[Qemu-devel] [PATCH 1/3] Store VNC auth scheme per-client as well as per-server

[Daniel P. Berrange]

A future patch will introduce a situation where different
clients may have different authentication schemes set.
When a new client arrives, copy the 'auth' and 'subauth'
fields from VncDisplay into the client's VncState, and
use the latter in all authentication functions.

* ui/vnc.h: Add 'auth' and 'subauth' to VncState
* ui/vnc-auth-sasl.c, ui/vnc-auth-vencrypt.c,
  ui/vnc.c: Make auth functions pull auth scheme
  from VncState instead of VncDisplay
---
 ui/vnc-auth-sasl.c     |    8 ++++----
 ui/vnc-auth-vencrypt.c |   18 +++++++++---------
 ui/vnc.c               |   39 ++++++++++++++++++++++++++-------------
 ui/vnc.h               |    2 ++
 4 files changed, 41 insertions(+), 26 deletions(-)

diff --git a/ui/vnc-auth-sasl.c b/ui/vnc-auth-sasl.c
index 17a621a..8aac5ec 100644
--- a/ui/vnc-auth-sasl.c
+++ b/ui/vnc-auth-sasl.c
@@ -538,8 +538,8 @@ void start_auth_sasl(VncState *vs)
 
 #ifdef CONFIG_VNC_TLS
     /* Inform SASL that we've got an external SSF layer from TLS/x509 */
-    if (vs->vd->auth == VNC_AUTH_VENCRYPT &&
-        vs->vd->subauth == VNC_AUTH_VENCRYPT_X509SASL) {
+    if (vs->auth == VNC_AUTH_VENCRYPT &&
+        vs->subauth == VNC_AUTH_VENCRYPT_X509SASL) {
         gnutls_cipher_algorithm_t cipher;
         sasl_ssf_t ssf;
 
@@ -570,8 +570,8 @@ void start_auth_sasl(VncState *vs)
 #ifdef CONFIG_VNC_TLS
         /* Disable SSF, if using TLS+x509+SASL only. TLS without x509
            is not sufficiently strong */
-        || (vs->vd->auth == VNC_AUTH_VENCRYPT &&
-            vs->vd->subauth == VNC_AUTH_VENCRYPT_X509SASL)
+        || (vs->auth == VNC_AUTH_VENCRYPT &&
+            vs->subauth == VNC_AUTH_VENCRYPT_X509SASL)
 #endif /* CONFIG_VNC_TLS */
         ) {
         /* If we've got TLS or UNIX domain sock, we don't care about SSF */
diff --git a/ui/vnc-auth-vencrypt.c b/ui/vnc-auth-vencrypt.c
index 07c1691..674ba97 100644
--- a/ui/vnc-auth-vencrypt.c
+++ b/ui/vnc-auth-vencrypt.c
@@ -29,7 +29,7 @@
 
 static void start_auth_vencrypt_subauth(VncState *vs)
 {
-    switch (vs->vd->subauth) {
+    switch (vs->subauth) {
     case VNC_AUTH_VENCRYPT_TLSNONE:
     case VNC_AUTH_VENCRYPT_X509NONE:
        VNC_DEBUG("Accept TLS auth none\n");
@@ -51,7 +51,7 @@ static void start_auth_vencrypt_subauth(VncState *vs)
 #endif /* CONFIG_VNC_SASL */
 
     default: /* Should not be possible, but just in case */
-       VNC_DEBUG("Reject subauth %d server bug\n", vs->vd->auth);
+       VNC_DEBUG("Reject subauth %d server bug\n", vs->auth);
        vnc_write_u8(vs, 1);
        if (vs->minor >= 8) {
            static const char err[] = "Unsupported authentication type";
@@ -110,17 +110,17 @@ static void vnc_tls_handshake_io(void *opaque) {
 
 
 #define NEED_X509_AUTH(vs)                              \
-    ((vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509NONE ||   \
-     (vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509VNC ||    \
-     (vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509PLAIN ||  \
-     (vs)->vd->subauth == VNC_AUTH_VENCRYPT_X509SASL)
+    ((vs)->subauth == VNC_AUTH_VENCRYPT_X509NONE ||   \
+     (vs)->subauth == VNC_AUTH_VENCRYPT_X509VNC ||    \
+     (vs)->subauth == VNC_AUTH_VENCRYPT_X509PLAIN ||  \
+     (vs)->subauth == VNC_AUTH_VENCRYPT_X509SASL)
 
 
 static int protocol_client_vencrypt_auth(VncState *vs, uint8_t *data, size_t 
len)
 {
     int auth = read_u32(data, 0);
 
