down ‘Applications’ menu -> This will give us access to our OpenVPN server. I also left this open to ‘All Internet’ for the same reason we configured SSH this way.
  • Click ‘Add Rule’
  • Click ‘Continue’

5. You are then be presented with a confirmation page where you should confirm your setting and make any necessary changes. If everything looks good, go ahead and launch your instance.

6. Your instance is now launching. Click on the ‘View your instances on the Instances page’ link to access information about your instance.

7. Now we will assign a static IP address to your instance as Amazon makes this feature available for free (what IPv4 shortage?). Click on the ‘Elastic IPs’ link on the left side. Then click on the ‘Allocate New Address’ button in the center of the page. Click the ‘Yes, Allocate’ button, and then click the checkbox infront of the newly added IP address. We want to associate this IP with your newly created instance. You can do this by now clicking on the ‘Associate’ button at the top. Select the ‘Instance ID’ for the instance you just created (there should be only one Instance ID in the drop-down) and click ‘Associate’. Copy the IP address somewhere handy as we will need it in a couple of minutes.

8. Once you have done this, it’s time to login to your EC2 instance! You can perform this from Terminal using the following:

Your Mac
jmorehouse@Old-Trafford:Downloads$ cd ~
jmorehouse@Old-Trafford:~$ ssh -i ~/.ssh/.pem ubuntu@IPAddress

9. Type ‘yes’ to accept the RSA key fingerprint and you should see something akin to the following:
Linux ec2 2.6.32-309-ec2 #18-Ubuntu SMP Mon Oct 18 21:00:50 UTC 2010 x86_64 GNU/Linux
Ubuntu 10.04.1 LTS
Welcome to Ubuntu!
* Documentation: https://help.ubuntu.com/
System information as of Fri Dec 3 00:40:20 UTC 2010
System load: 0.0 Processes: 60
Usage of /: 6.2% of 14.76GB Users logged in: 1
Memory usage: 6% IP address for eth0: 10.XX.XX.XX
Swap usage: 0% IP address for tun0: 10.X.XX.X
Graph this data and manage this system at https://landscape.canonical.com/
———————————————————————
At the moment, only the core of the system is installed. To tune the
system to your needs, you can choose to install one or more
predefined collections of software by running the following
command:
sudo tasksel –section server
———————————————————————
14 packages can be updated.
4 updates are security updates.
Last login: Thu Dec 2 23:22:38 2010 from pool-XX-XX-XX-X.domain.net
10. At this point you want to perform some hardening and maintenance on the box.

Update passwords
EC2 Instance
ubuntu@ec2:~$ sudo su -
ubuntu@ec2:~$ passwd ubuntu (Enter in a new password for the ‘ubuntu’ account. This is the default account on your EC2 instance. I recommend storing these passwords in KeePassX)
ubuntu@ec2:~$ passwd (Enter in a new password for the ‘root’ account. This account should be need no explination.)

Update packages
EC2 Instance
ubuntu@ec2:~$ exit
ubuntu@ec2:~$ sudo apt-get update (This updates the list of known packages.)
ubuntu@ec2:~$ sudo apt-get upgrade -y (This upgrades the installed packages to their latest version.)

If you are prompted for grub-pc config update, just hit enter. Also select ‘Yes’ at the next Grub message window.

Time Zone
EC2 Instance
ubuntu@ec2:~$ sudo dpkg-reconfigure tzdata

Follow the instructions to setup the proper timezone information for your EC2 instance.

ubuntu@ec2:~$ sudo reboot now (This will reboot the sytem. Wait about 2 minutes before you try and reconnect to the EC2 instance via Terminal using the above ssh command.)

11. At this point I setup a host record for my EC2 instance so that I could use DNS to access it. I also configured the hostname on the system to match the DNS record. This is an optional step, and if you aren’t sure what I am talking about or aren’t sure how to do it, don’t worry about it.

12. Now that we have our EC2 instance configured and ready to go, it is time to install and configure OpenVPN. To install OpenVPN on your EC2 instance, simply type the following from within your SSH session:

EC2 Instance
ubuntu@ec2:~$ sudo apt-get -y install openvpn libssl-dev openssl

13. Now we need to create the certificates to use with OpenVPN. First let’s copy the easy-rsa tool to the OpenVPN folder.

