Re: tramp and ssh-key passphrase

["Peter Münster" <pmlists@free.fr>]

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On Mon, Feb 29 2016, Michael Albinus wrote:

> There is the recommendation to use ssh-agent, which is always good.

Indeed.

And if
- you want to type the passphrase only once at the start of your
  X-session
- and your ssh-passphrase is the same as your gpg-passphrase
- and the passphrase should never expire
- and ssh-connections should work from cron-jobs,

then you could
- copy the attached askpass.lisp file to ~/bin
- and fill the list of the fingerprints
- and copy the attached gpg-agent.conf to ~/.gnupg
- and put these 2 lines to your ~/.xinitrc:
  SSH_ASKPASS=~/bin/askpass.lisp ssh-add
  echo $SSH_AUTH_SOCK >~/.ssh/ssh-auth-sock
- and start your cron-job shell scripts with
  export SSH_AUTH_SOCK=`cat ~/.ssh/ssh-auth-sock`

-- 
           Peter

[-- Attachment #2: askpass.lisp --]
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#!/usr/bin/sbcl --script

;; vielleicht so:
;; gpg --list-secret-keys --with-fingerprint --with-fingerprint --with-colon
;; --list-options no-show-unusable-uids,no-show-unusable-subkeys | sed -rn 's/^fpr:::::::::(.*):/\1/p'

(defvar *fingerprints*
  (list "XXX"
        "YYY"
        "ZZZ"))

(with-output-to-string (out)
  (run-program "/usr/lib/ssh/ssh-askpass" nil :output out)
  (let ((s (get-output-stream-string out)))
    (dolist (fp *fingerprints*)
      (with-input-from-string (in s)
        (run-program "/usr/lib64/gpg-preset-passphrase" (list "--preset" fp)
                     :input in :output nil)))
    (princ s)))

[-- Attachment #3: gpg-agent.conf --]
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allow-preset-passphrase
default-cache-ttl 99999999
max-cache-ttl 99999999