EAP-TLS without client authentication
This may sound like a strange request, but I'd like to know if it is possible to use FreeRADIUS to perform EAP-TLS without asking for a client certificate. The purpose is to allow for a secure connection to an access point without client authentication. I think this might be useful to replace "open wireless" for public wireless access with something more secure. According to the EAP-TLS RFC (rfc2716), it sounds like it might be possible: "The certificate_request message is included when the server desires the client to authenticate itself via public key. While the EAP server SHOULD require client authentication, this is not a requirement, since it may be possible that the server will require that the peer authenticate via some other means." I tried this with FreeRADIUS and eapol_test (from wpa_supplicant) with the following result: [eap] Identity does not match User-Name, setting from EAP Identity. [eap] Failed in handler ++[eap] returns invalid Failed to authenticate the user. The only change I've made from the default eap.conf is to try disabling the CA_file setting (I've tried it both ways). Does it sound like this is something that should be possible, or am I off base? Thanks! Christopher
This may sound like a strange request, but I'd like to know if it is possible to use FreeRADIUS to perform EAP-TLS without asking for a client certificate. The purpose is to allow for a secure connection to an access point without client authentication.
EAP has nothing to do with "secure connection to an access point". That's what WPA is for. Ivan Kalik Kalik Informatika ISP
In trying to be brief for the list, I realize now that I oversimplified my question. What I am looking for a way to replace open, clear text WiFi at public hotspots (and possibly newly installed home WiFi routers) with something more secure. As you know, open WiFi presents security risks to the users and the operators. While WPA and WPA2 does provide for data-link encryption, it needs keying material to encrypt the communication. It can use a pre-shared key (PSK) for this purpose, but this has the drawbacks of communicating the key to the user and configuration on the end users part. Perhaps more seriously in a public access scenario it doesn't help, as you are giving the public the key which would by definition allow an attacker access to the keying material. That's where WPA-Enterprise comes in, with it's support for 802.1x and EAP. In "A secure Wireless LAN hotspot for anonymous users" (http://blogs.zdnet.com/Ou/?p=587), George Ou proposed that public access wireless operators could use WPA-Enterprise with PEAPv0/MSCHAPv2 and a well known username and password combination such as guest/guest. Because PEAP uses TLS, the keying material is sent securely from the RADIUS server to the client, even if the client side authentication is well known. The two downsides of this approach is similar to PSKs, in that you have to have a mechanism to communicate the configuration information, and the configuration is burdensome on the user. I have proposed this solution to hotspot operators whom, after testing, have rejected it as too difficult for the user. When thinking about George's proposed solution, I considered that WPA-Enterprise would be useful for these hotspots if we could use a EAP method that authenticates the identity of the server and provides for secure transfer of the keying material to the client without requiring the client to authenticate itself. RFC 5216 "The EAP-TLS Authentication Protocol" (http://www.ietf.org/rfc/rfc5216.txt) has clarified that it is not mandatory that the EAP server require peer authentication: "The certificate_request message is included when the server desires the peer to authenticate itself via public key. While the EAP server SHOULD require peer authentication, this is not mandatory, since there are circumstances in which peer authentication will not be needed (e.g., emergency services, as described in [UNAUTH]), or where the peer will authenticate via some other means." It seems that because the RFC does not require EAP-TLS to authenticate the client, it could provide that mechanism if there were a RADIUS server that supported EAP-TLS without client authentication. Obviously FreeRADIUS seems ideal for this purpose because of it's GPLv2 license, community support, and wide acceptance. Of course this will also rely on the popular 802.1x supplicants supporting the same. I plan on testing the client supplicant piece after setting up a server that can handle EAP-TLS without client certificate authentication. Hopefully it could be configured natively to do so, or with code changes if necessary. Thanks for your help! Christopher Byrd On Thu, Jan 8, 2009 at 4:00 AM, <tnt@kalik.net> wrote:
This may sound like a strange request, but I'd like to know if it is possible to use FreeRADIUS to perform EAP-TLS without asking for a client certificate. The purpose is to allow for a secure connection to an access point without client authentication.
EAP has nothing to do with "secure connection to an access point". That's what WPA is for.
Ivan Kalik Kalik Informatika ISP
- List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html
While WPA and WPA2 does provide for data-link encryption, it needs keying material to encrypt the communication. It can use a pre-shared key (PSK) for this purpose, but this has the drawbacks of communicating the key to the user and configuration on the end users part.
So they don't want PSK.
The two downsides of this approach is similar to PSKs, in that you have to have a mechanism to communicate the configuration information, and the configuration is burdensome on the user. I have proposed this solution to hotspot operators whom, after testing, have rejected it as too difficult for the user.
And configuring something that Microsoft calls Zero Configuration is too complicated. Use captive portal then. Ivan Kalik Kalik Informatika ISP
Christopher Byrd wrote:
What I am looking for a way to replace open, clear text WiFi at public hotspots (and possibly newly installed home WiFi routers) with something more secure.
This is network layer security.
That's where WPA-Enterprise comes in, with it's support for 802.1x and EAP.
Yes. EAP provides keying material.
In "A secure Wireless LAN hotspot for anonymous users" (http://blogs.zdnet.com/Ou/?p=587), George Ou proposed that public access wireless operators could use WPA-Enterprise with PEAPv0/MSCHAPv2 and a well known username and password combination such as guest/guest. Because PEAP uses TLS, the keying material is sent securely from the RADIUS server to the client, even if the client side authentication is well known.
That's marketing nonsense. Don't believe random garbage you read on industry web sites.
The two downsides of this approach is similar to PSKs, in that you have to have a mechanism to communicate the configuration information, and the configuration is burdensome on the user. I have proposed this solution to hotspot operators whom, after testing, have rejected it as too difficult for the user.
