ui: convert VNC server to use QCryptoTLSSession

Switch VNC server over to using the QCryptoTLSSession object
for the TLS session. This removes the direct use of gnutls
from the VNC server code. It also removes most knowledge
about TLS certificate handling from the VNC server code.
This has the nice effect that all the CONFIG_VNC_TLS
conditionals go away and the user gets an actual error
message when requesting TLS instead of it being silently
ignored.

With this change, the existing configuration options for
enabling TLS with -vnc are deprecated.

Old syntax for anon-DH credentials:

  -vnc hostname:0,tls

New syntax:

  -object tls-creds-anon,id=tls0,endpoint=server \
  -vnc hostname:0,tls-creds=tls0

Old syntax for x509 credentials, no client certs:

  -vnc hostname:0,tls,x509=/path/to/certs

New syntax:

  -object tls-creds-x509,id=tls0,dir=/path/to/certs,endpoint=server,verify-peer=no \
  -vnc hostname:0,tls-creds=tls0

Old syntax for x509 credentials, requiring client certs:

  -vnc hostname:0,tls,x509verify=/path/to/certs

New syntax:

  -object tls-creds-x509,id=tls0,dir=/path/to/certs,endpoint=server,verify-peer=yes \
  -vnc hostname:0,tls-creds=tls0

This aligns VNC with the way TLS credentials are to be
configured in the future for chardev, nbd and migration
backends. It also has the benefit that the same TLS
credentials can be shared across multiple VNC server
instances, if desired.

If someone uses the deprecated syntax, it will internally
result in the creation of a 'tls-creds' object with an ID
based on the VNC server ID. This allows backwards compat
with the CLI syntax, while still deleting all the original
TLS code from the VNC server.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

1 files changed, 6 insertions, 9 deletions

diff --git a/ui/vnc.h b/ui/vnc.h
index 194ccf74f8..4dd769cddb 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -33,6 +33,7 @@
 #include "ui/console.h"
 #include "audio/audio.h"
 #include "qemu/bitmap.h"
+#include "crypto/tlssession.h"
 #include <zlib.h>
 #include <stdbool.h>
 
@@ -101,10 +102,7 @@ typedef void VncSendHextileTile(VncState *vs,
 
 typedef struct VncDisplay VncDisplay;
 
-#ifdef CONFIG_VNC_TLS
-#include "vnc-tls.h"
 #include "vnc-auth-vencrypt.h"
-#endif
 #ifdef CONFIG_VNC_SASL
 #include "vnc-auth-sasl.h"
 #endif
@@ -181,9 +179,8 @@ struct VncDisplay
     bool ws_tls; /* Used by websockets */
     bool lossy;
     bool non_adaptive;
-#ifdef CONFIG_VNC_TLS
-    VncDisplayTLS tls;
-#endif
+    QCryptoTLSCreds *tlscreds;
+    char *tlsaclname;
 #ifdef CONFIG_VNC_SASL
     VncDisplaySASL sasl;
 #endif
@@ -284,9 +281,7 @@ struct VncState
     int auth;
     int subauth; /* Used by VeNCrypt */
     char challenge[VNC_AUTH_CHALLENGE_SIZE];
-#ifdef CONFIG_VNC_TLS
-    VncStateTLS tls;
-#endif
+    QCryptoTLSSession *tls;
 #ifdef CONFIG_VNC_SASL
     VncStateSASL sasl;
 #endif
@@ -515,6 +510,8 @@ void vnc_client_write(void *opaque);
 
 ssize_t vnc_client_read_buf(VncState *vs, uint8_t *data, size_t datalen);
 ssize_t vnc_client_write_buf(VncState *vs, const uint8_t *data, size_t datalen);
+ssize_t vnc_tls_pull(char *buf, size_t len, void *opaque);
+ssize_t vnc_tls_push(const char *buf, size_t len, void *opaque);
 
 /* Protocol I/O functions */
 void vnc_write(VncState *vs, const void *data, size_t len);