From patchwork Tue May 1 21:20:40 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Moore X-Patchwork-Id: 156250 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id F2D16B6EF1 for ; Wed, 2 May 2012 08:08:05 +1000 (EST) Received: from localhost ([::1]:40526 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SPLEp-0000mA-KM for incoming@patchwork.ozlabs.org; Tue, 01 May 2012 18:08:03 -0400 Received: from eggs.gnu.org ([208.118.235.92]:38024) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SPLEi-0000ln-51 for qemu-devel@nongnu.org; Tue, 01 May 2012 18:07:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SPLEg-0005LE-3I for qemu-devel@nongnu.org; Tue, 01 May 2012 18:07:55 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23671) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SPLEf-0005L1-Q3 for qemu-devel@nongnu.org; Tue, 01 May 2012 18:07:54 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q41M7pTZ017837 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 1 May 2012 18:07:51 -0400 Received: from [127.0.0.1] (vpn-9-9.rdu.redhat.com [10.11.9.9]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id q41LKeqk017822; Tue, 1 May 2012 17:20:41 -0400 To: qemu-devel@nongnu.org From: Paul Moore Date: Tue, 01 May 2012 17:20:40 -0400 Message-ID: <20120501212040.27850.27184.stgit@sifl> User-Agent: StGit/0.16 MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] vnc: disable VNC password authentication (security type 2) when in FIPS mode X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org FIPS 140-2 requires disabling certain ciphers, including DES, which is used by VNC to obscure passwords when they are sent over the network. The solution for FIPS users is to disable the use of VNC password auth when the host system is operating in FIPS mode. This patch causes qemu to emits a syslog entry indicating that VNC password auth is disabled when it detects the host is running in FIPS mode, and unless a VNC password was specified on the command line it continues normally. However, if a VNC password was given on the command line, qemu fails with an error message to stderr explaining that that VNC password auth is not allowed in FIPS mode. Signed-off-by: Paul Moore --- qemu-doc.texi | 8 +++++--- ui/vnc.c | 32 ++++++++++++++++++++++++++++++++ ui/vnc.h | 1 + 3 files changed, 38 insertions(+), 3 deletions(-) diff --git a/qemu-doc.texi b/qemu-doc.texi index e5d7ac4..f9b113e 100644 --- a/qemu-doc.texi +++ b/qemu-doc.texi @@ -1124,9 +1124,11 @@ the protocol limits passwords to 8 characters it should not be considered to provide high security. The password can be fairly easily brute-forced by a client making repeat connections. For this reason, a VNC server using password authentication should be restricted to only listen on the loopback interface -or UNIX domain sockets. Password authentication is requested with the @code{password} -option, and then once QEMU is running the password is set with the monitor. Until -the monitor is used to set the password all clients will be rejected. +or UNIX domain sockets. Password authentication is not supported when operating +in FIPS 140-2 compliance mode as it requires the use of the DES cipher. Password +authentication is requested with the @code{password} option, and then once QEMU +is running the password is set with the monitor. Until the monitor is used to +set the password all clients will be rejected. @example qemu [...OPTIONS...] -vnc :1,password -monitor stdio diff --git a/ui/vnc.c b/ui/vnc.c index deb9ecd..620791e 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -32,6 +32,7 @@ #include "acl.h" #include "qemu-objects.h" #include "qmp-commands.h" +#include #define VNC_REFRESH_INTERVAL_BASE 30 #define VNC_REFRESH_INTERVAL_INC 50 @@ -48,6 +49,24 @@ static DisplayChangeListener *dcl; static int vnc_cursor_define(VncState *vs); static void vnc_release_modifiers(VncState *vs); +static int fips_enabled(void) +{ + int enabled = 0; + char value; + FILE *fds; + + fds = fopen("/proc/sys/crypto/fips_enabled", "r"); + if (fds == NULL) { + return 0; + } + if (fread(&value, sizeof(value), 1, fds) == 1 && value == '1') { + enabled = 1; + } + fclose(fds); + + return enabled; +} + static void vnc_set_share_mode(VncState *vs, VncShareMode mode) { #ifdef _VNC_DEBUG @@ -2748,6 +2767,12 @@ void vnc_display_init(DisplayState *ds) dcl->idle = 1; vnc_display = vs; + vs->fips = fips_enabled(); + VNC_DEBUG("FIPS mode %s\n", (vs->fips ? "enabled" : "disabled")); + if (vs->fips) { + syslog(LOG_NOTICE, "Disabling VNC password auth due to FIPS mode\n"); + } + vs->lsock = -1; vs->ds = ds; @@ -2892,6 +2917,13 @@ int vnc_display_open(DisplayState *ds, const char *display) while ((options = strchr(options, ','))) { options++; if (strncmp(options, "password", 8) == 0) { + if (vs->fips) { + fprintf(stderr, + "VNC password auth disabled due to FIPS mode\n"); + g_free(vs->display); + vs->display = NULL; + return -1; + } password = 1; /* Require password auth */ } else if (strncmp(options, "reverse", 7) == 0) { reverse = 1; diff --git a/ui/vnc.h b/ui/vnc.h index a851ebd..8746a98 100644 --- a/ui/vnc.h +++ b/ui/vnc.h @@ -160,6 +160,7 @@ struct VncDisplay char *display; char *password; time_t expires; + int fips; int auth; bool lossy; bool non_adaptive;