Re: [Qemu-devel] PATCH 7/8: command line args for x509 cert paths

[Daniel P. Berrange]

This final code patch adds 4 new command line arguments to QEMU to allow the
certificate files to be specified. The '-x509cacert', '-x509cert' and '-x509key'
parameters are mandatory if the 'x509' or 'x509verify' flags are used when
setting up the VNC server. If the certificates are not provided, all client
authentication attempts will be rejected.

diff -r f38519b13575 vl.c
--- a/vl.c      Tue Jul 31 14:51:31 2007 -0400
+++ b/vl.c      Tue Jul 31 14:51:32 2007 -0400
@@ -6701,6 +6701,12 @@ 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"
+#if CONFIG_VNC_TLS
+          "-x509cacert FILE  x509 CA certificate for TLS services\n"
+          "-x509cacrl FILE   x509 CA certificate revocation list for TLS 
services\n"
+          "-x509cert FILE    x509 public certificate for TLS services\n"
+          "-x509key FILE     x509 private key for TLS services\n"
+#endif
 #ifndef _WIN32
           "-daemonize      daemonize QEMU after initializing\n"
 #endif
@@ -6796,6 +6802,12 @@ enum {
     QEMU_OPTION_usbdevice,
     QEMU_OPTION_smp,
     QEMU_OPTION_vnc,
+#if CONFIG_VNC_TLS
+    QEMU_OPTION_x509cacert,
+    QEMU_OPTION_x509cacrl,
+    QEMU_OPTION_x509cert,
+    QEMU_OPTION_x509key,
+#endif
     QEMU_OPTION_no_acpi,
     QEMU_OPTION_no_reboot,
     QEMU_OPTION_show_cursor,
@@ -6889,6 +6901,12 @@ const QEMUOption qemu_options[] = {
     { "usbdevice", HAS_ARG, QEMU_OPTION_usbdevice },
     { "smp", HAS_ARG, QEMU_OPTION_smp },
     { "vnc", HAS_ARG, QEMU_OPTION_vnc },
+#if CONFIG_VNC_TLS
+    { "x509cacert", HAS_ARG, QEMU_OPTION_x509cacert },
+    { "x509cacrl", HAS_ARG, QEMU_OPTION_x509cacrl },
+    { "x509cert", HAS_ARG, QEMU_OPTION_x509cert },
+    { "x509key", HAS_ARG, QEMU_OPTION_x509key },
+#endif
 
     /* temporary options */
     { "usb", 0, QEMU_OPTION_usb },
@@ -7171,6 +7189,9 @@ int main(int argc, char **argv)
     int fds[2];
     const char *pid_file = NULL;
     VLANState *vlan;
+#if CONFIG_VNC_TLS
+    const char *x509cacert = NULL, *x509cacrl = NULL, *x509cert = NULL, 
*x509key = NULL;
+#endif
 
     LIST_INIT (&vm_change_state_head);
 #ifndef _WIN32
@@ -7648,6 +7669,20 @@ int main(int argc, char **argv)
            case QEMU_OPTION_vnc:
                vnc_display = optarg;
                break;
+#if CONFIG_VNC_TLS
+           case QEMU_OPTION_x509cacert:
+               x509cacert = optarg;
+               break;
+           case QEMU_OPTION_x509cacrl:
+               x509cacrl = optarg;
+               break;
+           case QEMU_OPTION_x509cert:
+               x509cert = optarg;
+               break;
+           case QEMU_OPTION_x509key:
+               x509key = optarg;
+               break;
+#endif
             case QEMU_OPTION_no_acpi:
                 acpi_enabled = 0;
                 break;
@@ -7945,6 +7980,10 @@ int main(int argc, char **argv)
         dumb_display_init(ds);
     } else if (vnc_display != NULL) {
         vnc_display_init(ds);
+#if CONFIG_VNC_TLS
+        if (vnc_set_x509_credentials(ds, x509cacert, x509cacrl, x509cert, 
x509key) < 0)
+            exit(1);
+#endif
         if (vnc_display_open(ds, vnc_display, NULL) < 0)
             exit(1);
     } else {
diff -r f38519b13575 vl.h
--- a/vl.h      Tue Jul 31 14:51:31 2007 -0400
+++ b/vl.h      Tue Jul 31 14:51:32 2007 -0400
@@ -971,6 +971,13 @@ void vnc_display_close(DisplayState *ds)
 void vnc_display_close(DisplayState *ds);
 int vnc_display_open(DisplayState *ds, const char *display, const char 
*password);
 void do_info_vnc(void);
+#if CONFIG_VNC_TLS
+int vnc_set_x509_credentials(DisplayState *ds,
+                            const char *cacert,
+                            const char *cacrl,
+                            const char *cert,
+                            const char *key);
+#endif
 
 /* x_keymap.c */
 extern uint8_t _translate_keycode(const int key);
diff -r f38519b13575 vnc.c
--- a/vnc.c     Tue Jul 31 14:51:31 2007 -0400
+++ b/vnc.c     Tue Jul 31 14:51:32 2007 -0400
@@ -142,6 +142,11 @@ struct VncState
 #if CONFIG_VNC_TLS
     int subauth;
     int x509verify;
+
+    char *x509cacert;
+    char *x509cacrl;
+    char *x509cert;
+    char *x509key;
 #endif
     char challenge[VNC_AUTH_CHALLENGE_SIZE];
 
