1. Ssh Key Generation Linux
2. Git Add Ssh Key
3. How To Generate Ssh Key Pair
4. Ssh Key Generation Mac
5. What Is Ssh Key Generation
6. What Is Ssh Key Generation 10
7. What Is Ssh Key Generation 3

Updated on March 30, 2020

Spend enough time in an IT environment and you will likely come across the term SSH keys. If you’ve already come across this IT term, then you might find yourself wondering, what are SSH keys? SSH (Secure Shell) keys are an access credential that is used in the SSH protocol.

This article explains how to generate CSR/Private Key pair using the command line interface on a Linux operating system. You will need an SSH client on your local computer if accessing via SSH, something like Putty (for windows) or the Terminal on a linux or mac computer. The public key, however, is meant to be saved on the servers you intend to access, in the “/.ssh/authorizedkeys” file (or rather, pasted/added to this file). To open this key, to copy, and then paste, wherever necessary, enter the following in Command Prompt.

Read the rest of this post to learn more about what are SSH keys or consider watching webinar below to find out more about the SSH protocol and the basics of SSH authentication.

Before this post delves into an explanation on what are SSH keys, let’s take a quick look at the SSH protocol.

The SSH Protocol

The first version of the SSH protocol was developed in the summer of 1995 by Tatu Ylonen. Tatu was a researcher at the University of Helsinki when a sniffing attack was discovered on the university network. A sniffing attack intercepts and logs the traffic that takes place on a network, and can provide attackers with usernames and passwords which can then be used to gain access to critical IT assets. Thousands of credentials were impacted, including those belonging to community partnerships. This sniffing attack motivated Tatu to figure out how to make networks more secure, and this ultimately led to the creation of the SSH protocol (SSH.com).

Today, the SSH protocol is widely used to login remotely from one system into another, and its strong encryption makes it ideal to carry out tasks such as issuing remote commands and remotely managing network infrastructure and other vital system components. To use the SSH protocol, a couple pieces of software need to be installed. The remote systems need to have a piece of software called an SSH daemon, and the system used to issue commands and manage the remote servers needs to have a piece of software called the SSH client. These pieces of software are necessary to create a proper communication channel using the SSH protocol (DigitalOcean).

Essentially, SSH keys are an authentication method used to gain access to this encrypted connection between systems.

What are SSH keys?

SSH keys come in many sizes, but a popular choice is RSA 2048-bit encryption, which is comparative to a 617 digit long password. On Windows systems, it is possible to generate your own SSH key pair by downloading and using an SSH client like PuTTY. On Mac® and Linux® systems, it is possible to generate an SSH key pair using a terminal window. Watch the video below to find out how to generate your own RSA key pair on Mac and Linux. Rails generate custom secret key.

SSH keys always come in pairs, and each pair is made up of a private key and a public key. Who or what possesses these keys determines the type of SSH key pair. If the private key and the public key remain with the user, this set of SSH keys is referred to as user keys. If the private and public key are on a remote system, then this key pair is referred to as host keys. Another type of SSH key is a session key. When a large amount of data is being transmitted, session keys are used to encrypt this information.

Now let’s take a closer look at how a private key and public key work. To keep things simple, we will focus on how user keys work.

How User Keys Work

In a user key set, the private key remains on the system being used to access the remote system and is used to decrypt information that is exchanged in the SSH protocol. Private keys should never be shared with anyone. A public key is used to encrypt information, can be shared, and is used by the user and the remote server. On the server end, the public key is saved in a file that contains a list of authorized public keys. On the user’s side, the public SSH key is stored in an SSH key management software or in a file on their computer.

Ssh Key Generation Linux

Using SSH Keys

First Steps

Before you can start using SSH keys, first you need to generate your own SSH key pair on the system you would like to use to access a remote system. This article and the video mentioned above are great resources that can guide you through on how to generate an SSH key pair. Once the key pair is generated, the next step is to put the public SSH key on the remote server. Depending on your setup, this can be done by entering a couple commands in the terminal window, using JumpCloud, or by manually placing the public SSH key on the remote server (DigitalOcean).

Behind the Scenes of SSH Key Authentication

After completing the steps mentioned above, use your terminal to enter in your ssh username and the IP address of the remote system in this format: ssh username@my_ip_address. This will initiate a connection to the remote system using the SSH protocol. The protocol and specified username will then tell the remote server which public key to use to authenticate you. Then the remote server will use that public key to encrypt a random challenge message that is sent back to the client. This challenge message is decrypted using the private key on your system. Once the message is decrypted, it is combined with a previously arranged session ID and then sent back to the server. If the message matches with what the server sent out, the client is authenticated, and you will gain access to the remote server. This process proves to the server that you have the corresponding private key to the public key it has on file.

However, the security that this authentication process provides can be undermined when SSH keys are not properly managed.

Managing SSH Keys

It is imperative that proper SSH key management is in place because they often grant access to mission-critical digital assets. Also, companies tend to have a lot of SSH keys. In fact, Fortune 500 companies will often have several millions of these. Despite the difficulty in trying to manually manage millions of SSH keys, having an SSH key management system in place is continuously overlooked. SSH.com did some digging and discovered a company that had 3 million SSH keys “that granted access to live production servers. Of those, 90% were no longer used. Root access was granted by 10% of the keys, ” (SSH.com). An effective SSH key management system in place would have gone a long way in reducing this concerning security risk.

