Ssh Generate Key Pair Authorized_keys

06.06.202006.06.2020

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A step-by-step guide for enabling EFS keystore access while OpenSSH Public Key Authentication is used

Ssh Authorized Keys File Location
Ssh Generate Authorized_keys

Mar 31, 2018 Generate public key and store into a file. It is a simple one liner command to generate a public key from a private key, so lets say our private key is named ‘user@myserver.key’ and we want to generate the public key and name it ‘authorizedkeys’. Below is the command to do this. Adding your SSH key to the ssh-agent. Before adding a new SSH key to the ssh-agent to manage your keys, you should have checked for existing SSH keys and generated a new SSH key. When adding your SSH key to the agent, use the default macOS ssh-add command, and not an application installed by macports, homebrew, or some other external source. SiteGround uses key-based authentication for SSH. This has proven more secure over standard username/password authentication. More information on SSH keys can be found here. You can generate an SSH key pair directly in cPanel, or you can generate the keys yourself and just upload the public one in cPanel to use with your hosting account.

May 05, 2019 Creating SSH keys with PuTTYgen # To generate an SSH key pair on Windows using PuTTYgen perform the following steps: Start the PuTTYgen tool, by double-clicking on its.exe file or going to the Windows Start menu → PuTTY (64-bit) → PuTTYgen. For “Type of key to generate. Generate Public/Private SSH Key Pair. 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. Documentation remote-access ssh passwordless Passwordless SSH access. It is possible to configure your Pi to allow your computer to access it without providing a password each time you try to connect. To do this you need to generate an SSH key: Check for existing SSH keys. The steps below will walk you through generating an SSH key and adding the public key to the server. Step 1: Check for SSH Keys. First, check for existing SSH keys on your computer. Open Git Bash, Cygwin, or Terminal, etc. And enter: $ ls -al /.ssh # Lists all the files in your.ssh directory, if they exist Generating public/private rsa key pair.

What is EFS?

In general, the Encrypted Files System (EFS) support on AIX enables individual users on the system to encrypt their data and also access it through keyed protection. Users will be able to setup keys and assign a default key for EFS. These keys are stored in cryptographically protected key store and upon successful login, the user's keys are loaded into the kernel and associated with the kernel processes.

Andrea - unfortunately you need TACs involvment since they can generate the support key and log into the CLI to clear the stuck downloads. Without TACs support, your only option to do deploy an updated VM and import a backup for the trial. Clearpass stuck at generate support keys 2017. I'm setting up a new Clearpass server and need the serial number to generate a license key. When I try to access Policy Manager via GUI, I get stuck at a license key entry page with no offline activation options (which differs from what the setup guide says). I never see an admin logon screen. 1) Generate password recovery key 2) Generate a support key 3) Generate password recovery and support keys Enter the option or press any key to quit: 4. To generate the recovery key, select option 1. To generate a support key and a recovery key and support, select option 3.

Private keys are associated to users and groups. These keys are stored in keystores and are protected by passwords. A user keystore contains the user's private key and also password to open the user's group keystores; the group keystores contain the groups' private keys.

When a process opens a keystore, either at user login time or using a specific EFS user command, the keys contained in this keystore (and related keystores) are loaded in the kernel and associated with the process credentials. Later on,when the process needs to open an EFS protected file, these credentials are tested. If a key matching the file protection is found, then the process is able to decrypt the file key and therefore the file content.

Keystore creation or opening can happen at login time, by the way of an EFS LAM (old) or PAM (new) module. These modules, as well as the commands (for example, chmod) make calls to some EFS APIs provided by a libefs.a library. Two user commands exist, efsmgr and efskeymgr, to give some control over EFS to the user and administrator.

How to setup Public Key Authentication in OpenSSH

Create a user on the client side and generate keys for this user. Public-private key pairs can be generated using the ssh-keygen command.

