Putty Generate Ssh Key Command Line

Puttygen is the SSH key generation tool for the linux version of PuTTY. It works similarly to the ssh-keygen tool in OpenSSH. 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 key formats.

If the directory.ssh does not exist, execute the command mkdir.ssh followed by chmod 700.ssh; Use your favorite command text editor (mine is emacs) to open up /.ssh/authorizedkeys which should be an empty file. If it does not exist, create it; From the PuTTY Key Generator window copy the key as shown in the image below. In the PuTTY Configuration dialog, navigate to Connection SSH Auth. In the Private key file for authentication field, specify the path to your private key file and click Open. In the command line window, specify the username that you use for the SSH tunnel and press Enter. Do not close the command line.

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. Is it possible to use Putty Key Generator via command line interface? I cannot find any documentation. Any pointers? Btw, I only want to generate a openssh formatted key pair on a windows machine. SiteGround uses key-based authentication for SSH. This has proven more secure over standard username/password authentication. More information on SSH keys can be found here. You can generate an SSH key pair directly in cPanel, or you can generate the keys yourself and just upload the public one in cPanel to use with your hosting account. If you using a Linux or Mac based Operating System, you don’t need a client like PuTTY as Linux has its own SSH terminal. You just need to use the following command to connect to the server: ssh user@serverip. This command will connect you to a server whose IP address is “serverip”.

Overview

Public key authentication is a way of logging into an SSH/SFTP account using a cryptographic key rather than a password.

If you use very strong SSH/SFTP passwords, your accounts are already safe from brute force attacks. However, using public key authentication provides many benefits when working with multiple developers. For example, with SSH keys you can

  • allow multiple developers to log in as the same system user without having to share a single password between them;
  • revoke a single developer's access without revoking access by other developers; and
  • make it easier for a single developer to log in to many accounts without needing to manage many different passwords.

How Public Key Authentication Works

Keys come in pairs of a public key and a private key. Each key pair is unique, and the two keys work together.

These two keys have a very special and beautiful mathematical property: if you have the private key, you can prove you have it without showing what it is. It's like proving you know a password without having to show someone the password.

Public key authentication works like this:

  1. Generate a key pair.
  2. Give someone (or a server) the public key.
  3. Later, anytime you want to authenticate, the person (or the server) asks you to prove you have the private key that corresponds to the public key.
  4. You prove you have the private key.

You don't have to do the math or implement the key exchange yourself. The SSH server and client programs take care of this for you.

Generate an SSH Key Pair

You should generate your key pair on your laptop, not on your server. All Mac and Linux systems include a command called ssh-keygen that will generate a new key pair.

If you're using Windows, you can generate the keys on your server. Just remember to copy your keys to your laptop and delete your private key from the server after you've generated it.

To generate an SSH key pair, run the command ssh-keygen.

It will look like this when you run it:

You'll be prompted to choose the location to store the keys. The default location is good unless you already have a key. Press Enter to choose the default location.

Next, you'll be asked to choose a password. Using a password means a password will be required to use the private key. It's a good idea to use a password on your private key.

After you choose a password, your public and private keys will be generated. There will be two different files. The one named id_rsa is your private key. The one named id_rsa.pub is your public key.

You'll also be shown a fingerprint and 'visual fingerprint' of your key. You do not need to save these.

Configure an SSH/SFTP User for Your Key

Method 1: Using ssh-copy-id

Now that you have an SSH key pair, you're ready to configure your app's system user so you can SSH or SFTP in using your private key.

To copy your public key to your server, run the following command. Be sure to replace 'x.x.x.x' with your server's IP address and SYSUSER with the name of the the system user your app belongs to.

Method 2: Manual Configuration

If you don't have the ssh-copy-id command (for example, if you are using Windows), you can instead SSH in to your server and manually create the .ssh/authorized_keys file so it contains your public key.

Putty Command List

First, run the following commands to make create the file with the correct permissions.

Next, edit the file .ssh/authorized_keys using your preferred editor. Copy and paste your id_rsa.pub file into the file.

Log In Using Your Private Key

You can now SSH or SFTP into your server using your private key. From the command line, you can use:

If you didn't create your key in the default location, you'll need to specify the location:

Putty Generate Ssh Key Command Line Code

If you're using a Windows SSH client, such as PuTTy, look in the configuration settings to specify the path to your private key.

