Improvements to -unixpw_cmd and -unixpw_nis.

Experimental X11VNC_WATCH_DX_DY=1 for buggy theme menus,
see: http://ubuntuforums.org/showthread.php?t=1223490

x11vnc/connections.c

@@ -574,18 +574,57 @@ int run_user_command(char *cmd, rfbClientPtr client, char *mode, char *input,
 	close_exec_fds();
 
 	if (output != NULL) {
-		FILE *ph = popen(cmd, "r");
+		FILE *ph;
 		char line[1024];
+		char *cmd2 = NULL;
+		char tmp[] = "/tmp/x11vnc-tmp.XXXXXX";
+		int deltmp = 0;
+
+		if (input != NULL) {
+			int tmp_fd = mkstemp(tmp);
+			if (tmp_fd < 0) {
+				rfbLog("mkstemp failed on: %s\n", tmp);
+				clean_up_exit(1);
+			}
+			write(tmp_fd, input, len);
+			close(tmp_fd);
+			deltmp = 1;
+			cmd2 = (char *) malloc(100 + strlen(tmp) + strlen(cmd));
+			sprintf(cmd2, "/bin/cat %s | %s", tmp, cmd);
+			
+			ph = popen(cmd2, "r");
+		} else {
+			ph = popen(cmd, "r");
+		}
 		if (ph == NULL) {
 			rfbLog("popen(%s) failed", cmd);
 			rfbLogPerror("popen");
 			clean_up_exit(1);
 		}
-		while (fgets(line, 1024, ph) != NULL) {
+		memset(line, 0, sizeof(line));
+		while (fgets(line, sizeof(line), ph) != NULL) {
+			int j, k = -1;
 			if (0) fprintf(stderr, "line: %s", line);
-			fprintf(output, "%s", line);
+			/* take care to handle embedded nulls */
+			for (j=0; j < sizeof(line); j++) {
+				if (line[j] != '\0') {
+					k = j;
+				}
+			}
+			if (k >= 0) {
+				write(fileno(output), line, k+1);
+			}
+			memset(line, 0, sizeof(line));
 		}
+
 		rc = pclose(ph);
+
+		if (cmd2 != NULL) {
+			free(cmd2);
+		}
+		if (deltmp) {
+			unlink(tmp);
+		}
 		goto got_rc;
 	} else if (input != NULL) {
 		FILE *ph = popen(cmd, "w");
@@ -789,7 +828,7 @@ void client_gone(rfbClientPtr client) {
 			free(userhost);
 		} else {
 			rfbLog("client_gone: using cmd: %s\n", client->host);
-			run_user_command(gone_cmd, client, "gone", NULL,0,NULL);
+			run_user_command(gone_cmd, client, "gone", NULL, 0, NULL);
 		}
 	}
 

x11vnc/enc.h

@@ -83,8 +83,8 @@ so, delete this exception statement from your version.
  *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
  *  USA  or see <http://www.gnu.org/licenses/>.
  *
- *  In addition, as a special exception, Karl J. Runge
+ *  In addition, as a special exception, Karl J. Runge gives permission
- *  gives permission to link the code of its release of x11vnc with the
+ *  to link the code of its release of ultravnc_dsm_helper with the
  *  OpenSSL project's "OpenSSL" library (or with modified versions of it
  *  that use the same license as the "OpenSSL" library), and distribute
  *  the linked executables.  You must obey the GNU General Public License

