Percona PAM doesn't support spaces for groups

Updates:
The group name supports hyphen(eg. my-group) but for authentication it requires that it be case sensitive which is the same for providing the user too.

Unfortunately, for testing spaces in group, it requires Samba/Active Directory because these infra supports spaces in groups.

To reproduce:

Sample LDAP accounts. Take note that LDAP and Active directory allows groups with spaces:
[root@9292447ef160 ~]# id rjennings
uid=10005(rjennings) gid=10001(dba) groups=10001(dba),10003(database_administrators)
[root@9292447ef160 ~]# id bmccray
uid=10001(bmccray) gid=10000(domain users) groups=10000(domain users),10001(dba)
[root@9292447ef160 ~]# id erosales
uid=10002(erosales) gid=10000(domain users) groups=10000(domain users),10002(developer)
[root@9292447ef160 ~]# id hmcdaniel
uid=10003(hmcdaniel) gid=10000(domain users) groups=10000(domain users),10004(api developers)
[root@9292447ef160 ~]# id lnunez
uid=10004(lnunez) gid=10000(domain users) groups=10000(domain users)

PAM plugin setup:
mysql> delete from mysql.user where user='';
Query OK, 2 rows affected (0.00 sec)
mysql> INSTALL PLUGIN auth_pam SONAME 'auth_pam.so';
Query OK, 0 rows affected (0.00 sec)
mysql> create user ''@'' identified with auth_pam as 'mysqld,dba=mysql_dba,developer=mysql_dev,api developers=mysql_api';
Query OK, 0 rows affected (0.00 sec)
mysql> grant all privileges on *.* to mysql_dba@'%' ;
Query OK, 0 rows affected (0.00 sec)
mysql> grant all privileges on *.* to mysql_dba@'%' with grant option;
Query OK, 0 rows affected (0.00 sec)
mysql> grant insert,select,update,delete on *.* to 'mysql_dev'@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> grant insert,select on *.* to 'mysql_api'@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> grant proxy on mysql_dba@'%' to ''@'';
Query OK, 0 rows affected (0.00 sec)
mysql> grant proxy on mysql_dev@'%' to ''@'';
Query OK, 0 rows affected (0.00 sec)
mysql> grant proxy on mysql_api@'%' to ''@'';
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

If I login as hmcdaniel, it's effective user is not mysql_api which is wrong. The pam plugin failed to evaluate the "api developers" group:
mysql -u hmcdaniel
mysql> select user(), current_user(), @@proxy_user;
+---------------------+----------------+--------------+
| user() | current_user() | @@proxy_user |
+---------------------+----------------+--------------+
| hmcdaniel@localhost | @ | NULL |
+---------------------+----------------+--------------+
1 row in set (0.00 sec)

/var/log/secure gives more information on this:
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: User to match: hmcdaniel
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: Authentication string: dba=mysql_dba,developer=mysql_dev,api developers=mysql_api
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: Comparing group domain users with group in authenication string dba
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: Comparing group api developers with group in authenication string dba
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: Authentication string: developer=mysql_dev,api developers=mysql_api
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: Comparing group domain users with group in authenication string developer
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: Comparing group api developers with group in authenication string developer
Jul 31 03:08:01 9292447ef160 Percona PAM[594]: No group matches for user: hmcd...

I believe the issue is with line 74 of auth_mapping.c which ignores spaces for tokens. However, you can't just simply remove "!isspace(*ptr)" because if the authentication string has spaces, it won't be able to parse tokens properly:
Eg.
"dba=mysql_dba,developer=mysql_dev,api developers=mysql_api" //This would work
"dba=mysql_dba, developer=mysql_dev, api_developers=mysql_api" //This would no longer work
 74 while (*ptr && !isspace(*ptr) && *ptr != ',' && *ptr != '=')
 75 {
 76 ++token->token_len;
 77 ++ptr;
 78 }

https://github.com/percona/percona-server/pull/803
https://github.com/percona/percona-server/pull/804
https://github.com/percona/percona-server/pull/805

It is now possible to quote identifiers with double quotes. Example:

CREATE USER ''@'' IDENTIFIED WITH auth_pam AS 'mysqld, "data entry members" = data_entry, _developer="developer"';

I added debug messages for testing

This contains the changes I made to auth_mapping.c ti to add debug messages and stream it to syslog

Percona now uses JIRA for bug reports so this bug report is migrated to: https://jira.percona.com/browse/PS-1695