Bug #110623 Connection fails with "Couldn't read RSA public key from server"

Description:
Following update from 8.0.32 from 8.0.31, the database connection is not working anymore from the application (Zabbix) to the MySQL router loopback.
According the application error message:
"[Z3001] connection to database 'zabbix' failed: [2061] Couldn't read RSA public key from server"

Log from MySQL router:
[...]
2023-04-06 10:28:58 metadata_cache DEBUG [7f2cb82be640] End updating cluster for 'ZabbixCluster'
2023-04-06 10:28:58 metadata_cache DEBUG [7f2cb82be640] Finished refreshing the cluster metadata
2023-04-06 10:28:58 routing DEBUG [7f2cba2c2640] [routing:bootstrap_rw] fd=71 connection accepted at 0.0.0.0:6446
2023-04-06 10:28:58 routing DEBUG [7f2cc12d0640] [routing:bootstrap_rw] connected 127.0.0.1:35682 -> [hidden]:3306
2023-04-06 10:28:58 routing DEBUG [7f2cc12d0640] [routing:bootstrap_rw] fd=71 -- 75: connection closed (up: 137b; down: 258b)
2023-04-06 10:28:58 routing DEBUG [7f2cc12d0640] [routing:bootstrap_rw] fd=71 -- (not connected): connection closed (up: 137b; down: 258b)
2023-04-06 10:28:58 metadata_cache DEBUG [7f2cb82be640] Started refreshing the cluster metadata
[...]

Wireshark analyze:
8.0.31 (Zabbix <-> MySQLrouter): no encryption
[...]
--> Login Request
<-- ACK
<-- Auth Switch Request (Auth Method Name: 0103, Auth Method Data: *empty*)
<-- Response OK
--> ACK
--> Request Query
<-- Response OK
--> Request Query
<-- Response OK
--> Request Use Database
<-- Response OK
[...]

8.0.32 (Zabbix <-> MySQLrouter):
[...]
--> Login Request
<-- ACK
<-- Response OK
--> Request Use Database
<-- Response Error 1156
<-- FIN

The direct connection (without MySQL router) works as expected. For information the Zabbix version is 6.4.1

How to repeat:
Upgrade to 8.0.32

Suggested fix:
Downgrade to 8.0.31

Thanks for the report

I mean "Following an update from 8.0.31 to 8.0.32"

Same issue following upgrade. Any update ? It's blocking point ... no upgrade is possible anymore.

Posted by developer:
 
Reopened as Bug#112167