x11vnc/help.c

@@ -335,8 +335,8 @@ void print_help(int mode) {
 "                       is needed for the latter, feel free to ask).\n"
 "\n"
 "-scale fraction        Scale the framebuffer by factor \"fraction\".  Values\n"
-"                       less than 1 shrink the fb, larger ones expand it.  Note:\n"
+"                       less than 1 shrink the fb, larger ones expand it. Note:\n"
-"                       image may not be sharp and response may be slower.\n"
+"                       the image may not be sharp and response may be slower.\n"
 "                       If \"fraction\" contains a decimal point \".\" it\n"
 "                       is taken as a floating point number, alternatively\n"
 "                       the notation \"m/n\" may be used to denote fractions\n"
@@ -507,7 +507,7 @@ void print_help(int mode) {
 "                       Repeater mode: Some services provide an intermediate\n"
 "                       \"vnc repeater\": http://www.uvnc.com/addons/repeater.html\n"
 "                       (and also http://koti.mbnet.fi/jtko/ for linux port)\n"
-"                       that acts as a proxy / gateway.  Modes like these require\n"
+"                       that acts as a proxy/gateway.  Modes like these require\n"
 "                       an initial string to be sent for the reverse connection\n"
 "                       before the VNC protocol is started.  Here are the ways\n"
 "                       to do this:\n"
@@ -782,12 +782,12 @@ void print_help(int mode) {
 "                       full-access passwords)\n"
 "\n"
 "-unixpw [list]         Use Unix username and password authentication.  x11vnc\n"
-"                       uses the su(1) program to verify the user's password.\n"
+"                       will use the su(1) program to verify the user's\n"
-"                       [list] is an optional comma separated list of allowed\n"
+"                       password.  [list] is an optional comma separated list\n"
-"                       Unix usernames.  If the [list] string begins with the\n"
+"                       of allowed Unix usernames.  If the [list] string begins\n"
-"                       character \"!\" then the entire list is taken as an\n"
+"                       with the character \"!\" then the entire list is taken\n"
-"                       exclude list.  See below for per-user options that can\n"
+"                       as an exclude list.  See below for per-user options\n"
-"                       be applied.\n"
+"                       that can be applied.\n"
 "\n"
 "                       A familiar \"login:\" and \"Password:\" dialog is\n"
 "                       presented to the user on a black screen inside the\n"
@@ -803,8 +803,9 @@ void print_help(int mode) {
 "\n"
 "                       Since the detailed behavior of su(1) can vary from\n"
 "                       OS to OS and for local configurations, test the mode\n"
-"                       carefully.  x11vnc will attempt to be conservative and\n"
+"                       before deployment to make sure it is working properly.\n"
-"                       reject a login if anything abnormal occurs.\n"
+"                       x11vnc will attempt to be conservative and reject a\n"
+"                       login if anything abnormal occurs.\n"
 "\n"
 "                       One case to note: FreeBSD and the other BSD's by\n"
 "                       default it is impossible for the user running x11vnc to\n"
@@ -837,7 +838,7 @@ void print_help(int mode) {
 "                       to come from the same machine x11vnc is running on\n"
 "                       (e.g. from a ssh -L port redirection).  And that the\n"
 "                       -stunnel SSL mode be used for encryption over the\n"
-"                       network.(see the description of -stunnel below).\n"
+"                       network. (see the description of -stunnel below).\n"
 "\n"
 "                       Note: as a convenience, if you ssh(1) in and start\n"
 "                       x11vnc it will check if the environment variable\n"
@@ -865,7 +866,7 @@ void print_help(int mode) {
 "                       Set UNIXPW_DISABLE_LOCALHOST=1 to disable the -localhost\n"
 "                       requirement in Method 2).  One should never do this\n"
 "                       (i.e. allow the Unix passwords to be sniffed on the\n"
-"                       network).\n"
+"                       network.)\n"
 "\n"
 "                       Regarding reverse connections (e.g. -R connect:host\n"
 "                       and -connect host), when the -localhost constraint is\n"
@@ -883,7 +884,7 @@ void print_help(int mode) {
 "                       in -inetd mode (thereby bypassing inetd).  See the FAQ\n"
 "                       for details.\n"
 "\n"
-"                       The user names in the comma separated [list] can have\n"
+"                       The user names in the comma separated [list] may have\n"
 "                       per-user options after a \":\", e.g. \"fred:opts\"\n"
 "                       where \"opts\" is a \"+\" separated list of\n"
 "                       \"viewonly\", \"fullaccess\", \"input=XXXX\", or\n"
@@ -891,13 +892,13 @@ void print_help(int mode) {
 "                       For \"input=\" it is the K,M,B,C described under -input.\n"
 "\n"
 "                       If an item in the list is \"*\" that means those\n"
-"                       options apply to all users.  It also means all users\n"
+"                       options apply to all users.  It ALSO implies all users\n"
 "                       are allowed to log in after supplying a valid password.\n"
 "                       Use \"deny\" to explicitly deny some users if you use\n"
-"                       \"*\" to set a global option.  If [list] begins with\n"
+"                       \"*\" to set a global option.  If [list] begins with the\n"
-"                       the \"!\" character then \"*\" is ignored for checking\n"
+"                       \"!\" character then \"*\" is ignored for checking if\n"
-"                       if the user is allowed, but the any value of options\n"
+"                       the user is allowed, but the option values associated\n"
-"                       associated with it does apply as normal.\n"
+"                       with it do apply as normal.\n"
 "\n"
 "                       There are also some utilities for testing password\n"
 "                       if [list] starts with the \"%%\" character.  See the\n"
@@ -922,32 +923,89 @@ void print_help(int mode) {
 "\n"
 "                       NIS is not required for this mode to work (only that\n"
 "                       getpwnam(3) return the encrypted password is required),\n"
-"                       but it is unlikely it will work for any most modern\n"
+"                       but it is unlikely it will work (as an ordinary user)\n"
-"                       environments unless x11vnc is run as root to be able\n"
+"                       for most modern environments unless NIS is available.\n"
-"                       to access /etc/shadow (note running as root is often\n"
+"                       On the other hand, when x11vnc is run as root it will\n"
-"                       done when running x11vnc from inetd and xdm/gdm/kdm).\n"
+"                       be able to to access /etc/shadow even if NIS is not\n"
