root / ui / vnc-tls.c @ d4970b07
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/*
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* QEMU VNC display driver: TLS helpers
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*
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* Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
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* Copyright (C) 2006 Fabrice Bellard
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* Copyright (C) 2009 Red Hat, Inc
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu-x509.h" |
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#include "vnc.h" |
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#include "qemu_socket.h" |
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|
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#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 |
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/* Very verbose, so only enabled for _VNC_DEBUG >= 2 */
|
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static void vnc_debug_gnutls_log(int level, const char* str) { |
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VNC_DEBUG("%d %s", level, str);
|
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} |
| 36 |
#endif /* defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 */ |
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#define DH_BITS 1024 |
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static gnutls_dh_params_t dh_params;
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|
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static int vnc_tls_initialize(void) |
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{
|
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static int tlsinitialized = 0; |
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|
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if (tlsinitialized)
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return 1; |
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|
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if (gnutls_global_init () < 0) |
| 50 |
return 0; |
| 51 |
|
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/* XXX ought to re-generate diffie-hellmen params periodically */
|
| 53 |
if (gnutls_dh_params_init (&dh_params) < 0) |
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return 0; |
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if (gnutls_dh_params_generate2 (dh_params, DH_BITS) < 0) |
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return 0; |
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|
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#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 |
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gnutls_global_set_log_level(10);
|
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gnutls_global_set_log_function(vnc_debug_gnutls_log); |
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#endif
|
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|
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tlsinitialized = 1;
|
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|
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return 1; |
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} |
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|
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static ssize_t vnc_tls_push(gnutls_transport_ptr_t transport,
|
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const void *data, |
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size_t len) {
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struct VncState *vs = (struct VncState *)transport; |
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int ret;
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retry:
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ret = send(vs->csock, data, len, 0);
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if (ret < 0) { |
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if (errno == EINTR)
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goto retry;
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return -1; |
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} |
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return ret;
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} |
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|
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|
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static ssize_t vnc_tls_pull(gnutls_transport_ptr_t transport,
|
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void *data,
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size_t len) {
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struct VncState *vs = (struct VncState *)transport; |
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int ret;
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retry:
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ret = recv(vs->csock, data, len, 0);
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if (ret < 0) { |
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if (errno == EINTR)
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goto retry;
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return -1; |
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} |
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return ret;
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} |
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|
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|
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static gnutls_anon_server_credentials vnc_tls_initialize_anon_cred(void) |
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{
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gnutls_anon_server_credentials anon_cred; |
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int ret;
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|
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if ((ret = gnutls_anon_allocate_server_credentials(&anon_cred)) < 0) { |
