Description

This article describes how to log in or copy a file to a Junos OS EX series switch using SSH public/private keys instead of a password. The command ssh-keygen is used to generate a public-private key pair. Then the public key is loaded into a remote authorized_keys file so that the files can be safely and securely copied to a remote server.

Symptoms

User wants to log in or copy a file to a Junos OS EX series switch using SSH public/private keys instead of a password

Solution


To create or generate a public/private ssh-keygen key pair, run the following commands:

root# run start shell
root@:RE:0% ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/root/.ssh/id_rsa):
/root/.ssh/id_rsa already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Passphrases do not match. Try again.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /root/.ssh/id_rsa.
Your public key has been saved in /root/.ssh/id_rsa.pub.
The key fingerprint is:
29:5e:3d:c9:4c:e1:d2:42:a9:78:a6:e4:a6:b9:df:f1 root@
The key's randomart image is:
+--[ RSA 2048]----+
| ... |
| ..o . |
| . .o + |
| o + O . |
| o +. S * |
| +. o . |
| + o |
| o . o |
| .o. . E |
+-----------------+
root@:RE:0% cd /root/.ssh/
root@:RE:0% cat id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC6bOKd6NLHnb7jvK6dQDo6fug+eQA46
ZDEGFRCNYbR2uFv9qUSJTp91fr4GgrSPkAeG3qlsG+fHxnQ+rRYEhphVf10ovdGQ5ShPi
W9+rsmaS83AlcIDEw7jy8JkVpO5rfho/SMaDldnurBYoaVW8I+jX1msdojsoktn1S1CQM
oWcedlm7SKjdJVg3YexC7JgBiizt3fScfzrG0p73MOwo4O5ex9a5hf5w7rXII/6IEBw3m
GgQo1jFgWXt1DqNm5iujTslEnqjAmguG7zuVmkcHEhyyIcmhCX+kbfU9+QHOvmgoTPuc/
SmaEGzCJaOyE53KxeM+5Xy7kSRoKbXsodg1 root@    <<< This is all one line.

Copy the contents of the id_rsa.pub public key on the client to the authorized_keys file on the server.

login as: root
[email protected]'s password:
--- JUNOS 12.3R2.5 built 2013-03-22 17:10:33 UTC
root@SWITCH:RE:0% pwd
/var/root
root@SWITCH:RE:0% cd /var/root/.ssh
root@SWITCH:RE:0% echo "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC6bOKd6N
LHnb7jvK6dQDo6fug+eQA46ZDEGFRCNYbR2uFv9qUSJTp91fr4GgrSPkAeG3qlsG+fHxnQ
+rRYEhphVf10ovdGQ5ShPiW9+rsmaS83AlcIDEw7jy8JkVpO5rfho/SMaDldnurBYoaVW8
I+jX1msdojsoktn1S1CQMoWcedlm7SKjdJVg3YexC7JgBiizt3fScfzrG0p73MOwo4O5ex
9a5hf5w7rXII/6IEBw3mGgQo1jFgWXt1DqNm5iujTslEnqjAmguG7zuVmkcHEhyyIcmhCX
+kbfU9+QHOvmgoTPuc/SmaEGzCJaOyE53KxeM+5Xy7kSRoKbXsodg1 root@ " >> authorized_keys

User can now log in to the switch without entering any password.

root@:RE:0% ssh 10.9.221.46
--- JUNOS 12.3R2.5 built 2013-03-22 17:10:33 UTC
root@SWITCH:RE:0%