+"                       available (note running as root is often done when\n"
+"                       running x11vnc from inetd and xdm/gdm/kdm).\n"
 "\n"
 "                       Looked at another way, if you do not want to use the\n"
-"                       su(1) method provided by -unixpw, you can run x11vnc\n"
+"                       su(1) method provided by -unixpw (i.e. su_verify()), you\n"
-"                       as root and use -unixpw_nis.  Any users with passwords\n"
+"                       can run x11vnc as root and use -unixpw_nis.  Any users\n"
-"                       in /etc/shadow can then be authenticated.  You may want\n"
+"                       with passwords in /etc/shadow can then be authenticated.\n"
-"                       to use -users unixpw= to switch the process user after\n"
+"\n"
-"                       the user logs in.\n"
+"                       In -unixpw_nis mode, under no circumstances is x11vnc's\n"
+"                       user password verifying function based on su called\n"
+"                       (i.e. the function su_verify() that runs /bin/su\n"
+"                       in a pseudoterminal to verify passwords.)  However,\n"
+"                       if -unixpw_nis is used in conjunction with the -find\n"
+"                       and -create -display WAIT:... modes then, if x11vnc is\n"
+"                       running as root, /bin/su may be called externally to\n"
+"                       run the find or create commands.\n"
 "\n"
 "-unixpw_cmd cmd        As -unixpw above, however do not use su(1) but rather\n"
 "                       run the externally supplied command \"cmd\".  The first\n"
-"                       line of its stdin will the username and the second line\n"
+"                       line of its stdin will be the username and the second\n"
-"                       the received password.  If the command exits with status\n"
+"                       line the received password.  If the command exits\n"
-"                       0 (success) the VNC client will be accepted.  It will be\n"
+"                       with status 0 (success) the VNC user will be accepted.\n"
-"                       rejected for any other return status.\n"
+"                       It will be rejected for any other return status.\n"
-"\n"
+"\n"
-"                       Dynamic passwords and non-unix passwords can be\n"
+"                       Dynamic passwords and non-unix passwords, e.g. LDAP,\n"
-"                       implemented this way by providing your own custom helper\n"
+"                       can be implemented this way by providing your own custom\n"
-"                       program.  Note that under unixpw mode the remote viewer\n"
+"                       helper program.  Note that the remote viewer is given 3\n"
-"                       is given 3 tries to enter the correct password.\n"
+"                       tries to enter the correct password, and so the program\n"
-"\n"
+"                       may be called in a row that many (or more) times.\n"
-"                       If a list of allowed users is needed use -unixpw [list]\n"
+"\n"
-"                       in addition to this option.\n"
+"                       If a list of allowed users is needed to limit who can\n"
+"                       log in, use -unixpw [list] in addition to this option.\n"
+"\n"
+"                       In FINDDISPLAY and FINDCREATEDISPLAY modes the \"cmd\"\n"
+"                       will also be run with the RFB_UNIXPW_CMD_RUN env. var.\n"
+"                       non-empty and set to the corresponding display\n"
+"                       find/create command.  The first two lines of input are\n"
+"                       the username and passwd as in the normal case described\n"
+"                       above.  To support FINDDISPLAY and FINDCREATEDISPLAY,\n"
+"                       \"cmd\" should run the requested command as the user\n"
+"                       (and most likely refusing to run it if the password is\n"
+"                       not correct.)  Here is an example script (note it has\n"
+"                       a hardwired bogus password \"abc\"!)\n"
+"\n"
+"                         #!/bin/sh\n"
+"                         # Example x11vnc -unixpw_cmd script.\n"
+"                         # Read the first two lines of stdin (user and passwd)\n"
+"                         read user\n"
+"                         read pass\n"
+"                         \n"
+"                         debug=0\n"
+"                         if [ $debug = 1 ]; then\n"
+"                         	echo \"user: $user\" 1>&2\n"
+"                         	echo \"pass: $pass\" 1>&2\n"
+"                         	env | egrep -i 'rfb|vnc' 1>&2\n"
+"                         fi\n"
+"                         \n"
+"                         # Check if the password is valid.\n"
+"                         # (A real example would use ldap lookup, etc!)\n"
+"                         if [ \"X$pass\" != \"Xabc\" ]; then\n"
+"                         	exit 1	# incorrect password\n"
+"                         fi\n"
+"                         \n"
+"                         if [ \"X$RFB_UNIXPW_CMD_RUN\" = \"X\" ]; then\n"
+"                         	exit 0	# correct password\n"
+"                         else\n"
+"                         	# Run the requested command (finddisplay)\n"
+"                         	if [ $debug = 1 ]; then\n"
+"                         		echo \"run: $RFB_UNIXPW_CMD_RUN\" 1>&2\n"
+"                         	fi\n"
+"                         	exec /bin/su - \"$user\" -c \"$RFB_UNIXPW_CMD_RUN\"\n"
+"                         fi\n"
+"\n"
+"                       In -unixpw_cmd mode, under no circumstances is x11vnc's\n"
+"                       user password verifying function based on su called\n"
+"                       (i.e. the function su_verify() that runs /bin/su in a\n"
+"                       pseudoterminal to verify passwords.)  It is up to the\n"
+"                       supplied unixpw_cmd to do user switching if desired\n"
+"                       and if it has the permissions to do so.\n"
 "\n"
 "-find                  Find the user's display using FINDDISPLAY. This is an\n"
 "                       alias for \"-display WAIT:cmd=FINDDISPLAY\".\n"
@@ -1064,9 +1122,15 @@ void print_help(int mode) {
 "\n"
 "                            xauth extract - $DISPLAY\"\n"
 "\n"
-"                       In the case of -unixpw (but not -unixpw_nis), then the\n"
+"                       In the case of -unixpw (and -unixpw_nis only if x11vnc\n"
-"                       cmd= command is run as the user who just authenticated\n"
+"                       is running as root), then the cmd= command is run\n"
-"                       via the login and password prompt.\n"
+"                       as the user who just authenticated via the login and\n"
+"                       password prompt.\n"
+"\n"
+"                       In the case of -unixpw_cmd, the commands will also be\n"
+"                       run as the logged-in user, as long as the user-supplied\n"
+"                       helper program supports RFB_UNIXPW_CMD_RUN (see the\n"
+"                       -unixpw_cmd option.)\n"
 "\n"
 "                       Also in the case of -unixpw, the user logging in can\n"
 "                       place a colon at the end of her username and supply\n"

