--- /dev/null
+/*
+ * QEMU VNC display driver: TLS helpers
+ *
+ * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
+ * Copyright (C) 2006 Fabrice Bellard
+ * Copyright (C) 2009 Red Hat, Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu-x509.h"
+#include "vnc.h"
+#include "qemu/sockets.h"
+
+#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2
+/* Very verbose, so only enabled for _VNC_DEBUG >= 2 */
+static void vnc_debug_gnutls_log(int level, const char* str) {
+ VNC_DEBUG("%d %s", level, str);
+}
+#endif /* defined(_VNC_DEBUG) && _VNC_DEBUG >= 2 */
+
+
+#define DH_BITS 1024
+static gnutls_dh_params_t dh_params;
+
+static int vnc_tls_initialize(void)
+{
+ static int tlsinitialized = 0;
+
+ if (tlsinitialized)
+ return 1;
+
+ if (gnutls_global_init () < 0)
+ return 0;
+
+ /* XXX ought to re-generate diffie-hellman params periodically */
+ if (gnutls_dh_params_init (&dh_params) < 0)
+ return 0;
+ if (gnutls_dh_params_generate2 (dh_params, DH_BITS) < 0)
+ return 0;
+
+#if defined(_VNC_DEBUG) && _VNC_DEBUG >= 2
+ gnutls_global_set_log_level(10);
+ gnutls_global_set_log_function(vnc_debug_gnutls_log);
+#endif
+
+ tlsinitialized = 1;
+
+ return 1;
+}
+
+static ssize_t vnc_tls_push(gnutls_transport_ptr_t transport,
+ const void *data,
+ size_t len) {
+ VncState *vs = (VncState *)transport;
+ int ret;
+
+ retry:
+ ret = send(vs->csock, data, len, 0);
+ if (ret < 0) {
+ if (errno == EINTR)
+ goto retry;
+ return -1;
+ }
+ return ret;
+}
+
+
+static ssize_t vnc_tls_pull(gnutls_transport_ptr_t transport,
+ void *data,
+ size_t len) {
+ VncState *vs = (VncState *)transport;
+ int ret;
+
+ retry:
+ ret = qemu_recv(vs->csock, data, len, 0);
+ if (ret < 0) {
+ if (errno == EINTR)
+ goto retry;
+ return -1;
+ }
+ return ret;
+}
+
+
+static gnutls_anon_server_credentials_t vnc_tls_initialize_anon_cred(void)
+{
+ gnutls_anon_server_credentials_t anon_cred;
+ int ret;
+
+ if ((ret = gnutls_anon_allocate_server_credentials(&anon_cred)) < 0) {
+ VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
+ return NULL;
+ }
+
+ gnutls_anon_set_server_dh_params(anon_cred, dh_params);
+
+ return anon_cred;
+}
+
+
+static gnutls_certificate_credentials_t vnc_tls_initialize_x509_cred(VncDisplay *vd)
+{
+ gnutls_certificate_credentials_t x509_cred;
+ int ret;
+
+ if (!vd->tls.x509cacert) {
+ VNC_DEBUG("No CA x509 certificate specified\n");
+ return NULL;
+ }
+ if (!vd->tls.x509cert) {
+ VNC_DEBUG("No server x509 certificate specified\n");
+ return NULL;
+ }
+ if (!vd->tls.x509key) {
+ VNC_DEBUG("No server private key specified\n");
+ return NULL;
+ }
+
+ if ((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0) {
+ VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
+ return NULL;
+ }
