GUAC-363: Set preconnection BLOB and ID if supported by FreeRDP and specified within connection parameters.

configure.ac

@@ -609,6 +609,7 @@ then
                       rdpSettings.Height,
                       rdpSettings.FastPathInput,
                       rdpSettings.FastPathOutput,
+                      rdpSettings.SendPreconnectionPdu,
                       rdpSettings.OrderSupport],
                      [rdpsettings_interface=stable],,
                      [[#include <freerdp/freerdp.h>]])

src/protocols/rdp/client.c

@@ -129,6 +129,8 @@ const char* GUAC_CLIENT_ARGS[] = {
     "enable-full-window-drag",
     "enable-desktop-composition",
     "enable-menu-animations",
+    "preconnection-id",
+    "preconnection-blob",
 
 #ifdef ENABLE_COMMON_SSH
     "enable-sftp",
@@ -178,6 +180,8 @@ enum RDP_ARGS_IDX {
     IDX_ENABLE_FULL_WINDOW_DRAG,
     IDX_ENABLE_DESKTOP_COMPOSITION,
     IDX_ENABLE_MENU_ANIMATIONS,
+    IDX_PRECONNECTION_ID,
+    IDX_PRECONNECTION_BLOB,
 
 #ifdef ENABLE_COMMON_SSH
     IDX_ENABLE_SFTP,
@@ -773,6 +777,33 @@ int guac_client_init(guac_client* client, int argc, char** argv) {
                 argv[IDX_WIDTH], settings->color_depth);
     }
 
+    /* Preconnection ID */
+    settings->preconnection_id = -1;
+    if (argv[IDX_PRECONNECTION_ID][0] != '\0') {
+        settings->preconnection_id = atoi(argv[IDX_PRECONNECTION_ID]);
+        guac_client_log(client, GUAC_LOG_DEBUG,
+                "Preconnection ID: %i", settings->preconnection_id);
+    }
+
+    /* Preconnection BLOB */
+    settings->preconnection_blob = NULL;
+    if (argv[IDX_PRECONNECTION_BLOB][0] != '\0') {
+        settings->preconnection_blob = strdup(argv[IDX_PRECONNECTION_BLOB]);
+        guac_client_log(client, GUAC_LOG_DEBUG,
+                "Preconnection BLOB: \"%s\"", settings->preconnection_blob);
+    }
+
+#ifndef HAVE_RDPSETTINGS_SENDPRECONNECTIONPDU
+    /* Warn if support for the preconnection BLOB / ID is absent */
+    if (settings->preconnection_blob != NULL
+            || settings->preconnection_id != -1) {
+        guac_client_log(client, GUAC_LOG_WARNING,
+                "Installed version of FreeRDP lacks support for the "
+                "preconnection PDU. The specified preconnection BLOB and/or "
+                "ID will be ignored.");
+    }
+#endif
+
     /* Audio enable/disable */
     guac_client_data->settings.audio_enabled =
         (strcmp(argv[IDX_DISABLE_AUDIO], "true") != 0);

src/protocols/rdp/rdp_settings.c

@@ -292,6 +292,22 @@ void guac_rdp_push_settings(guac_rdp_settings* guac_settings, freerdp* rdp) {
 #endif
     }
 
+#ifdef HAVE_RDPSETTINGS_SENDPRECONNECTIONPDU
+    /* Preconnection ID */
+    if (guac_settings->preconnection_id != -1) {
+        rdp_settings->NegotiateSecurityLayer = FALSE;
+        rdp_settings->SendPreconnectionPdu = TRUE;
+        rdp_settings->PreconnectionId = guac_settings->preconnection_id;
+    }
+
+    /* Preconnection BLOB */
+    if (guac_settings->preconnection_blob != NULL) {
+        rdp_settings->NegotiateSecurityLayer = FALSE;
+        rdp_settings->SendPreconnectionPdu = TRUE;
+        rdp_settings->PreconnectionBlob = guac_settings->preconnection_blob;
+    }
+#endif
+
     /* Order support */
 #ifdef LEGACY_RDPSETTINGS
     bitmap_cache = rdp_settings->bitmap_cache;

src/protocols/rdp/rdp_settings.h

@@ -266,6 +266,20 @@ typedef struct guac_rdp_settings {
      */
     int menu_animations_enabled;
 
+    /**
+     * The preconnection ID to send within the preconnection PDU when
+     * initiating an RDP connection, if any. If no preconnection ID is
+     * specified, this will be -1.
+     */
+    int preconnection_id;
+
+    /**
+     * The preconnection BLOB (PCB) to send to the RDP server prior to full RDP
+     * connection negotiation. This value is used by Hyper-V to select the
+     * destination VM.
+     */
+    char* preconnection_blob;
+
 } guac_rdp_settings;
 
 /**