PuTTYgen is an key generator tool for creating SSH keys for PuTTY. It is analogous to the ssh-keygen tool used in some other SSH implementations. The basic function is to create public and private key pairs. PuTTY stores keys in its own format in.ppk files. However, the tool can also convert keys to and from other formats. To generate a key with PuTTY, you should: Download and start the puttygen.exe generator. In the 'Parameters' section choose SSH2 DSA and press Generate. Move your mouse randomly in the small screen in order to generate the key pairs. Enter a key comment, which will identify the key (useful when you use several SSH keys).
You have seen in previous tutorials how to use PuTTY to connect to your VPS securely and how to create SSH keys with PuTTYgen.
You might have more than one SSH key for a single cloud server, or simply more than one cloud server or Droplet that requires SSH keys to log into. This can make you feel overwhelmed with having to manage, sort out, and link all those keys to their respective servers. That’s why Pageant exists.
Pageant is a PuTTY authentication agent. It holds your private keys in memory so that you can use them whenever you are connecting to a server. It eliminates the need to:
Make sure you have these prerequisites.
Start Pageant from the PuTTY folder: Start-Menu > All Programs > PuTTY > Pageant
Pageant starts by default minimized in the system tray. To begin adding your SSH keys, you should right click on its icon and then the following context menu will show up:
Clicking on Add Key from the menu or View Keys to open up the Pageant Key List window. Here you can view, add, and remove keys:
Tip: You can access the Pageant Key List window directly by double-clicking its icon in the system tray.
Click the Add Key button. This will open the file explorer, where you can choose one or more keys at a time to load. You should select files with the .ppk extension:
Click the Open button to load the keys with Pageant.
If a key is passphrase-protected, you will be prompted to enter the passphrase only once before it can be added to the Pageant Key List:
After successfully adding a key, you can now see it listed:
Now these keys will be available while connecting to any server during your PuTTY sessions. You don’t have to take any extra steps in PuTTY. Just enter your hostname or IP address, and SSH user. PuTTY will automatically try to authenticate using any keys currently loaded in Pageant.
If you want to remove a key from Pageant, select that key from the Pageant Key List window and press the Remove Key button. You can also remove multiple keys together by selecting them with CTRL or SHIFT.
Use these tips to automate your authenticated connections with Pageant.
You can make Pageant automatically load one or more private keys when it starts up, instead of adding them manually every time you start up Pageant.
Go to the Pageant shortcut icon from the Windows Start Menu or your desktop.
Right click on the icon, and click on Properties.
A new window will open containing the shortcut’s properties:
From the Shortcut tab, edit the Target field. Leave the path to pageant.exe intact. After that path, add paths to your .ppk key files. These should be outside the quotation marks. Here’s an example:
Click the Apply and then OK buttons.
Note: If the keys are encrypted, Pageant will request the passphrases on startup.
You can make Pageant start PuTTY or any other program once it has initialized itself and loaded any keys specified on its command line. That way you can just start Pageant instead of having to start both programs.
You can achieve this by following the same steps we used previously to add the keys automatically (see the previous section). Just add the program’s path at the end of the command in the Target field, preceded by the -c option, and contained within double quotes. Here’s an example of the full line for the Target field:
Here are a few other helpful applications that can work with PuTTY.
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.
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.
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:
Various Ways to Use RSA Key Pair
RSA key pair generated through PuTTYgen is used in two various ways defined as below:
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.
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:
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.
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.
Mac has the port of PuTTY which can be installed in various ways described as below:
sudo brew install putty
sudo port install putty
–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.
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
To create the key pair for authentication in Linux use the below command:-
puttygen -t rsa -b 2048 -C 'user@host' -o keyfile.ppk
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:
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.
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:-
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.