+ if ((ret = gnutls_certificate_set_x509_trust_file(x509_cred,
+ vd->tls.x509cacert,
+ GNUTLS_X509_FMT_PEM)) < 0) {
+ VNC_DEBUG("Cannot load CA certificate %s\n", gnutls_strerror(ret));
+ gnutls_certificate_free_credentials(x509_cred);
+ return NULL;
+ }
+
+ if ((ret = gnutls_certificate_set_x509_key_file (x509_cred,
+ vd->tls.x509cert,
+ vd->tls.x509key,
+ GNUTLS_X509_FMT_PEM)) < 0) {
+ VNC_DEBUG("Cannot load certificate & key %s\n", gnutls_strerror(ret));
+ gnutls_certificate_free_credentials(x509_cred);
+ return NULL;
+ }
+
+ if (vd->tls.x509cacrl) {
+ if ((ret = gnutls_certificate_set_x509_crl_file(x509_cred,
+ vd->tls.x509cacrl,
+ GNUTLS_X509_FMT_PEM)) < 0) {
+ VNC_DEBUG("Cannot load CRL %s\n", gnutls_strerror(ret));
+ gnutls_certificate_free_credentials(x509_cred);
+ return NULL;
+ }
+ }
+
+ gnutls_certificate_set_dh_params (x509_cred, dh_params);
+
+ return x509_cred;
+}
+
+
+int vnc_tls_validate_certificate(VncState *vs)
+{
+ int ret;
+ unsigned int status;
+ const gnutls_datum_t *certs;
+ unsigned int nCerts, i;
+ time_t now;
+
+ VNC_DEBUG("Validating client certificate\n");
+ if ((ret = gnutls_certificate_verify_peers2 (vs->tls.session, &status)) < 0) {
+ VNC_DEBUG("Verify failed %s\n", gnutls_strerror(ret));
+ return -1;
+ }
+
+ if ((now = time(NULL)) == ((time_t)-1)) {
+ return -1;
+ }
+
+ if (status != 0) {
+ if (status & GNUTLS_CERT_INVALID)
+ VNC_DEBUG("The certificate is not trusted.\n");
+
+ if (status & GNUTLS_CERT_SIGNER_NOT_FOUND)
+ VNC_DEBUG("The certificate hasn't got a known issuer.\n");
+
+ if (status & GNUTLS_CERT_REVOKED)
+ VNC_DEBUG("The certificate has been revoked.\n");
+
+ if (status & GNUTLS_CERT_INSECURE_ALGORITHM)
+ VNC_DEBUG("The certificate uses an insecure algorithm\n");
+
+ return -1;
+ } else {
+ VNC_DEBUG("Certificate is valid!\n");
+ }
+
+ /* Only support x509 for now */
+ if (gnutls_certificate_type_get(vs->tls.session) != GNUTLS_CRT_X509)
+ return -1;
+
+ if (!(certs = gnutls_certificate_get_peers(vs->tls.session, &nCerts)))
+ return -1;
+
+ for (i = 0 ; i < nCerts ; i++) {
+ gnutls_x509_crt_t cert;
+ VNC_DEBUG ("Checking certificate chain %d\n", i);
+ if (gnutls_x509_crt_init (&cert) < 0)
+ return -1;
+
+ if (gnutls_x509_crt_import(cert, &certs[i], GNUTLS_X509_FMT_DER) < 0) {
+ gnutls_x509_crt_deinit (cert);
+ return -1;
+ }
+
+ if (gnutls_x509_crt_get_expiration_time (cert) < now) {
+ VNC_DEBUG("The certificate has expired\n");
+ gnutls_x509_crt_deinit (cert);
+ return -1;
+ }
+
+ if (gnutls_x509_crt_get_activation_time (cert) > now) {
+ VNC_DEBUG("The certificate is not yet activated\n");
+ gnutls_x509_crt_deinit (cert);
+ return -1;
+ }
+
+ if (gnutls_x509_crt_get_activation_time (cert) > now) {
+ VNC_DEBUG("The certificate is not yet activated\n");
