Return the message index when decrypting group messages.

Applications can use the index to detect replays of the same message.

1 files changed, 2 insertions, 1 deletions

diff --git a/include/olm/inbound_group_session.h b/include/olm/inbound_group_session.h
index 59146c2..f8a0bc3 100644
--- a/include/olm/inbound_group_session.h
+++ b/include/olm/inbound_group_session.h
@@ -140,7 +140,8 @@ size_t olm_group_decrypt(
     uint8_t * message, size_t message_length,
 
     /* output */
-    uint8_t * plaintext, size_t max_plaintext_length
+    uint8_t * plaintext, size_t max_plaintext_length,
+    uint32_t * message_index
 );