Standard Training: SSH - Secure Shell Login¶

• login to remote host using current username (i.e., $USER envirnment variable in Unix-like systems):

  ssh host
  

• login to remote host using specific username (e.g., foo):

  ssh foo@host
  

• generate a ssh key pair using RSA cryptosystem

  ssh-keygen  # continue pressing the enter key to use default settings
  ls ~/.ssh   # check the new key pairs
  

• install public key to remote server host (please replace host with where you are copying your public key):

  ssh-copy-id host     # run this on your local computer (not on the remote host)
  

cat ~/.ssh/id_rsa.pub # get unmodified content of the public key (for copying)
# on another machine paste public key in ~/.ssh/authorized_keys for keyless login

• scp works similar to cp and copies file foo from user1@host1 to user2@host2 as bar:

  scp user1@host1:/path/to/foo user2@host2:/path/to/bar
  

• When host and user are not specified they are treated as your localhost and $USER; if a path is not given, the path is assumed to be in the $HOME folder. As an example, to copy a file output from $HOME on cruntch4 back to current directory of the local machine can be done via:

  scp <euid>@cruntch4.chem.unt.edu:output .
  

• To copy, multiple files in one-shot, one can first make a tarball via tar and do scp:

  tar -cf folder.tar folder/
  mv folder.tar ~
  scp <euid>@cruntch4.chem.unt.edu:folder.tar .
  

• Other remote copying options are: sftp or sshfs. One may also use a GUI to help; see this thread for some options

To login to hosts with longer name or with a different user id, one can add custom configurations in ~/.ssh/config

• simplify ssh login to from ssh EUID@cruntch4.chem.unt.edu to ssh cruntch4, one can add the following lines in ~/.ssh/config (replace EUID with your EUID):

  Host     cruntch4
  User     EUID
  HostName cruntch4.chem.unt.edu
  

• build the tunnel with the host and connect to a local port (5000 in this case)

  ssh -D 5000 -N host     # 5000 is an arbitrary port
  

• set up browser proxy to redirect traffic, e.g., when using Firefox change Connection settings to: