Fix up some names, and protobuf tags

Make names (of session_key and message_index) more consistent.

Use our own protobuf tags rather than trying to piggyback on the one-to-one
structure.

3 files changed, 14 insertions, 10 deletions

diff --git a/include/olm/error.h b/include/olm/error.h
index 3f74992..98d2cf5 100644
--- a/include/olm/error.h
+++ b/include/olm/error.h
@@ -32,8 +32,12 @@ enum OlmErrorCode {
     OLM_UNKNOWN_PICKLE_VERSION = 9, /*!< The pickled object is too new */
     OLM_CORRUPTED_PICKLE = 10, /*!< The pickled object couldn't be decoded */
 
-    OLM_BAD_RATCHET_KEY = 11,
-    OLM_BAD_CHAIN_INDEX = 12,
+    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. */
diff --git a/include/olm/inbound_group_session.h b/include/olm/inbound_group_session.h
index 4cf4ac4..e24f377 100644
--- a/include/olm/inbound_group_session.h
+++ b/include/olm/inbound_group_session.h
@@ -91,7 +91,7 @@ size_t olm_unpickle_inbound_group_session(
  * error code. The last_error will be:
  *
  *  * OLM_INVALID_BASE64  if the session_key is not valid base64
- *  * OLM_BAD_RATCHET_KEY if the session_key is invalid
+ *  * OLM_BAD_SESSION_KEY if the session_key is invalid
  */
 size_t olm_init_inbound_group_session(
     OlmInboundGroupSession *session,
@@ -129,9 +129,9 @@ size_t olm_group_decrypt_max_plaintext_length(
  *   * OLM_BAD_MESSAGE_VERSION if the message was encrypted with an unsupported
  *     version of the protocol
  *   * OLM_BAD_MESSAGE_FORMAT if the message headers could not be decoded
- *   * OLM_BAD_MESSAGE_MAC if the message could not be verified
- *   * OLM_BAD_CHAIN_INDEX if we do not have a ratchet key corresponding to the
- *     message's index (ie, it was sent before the ratchet key was shared with
+ *   * OLM_BAD_MESSAGE_MAC    if the message could not be verified
+ *   * OLM_UNKNOWN_MESSAGE_INDEX  if we do not have a session key corresponding to the
+ *     message's index (ie, it was sent before the session key was shared with
  *     us)
  */
 size_t olm_group_decrypt(
diff --git a/include/olm/message.h b/include/olm/message.h
index bd7aec3..cff15f3 100644
--- a/include/olm/message.h
+++ b/include/olm/message.h
@@ -47,7 +47,7 @@ size_t _olm_encode_group_message_length(
  * version:            version number of the olm protocol
  * session_id:         group session identifier
  * session_id_length:  length of session_id
- * chain_index:        message index
+ * message_index:      message index
  * ciphertext_length:  length of the ciphertext
  * output:             where to write the output. Should be at least
  *                     olm_encode_group_message_length() bytes long.
@@ -58,7 +58,7 @@ void _olm_encode_group_message(
     uint8_t version,
     const uint8_t *session_id,
     size_t session_id_length,
-    uint32_t chain_index,
+    uint32_t message_index,
     size_t ciphertext_length,
     uint8_t *output,
     uint8_t **ciphertext_ptr
@@ -69,8 +69,8 @@ struct _OlmDecodeGroupMessageResults {
     uint8_t version;
     const uint8_t *session_id;
     size_t session_id_length;
-    uint32_t chain_index;
-    int has_chain_index;
+    uint32_t message_index;
+    int has_message_index;
     const uint8_t *ciphertext;
     size_t ciphertext_length;
 };