On Jan 4, 2026, at 11:16 PM, Dennis Bland <dennis@dbperformance.com> wrote:
I've compiled/installed FreeRADIUS 3.2.8 on Ubuntu 24.04 (Linux 6.8.0 and OpenSSL 3.0.13), and it gives the attached "MS-CHAP2 Response is incorrect" error during inner tunnel negotiation in Phase 0 (PAC file creation) of EAP-FAST. Upgrading the Linux kernel to 6.16 and OpenSSL 3.0.16 gives the same result. Compiling the latest FreeRADIUS 3.2.x branch head (3.2.9 dev) as of a few days ago also gives the same result.
Hmm... OK. I just tried it, I'm seeing the same thing. I'm not sure what changed.
Note that EAP-PEAP/MSCHAPV2 works fine (log also attached) on the identical supplicant / authenticator / authentication server platform.
Unfortunately, PEAP is infinitely simpler than EAP-FAST.
The supplicant is also on a Ubuntu 24.04 platform (OpenSSL 3.0.13), running the latest snapshot of wpa_supplicant, and TLS 1.3 has been confirmed working with EAP-PEAP when tls_max is set to 1.3 in FreeRADIUS on the authentication server.
Yes. PEAP has been updated for TLS 1.3: https://www.rfc-editor.org/rfc/rfc9427.html EAP-FAST was also updated for TLS 1.3, but 3.2.x doesn't support that yet. In part because the major supplicants don't support it.
Background: Recent Ubuntu versions have forcibly disabled TLS 1.0 and TLS 1.1, and EAP-FAST support with TLS 1.2 was first introduced in FreeRADIUS 3.2.8. However, the FreeRADIUS package version bundled with Ubuntu 24.04 is version 3.2.5, and version 3.2.7 with Ubuntu 25.10. This unfortunately leaves a gap in EAP-FAST support. Until a newer FreeRADIUS package is available on Ubuntu, compiling the 3.2.8 source seems to be the only option in order to support BOTH TLS 1.3 with EAP-PEAP and TLS 1.2 with EAP-FAST.
It's apparently hard for Ubuntu to use a version of FreeRADIUS which was released in the last few years. <sigh> If you want updated packages, you can get update packages from: https://packages.inkbridgenetworks.com/. They're free, and up to date.
Any further troubleshooting suggestions? From reading the mailing list archives, I've seen this EAP-FAST issue pop up a few times in the past on earlier 3.0.x versions, but with no resolution.
Try the updated packages as above. But until I have time for some more in-depth testing, I'm not sure what's going on. A quick check shows the same issue, even when TLS 1.1 is used. If you have a little bit of time to spare, perhaps try the EAP-FAST tests using various versions of the server. I know it worked at one point, so I don't know why or when it stopped working. Alan DeKok.