EC2 Instance
ubuntu@ec2:~$ cd /etc/openvpn/
ubuntu@ec2:/etc/openvpn$ sudo mkdir easy-rsa
ubuntu@ec2:/etc/openvpn$ sudo cp -r /usr/share/doc/openvpn/examples/easy-rsa/2.0/* /etc/openvpn/easy-rsa/
ubuntu@ec2:/etc/openvpn$ sudo chown -R $USER /etc/openvpn/easy-rsa/
ubuntu@ec2:/etc/openvpn$ cd /etc/openvpn/easy-rsa/

14. We now need to edit the ‘vars’ file to provide some information for our SSL certificates. You will need to know how to use the ‘vi’ text editor. If you don’t know how to use it, I recommend this tutorial.

EC2 Instance
ubuntu@ec2:/etc/openvpn/easy-rsa$ sudo vi vars

Change export ‘KEY_SIZE=1024′ to ‘export KEY_SIZE=2048′
Change export KEY_COUNTRY=”US” to your country.
Change export KEY_PROVINCE=”CA” to your state. I.e. ‘KEY_PROVINCE=”FL”‘
Change export KEY_CITY=”SanFrancisco” to your city. I.e. ‘KEY_CITY=”Tampa”‘
Change export KEY_ORG=”Fort-Funston” to your organization or something else. I did my family (‘KEY_ORG:”Morehouse-Family”‘)
Change export KEY_EMAIL=”me@myhost.mydomain” to your email address.

Save the file by hitting the ‘ESC’ key and then typing ‘:wq’ and press enter.

ubuntu@ec2:/etc/openvpn/easy-rsa$ source vars
ubuntu@ec2:/etc/openvpn/easy-rsa$ ./clean-all
ubuntu@ec2:/etc/openvpn/easy-rsa$ source vars
ubuntu@ec2:/etc/openvpn/easy-rsa$ ./build-ca

You should be prompted for the following. You can hit ‘enter’ to keep the default value you already setup by editing the ‘vars’ file.

Country Name (2 letter code) [US]:
State or Province Name (full name) [FL]:
Locality Name (eg, city) [Tampa]:
Organization Name (eg, company) [Morehouse-Family]:
Organizational Unit Name (eg, section) []:Personal
Common Name (eg, your name or your server’s hostname) [justin.domain.org]: -> Enter your hostname here if you created a DNS record. Otherwise enter your EC2′s Elastic IP address from Step 7.
Name []:Justin Morehouse
Email Address [justin@mydomain.com]:

Now execute the following commands:

ubuntu@ec2:/etc/openvpn/easy-rsa$ ./build-dh (This takes some time. Like 2 minutes.)
ubuntu@ec2:/etc/openvpn/easy-rsa$ source vars
ubuntu@ec2:/etc/openvpn/easy-rsa$ ./pkitool --server server
ubuntu@ec2:/etc/openvpn/easy-rsa$ cd keys
ubuntu@ec2:/etc/openvpn/easy-rsa/keys$ openvpn --genkey --secret ta.key
ubuntu@ec2:/etc/openvpn/easy-rsa/keys$ sudo cp server.crt server.key ca.crt dh2048.pem ta.key /etc/openvpn/

15. Now we have created the CA and Server certificates. Now we need to create keys for our users. For the purpose of this blog, we will create one key for one user. You can repeat this step for each additional user you wish to allow to access your OpenVPN server.

EC2 Instance
ubuntu@ec2:/etc/openvpn/easy-rsa/keys$ cd..
ubuntu@ec2:/etc/openvpn/easy-rsa$ source vars
ubuntu@ec2:/etc/openvpn/easy-rsa$ ./pkitool (I typed ‘./pkitool justin’)
ubuntu@ec2:/etc/openvpn/easy-rsa$ cd ..

16. Now we need to create an archive to download all of the necessary files from the server to the system you want to configure to use OpenVPN (Your laptop). I recommend using Cyberduck to access the .tar file we create. Remember to use your EC2 key to login with Cyberduck. It is the key we created in Step 2 and stored in your ~/.ssh/ folder (JustinsAllEC2Key.pem). Remember, the keys.tar file will be located in the /etc/openvpn/ directory. Download the keys.tar file to your Downloads directory.

EC2 Instance
ubuntu@ec2:/etc/openvpn$ sudo tar czf keys.tgz ca.crt ta.key easy-rsa/keys/yourname.crt easy-rsa/keys/yourname.key

17. Now it’s time to configure your OpenVPN server. You can most likely use the pre-configured template I posted online. It uses the IP address scheme of 10.8.80.0/24 for VPN clients, so unless you are using that network somewhere else, you don’t need to change a thing in the configuration. If you do need to edit the network, you can download the server.conf file here or issue the commands below and use vi to edit it as you would like. Use the commands below to download the server.conf file to the /etc/openvpn folder on your EC2 instance.

