Hi Daniel Ah, that’s the bit I misunderstood. I thought that require_certificate would trigger mutual auth / mTLS rather than enforcing its presence.

No sign of a setting on the Yealink to send it’s certificate. Will go unpack a Cisco and see what that offers. Thanks Mark, > On 3 Jul 2020, at 09:09, Daniel-Constantin Mierla &lt;miconda(a)gmail.com <mailto:miconda@gmail.com>> wrote: > > Hello, > > the client has to be configured to present a certificate, and it doesn't do it based on kamailio log message: > > INFO: tls [tls_server.c:445]: tls_accept(): tls_accept: client did not present a certificate > > Check the phone config to see if you can set such option. Kamailio can just see if a certificate is sent and if not reject the connection, if you have require_certificate = yes in the server profile of tls.cfg > > You can eventually test with 'openssl s_client ...' to see details of client side certs in kamailio -- iirc, it has the options to specify client side certificate with -cert ... -key ... > Cheers, > Daniel > On 03.07.20 09:52, Mark Boyce wrote: >> Hi Daniel >> >> I’m testing with a Yealink T57W. It comes with a factory install certificate which will probably fail validation as the common name is the MAC. >> >> I'm not trying validate the client device’s certificate just get it to offer what it has so I can check the details. >> >> Thanks >> Mark >> >>> On 3 Jul 2020, at 08:38, Daniel-Constantin Mierla &lt;miconda(a)gmail.com <mailto:miconda@gmail.com>> wrote: >>> >>> Hello, >>> >>> what is the SIP client app you used? Is it configured to use its own tls certificate when connecting to the SIP server? >>> >>> Cheers, >>> Daniel >>> On 02.07.20 18:51, Mark Boyce wrote: >>>> Hi all >>>> >>>> Been trying to grab the TLS cert details from incoming connections, but failing :-( >>>> >>>> So with lines just before AUTH is called like this; >>>> >>>> if (proto == TLS) { >>>> xlog("L_INFO", "TLSDUMP $ci peer_subject : $tls_peer_subject\n"); >>>> >>>> Gets met with a log line line this; >>>> >>>> INFO: tls [tls_server.c:431]: tls_accept(): tls_accept: new connection from 1.2.3.4:11797 using TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256 >>>> INFO: tls [tls_server.c:434]: tls_accept(): tls_accept: local socket: 5.6.7.8:5061 >>>> INFO: tls [tls_server.c:445]: tls_accept(): tls_accept: client did not present a certificate >>>> ... >>>> INFO: tls [tls_select.c:168]: get_cert(): Unable to retrieve peer TLS certificate from SSL structure >>>> >>>> This is with verify_certificate and require_certificate set to no in tls.cfg >>>> >>>> If I try and set the following in tls.cfg >>>> >>>> [server:default] >>>> method = TLSv1.2+ >>>> verify_certificate = no >>>> require_certificate = yes >>>> >>>> I see in the logs; >>>> >>>> INFO: tls [tls_domain.c:303]: ksr_tls_fill_missing(): TLSs<default>: tls_method=22 >>>> INFO: tls [tls_domain.c:315]: ksr_tls_fill_missing(): TLSs<default>: certificate='/etc/kamailio/tls-certs/cert.pem' >>>> INFO: tls [tls_domain.c:322]: ksr_tls_fill_missing(): TLSs<default>: ca_list='(null)' >>>> INFO: tls [tls_domain.c:329]: ksr_tls_fill_missing(): TLSs<default>: crl='(null)' >>>> INFO: tls [tls_domain.c:333]: ksr_tls_fill_missing(): TLSs<default>: require_certificate=1 >>>> INFO: tls [tls_domain.c:340]: ksr_tls_fill_missing(): TLSs<default>: cipher_list='(null)' >>>> INFO: tls [tls_domain.c:347]: ksr_tls_fill_missing(): TLSs<default>: private_key='/etc/kamailio/tls-certs/privkey.pem' >>>> INFO: tls [tls_domain.c:351]: ksr_tls_fill_missing(): TLSs<default>: verify_certificate=0 >>>> INFO: tls [tls_domain.c:354]: ksr_tls_fill_missing(): TLSs<default>: verify_depth=9 >>>> NOTICE: tls [tls_domain.c:1095]: ksr_tls_fix_domain(): registered server_name callback handler for socket [:0], server_name='<default>' ... >>>> INFO: tls [tls_domain.c:692]: set_verification(): TLSs<default>: Client MUST present valid certificate >>>> INFO: tls [tls_domain.c:303]: ksr_tls_fill_missing(): TLSc<default>: tls_method=20 >>>> INFO: tls [tls_domain.c:315]: ksr_tls_fill_missing(): TLSc<default>: certificate='(null)' >>>> INFO: tls [tls_domain.c:322]: ksr_tls_fill_missing(): TLSc<default>: ca_list='(null)' >>>> INFO: tls [tls_domain.c:329]: ksr_tls_fill_missing(): TLSc<default>: crl='(null)' >>>> INFO: tls [tls_domain.c:333]: ksr_tls_fill_missing(): TLSc<default>: require_certificate=1 >>>> INFO: tls [tls_domain.c:340]: ksr_tls_fill_missing(): TLSc<default>: cipher_list='(null)' >>>> INFO: tls [tls_domain.c:347]: ksr_tls_fill_missing(): TLSc<default>: private_key='(null)' >>>> INFO: tls [tls_domain.c:351]: ksr_tls_fill_missing(): TLSc<default>: verify_certificate=1 >>>> INFO: tls [tls_domain.c:354]: ksr_tls_fill_missing(): TLSc<default>: verify_depth=9 >>>> INFO: tls [tls_domain.c:692]: set_verification(): TLSc<default>: Server MUST present valid certificate >>>> ... >>>> ERROR: tls [tls_util.h:42]: tls_err_ret(): TLS accept:error:1417C086:SSL routines:tls_process_client_certificate:certificate verify failed >>>> >>>> Which looks like verification is being enabled when I add require? >>>> >>>> >>>> >>>> Would someone be kind enough to point out what I am missing please? (Assuming it’s not a bug :-) >>>> >>>>