xref: /openbmc/qemu/crypto/tlssession.c (revision 24ad5e19952b326796c8a3a1595c57ff180dab84)
1 /*
2  * QEMU crypto TLS session support
3  *
4  * Copyright (c) 2015 Red Hat, Inc.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  *
19  */
20 
21 #include "qemu/osdep.h"
22 #include "qemu/thread.h"
23 #include "crypto/tlssession.h"
24 #include "crypto/tlscredsanon.h"
25 #include "crypto/tlscredspsk.h"
26 #include "crypto/tlscredsx509.h"
27 #include "qapi/error.h"
28 #include "authz/base.h"
29 #include "tlscredspriv.h"
30 #include "trace.h"
31 
32 #ifdef CONFIG_GNUTLS
33 
34 
35 #include <gnutls/x509.h>
36 
37 
38 struct QCryptoTLSSession {
39     QCryptoTLSCreds *creds;
40     gnutls_session_t handle;
41     char *hostname;
42     char *authzid;
43     bool handshakeComplete;
44     QCryptoTLSSessionWriteFunc writeFunc;
45     QCryptoTLSSessionReadFunc readFunc;
46     void *opaque;
47     char *peername;
48 
49     /*
50      * Allow concurrent reads and writes, so track
51      * errors separately
52      */
53     Error *rerr;
54     Error *werr;
55 
56     /*
57      * Used to protect against broken GNUTLS thread safety
58      * https://gitlab.com/gnutls/gnutls/-/issues/1717
59      */
60     bool requireThreadSafety;
61     bool lockEnabled;
62     QemuMutex lock;
63 };
64 
65 
66 void
67 qcrypto_tls_session_free(QCryptoTLSSession *session)
68 {
69     if (!session) {
70         return;
71     }
72 
73     error_free(session->rerr);
74     error_free(session->werr);
75 
76     gnutls_deinit(session->handle);
77     g_free(session->hostname);
78     g_free(session->peername);
79     g_free(session->authzid);
80     object_unref(OBJECT(session->creds));
81     qemu_mutex_destroy(&session->lock);
82     g_free(session);
83 }
84 
85 
86 static ssize_t
87 qcrypto_tls_session_push(void *opaque, const void *buf, size_t len)
88 {
89     QCryptoTLSSession *session = opaque;
90     ssize_t ret;
91 
92     if (!session->writeFunc) {
93         errno = EIO;
94         return -1;
95     };
96 
97     if (session->lockEnabled) {
98         qemu_mutex_unlock(&session->lock);
99     }
100 
101     error_free(session->werr);
102     session->werr = NULL;
103 
104     ret = session->writeFunc(buf, len, session->opaque, &session->werr);
105 
106     if (session->lockEnabled) {
107         qemu_mutex_lock(&session->lock);
108     }
109 
110     if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
111         errno = EAGAIN;
112         return -1;
113     } else if (ret < 0) {
114         errno = EIO;
115         return -1;
116     } else {
117         return ret;
118     }
119 }
120 
121 
122 static ssize_t
123 qcrypto_tls_session_pull(void *opaque, void *buf, size_t len)
124 {
125     QCryptoTLSSession *session = opaque;
126     ssize_t ret;
127 
128     if (!session->readFunc) {
129         errno = EIO;
130         return -1;
131     };
132 
133     error_free(session->rerr);
134     session->rerr = NULL;
135 
136     if (session->lockEnabled) {
137         qemu_mutex_unlock(&session->lock);
138     }
139 
140     ret = session->readFunc(buf, len, session->opaque, &session->rerr);
141 
142     if (session->lockEnabled) {
143         qemu_mutex_lock(&session->lock);
144     }
145 
146     if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
147         errno = EAGAIN;
148         return -1;
149     } else if (ret < 0) {
150         errno = EIO;
151         return -1;
152     } else {
153         return ret;
154     }
155 }
156 
157 #define TLS_PRIORITY_ADDITIONAL_ANON "+ANON-DH"
158 #define TLS_PRIORITY_ADDITIONAL_PSK "+ECDHE-PSK:+DHE-PSK:+PSK"
159 
160 QCryptoTLSSession *
161 qcrypto_tls_session_new(QCryptoTLSCreds *creds,
162                         const char *hostname,
163                         const char *authzid,
164                         QCryptoTLSCredsEndpoint endpoint,
165                         Error **errp)
166 {
167     QCryptoTLSSession *session;
168     int ret;
169 
170     session = g_new0(QCryptoTLSSession, 1);
171     trace_qcrypto_tls_session_new(
172         session, creds, hostname ? hostname : "<none>",
173         authzid ? authzid : "<none>", endpoint);
174 
175     if (hostname) {
176         session->hostname = g_strdup(hostname);
177     }
178     if (authzid) {
179         session->authzid = g_strdup(authzid);
180     }
181     session->creds = creds;
182     object_ref(OBJECT(creds));
183 
184     qemu_mutex_init(&session->lock);
185 
186     if (creds->endpoint != endpoint) {
187         error_setg(errp, "Credentials endpoint doesn't match session");
188         goto error;
189     }
190 
191     if (endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
