Solved: After Upgrade from freeradius 2 to 3 (Debian 8 - 9): TLS Alert write:fatal:unsupported certificate
Gladewitz, Robert
Robert.Gladewitz at dbfz.de
Wed Jan 24 08:16:39 CET 2018
I would like to summarize the topic for FreeRadius.
The error discussed is actually due to a change in OpenSSL1.1. My request in the OpenSSL user group on this topic has led to a controversial discussion.
Of course the certificates are RFC compliant. Unfortunately, OpenSSL does not evaluate the ExtendedKeyUsage (eku) as defined in the RFC in question.
In the case discussed here, ExtednedKeyUsage (eku) is set to TLS "Web Server Authentication" for the CA (CAPF) certificate.
This would be allowable under RFC, but is not allowed by the openssl client certificate validation functions.
The background: An eku is evaluated in a CA so that only these defined extensions can be used, if it is defined. If no EKU is defined, there are no restrictions. This means I would need to add either "TLS WEB Client Authentification" or delete "TLS WEB Server Authentification".
The solution for us was, that we changed the csr and removed the ExtendedKeyUsage "TLS Web Server Authentification". So the Cisco CUCM got the CAPF with the eku and the radius of one without any eku.
Unfortunately, this is not a solution for customers who use the certificate signed by Cisco CallManagers themselves, as the eku for the freeradius can not simply be deleted here. This means, that there is no chance to authenticate the phones with a freeradius version based on openssl libraries> = 1.1.0 - at least not with tls.
Remedy would only create a correctly patched openssl version or the correct implementation of an openssl_verify function (as discussed in openssl thread).
But as Alan had said defiantly, then the affected but the Cisco ACS / ISE take.
Robert
-----Ursprüngliche Nachricht-----
Von: Gladewitz, Robert
Gesendet: Freitag, 19. Januar 2018 11:40
An: Gladewitz, Robert <Robert.Gladewitz at dbfz.de>; FreeRadius users mailing list <freeradius-users at lists.freeradius.org>
Betreff: AW: After Upgrade from freeradius 2 to 3 (Debian 8 - 9): TLS Alert write:fatal:unsupported certificate
I forget a higher debuglevel. What mean:
in __FUNCTION__ (SSL_read): ../ssl/statem/statem_srvr.c[2896]:error:1417C086:SSL routines:tls_process_client_certificate:certificate verify failed
???
<SNIP>
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: Continuing EAP-TLS
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: Peer sent flags --L
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: Peer indicated complete TLS record size will be 1432 bytes
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: Got complete TLS record (1432 bytes)
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: [eaptls verify] = length included
Fri Jan 19 11:35:32 2018 : Debug: Ignoring cbtls_msg call with pseudo content type 256, version 0
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: TLS_accept: SSLv3/TLS write server done
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: <<< recv TLS 1.0 Handshake [length 03c2], Certificate
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: Creating attributes from certificate OIDs
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: TLS-Cert-Serial := "1009"
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: TLS-Cert-Expiration := "380111125719Z"
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: TLS-Cert-Subject := "/C=DE/ST=Sachsen/L=Leipzig/O=DBFZ Deutsches Biomasseforschungszentrum gGmbH/OU=IT/CN=CAPF-91d43ef6"
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: TLS-Cert-Issuer := "/C=DE/ST=Sachsen/L=Leipzig/O=DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH/OU=IT/CN=DBFZ CA INTERN ROOT/emailAddress=support at dbfz.de"
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: TLS-Cert-Common-Name := "CAPF-91d43ef6"
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap_tls: SSL says error 26 : unsupported certificate purpose
Fri Jan 19 11:35:32 2018 : Debug: Ignoring cbtls_msg call with pseudo content type 256, version 0
Fri Jan 19 11:35:32 2018 : Debug: (3) eap_tls: >>> send TLS 1.0 Alert [length 0002], fatal unsupported_certificate
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap_tls: TLS Alert write:fatal:unsupported certificate