-    if (auth != vs->vd->subauth) {
+    if (auth != vs->subauth) {
         VNC_DEBUG("Rejecting auth %d\n", auth);
         vnc_write_u8(vs, 0); /* Reject auth */
         vnc_flush(vs);
@@ -153,10 +153,10 @@ static int protocol_client_vencrypt_init(VncState *vs, 
uint8_t *data, size_t len
         vnc_flush(vs);
         vnc_client_error(vs);
     } else {
-        VNC_DEBUG("Sending allowed auth %d\n", vs->vd->subauth);
+        VNC_DEBUG("Sending allowed auth %d\n", vs->subauth);
         vnc_write_u8(vs, 0); /* Accept version */
         vnc_write_u8(vs, 1); /* Number of sub-auths */
-        vnc_write_u32(vs, vs->vd->subauth); /* The supported auth */
+        vnc_write_u32(vs, vs->subauth); /* The supported auth */
         vnc_flush(vs);
         vnc_read_when(vs, protocol_client_vencrypt_auth, 4);
     }
diff --git a/ui/vnc.c b/ui/vnc.c
index 14f2930..39b5b51 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -2124,7 +2124,7 @@ static int protocol_client_auth(VncState *vs, uint8_t 
*data, size_t len)
 {
     /* We only advertise 1 auth scheme at a time, so client
      * must pick the one we sent. Verify this */
-    if (data[0] != vs->vd->auth) { /* Reject auth */
+    if (data[0] != vs->auth) { /* Reject auth */
        VNC_DEBUG("Reject auth %d because it didn't match advertized\n", 
(int)data[0]);
        vnc_write_u32(vs, 1);
        if (vs->minor >= 8) {
@@ -2135,7 +2135,7 @@ static int protocol_client_auth(VncState *vs, uint8_t 
*data, size_t len)
        vnc_client_error(vs);
     } else { /* Accept requested auth */
        VNC_DEBUG("Client requested auth %d\n", (int)data[0]);
-       switch (vs->vd->auth) {
+       switch (vs->auth) {
        case VNC_AUTH_NONE:
            VNC_DEBUG("Accept auth none\n");
            if (vs->minor >= 8) {
@@ -2165,7 +2165,7 @@ static int protocol_client_auth(VncState *vs, uint8_t 
*data, size_t len)
 #endif /* CONFIG_VNC_SASL */
 
        default: /* Should not be possible, but just in case */
-           VNC_DEBUG("Reject auth %d server code bug\n", vs->vd->auth);
+           VNC_DEBUG("Reject auth %d server code bug\n", vs->auth);
            vnc_write_u8(vs, 1);
            if (vs->minor >= 8) {
                static const char err[] = "Authentication failed";
@@ -2210,26 +2210,26 @@ static int protocol_version(VncState *vs, uint8_t 
*version, size_t len)
         vs->minor = 3;
 
     if (vs->minor == 3) {
-        if (vs->vd->auth == VNC_AUTH_NONE) {
+        if (vs->auth == VNC_AUTH_NONE) {
             VNC_DEBUG("Tell client auth none\n");
-            vnc_write_u32(vs, vs->vd->auth);
+            vnc_write_u32(vs, vs->auth);
             vnc_flush(vs);
             start_client_init(vs);
-       } else if (vs->vd->auth == VNC_AUTH_VNC) {
+       } else if (vs->auth == VNC_AUTH_VNC) {
             VNC_DEBUG("Tell client VNC auth\n");
-            vnc_write_u32(vs, vs->vd->auth);
+            vnc_write_u32(vs, vs->auth);
             vnc_flush(vs);
             start_auth_vnc(vs);
        } else {
-            VNC_DEBUG("Unsupported auth %d for protocol 3.3\n", vs->vd->auth);
+            VNC_DEBUG("Unsupported auth %d for protocol 3.3\n", vs->auth);
             vnc_write_u32(vs, VNC_AUTH_INVALID);
             vnc_flush(vs);
             vnc_client_error(vs);
        }
     } else {
-        VNC_DEBUG("Telling client we support auth %d\n", vs->vd->auth);
+        VNC_DEBUG("Telling client we support auth %d\n", vs->auth);
         vnc_write_u8(vs, 1); /* num auth */
-        vnc_write_u8(vs, vs->vd->auth);
+        vnc_write_u8(vs, vs->auth);
         vnc_read_when(vs, protocol_client_auth, 1);
         vnc_flush(vs);
     }
@@ -2494,12 +2494,25 @@ static void vnc_remove_timer(VncDisplay *vd)
     }
 }
 
-static void vnc_connect(VncDisplay *vd, int csock)
+static void vnc_connect(VncDisplay *vd, int csock, int skipauth)
 {
     VncState *vs = qemu_mallocz(sizeof(VncState));
     int i;
 
     vs->csock = csock;
+
+    if (skipauth) {
+       vs->auth = VNC_AUTH_NONE;
+#ifdef CONFIG_VNC_TLS
+       vs->subauth = VNC_AUTH_INVALID;
+#endif
+    } else {
+       vs->auth = vd->auth;
+#ifdef CONFIG_VNC_TLS
+       vs->subauth = vd->subauth;
+#endif
+    }
+
     vs->lossy_rect = qemu_mallocz(VNC_STAT_ROWS * sizeof (*vs->lossy_rect));
     for (i = 0; i < VNC_STAT_ROWS; ++i) {
         vs->lossy_rect[i] = qemu_mallocz(VNC_STAT_COLS * sizeof (uint8_t));
@@ -2557,7 +2570,7 @@ static void vnc_listen_read(void *opaque)
 
     int csock = qemu_accept(vs->lsock, (struct sockaddr *)&addr, &addrlen);
     if (csock != -1) {
-        vnc_connect(vs, csock);
+        vnc_connect(vs, csock, 0);
     }
 }
 
@@ -2887,7 +2900,7 @@ int vnc_display_open(DisplayState *ds, const char 
*display)
         } else {
             int csock = vs->lsock;
             vs->lsock = -1;
-            vnc_connect(vs, csock);
+            vnc_connect(vs, csock, 0);
         }
         return 0;
 
diff --git a/ui/vnc.h b/ui/vnc.h
index f10c5dc..66689f1 100644
--- a/ui/vnc.h
+++ b/ui/vnc.h
@@ -256,8 +256,10 @@ struct VncState
     int major;
     int minor;
 
+    int auth;
     char challenge[VNC_AUTH_CHALLENGE_SIZE];
 #ifdef CONFIG_VNC_TLS
+    int subauth; /* Used by VeNCrypt */
     VncStateTLS tls;
 #endif
 #ifdef CONFIG_VNC_SASL
-- 
1.7.4.4