[Qemu-devel] [PATCH] Let user set vnc password from command line or file

[Qemu-devel] [PATCH] Let user set vnc password from command line or file

[Leandro Dardini]

Here is a little patch to let the user specify the vnc server password 
in the command line (yes, it is visible with the ps command) or via an 
external file (better choice). This adds two new arguments, 
-vnc-password and -vnc-password-file. The file containing the vnc 
password is in clear.

Please let me know if there is any writing rule I was not following, 
I'll be glad to modify the patch accordingly. I was doubtful whether to 
use a straight fopen or the QEMU_fopen. Let me know the difference.

Thank you

Leandro

diff -u -p vl.c.orig vl.c
--- vl.c.orig   2008-01-05 01:17:53.000000000 +0100
+++ vl.c        2008-01-06 12:17:11.000000000 +0100
@@ -7606,6 +7606,8 @@ static void help(int exitcode)
            "-no-reboot      exit instead of rebooting\n"
            "-loadvm file    start right away with a saved state (loadvm 
in monitor)\n"
           "-vnc display    start a VNC server on display\n"
+          "-vnc-password password    set VNC server password\n"
+          "-vnc-password-file file   set VNC server password (in clear) 
from file\n"
 #ifndef _WIN32
           "-daemonize      daemonize QEMU after initializing\n"
 #endif
@@ -7717,6 +7719,8 @@ enum {
     QEMU_OPTION_old_param,
     QEMU_OPTION_clock,
     QEMU_OPTION_startdate,
+    QEMU_OPTION_vnc_password,
+    QEMU_OPTION_vnc_password_file,
 };

 typedef struct QEMUOption {
@@ -7803,6 +7807,8 @@ const QEMUOption qemu_options[] = {
     { "usbdevice", HAS_ARG, QEMU_OPTION_usbdevice },
     { "smp", HAS_ARG, QEMU_OPTION_smp },
     { "vnc", HAS_ARG, QEMU_OPTION_vnc },
+    { "vnc-password", HAS_ARG, QEMU_OPTION_vnc_password },
+    { "vnc-password-file", HAS_ARG, QEMU_OPTION_vnc_password_file },

     /* temporary options */
     { "usb", 0, QEMU_OPTION_usb },
@@ -8085,6 +8091,9 @@ int main(int argc, char **argv)
     int fds[2];
     const char *pid_file = NULL;
     VLANState *vlan;
+    char vnc_password[9];
+    FILE *fd_vnc_password_file;
+    const char *vnc_password_file = NULL;

     LIST_INIT (&vm_change_state_head);
 #ifndef _WIN32
@@ -8580,6 +8589,13 @@ int main(int argc, char **argv)
            case QEMU_OPTION_vnc:
                vnc_display = optarg;
                break;
+           case QEMU_OPTION_vnc_password:
+               strncpy(vnc_password,optarg,8);
+               vnc_password[8] = '\0';
+                break;
+           case QEMU_OPTION_vnc_password_file:
+               vnc_password_file = optarg;
+               break;
             case QEMU_OPTION_no_acpi:
                 acpi_enabled = 0;
                 break;
@@ -8849,8 +8865,21 @@ int main(int argc, char **argv)
         dumb_display_init(ds);
     } else if (vnc_display != NULL) {
         vnc_display_init(ds);
+       if (vnc_password_file != NULL) {
+         fd_vnc_password_file = fopen(vnc_password_file, "r");
+         if (!fd_vnc_password_file) {
+           fprintf(stderr, "qemu: could not open vnc server password 
file '%s'\n", vnc_password_file);
+           exit(1);
+         }
+         fgets(vnc_password,9,fd_vnc_password_file);
+         if (vnc_password[strlen(vnc_password) - 1] == '\n')
+           vnc_password[strlen(vnc_password) - 1] = '\0';
+         fclose(fd_vnc_password_file);
+       }
+       if (vnc_password && vnc_password[0])
+         vnc_display_password(NULL,vnc_password);
         if (vnc_display_open(ds, vnc_display) < 0)
-            exit(1);
+         exit(1);
     } else {
 #if defined(CONFIG_SDL)
         sdl_display_init(ds, full_screen, no_frame);

Re: [Qemu-devel] [PATCH] Let user set vnc password from command line or file

[Daniel P. Berrange]

On Sun, Jan 06, 2008 at 11:45:58AM +0100, Leandro Dardini wrote:
> Here is a little patch to let the user specify the vnc server password 
> in the command line (yes, it is visible with the ps command) or via an 
> external file (better choice). This adds two new arguments, 
> -vnc-password and -vnc-password-file. The file containing the vnc 
> password is in clear.

Providing a password which is clearly visible on the command line to all
users of a machine is unacceptable.  This capability was *explicitly* left 
out when I did the original VNC password support in QEMU.

Providing a password via a file is reasonable, but this should be made
more general than just VNC. QCow2 disks files can be encrypted and require
passwords too. So I think it'd be more useful to have a '-passwd-file file'
arg, and in that file have 1 line per (device, password) pair. 

eg Assuming use of VNC, and 2 qcow encrypted disks one might have:

      vnc: 123456
      hda: mysecret
      hdb: othersecret

Perhaps 'hda' should be the more general syntax used by the -drive param
instead, or even the qcow file name...

Regards,
Dan.
-- 
|=- Red Hat, Engineering, Emerging Technologies, Boston.  +1 978 392 2496 -=|
|=-           Perl modules: http://search.cpan.org/~danberr/              -=|
|=-               Projects: http://freshmeat.net/~danielpb/               -=|
|=-  GnuPG: 7D3B9505   F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505  -=|