192         ret = gnutls_init(&session->handle, GNUTLS_SERVER);
193     } else {
194         ret = gnutls_init(&session->handle, GNUTLS_CLIENT);
195     }
196     if (ret < 0) {
197         error_setg(errp, "Cannot initialize TLS session: %s",
198                    gnutls_strerror(ret));
199         goto error;
200     }
201 
202     if (object_dynamic_cast(OBJECT(creds),
203                             TYPE_QCRYPTO_TLS_CREDS_ANON)) {
204         QCryptoTLSCredsAnon *acreds = QCRYPTO_TLS_CREDS_ANON(creds);
205         char *prio;
206 
207         if (creds->priority != NULL) {
208             prio = g_strdup_printf("%s:%s",
209                                    creds->priority,
210                                    TLS_PRIORITY_ADDITIONAL_ANON);
211         } else {
212             prio = g_strdup(CONFIG_TLS_PRIORITY ":"
213                             TLS_PRIORITY_ADDITIONAL_ANON);
214         }
215 
216         ret = gnutls_priority_set_direct(session->handle, prio, NULL);
217         if (ret < 0) {
218             error_setg(errp, "Unable to set TLS session priority %s: %s",
219                        prio, gnutls_strerror(ret));
220             g_free(prio);
221             goto error;
222         }
223         g_free(prio);
224         if (creds->endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
225             ret = gnutls_credentials_set(session->handle,
226                                          GNUTLS_CRD_ANON,
227                                          acreds->data.server);
228         } else {
229             ret = gnutls_credentials_set(session->handle,
230                                          GNUTLS_CRD_ANON,
231                                          acreds->data.client);
232         }
233         if (ret < 0) {
234             error_setg(errp, "Cannot set session credentials: %s",
235                        gnutls_strerror(ret));
236             goto error;
237         }
238     } else if (object_dynamic_cast(OBJECT(creds),
239                                    TYPE_QCRYPTO_TLS_CREDS_PSK)) {
240         QCryptoTLSCredsPSK *pcreds = QCRYPTO_TLS_CREDS_PSK(creds);
241         char *prio;
242 
243         if (creds->priority != NULL) {
244             prio = g_strdup_printf("%s:%s",
245                                    creds->priority,
246                                    TLS_PRIORITY_ADDITIONAL_PSK);
247         } else {
248             prio = g_strdup(CONFIG_TLS_PRIORITY ":"
249                             TLS_PRIORITY_ADDITIONAL_PSK);
250         }
251 
252         ret = gnutls_priority_set_direct(session->handle, prio, NULL);
253         if (ret < 0) {
254             error_setg(errp, "Unable to set TLS session priority %s: %s",
255                        prio, gnutls_strerror(ret));
256             g_free(prio);
257             goto error;
258         }
259         g_free(prio);
260         if (creds->endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
261             ret = gnutls_credentials_set(session->handle,
262                                          GNUTLS_CRD_PSK,
263                                          pcreds->data.server);
264         } else {
265             ret = gnutls_credentials_set(session->handle,
266                                          GNUTLS_CRD_PSK,
267                                          pcreds->data.client);
268         }
269         if (ret < 0) {
270             error_setg(errp, "Cannot set session credentials: %s",
271                        gnutls_strerror(ret));
272             goto error;
273         }
274     } else if (object_dynamic_cast(OBJECT(creds),
275                                    TYPE_QCRYPTO_TLS_CREDS_X509)) {
276         QCryptoTLSCredsX509 *tcreds = QCRYPTO_TLS_CREDS_X509(creds);
277         const char *prio = creds->priority;
278         if (!prio) {
279             prio = CONFIG_TLS_PRIORITY;
280         }
281 
282         ret = gnutls_priority_set_direct(session->handle, prio, NULL);
283         if (ret < 0) {
284             error_setg(errp, "Cannot set default TLS session priority %s: %s",
285                        prio, gnutls_strerror(ret));
286             goto error;
287         }
288         ret = gnutls_credentials_set(session->handle,
289                                      GNUTLS_CRD_CERTIFICATE,
290                                      tcreds->data);
291         if (ret < 0) {
292             error_setg(errp, "Cannot set session credentials: %s",
293                        gnutls_strerror(ret));
294             goto error;
295         }
296 
297         if (creds->endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
298             /* This requests, but does not enforce a client cert.
