vns/tls: don't use depricated gnutls functions

Avoid using deprecated gnutls functions with recent gnutls versions.
Fixes build failure on Fedora 16.  Keep the old way for compatibility
with old installations such as RHEL-5 (gnutls 1.4.x).

Based on a patch from Raghavendra D Prabhu <raghu.prabhu13@gmail.com>
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

ui/vnc-tls.c

@@ -283,13 +283,57 @@ int vnc_tls_validate_certificate(struct VncState *vs)
     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(struct VncState *vs,
                          int needX509Creds) {
-    static const int cert_type_priority[] = { GNUTLS_CRT_X509, 0 };
-    static const int protocol_priority[]= { 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};
 
     VNC_DEBUG("Do TLS setup\n");
     if (vnc_tls_initialize() < 0) {
@@ -310,21 +354,7 @@ int vnc_tls_client_setup(struct VncState *vs,
             return -1;
         }
 
-        if (gnutls_kx_set_priority(vs->tls.session, needX509Creds ? kx_x509 : kx_anon) < 0) {
-            gnutls_deinit(vs->tls.session);
-            vs->tls.session = NULL;
-            vnc_client_error(vs);
-            return -1;
-        }
-
-        if (gnutls_certificate_type_set_priority(vs->tls.session, cert_type_priority) < 0) {
-            gnutls_deinit(vs->tls.session);
-            vs->tls.session = NULL;
-            vnc_client_error(vs);
-            return -1;
-        }
-
-        if (gnutls_protocol_set_priority(vs->tls.session, protocol_priority) < 0) {
+        if (vnc_set_gnutls_priority(vs->tls.session, needX509Creds) < 0) {
             gnutls_deinit(vs->tls.session);
             vs->tls.session = NULL;
             vnc_client_error(vs);