Category: Server

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How to mine Bitcoin in Ubuntu using OpenCL and Bitcoinminer.py

Bitcoin is a form of decentralize digital currency, so unlike other digital currency services (like e-gold), bitcoin is not susceptible to be frozen, seized or invalidated. Bitcoin can be transfered transfered directly from person to person directly without intermediaries.

Bitcoin are generated over the internet by application called bitcoin miners using a set of algorithm to ensure that the number of generated bitcoin is within predictable and limited range. Though with the numbers of bitcoin in circulation today means that it would require significant processing power to generate bitcoins, it doesn’t stop anybody who are willing to try and mine them.

For a brief introduction to Bitcoin, please watch :

Bitcoin Miner on Ubuntu ?
Enter OpenCL and Bitcoinminer.py which allows bitcoin to be mined using a much more efficient GPU power (certain models of Nvidia and ATI graphic cards only, with appropriate drivers).

Step 1: To install the miner, you need to “install python-pyopencl subversion.

Step 2: Then you need to use subversion to obtain python-jsonrpc, by running:

svn checkout http://svn.json-rpc.org/trunk/python-jsonrpc
cd python-jsonrpc/
sudo python setup.py install

Step 3: Then you need to generate bitcoin.conf file:

cd ..
mkdir .bitcoin
echo "rpcuser=username" > .bitcoin/bitcoin.conf
echo "rpcpassword=password" >> .bitcoin/bitcoin.conf

Step 4: After that, download BitcoinMiner files

wget --no-check-certificate https://github.com/m0mchil/poclbm/raw/master/BitcoinMiner.cl
wget --no-check-certificate https://github.com/m0mchil/poclbm/raw/master/BitcoinMiner.py
wget --no-check-certificate https://github.com/m0mchil/poclbm/raw/master/poclbm.py

Step 5: Download bitcoin server for linux

wget http://iweb.dl.sourceforge.net/project/bitcoin/Bitcoin/bitcoin-0.3.19/bitcoin-0.3.19-linux.tar.gz
tar xvf bitcoin-0.3.19-linux.tar.gz
~/bitcoin-0.3.19/bin/64/bitcoin -server&

Step 6: Then finally, running the miner

python poclbm.py -d 0 --user username --pass password

The parameter -d 0 denotes that the miner will use GPU #1 for its bitcoin mining generation, increment it to -d 1 for GPU #2 and so forth. Change the “password” and “username” parameter from Step 3 and Step 6 appropriately to keep people from reaping the fruits (read: steal bitcoins) of your mining operation.

For more information about mining bitcoins and about Bitcoin in general, please visit : WeUseCoins website

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Setup Free Web Proxy Service with Glype (PHP Script)

Glype is a web-based proxy script written in PHP which allows user to browse the internet anonymously using a web-based user-interface. Website operator can easily setup web-proxy without the need to go through complicated installation procedures.

Glype Proxy Service

Among the feature of Glype Proxy Script are:

  • No Installation – Just upload and done!
  • Javascript support – Allows website to keep their javascript functionality
  • Blacklist by IP – Admin can easily block users by IP address range
  • Virtual browser – allow user to change user-agent and
  • Server-side caching – Reduces bandwidth and server loads for frequently accessed website

Download Glype from its official website

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Iptables rule to safeguard SSH server from crackers

Secured Shell or SSH is a service to enable users to access remote system securely. However, SSH servers depending on password-based authentication might be vulnerable to dictionary-based (or brute-force) attacks by crackers.

Luckily iptables can be used with ‘–limit-burst‘ and ‘–limit’ option to reduce the number of attempts and connection that a cracking tool can make in a period of time.

For example, in order to limit an IP address to making only 5 connections per minute in burst of 2 connections, you can use this iptables rules:

iptables -A INPUT -p tcp --dport ssh -m limit --limit 5/minute --limit-burst 2 -j ACCEPT

This will result in the iptables will only allow up to 5 connections per minute with 2 maximum initial number of connections, which will make any brute-force or dictionary-based attack uneconomical/unfeasible for the server.

Read more about iptables –limit and –limit-burst in Linux Iptables Limit the number of incoming tcp connection / syn-flood attacks

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Restricting normal user account access on Ubuntu Server

Here’s a tip to restrict normal user account access so that common users may not be able to explore other directories beyond his/her own /home directory.

  • First you need to chmod all /home dir to 0700
  • Then, you need to set the default umask to 077, to do that, you ned to edit /etc/profile, and replace “umask 022” with “umask 077“.
  • Optionally, you can also update PAM configuration in /etc/pamd.d/common-session so that the line reads “pam_umask.so umask=077 usergroups“

The tips has been adapted from – superuser.com