x11vnc/pointer.c

@@ -343,11 +343,22 @@ void update_x11_pointer_position(int x, int y) {
 	return;
 #else
 	int rc;
+	static int watch_dx_dy = -1;
 
 	RAWFB_RET_VOID
 
+	if (watch_dx_dy == -1) {
+		if (getenv("X11VNC_WATCH_DX_DY")) {
+			watch_dx_dy = 1;
+		} else {
+			watch_dx_dy = 0;
+		}
+	}
+
 	X_LOCK;
-	if (use_xwarppointer) {
+	if (watch_dx_dy && cursor_x == x && cursor_y == y) {
+		;
+	} else if (use_xwarppointer) {
 		/*
 		 * off_x and off_y not needed with XWarpPointer since
 		 * window is used:

x11vnc/unixpw.c

@@ -96,6 +96,7 @@ void unixpw_accept(char *user);
 void unixpw_deny(void);
 void unixpw_msg(char *msg, int delay);
 int su_verify(char *user, char *pass, char *cmd, char *rbuf, int *rbuf_size, int nodisp);
+int unixpw_cmd_run(char *user, char *pass, char *cmd, char *line, int *n, int nodisp);
 int crypt_verify(char *user, char *pass);
 int cmd_verify(char *user, char *pass);
 void unixpw_verify_screen(char *user, char *pass);
@@ -530,6 +531,82 @@ int crypt_verify(char *user, char *pass) {
 #endif	/* UNIXPW_CRYPT */
 }
 
+int unixpw_cmd_run(char *user, char *pass, char *cmd, char *line, int *n, int nodisp) {
+	int i, len, rc;
+	char *str;
+	FILE *out;
+
+	if (! user || ! pass) {
+		return 0;
+	}
+	if (! unixpw_cmd || *unixpw_cmd == '\0') {
+		return 0;
+	}
+
+	if (! scheck(user, 100, "username")) {
+		return 0;
+	}
+	if (! scheck(pass, 100, "password")) {
+		return 0;
+	}
+	if (! unixpw_list_match(user)) {
+		return 0;
+	}
+	if (cmd == NULL) {
+		cmd = "";
+	}
+
+	len = strlen(user) + 1 + strlen(pass) + 1 + 1;
+	str = (char *) malloc(len);
+	if (! str) {
+		return 0;
+	}
+	str[0] = '\0';
+	strcat(str, user);
+	strcat(str, "\n");
+	strcat(str, pass);
+	if (!strchr(pass, '\n')) {
+		strcat(str, "\n");
+	}
+
+	out = tmpfile();
+	if (out == NULL) {
+		rfbLog("unixpw_cmd_run tmpfile() failed.\n");
+		clean_up_exit(1);
+	}
+
+	set_env("RFB_UNIXPW_CMD_RUN", cmd);
+
+	rc = run_user_command(unixpw_cmd, unixpw_client, "cmd_verify",
+	    str, strlen(str), out);
+
+	set_env("RFB_UNIXPW_CMD_RUN", "");
+
+	for (i=0; i < len; i++) {
+		str[i] = '\0';
+	}
+	free(str);
+
+	fflush(out);
+	rewind(out);
+	for (i=0; i < (*n) - 1; i++) {
+		int c = fgetc(out);
+		if (c == EOF) {
+			break;
+		}
+		line[i] = (char) c;
+	}
+	fclose(out);
+	*n = i;
+
+	if (rc == 0) {
+		return 1;
+	} else {
+		return 0;
+	}
+}
+
+
 int cmd_verify(char *user, char *pass) {
 	int i, len, rc;
 	char *str;
@@ -602,6 +679,7 @@ int su_verify(char *user, char *pass, char *cmd, char *rbuf, int *rbuf_size, int
 		set_db();
 		first = 0;
 	}
+	rfbLog("su_verify: '%s' for %s.\n", user, cmd ? "command" : "login");
 
 	if (! scheck(user, 100, "username")) {
 		return 0;
@@ -1043,7 +1121,7 @@ int unixpw_verify(char *user, char *pass) {
 			    " succeeded.\n", user);
 			ok = 1;
 		} else {
-			rfbLog("unixpw_verify: crypt_verify login for '%s'"
+			rfbLog("unixpw_verify: cmd_verify login for '%s'"
 			    " failed.\n", user);
 			usleep(3000*1000);
 			ok = 0;

x11vnc/unixpw.h

@@ -42,6 +42,7 @@ extern void unixpw_accept(char *user);
 extern void unixpw_deny(void);
 extern void unixpw_msg(char *msg, int delay);
 extern int su_verify(char *user, char *pass, char *cmd, char *rbuf, int *rbuf_size, int nodisp);
+extern int unixpw_cmd_run(char *user, char *pass, char *cmd, char *line, int *n, int nodisp);
 extern int crypt_verify(char *user, char *pass);
 extern int cmd_verify(char *user, char *pass);
 extern int unixpw_verify(char *user, char *pass);