IT has a couple options to gain control over SSH keys in their environment. One of these includes using an SSH key management tool. However, this means having to manage one more platform in addition to managing an SSO provider, a directory service, and maybe a system management solution. A new solution has emerged that is providing IT with a second option: Directory-as-a-Service®.

Cloud IAM offers SSH Key Management

This cloud-based identity and access management (IAM) solution provides IT with one central place to manage SSH keys. Furthermore, IT can also centralize user authentication to Mac, Linux, and Windows systems, cloud servers, wired and WiFi networks, web-based and on-prem applications, and virtual and on-prem storage. With one central place to manage a user’s authentication to all of their resources, it becomes a simple matter of a few clicks to deprovision users from all of their resources, including SSH key access to remote systems.

Git Add Ssh Key

Learn More about SSH Key Management with JumpCloud

How To Generate Ssh Key Pair

For more information, consider reading this support article on how JumpCloud assists with SSH key management, or exploring this guide for a modern approach to managing user accounts on your cloud servers.
You are also more than welcome to reach out to us if you would like more information on how DaaS can simplify your SSH key management. If you’re ready to start testing our modern IAM platform, sign up for a free account. You’ll be able to explore all of our features, and your first ten users are free forever.

ssh-keygen is a standard component of the Secure Shell (SSH) protocol suite found on Unix, Unix-like and Microsoft Windows computer systems used to establish secure shell sessions between remote computers over insecure networks, through the use of various cryptographic techniques. The ssh-keygen utility is used to generate, manage, and convert authentication keys.

Overview[edit]

Ssh Key Generation Mac

ssh-keygen is able to generate a key using one of three different digital signature algorithms. With the help of the ssh-keygen tool, a user can create passphrase keys for any of these key types (to provide for unattended operation, the passphrase can be left empty, at increased risk). These keys differ from keys used by the related tool GNU Privacy Guard.

OpenSSH-based client and server programs have been included in Windows 10 since version 1803. The SSH client and key agent are enabled and available by default and the SSH server is an optional Feature-on-Demand.^[1][2]

Key formats supported[edit]

Originally, with SSH protocol version 1 (now deprecated) only the RSA algorithm was supported. As of 2016, RSA is still considered strong, but the recommended key length has increased over time.

The SSH protocol version 2 additionally introduced support for the DSA algorithm. As the DSA algorithm has ties to the American National Security Agency (NSA), aspects of its security have been called into question by Edward Snowden's global surveillance disclosures, particularly in light of the Bullrun decryption program.

Subsequently, OpenSSH added support for a third digital signature algorithm, ECDSA (this key format no longer uses the previous PEM file format for private keys, nor does it depend upon the OpenSSL library to provide the cryptographic implementation).

A fourth format is supported using ed25519, originally developed by independent cryptography researcher Daniel J. Bernstein.

ssh-keygen command syntax[edit]

The syntax of the ssh-keygen command is as follows:

Some important options of the ssh-keygen command are as follows:

Files used by the ssh-keygen utility[edit]

The ssh-keygen utility uses various files for storing public and private keys. The files used by ssh-keygen utility are as follows:

• $HOME/.ssh/identity: The $HOME/.ssh/identity file contains the RSA private key when using the SSH protocol version 1.
• $HOME/.ssh/identity.pub: The $HOME/.ssh/identity.pub file contains the RSA public key for authentication when you are using the SSH protocol version 1. A user should copy its contents in the $HOME/.ssh/authorized_keys file of the remote system where a user wants to log in using RSA authentication.
• $HOME/.ssh/id_dsa: The $HOME/.ssh/id_dsa file contains the protocol version 2 DSA authentication identity of the user.
• $HOME/.ssh/id_dsa.pub: The $HOME/.ssh/id_dsa.pub file contains the DSA public key for authentication when you are using the SSH protocol version 2. A user should copy its contents in the $HOME/.ssh/authorized_keys file of the remote system where a user wants to log in using DSA authentication.
• $HOME/.ssh/id_rsa: The $HOME/.ssh/id_rsa file contains the protocol version 2 RSA authentication identity of the user. This file should not be readable by anyone but the user.
• $HOME/.ssh/id_rsa.pub: The $HOME/.ssh/id_rsa.pub file contains the protocol version 2 RSA public key for authentication. The contents of this file should be added to $HOME/.ssh/authorized_keys on all computers where a user wishes to log in using public key authentication.

References[edit]

1. ^https://devblogs.microsoft.com/commandline/windows10v1803/
2. ^https://devblogs.microsoft.com/powershell/using-the-openssh-beta-in-windows-10-fall-creators-update-and-windows-server-1709/

External links[edit]

What Is Ssh Key Generation

What Is Ssh Key Generation 10

• Generating an SSH key, a guide from GitHub
• ssh-keygen manual from the OpenBSD project
• Linux man page from die.net

What Is Ssh Key Generation 3