crypto: introduce new module for TLS x509 credentials

Introduce a QCryptoTLSCredsX509 class which is used to
manage x509 certificate TLS credentials. This will be
the preferred credential type offering strong security
characteristics

Example CLI configuration:

 $QEMU -object tls-creds-x509,id=tls0,endpoint=server,\
               dir=/path/to/creds/dir,verify-peer=yes

The 'id' value in the -object args will be used to associate the
credentials with the network services. For example, when the VNC
server is later converted it would use

 $QEMU -object tls-creds-x509,id=tls0,.... \
       -vnc 127.0.0.1:1,tls-creds=tls0

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/crypto/tlscredsx509.c b/crypto/tlscredsx509.c
new file mode 100644
index 0000000..6cc7b53
--- /dev/null
+++ b/crypto/tlscredsx509.c
@@ -0,0 +1,263 @@
+/*
+ * QEMU crypto TLS x509 credential support
+ *
+ * Copyright (c) 2015 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "crypto/tlscredsx509.h"
+#include "crypto/tlscredspriv.h"
+#include "qom/object_interfaces.h"
+#include "trace.h"
+
+
+#ifdef CONFIG_GNUTLS
+
+
+static int
+qcrypto_tls_creds_x509_load(QCryptoTLSCredsX509 *creds,
+                            Error **errp)
+{
+    char *cacert = NULL, *cacrl = NULL, *cert = NULL,
+        *key = NULL, *dhparams = NULL;
+    int ret;
+    int rv = -1;
+
+    trace_qcrypto_tls_creds_x509_load(creds,
+            creds->parent_obj.dir ? creds->parent_obj.dir : "<nodir>");
+
+    if (creds->parent_obj.endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
+        if (qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_CA_CERT,
+                                       true, &cacert, errp) < 0 ||
+            qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_CA_CRL,
+                                       false, &cacrl, errp) < 0 ||
+            qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_SERVER_CERT,
+                                       true, &cert, errp) < 0 ||
+            qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_SERVER_KEY,
+                                       true, &key, errp) < 0 ||
+            qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_DH_PARAMS,
+                                       false, &dhparams, errp) < 0) {
+            goto cleanup;
+        }
+    } else {
+        if (qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_CA_CERT,
+                                       true, &cacert, errp) < 0 ||
+            qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_CLIENT_CERT,
+                                       false, &cert, errp) < 0 ||
+            qcrypto_tls_creds_get_path(&creds->parent_obj,
+                                       QCRYPTO_TLS_CREDS_X509_CLIENT_KEY,
+                                       false, &key, errp) < 0) {
+            goto cleanup;
+        }
+    }
+
+    ret = gnutls_certificate_allocate_credentials(&creds->data);
+    if (ret < 0) {
+        error_setg(errp, "Cannot allocate credentials: '%s'",
+                   gnutls_strerror(ret));
+        goto cleanup;
+    }
+
+    ret = gnutls_certificate_set_x509_trust_file(creds->data,
+                                                 cacert,
+                                                 GNUTLS_X509_FMT_PEM);
+    if (ret < 0) {
+        error_setg(errp, "Cannot load CA certificate '%s': %s",
+                   cacert, gnutls_strerror(ret));
+        goto cleanup;
+    }
+
+    if (cert != NULL && key != NULL) {
+        ret = gnutls_certificate_set_x509_key_file(creds->data,
+                                                   cert, key,
+                                                   GNUTLS_X509_FMT_PEM);
+        if (ret < 0) {
+            error_setg(errp, "Cannot load certificate '%s' & key '%s': %s",
+                       cert, key, gnutls_strerror(ret));
+            goto cleanup;
+        }
+    }
+
+    if (cacrl != NULL) {