Granting Access to Multiple Keys

The .ssh/authorized_keys file you created above uses a very simple format: it can contain many keys as long as you put one key on each line in the file.

If you have multiple keys (for example, one on each of your laptops) or multiple developers you need to grant access to, just follow the same instructions above using ssh-copy-id or manually editing the file to paste in additional keys, one on each line.

When you're done, the .ssh/authorized_keys file will look something like this (don't copy this, use your own public keys):

Additional Information

Retrieve Your Public Key from Your Private Key

The following command will retrieve the public key from a private key:

Generate Ssh Key Windows

This can be useful, for example, if your server provider generated your SSH key for you and you were only able to download the private key portion of the key pair.

Note that you cannot retrieve the private key if you only have the public key.

Correcting Permissions on the .ssh Directory

The instructions in this article will create your server's .ssh directory and .ssh/authorized_keys file with the correct permissions. However, if you've created them yourself and need to fix permissions, you can run the following commands on your server while SSH'd in as your app's system user.

Disabling Password Authentication

Running Putty From Command Line

NOTE: When changing anything about the way SSH is accessed(ports, authentication methods, et cetera), it is very strongly recommended to leave an active root SSH session open until everything is working as intended. This ensures you have a way to revert changes in the event something goes wrongand logins are not working properly.

As an extra security precaution, once you have set up SSH keys, you may wish to disable password authentication entirely. This will mean no users will be able to log into SSH or SFTP without SSH keys. Anyone entering a password will receive a message like:

Or:

Disabling password authentication is an excellent way to improve server security. Please see our guide here for the steps to accomplish this goal.

Then, test whether you're able to log in with a password by opening a new SSH or SFTP session to the server. Passwords should not be able to be used and, if everything has been done correctly, an error will be issued when someone tries to use a password. Unless this setting is changed back to allow password authentication, no users will be able to log in without an SSH key set up.

The PuTTYgen program is part of PuTTY, an open source networking client for the Windows platform.

To generate an SSH key pair on Windows using the PuTTYgen program:
Putty Generate Ssh Key Command Line
  1. Download and install PuTTY or PuTTYgen.

    To download PuTTY or PuTTYgen, go to http://www.putty.org/ and click the You can download PuTTY here link.

  2. Run the PuTTYgen program.
  3. Set the Type of key to generate option to SSH-2 RSA.
  4. In the Number of bits in a generated key box, enter 2048.
  5. Click Generate to generate a public/private key pair.

    As the key is being generated, move the mouse around the blank area as directed.

  6. (Optional) Enter a passphrase for the private key in the Key passphrase box and reenter it in the Confirm passphrase box.

    Note:

    While a passphrase is not required, you should specify one as a security measure to protect the private key from unauthorized use. When you specify a passphrase, a user must enter the passphrase every time the private key is used.

  7. Click Save private key to save the private key to a file. To adhere to file-naming conventions, you should give the private key file an extension of .ppk (PuTTY private key).

    Note:

    The .ppk file extension indicates that the private key is in PuTTY's proprietary format. You must use a key of this format when using PuTTY as your SSH client. It cannot be used with other SSH client tools. Refer to the PuTTY documentation to convert a private key in this format to a different format.
  8. Select all of the characters in the Public key for pasting into OpenSSH authorized_keys file box.

    Make sure you select all the characters, not just the ones you can see in the narrow window. If a scroll bar is next to the characters, you aren't seeing all the characters.

  9. Right-click somewhere in the selected text and select Copy from the menu.
  10. Open a text editor and paste the characters, just as you copied them. Start at the first character in the text editor, and do not insert any line breaks.
  11. Save the text file in the same folder where you saved the private key, using the .pub extension to indicate that the file contains a public key.
  12. If you or others are going to use an SSH client that requires the OpenSSH format for private keys (such as the ssh utility on Linux), export the private key:
    1. On the Conversions menu, choose Export OpenSSH key.
    2. Save the private key in OpenSSH format in the same folder where you saved the private key in .ppk format, using an extension such as .openssh to indicate the file's content.