making clearer comments in the transition script, invoking from postinst for debian.

[monkeysphere.git] / src / share / common

diff --git a/src/share/common b/src/share/common
index 9adae05e894a5a8aedeca0d5bdd41f122b897a44..a2f449464fe60e2ce629fed36866304407ef7106 100644 (file)
--- a/src/share/common
+++ b/src/share/common
@@ -8,7 +8,7 @@
 # Jamie McClelland <jm@mayfirst.org>
 # Daniel Kahn Gillmor <dkg@fifthhorseman.net>
 #
-# Copyright 2008, released under the GPL, version 3 or later
+# Copyright 2008-2009, released under the GPL, version 3 or later
 
 # all-caps variables are meant to be user supplied (ie. from config
 # file) and are considered global
@@ -21,7 +21,7 @@ SYSCONFIGDIR=${MONKEYSPHERE_SYSCONFIGDIR:-"/etc/monkeysphere"}
 export SYSCONFIGDIR
 
 # monkeysphere version
-VERSION=__VERSION__
+VERSION=0.23~pre
 
 ########################################################################
 ### UTILITY FUNCTIONS
@@ -34,7 +34,8 @@ failure() {
 
 # write output to stderr based on specified LOG_LEVEL the first
 # parameter is the priority of the output, and everything else is what
-# is echoed to stderr
+# is echoed to stderr.  If there is nothing else, then output comes
+# from stdin, and is not prefaced by log prefix.
 log() {
     local priority
     local level
@@ -79,12 +80,50 @@ log() {
            output=true
        fi
        if [ "$priority" = "$level" -a "$output" = 'true' ] ; then
-           echo -n "ms: " >&2
-           echo "$@" >&2
+           if [ "$1" ] ; then
+               echo -n "ms: " >&2
+               echo "$@" >&2
+           else
+               cat >&2
+           fi
        fi
     done
 }
 
+# run command as monkeysphere user
+su_monkeysphere_user() {
+    # our main goal here is to run the given command as the the
+    # monkeysphere user, but without prompting for any sort of
+    # authentication.  If this is not possible, we should just fail.
+
+    # FIXME: our current implementation is overly restrictive, because
+    # there may be some su PAM configurations that would allow su
+    # "$MONKEYSPHERE_USER" -c "$@" to Just Work without prompting,
+    # allowing specific users to invoke commands which make use of
+    # this user.
+
+    # chpst (from runit) would be nice to use, but we don't want to
+    # introduce an extra dependency just for this.  This may be a
+    # candidate for re-factoring if we switch implementation languages.
+
+    case $(id -un) in
+       # if monkeysphere user, run the command under bash
+       "$MONKEYSPHERE_USER")
+           bash -c "$@"
+           ;;
+
+         # if root, su command as monkeysphere user
+       'root')
+           su "$MONKEYSPHERE_USER" -c "$@"
+           ;;
+
+       # otherwise, fail
+       *)
+           log error "non-privileged user."
+           ;;
+    esac
+}
+
 # cut out all comments(#) and blank lines from standard input
 meat() {
     grep -v -e "^[[:space:]]*#" -e '^$' "$1"
@@ -95,6 +134,11 @@ cutline() {
     head --line="$1" "$2" | tail -1
 }
 
+# make a temporary directly
+msmktempdir() {
+    mktemp -d ${TMPDIR:-/tmp}/tmp.XXXXXXXXXX
+}
+
 # this is a wrapper for doing lock functions.
 #
 # it lets us depend on either lockfile-progs (preferred) or procmail's
@@ -118,6 +162,7 @@ lock() {
            else
                lockfile -r 20 "${file}.lock" || failure "unable to lock '$file'"
            fi
+           log debug "lock created on '$file'."
            ;;
        touch)  
            if [ -n "$use_lockfileprogs" ] ; then
@@ -125,6 +170,7 @@ lock() {
            else
                : Nothing to do here
            fi
+           log debug "lock touched on '$file'."
            ;;
        remove)
            if [ -n "$use_lockfileprogs" ] ; then
@@ -132,6 +178,7 @@ lock() {
            else
                rm -f "${file}.lock"
            fi
+           log debug "lock removed on '$file'."
            ;;
        *)
            failure "bad argument for lock subfunction '$action'"
@@ -412,6 +459,8 @@ check_key_file_permissions() {
     uname="$1"
     path="$2"
 
+    log debug "checking path permission '$path'..."
+
     # return 255 if cannot stat file
     if ! stat=$(ls -ld "$path" 2>/dev/null) ; then
         log error "could not stat path '$path'."
@@ -1000,6 +1049,8 @@ update_authorized_keys() {
 
     # remove the lockfile and the trap
     lock remove "$AUTHORIZED_KEYS"
+
+    # remove the trap
     trap - EXIT
 
     # note if the authorized_keys file was updated
@@ -1049,3 +1100,14 @@ process_authorized_user_ids() {
 
     update_authorized_keys "${userIDs[@]}"
 }
+
+# takes a gpg key or keys on stdin, and outputs a list of
+# fingerprints, one per line:
+list_primary_fingerprints() {
+    local file="$1"
+    local fake=$(msmktempdir)
+    GNUPGHOME="$fake" gpg --no-tty --quiet --import
+    GNUPGHOME="$fake" gpg --with-colons --fingerprint --list-keys | \
+       awk -F: '/^fpr:/{ print $10 }'
+    rm -rf "$fake"
+}