Ssh, linux

Wednesday, 5 October 2011

Install Many Linux Distributions from one disk - NetbootCD

NetbootCD is a GNU/Linux live CD based on Tiny Core Linux. The live CD allows the user to download and run one of several Linux netboot installers, which can install a full GNU/Linux system with only a hard drive and Internet connection.

Several of the distributions supported by NetbootCD are prerelease distributions (such as Debian testing) or development distributions (openSUSE Factory, Fedora Rawhide, Debian sid.) Because NetbootCD downloads the latest installer, which in turn downloads the latest system components, you can install a fully up-to-date system without burning a new CD.

How to Hide data (Steganography) into MP3 file - mp3stego

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Steganography is the art and science of writing hidden messages in such a way that no one, apart from the sender and intended recipient, suspects the existence of the message, a form of security through obscurity

MP3Stego will hide information in MP3 files during the compression process. The data is first compressed, encrypted and then hidden in the MP3 bit stream. Although MP3Stego has been written with steganographic applications in mind it might be used as a copyright marking system for MP3 files (weak but still much better than the MPEG copyright flag defined by the standard). Any opponent can uncompress the bit stream and recompress it; this will delete the hidden information – actually this is the only attack we know yet – but at the expense of severe quality loss.

Generate and/or Encrypt Passwords - makepasswd

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makepasswd generates true random passwords by using the /dev/urandom feature of Linux, with the emphasis on security over pronounceability. It can also encrypt plaintext passwords given on the command line.

makepasswd Installation:
Open the terminal and type following command to install makepasswd:

sudo apt-get install makepasswd

After successful installation you can use the makepasswd using following command, here I am generating 10 diffferent passwd having character length 10

For more detail options type command makepasswd --help or check the man pages

Setting up SSH keys for Secure Password-less SSH Login

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OpenSSH is a FREE version of the SSH connectivity tools that technical users of the Internet rely on. Users of telnet, rlogin, and ftp may not realize that their password is transmitted across the Internet unencrypted, but it is. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other attacks. Additionally, OpenSSH provides secure tunneling capabilities and several authentication methods, and supports all SSH protocol versions.

The OpenSSH suite replaces rlogin and telnet with the ssh program, rcp with scp, and ftp with sftp. Also included is sshd (the server side of the package), and the other utilities like ssh-add, ssh-agent, ssh-keysign, ssh-keyscan, ssh-keygen and sftp-server.

If you manage more than one or two hosts, you likely have to type the same password too often. This can get quite annoying. SSH allows you to setup a public and private keypair. Using these keys, you can connect to any host which has the public key, from any host which has the private key.