299              * The cert checking code later does enforcement */
300             gnutls_certificate_server_set_request(session->handle,
301                                                   GNUTLS_CERT_REQUEST);
302         }
303     } else {
304         error_setg(errp, "Unsupported TLS credentials type %s",
305                    object_get_typename(OBJECT(creds)));
306         goto error;
307     }
308 
309     gnutls_transport_set_ptr(session->handle, session);
310     gnutls_transport_set_push_function(session->handle,
311                                        qcrypto_tls_session_push);
312     gnutls_transport_set_pull_function(session->handle,
313                                        qcrypto_tls_session_pull);
314 
315     return session;
316 
317  error:
318     qcrypto_tls_session_free(session);
319     return NULL;
320 }
321 
322 void qcrypto_tls_session_require_thread_safety(QCryptoTLSSession *sess)
323 {
324     sess->requireThreadSafety = true;
325 }
326 
327 static int
328 qcrypto_tls_session_check_certificate(QCryptoTLSSession *session,
329                                       Error **errp)
330 {
331     int ret;
332     unsigned int status;
333     const gnutls_datum_t *certs;
334     unsigned int nCerts, i;
335     time_t now;
336     gnutls_x509_crt_t cert = NULL;
337     Error *err = NULL;
338 
339     now = time(NULL);
340     if (now == ((time_t)-1)) {
341         error_setg_errno(errp, errno, "Cannot get current time");
342         return -1;
343     }
344 
345     ret = gnutls_certificate_verify_peers2(session->handle, &status);
346     if (ret < 0) {
347         error_setg(errp, "Verify failed: %s", gnutls_strerror(ret));
348         return -1;
349     }
350 
351     if (status != 0) {
352         const char *reason = "Invalid certificate";
353 
354         if (status & GNUTLS_CERT_INVALID) {
355             reason = "The certificate is not trusted";
356         }
357 
358         if (status & GNUTLS_CERT_SIGNER_NOT_FOUND) {
359             reason = "The certificate hasn't got a known issuer";
360         }
361 
362         if (status & GNUTLS_CERT_REVOKED) {
363             reason = "The certificate has been revoked";
364         }
365 
366         if (status & GNUTLS_CERT_INSECURE_ALGORITHM) {
367             reason = "The certificate uses an insecure algorithm";
368         }
369 
370         error_setg(errp, "%s", reason);
371         return -1;
372     }
373 
374     certs = gnutls_certificate_get_peers(session->handle, &nCerts);
375     if (!certs) {
376         error_setg(errp, "No certificate peers");
377         return -1;
378     }
379 
380     for (i = 0; i < nCerts; i++) {
381         ret = gnutls_x509_crt_init(&cert);
382         if (ret < 0) {
383             error_setg(errp, "Cannot initialize certificate: %s",
384                        gnutls_strerror(ret));
385             return -1;
386         }
387 
388         ret = gnutls_x509_crt_import(cert, &certs[i], GNUTLS_X509_FMT_DER);
389         if (ret < 0) {
390             error_setg(errp, "Cannot import certificate: %s",
391                        gnutls_strerror(ret));
392             goto error;
393         }
394 
395         if (gnutls_x509_crt_get_expiration_time(cert) < now) {
396             error_setg(errp, "The certificate has expired");
397             goto error;
398         }
399 
400         if (gnutls_x509_crt_get_activation_time(cert) > now) {
401             error_setg(errp, "The certificate is not yet activated");
402             goto error;
403         }
404 
405         if (gnutls_x509_crt_get_activation_time(cert) > now) {
406             error_setg(errp, "The certificate is not yet activated");
407             goto error;
408         }
409 
410         if (i == 0) {
411             size_t dnameSize = 1024;
412             session->peername = g_malloc(dnameSize);
413         requery:
414             ret = gnutls_x509_crt_get_dn(cert, session->peername, &dnameSize);
415             if (ret < 0) {
416                 if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) {
417                     session->peername = g_realloc(session->peername,
418                                                   dnameSize);
419                     goto requery;
420                 }
421                 error_setg(errp, "Cannot get client distinguished name: %s",