+ gnutls_x509_crt_deinit (cert);
+ return -1;
+ }
+
+ if (i == 0) {
+ size_t dnameSize = 1024;
+ vs->tls.dname = g_malloc(dnameSize);
+ requery:
+ if ((ret = gnutls_x509_crt_get_dn (cert, vs->tls.dname, &dnameSize)) != 0) {
+ if (ret == GNUTLS_E_SHORT_MEMORY_BUFFER) {
+ vs->tls.dname = g_realloc(vs->tls.dname, dnameSize);
+ goto requery;
+ }
+ gnutls_x509_crt_deinit (cert);
+ VNC_DEBUG("Cannot get client distinguished name: %s",
+ gnutls_strerror (ret));
+ return -1;
+ }
+
+ if (vs->vd->tls.x509verify) {
+ int allow;
+ if (!vs->vd->tls.acl) {
+ VNC_DEBUG("no ACL activated, allowing access");
+ gnutls_x509_crt_deinit (cert);
+ continue;
+ }
+
+ allow = qemu_acl_party_is_allowed(vs->vd->tls.acl,
+ vs->tls.dname);
+
+ VNC_DEBUG("TLS x509 ACL check for %s is %s\n",
+ vs->tls.dname, allow ? "allowed" : "denied");
+ if (!allow) {
+ gnutls_x509_crt_deinit (cert);
+ return -1;
+ }
+ }
+ }
+
+ gnutls_x509_crt_deinit (cert);
+ }
+
+ return 0;
+}
+
+#if defined(GNUTLS_VERSION_NUMBER) && \
+ GNUTLS_VERSION_NUMBER >= 0x020200 /* 2.2.0 */
+
+static int vnc_set_gnutls_priority(gnutls_session_t s, int x509)
+{
+ const char *priority = x509 ? "NORMAL" : "NORMAL:+ANON-DH";
+ int rc;
+
+ rc = gnutls_priority_set_direct(s, priority, NULL);
+ if (rc != GNUTLS_E_SUCCESS) {
+ return -1;
+ }
+ return 0;
+}
+
+#else
+
+static int vnc_set_gnutls_priority(gnutls_session_t s, int x509)
+{
+ static const int cert_types[] = { GNUTLS_CRT_X509, 0 };
+ static const int protocols[] = {
+ GNUTLS_TLS1_1, GNUTLS_TLS1_0, GNUTLS_SSL3, 0
+ };
+ static const int kx_anon[] = { GNUTLS_KX_ANON_DH, 0 };
+ static const int kx_x509[] = {
+ GNUTLS_KX_DHE_DSS, GNUTLS_KX_RSA,
+ GNUTLS_KX_DHE_RSA, GNUTLS_KX_SRP, 0
+ };
+ int rc;
+
+ rc = gnutls_kx_set_priority(s, x509 ? kx_x509 : kx_anon);
+ if (rc != GNUTLS_E_SUCCESS) {
+ return -1;
+ }
+
+ rc = gnutls_certificate_type_set_priority(s, cert_types);
+ if (rc != GNUTLS_E_SUCCESS) {
+ return -1;
+ }
+
+ rc = gnutls_protocol_set_priority(s, protocols);
+ if (rc != GNUTLS_E_SUCCESS) {
+ return -1;
+ }
+ return 0;
+}
+
+#endif
+
+int vnc_tls_client_setup(VncState *vs,
+ int needX509Creds) {
+ VNC_DEBUG("Do TLS setup\n");
+ if (vnc_tls_initialize() < 0) {
+ VNC_DEBUG("Failed to init TLS\n");
+ vnc_client_error(vs);
+ return -1;
+ }
+ if (vs->tls.session == NULL) {
+ if (gnutls_init(&vs->tls.session, GNUTLS_SERVER) < 0) {
+ vnc_client_error(vs);
+ return -1;
+ }
+
+ if (gnutls_set_default_priority(vs->tls.session) < 0) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ vnc_client_error(vs);
+ return -1;
+ }
+
+ if (vnc_set_gnutls_priority(vs->tls.session, needX509Creds) < 0) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ vnc_client_error(vs);
+ return -1;
+ }
+
+ if (needX509Creds) {
