How do I verify check test validate my SSH passphrase

Question

I think I forgot the passphrase for my SSH key  but I have a hunch what it might be   How do I check if I m right

User · Answer

If your passphrase is to unlock your SSH key and you don't have ssh-agent, but do have sshd (the SSH daemon) installed on your machine, do:

cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys;
ssh localhost -i ~/.ssh/id_rsa

Where ~/.ssh/id_rsa.pub is the public key, and ~/.ssh/id_rsa is the private key.

User · Answer

ssh-keygen -y  ssh-keygen -y will prompt you for the passphrase  if there is one         If you input the correct passphrase  it will show you the associated public key        If you input the wrong passphrase  it will display load failed        If the key has no passphrase  it will not prompt you for a passphrase and will immediately show you the associated public key  e g   Create a new public private key pair  with or without a passphrase    ssh-keygen -f  tmp my key      Now see if you can access the key pair    ssh-keygen -y -f  tmp my key   Following is an extended example  showing output  Create a new public private key pair  with or without a passphrase    ssh-keygen -f  tmp my key Generating public private rsa key pair  Enter passphrase  empty for no passphrase   Enter same passphrase again  Your identification has been saved in  tmp my key  Your public key has been saved in  tmp my key pub  The key fingerprint is  de 24 1b 64 06 43 ca 76 ba 81 e5 f2 59 3b 81 fe rob Robs-MacBook-Pro local The key s randomart image is   --  RSA 2048 ----                              o                                                      o   o S                                     o o                                     E             -----------------   Attempt to access the key pair by inputting the correct passphrase  Note that the public key will be shown and the exit status      will be 0 to indicate success    ssh-keygen -y -f  tmp my key Enter passphrase  ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDBJhVYDYxXOvcQw0iJTPY64anbwSyzI58hht6xCGJ2gzGUJDIsr1NDQsclka6s0J9TNhUEBBzKvh9nTAYibXwwhIqBwJ6UwWIfA3HY13WS161CUpuKv2A PrfK0wLFBDBlwP6WjwJNfi4NwxA21GUS Vcm SuMwaFid9bM2Ap4wZIahx2fxyJhmHugGUFF9qYI4yRJchaVj7TxEmquCXgVf4RVWnOSs9 MTH8YvH wHP4WmUzsDI uaF1SpCyQ1DpazzPWAQPgZv9R8ihOrItLXC1W6TPJkt1CLr YFpz6vapdola8cRw6g jTYms00Yxf2hn0 o8ORpQ9qBpcAjJN   echo    0  Attempt to access the key pair by inputting an incorrect passphrase  Note that the  quot load failed quot  error message will be displayed  message may differ depending on OS  and the exit status      will be 1 to indicate an error    ssh-keygen -y -f  tmp my key Enter passphrase  load failed   echo    1  Attempt to access a key pair that has no passphrase   Note that there is no prompt for the passphrase  the public key will be displayed  and the exit status      will be 0 to indicate success    ssh-keygen -y -f  tmp my key with no passphrase ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDLinxx9T4HE6Brw2CvFacvFrYcOSoQUmwL4Cld4enpg8vEiN8DB2ygrhFtKVo0qMAiGWyqz9gXweXhdmAIsVXqhOJIQvD8FqddA SMgqM  2M7GxgH68N 0V ih7EUqf8Hb2PIeubhkQJQGzB3FjYkvRLZqE oC1Q5nL4B1L1zDQYPSnQKneaRNG NGIaoVwsy6gcCZeqKHywsXBOHLF4F5nf JKqfS6ojStvzajf0eyQcUMDVhdxTN hIfEN HdYbOxHtwDoerv 9f6h2OUxZny1vRNivZxTa 9Qzcet4tkZWibgLmqRyFeTcWh nOJn7K3puFB2kKoJ10q31Tq19   echo    0  Note that the order of arguments is important  -y must come before -f input keyfile  else you will get the error Too many arguments

User · Answer

Use  ssh-keygen -p   You can add  -f    It will prompt you for the old password  If the password is correct  it will prompt to enter a new password  If the old password is incorrect  you will get  Failed to load key  lt

User · Answer

You can verify your SSH key passphrase by attempting to load it into your SSH agent  With OpenSSH this is done via ssh-add   Once you re done  remember to unload your SSH passphrase from the terminal by running ssh-add -d

User · Answer

Extending  RobBednark s solution to a specific Windows   PuTTY scenario  you can do so    Generate SSH key pair with PuTTYgen  following Manually generating your SSH key in Windows   saving it to a PPK file  With the context menu in Windows Explorer  choose Edit with PuTTYgen  It will prompt for a password    If you type the wrong password  it will just prompt again   Note  if you like to type  use the following command on a folder that contains the PPK file  puttygen private-key ppk -y

[ssh] How do I verify/check/test/validate my SSH passphrase?

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