005. lap

WakeOnLan

WakeOnLan

sudo apt-get install wakeonlan
wakeonlan <MAC-ADDRESS>

ssh-keygen: password-less SSH login

SSH is often used to login from one system to another without requiring passwords.

ssh-keygen is used to generate that key pair for you. Here is a session where your own personal private/public key pair is created:

pzoli@debian7:~> ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (${home}/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in ${home}.ssh/id_rsa.
Your public key has been saved in ${home}/.ssh/id_rsa.pub.
The key fingerprint is:

The command ssh-keygen -t rsa initiated the creation of the key pair.

No passphrase was entered (Enter key was pressed instead).

The private key was saved in .ssh/id_rsa. This file is read-only and only for you. No one else must see the content of that file, as it is used to decrypt all correspondence encrypted with the public key.

The public key is save in .ssh/id_rsa.pub.

In this case, the content of file id_rsa.pub is

ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAIEArkwv9X8eTVK4F7pMlSt45pWoiakFkZMw
G9BjydOJPGH0RFNAy1QqIWBGWv7vS5K2tr+EEO+F8WL2Y/jK4ZkUoQgoi+n7DWQVOHsR
ijcS3LvtO+50Np4yjXYWJKh29JL6GHcp8o7+YKEyVUMB2CSDOP99eF9g5Q0d+1U2WVdB
xQM= rsa-key-${date}

It is one line in length.

Its content is then copied in file .ssh/authorized_keys of the system you wish to SSH to without being prompted for a password.

The example shown here generated keys on sodium by user cantin. If the public key generated, file .ssh/id_rsa.pub, was copied to your account, file .ssh/authorized_keys on remote, then user is allowed to SSH into your own account on remote without the use of a password.

To summarize, a personal private/public key pair is generated using the ssh-keygen command. The public key is then copied onto a remote systems' .ssh/authorized_keys file.

cat $HOME/.ssh/id_rsa.pub >> $HOME/.ssh/authorized_keys

And you can now SSH to the remote systems's account without the use of a password.

Connect with windows scp, ssh

PuttyGen.exe
SSH2-RSA Generate
empty passphrase
Save Public key
Save Private key
save to clipboard Public key for passing into OpenSSH authorized_keys file:
 
ssh-rsa *..*== rsa-key-${date}
 
past clipboard to remote $HOME/.ssh/${host}-openssh-authorized_keys.pub
remote server:
cd $HOME/.ssh/
cat ${host}-openssh-authorized_keys.pub >>authorized_keys

Ubuntu release info

lsb_release -a