How to execute ssh-keygen without prompt

man ssh-keygen
ssh-keygen mac
ssh-keygen -t rsa
ssh-keygen user@host
ssh-rsa key generator
generate ssh key ubuntu
ssh keygen passphrase stdin
ssh-keygen with passphrase

I want to automate generate a pair of ssh key using shell script on Centos7, and I have tried

yes "y" | ssh-keygen -t rsa
echo "\n\n\n" | ssh-keygen...
echo | ssh-keygen..

all of these command doesn't work, just input one 'enter' and the shell script stopped on "Enter passphrase (empty for no passphrase)", I just want to know how to simulate mutiple 'enter' in shell continuously.

Many thanks if anyone can help !

Just use a void pass using -N flag:

ssh-keygen -t rsa -N ''

To overwrite the key file (in this example id_rsa):

 ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa 2>/dev/null <<< y >/dev/null

From ssh-keygen man page:

  -N new_passphrase provides the new passphrase.
  -q                silence ssh-keygen.
  -f filename       specifies the filename of the key file.

Step by step explanation

$ ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/home/klashxx/.ssh/id_rsa):

1) To avoid entering the key use -f:

$ ssh-keygen -t rsa -f ~/.ssh/id_rsa
Generating public/private rsa key pair.
/home/klashxx/.ssh/id_rsa already exists.
Overwrite (y/n)?

2) Now we need to answer "y" automatically to the overwrite question (let's use a here-string for that job):

$ ssh-keygen -t rsa -f ~/.ssh/id_rsa <<< y
Generating public/private rsa key pair.
/home/klashxx/.ssh/id_rsa already exists.
Overwrite (y/n)? Enter passphrase (empty for no passphrase):

3) Finally we're going to use the -N flag to enter a void pass:

$ ssh-keygen -t rsa -N '' -f ~/.ssh/id_rsa <<< y
Generating public/private rsa key pair.
/home/klashxx/.ssh/id_rsa already exists.
Overwrite (y/n)? Your identification has been saved in /home/klashxx/.ssh/id_rsa.
Your public key has been saved in /home/klashxx/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:Xo0t6caMB/8TSsigxfY28JIfqYjyqxRZrFrPncx5yiU klashxx@server
The key's randomart image is:
+---[RSA 2048]----+
|                 |
|  .              |
|   o .           |
|  +   *    =     |
| +.  + BSo= o    |
|...o.+o+XO...    |
|.. .o.E==+B. .   |
|o . ...=.o...    |
|.+o.  o     ..   |
+----[SHA256]-----+

4) Extra ball, cleanup the output, just check the return code:

$ ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa 2>/dev/null <<< y >/dev/null
$ echo $?
0

Kudos

@lukasz-dynowski, @redochka, @mellow-yellow and the rest of the folks in this thread.

Automate ssh-keygen -t rsa so it does not ask for a passphrase , To generate a SSH keypair without being prompted for a passphrase you can do the following: $ ssh-keygen -f id_rsa -t rsa -N ''. What you should do is utilize ssh-keygen(1) (see 'man ssh-keygen') and create a public and private key. Since you don't want a password prompt simply don't supply a password. You'll find the results in the .ssh directory of your home directory (~/.ssh).

If you don't want to prompt user for a file in which to save the key then, you can add file output flag -f to the command.

ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa

This way user will not be prompted for any input -unless id_rsa file(s) already exist.

Automated ssh-keygen without passphrase, how?, This will prevent the passphrase prompt from appearing and set the key-pair to be stored in plaintext (which of course carries all the disadvantages and risks of  On host_src, run this command as the user that runs scp/ssh/rsync $ ssh-keygen -t rsa. This will prompt for a passphrase. Just press the enter key. It'll then generate an identification (private key) and a public key. Do not ever share the private key with anyone!ssh-keygen shows where it saved the public key.

For me, i had to use combination of both @Lukasz answer and @Juan one, when using in ssh command

ssh -p$SSH_PORT -q joker@$INSTANCE_IP 'yes y | ssh-keygen -t rsa -N "" -f ~/.ssh/id_rsa'

Running ssh-keygen without human interaction?, You can do more or less anything with command-line arguments. Is there something particular you want to do which doesn't appear in the man page? cat /dev/zero | ssh-keygen -q -N "" If the ~/.ssh/id_rsa file already exists, the command will exit without modifying anything. If not, you get a brand new key, in that filename. Either way, you haven't overwritten anything, and you know at the end you have a key.