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VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
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return NULL; |
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} |
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gnutls_anon_set_server_dh_params(anon_cred, dh_params); |
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return anon_cred;
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} |
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static gnutls_certificate_credentials_t vnc_tls_initialize_x509_cred(VncDisplay *vd)
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{
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gnutls_certificate_credentials_t x509_cred; |
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int ret;
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|
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if (!vd->tls.x509cacert) {
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VNC_DEBUG("No CA x509 certificate specified\n");
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return NULL; |
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} |
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if (!vd->tls.x509cert) {
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VNC_DEBUG("No server x509 certificate specified\n");
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return NULL; |
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} |
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if (!vd->tls.x509key) {
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VNC_DEBUG("No server private key specified\n");
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return NULL; |
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} |
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|
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if ((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0) { |
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VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
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return NULL; |
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} |
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if ((ret = gnutls_certificate_set_x509_trust_file(x509_cred,
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vd->tls.x509cacert, |
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GNUTLS_X509_FMT_PEM)) < 0) {
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VNC_DEBUG("Cannot load CA certificate %s\n", gnutls_strerror(ret));
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gnutls_certificate_free_credentials(x509_cred); |
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return NULL; |
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} |
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|
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if ((ret = gnutls_certificate_set_x509_key_file (x509_cred,
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vd->tls.x509cert, |
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vd->tls.x509key, |
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GNUTLS_X509_FMT_PEM)) < 0) {
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VNC_DEBUG("Cannot load certificate & key %s\n", gnutls_strerror(ret));
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gnutls_certificate_free_credentials(x509_cred); |
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return NULL; |
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} |
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|
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if (vd->tls.x509cacrl) {
|
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if ((ret = gnutls_certificate_set_x509_crl_file(x509_cred,
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vd->tls.x509cacrl, |
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GNUTLS_X509_FMT_PEM)) < 0) {
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VNC_DEBUG("Cannot load CRL %s\n", gnutls_strerror(ret));
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gnutls_certificate_free_credentials(x509_cred); |
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return NULL; |
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} |
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} |
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|
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gnutls_certificate_set_dh_params (x509_cred, dh_params); |
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|
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return x509_cred;
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} |
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|
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|
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int vnc_tls_validate_certificate(struct VncState *vs) |
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{
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int ret;
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unsigned int status; |
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const gnutls_datum_t *certs;
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unsigned int nCerts, i; |
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time_t now; |
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|
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VNC_DEBUG("Validating client certificate\n");
|
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if ((ret = gnutls_certificate_verify_peers2 (vs->tls.session, &status)) < 0) { |
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VNC_DEBUG("Verify failed %s\n", gnutls_strerror(ret));
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return -1; |
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} |
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|
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if ((now = time(NULL)) == ((time_t)-1)) { |
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return -1; |
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} |
