X-Git-Url: https://git.sesse.net/?p=rdpsrv;a=blobdiff_plain;f=Xserver%2Fprograms%2FXserver%2Fhw%2Fvnc%2Fauth.c;fp=Xserver%2Fprograms%2FXserver%2Fhw%2Fvnc%2Fauth.c;h=e9a79770f0237a6fb2d517503b1bfbf8d3c0d565;hp=0000000000000000000000000000000000000000;hb=b6e6afccf37f4ad0515ef2a698f714fdf1bf23b3;hpb=e3340a110a3b01756b8e67531395a33b40a17d37

diff --git a/Xserver/programs/Xserver/hw/vnc/auth.c b/Xserver/programs/Xserver/hw/vnc/auth.c
new file mode 100644
index 0000000..e9a7977
--- /dev/null
+++ b/Xserver/programs/Xserver/hw/vnc/auth.c
@@ -0,0 +1,193 @@
+/*
+ * auth.c - deal with authentication.
+ *
+ * This file implements the VNC authentication protocol when setting up an RFB
+ * connection.
+ */
+
+/*
+ *  Copyright (C) 2002 RealVNC Ltd.
+ *  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
+ *
+ *  This is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This software is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this software; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ *  USA.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include "windowstr.h"
+#include "rfb.h"
+
+
+#define MAX_AUTH_TRIES 5
+#define AUTH_TOO_MANY_BASE_DELAY 10 * 1000 /* in ms, doubles for each failure
+					      over MAX_AUTH_TRIES */
+
+static int rfbAuthFailure();
+static CARD32 rfbAuthReenable(OsTimerPtr timer, CARD32 now, pointer arg);
+
+char *rfbAuthPasswdFile = NULL;
+int rfbAuthTries = 0;
+Bool rfbAuthTooManyTries = FALSE;
+static OsTimerPtr timer = NULL;
+
+
+/*
+ * rfbAuthNewClient is called when we reach the point of authenticating
+ * a new client.  If authentication isn't being used then we simply send
+ * rfbNoAuth.  Otherwise we send rfbVncAuth plus the challenge.
+ */
+
+void
+rfbAuthNewClient(cl)
+    rfbClientPtr cl;
+{
+    char buf[4 + CHALLENGESIZE];
+    int len;
+
+    cl->state = RFB_AUTHENTICATION;
+
+    if (rfbAuthPasswdFile && !cl->reverseConnection) {
+
+	if (rfbAuthTooManyTries) {
+	    rfbClientConnFailed(cl, "Too many authentication failures");
+	    return;
+	}
+
+	*(CARD32 *)buf = Swap32IfLE(rfbVncAuth);
+	vncRandomBytes(cl->authChallenge);
+	memcpy(&buf[4], (char *)cl->authChallenge, CHALLENGESIZE);
+	len = 4 + CHALLENGESIZE;
+
+    } else {
+
+	*(CARD32 *)buf = Swap32IfLE(rfbNoAuth);
+	len = 4;
+	cl->state = RFB_INITIALISATION;
+    }
+
+    if (WriteExact(cl->sock, buf, len) < 0) {
+	rfbLogPerror("rfbAuthNewClient: write");
+	rfbCloseSock(cl->sock);
+	return;
+    }
+}
+
+
+/*
+ * rfbAuthProcessClientMessage is called when the client sends its
+ * authentication response.
+ */
+
+void
+rfbAuthProcessClientMessage(cl)
+    rfbClientPtr cl;
+{
+    char *passwd;
+    int i, n;
+    CARD8 response[CHALLENGESIZE];
+    CARD32 authResult;
+
+    n = ReadExact(cl->sock, (char *)response, CHALLENGESIZE);
+
+    if (n <= 0) {
+	if (n == 0)
+            rfbLog("rfbAuthProcessClientMessage: read failed\n");
+        else
+	    rfbLogPerror("rfbAuthProcessClientMessage: read");
+        rfbAuthFailure();
+	rfbCloseSock(cl->sock);
+	return;
+    }
+
+    passwd = vncDecryptPasswdFromFile(rfbAuthPasswdFile);
+
+    if (passwd == NULL) {
+	rfbLog("rfbAuthProcessClientMessage: could not get password from %s\n",
+	       rfbAuthPasswdFile);
+
+	authResult = Swap32IfLE(rfbVncAuthFailed);
+
+	if (WriteExact(cl->sock, (char *)&authResult, 4) < 0) {
+	    rfbLogPerror("rfbAuthProcessClientMessage: write");
+	}
+	rfbCloseSock(cl->sock);
+	return;
+    }
+
+    vncEncryptBytes(cl->authChallenge, passwd);
+
+    /* Lose the password from memory */
+    for (i = strlen(passwd); i >= 0; i--) {
+	passwd[i] = '\0';
+    }
+
+    free((char *)passwd);
+
+    if (memcmp(cl->authChallenge, response, CHALLENGESIZE) != 0) {
+	rfbLog("rfbAuthProcessClientMessage: authentication failed from %s\n",
+	       cl->host);
+
+        authResult = rfbAuthFailure();
+        authResult = Swap32IfLE(authResult);
+
+	if (WriteExact(cl->sock, (char *)&authResult, 4) < 0) {
+	    rfbLogPerror("rfbAuthProcessClientMessage: write");
+	}
+	rfbCloseSock(cl->sock);
+	return;
+    }
+
+    rfbAuthTries = 0;
+
+    authResult = Swap32IfLE(rfbVncAuthOK);
+
+    if (WriteExact(cl->sock, (char *)&authResult, 4) < 0) {
+	rfbLogPerror("rfbAuthProcessClientMessage: write");
+	rfbCloseSock(cl->sock);
+	return;
+    }
+
+    cl->state = RFB_INITIALISATION;
+}
+
+
+static int rfbAuthFailure()
+{
+  int i;
+
+  rfbAuthTries++;
+
+  if (rfbAuthTries >= MAX_AUTH_TRIES) {
+
+    CARD32 delay = AUTH_TOO_MANY_BASE_DELAY;
+    for (i = MAX_AUTH_TRIES; i < rfbAuthTries; i++)
+      delay *= 2;
+    timer = TimerSet(timer, 0, delay, rfbAuthReenable, NULL);
+
+    rfbAuthTooManyTries = TRUE;
+    return rfbVncAuthTooMany;
+  }
+
+  return rfbVncAuthFailed;
+}
+
+
+static CARD32
+rfbAuthReenable(OsTimerPtr timer, CARD32 now, pointer arg)
+{
+    rfbAuthTooManyTries = FALSE;
+    return 0;
+}