Variable: server-auth-key

server-auth-key is a customizable variable defined in server.el.gz.

Value

nil

Documentation

Server authentication key.

This is only used if server-use-tcp is non-nil.

Normally, the authentication key is randomly generated when the server starts. It is recommended to leave it that way. Using a long-lived shared key will decrease security (especially since the key is transmitted as plain-text).

In some situations however, it can be difficult to share randomly generated passwords with remote hosts (e.g., no shared directory), so you can set the key with this variable and then copy the server file to the remote host (with possible changes to IP address and/or port if that applies).

Note that the usual security risks of using the server over remote TCP, arising from the fact that client-server communications are unencrypted, still apply.

The key must consist of 64 ASCII printable characters except for space (this means characters from ! to ~; or from code 33 to
126). You can use M-x server-generate-key (server-generate-key) to get a random key.

This variable was added, or its default value changed, in Emacs 24.3.

View in manual

Probably introduced at or before Emacs version 24.3.

Source Code

;; Defined in /usr/src/emacs/lisp/server.el.gz
(defcustom server-auth-key nil
  "Server authentication key.
This is only used if `server-use-tcp' is non-nil.

Normally, the authentication key is randomly generated when the
server starts.  It is recommended to leave it that way.  Using a
long-lived shared key will decrease security (especially since
the key is transmitted as plain-text).

In some situations however, it can be difficult to share randomly
generated passwords with remote hosts (e.g., no shared directory),
so you can set the key with this variable and then copy the
server file to the remote host (with possible changes to IP
address and/or port if that applies).

Note that the usual security risks of using the server over
remote TCP, arising from the fact that client-server
communications are unencrypted, still apply.

The key must consist of 64 ASCII printable characters except for
space (this means characters from ! to ~; or from code 33 to
126).  You can use \\[server-generate-key] to get a random key."
  :type '(choice
	  (const :tag "Random" nil)
	  (string :tag "Password"))
  :version "24.3")