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|
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if (status != 0) { |
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if (status & GNUTLS_CERT_INVALID)
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VNC_DEBUG("The certificate is not trusted.\n");
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|
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if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
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VNC_DEBUG("The certificate hasn't got a known issuer.\n");
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if (status & GNUTLS_CERT_REVOKED)
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VNC_DEBUG("The certificate has been revoked.\n");
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|
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if (status & GNUTLS_CERT_INSECURE_ALGORITHM)
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VNC_DEBUG("The certificate uses an insecure algorithm\n");
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return -1; |
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} else {
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VNC_DEBUG("Certificate is valid!\n");
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} |
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/* Only support x509 for now */
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if (gnutls_certificate_type_get(vs->tls.session) != GNUTLS_CRT_X509)
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return -1; |
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|
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if (!(certs = gnutls_certificate_get_peers(vs->tls.session, &nCerts)))
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return -1; |
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|
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for (i = 0 ; i < nCerts ; i++) { |
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gnutls_x509_crt_t cert; |
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VNC_DEBUG ("Checking certificate chain %d\n", i);
|
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if (gnutls_x509_crt_init (&cert) < 0) |
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return -1; |
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|
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if (gnutls_x509_crt_import(cert, &certs[i], GNUTLS_X509_FMT_DER) < 0) { |
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gnutls_x509_crt_deinit (cert); |
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return -1; |
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} |
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|
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if (gnutls_x509_crt_get_expiration_time (cert) < now) {
|
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VNC_DEBUG("The certificate has expired\n");
|
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gnutls_x509_crt_deinit (cert); |
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return -1; |
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} |
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|
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if (gnutls_x509_crt_get_activation_time (cert) > now) {
|
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VNC_DEBUG("The certificate is not yet activated\n");
|
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gnutls_x509_crt_deinit (cert); |
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return -1; |
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} |
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|
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if (gnutls_x509_crt_get_activation_time (cert) > now) {
|
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VNC_DEBUG("The certificate is not yet activated\n");
|
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gnutls_x509_crt_deinit (cert); |
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return -1; |
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} |
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|
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if (i == 0) { |
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size_t dnameSize = 1024;
|
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vs->tls.dname = qemu_malloc(dnameSize); |
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requery:
|
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if ((ret = gnutls_x509_crt_get_dn (cert, vs->tls.dname, &dnameSize)) != 0) { |
| 250 |
if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) {
|
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vs->tls.dname = qemu_realloc(vs->tls.dname, dnameSize); |
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goto requery;
|
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} |
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gnutls_x509_crt_deinit (cert); |
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VNC_DEBUG("Cannot get client distinguished name: %s",
|
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gnutls_strerror (ret)); |
| 257 |
return -1; |
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} |
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|
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if (vs->vd->tls.x509verify) {
|
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int allow;
|
| 262 |
if (!vs->vd->tls.acl) {
|
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VNC_DEBUG("no ACL activated, allowing access");
|
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gnutls_x509_crt_deinit (cert); |
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continue;
|
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} |
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|
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allow = qemu_acl_party_is_allowed(vs->vd->tls.acl, |
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vs->tls.dname); |
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|
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VNC_DEBUG("TLS x509 ACL check for %s is %s\n",
|
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vs->tls.dname, allow ? "allowed" : "denied"); |
| 273 |
if (!allow) {
|
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gnutls_x509_crt_deinit (cert); |
| 275 |
return -1; |
| 276 |
} |
| 277 |
} |
| 278 |
} |
| 279 |
|
| 280 |
gnutls_x509_crt_deinit (cert); |
| 281 |
} |
| 282 |
|
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return 0; |
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} |
| 285 |
|
| 286 |
|
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int vnc_tls_client_setup(struct VncState *vs, |
| 288 |
int needX509Creds) {
|
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static const int cert_type_priority[] = { GNUTLS_CRT_X509, 0 }; |
| 290 |
static const int protocol_priority[]= { GNUTLS_TLS1_1, GNUTLS_TLS1_0, GNUTLS_SSL3, 0 }; |
| 291 |
static const int kx_anon[] = {GNUTLS_KX_ANON_DH, 0}; |
| 292 |
static const int kx_x509[] = {GNUTLS_KX_DHE_DSS, GNUTLS_KX_RSA, GNUTLS_KX_DHE_RSA, GNUTLS_KX_SRP, 0}; |
| 293 |
|
| 294 |
VNC_DEBUG("Do TLS setup\n");
|
| 295 |
if (vnc_tls_initialize() < 0) { |
| 296 |
VNC_DEBUG("Failed to init TLS\n");
|
| 297 |
vnc_client_error(vs); |
| 298 |
return -1; |
| 299 |
} |
| 300 |
if (vs->tls.session == NULL) { |
| 301 |
if (gnutls_init(&vs->tls.session, GNUTLS_SERVER) < 0) { |
| 302 |
vnc_client_error(vs); |
| 303 |
return -1; |
| 304 |
} |
| 305 |
|
| 306 |
if (gnutls_set_default_priority(vs->tls.session) < 0) { |
| 307 |
gnutls_deinit(vs->tls.session); |
| 308 |
vs->tls.session = NULL;
|
| 309 |
vnc_client_error(vs); |
| 310 |
return -1; |
| 311 |
} |
| 312 |
|
| 313 |
if (gnutls_kx_set_priority(vs->tls.session, needX509Creds ? kx_x509 : kx_anon) < 0) { |
| 314 |
gnutls_deinit(vs->tls.session); |
| 315 |
vs->tls.session = NULL;
|
| 316 |
vnc_client_error(vs); |
| 317 |
return -1; |
| 318 |
} |
| 319 |
|
| 320 |
if (gnutls_certificate_type_set_priority(vs->tls.session, cert_type_priority) < 0) { |
| 321 |
gnutls_deinit(vs->tls.session); |
| 322 |
vs->tls.session = NULL;
|
| 323 |
vnc_client_error(vs); |
| 324 |
return -1; |
| 325 |
} |
| 326 |
|
| 327 |
if (gnutls_protocol_set_priority(vs->tls.session, protocol_priority) < 0) { |
| 328 |
gnutls_deinit(vs->tls.session); |
| 329 |
vs->tls.session = NULL;
|
| 330 |
vnc_client_error(vs); |
| 331 |
return -1; |
| 332 |
} |
| 333 |
|
| 334 |
if (needX509Creds) {
|
| 335 |
gnutls_certificate_server_credentials x509_cred = vnc_tls_initialize_x509_cred(vs->vd); |
| 336 |
if (!x509_cred) {
|
| 337 |
gnutls_deinit(vs->tls.session); |
| 338 |
vs->tls.session = NULL;
|
| 339 |
vnc_client_error(vs); |
| 340 |
return -1; |
| 341 |
} |
| 342 |
if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) { |
| 343 |
gnutls_deinit(vs->tls.session); |
| 344 |
vs->tls.session = NULL;
|
| 345 |
gnutls_certificate_free_credentials(x509_cred); |
| 346 |
vnc_client_error(vs); |
| 347 |
return -1; |
| 348 |
} |
| 349 |
if (vs->vd->tls.x509verify) {
|
| 350 |
VNC_DEBUG("Requesting a client certificate\n");
|
| 351 |
gnutls_certificate_server_set_request (vs->tls.session, GNUTLS_CERT_REQUEST); |
| 352 |
} |
| 353 |
|
| 354 |
} else {
|
| 355 |
gnutls_anon_server_credentials anon_cred = vnc_tls_initialize_anon_cred(); |
| 356 |
if (!anon_cred) {
|
| 357 |
gnutls_deinit(vs->tls.session); |
| 358 |
vs->tls.session = NULL;
|
| 359 |
vnc_client_error(vs); |
| 360 |
return -1; |
| 361 |
} |
| 362 |
if (gnutls_credentials_set(vs->tls.session, GNUTLS_CRD_ANON, anon_cred) < 0) { |
| 363 |
gnutls_deinit(vs->tls.session); |
| 364 |
vs->tls.session = NULL;
|
| 365 |
gnutls_anon_free_server_credentials(anon_cred); |
| 366 |
vnc_client_error(vs); |
| 367 |
return -1; |
| 368 |
} |
| 369 |
} |
| 370 |
|
| 371 |
gnutls_transport_set_ptr(vs->tls.session, (gnutls_transport_ptr_t)vs); |
| 372 |
gnutls_transport_set_push_function(vs->tls.session, vnc_tls_push); |
| 373 |
gnutls_transport_set_pull_function(vs->tls.session, vnc_tls_pull); |
| 374 |
} |
| 375 |
return 0; |
| 376 |
} |
| 377 |
|
| 378 |
|
| 379 |
void vnc_tls_client_cleanup(struct VncState *vs) |
| 380 |
{
|
| 381 |
if (vs->tls.session) {
|
| 382 |
gnutls_deinit(vs->tls.session); |
| 383 |
vs->tls.session = NULL;
|
| 384 |
} |
| 385 |
vs->tls.wiremode = VNC_WIREMODE_CLEAR; |
| 386 |
free(vs->tls.dname); |
| 387 |
} |
| 388 |
|
| 389 |
|
| 390 |
|
| 391 |
static int vnc_set_x509_credential(VncDisplay *vd, |
| 392 |
const char *certdir, |
| 393 |
const char *filename, |
| 394 |
char **cred,
|
| 395 |
int ignoreMissing)
|
| 396 |
{
|
| 397 |
struct stat sb;
|
| 398 |
|
| 399 |
if (*cred) {
|
| 400 |
qemu_free(*cred); |
| 401 |
*cred = NULL;
|
| 402 |
} |
| 403 |
|
| 404 |
*cred = qemu_malloc(strlen(certdir) + strlen(filename) + 2);
|
| 405 |
|
| 406 |
strcpy(*cred, certdir); |
| 407 |
strcat(*cred, "/");
|
| 408 |
strcat(*cred, filename); |
| 409 |
|
| 410 |
VNC_DEBUG("Check %s\n", *cred);
|
| 411 |
if (stat(*cred, &sb) < 0) { |
| 412 |
qemu_free(*cred); |
| 413 |
*cred = NULL;
|
| 414 |
if (ignoreMissing && errno == ENOENT)
|
| 415 |
return 0; |
| 416 |
return -1; |
| 417 |
} |
| 418 |
|
| 419 |
return 0; |
| 420 |
} |
| 421 |
|
| 422 |
|
| 423 |
int vnc_tls_set_x509_creds_dir(VncDisplay *vd,
|
| 424 |
const char *certdir) |
| 425 |
{
|
| 426 |
if (vnc_set_x509_credential(vd, certdir, X509_CA_CERT_FILE, &vd->tls.x509cacert, 0) < 0) |
| 427 |
goto cleanup;
|
| 428 |
if (vnc_set_x509_credential(vd, certdir, X509_CA_CRL_FILE, &vd->tls.x509cacrl, 1) < 0) |
| 429 |
goto cleanup;
|
| 430 |
if (vnc_set_x509_credential(vd, certdir, X509_SERVER_CERT_FILE, &vd->tls.x509cert, 0) < 0) |
| 431 |
goto cleanup;
|
| 432 |
if (vnc_set_x509_credential(vd, certdir, X509_SERVER_KEY_FILE, &vd->tls.x509key, 0) < 0) |
| 433 |
goto cleanup;
|
| 434 |
|
| 435 |
return 0; |
| 436 |
|
| 437 |
cleanup:
|
| 438 |
qemu_free(vd->tls.x509cacert); |
| 439 |
qemu_free(vd->tls.x509cacrl); |
| 440 |
qemu_free(vd->tls.x509cert); |
| 441 |
qemu_free(vd->tls.x509key); |
| 442 |
vd->tls.x509cacert = vd->tls.x509cacrl = vd->tls.x509cert = vd->tls.x509key = NULL;
|
| 443 |
return -1; |
| 444 |
} |
| 445 |
|