timoreo/olm
1
1
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

Avoid relying on uint -> int casting behaviour

Browse source 
The behaviour when casting from a uint32_t which has overflowed (so has the top
bit set) to int32_t is implementation-defined, so let's avoid relying on it.
This commit is contained in:
Richard van der Hoff 2016-05-20 12:40:59 +01:00
parent 846ab858a6
commit 173cbe112c
1 changed files with 2 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

4
src/inbound_group_session.c
View file

@ -241,9 +241,9 @@ size_t olm_group_decrypt(
/* pick a megolm instance to use. If we're at or beyond the latest ratchet /* pick a megolm instance to use. If we're at or beyond the latest ratchet
* value, use that */ * value, use that */
if ((int32_t)(decoded_results.message_index - session->latest_ratchet.counter) >= 0) { if ((decoded_results.message_index - session->latest_ratchet.counter) < (1U << 31)) {
megolm = &session->latest_ratchet; megolm = &session->latest_ratchet;
} else if ((int32_t)(decoded_results.message_index - session->initial_ratchet.counter) < 0) { } else if ((decoded_results.message_index - session->initial_ratchet.counter) >= (1U << 31)) {
/* the counter is before our intial ratchet - we can't decode this. */ /* the counter is before our intial ratchet - we can't decode this. */
session->last_error = OLM_UNKNOWN_MESSAGE_INDEX; session->last_error = OLM_UNKNOWN_MESSAGE_INDEX;
return (size_t)-1; return (size_t)-1;