Member kaa_platform_message_reader_create (kaa_platform_message_reader_t **reader_p, const uint8_t *buffer, size_t len): Use KAA_MESSAGE_READER instead – it doesn't allocate memory.
Member kaa_platform_message_writer_create (kaa_platform_message_writer_t **writer_p, uint8_t *buf, size_t len): Use KAA_MESSAGE_WRITER instead – it doesn't allocate memory.
Member kaa_platform_protocol_alloc_serialize_client_sync (kaa_platform_protocol_t *self, const kaa_extension_id *services, size_t services_count, uint8_t **buffer, size_t *buffer_size): You should maintain buffer yourself and call kaa_platform_protocol_serialize_client_sync() directly. The function is defined as a transition to the new approach.