Generate Ssh Key Putty Linux

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  1. This article provides steps for generating RSA keys by using PuTTYgen on Windows for secure SSH authentication with OpenSSH. Generate keys. In Windows, use PuTTYgen to generate your public and private keys. If needed, download PuTTYgen from the PuTTY download page. (PuTTYgen might have been installed previously with PuTTY or WinSCP.).
  2. To create and use SSH keys on Windows, you need to download and install both PuTTY, the utility used to connect to remote servers through SSH, and PuTTYgen, a utility used to create SSH keys. On the PuTTY website, download the.msi file in the Package files section at the top of the page, under MSI (‘Windows Installer’). Next, install it on your local computer by double clicking it and using the.
  3. Generate a private and public key pair Open PuTTYgen.exe, press Generate button, move mouse. Once the keys are generated, type your key passphrase (choose a 'hard to guess' one).

PuTTYgen is a key generator tool for creating pairs of public and private SSH keys. It is one of the components of the open-source networking client PuTTY. Although originally written for Microsoft Windows operating system, it is now officially available for multiple operating systems including macOS, Linux. PuTTYgen.exe is the graphical tool on Windows OS. While on the other side, Linux OS has the only command-line version could be accessible using SSH commands.

  • 1 Download PuTTYgen
    • 1.1 Download PuTTYgen on Windows
    • 1.2 Download PuTTYgen for Mac
    • 1.3 Download PuTTYgen for Ubuntu/Linux
      • 1.3.3 Types of Keys Supported on PuTTYgen

May 05, 2019  Creating SSH keys with PuTTYgen. To generate an SSH key pair on Windows using PuTTYgen perform the following steps: Start the PuTTYgen tool, by double-clicking on its.exe file or going to the Windows Start menu → PuTTY (64-bit) → PuTTYgen. For “Type of key to generate”. Generate your SSH Key pair by clicking the Generate button. When the progress bar starts loading, move your mouse randomly across the area to load up the bar and generate your key pair. Your public SSH key will be displayed on the screen. Nov 10, 2011 How to Generate A Public/Private SSH Key Linux By Damien – Posted on Nov 10, 2011 Nov 18, 2011 in Linux If you are using SSH frequently to connect to a remote host, one of the way to secure the connection is to use a public/private SSH key so no password is transmitted over the network and it can prevent against brute force attack. PuTTYgen is a key generator tool for creating pairs of public and private SSH keys. It is one of the components of the open-source networking client PuTTY. Although originally written for Microsoft Windows operating system, it is now officially available for multiple operating systems including macOS, Linux.

Puttygen aka Putty Key Generator

The key generation utility – PuTTYgen can create various public-key cryptosystems including Rivest–Shamir–Adleman (RSA), Digital Signature Algorithm (DSA), Elliptic Curve Digital Signature Algorithm (ECDSA), and Edwards-curve Digital Signature Algorithm (EdDSA) keys.

The aforementioned public-key cryptosystems principally focus on secure data transmission and digital signatures.

Although PuTTYgen collects keys in its native file format i.e. .ppk files, the keys can easily be converted to any file format. For Windows, the software interface is PuTTYgen.exe, whereas, for Linux OS the command-line adaptation is available using SSH commands.

How to use PuTTYgen?

PuTTYgen is used to generate public or private key pair for creating SSH keys. Below is the complete guidance about how to generate RSA key in the Windows operating system:

  1. Once you install the PuTTY on your machine, you can easily run PuTTYgen. For the same, go to Windows -> Start Menu -> All Programs -> PuTTY -> PuTTYgen.
  2. You will see the PuTTY key generator dialog box on your screen
  3. You will find a “Generate” button in that dialog. Clicking on it will lead to generating the keys for you.
  4. Now you will need to add a unique key passphrase in the Key passphrase and Confirm passphrase field.
  5. Click on the “Save Public Key” and “Save Private Key” buttons to save your public and private keys.
  6. You will see the text starting with ssh-RSA in the Public key for pasting into OpenSSH authorized_keys file field which is located at the top of the window. Copy that entire text to your clipboard by pressing ctrl+c as you will require the key to paste on your clipboard in the public key tool of control panel or directly on the cloud server.

Various Ways to Use RSA Key Pair

RSA key pair generated through PuTTYgen is used in two various ways defined as below:

  1. To assign while creating a new cloud server
    You can choose the public key from the given list of keys at the time of creating a cloud server. If you don’t find your key in that list, then first add and then assign it.
  2. Assign to an existing cloud server
    At the time of connecting to the cloud server, first of all, you need to tell PuTTY to use it for utilizing your newly created RSA key pair.

