ssh w/o password

Setting up password-less authentication with OpenSSH

With the default key file

• The first step is to generate a private and a public key on the guest computer. I will issue the following command to generate an RSA key. I could use -t dsa to generate a DSA private key.

• ssh-keygen -t rsa
  

• Now, I have two files in the ~/.sshdirectory of my guest computer: id_rsa and id_rsa.pub
• I will now copy it to my host server with the OpenSSH scp command:

• $ scp ~/.ssh/id_rsa.pub username@hostname:/home/username/.ssh/myguest_id_rsa.pub
  

• On the host, I will now add the contents of the key to the list of authorized keys:

• $ cat myguest_id_rsa.pub >> ~/.ssh/authorized_keys
  

• $ rm myguest_id_rsa.pub
• For better security, let’s set the proper rights on the authorized_keys file. 600 means that the owner only can read and write.

• $ chmod 600 authorized_keys
  

http://stackoverflow.com/questions/3466626/add-private-key-permanently-with-ssh-add-on-ubuntu/4246809#4246809

Error: Agent admitted failure to sign

This error appears to only occur on Linux systems. For more details, see this issue report.

ssh -vT git@github.com
# ...
# Agent admitted failure to sign using the key.
# debug1: No more authentication methods to try.
# Permission denied (publickey).

Resolution

For most users, simply running ssh-add to load your keys into the SSH agent will fix this issue.

ssh-agent bash 

ssh-add 

# Enter passphrase for /home/you/.ssh/id_rsa: [tippy tap]
# Identity added: /home/you/.ssh/id_rsa (/home/you/.ssh/id_rsa)

If your key does not have the default filename, you'll have to pass the path to ssh-add

ssh-add ~/.ssh/my_other_key
# Enter passphrase for /home/you/.ssh/my_other_key: [tappity tap tap]
# Identity added: /home/you/.ssh/my_other_key (/home/you/.ssh/my_other_key) 

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