...
A common question regarding this definition is: "why is TLS also configured? I don't want it, can I disable it?" The answer is: the TTLS and PEAP sections depend on the tls stanza for the definition of which server certificates to use. You cannot delete the stanza, but that doesn't mean you can't effectively disable TLS: the tls stanza contains the ca_file parameter. Only clients with a TLS client certificate from this CA will be accepted. We have just created a brand-new CA with the "bootstrap" script. Simply don't issue nor distribute any client certificates from this CA, then nobody will be able to log in with EAP-TLS.
Another question is regarding the mschapv2 section. For all practical purposes, the easy answer is that it is a piece of magic and needs to be there for PEAP to work. If you are curious regarding the gory details, please let us know.
Note that one parameter for both the ttls and peap stanza is "virtual_server = eduroam-inner-tunnel". This means that the inner EAP authentication will be carried out in this other virtual server, which we will define later.
Virtual server eduroam: enable EAP
Compared to the eduroam SP config, you simply need to additionally mention the "eap" module in both the authorize and authenticate stanza of the file /etc/raddb/sites-enabled/eduroam. It will then look like the following:
| Code Block |
|---|
authorize {
auth_log
suffix
eap
}
authenticate {
eap
}
|
Virtual server eduroam-inner-tunnel
When the eap module has started with an authentication, it will first establish a TLS tunnel; this is done by enabling the module in the previous "eduroam" virtual server. After the TLS tunnel is established, the content (i.e. the tunneled authentication) is processed separately in this new virtual server. Create the file in /etc/raddb/sites-enabled/eduroam-inner-tunnel and give it the following content:
| Code Block |
|---|
server eduroam-inner-tunnel {
authorize {
auth_log
eap
files
mschap
pap
}
authenticate {
Auth-Type PAP {
pap
}
Auth-Type MS-CHAP {
mschap
}
eap
}
post-auth {
reply_log
Post-Auth-Type REJECT {
reply_log
}
}
}
|
Let's revisit the modules which this virtual server executes one after another:
- auth_log: logs the incoming packet to the file system. This is needed to fulfill the eduroam SP logging requirements. Note that this log *may* contain the user's cleartext password if TTLS-PAP is used. You can log the packet with omitted User-Password attribute if you prefer; see the "Goodies" section for more details).
- eap: if the EAP authentication contains another EAP instance inside, the module will decode it. This is the case for PEAP.
- files: this module tries to find out the authoritative password for the user by looking up the username in the file
- mschap: this module is in effect only if PEAP-MSCHAPv2 or TTLS-MSCHAPv2 is used. It will mark the packet as to be authenticated with MS-CHAP algorithms later.
- pap: this module is in effect only if TTLS-PAP is used. It will mark the packet as to be authenticated with PAP alogrithms later.
- reply_log: logs the reply packet to the file system
User database: flat file
By default, the "files" module will use information in the file
| Code Block |
|---|
/etc/raddb/users
|
for authenticating users. This file has a straightforward format
| Code Block |
|---|
icecold@group1.aq Cleartext-Password := "snowwhite"
otheruser@group1.aq Cleartext-Password := "swordfish"
|
Local authentication for your realm
In the SP configuration, all requests were unconditionally forwarded to upstream. We will need to revisit the file "proxy.conf" and mark one realm to NOT proxy. In this example, we will use "@group1.aq" as the local authentication realm. Simply add the following stanza immediately preceeding the "DEFAULT" realm:
| Code Block |
|---|
realm group1.aq {
nostrip
}
|
Since the stanza doesn't contain a server pool to proxy to, this realm won't be proxied and instead authenticated locally. This stanza works only for users who correctly use the full username format "user123@group1.aq" for their eduroam login.
Note that in newer versions of FreeRADIUS (>3.0.14) there is a new tls-config section that allows you to configure the common TLS configuration without configuring the TLS EAP type. The config above is backwards compatable, but if you want to take advantage of the new section you can replace the name of the "tls" block above with "tls-config tls-common" and then reference it from each EAP type with "tls = tls-common" (the example eap config shows you how to do this).