None of the answers do exactly what is expected. The wanted behavior: run ssh-keygen with default settings (like if we just spammed Enter) without ever prompting for input.

The command to run is:

yes '' | ssh-keygen -N >/dev/null

leave out the >/dev/null if you want to print output.

Expalaination: yes y spams y which ssh-keygen takes literally and makes the keys in $PWD/y and $PWD/y.pub . yes '' spams empty lines (Enter) which is what we want. Specifying the file with -f ~/.ssh/id_rsa fails if .ssh directory doesn't exist. The -t rsa option is not required if rsa is the default type (we're spamming enter anyways). The passphrase is not read from stdin (which we're spamming enters on) but from the keyboard directly so nothing can intercept it. For this reason you need to specify -N '' for empty passphrase.

How to use ssh-keygen to generate a new SSH key, You don't want to enter any passwords, because you want to call ssh from a within a First log in on A as user a and generate a pair of authentication keys. Launch the Settings app and click the “Apps” category. Next, click the “Manage optional features” link. If you don’t see “OpenSSH Client” in the list which appears, click the “Add a feature” button

Inside my Dockerfile (From node:8.13.0), the following works nicely: yes 'y' | /usr/bin/ssh-keygen

More complete example:

yes 'y' | /usr/bin/ssh-keygen -q -N '' -t rsa -f /etc/ssh/ssh_host_rsa_key && \
yes 'y' | /usr/bin/ssh-keygen -q -N '' -t dsa -f /etc/ssh/ssh_host_dsa_key

SSH login without password, It is designed for logging into and executing commands on a remote machine, as well as Using keys, SSH can authenticate you to all your computer accounts securely without the There are two files generated: one with and one without the .pub extension. SCP will prompt you for the password to the remote machine. To remotely execute a command from the local machine, append an instruction to the SSH command. For example, to delete a file, type in: ssh test.server.com rm ~/Desktop/Dir1/sample4. Enter the password, and the file on the remote server will be deleted without creating a new shell.

Linux, Run it on your server with no options, or arguments to generate a 2048-bit RSA key The default directory for SSH keys is ~/.ssh with the private key named id_rsa and it will prompt you to confirm before allowing you to save the private key. 2) SSh connection with Windows Powershell and command prompt. Now you can decide to use the command prompt or Windows PowerShell to access your Linux server via ssh. a) SSh with Windows Powershell. The Windows Powershell native tool allows you to remotely connect to a server via ssh. You just have to open it with Windows + r then hit the key A

The Guide to Generating and Uploading SSH Keys, cd /home/username/.ssh. Run ssh-keygen to generate an SSH key-pair. Run the following command in the .ssh folder. The program prompts you for the  I have installed four Redhat OS in VMWARE which is connected through IP. when i run script at host server with ssh-keygen, it always ask me for password. To resolved it i have also used sshpass and passing password from one temp file but same issue. each time it ask for password. I have follow all three steps of SSH-KEYGEN.

Creating SSH Keys (Command Line), In this article we show how you generate an SSH key on your local machine in order to log in to The command prompts you for a file to save the key in: For more information on how to run Linux on Windows, click here. # ssh-keygen -t rsa -b 4096 -C "root@localhost" Generating public/private rsa key pair. Enter file in which to save the key (/root/.ssh/id_rsa): Created directory '/root/.ssh'. Enter passphrase (empty for no passphrase): Enter same passphrase again: Your identification has been saved in /root/.ssh/id_rsa.

Comments
  • I have known this way, but I just want to use 'ssh-keygen -t rsa' to implement.
  • Then without the -N flag have any solutions?
  • You can use expect but seems to complicated when -N handle it nicely.
  • Just want to add in here that if you want to overwrite id_rsa, you need to append the -f flag to this answer. For me, this was creating a y and y.pub rsa key file pair. This code fixed it: yes y | ssh-keygen -q -t rsa -n '' -f ~/.ssh/id_rsa >/dev/null
  • @ingage: yes y | ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa >/dev/null Otherwise it asks passphrase