x11vnc/user.c

@@ -308,6 +308,9 @@ static void user2uid(char *user, uid_t *uid, gid_t *gid, char **name, char **hom
 			if (strstr(user2group[i], user) == user2group[i]) {
 				char *w = user2group[i] + strlen(user);
 				if (*w == '.') {
+#if (SMALL_FOOTPRINT > 2)
+					gotgroup = 0;
+#else
 					struct group* gr = getgrnam(++w);
 					if (! gr) {
 						rfbLog("Invalid group: %s\n", w);
@@ -320,6 +323,7 @@ static void user2uid(char *user, uid_t *uid, gid_t *gid, char **name, char **hom
 						did[i] = 1;
 					}
 					gotgroup = 1;
+#endif
 				}
 			}
 			i++;
@@ -761,7 +765,7 @@ static int switch_user_env(uid_t uid, gid_t gid, char *name, char *home, int fb_
 	return 0;
 #else
 	/*
-	 * OK tricky here, we need to free the shm... otherwise
+	 * OK, tricky here, we need to free the shm... otherwise
 	 * we won't be able to delete it as the other user...
 	 */
 	if (fb_mode == 1 && (using_shm && ! xform24to32)) {
@@ -773,11 +777,13 @@ static int switch_user_env(uid_t uid, gid_t gid, char *name, char *home, int fb_
 #if LIBVNCSERVER_HAVE_PWD_H
 	if (getpwuid(uid) != NULL && getenv("X11VNC_SINGLE_GROUP") == NULL) {
 		struct passwd *p = getpwuid(uid);
-		if (initgroups(p->pw_name, gid) == 0)  {
+		/* another possibility is p->pw_gid instead of gid */
+		if (setgid(gid) == 0 && initgroups(p->pw_name, gid) == 0)  {
 			grp_ok = 1;
 		} else {
 			rfbLogPerror("initgroups");
 		}
+		endgrent();
 	}
 #endif
 #endif
@@ -2235,12 +2241,58 @@ static char *get_usslpeer() {
 	return upeer;
 }
 
+static void do_try_switch(char *usslpeer, char *users_list_save) {
+	if (usslpeer) {
+		char *u = (char *) malloc(strlen(usslpeer+2));
+		sprintf(u, "+%s", usslpeer);
+		if (switch_user(u, 0)) {
+			rfbLog("sslpeer switched to user: %s\n", usslpeer);
+		} else {
+			rfbLog("sslpeer failed to switch to user: %s\n", usslpeer);
+		}
+		free(u);
+		
+	} else if (users_list_save && keep_unixpw_user) {
+		char *user = keep_unixpw_user;
+		char *u = (char *)malloc(strlen(user)+1); 
+
+		users_list = users_list_save;
+
+		u[0] = '\0';
+		if (!strcmp(users_list, "unixpw=")) {
+			sprintf(u, "+%s", user);
+		} else {
+			char *p, *str = strdup(users_list);
+			p = strtok(str + strlen("unixpw="), ",");
+			while (p) {
+				if (!strcmp(p, user)) {
+					sprintf(u, "+%s", user);
+					break;
+				}
+				p = strtok(NULL, ",");
+			}
+			free(str);
+		}
+		
+		if (u[0] == '\0') {
+			rfbLog("unixpw_accept skipping switch to user: %s (drc)\n", user);
+		} else if (switch_user(u, 0)) {
+			rfbLog("unixpw_accept switched to user: %s (drc)\n", user);
+		} else {
+			rfbLog("unixpw_accept failed to switch to user: %s (drc)\n", user);
+		}
+		free(u);
+	}
+}
+
 static int do_run_cmd(char *cmd, char *create_cmd, char *users_list_save, int created_disp, int db) {
 	char tmp[] = "/tmp/x11vnc-find_display.XXXXXX";
 	char line1[1024], line2[16384];
 	char *q, *usslpeer = NULL;
 	int n, nodisp = 0, saw_xdmcp = 0;
 	int tmp_fd = -1;
+	int internal_cmd = 0;
+	int tried_switch = 0;
 
 	memset(line1, 0, 1024);
 	memset(line2, 0, 16384);
@@ -2251,6 +2303,7 @@ static int do_run_cmd(char *cmd, char *create_cmd, char *users_list_save, int cr
 			return 0;
 		}
 	}
+	if (getenv("DEBUG_RUN_CMD")) db = 1;
 
 	/* only sets environment variables: */
 	run_user_command("", latest_client, "env", NULL, 0, NULL);
@@ -2265,7 +2318,11 @@ static int do_run_cmd(char *cmd, char *create_cmd, char *users_list_save, int cr
 	    strstr(cmd, "FINDCREATEDISPLAY") == cmd) {
 		char *nd = "";
 		char fdout[128];
+
+		internal_cmd = 1;
+
 		tmp_fd = mkstemp(tmp);
+
 		if (tmp_fd < 0) {
 			rfbLog("wait_for_client: open failed: %s\n", tmp);
 			rfbLogPerror("mkstemp");
@@ -2302,7 +2359,7 @@ static int do_run_cmd(char *cmd, char *create_cmd, char *users_list_save, int cr
 
 	rfbLog("wait_for_client: running: %s\n", cmd);
 
-	if (unixpw) {
+	if (unixpw && !unixpw_nis) {
 		int res = 0, k, j, i;
 		char line[18000];
 