422                            gnutls_strerror(ret));
423                 goto error;
424             }
425             if (session->authzid) {
426                 bool allow;
427 
428                 allow = qauthz_is_allowed_by_id(session->authzid,
429                                                 session->peername, &err);
430                 if (err) {
431                     error_propagate(errp, err);
432                     goto error;
433                 }
434                 if (!allow) {
435                     error_setg(errp, "TLS x509 authz check for %s is denied",
436                                session->peername);
437                     goto error;
438                 }
439             }
440             if (session->hostname) {
441                 if (!gnutls_x509_crt_check_hostname(cert, session->hostname)) {
442                     error_setg(errp,
443                                "Certificate does not match the hostname %s",
444                                session->hostname);
445                     goto error;
446                 }
447             } else {
448                 if (session->creds->endpoint ==
449                     QCRYPTO_TLS_CREDS_ENDPOINT_CLIENT) {
450                     error_setg(errp, "No hostname for certificate validation");
451                     goto error;
452                 }
453             }
454         }
455 
456         gnutls_x509_crt_deinit(cert);
457     }
458 
459     return 0;
460 
461  error:
462     gnutls_x509_crt_deinit(cert);
463     return -1;
464 }
465 
466 
467 int
468 qcrypto_tls_session_check_credentials(QCryptoTLSSession *session,
469                                       Error **errp)
470 {
471     if (object_dynamic_cast(OBJECT(session->creds),
472                             TYPE_QCRYPTO_TLS_CREDS_ANON)) {
473         trace_qcrypto_tls_session_check_creds(session, "nop");
474         return 0;
475     } else if (object_dynamic_cast(OBJECT(session->creds),
476                             TYPE_QCRYPTO_TLS_CREDS_PSK)) {
477         trace_qcrypto_tls_session_check_creds(session, "nop");
478         return 0;
479     } else if (object_dynamic_cast(OBJECT(session->creds),
480                             TYPE_QCRYPTO_TLS_CREDS_X509)) {
481         if (session->creds->verifyPeer) {
482             int ret = qcrypto_tls_session_check_certificate(session,
483                                                             errp);
484             trace_qcrypto_tls_session_check_creds(session,
485                                                   ret == 0 ? "pass" : "fail");
486             return ret;
487         } else {
488             trace_qcrypto_tls_session_check_creds(session, "skip");
489             return 0;
490         }
491     } else {
492         trace_qcrypto_tls_session_check_creds(session, "error");
493         error_setg(errp, "Unexpected credential type %s",
494                    object_get_typename(OBJECT(session->creds)));
495         return -1;
496     }
497 }
498 
499 
500 void
501 qcrypto_tls_session_set_callbacks(QCryptoTLSSession *session,
502                                   QCryptoTLSSessionWriteFunc writeFunc,
503                                   QCryptoTLSSessionReadFunc readFunc,
504                                   void *opaque)
505 {
506     session->writeFunc = writeFunc;
507     session->readFunc = readFunc;
508     session->opaque = opaque;
509 }
510 
511 
512 ssize_t
513 qcrypto_tls_session_write(QCryptoTLSSession *session,
514                           const char *buf,
515                           size_t len,
516                           Error **errp)
517 {
518     ssize_t ret;
519 
520     if (session->lockEnabled) {
521         qemu_mutex_lock(&session->lock);
522     }
523 
524     ret = gnutls_record_send(session->handle, buf, len);
525 
526     if (session->lockEnabled) {
527         qemu_mutex_unlock(&session->lock);
528     }
529 
530     if (ret < 0) {
531         if (ret == GNUTLS_E_AGAIN) {
532             return QCRYPTO_TLS_SESSION_ERR_BLOCK;
533         } else {
534             if (session->werr) {
535                 error_propagate(errp, session->werr);
536                 session->werr = NULL;
537             } else {
538                 error_setg(errp,
539                            "Cannot write to TLS channel: %s",
540                            gnutls_strerror(ret));
541             }
