On 11/07/17 17:21, Federico Capoano wrote: > Hi everyone, > Hi Federico,
I have looked into FreeRadius (FR) in the past, so I am curious about this issue. > I have found a possible solution for the hash algorithm, let's recap > for those who don't know what we are talking about. > > *Problem* > > Freeradius many different authorization and authentication schemes but > when it comes to the hashing algorithm used for passwords choices are > limited, the stronger hashing algorithms being md5, sha1 and unix crypt. What is exactly the hash you are referring to? If I understood correctly it is the hash used to encrypt passwords in the database, which is not mandated by FR but from the (inner) method you configure FR to use: http://deployingradius.com/documents/protocols/compatibility.html basically, if you want to use any of these authentication protocols, you have to use these hashes because the password comes already hashed from the supplicant. If you want to use another hash you have to configure FR to pass along the password in clear, and then do your own hashing. You can do this using the PAP protocol, which sends the password in clear (!!) and then you can hash it at the destination. To make this reasonably secure you have to embed it into a TTLS tunnel. This may be even supported by other applications so you can re-use the db for other uses. > > Unfortunately these algorithms are rather obsolete and we would much > rather let Django handle this for us because it does it pretty well . > Django nowadays uses PBKDF2 <https://en.wikipedia.org/wiki/PBKDF2> by > default and allows for even stronger algorithms, see the Password > Management > <https://docs.djangoproject.com/en/dev/topics/auth/passwords/> > documentation on the django website for more information. > > To use the default freeradius setup would mean downgrading our own > hashing algorithm and I think this is unacceptable for several reasons: > > * it's 2017, MD5 is easy to break and SHA1 has just been > demonstrated to be crackable by Google and other big players > * we really didn't like that in OpenWISP1 each module has its own > database of users, infact we hated it; > our aim is to have a single (distributed) database of users shared > between the different openwisp2 modules and we really want > django-freeradius to become an important module of openwisp2, > therfore downgrading the hashing algorithm for django-freeradius > means downgrading it for the entire openwisp2 ecosystem: > definitely not viable! > > *Solution* > * > * > The recommended solution in these cases is to delegate authorization > and authentication to a separate application, in our case this can be > handled by django-freeradius itself. > > *rlm_exec* > > The first solution I have tried is to configure freeradius 3 to use > the *exec* module call a unix/linux script during the authorization > phase, the script gets passed the username and password and if the > combination is correct exits with 0 (zero) otherwise it exits with 1 > (which means failure). > This solution works but has two problems: > > * freeradius runs as a user (freerad in my test environment) which > has very limited permissions and can't easily access the python > virtualenv of django-freeradius, infact I had to perform some ugly > hacks to make this script work > * this method is not recommended by the freeradius community because > according to them it doesn't scale well, they suggest to use the > *rlm_rest* module > > *rlm_rest* > * > * > This module allows to configure freeradius to delegate some or all of > its operations (authorization, authentication, accounting, postauth) > to a REST API. > > I've successfully configured my test freeradius instance to > authenticate and authorize using an existing REST API and it seems to > work very well. > > Since this method is recommended by the freeradius community and > allows great flexibility, I believe we should go along this path: we > should implement a few simple API endpoints that are dedicated to > freeradius, starting with authorize. Again, if I understood well, you are actually giving FR an API that plugs back into django? then, why are you using FR at all? I suppose your use case is to have one FR instance that serves several services, such as openwisp, but this way you can't decouple FR from django. best, leonardo. -- Leonardo Maccari, Assistant Professor @DISI, University of Trento Tel: +39 0461 285323, www.disi.unitn.it/~maccari, gpg ID: AABE2BD7 -- You received this message because you are subscribed to the Google Groups "OpenWISP" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
