SSH Login PROCESS

출처 : # man sshd

When a user successfully logs in, sshd does the following:

 1.   If the login is on a tty, and no command has been specified, prints last login time and /etc/motd (unless prevented in the configuration file or by ~/.hushlogin; see the FILES section).

 2.   If the login is on a tty, records login time.

 3.   Checks /etc/nologin; if it exists, prints contents and quits (unless root).

 4.   Changes to run with normal user privileges.

 5.   Sets up basic environment.

 6.   Reads the file ~/.ssh/environment, if it exists, and users are allowed to change their environment.  See the PermitUserEnvironment option in sshd_config(5).

 7.   Changes to user’s home directory.

 8.   If ~/.ssh/rc exists, runs it; else if /etc/ssh/sshrc exists, runs it; otherwise runs xauth.  The “rc” files are given the X11 authentication protocol and cookie in standard input.  See SSHRC, below.

 9.   Runs user’s shell or command.