[Dovecot] comment on dovecot documentation on PAM

[president at irithm.com]

Dear Dovecote devotees,

I have been going through dovecot configuration for the 
first time. I am not an experienced systems administrator
so I had to do a left turn to read up about PAM while
doing all the configuration for my new webmail service.
 
I found that the writing in the dovecot documentation about
PAM to be rather misleading in at least one aspect. 
The documentation I am specifically referring to is at
http://wiki.dovecot.org/Authentication?highlight=%28authentication%29
and in the comments found in the dovecot.conf file.
In this documentation PAM is referred to as a password database.
It appears that is not correct, rather PAM is something
that uses a password database. 

Since the default for  "auth_passdb" given in dovecot.conf was
"pam" I spent sometime trying to find a pam password database.
I eventually found out at an independent website that what pam 
uses is either /etc/passwd or /etc/shadow or /etc/samba/smbpasswd. 
It was a relief to find out pam uses one of these, since
my system has one of them (/etc/shadow), but I was looking to 
find something quite different for pam since /etc/shadow is 
one of the listed alternative values for "auth_passdb". 

I would have been spared a somewhat lengthy search to find out 
this information if the documentation was written rather more 
clearly. So, to help others, I suggest changing the following
lines in dovecot.conf 

# Where password database is kept:
#   passwd: /etc/passwd or similiar, using getpwnam()
#   shadow: /etc/shadow or similiar, using getspnam()
#   pam [<service> | *]: PAM authentication

to:

# Where password database is kept:
#   passwd: /etc/passwd or similiar, using getpwnam()
#   shadow: /etc/shadow or similiar, using getspnam()
#   pam [<service> | *]: /etc/shadow or similiar, using PAM
authentication


Updating the documentation in 
http://wiki.dovecot.org/Authentication?highlight=%28authentication%29
to include a phrase that mentions that PAM authentication 
works from one of the standard password databases (i.e. /etc/passwd, 
/etc/shadow or /etc/samba/smbpasswd) would also be helpful.

yours sincerely,

Rolf