svn commit: r306418 - stable/11/usr.sbin/portsnap/portsnap

[Ed Maste]

Author: emaste
Date: Wed Sep 28 21:33:35 2016
New Revision: 306418
URL: https://svnweb.freebsd.org/changeset/base/306418

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.
  
  Approved by:	re (gjb)

Modified:
  stable/11/usr.sbin/portsnap/portsnap/portsnap.sh
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/usr.sbin/portsnap/portsnap/portsnap.sh
==============================================================================
--- stable/11/usr.sbin/portsnap/portsnap/portsnap.sh	Wed Sep 28 21:22:51 2016	(r306417)
+++ stable/11/usr.sbin/portsnap/portsnap/portsnap.sh	Wed Sep 28 21:33:35 2016	(r306418)
@@ -691,6 +691,13 @@ 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