add keys-for-user subcommand to monkeysphere-authentication

This subcommand will output all valid key for a given user.  The
user's authorized_user_ids file will be read for OpenPGP user IDs, one
per line.  The ssh-formated RSA keys will be output to stdout.

Also included is a simple script that takes the user as it's one
argument and exec's this command.  This is something that would be
suitable for the proposed sshd AuthorizedKeysCommand.

1 files changed, 50 insertions, 0 deletions

diff --git a/src/share/ma/keys_for_user b/src/share/ma/keys_for_user
new file mode 100644
index 0000000..f48d5d3
--- /dev/null
+++ b/src/share/ma/keys_for_user
@@ -0,0 +1,50 @@
+# -*-shell-script-*-
+# This should be sourced by bash (though we welcome changes to make it POSIX sh compliant)
+
+# Monkeysphere authentication keys-for-user subcommand
+#
+# The monkeysphere scripts are written by:
+# Jameson Rollins <jrollins@finestructure.net>
+# Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+#
+# They are Copyright 2008-2010, and are all released under the GPL,
+# version 3 or later.
+
+# This command could be run as an sshd AuthorizedKeysCommand to
+# provide the authorized keys for a user, based on OpenPGP user id's
+# listed in the user's authorized_user_ids file.
+
+keys_for_user() {
+
+local uname
+local authorizedUserIDs
+local line
+local userIDs
+
+# get users from command line
+uname="$1"
+
+# path to authorized_user_ids file, translating ssh-style path
+# variables
+authorizedUserIDs=$(translate_ssh_variables "$uname" "$AUTHORIZED_USER_IDS")
+
+# exit if the authorized_user_ids file is empty
+if [ ! -s "$authorizedUserIDs" ] ; then
+    failure "authorized_user_ids file '$authorizedUserIDs' is empty or does not exist."
+fi
+
+log debug "authorized_user_ids file: $authorizedUserIDs"
+
+# check permissions on the authorized_user_ids file path
+check_key_file_permissions "$uname" "$authorizedUserIDs" || failure
+
+GNUPGHOME="$GNUPGHOME_SPHERE"
+export GNUPGHOME
+
+# extract user IDs from authorized_user_ids file
+IFS=$'\n'
+for line in $(meat "$authorizedUserIDs") ; do
+    su_monkeysphere_user ". ${SYSSHAREDIR}/common; keys_for_userid '$line'"
+done
+
+}