pam_mysql errors: symbol my_make_scrambled_password and dlerror

 

.. old Linux always works, newer ones are shit, but here we are.. lest fix that crap: pam_mysql just dont load in Debian, cos is moved over a "secure locations, also, comes with some problems in Debian 7, Debian 8 and Debian 9 if you used differents Mysql/Mariadb versions. Here the simple and other solutions:

1. dlerror problems

In the system log /var/auth/log we will see PAM unable to dlopen(pam_mysql.so): /lib/security/pam_mysql.so: cannot open shared object file: No such file or directory this is due in debian since wheezy we have multiarch and also the pam mysql module were moved to "secure" location, this is under "{DEB_HOST_MULTIARCH}" (by example, /lib/x86_64-linux-gnu/security/pam_mysql.so under amd64/emt64 or /lib/i386-linux-gnu/security/pam_mysql.so under x86 systems).

By example a xxx pam mysql module will change from 

auth    optional pam_mysql.so config_file=/etc/libpam-mysql.conf

To this

account required /lib/i386-linux-gnu/security/pam_mysql.so config_file=/etc/libpam-mysql.conf

When made packages you should use in the configure step the "--with-pam-mods-dir=" parameter, the path must be dinamically asigned based on your distribution, in debian and alpine you shoul use the multiarch path to set the right location as we cited above.

If in the system log /var/auth/log we will see  PAM [dlerror: /lib/security/pam_mysql.so: undefined symbol: pam_get_item this is due you are using older debian, for wheezy i backported the package that fixeds (since 0.8.X) in VenenuX repos. So for that you must also check the nest section:

2. pam_mysql errors symbols

This second problem is very common today and is happening after the recent mysql 5.7 and such variations like percona server or mariadb ones, many functions were removed from mysql lib and such forks just follow the same behaviour, is not easy to solve problem and the most faster and safe way is to use the 0.7rc version and older mysql/mariadb/percona release.

May after correct setup you will see in /var/auth/log those erros: pam_mysql errors: symbol my_make_scrambled_password this is due some deprecations on the mysql (and related) libraries.. a older patch for 0.7 was given years ago but now 0.8.1 already solved, so i backported as i said previously the package for all debians since wheezy:

https://build.opensuse.org/package/show/home:vegnuli:system-vnx1/pam-mysql

Those packages are a work in progress and if you still wants to use it, just install/enable VenenuX repository and use it, Debian 11 adn so does not suffer from this second problem.