Ssh Public Private Key

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Using a set of public/private keys to allow you to log into a remote Linux system or run commands using ssh without a password can be very convenient, but setup is just tad tricky.

  1. Ssh Public Private Key Generation
  2. Ssh Public Private Keys Explained
  3. Ssh Key Example
  4. Linux Generate New Ssh Public Private Key Pair
  5. Ssh Public Private Key Authentication
  6. Ssh Public Private Key Explained
  1. How to Generate an SSH Key. The first step to setting up an SSH key is to generate a pair. An SSH-key pair contains a public and private key. Using the public and private pair, you can authenticate a user to a remote host. In Linux, use the following command to generate an SSH key pair.
  2. May 05, 2020 SSH stands for Secure Shell and is a method used to establish a secure connection between two computers. SSH works by authenticating based on a key pair, with a private key being on a remote server and the corresponding public key on a local machine. When the keys match, access is granted to the remote user.
  3. The key-based authentication mechanism in SSH is called public key authentication. Essentially, some session-specific data is signed using the private identity key. The signature is then sent to the server that checks if the key used for signing is configured as an authorized key.
  4. SSH stands for Secure Shell and is a method used to establish a secure connection between two computers. SSH works by authenticating based on a key pair, with a private key being on a remote server and the corresponding public key on a local machine. When the keys match, access is granted to the remote user.

On Windows, you can create SSH keys in many ways. This document explains how to use two SSH applications, PuTTY and Git Bash.

Joyent recommends RSA keys because the node-manta CLI programs work with RSA keys both locally and with the ssh agent. DSA keys will work only if the private key is on the same system as the CLI, and not password-protected.

PuTTY

PuTTY is an SSH client for Windows. You can use PuTTY to generate SSH keys. PuTTY is a free open-source terminal emulator that functions much like the Terminal application in macOS in a Windows environment. This section shows you how to manually generate and upload an SSH key when working with PuTTY in the Windows environment.

About PuTTY

Public

PuTTY is an SSH client for Windows that you will use to generate your SSH keys. You can download PuTTY from www.chiark.greenend.org.uk.

When you install the PuTTY client, you also install the PuTTYgen utility. PuTTYgen is what you will use to generate your SSH key for a Windows VM.

This page gives you basic information about using PuTTY and PuTTYgen to log in to your provisioned machine. For more information on PuTTY, see the PuTTY documentation

Generating an SSH key

To generate an SSH key with PuTTYgen, follow these steps:

  1. Open the PuTTYgen program.
  2. For Type of key to generate, select SSH-2 RSA.
  3. Click the Generate button.
  4. Move your mouse in the area below the progress bar. When the progress bar is full, PuTTYgen generates your key pair.
  5. Type a passphrase in the Key passphrase field. Type the same passphrase in the Confirm passphrase field. You can use a key without a passphrase, but this is not recommended.
  6. Click the Save private key button to save the private key. You must save the private key. You will need it to connect to your machine.
  7. Right-click in the text field labeled Public key for pasting into OpenSSH authorized_keys file and choose Select All.
  8. Right-click again in the same text field and choose Copy.

Ssh Public Private Key Generation

Importing your SSH key

Now you must import the copied SSH key to the portal.

  1. After you copy the SSH key to the clipboard, return to your account page.
  2. Choose to Import Public Key and paste your SSH key into the Public Key field.
  3. In the Key Name field, provide a name for the key. Note: although providing a key name is optional, it is a best practice for ease of managing multiple SSH keys.
  4. Add the key. It will now appear in your table of keys under SSH.

PuTTY and OpenSSH use different formats of public SSH keys. If the text you pasted in the SSH Key starts with —— BEGIN SSH2 PUBLIC KEY, it is in the wrong format. Be sure to follow the instructions carefully. Your key should start with ssh-rsa AAAA….

Once you upload your SSH key to the portal, you can connect to your virtual machine from Windows through a PuTTY session.

Git Bash

The Git installation package comes with SSH. Using Git Bash, which is the Git command line tool, you can generate SSH key pairs. Git Bash has an SSH client that enables you to connect to and interact with Triton containers on Windows.

To install Git:

  1. (Download and initiate the Git installer](https://git-scm.com/download/win).
  2. When prompted, accept the default components by clicking Next.
  3. Choose the default text editor. If you have Notepad++ installed, select Notepad++ and click Next.
  4. Select to Use Git from the Windows Command Prompt and click Next.
  5. Select to Use OpenSSL library and click Next.
  6. Select to Checkout Windows-style, commit Unix-style line endings and click Next.
  7. Select to Use MinTTY (The default terminal of mYSYS2) and click Next.
  8. Accept the default extra option configuration by clicking Install.

