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Request #75645 The server requested authentication method unknown to the client [dialog]
Submitted: 2017-12-07 09:45 UTC Modified: 2021-04-06 21:42 UTC
Avg. Score:4.3 ± 0.8
Reproduced:23 of 23 (100.0%)
Same Version:13 (56.5%)
Same OS:15 (65.2%)
From: michal at cihar dot com Assigned:
Status: Open Package: MySQLi related
PHP Version: 7.2.0 OS: any
Private report: No CVE-ID: None
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 [2017-12-07 09:45 UTC] michal at cihar dot com
PHP fails to authenticate against MariaDB using PAM authentication. 

You can find all details in, which has been reported against mysql extension and closed only because that extension has been deprecated meanwhile, however exactly same problem exists in MySQLi as well.

I've checked current git and the dialog plugin is still not there, so this applies to all PHP versions so far.


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 [2018-02-06 12:48 UTC] kstan at simitgroup dot com
Yes, wish mysqli support PAM authentication. I'm wish to use
 [2018-10-27 01:57 UTC] buphmin at gmail dot com
I have also been able to reproduce this using mysqlnd with PDO and mysqli on php versions 7.0, 7.1, 7.2. I have not yet got around to recompiling PHP to use libmysqlclient to see if that also fails.
 [2019-02-10 17:03 UTC] kstan at simitgroup dot com
I'm manage to recompile the using mariadb client in ubuntu. the gist as this link
 [2019-04-02 20:56 UTC] buphmin at gmail dot com
Thank kstan! I got your gist working in a docker container after a few modifications. I would still prefer mysqlnd supporting PAM auth though.
 [2021-04-06 21:42 UTC]
Hmm, there is a PAM authentification plugin in mysqlnd[1] for
years – I wonder if it's just broken.

[1] <>
 [2022-05-27 21:14 UTC] geoff dot montee at gmail dot com
According to the code linked by, PHP's mysqlnd supports the mysql_clear_password client authentication plugin for PAM (which can be used by both MySQL Server and MariaDB Server), but it probably does not currently support the dialog client authentication plugin for PAM (which can only be used by MariaDB Server).

Users should be able to work around this issue by configuring the pam_use_cleartext_plugin system variable on MariaDB Server to force it to use mysql_clear_password instead of dialog.

I would like to link to a documentation page that describes the problem and solution in more detail, but PHP's bug tracker appears to prohibit links.
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