Add instructions to SSH call

[etc/offlineimap.git] / .offlineimap / preauthtunnel.sh

diff --git a/.offlineimap/preauthtunnel.sh b/.offlineimap/preauthtunnel.sh
index 09769746e0f8e6f8ff85e8f67944a857d59c513a..c99f59b2bfa839aa83dfed05e37b8d9c8ae23d3e 100755 (executable)
--- a/.offlineimap/preauthtunnel.sh
+++ b/.offlineimap/preauthtunnel.sh
@@ -1,3 +1,19 @@
 #!/bin/sh
 
-exec ssh -F ~/.offlineimap/ssh_config -i ~/.offlineimap/${1}.ssh-seckey ${1}
+unset SSH_AUTH_SOCK
+
+exec ssh -F ~/.offlineimap/ssh_config -i ~/.offlineimap/${1}.ssh-seckey ${1} \
+  echo -e "Please configure \~/.ssh/authorized_keys on the server and prepend the line with the public key corresponding to the password-less SSH key in ~/.offlineimap/${1}.ssh-seckey :\\\n\\\n  'command=\"MAIL=\$HOME/.maildir /usr/lib/dovecot/imap 2>/dev/null\",no-agent-forwarding,no-X11-forwarding,no-port-forwarding,no-pty'"
+
+# This relies on the IMAP command being specified on the server side, i.e. in
+# ~/.ssh/authorized_keys, put a line like the following
+#
+#   command="MAIL=$HOME/.maildir /usr/lib/dovecot/imap 2>/dev/null",no-agent-forwarding,no-X11-forwarding,no-port-forwarding,no-pty ssh-ed25519 AAA…
+#
+# When a command is specified like this, it overrides the instructions being
+# passed in the command above. So, when you invoke this script directly, you
+# should see the IMAP server greet you:
+#
+# % ~/.offlineimap/preauthtunnel.sh madduck-net.imap.madduck.net
+# * PREAUTH [CAPABILITY IMAP4rev1 […]] Logged in as madduck
+