+        ret = gnutls_certificate_set_x509_crl_file(creds->data,
+                                                   cacrl,
+                                                   GNUTLS_X509_FMT_PEM);
+        if (ret < 0) {
+            error_setg(errp, "Cannot load CRL '%s': %s",
+                       cacrl, gnutls_strerror(ret));
+            goto cleanup;
+        }
+    }
+
+    if (creds->parent_obj.endpoint == QCRYPTO_TLS_CREDS_ENDPOINT_SERVER) {
+        if (qcrypto_tls_creds_get_dh_params_file(&creds->parent_obj, dhparams,
+                                                 &creds->parent_obj.dh_params,
+                                                 errp) < 0) {
+            goto cleanup;
+        }
+        gnutls_certificate_set_dh_params(creds->data,
+                                         creds->parent_obj.dh_params);
+    }
+
+    rv = 0;
+ cleanup:
+    g_free(cacert);
+    g_free(cacrl);
+    g_free(cert);
+    g_free(key);
+    g_free(dhparams);
+    return rv;
+}
+
+
+static void
+qcrypto_tls_creds_x509_unload(QCryptoTLSCredsX509 *creds)
+{
+    if (creds->data) {
+        gnutls_certificate_free_credentials(creds->data);
+        creds->data = NULL;
+    }
+}
+
+
+#else /* ! CONFIG_GNUTLS */
+
+
+static void
+qcrypto_tls_creds_x509_load(QCryptoTLSCredsX509 *creds G_GNUC_UNUSED,
+                            Error **errp)
+{
+    error_setg(errp, "TLS credentials support requires GNUTLS");
+}
+
+
+static void
+qcrypto_tls_creds_x509_unload(QCryptoTLSCredsX509 *creds G_GNUC_UNUSED)
+{
+    /* nada */
+}
+
+
+#endif /* ! CONFIG_GNUTLS */
+
+
+static void
+qcrypto_tls_creds_x509_prop_set_loaded(Object *obj,
+                                       bool value,
+                                       Error **errp)
+{
+    QCryptoTLSCredsX509 *creds = QCRYPTO_TLS_CREDS_X509(obj);
+
+    if (value) {
+        qcrypto_tls_creds_x509_load(creds, errp);
+    } else {
+        qcrypto_tls_creds_x509_unload(creds);
+    }
+}
+
+
+#ifdef CONFIG_GNUTLS
+
+
+static bool
+qcrypto_tls_creds_x509_prop_get_loaded(Object *obj,
+                                       Error **errp G_GNUC_UNUSED)
+{
+    QCryptoTLSCredsX509 *creds = QCRYPTO_TLS_CREDS_X509(obj);
+
+    return creds->data != NULL;
+}
+
+
+#else /* ! CONFIG_GNUTLS */
+
+
+static bool
+qcrypto_tls_creds_x509_prop_get_loaded(Object *obj G_GNUC_UNUSED,
+                                       Error **errp G_GNUC_UNUSED)
+{
+    return false;
+}
+
+
+#endif /* ! CONFIG_GNUTLS */
+
+
+static void
+qcrypto_tls_creds_x509_complete(UserCreatable *uc, Error **errp)
+{
+    object_property_set_bool(OBJECT(uc), true, "loaded", errp);
+}
+
+
+static void
+qcrypto_tls_creds_x509_init(Object *obj)
+{
+    object_property_add_bool(obj, "loaded",
+                             qcrypto_tls_creds_x509_prop_get_loaded,
+                             qcrypto_tls_creds_x509_prop_set_loaded,
+                             NULL);
+}
+
+
+static void
+qcrypto_tls_creds_x509_finalize(Object *obj)
+{
+    QCryptoTLSCredsX509 *creds = QCRYPTO_TLS_CREDS_X509(obj);
+
+    qcrypto_tls_creds_x509_unload(creds);
+}
+
+
+static void
+qcrypto_tls_creds_x509_class_init(ObjectClass *oc, void *data)
+{
+    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+    ucc->complete = qcrypto_tls_creds_x509_complete;
+}
+
+
+static const TypeInfo qcrypto_tls_creds_x509_info = {
+    .parent = TYPE_QCRYPTO_TLS_CREDS,
+    .name = TYPE_QCRYPTO_TLS_CREDS_X509,
+    .instance_size = sizeof(QCryptoTLSCredsX509),
+    .instance_init = qcrypto_tls_creds_x509_init,
+    .instance_finalize = qcrypto_tls_creds_x509_finalize,
+    .class_size = sizeof(QCryptoTLSCredsX509Class),
+    .class_init = qcrypto_tls_creds_x509_class_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_USER_CREATABLE },
+        { }
+    }
+};
+
+
+static void
+qcrypto_tls_creds_x509_register_types(void)
+{
+    type_register_static(&qcrypto_tls_creds_x509_info);
+}
+
+
+type_init(qcrypto_tls_creds_x509_register_types);