542             return -1;
543         }
544     }
545 
546     return ret;
547 }
548 
549 
550 ssize_t
551 qcrypto_tls_session_read(QCryptoTLSSession *session,
552                          char *buf,
553                          size_t len,
554                          bool gracefulTermination,
555                          Error **errp)
556 {
557     ssize_t ret;
558 
559     if (session->lockEnabled) {
560         qemu_mutex_lock(&session->lock);
561     }
562 
563     ret = gnutls_record_recv(session->handle, buf, len);
564 
565     if (session->lockEnabled) {
566         qemu_mutex_unlock(&session->lock);
567     }
568 
569     if (ret < 0) {
570         if (ret == GNUTLS_E_AGAIN) {
571             return QCRYPTO_TLS_SESSION_ERR_BLOCK;
572         } else if ((ret == GNUTLS_E_PREMATURE_TERMINATION) &&
573                    gracefulTermination){
574             return 0;
575         } else {
576             if (session->rerr) {
577                 error_propagate(errp, session->rerr);
578                 session->rerr = NULL;
579             } else {
580                 error_setg(errp,
581                            "Cannot read from TLS channel: %s",
582                            gnutls_strerror(ret));
583             }
584             return -1;
585         }
586     }
587 
588     return ret;
589 }
590 
591 
592 size_t
593 qcrypto_tls_session_check_pending(QCryptoTLSSession *session)
594 {
595     return gnutls_record_check_pending(session->handle);
596 }
597 
598 
599 int
600 qcrypto_tls_session_handshake(QCryptoTLSSession *session,
601                               Error **errp)
602 {
603     int ret;
604     ret = gnutls_handshake(session->handle);
605 
606     if (!ret) {
607 #ifdef CONFIG_GNUTLS_BUG1717_WORKAROUND
608         gnutls_cipher_algorithm_t cipher =
609             gnutls_cipher_get(session->handle);
610 
611         /*
612          * Any use of rekeying in TLS 1.3 is unsafe for
613          * a gnutls with bug 1717, however, we know that
614          * QEMU won't initiate manual rekeying. Thus we
615          * only have to protect against automatic rekeying
616          * which doesn't trigger with CHACHA20
617          */
618         if (session->requireThreadSafety &&
619             gnutls_protocol_get_version(session->handle) ==
620             GNUTLS_TLS1_3 &&
621             cipher != GNUTLS_CIPHER_CHACHA20_POLY1305) {
622             session->lockEnabled = true;
623         }
624 #endif
625 
626         session->handshakeComplete = true;
627         return QCRYPTO_TLS_HANDSHAKE_COMPLETE;
628     }
629 
630     if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
631         int direction = gnutls_record_get_direction(session->handle);
632         return direction ? QCRYPTO_TLS_HANDSHAKE_SENDING :
633             QCRYPTO_TLS_HANDSHAKE_RECVING;
634     }
635 
636     if (session->rerr || session->werr) {
637         error_setg(errp, "TLS handshake failed: %s: %s",
638                    gnutls_strerror(ret),
639                    error_get_pretty(session->rerr ?
640                                     session->rerr : session->werr));
641     } else {
642         error_setg(errp, "TLS handshake failed: %s",
643                    gnutls_strerror(ret));
644     }
645 
646     error_free(session->rerr);
647     error_free(session->werr);
648     session->rerr = session->werr = NULL;
649 
650     return -1;
651 }
652 
653 
654 int
655 qcrypto_tls_session_bye(QCryptoTLSSession *session, Error **errp)
656 {
657     int ret;
658 
659     if (!session->handshakeComplete) {
660         return 0;
661     }
662 
663     if (session->lockEnabled) {
664         qemu_mutex_lock(&session->lock);
665     }
666     ret = gnutls_bye(session->handle, GNUTLS_SHUT_WR);
667 
668     if (session->lockEnabled) {
669         qemu_mutex_unlock(&session->lock);
670     }
671 
672     if (!ret) {
673         return QCRYPTO_TLS_BYE_COMPLETE;
674     }
675 
676     if (ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN) {
677         int direction = gnutls_record_get_direction(session->handle);
678         return direction ? QCRYPTO_TLS_BYE_SENDING : QCRYPTO_TLS_BYE_RECVING;
679     }
680 
681     if (session->rerr || session->werr) {
682         error_setg(errp, "TLS termination failed: %s: %s", gnutls_strerror(ret),
683                    error_get_pretty(session->rerr ?