@@ -2310,8 +2367,13 @@ static int do_run_cmd(char *cmd, char *create_cmd, char *users_list_save, int cr
 
 		if (keep_unixpw_user && keep_unixpw_pass) {
 			n = 18000;
-			res = su_verify(keep_unixpw_user,
+			if (unixpw_cmd != NULL) {
-			    keep_unixpw_pass, cmd, line, &n, nodisp);
+				res = unixpw_cmd_run(keep_unixpw_user,
+				    keep_unixpw_pass, cmd, line, &n, nodisp);
+			} else {
+				res = su_verify(keep_unixpw_user,
+				    keep_unixpw_pass, cmd, line, &n, nodisp);
+			}
 		}
 
 if (db) {fprintf(stderr, "line: "); write(2, line, n); write(2, "\n", 1); fprintf(stderr, "res=%d n=%d\n", res, n);}
@@ -2331,7 +2393,13 @@ if (db) {fprintf(stderr, "line: "); write(2, line, n); write(2, "\n", 1); fprint
 
 			findcreatedisplay = 1;
 
-			if (getuid() != 0) {
+			if (unixpw_cmd != NULL) {
+				/* let the external unixpw command do it: */
+				n = 18000;
+				close_exec_fds();
+				res = unixpw_cmd_run(keep_unixpw_user,
+				    keep_unixpw_pass, create_cmd, line, &n, nodisp);
+			} else if (getuid() != 0) {
 				/* if not root, run as the other user... */
 				n = 18000;
 				close_exec_fds();
@@ -2411,6 +2479,7 @@ if (db) fprintf(stderr, "line1: '%s'\n", line1);
 		}
 if (db) write(2, line, 100);
 if (db) fprintf(stderr, "\n");
+
 	} else {
 		FILE *p;
 		int rc;
@@ -2428,9 +2497,22 @@ if (db) fprintf(stderr, "\n");
 			p = popen(c, "r");
 			free(c);
 			
+		} else if (unixpw_nis && keep_unixpw_user) {
+			char *c;
+			if (getuid() == 0) {
+				c = (char *) malloc(strlen("su - '' -c \"")
+				    + strlen(keep_unixpw_user) + strlen(cmd) + 1 + 1);
+				sprintf(c, "su - '%s' -c \"%s\"", keep_unixpw_user, cmd);
+			} else {
+				c = strdup(cmd);
+			}
+			p = popen(c, "r");
+			free(c);
+			
 		} else {
 			p = popen(cmd, "r");
 		}
+
 		if (! p) {
 			rfbLog("wait_for_client: cmd failed: %s\n", cmd);
 			rfbLogPerror("popen");
@@ -2575,49 +2657,13 @@ fprintf(stderr, "\n");}
 		}
 	}
 
-	if (usslpeer) {
+	if (!tried_switch) {
-		char *u = (char *) malloc(strlen(usslpeer+2));
+		do_try_switch(usslpeer, users_list_save);
-		sprintf(u, "+%s", usslpeer);
+		tried_switch = 1;
-		if (switch_user(u, 0)) {
-			rfbLog("sslpeer switched to user: %s\n", usslpeer);
-		} else {
-			rfbLog("sslpeer failed to switch to user: %s\n", usslpeer);
-		}
-		free(u);
-		
-	} else if (users_list_save && keep_unixpw_user) {
-		char *user = keep_unixpw_user;
-		char *u = (char *)malloc(strlen(user)+1); 
-
-		users_list = users_list_save;
-
-		u[0] = '\0';
-		if (!strcmp(users_list, "unixpw=")) {
-			sprintf(u, "+%s", user);
-		} else {
-			char *p, *str = strdup(users_list);
-			p = strtok(str + strlen("unixpw="), ",");
-			while (p) {
-				if (!strcmp(p, user)) {
-					sprintf(u, "+%s", user);
-					break;
-				}
-				p = strtok(NULL, ",");
-			}
-			free(str);
-		}
-		
-		if (u[0] == '\0') {
-			rfbLog("unixpw_accept skipping switch to user: %s\n", user);
-		} else if (switch_user(u, 0)) {
-			rfbLog("unixpw_accept switched to user: %s\n", user);
-		} else {
-			rfbLog("unixpw_accept failed to switch to user: %s\n", user);
-		}
-		free(u);
 	}
 
 	if (unixpw) {
+		/* Some cleanup and messaging for -unixpw case: */
 		char str[32];
 
