Ssh identity key file

Learn more. What does identity file type mean in SSH debug messages? Ask Question. Asked 3 years, 2 months ago. Active 2 years ago. Viewed 15k times. I've been debugging a SSH connection using the following command: ssh -vT user mysite. Thank you so much in advance.

Improve this question. Jakuje 6, 7 7 gold badges 25 25 silver badges 37 37 bronze badges. Add a comment. Active Oldest Votes. Improve this answer. 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 a user name provided against the private key. If the server-side public key cannot be validated against the client-side private key, authentication fails. Multi-factor authentication may be implemented with key pairs by entering a passphrase when the key pair is generated see user 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. Public keys have specific ACL requirements that, on Windows, equate to only allowing access to administrators and System.

On first use of sshd, the key pair for the host will be automatically generated. By default the sshd service is set to start manually. To start it each time the server is rebooted, run the following commands from an elevated PowerShell prompt on your server:. If no algorithm is specified, RSA is used.

A strong algorithm and key length should be used, such as Ed in this example. To generate key files using the Ed algorithm, run the following from a PowerShell or cmd prompt on your client:. This browser is no longer supported. Download Microsoft Edge More info. Contents Exit focus mode. Please rate your experience Yes No. Any additional feedback? In this article. 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 stay 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 keys for username provided against the private key. If the server-side 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. Public keys have specific ACL requirements that, on Windows, equate to only allowing access to administrators and System. To make this easier,.

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. 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.

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. 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.

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. The OpenSSH tools include scp, which is a secure file-transfer utility, to help with this.