Bug #82931 X protocol: Please provide a formal definition of the MYSQL41 authentication

Description:
The X protocol by default uses the MYSQL41 authentication exchange in a similar way which has been done in the legacy protocol.

Yet strangely enough I see no documentation which describes this protocol.

When writing a new driver for something like the X protocol it saves a considerable amount of time if there's a formal specification with appropriate simple test cases.

How to repeat:
I'm unaware of any formal specification for MYSQL41 authentication. Obviously there are various implementations and not only by Oracle, Sun, MySQL etc and I guess this has therefore required people to study the source code to figure out how this works.

Note: this authentication mechanism also includes information on the default database to connect to, which is something which is not apparent or even mentioned for example here:

https://dev.mysql.com/doc/internals/en/x-protocol-authentication-authentication.html

Suggested fix:
Document the MYSQL41 exchange more formally providing a few sample/test input cases with real values which can be used for validating implementations.

Ensure that this includes the selection of a sample database.

Sample test values which can be used for validation are most useful.

Hello Simon,

Thank you for the report.

Thanks,
Umesh