 		if (keep_unixpw_user && keep_unixpw_pass) {

x11vnc/x11vnc.1

@@ -1,8 +1,8 @@
 .\" This file was automatically generated from x11vnc -help output.
-.TH X11VNC "1" "July 2009" "x11vnc " "User Commands"
+.TH X11VNC "1" "August 2009" "x11vnc " "User Commands"
 .SH NAME
 x11vnc - allow VNC connections to real X11 displays
-         version: 0.9.9, lastmod: 2009-07-11
+         version: 0.9.9, lastmod: 2009-08-10
 .SH SYNOPSIS
 .B x11vnc
 [OPTION]...
@@ -347,8 +347,8 @@ is needed for the latter, feel free to ask).
 \fB-scale\fR \fIfraction\fR
 .IP
 Scale the framebuffer by factor \fIfraction\fR.  Values
-less than 1 shrink the fb, larger ones expand it.  Note:
+less than 1 shrink the fb, larger ones expand it. Note:
-image may not be sharp and response may be slower.
+the image may not be sharp and response may be slower.
 If \fIfraction\fR contains a decimal point "." it
 is taken as a floating point number, alternatively
 the notation "m/n" may be used to denote fractions
@@ -568,7 +568,7 @@ is running as root (e.g. via
 Repeater mode: Some services provide an intermediate
 "vnc repeater": http://www.uvnc.com/addons/repeater.html
 (and also http://koti.mbnet.fi/jtko/ for linux port)
-that acts as a proxy / gateway.  Modes like these require
+that acts as a proxy/gateway.  Modes like these require
 an initial string to be sent for the reverse connection
 before the VNC protocol is started.  Here are the ways
 to do this:
@@ -871,14 +871,14 @@ full-access passwords)
 \fB-unixpw\fR \fI[list]\fR
 .IP
 Use Unix username and password authentication.  x11vnc
-uses the 
+will use the 
 .IR su (1)
-program to verify the user's password.
+program to verify the user's
-[list] is an optional comma separated list of allowed
+password.  [list] is an optional comma separated list
-Unix usernames.  If the [list] string begins with the
+of allowed Unix usernames.  If the [list] string begins
-character "!" then the entire list is taken as an
+with the character "!" then the entire list is taken
-exclude list.  See below for per-user options that can
+as an exclude list.  See below for per-user options
-be applied.
+that can be applied.
 .IP
 A familiar "login:" and "Password:" dialog is
 presented to the user on a black screen inside the
@@ -896,8 +896,9 @@ Since the detailed behavior of
 .IR su (1)
 can vary from
 OS to OS and for local configurations, test the mode
-carefully.  x11vnc will attempt to be conservative and
+before deployment to make sure it is working properly.
-reject a login if anything abnormal occurs.
+x11vnc will attempt to be conservative and reject a
+login if anything abnormal occurs.
 .IP
 One case to note: FreeBSD and the other BSD's by
 default it is impossible for the user running x11vnc to
@@ -932,7 +933,7 @@ Method 2) requires the viewer connection to appear
 to come from the same machine x11vnc is running on
 (e.g. from a ssh \fB-L\fR port redirection).  And that the
 \fB-stunnel\fR SSL mode be used for encryption over the
-network.(see the description of \fB-stunnel\fR below).
+network. (see the description of \fB-stunnel\fR below).
 .IP
 Note: as a convenience, if you 
 .IR ssh (1)
@@ -966,7 +967,7 @@ local connections from that machine are accepted).
 Set UNIXPW_DISABLE_LOCALHOST=1 to disable the \fB-localhost\fR
 requirement in Method 2).  One should never do this
 (i.e. allow the Unix passwords to be sniffed on the
-network).
+network.)
 .IP
 Regarding reverse connections (e.g. \fB-R\fR connect:host
 and \fB-connect\fR host), when the \fB-localhost\fR constraint is
@@ -984,7 +985,7 @@ Tip: you can also have your own stunnel spawn x11vnc
 in \fB-inetd\fR mode (thereby bypassing inetd).  See the FAQ
 for details.
 .IP
-The user names in the comma separated [list] can have
+The user names in the comma separated [list] may have
 per-user options after a ":", e.g. "fred:opts"
 where "opts" is a "+" separated list of
 "viewonly", "fullaccess", "input=XXXX", or
@@ -992,13 +993,13 @@ where "opts" is a "+" separated list of
 For "input=" it is the K,M,B,C described under \fB-input.\fR
 .IP
 If an item in the list is "*" that means those
-options apply to all users.  It also means all users
+options apply to all users.  It ALSO implies all users
 are allowed to log in after supplying a valid password.
 Use "deny" to explicitly deny some users if you use
-"*" to set a global option.  If [list] begins with
+"*" to set a global option.  If [list] begins with the
-the "!" character then "*" is ignored for checking
+"!" character then "*" is ignored for checking if
-if the user is allowed, but the any value of options
+the user is allowed, but the option values associated
-associated with it does apply as normal.
+with it do apply as normal.
 .IP
 There are also some utilities for testing password
 if [list] starts with the "%" character.  See the
@@ -1032,18 +1033,27 @@ user can authenticate ANY user.
 NIS is not required for this mode to work (only that
 .IR getpwnam (3)
 return the encrypted password is required),
-but it is unlikely it will work for any most modern
+but it is unlikely it will work (as an ordinary user)
-environments unless x11vnc is run as root to be able
+for most modern environments unless NIS is available.
-to access /etc/shadow (note running as root is often
+On the other hand, when x11vnc is run as root it will
-done when running x11vnc from inetd and xdm/gdm/kdm).
+be able to to access /etc/shadow even if NIS is not
+available (note running as root is often done when