Another question is regarding the mschapv2 section. For all practical purposes, the easy answer is that it is a piece of magic and needs to be there for PEAP to work. If you are curious regarding the gory details, please let us know.
Note that one parameter for both the ttls and peap stanza is "virtual_server = eduroam-inner-tunnel". This means that the inner EAP authentication will be carried out in this other virtual server, which we will define later.
Virtual server eduroam: enable EAP, make Operator-Name conditional
Compared to the eduroam SP config, you need to additionally mention the "eap" module in both the authorize and authenticate stanza of the file /etc/raddb/sites-enabled/eduroam so that your server can process EAP requests from your own userbase.
You should also make sure to only tag those incoming requests with the Operator-Name attribute which actually originate from your own WiFi gear - as an IdP, your own users roaming elsewhere will also be processed, but they should not carry your own Operator-Name. For the purposes of this wiki, let's assume that you are connected to one FLR server, and it is defined in your clients.conf with the shortname "antarctica-flr-1" (see below for the exact definition).
It will then look like the following:
| Code Block |
|---|
authorize {
if ("%{client:shortname}" != "antarctica-flr-1") {
update request {
Operator-Name := "1yourdomain.tld"
# the literal number "1" above is an important prefix! Do not change it!
}
}
auth_log
suffix
eap
}
authenticate {
eap
}
|
Virtual server eduroam-inner-tunnel
When the eap module has started with an authentication, it will first establish a TLS tunnel; this is done by enabling the module in the previous "eduroam" virtual server. After the TLS tunnel is established, the content (i.e. the tunneled authentication) is processed separately in this new virtual server. Create the file in /etc/raddb/sites-enabled/eduroam-inner-tunnel and give it the following content:
| Code Block |
|---|
server eduroam-inner-tunnel {
authorize {
auth_log
eap
files
mschap
pap
}
authenticate {
Auth-Type PAP {
pap
}
Auth-Type MS-CHAP {
mschap
}
eap
}
post-auth {
reply_log
Post-Auth-Type REJECT {
reply_log
}
}
}
|
Let's revisit the modules which this virtual server executes one after another:
- auth_log: logs the incoming packet to the file system. This is needed to fulfill the eduroam SP logging requirements. Note that this log *may* contain the user's cleartext password if TTLS-PAP is used. You can log the packet with omitted User-Password attribute if you prefer; see the "Goodies" section for more details).
- eap: if the EAP authentication contains another EAP instance inside, the module will decode it. This is the case for PEAP.
- files: this module tries to find out the authoritative password for the user by looking up the username in the file
- mschap: this module is in effect only if PEAP-MSCHAPv2 or TTLS-MSCHAPv2 is used. It will mark the packet as to be authenticated with MS-CHAP algorithms later.
- pap: this module is in effect only if TTLS-PAP is used. It will mark the packet as to be authenticated with PAP alogrithms later.
- reply_log: logs the reply packet to the file system
User database: flat file
By default, the "files" module will use information in the file
| Code Block |
|---|
/etc/raddb/users
|
for authenticating users. This file has a straightforward format
| Code Block |
|---|
icecold@group1.aq Cleartext-Password := "snowwhite"
otheruser@group1.aq Cleartext-Password := "swordfish"
|
Local authentication for your realm
In the SP configuration, all requests were unconditionally forwarded to upstream. We will need to revisit the file "proxy.conf" and mark one realm to NOT proxy. In this example, we will use "@group1.aq" as the local authentication realm. Simply add the following stanza immediately preceeding the "DEFAULT" realm:
| Code Block |
|---|
realm group1.aq {
nostrip
}
|
Since the stanza doesn't contain a server pool to proxy to, this realm won't be proxied and instead authenticated locally. This stanza works only for users who correctly use the full username format "user123@group1.aq" for their eduroam login.
