- djm@cvs.openbsd.org 2005/07/04 00:58:43
[channels.c clientloop.c clientloop.h misc.c misc.h ssh.c ssh_config.5]
implement support for X11 and agent forwarding over multiplex slave
connections. Because of protocol limitations, the slave connections inherit
the master's DISPLAY and SSH_AUTH_SOCK rather than distinctly forwarding
their own.
ok dtucker@ "put it in" deraadt@
diff --git a/channels.c b/channels.c
index b589023..14ff166 100644
--- a/channels.c
+++ b/channels.c
@@ -39,7 +39,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.218 2005/07/01 13:19:47 markus Exp $");
+RCSID("$OpenBSD: channels.c,v 1.219 2005/07/04 00:58:42 djm Exp $");
#include "ssh.h"
#include "ssh1.h"
@@ -111,6 +111,9 @@
/* Maximum number of fake X11 displays to try. */
#define MAX_DISPLAYS 1000
+/* Saved X11 local (client) display. */
+static char *x11_saved_display = NULL;
+
/* Saved X11 authentication protocol name. */
static char *x11_saved_proto = NULL;
@@ -2955,12 +2958,18 @@
const char *proto, const char *data)
{
u_int data_len = (u_int) strlen(data) / 2;
- u_int i, value, len;
+ u_int i, value;
char *new_data;
int screen_number;
const char *cp;
u_int32_t rnd = 0;
+ if (x11_saved_display && strcmp(disp, x11_saved_display) != 0) {
+ error("x11_request_forwarding_with_spoofing: different "
+ "$DISPLAY already forwarded");
+ return;
+ }
+
cp = disp;
if (disp)
cp = strchr(disp, ':');
@@ -2971,33 +2980,31 @@
else
screen_number = 0;
- /* Save protocol name. */
- x11_saved_proto = xstrdup(proto);
-
- /*
- * Extract real authentication data and generate fake data of the
- * same length.
- */
- x11_saved_data = xmalloc(data_len);
- x11_fake_data = xmalloc(data_len);
- for (i = 0; i < data_len; i++) {
- if (sscanf(data + 2 * i, "%2x", &value) != 1)
- fatal("x11_request_forwarding: bad authentication data: %.100s", data);
- if (i % 4 == 0)
- rnd = arc4random();
- x11_saved_data[i] = value;
- x11_fake_data[i] = rnd & 0xff;
- rnd >>= 8;
+ if (x11_saved_proto == NULL) {
+ /* Save protocol name. */
+ x11_saved_proto = xstrdup(proto);
+ /*
+ * Extract real authentication data and generate fake data
+ * of the same length.
+ */
+ x11_saved_data = xmalloc(data_len);
+ x11_fake_data = xmalloc(data_len);
+ for (i = 0; i < data_len; i++) {
+ if (sscanf(data + 2 * i, "%2x", &value) != 1)
+ fatal("x11_request_forwarding: bad "
+ "authentication data: %.100s", data);
+ if (i % 4 == 0)
+ rnd = arc4random();
+ x11_saved_data[i] = value;
+ x11_fake_data[i] = rnd & 0xff;
+ rnd >>= 8;
+ }
+ x11_saved_data_len = data_len;
+ x11_fake_data_len = data_len;
}
- x11_saved_data_len = data_len;
- x11_fake_data_len = data_len;
/* Convert the fake data into hex. */
- len = 2 * data_len + 1;
- new_data = xmalloc(len);
- for (i = 0; i < data_len; i++)
- snprintf(new_data + 2 * i, len - 2 * i,
- "%02x", (u_char) x11_fake_data[i]);
+ new_data = tohex(x11_fake_data, data_len);
/* Send the request packet. */
if (compat20) {