+running x11vnc from inetd and xdm/gdm/kdm).
 .IP
 Looked at another way, if you do not want to use the
 .IR su (1)
-method provided by \fB-unixpw,\fR you can run x11vnc
+method provided by \fB-unixpw\fR (i.e. su_verify()), you
-as root and use \fB-unixpw_nis.\fR  Any users with passwords
+can run x11vnc as root and use \fB-unixpw_nis.\fR  Any users
-in /etc/shadow can then be authenticated.  You may want
+with passwords in /etc/shadow can then be authenticated.
-to use \fB-users\fR unixpw= to switch the process user after
+.IP
-the user logs in.
+In \fB-unixpw_nis\fR mode, under no circumstances is x11vnc's
+user password verifying function based on su called
+(i.e. the function su_verify() that runs /bin/su
+in a pseudoterminal to verify passwords.)  However,
+if \fB-unixpw_nis\fR is used in conjunction with the \fB-find\fR
+and \fB-create\fR \fB-display\fR WAIT:... modes then, if x11vnc is
+running as root, /bin/su may be called externally to
+run the find or create commands.
 .PP
 \fB-unixpw_cmd\fR \fIcmd\fR
 .IP
@@ -1051,18 +1061,66 @@ As \fB-unixpw\fR above, however do not use
 .IR su (1)
 but rather
 run the externally supplied command \fIcmd\fR.  The first
-line of its stdin will the username and the second line
+line of its stdin will be the username and the second
-the received password.  If the command exits with status
+line the received password.  If the command exits
-0 (success) the VNC client will be accepted.  It will be
+with status 0 (success) the VNC user will be accepted.
-rejected for any other return status.
+It will be rejected for any other return status.
-.IP
+.IP
-Dynamic passwords and non-unix passwords can be
+Dynamic passwords and non-unix passwords, e.g. LDAP,
-implemented this way by providing your own custom helper
+can be implemented this way by providing your own custom
-program.  Note that under unixpw mode the remote viewer
+helper program.  Note that the remote viewer is given 3
-is given 3 tries to enter the correct password.
+tries to enter the correct password, and so the program
-.IP
+may be called in a row that many (or more) times.
-If a list of allowed users is needed use \fB-unixpw\fR [list]
+.IP
-in addition to this option.
+If a list of allowed users is needed to limit who can
+log in, use \fB-unixpw\fR [list] in addition to this option.
+.IP
+In FINDDISPLAY and FINDCREATEDISPLAY modes the \fIcmd\fR
+will also be run with the RFB_UNIXPW_CMD_RUN env. var.
+non-empty and set to the corresponding display
+find/create command.  The first two lines of input are
+the username and passwd as in the normal case described
+above.  To support FINDDISPLAY and FINDCREATEDISPLAY,
+\fIcmd\fR should run the requested command as the user
+(and most likely refusing to run it if the password is
+not correct.)  Here is an example script (note it has
+a hardwired bogus password "abc"!)
+.IP
+#!/bin/sh
+# Example x11vnc \fB-unixpw_cmd\fR script.
+# Read the first two lines of stdin (user and passwd)
+read user
+read pass
+.IP
+debug=0
+if [ $debug = 1 ]; then
+echo "user: $user" 1>&2
+echo "pass: $pass" 1>&2
+env | egrep \fB-i\fR 'rfb|vnc' 1>&2
+fi
+.IP
+# Check if the password is valid.
+# (A real example would use ldap lookup, etc!)
+if [ "X$pass" != "Xabc" ]; then
+exit 1	# incorrect password
+fi
+.IP
+if [ "X$RFB_UNIXPW_CMD_RUN" = "X" ]; then
+exit 0	# correct password
+else
+# Run the requested command (finddisplay)
+if [ $debug = 1 ]; then
+echo "run: $RFB_UNIXPW_CMD_RUN" 1>&2
+fi
+exec /bin/su - "$user" \fB-c\fR "$RFB_UNIXPW_CMD_RUN"
+fi
+.IP
+In \fB-unixpw_cmd\fR mode, under no circumstances is x11vnc's
+user password verifying function based on su called
+(i.e. the function su_verify() that runs /bin/su in a
+pseudoterminal to verify passwords.)  It is up to the
+supplied unixpw_cmd to do user switching if desired
+and if it has the permissions to do so.
 .PP
 \fB-find\fR
 .IP
@@ -1214,9 +1272,15 @@ xauthority data for the display. For example;
 .IP
 xauth extract - $DISPLAY"
 .IP
-In the case of \fB-unixpw\fR (but not \fB-unixpw_nis),\fR then the
+In the case of \fB-unixpw\fR (and \fB-unixpw_nis\fR only if x11vnc
-cmd= command is run as the user who just authenticated
+is running as root), then the cmd= command is run
-via the login and password prompt.
+as the user who just authenticated via the login and
+password prompt.
+.IP
+In the case of \fB-unixpw_cmd,\fR the commands will also be
+run as the logged-in user, as long as the user-supplied
+helper program supports RFB_UNIXPW_CMD_RUN (see the
+\fB-unixpw_cmd\fR option.)
 .IP
 Also in the case of \fB-unixpw,\fR the user logging in can
 place a colon at the end of her username and supply
@@ -5827,7 +5891,7 @@ max time in ms to wait for RFB client
 \fB-rfbauth\fR \fIpasswd-file\fR
 .IP
 use authentication on RFB protocol
-(use 'storepasswd' to create a password file)
+(use 'x11vnc \fB-storepasswd\fR pass file' to create a password file)
 .PP
 \fB-rfbversion\fR \fI3.x\fR
 .IP

x11vnc/x11vnc.c

@@ -2482,6 +2482,9 @@ int main(int argc, char* argv[]) {
 			if (unixpw_list) {
 				unixpw_list = NULL;
 			}
+			if (unixpw_cmd) {
+				unixpw_cmd = NULL;
+			}
 			continue;
 		}
 		if (!strcmp(arg, "-vencrypt")) {

x11vnc/x11vnc_defs.c

@@ -47,7 +47,7 @@ int xtrap_base_event_type = 0;
 int xdamage_base_event_type = 0;
 
 /*               date +'lastmod: %Y-%m-%d' */
-char lastmod[] = "0.9.9 lastmod: 2009-07-11";
+char lastmod[] = "0.9.9 lastmod: 2009-08-10";
 
 /* X display info */