PuTTYgen being a component of the terminal emulator PuTTY does not have to be downloaded separately, hence, comes with the PuTTY .msi installation package. You can follow the simple steps to download PuTTYgen software for your system. That is the reason why you don’t need to download PuTTYgen separately. Once you download PuTTY software, you will be able to install and run PuTTYgen easily in no time. Below is the complete instruction about how to download and install PuTTY on Windows.

Apart from that, it is also integrated into third-party programs such as WinSCP installation package. Below you can find a complete PuTTYgen download and installation guide for all operating systems.

Download PuTTYgen on Windows

To download PuTTYgen the primary requisite is to acquire the copy of PuTTY installation package. For the 64-bit operating system, one must install the 64-bit version of PuTTY, i.e. putty-64bit-<version>-installer.msi.Similarly, for the 32-bit operating system, the respective 32-bit version of PuTTY, i.e. putty-<version>-installer.msi needs to be installed.

To get PuTTY, go to PuTTY Installation Download page, whereby the complete installation package will be available with setup instructions, installation guide, and download links to all other components of PuTTY such as putty.exe, pscp.exe, psftp.exe, puttytel.exe, plink.exe, pageant.exe and putty.zip.


Following the successful download of the PuTTY installation package. It is time to install the program. Go to How to install PuTTY on Windows, whereby you will find the step by step guidance for PuTTY installation for Windows operating system.

After successfully downloading and installing PuTTY on your Windows machine, you are just 2-3 clicks away to run PuTTYgen. Follow the below-given step by step guidance to run PuTTYgen:

Run PuTTYgen on Windows

To run PuTTYgen, Go to Windows -> Start Menu -> All Programs -> PuTTY -> PuTTYgen. You will see a window for the PuTTY Key Generator on your screen.

Voila! Now you can generate public or private key pair using PuTTYgen.

Download PuTTYgen for Mac


Below is the detailed guide to download PuTTYgen on Mac operating system. Mac OS has a built-in command-line SSH client known as Terminal. To utilize it, go to Finder and then opt for Go -> utilities from the top menu. After that find the terminal which supports SSH connections to remote servers.

However, to run PuTTYgen for mac, the first one must have to install PuTTY. There are multiple ways to install PuTTY, which are Homebrew or MacPorts. Both alternatives will also install the command-line of adaptations of PuTTYgen.

Ported PuTTY for Mac

Mac has the port of PuTTY which can be installed in various ways described as below:

  1. Installation using Homebrew:
    First, install the ‘brew command line’ Once installed use the below-given command to install PuTTY:-
    sudo brew install putty
  2. Installation using MacPorts:
    First of all, one must install MacPorts and then use the command-line to install PuTTY. Here is the command to install PuTTY via MacPorts
    sudo port install putty
    Additionally, a user can also add a shortcut to the desktop by writing the following command line
    –cp /opt/local/bin/putty ~/Desktop/PuTTY

However, there is an alternative way to install PuTTY on Mac OS. Cyberduck is a widely used Mac OS SSH Client. Once PuTTY installed on the Mac OS, a user can convert PuTTY derived private key format to OpenSSH.

To convert the private key to standard PEM format, type the following command –

puttygen privatekey.ppk -O private-openssh -o privatekey.pem

You can also read the guide to convert .pem file to .ppk using puttygen.

Download PuTTYgen for Ubuntu/Linux

To download PuTTYgen for Ubuntu (Linux) operating system, a user to first install PuTTY. However, in some Linux distributions, the SSH key generation tool – PuTTYgen needs to be installed independently from the PuTTY client.

For example, Debian Linux requires the below-given code to install PuTTYgen:

sudo apt install putty-tools

Generate Key Pair for Authentication in Linux

To create the key pair for authentication in Linux use the below command:-

puttygen -t rsa -b 2048 -C 'user@host' -o keyfile.ppk

Various Command Line Options of PuTTY in Linux

Below are few important command line options in the Linux operating system for PuTTY:

PuTTYgen [-t keytype [-b bits] [-q] keyfile]
[-C new-comment] [-P]
[-O output-type -p -l -L]
[-o output-file]

Options:

  1. Keyfile – It is the name of the existing key file to read at the time of changing the current key.
  2. –t keytype – The command specifies the type of key to creating. Its acceptable values are RSA and dsa.rsa1.
  3. -b bits – This command specifies a total number of bit in a particular key. 1024 is the perfect size for DSA key, while 2048 or 4096 are the perfect size for RSA keys.
  4. –q – The command suppresses the message about progress at the time of key generation.
  5. -C new-comment – The command will specify the comment to describe the key. It can be used for the new and/or existing key. Key operation is not affected by a comment. However, it is used to recognize the key owner, it’s not reliable completely as any value can be applied to it.
  6. –P – Using the command will update the passphrase of a key. Passphrase helps to encrypt the private key. As passphrase can’t add or update on a command line, it prompts a new passphrase tool to alter it.
  7. –old-passphrase-file – The old password of the key remains in this file. The command is used when the key is protected by a passphrase.
  8. –new-passphrase file – This command prompts the new passphrase of the key. It comes in the action either at the time of generating a new key or while applying –P command to change the passphrase.
  9. -O output-type – This command defines what to give in output. By default, the private key is the output.