EC2 Instance
ubuntu@ec2:/etc/openvpn$ sudo wget http://www.stratumsecurity.com/sites/default/files/server.conf

18. Now we have to setup ip forwarding on your EC2 instance. We’ll use sudo to perform these commands.

EC2 Instance
ubuntu@ec2:~$ sudo su -
root@ec2:~$ modprobe iptable_nat
root@ec2:~$ echo 1 > /proc/sys/net/ipv4/ip_forward
root@ec2:~$ iptables -t nat -A POSTROUTING -s 10.8.80.0/24 -o eth0 -j MASQUERADE
root@ec2:~$ iptables-save > /etc/iptables.conf
root@ec2:~$ echo '#!/bin/sh' > /etc/network/if-up.d/iptables
root@ec2:~$ echo "iptables-restore < /etc/iptables.conf" >> /etc/network/if-up.d/iptables
root@ec2:~$ chmod +x /etc/network/if-up.d/iptables
root@ec2:~$ echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
root@ec2:~$ reboot now

19. Back on your Mac, download and install Tunnelblick. It is is a free, open source Graphic User Interface (GUI) for OpenVPN on Mac OS X. You can download the latest stable version from here.

20. Once you have installed Tunnel blick, go do your ‘Downloads’ folder and extract your keys.tar files. Copy the ca.crt, ta.key, .crt, and files from the extracted .tar file to the Tunnelblick directory located at ‘~/Library/Application\ Support/Tunnelblick/Configurations/‘. (.crt and will be in the ‘easy-rsa/keys’ folder. Make sure all of the extracted files are in the ‘~/Library/Application\ Support/Tunnelblick/Configurations/‘ folder!)

21. You will now need to edit the client template that I have posted here. Download the file to ‘~/Library/Application\ Support/Tunnelblick/Configurations/‘ and edit the following three items:
  • Line 42: Change ‘’ to your EC2 instance’s IP address, from Step 7, or the DNS name you gave it.
  • Lines 89 & 90: Change cert .crt & key .key to the names of the .crt and .key files you extracted from the keys.tar file. This the client certificate you created for yourself in Step 15.
22. Once this is done, open up a web browser and go to IP Chicken. Obesrve your current source IP address. Then open Tunnelblick and from the menu bar at the top, select Connect ‘ec2′. Reload your browser and notice that you now have a source IP address of your EC2 instance! Congratulations on getting OpenVPN on an EC2 instance setup. Now let’s setup SideStep.

23. While Tunnelblick allows you to create an on-demand SSL tunnel to proxy all of your network traffic through your EC2 instance (for both wired and wireless) networks, SideStep takes the guess work out of when to use a proxy to secure your network when you are on an open wireless network (it currently only works on wireless networks, but Chetan is going add the capability to use it on an wired network as well). First download and install SideStep.

24. SideStep uses passwords or keys to create an on-demand SSH tunnel that proxies your traffic. As our EC2 instance doesn’t allow for password logins via SSH, we need to create a new keypair to use with SideStep. Using Terminal on your Mac, issue the following commands:

Your Mac
jmorehouse@Old-Trafford:~$ cd ~
jmorehouse@Old-Trafford:~$ ssh-keygen -t rsa -f ~/.ssh/id_ec2

Enter in a passphrase twice, and store it some place safe (KeePassX) because you will need it later.

jmorehouse@Old-Trafford:~$ scp -i .ssh/JustinsAllEC2Key.pem .ssh/id_ec2.pub ubuntu@IP:~/.ssh/ (Key created in Step 2 and IP address from Step 7.)

25. Still within Terminal, log back into your EC2 instance and append the public key to your authorized_keys file.

Your Mac
jmorehouse@Old-Trafford:~$ cd ~
jmorehouse@Old-Trafford:~$ ssh -i ~/.ssh/.pem ubuntu@IPAddress (Key created in Step 2 and IP address from Step 7.)

EC2 Instance
ubuntu@ec2:~$ cd .ssh/
ubuntu@ec2:~/.ssh/$ cat >> authorized_keys id_ec2.pub
ubuntu@ec2:~/.ssh/$ chmod 640 authorized_keys
ubuntu@ec2:~/.ssh/$ exit

26. Now we need OSX to prompt us for the passphrase for the id_ec2 key, so from Terminal, enter the following:

Your Mac
jmorehouse@Old-Trafford:~$ cd ~
jmorehouse@Old-Trafford:~$ ssh -i .ssh/id_ec2 ubuntu@IP

You should be prompted for a password. Check the save the password to your Key Chain and hit ok. You should now have an SSH session to your EC2 box using your new key. You can go ahead and exit from your SSH session and close out all of your Terminal sessions and quit the Terminal application.

