[Openvpn-users] Problem with Athena signed rsa pkcs

[Carsten M. <Car...@at...>]

Hi,

We use Athena IDProtect tokens on the client side for pkcs#11 authentication. While the client does not display any errors during the handshake via pkcs, we receive a rejection on the server side:

2025-11-27T08:31:26.281152+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 Sent fatal SSL alert: decrypt error
2025-11-27T08:31:26.281207+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 OpenSSL: error:02000068:rsa routines::bad signature::../crypto/rsa/rsa_pss.c:143:ossl_rsa_verify_PKCS1_PSS_mgf1
2025-11-27T08:31:26.281262+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 OpenSSL: error:1C880004:Provider routines::RSA lib::../providers/implementations/signature/rsa_sig.c:1084:rsa_verify_directly
2025-11-27T08:31:26.281311+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 OpenSSL: error:0A00007B:SSL routines::bad signature::../ssl/statem/statem_lib.c:582:tls_process_cert_verify
2025-11-27T08:31:26.281353+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 TLS_ERROR: BIO read tls_read_plaintext error
2025-11-27T08:31:26.281402+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 TLS Error: TLS object -> incoming plaintext read error
2025-11-27T08:31:26.281719+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 TLS Error: TLS handshake failed
2025-11-27T08:31:26.281766+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 PID packet_id_free
2025-11-27T08:31:26.281806+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 PKCS#11: __pkcs11h_openssl_ex_data_free entered - parent=0x575b0f8c3cc0, ptr=(nil), ad=0x575b0f8c3d50, idx=1, argl=0, argp=0x72efb3a80ac3
2025-11-27T08:31:26.281839+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 PID packet_id_free
2025-11-27T08:31:26.281879+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 PID packet_id_free
2025-11-27T08:31:26.281922+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 TLS: tls_session_init: entry
2025-11-27T08:31:26.281956+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 PID packet_id_init seq_backtrack=64 time_backtrack=15
2025-11-27T08:31:26.281995+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 PID packet_id_init seq_backtrack=64 time_backtrack=15
2025-11-27T08:31:26.282023+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 TLS: tls_session_init: new session object, sid=a9758fd7 30b00b25
2025-11-27T08:31:26.282068+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 TLS: tls_multi_process: i=2 state=S_UNDEF, mysid=00000000 00000000, stored-sid=00000000 00000000, stored-ip=[AF_UNSPEC]
2025-11-27T08:31:26.282113+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 Fatal TLS error (check_tls_errors_co), restarting
2025-11-27T08:31:26.282153+00:00 sgw02 ovpn-server[87519]: 192.168.51.159:54312 SIGUSR1[soft,tls-error] received, client-instance restarting
2025-11-27T08:31:26.282196+00:00 sgw02 ovpn-server[87519]: MULTI: multi_close_instance called

ovpn is v2.6 and ossl has v3.5.4. We have already tried on both sides to enforce
tls-cert-profile legacy
and tls 1.2.
Forcing ossl to legacy also did not help.

I suspect that the stick simply does not support pss, but we are also unable to get the server to accept the old procedure. The signature algorithm is sha256RSA.
Unfortunately, over 1000 tokens are already in the field and a worldwide replacement is difficult.

Has anyone had any experience with this or have any ideas about what we should check or try?

Kind regards,

Charly