rlm_passwd(5) FreeRADIUS Module rlm_passwd(5)
rlm_passwd - FreeRADIUS Module
The rlm_passwd module provides authorization via files similar in for-
mat to /etc/passwd.
The lm_passwd module allows you to retrieve any account information
from any files with passwd-like format (/etc/passwd, /etc/group, smb-
passwd, .htpasswd, etc). Every field of the file may be mapped to a
RADIUS attribute, with one of the fields used as a key.
The module reads the file when it initializes, and caches the data in
memory. As a result, it does not support dynamic updates of the files
(the server has to be HUP'd), but it is very fast, even for files with
thousands of lines.
The configuration item(s):
The path to the file.
delimiter = ":"
The character to use as a delimiter between fields. The default
The size of the hashtable. If 0, then the passwords are not
cached and the passwd file is parsed for every request. We do
not recommend such a configuration. A larger hashsize means
less probability of collision and faster search in hashtable.
Having a hashsize in the range of 30-100% of the number of
passwd file records is reasonable.
If set to 'yes', and more than one record in file matches the
request, then the attributes from all records will be used. If
set to 'no' (the default) the module will warn about duplicated
If set to 'yes', then all records from the file beginning with
the '+' sign will be ignored. The default is 'no'.
format The format of the fields in the file, given as an example line
from the file, with the content of the fields as the RADIUS
attributes which the fields map to. The fields are seperated by
the ':' character.
The key field is signified by being preceded with a '*' character,
which indicates that the field has only one key, like the /etc/passwd
file. The key field may instead be preceded with '*,', which indicates
that the field has multiple possible keys, like the /etc/group file.
The other fields signify RADIUS attributes which, by default, are added
to the configuration items for a request.
To add an attribute to the request (as though it was sent by the NAS),
prefix the attribute name in the "format" string with the '~' charac-
To add an attribute to the reply (to be sent back to the NAS) prefix
the attribute name in the "format" string with the '=' character.
This configuration item defaults to "yes". If there is no value
for the attribute, then the attribute is not added. By setting
this value to "no", you can force the attribute to be added,
even if there is no value.
format = "My-Group:::*,User-Name"
Parse a file similar to the /etc/group file. An entry matches a
request when the name in a User-Name attribute exists in the
comma-seperated list of a line in the file. When an entry
matches, a "My-Group" attribute will be created and added to the
configuration items for the request. The value of that
attribute will be taken from the first field of the matching
line in the file.
The ":::" in the format string means that there are extra two
fields in the line, in between the group name and list of user
names. Those fields do not map to any RADIUS attribute, and are
For this example to work in practice, you will have to add the
My-Group attribute to the dictionary file. See the dictionary
manual page for details on how this may be done.
format = "~My-Group:::*,User-Name"
Similar to the previous entry, except the My-Group attribute is
added to the request, as though it was sent by the NAS.
radiusd(8), radiusd.conf(5) dictionary(5),
Alan DeKok <alandATfreeradius.org>
14 April 2004 rlm_passwd(5)