Use the ssh-keygen command to generate a public/private authentication key pair. Authentication keys allow a user to connect to a remote system without supplying a password. Keys must be generated for each user separately. If you generate key pairs as the root user, only the root can use the keys.
Ssh Keygen Download
![Ssh Keygen Cmd](https://upload.wikimedia.org/wikipedia/commons/c/c3/Ssh-keygen_-t_rsa_-C_"gerrituser%40example.com".png "Ssh Keygen Cmd")
- Lonvick, The Secure Shell (SSH) Authentication Protocol, RFC 4252, January 2006. Lonvick, The Secure Shell (SSH) Transport Layer Protocol, RFC 4253, January 2006. Lonvick, The Secure Shell (SSH) Connection Protocol, RFC 4254, January 2006.
- Ssh-keygen -m PEM -t rsa -b 4096 If you use the Azure CLI to create your VM with the az vm create command, you can optionally generate SSH public and private key files using the -generate-ssh-keys option. The key files are stored in the /.ssh directory unless specified otherwise with the -ssh.
By default, the system will save the keys to C: Users yourusername.ssh idrsa. You can use the default name, or you can choose more descriptive names. This can help distinguish between keys, if you are using multiple key pairs. To stick to the default option, press Enter.
The following example creates the public and private parts of an RSA key:
Use the –t option to specify the type of key to create. Possible values are “rsa1” for protocol version 1, and “dsa“, “ecdsa“, or “rsa” for protocol version 2.
You have the option of specifying a passphrase to encrypt the private part of the key. If you encrypt your personal key, you must supply the passphrase each time you use the key. This prevents an attacker, who has access to your private key and can impersonate you and access all the computers you have access to, from being able to do so. The attacker still needs to supply the passphrase.
The ssh-key command in the example generated two keys in the ~/.ssh directory:
To log on to, or copy files to, a remote system without supplying a password, copy the public key (~/.ssh/id_rsa.pub in this example) to ~/.ssh/authorized_keys on the remote system. Set the remote ~/.ssh directory permissions to 700. You can then use the ssh or scp tools to access the remote system without supplying a password.
To allow multiple connections, append the public key to the authorized_keys file on the remote system instead of copying it. The following example appends the public key:
You can improve system security even further by disabling the standard password authentication, and enforcing the key-based authentication. To do so, set the PasswordAuthentication option to no in the /etc/ssh/sshd_config configuration file as follows:
Ssh Keygen Options
Ssh Keygen Linux
This disallows users whose keys are not in the authorized_keys file of the specific user on the server to connect via ssh. The connection is denied and the following message appears:
Ssh Keygen Cmd Commands
Setting the PasswordAuthentication option to yes, which is the default, permits a user to use a password for authentication.