Thus, above are the prominent commands of PuTTYgen in Linux operating system. Besides that, there are many other commands available to perform various tasks from the command prompt in Linux at flank speed.

Types of Keys Supported on PuTTYgen

It is important to know the types of key PuTTYgen supports prior to using it. Below are the key types that it currently supports for SSH-2 and SSH-1 protocol:-

  • SSH-1 protocol:- For SSH-1 only supports one key i.e. Rivest–Shamir–Adleman (RSA)
  • SSH-2 protocol: – SSH-2 supports multiple key types that include – Digital Signature Algorithm (DSA), Elliptic Curve Digital Signature Algorithm (ECDSA) and Ed25519.

The above description is a detailed brief on downloading and running PuTTYgen on all major operating systems. For further details please check the Download PuTTY page.

Verified and Tested 2/8/15

Introduction

This guide will show you how to generate and use SSH keys (public and private) using PuTTYgen and PuTTY for Linux servers.

How to Generate and Use an SSH Key

First thing’s first. We must generate our public and private keys using PuTTYgen. PuTTYgen and PuTTY can be downloaded here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html

Once they have been downloaded to a proper directory, open PuTTYgen first. Click on “Generate” to begin the key generation process. It will ask you to move your mouse around over the program window to help generate “random” data.

When the key is generated, the window will look like the picture below.

Sample public Key

Most of the information presented here is superfluous except in special instances. All you will want to do is update the “Key comment” box with a better friendly name for the key. Once you have done that, select all of the text in the “Key” box and paste it into Notepad or Notepad++ (preferred). Save that text file somewhere safe. You will also need to click “Save private key” on this window. Name it something useful and place it somewhere secure as well.

To use this key with a PuTTY connection, simply select the “Auth” menu on the left side of the program. This can be found under Connection -> SSH -> Auth. In this menu, there is a box titled “Private key file for authentication.” Click browse and find the .ppk file that you saved in the previous step.

At this point, if you name and save your connection in the “Session” category, you won’t ever have to follow this process again for that server/IP. Otherwise, you would need to choose your key each time you connect.

Creating a New Server with this SSH Key for Linux Servers

Putty Generate Ssh Key

Creating a cloud server that uses an SSH key is simple. You will first need to setup your key in the cloud portal.

Elcomsoft phone password breaker key generator

Putty

Click on “SSH Keys” on the left side under “Manage Servers.”

From there, click “Add SSH Key.”

When the window pops up, simply name your key, and paste the public key text (that you saved to a notepad file in a previous step) into the large box.

Cloud Portal:Add SSH Key

Click “Add Key.” If there were no issues with the key (inappropriate line breaks, errors, etc) it will save to the portal and be accessible for new servers.

To create a server that utilizes this key for root login, simply follow the “create server” steps found here.

Generate ssh key putty

-When choosing your server size and OS, you will see an option at the bottom that says “Pick SSH Key.” You will see the key we just created in that list. When the server comes online, simply use the previous PuTTY steps to connect to the server using that public key. The username will always be root when using our public key system.

Adding the Public SSH Key to an Existing Server

The steps for enabling public/private key login on a standard server that was not provisioned with a key originally is quite simple as well

Simply use PuTTY to log into the server as usual using the root account and password. You may already want to save a PuTTY profile with your key, even though the server will reject it until it is configured.

For all Linux-based operating systems, you only need to create root’s .ssh directory, and paste the public key into a file named “authorized_keys”

From here, you can either use a text editing program to paste the key in (vi/vim/nano, etc), or you can use echo. The echo command would look something like this:

At this point, you can log out of the server and log in using the previously stated method to open a PuTTY session with a private key attached. Upon entering the username “root”, the server should allow you to login without entering a password. If successful, you should see a message that states “Authenticating with public key.” The screenshot below has an example:

Generate Ssh Public Key Putty

Sample Log in

Add Ssh Key To Putty

Done! At this point, if you plan to access the server often, you will definitely want to save a profile. You can also setup a username to auto-login with under Data -> “Auto-login username.” Simply type root into that box and save it along with the private key and IP address to a PuTTY profile, and you can have instant passwordless login access to your server!

For more information about PuTTY, visit https://www.putty.org/.
For more information about PuTTYgen, visit https://www.puttygen.com/.