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--- ./nx-X11/programs/Xserver/os/auth.c.X.original 2015-02-13 14:03:44.788440645 +0100
+++ ./nx-X11/programs/Xserver/os/auth.c 2015-02-10 19:13:13.452699065 +0100
@@ -28,6 +28,23 @@
*/
/* $XFree86: auth.c,v 1.13 2003/04/27 21:31:08 herrb Exp $ */
+/**************************************************************************/
+/* */
+/* Copyright (c) 2001, 2011 NoMachine, http://www.nomachine.com/. */
+/* */
+/* NX-X11, NX protocol compression and NX extensions to this software */
+/* are copyright of NoMachine. Redistribution and use of the present */
+/* software is allowed according to terms specified in the file LICENSE */
+/* which comes in the source distribution. */
+/* */
+/* Check http://www.nomachine.com/licensing.html for applicability. */
+/* */
+/* NX and NoMachine are trademarks of Medialogic S.p.A. */
+/* */
+/* All rights reserved. */
+/* */
+/**************************************************************************/
+
/*
* authorization hooks for the server
* Author: Keith Packard, MIT X Consortium
@@ -129,7 +146,24 @@
void
InitAuthorization (char *file_name)
{
+#ifdef __sun
+ char * envBuffer;
+#endif
authorization_file = file_name;
+#ifdef NX_TRANS_AUTH
+#ifdef NX_TRANS_TEST
+ fprintf(stderr, "InitAuthorization: Going to propagate auth file '%s' to the environment.\n",
+ authorization_file);
+#endif
+#ifdef __sun
+ envBuffer = malloc(15+strlen(authorization_file));
+ sprintf(envBuffer,"NX_XAUTHORITY=%s",authorization_file);
+ putenv(envBuffer);
+#else
+ setenv("NX_XAUTHORITY", authorization_file, 1);
+#endif
+#endif
+
}
static int
@@ -144,6 +178,68 @@
if (!authorization_file)
return 0;
+#ifdef NX_TRANS_AUTH
+
+ /*
+ * We think that the way LoadAuthorization() is working is wrong.
+ * It doesn't reset the list of stored authorizations before reading
+ * the new cookies. Our take is that if a new auth file is to be
+ * read, the only cookies that are to be accepted are those that are
+ * in the new file, not those in the file -plus- those that have
+ * been in the file in the past. Furthermore, if the list can't be
+ * read or it is empty, it should assume that it ignores which co-
+ * okies are valid and thus it should disable any access. Your mile-
+ * age can vary. A less draconian approach could be to leave the old
+ * cookies if the file can't be read and remove them only if the
+ * file is empty.
+ *
+ * Adding the cookies without removing the old values for the same
+ * protocol has an important implication. If an user shares the co-
+ * okie with somebody and later wants to revoke the access to the
+ * display, changing the cookie will not work. This is especially
+ * important with NX. For security reasons, after reconnecting the
+ * session to a different display, it is advisable to generate a
+ * new set of cookies, but doing that it is useless with the current
+ * code, as the old cookies are going to be still accepted. On the
+ * same topic, consider that once an user has got access to the X
+ * server, he/she can freely enable host authentication from any
+ * host, so the safe behaviour should be to reset the host based
+ * authenthication at least at reconnection, and keep as valid only
+ * the cookies that are actually in the file. This behaviour would
+ * surely break many applications, among them a SSH connection run
+ * inside a NX session, as ssh -X reads the cookie for the display
+ * only at session startup and does not read the cookies again
+ * when the auth file is changed.
+ *
+ * Another bug (or feature, depending on how you want to consider
+ * it) is that if the authority file contains entries for different
+ * displays (as it is the norm when the authority file is the default
+ * .Xauthority in the user's home), the server will match -any- of
+ * the cookies, even cookies that are not for its own display. This
+ * means that you have be careful when passing an authority file to
+ * nxagent or Xnest and maybe keep separate files for letting nxagent
+ * find the cookie to be used to connect to the remote display and
+ * for letting it find what cookies to accept. If the file is the
+ * same, clients will be able to connect to nxagent with both the
+ * cookies.