I spend a fair amount of time working with WiFi operators && telecommunications companies. None of them will do EAP unless it's easy for their end users.
When thinking about George's proposed solution, I considered that WPA-Enterprise would be useful for these hotspots if we could use a EAP method that authenticates the identity of the server and provides for secure transfer of the keying material to the client without requiring the client to authenticate itself. RFC 5216 "The EAP-TLS Authentication Protocol" (http://www.ietf.org/rfc/rfc5216.txt) has clarified that it is not mandatory that the EAP server require peer authentication:
Ignore George's blog. It's marketing material. It has little to no relevance for operators running real networks.
"The certificate_request message is included when the server desires the peer to authenticate itself via public key. While the EAP server SHOULD require peer authentication, this is not mandatory, since there are circumstances in which peer authentication will not be needed (e.g., emergency services, as described in [UNAUTH]), or where the peer will authenticate via some other means."
Emergency services are being removed from many network access standards. That use is being abused, and isn't useful.
It seems that because the RFC does not require EAP-TLS to authenticate the client,
It does. The only time the client isn't being authenticated is via mechanisms that aren't implement, aren't supported, and are being deprecated.
it could provide that mechanism if there were a RADIUS server that supported EAP-TLS without client authentication. Obviously FreeRADIUS seems ideal for this purpose because of it's GPLv2 license, community support, and wide acceptance.
Operators will not agree to this.
Of course this will also rely on the popular 802.1x supplicants supporting the same. I plan on testing the client supplicant piece after setting up a server that can handle EAP-TLS without client certificate authentication. Hopefully it could be configured natively to do so, or with code changes if necessary.
Supplicants do not currently support this. I know all of the major supplicant vendors, and I doubt very much this functionality will go in. Perhaps you could describe what the *problem* is in more detail. Talking about specific solutions often results in the discussion getting bogged down in details about why it won't work that way. As background, many operators are looking into moving to 802.1x everywhere. If it's supported on their home networks, then their users will have it configured, and it will (usually) work on visited networks, too. Alan DeKok.
Hi, Another approach you may wish to try is using the hotspot firmware on the hotspot router to help you in conjunction with the freeradius server. Coovachilli seems to have a solution, based on freeradius, jradius and coovachilli (maintained branch of chillispot, as I understand). Have a look here http://coova.org/wiki/index.php/CoovaChilli/WithWPACaptivePortal whether that is what you are looking for. Cheers Hanno Schupp -----Original Message----- From: Alan DeKok [mailto:aland@deployingradius.com] Sent: Friday, 9 January 2009 10:00 a.m. To: FreeRadius users mailing list Subject: Re: EAP-TLS without client authentication Christopher Byrd wrote:
What I am looking for a way to replace open, clear text WiFi at public hotspots (and possibly newly installed home WiFi routers) with something more secure.
This is network layer security.
That's where WPA-Enterprise comes in, with it's support for 802.1x and EAP.
Yes. EAP provides keying material.
In "A secure Wireless LAN hotspot for anonymous users" (http://blogs.zdnet.com/Ou/?p=587), George Ou proposed that public access wireless operators could use WPA-Enterprise with PEAPv0/MSCHAPv2 and a well known username and password combination such as guest/guest. Because PEAP uses TLS, the keying material is sent securely from the RADIUS server to the client, even if the client side authentication is well known.
That's marketing nonsense. Don't believe random garbage you read on industry web sites.
The two downsides of this approach is similar to PSKs, in that you have to have a mechanism to communicate the configuration information, and the configuration is burdensome on the user. I have proposed this solution to hotspot operators whom, after testing, have rejected it as too difficult for the user.
I spend a fair amount of time working with WiFi operators && telecommunications companies. None of them will do EAP unless it's easy for their end users.
When thinking about George's proposed solution, I considered that WPA-Enterprise would be useful for these hotspots if we could use a EAP method that authenticates the identity of the server and provides for secure transfer of the keying material to the client without requiring the client to authenticate itself. RFC 5216 "The EAP-TLS Authentication Protocol" (http://www.ietf.org/rfc/rfc5216.txt) has clarified that it is not mandatory that the EAP server require peer authentication:
Ignore George's blog. It's marketing material. It has little to no relevance for operators running real networks.
"The certificate_request message is included when the server desires the peer to authenticate itself via public key. While the EAP server SHOULD require peer authentication, this is not mandatory, since there are circumstances in which peer authentication will not be needed (e.g., emergency services, as described in [UNAUTH]), or where the peer will authenticate via some other means."
Emergency services are being removed from many network access standards. That use is being abused, and isn't useful.
It seems that because the RFC does not require EAP-TLS to authenticate the client,
It does. The only time the client isn't being authenticated is via mechanisms that aren't implement, aren't supported, and are being deprecated.
it could provide that mechanism if there were a RADIUS server that supported EAP-TLS without client authentication. Obviously FreeRADIUS seems ideal for this purpose because of it's GPLv2 license, community support, and wide acceptance.
Operators will not agree to this.
Of course this will also rely on the popular 802.1x supplicants supporting the same. I plan on testing the client supplicant piece after setting up a server that can handle EAP-TLS without client certificate authentication. Hopefully it could be configured natively to do so, or with code changes if necessary.
Supplicants do not currently support this. I know all of the major supplicant vendors, and I doubt very much this functionality will go in. Perhaps you could describe what the *problem* is in more detail. Talking about specific solutions often results in the discussion getting bogged down in details about why it won't work that way. As background, many operators are looking into moving to 802.1x everywhere. If it's supported on their home networks, then their users will have it configured, and it will (usually) work on visited networks, too. Alan DeKok.
participants (4)
-
Alan DeKok -
Christopher Byrd -
Hanno Schupp -
tnt＠kalik.net