FAQs
SSH passphrases protect your private key from being used by someone who doesn't know the passphrase. Without a passphrase, anyone who gains access to your computer has the potential to copy your private key. For example, family members, coworkers, system administrators, and hostile actors could gain access.
How do I check my SSH passphrase? ›
In Keychain Access, search for SSH. In the lower-left corner, select Show password.
How to read existing SSH key? ›
Checking of existing SSH keys
- Whether you use macOS or Linux, open your Terminal application.
- Run cd ~/. ssh/ in your Terminal.
- If the folder exists, run ls and check if a pair of key exists : id_ed25519 and id_ed25519. pub. Using id_rsa and id_rsa. pub is fine too. We are just advocating the use of ed25519.
With SSH keys, if someone gains access to your computer, the attacker can gain access to every system that uses that key. To add an extra layer of security, you can add a passphrase to your SSH key. To avoid entering the passphrase every time you connect, you can securely save your passphrase in the SSH agent.
How do I know what SSH key I am using? ›
Checking for existing SSH keys
- Open Terminal .
- Enter ls -al ~/.ssh to see if existing SSH keys are present. $ ls -al ~/.ssh # Lists the files in your .ssh directory, if they exist.
- Check the directory listing to see if you already have a public SSH key. ...
- Either generate a new SSH key or upload an existing key.
- A passphrase for an SSH key is an additional layer of security that you can add to your private key. ...
- For example,
- :~# ssh-keygen.
- Generating public/private rsa key pair.
- Enter file in which to save the key (/root/.ssh/id_rsa):
- Enter passphrase (empty for no passphrase):
- Enter same passphrase again:
Protecting SSH keys
Passphrases are commonly used for keys belonging to interactive users. Their use is strongly recommended to reduce risk of keys accidentally leaking from, e.g., backups or decommissioned disk drives. In practice, however, most SSH keys are without a passphrase.
How do I view the contents of a SSH key? ›
The first method is to use the cat command:
- Using the run command.
- Execute the following command. cat ~/.ssh/id_rsa.pub. The command will display your SSH key on your Linux machine without requiring your key authentication password.
You can run the ssh-keygen utility on your local machine to generate an SSH key-value pair. The ssh-keygen utility generates a pair comprising of a public key and private key.
How to read SSH key in Windows? ›
For Windows 10 & 11
- Press the Windows key or open up the Start Menu. Type “cmd”.
- Under “Best Match”, click “Command Prompt”.
- In the command prompt, use the ssh-keygen command: ...
- The system will now generate the key pair and display the key fingerprint and a randomart image. ...
- Open your file explorer.
The passphrase chosen at account request time is specific to the private key file, not your user account! If you have forgotten this passphrase, there is no way to reset it, and you will have to generate a new SSH key pair. and follow the instructions to generate your new SSH key pair.
Is a SSH passphrase necessary? ›
SSH uses private/public key pairs to protect your communication with the server. SSH passphrases protect your private key from being used by someone who doesn't know the passphrase. Without a passphrase, anyone who gains access to your computer has the potential to copy your private key.
What is an example of a passphrase? ›
You can think of a passphrase as a short sentence that's at least 15 characters in length and consists of four or more words. By contrast, a password is usually shorter and more complicated. An example of a passphrase can be VirusOrMalwareMyDefenseIsRed.
How to see active keys in SSH? ›
Running ssh-add -l will display all keys currently known to your agent. If the list is empty, you have an ssh-agent running, but no keys currently unlocked. If you receive an error message like Could not open a connection to your authentication agent.
How do I know if my SSH key has a password? ›
The easiest way in this case is to run some operation on them using ssh-keygen . If it will ask for a passphrase, it has one (or it is not a ssh key), if not it does not have a passphrase: $ ssh-keygen -yf rsa_enc Enter passphrase: $ ssh-keygen -yf rsa ssh-rsa AAAAB3NzaC1y...
How do I specify which SSH key to use? ›
To specify which private key should be used for connections to a particular remote host, use a text editor to create a ~/.ssh/config that includes the Host and IdentityFile keywords. Once you save the file, SSH will use the specified private key for future connections to that host.
How do I find my security key or passphrase? ›
Most routers come with the network key written on the back or bottom of the router. It's usually labeled with a different name, such as passcode, password, wireless password, or simply security key.
How do I find my ssh credentials? ›
How to view your SSH public key on Windows
- Run the command: ssh-keygen.
- You'll be asked where to save the key.
- If you use the defaults, it will save your keys in C:\User[YourUserName]. sshid.
- You will then be prompted to enter a passphrase. ...
- It will then ask you to confirm the passphrase.
- Your key will be generated.
How to track SSH logins? Use the journalctl -u ssh command on modern Linux systems or check /var/log/auth. log on older systems. The lastlog command can also be used to track the last login of users.
How to get a passphrase? ›
Create a passphrase
- On your Android device, open Chrome .
- On the right of the address bar, tap More Settings. Sync.
- Turn on sync with your Google Account.
- At the bottom, tap Encryption.
- Choose Use your own passphrase to encrypt all the Chrome data in your Google Account.
- Enter and confirm a passphrase.
- Tap Save.
