First create some empty files: Note that changing permissions the wrong way on the wrong files can quickly mess up your system a great deal! Please be careful when using sudo! Please note the warning in the chmod with sudo section and the Warning with Recursive chmod section.
This is particularly important if the computer is visible on the internet. If you don't think it's important, try logging the login attempts you get for the next week.
My computer - a perfectly ordinary desktop PC - had over 4, attempts to guess my password and almost 2, break-in attempts in the last week alone. With public key authentication, the authenticating entity has a public key and a private key.
Each key is a large number with special mathematical properties.
The private key is kept on the computer you log in from, while the public key is stored on the. When you log in to a computer, the SSH server uses the public key to "lock" messages in a way that can only be "unlocked" by your private key - this means that even the most resourceful attacker can't snoop on, or interfere with, your session.
As an extra security measure, most SSH programs store the private key in a passphrase-protected format, so that if your computer is stolen or broken in to, you should have enough time to disable your old public key before they break the passphrase and start using your key.
Wikipedia has a more detailed explanation of how keys work. Public key authentication is a much better solution than passwords for most people. In fact, if you don't mind leaving a private key unprotected on your hard disk, you can even use keys to do secure automatic log-ins - as part of a network backup, for example.
Different SSH programs generate public keys in different ways, but they all generate public keys in a similar format: Key-based authentication has several advantages over password authentication, for example the key values are significantly more difficult to brute-force, or guess than plain passwords, provided an ample key length.
Other authentication methods are only used in very specific situations. Both of these were considered state-of-the-art algorithms when SSH was invented, but DSA has come to be seen as less secure in recent years.
Key-based authentication uses two keys, one "public" key that anyone is allowed to see, and another "private" key that only the owner is allowed to see. To securely communicate using key-based authentication, one needs to create a key pair, securely store the private key on the computer one wants to log in from, and store the public key on the computer one wants to log in to.
Using key based logins with ssh is generally considered more secure than using plain password logins.
This should be done on the client. To create your public and private SSH keys on the command-line: This passphrase will protect your private key while it's stored on the hard drive: Enter passphrase empty for no passphrase: Enter same passphrase again: Your public key is now available as.
You now have a set of keys. Now it's time to make your systems allow you to login with them Choosing a good passphrase You need to change all your locks if your RSA key is stolen. Otherwise the thief could impersonate you wherever you authenticate with that key.
An SSH key passphrase is a secondary form of security that gives you a little time when your keys are stolen. If your RSA key has a strong passphraseit might take your attacker a few hours to guess by brute force.
That extra time should be enough to log in to any computers you have an account on, delete your old key from the. Your SSH key passphrase is only used to protect your private key from thieves. It's never transmitted over the Internet, and the strength of your key has nothing to do with the strength of your passphrase.
The decision to protect your key with a passphrase involves convenience x security. Note that if you protect your key with a passphrase, then when you type the passphrase to unlock it, your local computer will generally leave the key unlocked for a time. So if you use the key multiple times without logging out of your local account in the meantime, you will probably only have to type the passphrase once.What OS is the server running on?
If it's Linux, you should make sure that the apache user (the exact user name will depend on your setup - often httpd or www-data under Linux) has .
Two Ubuntu servers, each with a non-root user with sudo privileges and private networking enabled. For assistance setting up a user with these privileges, follow our Initial Server Setup with Ubuntu guide.
For help setting up private networking, see . The objective is to configure basic Samba server to share user home directories as well as provide read-write anonymous access to selected directory. There are myriads of possible other Samba configurations, however the aim of this guide is to get you started with some basics which can be later.
Sep 29, · TL;DR. A much shorter guide is available in the Ubuntu Server Guide If you need more info, read below.. Introduction. NFS (Network File System) allows you to 'share' a directory located on one networked computer with other computers/devices on that network.
Access USB drive on Ubuntu server. Ask Question. up vote 2 down vote favorite. 3. I'm currently using a Ubuntu server with command line access only. vetconnexx.com files are on my Windows and I want to transfer them. After that, you have to mount it to have possibility to read/write, for example.
In a previous article, we showed you how to create a shared directory in vetconnexx.com, we will describe how to give read/write access to a user on a specific directory in Linux. There are two possible methods of doing this: the first is using ACLs (Access Control Lists) and the second is creating user groups to manage file permissions, as explained below.