---
title: "Configure SSH Keys on Your Server | Hostman Docs"
description: "Learn how to generate SSH keys on Linux, Windows, and MacOS for secure connection to your server. Check our step-by-step guides for working with Hostman cloud infrastructure and services."
---

> For the complete documentation index for AI agents, see [llms.txt](https://hostman.com/llms.txt).

In this article, we will look at how to create SSH keys on devices with different operating systems and how to copy them to a server for SSH connections.

## Create SSH Keys

Follow these steps to create an SSH key pair on your local machine.

> [!NOTE]
> This guide will work for Linux, MacOS, and the newer versions of Windows 10 starting from 1809, which have a built-in SSH client. If you have an older version of Windows, you will need to use an SSH client such as PuTTY.

1.  Launch a terminal or Windows PowerShell on your computer and run the command:
    

```shell
ssh-keygen
```

2.  You will see a similar message:
    

```shell
Generating public/private rsa key pair.
```

Enter file in which to save the key (`/home/user/.ssh/id_rsa`):

3.  Press Enter to save the key to the default directory.
    
4.  Next, set a passphrase or press Enter to leave it blank. Using a passphrase increases security, but you will have to enter it every time you log in to the server.
    

That’s it; the keys are created. 

The private key will be stored on your machine, while the public key should be copied to the server. This can be done manually [as described below](https://hostman.com/docs/cloud-servers/administration/configure-ssh-keys/#copy-an-ssh-key-to-the-server) or, more conveniently, by [using your Hostman dashboard](https://hostman.com/docs/cloud-servers/ssh-keys/#add-an-ssh-key-to-a-new-server).

## Create SSH Keys with PuTTY

Old Windows versions don’t have OpenSSH, so you'll need a special program, PuTTYgen. You can download the `puttygen.exe` distribution from the official PuTTY website.

1.  Launch the program.
    
2.  Select **RSA** in the **Type of key** **to generate** block and click **Generate**.
    
3.  Move your mouse randomly in the space below the loading line to generate random values.
    
4.  After the key is created, you can set the Key passphrase. This is optional; you can leave the line blank. If you choose to set a passphrase, please note that you will need to enter it each time you log in using the key.
    
5.  Next, save the created keys by clicking on the **Save public key** and **Save private key** buttons, for example, as `id_rsa.pub` and `mykey.ppk`.
    
6.  Also, copy and save the contents of the **Public key for pasting...** window as a text file, as you will need them later when copying the SSH key to the server or the Hostman panel.
    

## Copy an SSH Key to the Server

> [!NOTE]
> You can also transfer the public SSH key to the server [via the Hostman dashboard](https://hostman.com/docs/cloud-servers/ssh-keys/#add-an-ssh-key-to-a-new-server).

Run the following command on your local computer's terminal. In place of user, enter a username created on the server, and in place of server, enter the server IP address.

### Linux and MacOS

```shell
ssh-copy-id user@server
```

For example:

```shell
ssh-copy-id root@38.62.228.244
```

### Windows

```shell
type $env:USERPROFILE\.ssh\id_rsa.pub | ssh user@server "cat >> .ssh/authorized_keys"
```

For example:

```shell
type $env:USERPROFILE\.ssh\id_rsa.pub | ssh root@38.62.228.244 "cat >> .ssh/authorized_keys"
```

As a result, the contents of the `id_rsa.pub` file with the public key will be copied to the `~/.ssh/authorized_keys` file on the server, and in the future, you will be able to establish a connection to the server using the command:

```shell
ssh user@server
```

For example:

```shell
ssh root@38.62.228.244
```

### Windows (with PuTTY)

On older Windows versions, you will need the `pageant` utility to copy the SSH key to your server. You can download the `pageant.exe` distribution from the official PuTTY website.

1.  Connect to the server via SSH via Putty and run the command to create a file on the server to store keys:
    

```shell
chmod 0700 ~/.ssh
touch ~/.ssh/authorized_keys
chmod 0644 ~/.ssh/authorized_keys
```

2.  Open the file:
    

```shell
nano ~/.ssh/authorized_keys
```

3.  Paste the text public key, previously copied from the PuTTYgen window, into it and save the file.
    
4.  Launch `pageant`. Its icon will appear in the tray. Right-click on it and select **Add Key**.
    
5.  Enter the path to the private key `mykey.ppk`, saved earlier, and click **Open**. If you added a passphrase when creating the key, pageant will ask for it at this stage.
    

To check that key authorization works, run PuTTY, connect to your server, and enter your login. If everything is configured correctly, you will see an output similar to this in the console window:

```shell
Authenticating with public key "rsa-key-20151220" from agent
```

## Disable Password Authentication

You can disable password authentication on your server to ensure that it can only be accessed with the SSH key. To do this, you need to edit the `/etc/ssh/sshd_config` file on your server.

1.  Connect to the server via SSH and open the file with the command:
    

```shell
sudo nano /etc/ssh/sshd_config
```

2.  Find the `PasswordAuthentication` line in it and replace its value with:
    

```shell
PasswordAuthentication no
```

3.  Save the changes, then restart the SSH service:  
    

```shell
sudo service ssh restart
```

## Troubleshooting

If you are unable to connect using an SSH key, check the SSH logs on the server:

```shell
sudo journalctl -u ssh
```

If the logs contain the following entry:

```shell
userauth_pubkey: key type ssh-rsa not in PubkeyAcceptedAlgorithms [preauth]
```

this indicates that support for `ssh-rsa` (RSA with SHA-1) is disabled on the server. In this case, you can resolve the issue using one of the following approaches.

**Option 1 (Recommended)**. Generate a new key using a more secure algorithm.

For a stronger RSA key:

```shell
ssh-keygen -t rsa -b 4096 -o -a 100
```

Alternatively, generate an Ed25519 key:

```shell
ssh-keygen -t ed25519
```

After generating the key, upload the new public key to the server.

**Option 2.** Allow authentication using `ssh-rsa` by updating the SSH daemon configuration.

Add the following line to `/etc/ssh/sshd_config.d/enable_rsa_keys.conf`:

```shell
HostKeyAlgorithms +ssh-rsa
PubkeyAcceptedKeyTypes +ssh-rsa
```

Then restart the SSH service:

```shell
sudo systemctl restart sshd
```