27. Now fire up SideStep and click the ‘Next’ button. Under ‘I already have one’ enter ‘ubuntu’ as the Username, your IP address from Step 7 as the hostname, and press ‘Test Connection to Server.’ You should receive a ‘Connection to server succeeded!’ message. Now click the ‘Next’ button. Read the notes and check the box that reads ‘Run SideStep on login.’ Click ‘Finish.’

28. SideStep is now on the menu bar next to Tunnelblick. I added Tunnelblick to my login items so that it is launched when I boot. Understand the differences between these two tools (Tunnelblick and SideStep) and when to use each.

Congratulations! If you made it this far, pat yourself on the back. This was a long tutorial, but it should work if you followed each step. If you have any problems, hit me up on Twitter (@Mascasa).

Enjoy surfing open wireless networks or hostile wired network securely!
 

Monday, December 20, 2010

Windows wget

Category: , — SkyHi @ Monday, December 20, 2010

wget is a great command line utility that is natively available in Linux and can be downloaded for Windows (see also GNU WGet for Windows (Windows 7, Vista, XP, etc.)). wget can be used for many download situations including large files, recursive downloads, non-interactive downloads, multiple file downloads, etc.



Note: options ARE case sensitive.



1. Download a single file with wget using no options.

wget http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz
While downloading, wget will display a progress bar with the following information:

  • % of download completion
  • Download progress in bytes
  • Current download speed
  • Estimated time remaining
Download in progress



















Completed download





















2. Download a file saving with a different name using wget -O

wget http://www.vim.org/scripts/download_script.php?src_id=7701
Even though the downloaded file is in zip format, it will be saved with the name download_script.php?src_id=7701 without the -O switch.



To modify this behavior specify the output file name using the -O option.

wget -O taglist.zip http://www.vim.org/scripts/download_script.php?src_id=7701
3. Specify download speed / download rate Using wget –limit-rate



While executing the wget, by default it will try to use all possible bandwidth. You can limit the download speed using the –limit-rate switch.

wget --limit-rate=200k http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz
4. Restart a download which stopped in the middle using wget -c.

wget -c http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz
5. Download in the background with wget -b

wget -b http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz










The download will begin and give back the shell prompt to you. You can always check the status of the download using tail -f  (Linux only) .

tail -f wget-log
6. Mask user agent and display wget like browser using wget –user-agent



Some websites can disallow you to download its page by identifying that the user agent is not a browser. So you can mask the user agent by using –user-agent options and show wget like a browser.

wget --user-agent="Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.3) Gecko/2008092416 Firefox/3.0.3" http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz
7. Test URL using wget –spider.  This will test that the file exists, but not perform the download.

wget --spider http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz
















8. Increase total number of retry attempts using wget –tries.

wget --tries=75 http://ftp.gnu.org/gnu/wget/wget-latest.tar.gz
9. Download multiple files / URLs using wget -i



First, store all the download files or URLs in a text file:

URL1

URL2

URL3

URL4



Next, give the download-file-list.txt as argument to wget using -i option.

wget -i download-file-list.txt
10. Download a full website using wget –mirror

wget --mirror -p --convert-links -P ./LOCAL-DIR WEBSITE-URL
  • –mirror: enable mirroring
  • -p: download all files that are necessary to properly display a given HTML page
  • –convert-link: after the download, convert the links in document for local viewing
  • -P ./LOCAL-DIR: save all the files and directories to the specified directory
11. Skip certain file types while downloading using wget –reject.  In order to download all content except .gif images use the following.

wget --reject=gif WEBSITE-TO-BE-DOWNLOADED
12. Log messages to a log file instead of stderr using wget -o.  To redirect output to a log file instead of the terminal.

wget -o download.log DOWNLOAD-URL
13. Quit downloading when certain size is exceeded using wget -Q.

wget -Q5m -i FILE-WHICH-HAS-URLS
14. Download only certain file types using wget -r -A



You can use this for the following situations

  • Download all images from a website
  • Download all videos from a website
  • Download all PDF files from a website
wget -r -A.pdf http://url-to-webpage-with-pdfs/
15. You can use wget to perform FTP downloads.

wget ftp-url
FTP download using wget with username and password authentication.

wget --ftp-user=USERNAME --ftp-password=PASSWORD DOWNLOAD-URL
Note: username and password can be used for HTTP and HTTPS downloads as well using --http-user=USER, --http-password=PASS respectively.

REFERENCES
http://www.powercram.com/2010/01/how-to-use-wget-includes-several.html
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