When the installation completes, you may need to restart Windows.

Launching GitBash

To open Git Bash, we recommend launching the application from the Windows command prompt:

  1. In Windows, press Start+R to launch the Run dialog.
  2. Type C:Program FilesGitbinbash.exe and press Enter.

Generating SSH keys

First, create the SSH directory and then generate the SSH key pair.

One assumption is that the Windows profile you are using is set up with administrative privileges. Given this, you will be creating the SSH directory at the root of your profile, for example:

  1. At the Git Bash command line, change into your root directory and type.

  1. Change into the .ssh directory C:Usersjoetest.ssh

  2. To create the keys, type:
  1. When prompted for a password, type apassword to complete the process. When finished, the output looks similar to:

Uploading an SSH key

To upload the public SSH key to your Triton account:

  1. Open Triton Service portal, select Account to open the Account Summary page.
  2. From the SSH section, select Import Public Key.
  3. Enter a Key Name. Although naming a key is optional, labels are a best practice for managing multiple SSH keys.
  4. Add your public SSH key.

When Triton finishes the adding or uploading process, the public SSH key appears in the list of SSH keys.

What are my next steps?

  • Adding SSH keys to agent.
  • Set up the Triton CLI and CloudAPI on Windows.
  • Set up the Triton CLI and CloudAPI.
  • Create an instance in the Triton Service Portal.
  • Set up the triton-docker command line tool.
  • Visit PuTTYgen to learn more about the PuTTYgen and to seethe complete installation and usage guide.

This tutorial explains the Passwordless SSH using Public Key and Private Key in Linux.

SSH stands for Secure SHELL, is a protocol used to connect remote hosts to login or performing some tasks using scripts.

When we want to automate some tasks on remote hosts using scripts from a centralized server like Jenkins/Ansible or any Linux Server, we may require a password less connection between the remote hosts and the centralized Server.

In this tutorial, we will learn to create Passwordless SSH login using public key and private key. Follow the step by step guide to make your ssh connection passwordless.

This tutorial will work for Linux Destro such as Centos, Ubuntu, Redhat, Amazon Linux(AWS EC2) and Other as well.

Recommended Read:How to Install Jenkins on Ubuntu

Also Read : Git Tutorial for beginners (Part I)

Scenario

We have one Local Machine and one Remote Server.We will setup a passwordless connection to login Remote Server from the local Machine.

Perform following steps on the remote Server

Step 1– Create an User and login or login as an existing user.

$ useradd devops

$ su – devops

Step 2 – Generate a key pair ( Public key and Private Key) using ssh-keygen command.

Before running this command make sure you are on home directory of the user.If not you can go to the home directory by cd ~ command.

$ cd ~

$ ssh-keygen -t rsa

It will ask for some details. Do not put anything here and press ENTER only.

By ls -al command you can see a hidden directory .ssh and two files namely id_rsa and id_rsa.pub inside .ssh directory are created.Here id_rsa is the Private key and id_rsa.pub is the Public Key.

Private key(id_rsa) is kept at source computer(local machine) from where you have to ssh. Public Key(id_rsa) is kept at Destination Server(Remote Server) , the Server you want to access.

Step 3- Create a file name authorized_keys in side .ssh directory and copy the content of id_rsa.pub file to authorized_keys file.

Go to .ssh directory

$ cd ~/.ssh/

Create an empty file name authorized_keys

Ssh Public Private Keys Explained

$ touch authorized_keys

Copy the content of id_rsa.pub to authorized_keys

$ cat id_rsa.pub > authorized_keys

Check the authorized_keys file if contents are copied.

$cat authorized_keys

Step 4 – Change the permission of authorized_keys

$ chmod 600 authorized_keys

Step 5– Copy the content of id_rsa file

Use cat command to display the content of id_rsa and copy its content.

$ cat id_rsa

On the local Machine

Step 1– Create a file and paste the content of id_rsa copied from remote server inside this file. You can use nano command to perform this action.

Create a file name devops.key using nano command , paste the content and pres Ctrl+X to save and close the file.

Ssh Key Example

$ nano devopys.key

Step 2 – SSH remote Server from local machine without using password.

Linux Generate New Ssh Public Private Key Pair

$ sudo ssh -i path-to-private-key [email protected]

$ sudo ssh -i devops.key [email protected]

Ssh Public Private Key Authentication

I hope you enjoyed this tutorial and learned Passwordless SSH login using public key and private key. If you think this is really helpful, please do share this to other as well. Please also share your valuable feedback, comment or any query in the comment box.I will really happy to resolve your all queries.

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