On the client side, go to /etc/ssh/ssh_config file and set PubkeyAuthentication yes.
On the server side, go to /etc/ssh/sshd_config file to set PubkeyAuthentication yes.
Configure OpenSSH server and client to use EFS logon while Public Key Authentication.
On the client side, go to /etc/ssh/ssh_config file and set 'AllowPKCS12keystoreAutoOpen yes'.
On the server side, go to /etc/ssh/sshd_config file and set 'AllowPKCS12keystoreAutoOpen yes'.
Restart the server:
Generate keys with the following command using a user created as follows:
The command ssh-keygen prompts for passphrase. This passphrase will be used to encrypt the private-key file on the client side. Adobe photoshop cs3 activation key generator. Even ssh-keygen command will accept the empty passphrase, in which case, private-key file will not be encrypted.
Copy the public keys on to the server in the file ~/.ssh/authorized_keys.

Similarly, any number of a Client user's public key can be copied in the file ~/.ssh/authorized_keys file on server user account.

AIX EFS Configurations

EFS has to be enabled on the server side using the efsenable command. This creates an admin keystore. The keystore gets created for a user in two cases.

Whenever a new user is created.
When passwd is assigned to the user or when user logs in.

The path where user keystore gets created on the system is /var/efs/users/<userlogin>/keystore.

The format of user keystore is in PKCS#12 which contains public and private objects. Private objects are protected by user access key. This user access key is nothing but a hash of a user-defined password (either login password or another password specific to EFS).

Public key cookie needs to be created and inserted into the keystore on server side. User invokes the efskeymgr command to insert the cookie. A public key cookie is the passwd encrypted with users public key.

The following steps show how to create a keystore for a user and insert the public key cookies.

When all the previous configuration setting are complete, run the ssh to log onto the remote machine using the public key authentication.

Run the following command to log on to the remote machine:

Once the connection is established and public key authentication is successful, the ssh server checks if AllowPKCS12keystoreAutoOpen is set to 'yes' in the sshd_config file. If so, it sends the ssh client a data packet.
The ssh client, on receiving this data packet, checks if the same option is enabled on the client side. That is, the ssh client is configured for this feature by checking if the AllowPKCS12keystoreAutoOpen is set to yes in the ssh_config file. If enabled, the client sends an acknowledgement to the server saying that it too supports this feature.
On receiving the ACK from the ssh client, the sshd opens the user's efs keystore in /var/efs/user/<username>/keystore and reads the publickey cookie SSHPub(AK) and sends it to ssh client.
The ssh client, on receiving the SSHPub from server, decrypts it with its private key and sends the accesskey(AK) back to server. With AK, sshd will open the user's private part of the user's keystore and call the EFS kernel extension to push this opened keystore into the kernel and associate it with the user's log on process.

Verify the authentication and EFS login

The OpenSSH client user ram is all set for Public Key authentication to user laxman on the OpenSSH server with EFS login. Verify the same with ssh login from client:

Applications for this setup

This setup can be used along with DB2 UDB DPF for which OpenSSH public key authentication can be used. The DB2 tables are encrypted using EFS.

Troubleshooting

Check if all the configurations listed above have been performed. Check if the public key cookie is inserted properly byefskeymgr command by verifying the keystore file size before and after the insertion. Enable debug for sshd and check if any failures. Also, verify once with password authentication if the account login and efs login succeed.

Downloadable resources

Generating a key pair and propagating the public key

Generating your key pair and propagating your public key is simpler than it sounds. Let’s walk through it.

Generating the key

The minimum effort to generate a key pair involves running the ssh-keygen command, and choosing the defaults at all the prompts:

Ssh Authorized Keys File Location

The default location to store the keys is in the ~/.ssh directory, which will be created if it does not exist:

Allowing this command to create the directory also ensures that the owner and permissions are set correctly. Some applications will not use keys if the permissions to the private key are too open.

The file ending in .pub is the public key that needs to be transferred to the remote systems. It is a file containing a single line: The protocol, the key, and an email used as an identifier. Options for the ssh-keygen command allow you to specify a different identifier:

After generating the key pair, the ssh-keygen command also displays the fingerprint and randomart image that are unique to this key. This information can be shared with other people who may need to verify your public key.

Later you can view these with:

The -l option lists the fingerprint, and the -v option adds the ASCII art.

Propagating the public key to a remote system

If password authentication is currently enabled, then the easiest way to transfer the public key to the remote host is with the ssh-copy-id command. If you used the default name for the key all you need to specify is the remote user and host:

Following the instructions from the output, verify that you can connect using the key pair. If you implemented a passphrase, you will be prompted for the passphrase to use the private key:

Examine the resulting authorized key file. This is where the public key was appended. If the directory or file did not exist, then it was (or they were) created with the correct ownership and permissions. Each line is a single authorized public key:

To revoke access for this key pair, remove the line for the public key.

