From f04696e7451f787112e35ac184ff5057f45269eb Mon Sep 17 00:00:00 2001 From: Matthias Schiffer Date: Fri, 29 Nov 2013 06:01:32 +0100 Subject: Reorder check: avoid undefined behaviour due to negative or to long shifts --- src/methods/common.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) (limited to 'src/methods') diff --git a/src/methods/common.c b/src/methods/common.c index 7c67253..9308332 100644 --- a/src/methods/common.c +++ b/src/methods/common.c @@ -63,7 +63,7 @@ bool fastd_method_is_nonce_valid(fastd_context_t *ctx, const fastd_method_common if (timespec_diff(&ctx->now, &session->receive_last) > (int)ctx->conf->reorder_time*1000) return false; - if (*age > ctx->conf->reorder_count) + if (*age > 64) return false; } @@ -72,8 +72,15 @@ bool fastd_method_is_nonce_valid(fastd_context_t *ctx, const fastd_method_common bool fastd_method_reorder_check(fastd_context_t *ctx, fastd_peer_t *peer, fastd_method_common_t *session, const uint8_t nonce[COMMON_NONCEBYTES], int64_t age) { if (age < 0) { - session->receive_reorder_seen >>= age; - session->receive_reorder_seen |= (1 >> (age+1)); + size_t shift = age < (-64) ? 64 : ((size_t)-age); + + if (shift > 63) + session->receive_reorder_seen = 0; + else + session->receive_reorder_seen <<= shift; + + session->receive_reorder_seen |= (1 << (shift-1)); + memcpy(session->receive_nonce, nonce, COMMON_NONCEBYTES); session->receive_last = ctx->now; return true; -- cgit v1.2.3