SSH

Creating Keys with the Public-Key Authentication Wizard

On Windows and Linux, you can use the Tectia Public-Key Authentication Wizard to generate a key pair and to upload a public key to a host, see Public-Key Generation and Uploading Public Keys Automatically. The wizard will generate two key files, your private key and your public key.

The new private and public key will be stored on your local computer in the %APPDATA%\SSH\UserKeys directory on Windows and in the $HOME/.ssh2/ directory on Linux. The private key file has no file extension, and the public key has the same base file name as the private key, but with .pub as the file extension.

Make sure that public-key authentication is allowed in the Connection Broker configuration, in the default settings and in the relevant connection profile (it is allowed by default). For the default settings, see Defining Authentication, and for the connection profile, see Defining Authentication.

To use the key pair for public-key authentication, you have to upload the public key to the remote host computer. If the remote host has an SFTP server running, you can automatically upload a copy of your new public key to the server with the wizard. To upload the key automatically, see Uploading Public Keys Automatically. To upload the key manually, see Uploading Public Keys Manually.

Public-Key Generation

New keys are generated in the Tectia Connections Configuration GUI. Under User authentication, select the Keys and Certificates page and click New Key to start the Public-Key Authentication Wizard.

The Public-Key Authentication Wizard

Figure 4.5. The Public-Key Authentication Wizard


Define the key properties and the required passphrase to protect your private key; you will be requested to enter the passphrase always when using the keys to authenticate yourself.

File name

Type a unique name for the key file. Tectia Client suggest a name consisting of the user name and the host name.

Comment

In this field you can write a short comment that describes the key pair. You can for example describe the connection the keys are used for. This field is not obligatory, but helps to identify the key later.

Passphrase

Type a phrase that you have to enter when handling the key. This passphrase works in a similar way to a password and gives some protection for your private key.

[Note]Note

In FIPS mode, due to a FIPS regulation which forbids exporting unencrypted private keys out of the FIPS module, it is not possible to generate user keys without a passphrase.

Make the passphrase difficult to guess. Use ideally at least 20 characters, both letters and numbers. Any punctuation characters can be used as well. While the passphrase or private key is never sent over the network, a dictionary attack can be used against a private key if it is accessible locally. For ease of use, an authentication agent is recommended instead of leaving the passphrase empty. By default ssh-broker-g3 functions as an authentication agent.

Memorize the passphrase carefully, and do not write it down.

Retype passphrase

Type the passphrase again. This ensures that you have not made a typing error.

Click Advanced Options to define the type of the key to be generated and the key length to be different from the defaults. By default, Tectia Client generates a pair of 3072-bit RSA keys.

In the Key Properties fields, you can make the following selections:

Key type

Select the type of the key to be generated. Available options are Ed25519 RSA (default), ECDSA and DSA.

[Note]Note

In FIPS mode (conforming to FIPS 186-5) RSA, ECDSA and Ed25519 are supported. DSA has been deprecated.

Key length

Select the length (complexity) of the key to be generated. Available options are:

  • DSA/RSA keys: 2048, 3072, 4096, 5120, 6144, 7168, 8192 bits

  • ECDSA keys: 256, 384, 521 bits

  • Ed25519 keys: 256 bits

Larger keys of the same key type are more secure, but also slower to generate. A 256-bit ECDSA key and a 3072-bit RSA key provide equivalent security.

Click Next to proceed to uploading the key as instructed in Uploading Public Keys Automatically.

Uploading Public Keys Automatically

Public keys can be uploaded automatically to servers that have the SFTP subsystem enabled. The Public-Key Authentication Wizard automatically uploads each new public key to a remote host of your choice. The wizard lists all existing keys, and you can select a key to upload it also to other remote servers at any time.

To access the Public-Key Authentication Wizard, click User Authentication → Keys and Certificates on the tree view.

Select a key from the Key and Certificate List and click Upload.

In the Upload Public Key view of the wizard, define the remote host where to upload the key:

Uploading a key

Figure 4.6. Uploading a key


Quick connect

Select this option to define the remote Host name and your User name there. The default Secure Shell port is 22.

Connection profile

Select from the drop-down list the connection profile that specifies the desired remote host and user name.

Click Upload to upload the key to the selected server. If you are already connected to the remote server host, the key upload starts immediately. If you are not connected, you will be prompted to authenticate on the server (by default with password).

The public key will be uploaded to the default user home directory (%USERPROFILE%\.ssh2 on Windows, $HOME/.ssh2 on Unix).

[Note]Note

The key user is required to have the write permissions to the key directory on the server, otherwise the automatic upload will fail. The administrator of the remote host computer may have restricted user access so that users are not able to configure public-key authentication for themselves even if public-key authentication is allowed in the server configuration.

Even if the automatic upload succeeds, it is possible that the server administrator has configured the system to store keys elsewhere than under the user home directory. In this case the keys and the authorization file additions have to be moved manually to the proper directory.

If you do not use the automatic upload facility, see Uploading Public Keys Manually.