684                                     session->rerr : session->werr));
685     } else {
686         error_setg(errp, "TLS termination failed: %s", gnutls_strerror(ret));
687     }
688 
689     error_free(session->rerr);
690     error_free(session->werr);
691     session->rerr = session->werr = NULL;
692 
693     return -1;
694 }
695 
696 int
697 qcrypto_tls_session_get_key_size(QCryptoTLSSession *session,
698                                  Error **errp)
699 {
700     gnutls_cipher_algorithm_t cipher;
701     int ssf;
702 
703     cipher = gnutls_cipher_get(session->handle);
704     ssf = gnutls_cipher_get_key_size(cipher);
705     if (!ssf) {
706         error_setg(errp, "Cannot get TLS cipher key size");
707         return -1;
708     }
709     return ssf;
710 }
711 
712 
713 char *
714 qcrypto_tls_session_get_peer_name(QCryptoTLSSession *session)
715 {
716     if (session->peername) {
717         return g_strdup(session->peername);
718     }
719     return NULL;
720 }
721 
722 
723 #else /* ! CONFIG_GNUTLS */
724 
725 
726 QCryptoTLSSession *
727 qcrypto_tls_session_new(QCryptoTLSCreds *creds G_GNUC_UNUSED,
728                         const char *hostname G_GNUC_UNUSED,
729                         const char *authzid G_GNUC_UNUSED,
730                         QCryptoTLSCredsEndpoint endpoint G_GNUC_UNUSED,
731                         Error **errp)
732 {
733     error_setg(errp, "TLS requires GNUTLS support");
734     return NULL;
735 }
736 
737 void qcrypto_tls_session_require_thread_safety(QCryptoTLSSession *sess)
738 {
739 }
740 
741 void
742 qcrypto_tls_session_free(QCryptoTLSSession *sess G_GNUC_UNUSED)
743 {
744 }
745 
746 
747 int
748 qcrypto_tls_session_check_credentials(QCryptoTLSSession *sess G_GNUC_UNUSED,
749                                       Error **errp)
750 {
751     error_setg(errp, "TLS requires GNUTLS support");
752     return -1;
753 }
754 
755 
756 void
757 qcrypto_tls_session_set_callbacks(
758     QCryptoTLSSession *sess G_GNUC_UNUSED,
759     QCryptoTLSSessionWriteFunc writeFunc G_GNUC_UNUSED,
760     QCryptoTLSSessionReadFunc readFunc G_GNUC_UNUSED,
761     void *opaque G_GNUC_UNUSED)
762 {
763 }
764 
765 
766 ssize_t
767 qcrypto_tls_session_write(QCryptoTLSSession *sess,
768                           const char *buf,
769                           size_t len,
770                           Error **errp)
771 {
772     error_setg(errp, "TLS requires GNUTLS support");
773     return -1;
774 }
775 
776 
777 ssize_t
778 qcrypto_tls_session_read(QCryptoTLSSession *sess,
779                          char *buf,
780                          size_t len,
781                          bool gracefulTermination,
782                          Error **errp)
783 {
784     error_setg(errp, "TLS requires GNUTLS support");
785     return -1;
786 }
787 
788 
789 size_t
790 qcrypto_tls_session_check_pending(QCryptoTLSSession *session)
791 {
792     return 0;
793 }
794 
795 
796 int
797 qcrypto_tls_session_handshake(QCryptoTLSSession *sess,
798                               Error **errp)
799 {
800     error_setg(errp, "TLS requires GNUTLS support");
801     return -1;
802 }
803 
804 
805 int
806 qcrypto_tls_session_bye(QCryptoTLSSession *session, Error **errp)
807 {
808     return QCRYPTO_TLS_BYE_COMPLETE;
809 }
810 
811 
812 int
813 qcrypto_tls_session_get_key_size(QCryptoTLSSession *sess,
814                                  Error **errp)
815 {
816     error_setg(errp, "TLS requires GNUTLS support");
817     return -1;
818 }
819 
820 
821 char *
822 qcrypto_tls_session_get_peer_name(QCryptoTLSSession *sess)
823 {
824     return NULL;
825 }
826 
827 #endif
828