How do I create a host key file to use with my applications as I can not use system defined /etc/ssh/ssh_host_rsa_key for non-root account under Linux / Unix / Apple OS X / *BSD operating systems?
You need to use a command called ssh-keygen. This command generates, manages and converts authentication keys for ssh. It can create RSA keys for use by SSH protocol version 1 and RSA or DSA keys for use by SSH protocol version 2. he type of key to be generated is specified with the -t option. If invoked without any arguments, ssh-keygen will generate an RSA key for use in SSH protocol 2 connections. The -f option specifies the filename of the key file.
You need to use a command called ssh-keygen. This command generates, manages and converts authentication keys for ssh. It can create RSA keys for use by SSH protocol version 1 and RSA or DSA keys for use by SSH protocol version 2. he type of key to be generated is specified with the -t option. If invoked without any arguments, ssh-keygen will generate an RSA key for use in SSH protocol 2 connections. The -f option specifies the filename of the key file.
GitHub Enterprise Server Authentication Connecting to GitHub with SSH Generating a new SSH key and adding it to the ssh-agent Generating a new SSH key and adding it to the ssh-agent After you've checked for existing SSH keys, you can generate a new SSH key to use for authentication, then add it to the ssh. Pick a name for the putty key, enter a name for it. Then click save. Using your ssh3 key with Putty. Pick a host and pick 'ssh' Pick SSH protocol 2; Tell it to use your ssh key by drilling down the menu path: Connection-SSH-ssh key: (see figures 7).
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![Freebsd Freebsd](/uploads/1/2/6/4/126450921/182965960.png)
Why create a new host key files?
![Freebsd ssh server Freebsd ssh server](https://www.ssh.com/s/ssh-keygen-user-key-728x467-BMs00tMu.png)
You may need a new key file:
- Your system is compromised.
- Your keys are stolen.
- You forgotten the passphrase.
- Your application need a new host key.
- You can not read the default system key files stored in /etc/ssh/ directory but your non-root application needs key.
- You got an error message which read as “Could not load host key: /etc/ssh/ssh_host_key*”.
ssh-keygen Syntax
The syntax is:
Example
Create a host key file in your $HOME/.ssh/myapp as follows. First, create a directory to store your host key file, enter:
To create a host RSAv2 key file, run:
Sample outputs:
$ mkdir -p $HOME/.ssh/myapp
To create a host RSAv2 key file, run:
$ ssh-keygen -t rsa -f $HOME/.ssh/myapp/rsa_key_file
Sample outputs:
Type the following commands to verify the keys:
Sample outputs:
$ ls -l $HOME/.ssh/myapp/
Sample outputs:
You can now use keys with your app:
$ mycool-app -key $HOME/.ssh/myapp/rsa_key_file -d
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The SSH protocol recommended a method for remote login and remote file transfer which provides confidentiality and security for data exchanged between two server systems. The SSH depends upon the use of public key cryptography. The OpenSSH server offers this kind of setup under Linux or Unix-like system. This how-to covers generating and using ssh public keys for automated usage such as:
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- Automated Login using the shell scripts
- Making backups
- Run commands from the shell prompt and more
- Login without password
How to configure SSH Public key-based authentication for a Linux/Unix
The steps and commands are as follows:
- On your local system type: ssh-keygen
- Install public key into remote server: ssh-copy-id user@remote-server-ip-name
- Use ssh for password less login: ssh user@remote-server-ip-name
Let us see all commands in details.
Generating SSH Keys
First, log on to your workstation. For example, log on to workstation called admin.fbsd.nixcraft.org as vivek user. Please refer the following sample setup. You will be logged in, on your local system, AS THE USER you wish to make passwordless ssh connections.
To create the cryptographic keys on your local system powered by FreeBSD/Linux/macOS/ UNIX workstation, enter:
Assign the pass phrase (press [enter] key twice if you don’t want a passphrase). It will create 2 files in ~/.ssh directory as follows:
To create the cryptographic keys on your local system powered by FreeBSD/Linux/macOS/ UNIX workstation, enter:
ssh-keygen -t rsa
Assign the pass phrase (press [enter] key twice if you don’t want a passphrase). It will create 2 files in ~/.ssh directory as follows:
- ~/.ssh/id_rsa : identification (private) key
- ~/.ssh/id_rsa.pub : public key
How to copy a public ley (~/.ssh/id_rsa.pub) to your server
Use the scp command to copy the id_rsa.pub (public key) from your local system to rh9linux.nixcraft.org remote server as authorized_keys file, this is know as, “installing the public key to server”:
Another option is to use the ssh-copy-id command as follows from your local workstation:
scp ~/.ssh/id_rsa.pub [email protected]:~/.ssh/authorized_keys
Another option is to use the ssh-copy-id command as follows from your local workstation:
ssh-copy-id user@remote-box
ssh-copy-id -i ~/.ssh/id_rsa.pub [email protected]
Freebsd Generate Ssh Host Key Changed
How to login to your remote server using SSH keys
From your local system (e.g. FreeBSD/macOS/Linux/Unix workstation) type the following command:
ssh user@remote-box
ssh [email protected]
Changing the pass-phrase on workstation
To change a passphrase for your ssh keys, use the ssh-keygen command as follows:
OR
ssh-keygen -p
OR
cd ~/.ssh/
ssh-keygen -f id_rsa -p
How to use ssh-agen command
You can use the ssh-agent command to avoid continues passphrase typing at the CLI:
Now ssh server will not use prompt for the password. Above two commands can be added to your ~/.bash_profile file so that as soon as you login into workstation you can set the agent.
ssh-agent $SHELL
ssh-add
Now ssh server will not use prompt for the password. Above two commands can be added to your ~/.bash_profile file so that as soon as you login into workstation you can set the agent.
Deleting the keys hold by ssh-agent
Generating A New Ssh Key
To list keys, enter:
To delete all keys, enter:
To remove specific key, enter:
ssh-add -l
To delete all keys, enter:
ssh-add -D
To remove specific key, enter:
ssh-add -d key
See also:
- Man pages: sshd(8),ssh(1),ssh-add(1),ssh-agent(1)
Create New Ssh Key
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