commit b24f15a9a16acc8009c25823a127f3090b9b2edc Author: Nick Mathewson nickm@torproject.org Date: Tue Mar 15 10:34:05 2016 -0400

In routers_make_ed_keys_unique, break ties for published_on

This ensures that if we can't use published_on to decide an ed,rsa mapping, we at least decide deterministically.

Resolves 17668.T3 --- src/or/dirserv.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/or/dirserv.c b/src/or/dirserv.c index ab8ddfe..ae67e8e 100644 --- a/src/or/dirserv.c +++ b/src/or/dirserv.c @@ -2124,7 +2124,8 @@ get_possible_sybil_list(const smartlist_t *routers) }

/** If there are entries in <b>routers</b> with exactly the same ed25519 keys, - * remove the older one. May alter the order of the list. */ + * remove the older one. If they are exactly the same age, remove the one + * with the greater descriptor digest. May alter the order of the list. */ static void routers_make_ed_keys_unique(smartlist_t *routers) { @@ -2139,7 +2140,12 @@ routers_make_ed_keys_unique(smartlist_t *routers) if ((ri2 = digest256map_get(by_ed_key, pk))) { /* Duplicate; must omit one. Set the omit_from_vote flag in whichever * one has the earlier published_on. */ - if (ri2->cache_info.published_on < ri->cache_info.published_on) { + const time_t ri_pub = ri->cache_info.published_on; + const time_t ri2_pub = ri2->cache_info.published_on; + if (ri2_pub < ri_pub || + (ri2_pub == ri_pub && + memcmp(ri->cache_info.signed_descriptor_digest, + ri2->cache_info.signed_descriptor_digest,DIGEST_LEN)<0)) { digest256map_set(by_ed_key, pk, ri); ri2->omit_from_vote = 1; } else {