Public and private
SSH key pair can be used for public key authentication method in
SSH. A keypair could optionally be protected by a passphrase. If no passphrase is set on the public and private
SSH key pair, a public key authentication method could be used to automate remote command execution and file transfer.
You can create public and private
SSH key pair using the
ssh-keygen is normally bundled with
SSH client packages and is included in most
Linux distributions by default.
You can create an
SSH key pair by running
ssh-keygen at the terminal.
$ ssh-keygen Generating public/private rsa key pair.
ssh-keygen will generate a 2048 bit
rsa key pair if no option is specified. You can change the key's bit size and type by using
-t options respectively as the following example.
$ ssh-keygen -b 521 -t ecdsa
Possible values for key types are
Enter file in which to save the key (/home/user/.ssh/id_rsa):
Default location is in the
.ssh folder in your home directory and default filename is
Enter passphrase (empty for no passphrase): Enter same passphrase again:
Don't enter any passphrase if you want to use the key for passwordless
How to SSH without password
SSHkey pair will be created and saved in the location you previously specified.
Your identification has been saved in /home/user/.ssh/id_rsa. Your public key has been saved in /home/user/.ssh/id_rsa.pub.
The public key will have
.pub extension appended to the file name
SSHkey will be displayed for you to visually remember.
The key fingerprint is: SHA256:iiaD/fAzINYAP1MSUD3r0J9750Gpb1MMRvlERe2Yu+c [email protected] The key's randomart image is: +---[RSA 3072]----+ |.ooo o.oo. | |. . + o . .| |.. + o . o + | | .= o o.. o .| | o= . .S.oo . | |.+....o. o o . | |o.=.o ... .. . | | Bo . ..+. . .| | oo . +o. oE| +----[SHA256]-----+
$ ls -l ~/.ssh/id_rsa* -rw------- 1 user user 2590 Sep 29 11:22 /home/user/.ssh/id_rsa -rw-r--r-- 1 user user 563 Sep 29 11:22 /home/user/.ssh/id_rsa.pub
Note that the private key (
/home/user/.ssh/id_rsa) has a very strict permission where only the owner has read and write permission whereas group and other users doesn't have any permissions associated to them.
|Red Hat Enterprise Linux|
|SUSE Linux Enterprise Server|
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