If the IdP and SP are colocated, it is possible to *locally* also accept users who erronuously omitted their realm (just "user123"). This is NOT permitted by the eduroam policy (read 6.3.2 bullet 6 under AAA Servers of the current service definition document: "The outer EAP identities (and with it, RADIUS User-Name attributes) for the IdP MUST be in the format of arbitrary@realm"). Allowing this also requires further configuration and it is strongly discouraged, because it will give such users a "halfways-working" experience: they will be able to use eduroam when on their own IdP's campus, because no routing information needs to be evaluated, but their account will If the IdP and SP are colocated, it is possible to *locally* also accept users who erronuously omitted their realm (just "user123"). This requires further configuration, but it is strongly discouraged, because it will give such users a "halfways-working" experience: they will be able to use eduroam when on their own IdP's campus, because no routing information needs to be evaluated, but their account will fail at all other locations. Therefore, this guide does not include instructions for that kind of setup.
Processing incoming requests
As an eduroam IdP, your users can go to other eduroam hotspots around the globe. They will still be authenticated at your server. In these roaming cases, your upstream FLR servers will send Access-Requests to your server. Surprisingly, it is very simple to configure that: these upstream servers are simply clients - just like an Access Point. So, simply add client stanzas for your FLR servers into clients.conf:
Processing incoming requests
As an eduroam IdP, your users can go to other eduroam hotspots around the globe. They will still be authenticated at your server. In these roaming cases, your upstream FLR servers will send Access-Requests to your server. Surprisingly, it is very simple to configure that: these upstream servers are simply clients - just like an Access Point. So, simply add client stanzas for your FLR servers into clients.conf:
| Code Block |
|---|
client antarctica-flr-1 {
ipaddr = 172.20.1.2
netmask = 32
secret = secretstuff
require_message_authenticator = yes
shortname = antarctica-flr-1
nastype = other
virtual_server = eduroam
}
|
CUI for eduroam IdP
To use the Chargeable-User-Identity (CUI) you must already use the Operator-Name attribute. This documentation is only for FreeRADIUS 3.0.X release.
Modify the log module
Edit "eduroam_cui_log" file in the mods-available/ subdirectory and add the following lines to your virtual inner server :
| Code Block |
|---|
...
linelog cui_inner_log {
# filename = syslog
filename = ${logdir}/radius.log
format = ""
reference = "inner_auth_log.%{%{reply:Packet-Type}:-format}"
inner_auth_log {
Access-Accept = "%t : eduroam-inner-auth#VISINST=%{request:Operator-Name}#USER=%{User-Name}#CSI=%{%{Calling-Station-Id}:-Unknown Caller Id}#NAS=%{%{Called-Station-Id}:-Unknown Access Point}#CUI=%{%{%{reply:Chargeable-User-Identity}:-%{outer.reply:Chargeable-User-Identity}}:-Local User}#RESULT=OK#"
Access-Reject = "%t : eduroam-inner-auth#VISINST=%{request:Operator-Name}#USER=%{User-Name}#CSI=%{%{Calling-Station-Id}:-Unknown Caller Id}#NAS=%{%{Called-Station-Id}:-Unknown Access Point}#CUI=%{%{%{reply:Chargeable-User-Identity}:-%{outer.reply:Chargeable-User-Identity}}:-Local User}#RESULT=FAIL#"
}
} |
Use policy and module in your eduroam-inner-tunnel virtual server
Add 'cui-inner' (policy already defined, you don't need to change it) and 'cui_inner_log' in post-auth section :
| Code Block |
|---|
server eduroam-inner-tunnel {
...
post-auth {
reply_log
cui_inner_log
cui-inner
Post-Auth-Type REJECT {
reply_log
cui_inner_log
}
}
...
} |
| Code Block |
client antarctica-flr-1 {
ipaddr = 172.20.1.2
netmask = 32
secret = secretstuff
require_message_authenticator = no
shortname = antarctica-flr-1
nastype = other
virtual_server = eduroam
}
|
That's it! Now your server is prepared for eduroam IdP operation! You can add users to your "database" by amending the "users" file; if you do, you will unfortunately have to restart FreeRADIUS so that it picks up the change.
...