1 files changed, 13 insertions, 0 deletions
diff --git a/include/olm/error.h b/include/olm/error.h
index a4f373e..98d2cf5 100644
--- a/include/olm/error.h
+++ b/include/olm/error.h
@@ -31,8 +31,21 @@ enum OlmErrorCode {
     OLM_BAD_ACCOUNT_KEY = 8, /*!< The supplied account key is invalid */
     OLM_UNKNOWN_PICKLE_VERSION = 9, /*!< The pickled object is too new */
     OLM_CORRUPTED_PICKLE = 10, /*!< The pickled object couldn't be decoded */
+
+    OLM_BAD_SESSION_KEY = 11,  /*!< Attempt to initialise an inbound group
+                                 session from an invalid session key */
+    OLM_UNKNOWN_MESSAGE_INDEX = 12,  /*!< Attempt to decode a message whose
+                                      * index is earlier than our earliest
+                                      * known session key.
+                                      */
+
+    /* remember to update the list of string constants in error.c when updating
+     * this list. */
 };
 
+/** get a string representation of the given error code. */
+const char * _olm_error_to_string(enum OlmErrorCode error);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif