Ssh Rsa Private Key

Posted : admin On 1/29/2022

My Git setup runs fine on Linux, but when I try to set things up under Windows (using Git for Windows and TortoiseGit), I don't know where to put my private SSH key (or, better still, how to tell ssh. Azure currently supports SSH protocol 2 (SSH-2) RSA public-private key pairs with a minimum length of 2048 bits. Other key formats such as ED25519 and ECDSA are not supported. Create an SSH key pair Use the ssh-keygen command to generate SSH public and private key files.

  1. Ssh Rsa Private Key Format
  2. Ssh Rsa Private Key List
  3. Ssh With Rsa Key

Log in with an SSH private key on Linux and macOS

Authored by: Brint Ohearn

This article demonstrates how to use a private key to log in to a Linux®server by using a private key with a Terminal session on macOS®. However,you can follow the same process to use a private key when using anyterminal software on Linux.

The private key (identification) is now located in /home/ demo /.ssh/idrsa. Step Three—Copy the Public Key Once the key pair is generated, it’s time to place the public key on the server that we want to use. The other method is to password-protect your private key so that you are prompted for the password when authenticating (think two-factor authentication using both the private key and the password). Ssh-keygen without a password. To generate an SSH key pair, use the following command: [email protected] $ ssh-keygen Generating public/private rsa key pair. If the installed ssh uses the AES-128-CBC cipher, RXA cannot fetch the private key from the file. RSA key-based authentication does not work. To support RSA key-based authentication, take one of the following actions: Install an ssh that uses the DES-EDE3-CBC cipher.

Note: For information about using Secure Shell (SSH) private keys on Microsoft®Windows® operating systems, seeLogging in with an SSH Private Key on Windowsand Generate RSA keys with SSH by using PuTTYgen.

Prerequisites

To complete this process, you need the following software applications:

  • SSH client software that is installed on your Linux or macOS operating system by default.
  • Your favorite text editor. This example uses the vim text editor.
  • Your private key. For more information about generating a key on Linux or macOS, seeConnect to a server by using SSH on Linux or Mac OS X.

Log in with a private key

  1. Using a text editor, create a file in which to store your private key. This example usesthe file deployment_key.txt.

  2. To edit the file in vim, type the following command:

  3. After the editor starts, press i to turn on insert mode.

  4. Paste your private key, such as the one in the following image, into the file.Be sure to include the BEGIN and END lines.

  5. To save your changes, press Esc.

  6. Type :wq to write the file and return to the command line.

  7. Run the following command to change the file permissions to 600 to secure the key. You can also set them to 400.This step is required:

  8. Use the key to log in to the SSH client as shown in the following example, which loads the key in file deployment_key.txt, and logs in as user demo to IP 192.237.248.66:

  9. When you are prompted to confirm the connection, type yes and then press Enter.

  10. If your SSH key requires a password, enter it when prompted to complete the connection.

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It is possible to configure your Raspberry Pi to allow access from another computer without needing to provide a password each time you connect. To do this, you need to use an SSH key instead of a password. To generate an SSH key:

Check for existing SSH keys

First, check whether there are already keys on the computer you are using to connect to the Raspberry Pi:

If you see files named id_rsa.pub or id_dsa.pub then you have keys set up already, so you can skip the 'Generate new SSH keys' step below.

Generate new SSH keys

To generate new SSH keys enter the following command:

Ssh

Upon entering this command, you will be asked where to save the key. We suggest saving it in the default location (~/.ssh/id_rsa) by pressing Enter.

You will also be asked to enter a passphrase, which is optional. The passphrase is used to encrypt the private SSH key, so that if someone else copied the key, they could not impersonate you to gain access. If you choose to use a passphrase, type it here and press Enter, then type it again when prompted. Leave the field empty for no passphrase.

Now look inside your .ssh directory:

and you should see the files id_rsa and id_rsa.pub:

The id_rsa file is your private key. Keep this on your computer.

Ssh Rsa Private Key Format

The id_rsa.pub file is your public key. This is what you share with machines that you connect to: in this case your Raspberry Pi. When the machine you try to connect to matches up your public and private key, it will allow you to connect.

Take a look at your public key to see what it looks like:

It should be in the form:

Key

Copy your public key to your Raspberry Pi

Using the computer which you will be connecting from, append the public key to your authorized_keys file on the Raspberry Pi by sending it over SSH:

Note that for this step you will need to authenticate with your password.

Alternatively, if ssh-copy-id is not available on your system, you can copy the file manually over SSH:

If you see the message ssh: connect to host <IP-ADDRESS> port 22: Connection refused and you know the IP-ADDRESS is correct, then you may not have enabled SSH on your Raspberry Pi. Run sudo raspi-config in the Pi's terminal window, enable SSH, then try to copy the files again.

Now try ssh <USER>@<IP-ADDRESS> and you should connect without a password prompt.

If you see a message 'Agent admitted failure to sign using the key' then add your RSA or DSA identities to the authentication agent ssh-agent then execute the following command:

If this does not work, you can get assistance on the Raspberry Pi forums.

Note: you can also send files over SSH using the scp command (secure copy). See the SCP guide for more information.

Ssh Rsa Private Key List

Adjust permissions for your home and .ssh directories

If you can't establish a connection after following the steps above there might be a problem with your directory permissions. First, you want to check the logs for any errors:

If the log says Authentication refused: bad ownership or modes for directory /home/pi there is a permission problem regarding your home directory. SSH needs your home and ~/.ssh directory to not have group write access. You can adjust the permissions using chmod:

Now only the user itself has access to .ssh and .ssh/authorized_keys in which the public keys of your remote machines are stored.

Store the passphrase in the macOS keychain

If you are using macOS, and after verifying that your new key allows you to connect, you have the option of storing the passphrase for your key in the macOS keychain. This allows you to connect to your Raspberry Pi without entering the passphrase.

Ssh With Rsa Key

Run the following command to store it in your keychain: