root / ui / vnc-tls.c @ bd5c51ee
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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" |
| 29 |
#include "qemu/sockets.h" |
| 30 |
|
| 31 |
#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 |
| 32 |
/* Very verbose, so only enabled for _VNC_DEBUG >= 2 */
|
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static void vnc_debug_gnutls_log(int level, const char* str) { |
| 34 |
VNC_DEBUG("%d %s", level, str);
|
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} |
| 36 |
#endif /* defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 */ |
| 37 |
|
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|
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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) |
| 43 |
{
|
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static int tlsinitialized = 0; |
| 45 |
|
| 46 |
if (tlsinitialized)
|
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return 1; |
| 48 |
|
| 49 |
if (gnutls_global_init () < 0) |
| 50 |
return 0; |
| 51 |
|
| 52 |
/* XXX ought to re-generate diffie-hellman params periodically */
|
| 53 |
if (gnutls_dh_params_init (&dh_params) < 0) |
| 54 |
return 0; |
| 55 |
if (gnutls_dh_params_generate2 (dh_params, DH_BITS) < 0) |
| 56 |
return 0; |
| 57 |
|
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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); |
| 61 |
#endif
|
| 62 |
|
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tlsinitialized = 1;
|
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|
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return 1; |
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} |
| 67 |
|
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static ssize_t vnc_tls_push(gnutls_transport_ptr_t transport,
|
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const void *data, |
| 70 |
size_t len) {
|
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struct VncState *vs = (struct VncState *)transport; |
| 72 |
int ret;
|
| 73 |
|
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retry:
|
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ret = send(vs->csock, data, len, 0);
|
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if (ret < 0) { |
| 77 |
if (errno == EINTR)
|
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goto retry;
|
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return -1; |
| 80 |
} |
| 81 |
return ret;
|
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} |
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|
| 84 |
|
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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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|
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retry:
|
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ret = qemu_recv(vs->csock, data, len, 0);
|
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if (ret < 0) { |
| 94 |
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_t vnc_tls_initialize_anon_cred(void) |
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{
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gnutls_anon_server_credentials_t 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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|
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gnutls_anon_set_server_dh_params(anon_cred, dh_params); |
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|
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return anon_cred;
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} |
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|
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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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} |
| 127 |
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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} |
| 131 |
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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} |
| 135 |
|
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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; |
| 139 |
} |
| 140 |
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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} |
| 147 |
|
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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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} |
| 156 |
|
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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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} |
| 166 |
|
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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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{
|
| 175 |
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");
|
| 182 |
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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} |
| 186 |
|
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if ((now = time(NULL)) == ((time_t)-1)) { |
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return -1; |
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} |
| 190 |
|
| 191 |
if (status != 0) { |
| 192 |
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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|
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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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|
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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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|
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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; |
| 221 |
|
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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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} |
| 226 |
|
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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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} |
| 232 |
|
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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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} |
| 238 |
|
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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); |
| 242 |
return -1; |
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} |
| 244 |
|
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if (i == 0) { |
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size_t dnameSize = 1024;
|
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vs->tls.dname = g_malloc(dnameSize); |
| 248 |
requery:
|
| 249 |
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 = g_realloc(vs->tls.dname, dnameSize); |
| 252 |
goto requery;
|
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} |
| 254 |
gnutls_x509_crt_deinit (cert); |
| 255 |
VNC_DEBUG("Cannot get client distinguished name: %s",
|
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gnutls_strerror (ret)); |
| 257 |
return -1; |
| 258 |
} |
| 259 |
|
| 260 |
if (vs->vd->tls.x509verify) {
|
| 261 |
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); |
| 265 |
continue;
|
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} |
| 267 |
|
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allow = qemu_acl_party_is_allowed(vs->vd->tls.acl, |
| 269 |
vs->tls.dname); |
| 270 |
|
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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) {
|
| 274 |
gnutls_x509_crt_deinit (cert); |
| 275 |
return -1; |
| 276 |
} |
| 277 |
} |
| 278 |
} |
| 279 |
|
| 280 |
gnutls_x509_crt_deinit (cert); |
| 281 |
} |
| 282 |
|
| 283 |
return 0; |
| 284 |
} |
| 285 |
|
| 286 |
#if defined(GNUTLS_VERSION_NUMBER) && \
|
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GNUTLS_VERSION_NUMBER >= 0x020200 /* 2.2.0 */ |
| 288 |
|
| 289 |
static int vnc_set_gnutls_priority(gnutls_session_t s, int x509) |
| 290 |
{
|
| 291 |
const char *priority = x509 ? "NORMAL" : "NORMAL:+ANON-DH"; |
| 292 |
int rc;
|
| 293 |
|
| 294 |
rc = gnutls_priority_set_direct(s, priority, NULL);
|
| 295 |
if (rc != GNUTLS_E_SUCCESS) {
|
| 296 |
return -1; |
| 297 |
} |
| 298 |
return 0; |
| 299 |
} |
| 300 |
|
| 301 |
#else
|
| 302 |
|
| 303 |
static int vnc_set_gnutls_priority(gnutls_session_t s, int x509) |
| 304 |
{
|
| 305 |
static const int cert_types[] = { GNUTLS_CRT_X509, 0 }; |
| 306 |
static const int protocols[] = { |
| 307 |
GNUTLS_TLS1_1, GNUTLS_TLS1_0, GNUTLS_SSL3, 0
|
| 308 |
}; |
| 309 |
static const int kx_anon[] = { GNUTLS_KX_ANON_DH, 0 }; |
| 310 |
static const int kx_x509[] = { |
| 311 |
GNUTLS_KX_DHE_DSS, GNUTLS_KX_RSA, |
| 312 |
GNUTLS_KX_DHE_RSA, GNUTLS_KX_SRP, 0
|
| 313 |
}; |
| 314 |
int rc;
|
| 315 |
|
| 316 |
rc = gnutls_kx_set_priority(s, x509 ? kx_x509 : kx_anon); |
| 317 |
if (rc != GNUTLS_E_SUCCESS) {
|
| 318 |
return -1; |
| 319 |
} |
| 320 |
|
| 321 |
rc = gnutls_certificate_type_set_priority(s, cert_types); |
| 322 |
if (rc != GNUTLS_E_SUCCESS) {
|
| 323 |
return -1; |
| 324 |
} |
| 325 |
|
| 326 |
rc = gnutls_protocol_set_priority(s, protocols); |
| 327 |
if (rc != GNUTLS_E_SUCCESS) {
|
| 328 |
return -1; |
| 329 |
} |
| 330 |
return 0; |
| 331 |
} |
| 332 |
|
| 333 |
#endif
|
| 334 |
|
| 335 |
int vnc_tls_client_setup(struct VncState *vs, |
| 336 |
int needX509Creds) {
|
| 337 |
VncStateTLS *tls; |
| 338 |
|
| 339 |
VNC_DEBUG("Do TLS setup\n");
|
| 340 |
#ifdef CONFIG_VNC_WS
|
| 341 |
if (vs->websocket) {
|
