# PuTTY (Windows)

## Windows PuTTY Installer

We recommend you to download "**A Windows installer for everything except PuTTYtel**" with **Pageant** (SSH authentication agent) and **PuTTYgen** (PuTTY key generator) which is available [here][a].

!!! note
    After installation, you can proceed directly to private keys authentication using ["Putty"][1].

    "Change Password for Existing Private Key" is optional.

    "Generate a New Public/Private key pair" is intended for users without Public/Private key in the initial email containing login credentials.

    "Pageant" is optional.

## PuTTY - How to Connect to the IT4Innovations Cluster

* Run PuTTY
* Enter Host name and Save session fields with login address and browse Connection -  SSH - Auth menu. The _Host Name_ input may be in the format **"username@clustername.it4i.cz"** so you do not have to type your login each time. In this example, we will connect to the Salomon cluster using **"salomon.it4i.cz"**.

![](../../../img/PuTTY_host_Salomon.png)

* Category - Connection -  SSH - Auth:
      Select Attempt authentication using Pageant.
      Select Allow agent forwarding.
      Browse and select your [private key][2] file.

![](../../../img/PuTTY_keyV.png)

* Return to Session page and Save selected configuration with _Save_ button.

![](../../../img/PuTTY_save_Salomon.png)

* Now you can log in using _Open_ button.

![](../../../img/PuTTY_open_Salomon.png)

* Enter your username if the _Host Name_ input is not in the format "username@salomon.it4i.cz".
* Enter passphrase for selected [private key][2] file if Pageant **SSH authentication agent is not used.**

## Another PuTTY Settings

* Category - Windows - Translation - Remote character set and select **UTF-8**.
* Category - Terminal - Features and select **Disable application keypad mode** (enable numpad)
* Save your configuration on Session page in to Default Settings with _Save_ button.

## Pageant SSH Agent

Pageant holds your private key in memory without needing to retype a passphrase on every login.

* Run Pageant.
* On Pageant Key List press _Add key_ and select your private key (id_rsa.ppk).
* Enter your passphrase.
* Now you have your private key in memory without needing to retype a passphrase on every login.

![](../../../img/PageantV.png)

## PuTTY Key Generator

PuTTYgen is the PuTTY key generator. You can load in an existing private key and change your passphrase or generate a new public/private key pair.

### Change Password for Existing Private Key

You can change the password of your SSH key with "PuTTY Key Generator". Make sure to back up the key.

* Load your [private key][2] file with _Load_ button.
* Enter your current passphrase.
* Change key passphrase.
* Confirm key passphrase.
* Save your private key with the _Save private key_ button.

![](../../../img/PuttyKeygeneratorV.png)

### Generate a New Public/Private Key

You can generate an additional public/private key pair and insert public key into authorized_keys file for authentication with your own private key.

* Start with _Generate_ button.

![](../../../img/PuttyKeygenerator_001V.png)

* Generate some randomness.

![](../../../img/PuttyKeygenerator_002V.png)

* Wait.

![](../../../img/PuttyKeygenerator_003V.png)

* Enter a comment for your key using the 'username@organization.example.com' format.
      Enter a key passphrase, confirm it and save your new private key in the _ppk_ format.

![](../../../img/PuttyKeygenerator_004V.png)

* Save the public key with the _Save public key_ button.
      You can copy public key out of the ‘Public key for pasting into the authorized_keys file’ box.

![](../../../img/PuttyKeygenerator_005V.png)

* Export the private key in the OpenSSH format "id_rsa" using Conversion - Export OpenSSH key

![](../../../img/PuttyKeygenerator_006V.png)

* Now you can insert an additional public key into the authorized_keys file for authentication with your own private key.
      You must log in using the SSH key received after registration. Then proceed to [How to add your own key][2].

[1]: #putty
[2]: ssh-keys.md#how-to-add-your-own-key

[a]: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html