+ */
+
+#ifdef NX_TRANS_AUTH_RESET
+
+ #ifdef NX_TRANS_TEST
+ fprintf(stderr, "LoadAuthorization: Resetting authorization info.\n");
+ #endif
+
+ for (i = 0; i < NUM_AUTHORIZATION; i++) {
+ if (protocols[i].Reset) {
+ (*protocols[i].Reset) ();
+ }
+ }
+
+#endif
+
+#endif /* #ifdef NX_TRANS_AUTH */
+
f = Fopen (authorization_file, "r");
if (!f)
return -1;
@@ -154,6 +250,14 @@
memcmp (protocols[i].name, auth->name, (int) auth->name_length) == 0 &&
protocols[i].Add)
{
+#ifdef NX_TRANS_AUTH
+
+ #ifdef NX_TRANS_TEST
+ fprintf(stderr, "LoadAuthorization: Adding new record from file [%s].\n",
+ authorization_file);
+ #endif
+
+#endif
++count;
(*protocols[i].Add) (auth->data_length, auth->data,
FakeClientID(0));
@@ -162,7 +266,46 @@
XauDisposeAuth (auth);
}
+#ifdef NX_TRANS_AUTH
+
+ if (count == 0)
+ {
+ fprintf(stderr, "Warning: No authorization record could be read from file '%s'.\n",
+ authorization_file);
+
+ fprintf(stderr, "Warning: Please, create a valid authorization cookie using the command\n"
+ "Warning: 'xauth -f %s add <display> MIT-MAGIC-COOKIE-1 <cookie>'.\n",
+ authorization_file);
+ }
+
+#endif
+
+#ifdef NX_TRANS_AUTH
+ if (Fclose (f) != 0)
+ {
+ /*
+ * If the Fclose() fails, for example because of a signal,
+ * it's advisable to return the number of protocols read,
+ * if any, or otherwise the server would believe that no
+ * cookie is valid and eventually fall back to host based
+ * authentication. Note anyway that the new code in Check-
+ * Authorization() doesn't care the return value and gives
+ * a chance to the function to check the file at the next
+ * connection.
+ */
+
+ if (count > 0)
+ {
+ return count;
+ }
+ else
+ {
+ return -1;
+ }
+ }
+#else
Fclose (f);
+#endif
return count;
}
@@ -194,7 +337,10 @@
int i;
struct stat buf;
static time_t lastmod = 0;
+
+ #ifndef NX_TRANS_AUTH
static Bool loaded = FALSE;
+ #endif
if (!authorization_file || stat(authorization_file, &buf))
{
@@ -225,7 +371,67 @@
* entries for this server), and reloading it later fails, don't
* change anything. (loadauth == -1 && loaded)
*/
-
+
+#ifdef NX_TRANS_AUTH
+
+ /*
+ * The implementation of CheckAuthorization() was changed. The way
+ * the auth file was handled previously was questionable and could
+ * open the way to a vast array of security problems. There might be
+ * ways for an attacker to prevent the server from reading the file
+ * and it was enough for the server to fail reading the file once
+ * (because of a not blocked signal, for example) to leave the dis-
+ * play open to all the users running a session on the same terminal
+ * server.
+ *
+ * In NX we want to have only two cases: either we have to check an
+ * authorization file or we don't. In the first case we need to do our
+ * best to read the file at any new client access and never fall back
+ * to host based authentication. Falling back to local host access has
+ * no way back, as it will always take precedence over the auth cookie
+ * (unless the user explicitly disables, one by one, all the rules
+ * allowing local access, if and only if he/she becomes aware of the
+ * problem). In the second case we assume that user doesn't care secu-
+ * rity and so allow unrestricted access from the local machine.
+ */
+
+ #ifdef NX_TRANS_TEST
+ fprintf(stderr, "CheckAuthorization: Going to set authorization with loadauth [%d].\n",
+ loadauth);
+ #endif
+
+ if (authorization_file)
+ {
+ #ifdef NX_TRANS_TEST
+ fprintf(stderr, "CheckAuthorization: Disabling local host access.\n");
+ #endif
+
+ DisableLocalHost();
+ }
+ else
+ {
+ /*
+ * Enable host-based authentication only if
+ * the authorization file was not specified
+ * either on the command line or in the env-
+ * ironment.
+ */
+
+ #ifdef NX_TRANS_TEST
+ fprintf(stderr, "CheckAuthorization: Enabling local host access.\n");
+ #endif
+
+ EnableLocalHost();
+ }
+
+ /*
+ * Avoid the 'unused variable' warning.
+ */
+
+ loadauth = loadauth;
+
+#else /* #ifdef NX_TRANS_AUTH */
+
if (loadauth > 0)
{
DisableLocalHost(); /* got at least one */
@@ -233,6 +439,8 @@
}
else if (loadauth == 0 || !loaded)
EnableLocalHost ();
+
+#endif /* #ifdef NX_TRANS_AUTH */
}
if (name_length) {
for (i = 0; i < NUM_AUTHORIZATION; i++) {
|