| 342 |
tls = &vs->ws_tls; |
| 343 |
} else
|
| 344 |
#endif /* CONFIG_VNC_WS */ |
| 345 |
{
|
| 346 |
tls = &vs->tls; |
| 347 |
} |
| 348 |
if (vnc_tls_initialize() < 0) { |
| 349 |
VNC_DEBUG("Failed to init TLS\n");
|
| 350 |
vnc_client_error(vs); |
| 351 |
return -1; |
| 352 |
} |
| 353 |
if (tls->session == NULL) { |
| 354 |
if (gnutls_init(&tls->session, GNUTLS_SERVER) < 0) { |
| 355 |
vnc_client_error(vs); |
| 356 |
return -1; |
| 357 |
} |
| 358 |
|
| 359 |
if (gnutls_set_default_priority(tls->session) < 0) { |
| 360 |
gnutls_deinit(tls->session); |
| 361 |
tls->session = NULL;
|
| 362 |
vnc_client_error(vs); |
| 363 |
return -1; |
| 364 |
} |
| 365 |
|
| 366 |
if (vnc_set_gnutls_priority(tls->session, needX509Creds) < 0) { |
| 367 |
gnutls_deinit(tls->session); |
| 368 |
tls->session = NULL;
|
| 369 |
vnc_client_error(vs); |
| 370 |
return -1; |
| 371 |
} |
| 372 |
|
| 373 |
if (needX509Creds) {
|
| 374 |
gnutls_certificate_server_credentials x509_cred = vnc_tls_initialize_x509_cred(vs->vd); |
| 375 |
if (!x509_cred) {
|
| 376 |
gnutls_deinit(tls->session); |
| 377 |
tls->session = NULL;
|
| 378 |
vnc_client_error(vs); |
| 379 |
return -1; |
| 380 |
} |
| 381 |
if (gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) { |
| 382 |
gnutls_deinit(tls->session); |
| 383 |
tls->session = NULL;
|
| 384 |
gnutls_certificate_free_credentials(x509_cred); |
| 385 |
vnc_client_error(vs); |
| 386 |
return -1; |
| 387 |
} |
| 388 |
if (vs->vd->tls.x509verify) {
|
| 389 |
VNC_DEBUG("Requesting a client certificate\n");
|
| 390 |
gnutls_certificate_server_set_request (tls->session, GNUTLS_CERT_REQUEST); |
| 391 |
} |
| 392 |
|
| 393 |
} else {
|
| 394 |
gnutls_anon_server_credentials_t anon_cred = vnc_tls_initialize_anon_cred(); |
| 395 |
if (!anon_cred) {
|
| 396 |
gnutls_deinit(tls->session); |
| 397 |
tls->session = NULL;
|
| 398 |
vnc_client_error(vs); |
| 399 |
return -1; |
| 400 |
} |
| 401 |
if (gnutls_credentials_set(tls->session, GNUTLS_CRD_ANON, anon_cred) < 0) { |
| 402 |
gnutls_deinit(tls->session); |
| 403 |
tls->session = NULL;
|
| 404 |
gnutls_anon_free_server_credentials(anon_cred); |
| 405 |
vnc_client_error(vs); |
| 406 |
return -1; |
| 407 |
} |
| 408 |
} |
| 409 |
|
| 410 |
gnutls_transport_set_ptr(tls->session, (gnutls_transport_ptr_t)vs); |
| 411 |
gnutls_transport_set_push_function(tls->session, vnc_tls_push); |
| 412 |
gnutls_transport_set_pull_function(tls->session, vnc_tls_pull); |
| 413 |
} |
| 414 |
return 0; |
| 415 |
} |
| 416 |
|
| 417 |
|
| 418 |
void vnc_tls_client_cleanup(struct VncState *vs) |
| 419 |
{
|
| 420 |
if (vs->tls.session) {
|
| 421 |
gnutls_deinit(vs->tls.session); |
| 422 |
vs->tls.session = NULL;
|
| 423 |
} |
| 424 |
vs->tls.wiremode = VNC_WIREMODE_CLEAR; |
| 425 |
g_free(vs->tls.dname); |
| 426 |
#ifdef CONFIG_VNC_WS
|
| 427 |
if (vs->ws_tls.session) {
|
| 428 |
gnutls_deinit(vs->ws_tls.session); |
| 429 |
vs->ws_tls.session = NULL;
|
| 430 |
} |
| 431 |
vs->ws_tls.wiremode = VNC_WIREMODE_CLEAR; |
| 432 |
g_free(vs->ws_tls.dname); |
| 433 |
#endif /* CONFIG_VNC_WS */ |
| 434 |
} |
| 435 |
|
| 436 |
|
| 437 |
|
| 438 |
static int vnc_set_x509_credential(VncDisplay *vd, |
| 439 |
const char *certdir, |
| 440 |
const char *filename, |
| 441 |
char **cred,
|
| 442 |
int ignoreMissing)
|
| 443 |
{
|
| 444 |
struct stat sb;
|
| 445 |
|
| 446 |
if (*cred) {
|
| 447 |
g_free(*cred); |
| 448 |
*cred = NULL;
|
| 449 |
} |
| 450 |
|
| 451 |
*cred = g_malloc(strlen(certdir) + strlen(filename) + 2);
|
| 452 |
|
| 453 |
strcpy(*cred, certdir); |
| 454 |
strcat(*cred, "/");
|
| 455 |
strcat(*cred, filename); |
| 456 |
|
| 457 |
VNC_DEBUG("Check %s\n", *cred);
|
| 458 |
if (stat(*cred, &sb) < 0) { |
| 459 |
g_free(*cred); |
| 460 |
*cred = NULL;
|
| 461 |
if (ignoreMissing && errno == ENOENT)
|
| 462 |
return 0; |
| 463 |
return -1; |
| 464 |
} |
| 465 |
|
| 466 |
return 0; |
| 467 |
} |
| 468 |
|
| 469 |
|
| 470 |
int vnc_tls_set_x509_creds_dir(VncDisplay *vd,
|
| 471 |
const char *certdir) |
| 472 |
{
|
| 473 |
if (vnc_set_x509_credential(vd, certdir, X509_CA_CERT_FILE, &vd->tls.x509cacert, 0) < 0) |
| 474 |
goto cleanup;
|
| 475 |
if (vnc_set_x509_credential(vd, certdir, X509_CA_CRL_FILE, &vd->tls.x509cacrl, 1) < 0) |
| 476 |
goto cleanup;
|
| 477 |
if (vnc_set_x509_credential(vd, certdir, X509_SERVER_CERT_FILE, &vd->tls.x509cert, 0) < 0) |
| 478 |
goto cleanup;
|
| 479 |
if (vnc_set_x509_credential(vd, certdir, X509_SERVER_KEY_FILE, &vd->tls.x509key, 0) < 0) |
| 480 |
goto cleanup;
|
| 481 |
|
| 482 |
return 0; |
| 483 |
|
| 484 |
cleanup:
|
| 485 |
g_free(vd->tls.x509cacert); |
| 486 |
g_free(vd->tls.x509cacrl); |
| 487 |
g_free(vd->tls.x509cert); |
| 488 |
g_free(vd->tls.x509key); |
| 489 |
vd->tls.x509cacert = vd->tls.x509cacrl = vd->tls.x509cert = vd->tls.x509key = NULL;
|
| 490 |
return -1; |
| 491 |
} |
| 492 |
|