- (djm) OpenBSD CVS Sync
- djm@cvs.openbsd.org 2005/06/16 03:38:36
[channels.c channels.h clientloop.c clientloop.h ssh.c]
move x11_get_proto from ssh.c to clientloop.c, to make muliplexed xfwd
easier later; ok deraadt@
diff --git a/clientloop.c b/clientloop.c
index ae4dce8..ee36cc9 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -59,7 +59,7 @@
*/
#include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.137 2005/06/08 11:25:09 djm Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.138 2005/06/16 03:38:36 djm Exp $");
#include "ssh.h"
#include "ssh1.h"
@@ -208,6 +208,109 @@
return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
}
+#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
+void
+client_x11_get_proto(const char *display, const char *xauth_path,
+ u_int trusted, char **_proto, char **_data)
+{
+ char cmd[1024];
+ char line[512];
+ char xdisplay[512];
+ static char proto[512], data[512];
+ FILE *f;
+ int got_data = 0, generated = 0, do_unlink = 0, i;
+ char *xauthdir, *xauthfile;
+ struct stat st;
+
+ xauthdir = xauthfile = NULL;
+ *_proto = proto;
+ *_data = data;
+ proto[0] = data[0] = '\0';
+
+ if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
+ debug("No xauth program.");
+ } else {
+ if (display == NULL) {
+ debug("x11_get_proto: DISPLAY not set");
+ return;
+ }
+ /*
+ * Handle FamilyLocal case where $DISPLAY does
+ * not match an authorization entry. For this we
+ * just try "xauth list unix:displaynum.screennum".
+ * XXX: "localhost" match to determine FamilyLocal
+ * is not perfect.
+ */
+ if (strncmp(display, "localhost:", 10) == 0) {
+ snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
+ display + 10);
+ display = xdisplay;
+ }
+ if (trusted == 0) {
+ xauthdir = xmalloc(MAXPATHLEN);
+ xauthfile = xmalloc(MAXPATHLEN);
+ strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
+ if (mkdtemp(xauthdir) != NULL) {
+ do_unlink = 1;
+ snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
+ xauthdir);
+ snprintf(cmd, sizeof(cmd),
+ "%s -f %s generate %s " SSH_X11_PROTO
+ " untrusted timeout 1200 2>" _PATH_DEVNULL,
+ xauth_path, xauthfile, display);
+ debug2("x11_get_proto: %s", cmd);
+ if (system(cmd) == 0)
+ generated = 1;
+ }
+ }
+ snprintf(cmd, sizeof(cmd),
+ "%s %s%s list %s . 2>" _PATH_DEVNULL,
+ xauth_path,
+ generated ? "-f " : "" ,
+ generated ? xauthfile : "",
+ display);
+ debug2("x11_get_proto: %s", cmd);
+ f = popen(cmd, "r");
+ if (f && fgets(line, sizeof(line), f) &&
+ sscanf(line, "%*s %511s %511s", proto, data) == 2)
+ got_data = 1;
+ if (f)
+ pclose(f);
+ }
+
+ if (do_unlink) {
+ unlink(xauthfile);
+ rmdir(xauthdir);
+ }
+ if (xauthdir)
+ xfree(xauthdir);
+ if (xauthfile)
+ xfree(xauthfile);
+
+ /*
+ * If we didn't get authentication data, just make up some
+ * data. The forwarding code will check the validity of the
+ * response anyway, and substitute this data. The X11
+ * server, however, will ignore this fake data and use
+ * whatever authentication mechanisms it was using otherwise
+ * for the local connection.
+ */
+ if (!got_data) {
+ u_int32_t rnd = 0;
+
+ logit("Warning: No xauth data; "
+ "using fake authentication data for X11 forwarding.");
+ strlcpy(proto, SSH_X11_PROTO, sizeof proto);
+ for (i = 0; i < 16; i++) {
+ if (i % 4 == 0)
+ rnd = arc4random();
+ snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
+ rnd & 0xff);
+ rnd >>= 8;
+ }
+ }
+}
+
/*
* This is called when the interactive is entered. This checks if there is
* an EOF coming on stdin. We must check this explicitly, as select() does