+ gnutls_certificate_server_credentials x509_cred =
+ vnc_tls_initialize_x509_cred(vs->vd);
+ if (!x509_cred) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ vnc_client_error(vs);
+ return -1;
+ }
+ if (gnutls_credentials_set(vs->tls.session,
+ GNUTLS_CRD_CERTIFICATE, x509_cred) < 0) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ gnutls_certificate_free_credentials(x509_cred);
+ vnc_client_error(vs);
+ return -1;
+ }
+ if (vs->vd->tls.x509verify) {
+ VNC_DEBUG("Requesting a client certificate\n");
+ gnutls_certificate_server_set_request(vs->tls.session,
+ GNUTLS_CERT_REQUEST);
+ }
+
+ } else {
+ gnutls_anon_server_credentials_t anon_cred =
+ vnc_tls_initialize_anon_cred();
+ if (!anon_cred) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ vnc_client_error(vs);
+ return -1;
+ }
+ if (gnutls_credentials_set(vs->tls.session,
+ GNUTLS_CRD_ANON, anon_cred) < 0) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ gnutls_anon_free_server_credentials(anon_cred);
+ vnc_client_error(vs);
+ return -1;
+ }
+ }
+
+ gnutls_transport_set_ptr(vs->tls.session, (gnutls_transport_ptr_t)vs);
+ gnutls_transport_set_push_function(vs->tls.session, vnc_tls_push);
+ gnutls_transport_set_pull_function(vs->tls.session, vnc_tls_pull);
+ }
+ return 0;
+}
+
+
+void vnc_tls_client_cleanup(VncState *vs)
+{
+ if (vs->tls.session) {
+ gnutls_deinit(vs->tls.session);
+ vs->tls.session = NULL;
+ }
+ g_free(vs->tls.dname);
+}
+
+
+
+static int vnc_set_x509_credential(VncDisplay *vd,
+ const char *certdir,
+ const char *filename,
+ char **cred,
+ int ignoreMissing)
+{
+ struct stat sb;
+
+ g_free(*cred);
+ *cred = g_malloc(strlen(certdir) + strlen(filename) + 2);
+
+ strcpy(*cred, certdir);
+ strcat(*cred, "/");
+ strcat(*cred, filename);
+
+ VNC_DEBUG("Check %s\n", *cred);
+ if (stat(*cred, &sb) < 0) {
+ g_free(*cred);
+ *cred = NULL;
+ if (ignoreMissing && errno == ENOENT)
+ return 0;
+ return -1;
+ }
+
+ return 0;
+}
+
+
+int vnc_tls_set_x509_creds_dir(VncDisplay *vd,
+ const char *certdir)
+{
+ if (vnc_set_x509_credential(vd, certdir, X509_CA_CERT_FILE, &vd->tls.x509cacert, 0) < 0)
+ goto cleanup;
+ if (vnc_set_x509_credential(vd, certdir, X509_CA_CRL_FILE, &vd->tls.x509cacrl, 1) < 0)
+ goto cleanup;
+ if (vnc_set_x509_credential(vd, certdir, X509_SERVER_CERT_FILE, &vd->tls.x509cert, 0) < 0)
+ goto cleanup;
+ if (vnc_set_x509_credential(vd, certdir, X509_SERVER_KEY_FILE, &vd->tls.x509key, 0) < 0)
+ goto cleanup;
+
+ return 0;
+
+ cleanup:
+ g_free(vd->tls.x509cacert);
+ g_free(vd->tls.x509cacrl);
+ g_free(vd->tls.x509cert);
+ g_free(vd->tls.x509key);
+ vd->tls.x509cacert = vd->tls.x509cacrl = vd->tls.x509cert = vd->tls.x509key = NULL;
+ return -1;
+}
+
Code Review / kvmfornfv.git / blobdiff