Windows Generate Ssh Private Key

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Generate RSA keys with SSH by using PuTTYgen. Last updated on: 2016-06-23; Authored by: Rackspace Support; One effective way of securing SSH access to your cloud server is to use a public-private key pair. This means that a public key is placed on the server. Type in the passphrase and confirm it. The passphrase is used to protect your key. You will be asked for it when you connect via SSH. Click 'Save private key' to save your private key. Click 'Save public key' to save your public key. For more information on how to load the key and connect via SSH using PuTTY, please check this tutorial.

How to generate an SSH key in Windows 10

To generate an SSH key in Windows 10:

  1. Ensure the Windows 10 OpenSSH client is installed.
  2. Run “ssh-keygen” in Command Prompt and follow the instructions to generate your key.

Applies to Windows 10 1803, and up

Generating SSH keys in a Windows environment used to be a convoluted process which required the installation of third-party tools. Since the Windows 10 April 2018 update, Windows has shipped with a preinstalled OpenSSH client, which means you can use ssh-keygen to generate SSH keys. Read on as we walk you through the entire process.

First, you’ll need to make sure OpenSSH is installed on your machine – if you upgraded from an earlier version of Windows 10, you may need to manually enable it. Launch the Settings app and click the “Apps” category. Next, click the “Manage optional features” link. If you don’t see “OpenSSH Client” in the list which appears, click the “Add a feature” button and install it. You might need to reboot your PC after the installation.

Once OpenSSH is installed, you’re ready to proceed. Open Command Prompt from the Start menu. Type “ssh-keygen” (without the quotes) into the terminal window and press enter. You’ll be prompted to confirm the save location. We recommend pressing enter to use the default location in your user directory. Otherwise, type a path to save the key in and then press enter.

You can now choose to add a passphrase (password) to the key. If you add one, you’ll need to supply it whenever you use the key. Either type a passphrase and press enter or press enter immediately to proceed without one.

Windows will now generate your RSA public/private key pair. The public key will be stored as “id_rsa.pub” in the directory you specified. Upload this key to any machines you need to SSH into. You can then open a connection using Windows’ built-in SSH client – type “ssh [email protected]” to connect and authenticate using your generated credentials.

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Most authentication in Windows environments is done with a username-password pair.This works well for systems that share a common domain.When working across domains, such as between on-premise and cloud-hosted systems, it becomes more difficult.

Windows Generate Ssh Private Key Finder

By comparison, Linux environments commonly use public-key/private-key pairs to drive authentication.OpenSSH includes tools to help support this, specifically:

  • ssh-keygen for generating secure keys
  • ssh-agent and ssh-add for securely storing private keys
  • scp and sftp to securely copy public key files during initial use of a server

This document provides an overview of how to use these tools on Windows to begin using key authentication with SSH.If you are unfamiliar with SSH key management, we strongly recommend you review NIST document IR 7966 titled 'Security of Interactive and Automated Access Management Using Secure Shell (SSH).'

About key pairs

Key pairs refer to the public and private key files that are used by certain authentication protocols.

SSH public-key authentication uses asymmetric cryptographic algorithms to generate two key files – one 'private' and the other 'public'. The private key files are the equivalent of a password, and should protected under all circumstances. If someone acquires your private key, they can log in as you to any SSH server you have access to. The public key is what is placed on the SSH server, and may be shared without compromising the private key.

When using key authentication with an SSH server, the SSH server and client compare the public key for username provided against the private key. If the public key cannot be validated against the client-side private key, authentication fails.

Multi-factor authentication may be implemented with key pairs by requiring that a passphrase be supplied when the key pair is generated (see key generation below).During authentication the user is prompted for the passphrase, which is used along with the presence of the private key on the SSH client to authenticate the user.

Host key generation

Public keys have specific ACL requirements that, on Windows, equate to only allowing access to administrators and System.To make this easier,

% Attempt to generate RSA keys failed: Alittle background.customer of ours has this asa.out of nowhere loses all ssh capabilties. I confirmed that everythign looked good in the config and further zeroize'd the keys just to run them from scratch and create up a new batch.this is when I now cannot create them up again.Not sure how to proceed.Any help on this would be great! Asa 5505 attempt to generate rsa keys failed. Try re-generating the SSH key. Something like: crypto key generate rsa general-keys modulus 4096. Failing that try rebooting the ASA. Failing that, make sure you are using an up to date version of PuTTY, and enable stronger keys on the ASA with (your software might be too old for this): sh key-exchange group dh-group14-sha1.

  • The OpenSSHUtils PowerShell module has been created to set the key ACLs properly, and should be installed on the server
  • On first use of sshd, the key pair for the host will be automatically generated. If ssh-agent is running, the keys will be automatically added to the local store.

To make key authentication easy with an SSH server, run the following commands from an elevated PowerShell prompt:

Since there is no user associated with the sshd service, the host keys are stored under ProgramDatassh.

User key generation

To use key-based authentication, you first need to generate some public/private key pairs for your client.From PowerShell or cmd, use ssh-keygen to generate some key files.

This should display something like the following (where 'username' is replaced by your user name)

Windows Generate Ssh Private Key Authentication

You can hit Enter to accept the default, or specify a path where you'd like your keys to be generated.At this point, you'll be prompted to use a passphrase to encrypt your private key files.The passphrase works with the key file to provide 2-factor authentication.For this example, we are leaving the passphrase empty.

Now you have a public/private ED25519 key pair(the .pub files are public keys and the rest are private keys):

Windows Generate Ssh Private Key File

Remember that private key files are the equivalent of a password should be protected the same way you protect your password.To help with that, use ssh-agent to securely store the private keys within a Windows security context, associated with your Windows login.To do that, start the ssh-agent service as Administrator and use ssh-add to store the private key.

After completing these steps, whenever a private key is needed for authentication from this client, ssh-agent will automatically retrieve the local private key and pass it to your SSH client.

Note

It is strongly recommended that you back up your private key to a secure location,then delete it from the local system, after adding it to ssh-agent.The private key cannot be retrieved from the agent.If you lose access to the private key, you would have to create a new key pairand update the public key on all systems you interact with.

Deploying the public key

To use the user key that was created above, the public key needs to be placed on the server into a text file called authorized_keys under usersusername.ssh.The OpenSSH tools include scp, which is a secure file-transfer utility, to help with this.

To move the contents of your public key (~.sshid_ed25519.pub) into a text file called authorized_keys in ~.ssh on your server/host.

Windows Generate Ssh Private Key West

This example uses the Repair-AuthorizedKeyPermissions function in the OpenSSHUtils module which was previously installed on the host in the instructions above.

Ssh Private Key File

These steps complete the configuration required to use key-based authentication with SSH on Windows.After this, the user can connect to the sshd host from any client that has the private key.