Fri Jan 19 11:35:32 2018 : Error: tls: TLS_accept: Error in error
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap_tls: Failed in __FUNCTION__ (SSL_read): ../ssl/statem/statem_srvr.c[2896]:error:1417C086:SSL routines:tls_process_client_certificate:certificate verify failed
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap_tls: System call (I/O) error (-1)
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap_tls: TLS receive handshake failed during operation
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap_tls: [eaptls process] = fail
Fri Jan 19 11:35:32 2018 : ERROR: (3) eap8021xciscophone: Failed continuing EAP TLS (13) session. EAP sub-module failed
</SNIP>
-----Ursprüngliche Nachricht-----
Von: Freeradius-Users [mailto:freeradius-users-bounces+robert.gladewitz=dbfz.de at lists.freeradius.org] Im Auftrag von Gladewitz, Robert via Freeradius-Users
Gesendet: Freitag, 19. Januar 2018 10:28
An: freeradius-users at lists.freeradius.org
Betreff: AW: After Upgrade from freeradius 2 to 3 (Debian 8 - 9): TLS Alert write:fatal:unsupported certificate
Hello,
in first discusion, the errors seems tob e on a wrong ca certificate. Now, all certifices a changed an the errror still happening:
<SNIP: DEBUG>
(69) eap_tls: Continuing EAP-TLS
(69) eap_tls: Peer indicated complete TLS record size will be 1432 bytes
(69) eap_tls: Got complete TLS record (1432 bytes)
(69) eap_tls: [eaptls verify] = length included
(69) eap_tls: TLS_accept: SSLv3/TLS write server done
(69) eap_tls: <<< recv TLS 1.0 Handshake [length 03c2], Certificate
(69) eap_tls: Creating attributes from certificate OIDs
(69) eap_tls: TLS-Cert-Serial := "1009"
(69) eap_tls: TLS-Cert-Expiration := "380111125719Z"
(69) eap_tls: TLS-Cert-Subject := "/C=DE/ST=Sachsen/L=Leipzig/O=DBFZ Deutsches Biomasseforschungszentrum gGmbH/OU=IT/CN=CAPF-91d43ef6"
(69) eap_tls: TLS-Cert-Issuer := "/C=DE/ST=Sachsen/L=Leipzig/O=DBFZ Deutsches Biomasseforschungszentrum gemeinnuetzige GmbH/OU=IT/CN=DBFZ CA INTERN ROOT/emailAddress=support at dbfz.de"
(69) eap_tls: TLS-Cert-Common-Name := "CAPF-91d43ef6"
(69) eap_tls: ERROR: SSL says error 26 : unsupported certificate purpose
(69) eap_tls: >>> send TLS 1.0 Alert [length 0002], fatal unsupported_certificate
(69) eap_tls: ERROR: TLS Alert write:fatal:unsupported certificate
tls: TLS_accept: Error in error
(69) eap_tls: ERROR: Failed in __FUNCTION__ (SSL_read): error:1417C086:SSL routines:tls_process_client_certificate:certificate verify failed
(69) eap_tls: ERROR: System call (I/O) error (-1)
(69) eap_tls: ERROR: TLS receive handshake failed during operation
(69) eap_tls: ERROR: [eaptls process] = fail </DEBUG>
openssl -verify have no warning, if I do cert check manually. Fo testing, I append the certs.
# openssl verify -verbose -CAfile /etc/freeradius/3.0/certs.8021x.ciscophone/cacert.capf.pem SEP64A0E714844E-L1.pem # SEP64A0E714844E-L1.pem: OK
Regards
Robert
-----Ursprüngliche Nachricht-----
Von: Stefan Winter [mailto:stefan.winter at restena.lu]
Gesendet: Donnerstag, 21. Dezember 2017 14:52
An: FreeRadius users mailing list <freeradius-users at lists.freeradius.org>; Boris Lytochkin <lytboris at yandex-team.ru>; Gladewitz, Robert <Robert.Gladewitz at dbfz.de>
Betreff: Re: After Upgrade from freeradius 2 to 3 (Debian 8 - 9): TLS Alert write:fatal:unsupported certificate
Hi,
> It's much better to fix your "CA" cert (which is not).
> ================
> X509v3 Basic Constraints: critical
> CA:TRUE
> ================
> is missing.
Out of curiosity (I didn't think Cisco can be so stupid to make CAs which aren't actually CAs...) I searched, and my search engine of choice gave me this link:
https://bst.cloudapps.cisco.com/bugsearch/bug/CSCut82798/?referring_site=bugquickviewredir
(needs free registration to view)
So, indeed, Cisco WAS that stupid. For an extended amount of time and multiple major version releases.
FWIW, if the OP can upgrade his system to release 11.5 and re-generate the CAPF CA, then he should get a real CA.
Which then makes tinkering with source code obsolete.
(If the answer is that you need to edit the source code, then you are asking the wrong question :-) )
Greetings,
Stefan Winter
Am 20.12.2017 um 07:51 schrieb Boris Lytochkin:
> Hi.
