Hi, we're also facing the issue and yes not storing the certificate with TPM fixes the issue but we want to store certificates as secure as possible. We're troubleshooting this quite a time for now and we will patch the SSL part of freeRADIUS to write out all possible logs we can get to know which octet is invalid and also why. Hopefully we're able fix the issue on server site.

Windows WiFi profile was set to auto-join (non-interactive) Do you don't have the problem if you're using user-certificates and a interactive WiFi profile?

Built-in security measures control access to keys in that CSP, and it cannot be used non-interactively How have you verify it? We've played a little bit with the settings and anyhow the certificate is stored with TPM, the error occurs.

Just to reference, which certificates are you using? In your last post a SCEPman URL was visible in the logs. Have you tried other certificates which are stored with TPM? -- Lineconnect <quote author='Users mailing list'> 2 months later, a quick update on this topic (apologies, I may have broken the threading as I don't have a copy of the original e-mails any more!), just so there's an online reference here for anyone encountering the same error. Turns out I was wrong about it being Windows and OpenSSL getting muddled over TLS 1.2 vs. 1.3... To recap: Windows 10 clients, corporate WiFi network using EAP-TLS to RADIUS with machine certificate (SCEP) authentication only. Error in Freeradius logs: (6) eap_tls: ERROR: TLS Alert write:fatal:decrypt error tls: TLS_accept: Error in error (6) eap_tls: ERROR: Failed in __FUNCTION__ (SSL_read) (6) eap_tls: ERROR: error:0407E086:rsa routines:RSA_verify_PKCS1_PSS_mgf1:last octet invalid (6) eap_tls: ERROR: error:1417B07B:SSL routines:tls_process_cert_verify:bad signature (6) eap_tls: ERROR: System call (I/O) error (-1) (6) eap_tls: ERROR: TLS receive handshake failed during operation (6) eap_tls: ERROR: [eaptls process] = fail After encountering the error on a few machines again, even with "tls_max_version" set, I delved into the guts of Windows again, and found the error (which isn't helpful or descriptive) was actually caused because: * Some machine certificates had were stored/managed by the "Microsoft Platform Crypto Provider" (TPM-backed) * Built-in security measures control access to keys in that CSP, and it cannot be used non-interactively * Windows WiFi profile was set to auto-join (non-interactive) * Windows couldn't get the key, so $deity knows what signature it was sending * OpenSSL rightly got confused The solution: Ensure machine certificate keys are stored in the "Microsoft Software Key Storage Provider" (or another CSP/KSP that permits non-interactive use). All is well again, and I'm close to shutting down NPS :-) -- Peter Bance Information Security Adviser Alan DeKok wrote:

A final update on this, in case anyone here's interested (or to "wrap up" for anyone stumbling across this thread online) - I fixed it, and Windows clients are now happily joining WiFi. It's a beautiful thing to behold :-)

In the end, I had to force OpenSSL on FreeRADIUS to stop offering TLS1.3 ciphers using the mods/eap config:

tls_max_version = "1.2"

Good to hear.

It seems there may be a bug in OpenSSL 1.1.1 such that even though the negotiation resulted in a TLS 1.2 session, the weird back-port of TLS 1.3 ciphers into TLS 1.2 confused things (a lot), and it tried checking for TLS 1.3 style signatures inappropriately.

Weird, but OK. It's OpenSSL :( Alan DeKok. - List info/subscribe/unsubscribe? See http://www.freeradius.org/list/users.html </quote> Quoted from: http://freeradius.1045715.n5.nabble.com/RE-EAP-TLS-Signature-Check-Failure-t... _____________________________________ Sent from http://freeradius.1045715.n5.nabble.com