The opt_for_user subrule was incorrectly scanned before sp_create_assignment_lex(),
so the user name and the host were created on a wrong memory root.
- Reoganizing the grammar to make sure that sp_create_assignment_lex()
is called immediately after PASSWORD_SYM is scanned, so all attributes
are then allocated on its memory root.
- Moving the semantic code as methods to LEX, so the grammar looks as simple as possible.
- Changing text_or_password to be of the data type USER_AUTH*.
As a side effect, the LEX::definer member is now not used when processing
the SET PASSWORD statement. Everything is done using Bison's stack.
The bug sas introduced by this commit:
commit bf5a144e16
Support SET PASSWORD for authentication plugins.
Authentication plugin API is extended with two optional methods:
* hash_password() is used to compute a password hash (or digest)
from the plain-text password. This digest will be stored in mysql.user
table
* preprocess_hash() is used to convert this digest into some memory
representation that can be later used to authenticate a user.
Build-in plugins convert the hash from hexadecimal or base64 to binary,
to avoid doing it on every authentication attempt.
Note a change in behavior: when loading privileges (on startup or on
FLUSH PRIVILEGES) an account with an unknown plugin was loaded with a
warning (e.g. "Plugin 'foo' is not loaded"). But such an account could
not be used for authentication until the plugin is installed. Now an
account like that will not be loaded at all (with a warning, still).
Indeed, without plugin's preprocess_hash() method the server cannot know
how to load an account. Thus, if a new authentication plugin is
installed run-time, one might need FLUSH PRIVILEGES to activate all
existing accounts that were using this new plugin.
Don't distinguish between a "password hash" and "authentication string"
anymore. Now both are stored in mysql.user.authentication_string, both
are handled identically internally. A "password hash" is just how some
particular plugins interpret authentication string.
Set mysql.user.plugin even if there is no password. The server will use
mysql_native_password plugin in these cases, let's make it expicit.
Remove LEX_USER::pwhash.
