Sign megolm messages

Add ed25519 keys to the inbound and outbound sessions, and use them to sign and
verify megolm messages.

We just stuff the ed25519 public key in alongside the megolm session key (and
add a version byte), to save adding more boilerplate to the JS/python/etc
layers.

1 files changed, 5 insertions, 0 deletions

diff --git a/include/olm/error.h b/include/olm/error.h
index 1c44de8..9d44a94 100644
--- a/include/olm/error.h
+++ b/include/olm/error.h
@@ -46,6 +46,11 @@ enum OlmErrorCode {
      */
     OLM_BAD_LEGACY_ACCOUNT_PICKLE = 13,
 
+    /**
+     * Received message had a bad signature
+     */
+    OLM_BAD_SIGNATURE = 14,
+
     /* remember to update the list of string constants in error.c when updating
      * this list. */
 };