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author | Matthias Schiffer <mschiffer@universe-factory.net> | 2013-11-29 06:01:32 +0100 |
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committer | Matthias Schiffer <mschiffer@universe-factory.net> | 2013-11-29 06:03:33 +0100 |
commit | f04696e7451f787112e35ac184ff5057f45269eb (patch) | |
tree | 5a3e5bb2550fb1dad4bba471954f80c5c5315b14 /src/methods | |
parent | 30016f8c828ae2d8191d5490cf599bbf006d024b (diff) | |
download | fastd-f04696e7451f787112e35ac184ff5057f45269eb.tar fastd-f04696e7451f787112e35ac184ff5057f45269eb.zip |
Reorder check: avoid undefined behaviour due to negative or to long shifts
Diffstat (limited to 'src/methods')
-rw-r--r-- | src/methods/common.c | 13 |
1 files changed, 10 insertions, 3 deletions
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; |