@@ -1378,36 +1383,50 @@ static gnutls_anon_server_credentials vn
 }
 
 
-static gnutls_certificate_credentials_t vnc_tls_initialize_x509_cred(void)
+static gnutls_certificate_credentials_t vnc_tls_initialize_x509_cred(VncState 
*vs)
 {
     gnutls_certificate_credentials_t x509_cred;
     int ret;
-    struct stat st;
+
+    if (!vs->x509cacert) {
+       VNC_DEBUG("No CA x509 certificate specified\n");
+       return NULL;
+    }
+    if (!vs->x509cert) {
+       VNC_DEBUG("No server x509 certificate specified\n");
+       return NULL;
+    }
+    if (!vs->x509key) {
+       VNC_DEBUG("No server private key specified\n");
+       return NULL;
+    }
+
 
     if ((ret = gnutls_certificate_allocate_credentials(&x509_cred)) < 0) {
        VNC_DEBUG("Cannot allocate credentials %s\n", gnutls_strerror(ret));
        return NULL;
     }
-    if ((ret = gnutls_certificate_set_x509_trust_file(x509_cred, CA_FILE, 
GNUTLS_X509_FMT_PEM)) < 0) {
+    if ((ret = gnutls_certificate_set_x509_trust_file(x509_cred,
+                                                     vs->x509cacert,
+                                                     GNUTLS_X509_FMT_PEM)) < 
0) {
        VNC_DEBUG("Cannot load CA certificate %s\n", gnutls_strerror(ret));
        gnutls_certificate_free_credentials(x509_cred);
        return NULL;
     }
 
-    if ((ret = gnutls_certificate_set_x509_key_file (x509_cred, CERT_FILE, 
KEY_FILE,
+    if ((ret = gnutls_certificate_set_x509_key_file (x509_cred,
+                                                    vs->x509cert,
+                                                    vs->x509key,
                                                     GNUTLS_X509_FMT_PEM)) < 0) 
{
        VNC_DEBUG("Cannot load certificate & key %s\n", gnutls_strerror(ret));
        gnutls_certificate_free_credentials(x509_cred);
        return NULL;
     }
 
-    if (stat(CRL_FILE, &st) < 0) {
-       if (errno != ENOENT) {
-           gnutls_certificate_free_credentials(x509_cred);
-           return NULL;
-       }
-    } else {
-       if ((ret = gnutls_certificate_set_x509_crl_file(x509_cred, CRL_FILE, 
GNUTLS_X509_FMT_PEM)) < 0) {
+    if (vs->x509cacrl) {
+       if ((ret = gnutls_certificate_set_x509_crl_file(x509_cred,
+                                                       vs->x509cacrl,
+                                                       GNUTLS_X509_FMT_PEM)) < 
0) {
            VNC_DEBUG("Cannot load CRL %s\n", gnutls_strerror(ret));
            gnutls_certificate_free_credentials(x509_cred);
            return NULL;
@@ -1623,7 +1642,7 @@ static int vnc_start_tls(struct VncState
        }
 
        if (NEED_X509_AUTH(vs)) {
-           gnutls_certificate_server_credentials x509_cred = 
vnc_tls_initialize_x509_cred();
+           gnutls_certificate_server_credentials x509_cred = 
vnc_tls_initialize_x509_cred(vs);
            if (!x509_cred) {
                gnutls_deinit(vs->tls_session);
                vs->tls_session = NULL;
@@ -1888,6 +1907,43 @@ void vnc_display_init(DisplayState *ds)
     vnc_dpy_resize(vs->ds, 640, 400);
 }
 
+#if CONFIG_VNC_TLS
+int vnc_set_x509_credentials(DisplayState *ds,
+                            const char *cacert,
+                            const char *cacrl,
+                            const char *cert,
+                            const char *key)
+{
+    VncState *vs = ds ? (VncState *)ds->opaque : vnc_state;
+
+    if (vs->x509cacert) {
+       free(vs->x509cacert);
+       vs->x509cacert = NULL;
+    }
+    if (vs->x509cacrl) {
+       free(vs->x509cacrl);
+       vs->x509cacrl = NULL;
+    }
+    if (vs->x509cert) {
+       free(vs->x509cert);
+       vs->x509cert = NULL;
+    }
+    if (vs->x509key) {
+       free(vs->x509key);
+       vs->x509key = NULL;
+    }
+    if (cacert && !(vs->x509cacert = qemu_strdup(cacert)))
+       return -1;
+    if (cacrl && !(vs->x509cacrl = qemu_strdup(cacrl)))
+       return -1;
+    if (cert && !(vs->x509cert = qemu_strdup(cert)))
+       return -1;
+    if (key && !(vs->x509key = qemu_strdup(key)))
+       return -1;
+    return 0;
+}
+#endif /* CONFIG_VNC_TLS */
+
 void vnc_display_close(DisplayState *ds)
 {
     VncState *vs = ds ? (VncState *)ds->opaque : vnc_state;

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