Automate ssh-keygen -t rsa so it does not ask for a passphrase

Question

I need to automate ssh-keygen -t rsa with out a password i.e. enter at the prompt.
How can I do that from a shell script?

Answer 1

$ printf '\n' | ssh-keygen -N ''

Answer 2

I needed to automate in a bash script the ssh-keygen command and the final answer which works well to me:

echo -e "\n" | ssh-keygen -N "" &> /dev/null

The echo command with the -e interprets "\n" as an Enter key, but do not work with the passphrase. Then using the option -N "" (empty passphrase) the password will be empty and will not ask for anything. &> /dev/null will send the 'stdout' and 'stderr' to /dev/null so nothing is printed through the display.

Answer 3

What about :

ssh-keygen -q -t rsa -f ~/.ssh/id_rsa -N ''

As noted in man ssh-keygen :

SYNOPSIS
     ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa | rsa1] [-N new_passphrase] [-C comment] [-f output_keyfile]
(...)
      -q      Silence ssh-keygen.

(that is with openssh-client package in Debian 9.4 stretch : OpenSSH_6.7p1 Debian-5+deb8u4)

Answer 4

If you need to do this from PowerShell in windows use:

ssh-keygen -f $Name -t rsa -N '""'

note you also have to ensure the git bin directory is in your path:

$sshPath = "<path>\git\bin\"

$env:path += ";$sshPath"

Then to use it in PoshGit it's just:

Add-SshKey "<path>\.shh\KeyFilename"

Answer 5

Just a correction to answer 2... I found out on my OL and RHEL system the file name should be id_rsa not id.rsa.

So on a OL or RHEL system the command would be:

$ ssh-keygen -f id_rsa -t rsa -N ''

Answer 6

To generate a SSH keypair without being prompted for a passphrase you can do the following:

$ ssh-keygen -f id_rsa -t rsa -N ''