svn commit: r306697 - stable/10/usr.sbin/portsnap/portsnap

[Ed Maste]

Author: emaste
Date: Wed Oct  5 00:33:06 2016
New Revision: 306697
URL: https://svnweb.freebsd.org/changeset/base/306697

Log:
  MFC r306417: portsnap: only move expected snapshot contents from snap/ to files/
  
  Previously it was possible to smuggle in addional files that would
  be used by later portsnap runs. Now we only move those files expected
  to be in the snapshot into files/ and require that there are no
  unexpected files.
  
  This was used by portsnap attacks 2, 3, and 4 in the "non-cryptanalytic
  attacks against FreeBSD update components" anonymous gist.

Modified:
  stable/10/usr.sbin/portsnap/portsnap/portsnap.sh
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/usr.sbin/portsnap/portsnap/portsnap.sh
==============================================================================
--- stable/10/usr.sbin/portsnap/portsnap/portsnap.sh	Tue Oct  4 23:12:35 2016	(r306696)
+++ stable/10/usr.sbin/portsnap/portsnap/portsnap.sh	Wed Oct  5 00:33:06 2016	(r306697)
@@ -686,6 +686,13 @@ fetch_snapshot() {
 	fetch_index_sanity || return 1
 # Verify the snapshot contents
 	cut -f 2 -d '|' INDEX.new | fetch_snapshot_verify || return 1
+	cut -f 2 -d '|' tINDEX.new INDEX.new | sort -u > files.expected
+	find snap -mindepth 1 | sed -E 's^snap/(.*)\.gz^\1^' | sort > files.snap
+	if ! cmp -s files.expected files.snap; then
+		echo "unexpected files in snapshot."
+		return 1
+	fi
+	rm files.expected files.snap
 	echo "done."
 
 # Move files into their proper locations