SSH Without a Password

Steps:

1. On the client run the following commands:
   

   $ mkdir -p $HOME/.ssh
   $ chmod 0700 $HOME/.ssh
   $ ssh-keygen -t dsa -f $HOME/.ssh/id_dsa -P ''
   

   This should result in two files, $HOME/.ssh/id_dsa (private key) and $HOME/.ssh/id_dsa.pub (public key).
2. Copy $HOME/.ssh/id_dsa.pub to the server.
3. On the server run the following commands:
   

   $ cat id_dsa.pub >> $HOME/.ssh/authorized_keys2
   $ chmod 0600 $HOME/.ssh/authorized_keys2
   

   Depending on the version of OpenSSH the following commands may also be required:

   $ cat id_dsa.pub >> $HOME/.ssh/authorized_keys
   $ chmod 0600 $HOME/.ssh/authorized_keys
   

   An alternative is to create a link from authorized_keys2 to authorized_keys:

   $ cd $HOME/.ssh && ln -s authorized_keys2 authorized_keys
   

4. On the client test the results by ssh'ing to the server:
   

   $ ssh -i $HOME/.ssh/id_dsa server
   

5. (Optional) Add the following $HOME/.ssh/config on the client:
   

   Host server
            IdentityFile ~/.ssh/id_dsa
   

   This allows ssh access to the server without having to specify the path to the id_dsa file as an argument to ssh each time.

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注意检查.ssh目录和authorized_keys文件的权限。