After adding semi-sync to develop we can start checking which part of the code would be affected.

Notification to slaves, instead of live distribution, will also simplify the task.

WAIT_DATA slave state instead of FOLLOW will be added.

Added WAIT_DATA in "binlog_server_wait_data"

After proper tests, binlog encryption estimate work could start

Started adding START_ENCRYPTION_EVENT detection in blr_read_events_all_events()

2016-08-11 18:02:35 debug : - START_ENCRYPTION event @ 249, size 36, next pos is @ 285, flags 0
2016-08-11 18:02:35 debug : Encryption scheme: 1, key_version: 1, nonce: 89968FBC5C3D16B00D7D81EE

START_ENCRYPTION_EVENT event must not be sent to slave.

Next event, after Format Description Event, will the decrypted event.

Being the START_ENCRYPTION_EVENT a 36 byte packet and say the FDE event next pos in the header 249 the first event to be sent will be the one at pos:

249 (next pos in FDE header) + 36 = 285

So FDE next pos is 249 but the event sent is the one at 285

The slave routine that reads data from binlog file should first skip this event.

the IV for event encryption/decryption is 12 bytes from 'nonce' read START_ENCRYPTION_EVENT + current_event_pos (4) bytes = 16 bytes

encrypted events are encrypted with key and IV (12 nonce + event_pos) and they have same size as "plain" events.

That's possible via XOR and later data truncation

The saved encrypted event is event_size-4 long and that size is written, clear data, at event_pos +9

In order to enc/dec first 4 bytes of event have to be moved into event_pos +9 and then encrypt/decrypt sarting from buff+4

Added "start_encryption_event" into blr_write_binlog_record(), just after writing of FDE event

blr_slave_catchup() now skips MARIADB10_START_ENCRYPTION_EVENT, IGNORABLE_EVENT or any event with flag LOG_EVENT_IGNORABLE_F

Slave pos pointer is set to next event pos

blr_read_events_all_events() now detects START_ENCRYPTION and follows event position (events are encrypted but position is in clear)

blr.c:createInstance() detects whether START_ENCRYPTION is in current binlog file but binlog encryption is Off. In this case replication is stopped.