From d40db7cd3cfd12256f0751af630540930e814393 Mon Sep 17 00:00:00 2001
From: Michael Jumper <mjumper@apache.org>
Date: Wed, 2 Dec 2020 22:55:16 -0800
Subject: [PATCH] GUACAMOLE-1227: Build support for generic VNC credentials
 only if supported by libvncclient.

---
 configure.ac             | 28 ++++++++++++++++++++++++++++
 src/protocols/vnc/auth.c |  2 ++
 src/protocols/vnc/auth.h |  2 ++
 src/protocols/vnc/vnc.c  |  2 ++
 4 files changed, 34 insertions(+)

diff --git a/configure.ac b/configure.ac
index e23003ff..ffd0e233 100644
--- a/configure.ac
+++ b/configure.ac
@@ -572,6 +572,34 @@ then
 
 fi
 
+#
+# Generic credential support within libVNCServer (authentication beyond
+# basic, standard VNC passwords)
+#
+
+if test "x${have_libvncserver}" = "xyes"
+then
+
+    have_vnc_creds=yes
+    AC_CHECK_MEMBERS([rfbClient.GetCredential],
+                     [], [have_vnc_creds=no],
+                     [[#include <rfb/rfbclient.h>]])
+
+    if test "x${have_vnc_creds}" = "xno"
+    then
+        AC_MSG_WARN([
+      --------------------------------------------
+       No generic credential support found in libvncclient.
+       VNC authentication support will be limited to passwords.
+      --------------------------------------------])
+    else
+        AC_DEFINE([ENABLE_VNC_GENERIC_CREDENTIALS],,
+                  [Whether support for generic VNC credentials is available.])
+    fi
+
+fi
+
+
 #
 # FreeRDP 2 (libfreerdp2, libfreerdp-client2, and libwinpr2)
 #
diff --git a/src/protocols/vnc/auth.c b/src/protocols/vnc/auth.c
index c26e4d2e..45dacb64 100644
--- a/src/protocols/vnc/auth.c
+++ b/src/protocols/vnc/auth.c
@@ -63,6 +63,7 @@ char* guac_vnc_get_password(rfbClient* client) {
     
 }
 
+#ifdef ENABLE_VNC_GENERIC_CREDENTIALS
 rfbCredential* guac_vnc_get_credentials(rfbClient* client, int credentialType) {
     
     guac_client* gc = rfbClientGetClientData(client, GUAC_VNC_CLIENT_KEY);
@@ -117,3 +118,4 @@ rfbCredential* guac_vnc_get_credentials(rfbClient* client, int credentialType) {
     return NULL;
     
 }
+#endif
diff --git a/src/protocols/vnc/auth.h b/src/protocols/vnc/auth.h
index 155a48db..46793b46 100644
--- a/src/protocols/vnc/auth.h
+++ b/src/protocols/vnc/auth.h
@@ -38,6 +38,7 @@
  */
 char* guac_vnc_get_password(rfbClient* client);
 
+#ifdef ENABLE_VNC_GENERIC_CREDENTIALS
 /**
  * Callback which is invoked by libVNCServer when it needs to read the user's
  * VNC credentials.  The credentials are stored in the connection settings,
@@ -55,6 +56,7 @@ char* guac_vnc_get_password(rfbClient* client);
  *     The rfbCredential object that contains the required credentials.
  */
 rfbCredential* guac_vnc_get_credentials(rfbClient* client, int credentialType);
+#endif
 
 #endif
 
diff --git a/src/protocols/vnc/vnc.c b/src/protocols/vnc/vnc.c
index 33bd5c59..a310e515 100644
--- a/src/protocols/vnc/vnc.c
+++ b/src/protocols/vnc/vnc.c
@@ -154,8 +154,10 @@ rfbClient* guac_vnc_get_client(guac_client* client) {
 
     }
 
+#ifdef ENABLE_VNC_GENERIC_CREDENTIALS
     /* Authentication */
     rfb_client->GetCredential = guac_vnc_get_credentials;
+#endif
     
     /* Password */
     rfb_client->GetPassword = guac_vnc_get_password;