There are many other options that can be added to this line in the authorized key file to control access. These options are usually used by administrators placing the public keys on a system with restrictions. These restrictions may include where the connection may originate, what command(s) may be run, and even a date indicating when to stop accepting this key. These and more options are listed in the sshd man page.

Changing the passphrase

If you need to change a passphrase on your private key or if you initially set an empty passphrase and want that protection at a later time, use the ssh-keygen command with the -p option:

You can add additional options to specify the key (-f), and the old (-P) or new (-N) passphrases on the command line. Remember that any passwords specified on the command line will be saved in your shell history.

See the ssh-keygen man page for additional options.

Rotating keys

While the public key by itself is meant to be shared, keep in mind that if someone obtains your private key, they can then use that to access all systems that have the public key. These key pairs also do not have a period of validity like GNU Privacy Guard (GPG) keys or public key infrastructure (PKI) certificates.

If you have any reason to suspect that a private key has been stolen or otherwise compromised, you should replace that key pair. The old public key has to be removed from all systems, a new key has to be generated with ssh-keygen, and the new public key has to be transferred to the desired remote systems.

If you are rotating keys as a precaution and without any concern of compromise, you can use the old key pair to authenticate the transfer of the new public key before removing the old key.

Is using empty passphrases ever a good idea?

There are several things to think about when considering an empty passphrase for your SSH private key.

How secure is the private key file?

If you tend to work from multiple client systems and want to either have multiple copies of your key or keep a copy on removable media, then it really is a good idea to have a passphrase on the private key. This practice is in addition to protecting access to the key file with encrypted media.

However, if you have only one copy of the private key and it is kept on a system that is well secured and not shared, then having a passphrase is simply one more level of protection just in case.

Remember that changing the passphrase on one copy does not change the passphrase on other copies. The passphrase is simply locking access to a specific key file.

Why do think you need an empty passphrase?

There are cases for keys with empty passphrases. Some utilities that need to automatically transfer files between systems need a passwordless method to authenticate. The kdump utility, when configured to dump the kernel to a remote system using SSH, is one example.

Another common use is to generate a key pair for a script that is designed to run unattended, such as from a cron job.

How about a middle ground alternative?

By itself, a passphrase-protected private key requires the passphrase to be entered each time the key is used. This setup does not feel like passwordless SSH. However, there are caching mechanisms that allow you to enter the key passphrase once and then use the key over and over without reentering that passphrase.

More Linux resources

OpenSSH comes with an ssh-agent daemon and an ssh-add utility to cache the unlocked private key. The GNOME desktop also has a keyring daemon that stores passwords and secrets but also implements an SSH agent.

The lifetime of the cached key can be configured with each of the agents or when the key is added. In many cases, it defaults to an unlimited lifetime, but the cache is cleared when the user logs out of the system. You will be prompted for the passphrase only once per login session.

If there is a scheduled application that needs to run outside of a user login session, it may be possible to use a secret or other password manager to automate the unlocking of the key. For example, Ansible Tower stores credentials in a secure database. This database includes an SSH private key used to connect to the remote systems (managed nodes), and any passphrases necessary for those private keys. Once those credentials are stored, a job can be scheduled to run a playbook on a regular schedule.

Automating propagation

A centralized identity manager such as FreeIPA can assist with key propagation. Upload the public key to the server as an attribute of a user account, and then propagate it to the hosts in the domain as needed. FreeIPA can also provide additional host-based access control for where a key may be used.

Keys can also be distributed using Ansible modules. The openssh_keypair module uses ssh-keygen to generate keys and the authorized_key module adds and removes SSH authorized keys for particular user accounts.

Wrapping up

SSH key pairs are only one way to automate authentication without passwords. Using the Generic Security Services Application Program Interface (GSSAPI) authentication is also common when trying to reduce the use of passwords on a network with centralized user management. SSH key pairs are the easier option to implement when single sign-on (SSO) is not already available.

Many source code repositories grant access using SSH keys. You can upload a public key to an account in the hosting organization such as the Fedora Account System, GitLab, or GitHub sites and use that key pair to authenticate when pulling and pushing content to repositories.

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