From 609065f165a8e145f404e55e01e8f5ac5c013bc3 Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Mon, 2 Jan 2017 14:55:39 -0500 Subject: DefecTor countermeasure: change server- and client-side DNS TTL clipping The server-side clipping now clamps to one of two values, both for what to report, and how long to cache. Additionally, we move some defines to dns.h, and give them better names. --- changes/ticket19769 | 7 +++++++ 1 file changed, 7 insertions(+) create mode 100644 changes/ticket19769 (limited to 'changes') diff --git a/changes/ticket19769 b/changes/ticket19769 new file mode 100644 index 0000000000..9fc05c3e9e --- /dev/null +++ b/changes/ticket19769 @@ -0,0 +1,7 @@ + o Major features (security): + - Change the algorithm used to decide DNS TTLs on client and server side, + to better resist DNS-based correlation attacks like the DefecTor attack + of Greschbach, Pulls, Roberts, Winter, and Feamster). Now + relays only return one of two possible DNS TTL values, and clients + are willing to believe DNS TTL values up to 3 hours long. + Closes ticket 19769. -- cgit v1.2.3-54-g00ecf