>
> See http://www.alvestrand.no/objectid/2.5.29.19.html
>
> On 20.12.2017 1:09, Gladewitz, Robert via Freeradius-Users wrote:
>> Hello Alan,
>>
>> so, i find out that you are right. I find out, that the certificate
>> check ends with an warning, because of following openssl function in
>> v3_purp.c?
>>
>> 495 /*-
>> 496 * CA checks common to all purposes
>> 497 * return codes:
>> 498 * 0 not a CA
>> 499 * 1 is a CA
>> 500 * 2 basicConstraints absent so "maybe" a CA
>> 501 * 3 basicConstraints absent but self signed V1.
>> 502 * 4 basicConstraints absent but keyUsage present and
>> keyCertSign asserted.
>> 503 */
>> 504
>> 505 static int check_ca(const X509 *x)
>> 506 {
>> 507 /* keyUsage if present should allow cert signing */
>> 508 if (ku_reject(x, KU_KEY_CERT_SIGN))
>> 509 return 0;
>> 510 if (x->ex_flags & EXFLAG_BCONS) {
>> 511 if (x->ex_flags & EXFLAG_CA)
>> 512 return 1;
>> 513 /* If basicConstraints says not a CA then say so */
>> 514 else
>> 515 return 0;
>> 516 } else {
>> 517 /* we support V1 roots for... uh, I don't really know
>> why. */
>> 518 if ((x->ex_flags & V1_ROOT) == V1_ROOT)
>> 519 return 3;
>> 520 /*
>> 521 * If key usage present it must have certSign so
>> tolerate it
>> 522 */
>> 523 else if (x->ex_flags & EXFLAG_KUSAGE)
>> 524 return 4;
>> 525 /* Older certificates could have Netscape-specific CA
>> types */
>> 526 else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert &
>> NS_ANY_CA)
>> 527 return 5;
>> 528 /* can this still be regarded a CA certificate? I
>> doubt it */
>> 529 return 0;
>> 530 }
>> 531 }
>>
>> But it is documented as a warning, not an error!?
>>
>> It is possible, to add an workarround for mistake in conf / tls.c
>>
>> <DIFF tls.c>
>> if (!my_ok &&
>> (conf->allow_expired_crl) &&
>> (err == X509_V_ERR_CRL_HAS_EXPIRED)) {
>> my_ok = 1;
>> X509_STORE_CTX_set_error( ctx, 0 );
>> }
>>
>> + if (!my_ok &&
>> + (conf->allow_wrong_purposed) &&
>> + (err == X509_V_ERR_INVALID_PURPOSE)) {
>> + my_ok = 1;
>> + X509_STORE_CTX_set_error( ctx, 0 );
>> + }
>>
>> if (!my_ok) {
>>
>> </DIFF>
>>
>> I hope, my mail not sounds arogant :-(
>>
>> Robert
>>
>>
>> -----Ursprüngliche Nachricht-----
>> Von: Freeradius-Users
>> [mailto:freeradius-users-bounces+robert.gladewitz=dbfz.de at lists.freer
>> adius.org]
>> Im Auftrag von Alan DeKok
>> Gesendet: Dienstag, 19. Dezember 2017 18:49
>> An: FreeRadius users mailing list
>> <freeradius-users at lists.freeradius.org>
>> Betreff: Re: After Upgrade from freeradius 2 to 3 (Debian 8 - 9): TLS
>> Alert write:fatal:unsupported certificate
>>
>>
>>> On Dec 19, 2017, at 12:18 PM, Boris Lytochkin
>>> <lytboris at yandex-team.ru> wrote:
>>> Alan, you are absolutely correct about OIDs. But one thing drives me
>>> crazy. Robert sent me a full capture (attached) and it is really
>>> weird if you compare it to FreeRADIUS logs.
>>> ...
>>> I have no idea why FreeRADIUS peeks issuer's cert instead of real
>>> client's one. I guess something is broken in server's configuration...
>> EAP-TLS sends over the entire certificate chain. OpenSSL walks
>> down the certificate chain, verifying each cert in sequence.
>>
>> If it can't verify the CA or server cert, OpenSSL fails, and we
>> never get to check the client cert.
>>
>> When the client cert gets printed, the fields get printed as
>> "TLS-Client-Cert-Serial", not as "TLS-Cert-Serial"
>>
>> Alan DeKok.
>>
>>
>> -
>> List info/subscribe/unsubscribe? See
>> http://www.freeradius.org/list/users.html
>>
>> -
>> List info/subscribe/unsubscribe? See
>> http://www.freeradius.org/list/users.html
>
--
Stefan WINTER
Ingenieur de Recherche
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Tel: +352 424409 1
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