From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E7E2CC2B9F4 for ; Mon, 14 Jun 2021 14:18:37 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 86EF061241 for ; Mon, 14 Jun 2021 14:18:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 86EF061241 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:54554 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lsnQC-0007We-Nh for qemu-devel@archiver.kernel.org; Mon, 14 Jun 2021 10:18:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34690) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lsnOF-0004Bl-Cg for qemu-devel@nongnu.org; Mon, 14 Jun 2021 10:16:35 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38033) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lsnOD-0007wA-IH for qemu-devel@nongnu.org; Mon, 14 Jun 2021 10:16:35 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1623680193; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R+xFxhM9zGWXPgxeV929BCHsrM/ywnmyEPP/qN/YtKE=; b=aiJDXd3k0L9UFDxfeFIDeQRSlT9TY2dvnlhyunFsvTrSOgNebfI6l3t8sZYYiDM2B2Ha7T 1yClb4oes/Wbx/+ODPfa2JImfiCwbbUQNOZRZKsWFAqf9JbsDCh/2/Y26iAixO2xmDhqUF YUU36k+YxcRcleoTuqEJ/1MT7W1+htQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-495-ujPbJSB1NWOYBQ2LPOIcnQ-1; Mon, 14 Jun 2021 10:16:29 -0400 X-MC-Unique: ujPbJSB1NWOYBQ2LPOIcnQ-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 388EB193F564; Mon, 14 Jun 2021 14:16:28 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-115-55.ams2.redhat.com [10.36.115.55]) by smtp.corp.redhat.com (Postfix) with ESMTP id 729D119C46; Mon, 14 Jun 2021 14:16:18 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Subject: [PULL 04/13] docs: recommend SCRAM-SHA-256 SASL mech instead of SHA-1 variant Date: Mon, 14 Jun 2021 15:15:40 +0100 Message-Id: <20210614141549.100410-5-berrange@redhat.com> In-Reply-To: <20210614141549.100410-1-berrange@redhat.com> References: <20210614141549.100410-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=216.205.24.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.2, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= , qemu-block@nongnu.org, Juan Quintela , Michael Roth , Richard Henderson , Markus Armbruster , Max Reitz , Gerd Hoffmann , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Paolo Bonzini , "Dr. David Alan Gilbert" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The SHA-256 variant better meats modern security expectations. Also warn that the password file is storing entries in clear text. Reviewed-by: Marc-André Lureau Signed-off-by: Daniel P. Berrangé --- docs/system/vnc-security.rst | 7 ++++--- qemu.sasl | 11 ++++++----- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/docs/system/vnc-security.rst b/docs/system/vnc-security.rst index 830f6acc73..4c1769eeb8 100644 --- a/docs/system/vnc-security.rst +++ b/docs/system/vnc-security.rst @@ -168,7 +168,7 @@ used is drastically reduced. In fact only the GSSAPI SASL mechanism provides an acceptable level of security by modern standards. Previous versions of QEMU referred to the DIGEST-MD5 mechanism, however, it has multiple serious flaws described in detail in RFC 6331 and thus should -never be used any more. The SCRAM-SHA-1 mechanism provides a simple +never be used any more. The SCRAM-SHA-256 mechanism provides a simple username/password auth facility similar to DIGEST-MD5, but does not support session encryption, so can only be used in combination with TLS. @@ -191,11 +191,12 @@ reasonable configuration is :: - mech_list: scram-sha-1 + mech_list: scram-sha-256 sasldb_path: /etc/qemu/passwd.db The ``saslpasswd2`` program can be used to populate the ``passwd.db`` -file with accounts. +file with accounts. Note that the ``passwd.db`` file stores passwords +in clear text. Other SASL configurations will be left as an exercise for the reader. Note that all mechanisms, except GSSAPI, should be combined with use of diff --git a/qemu.sasl b/qemu.sasl index fb8a92ba58..abdfc686be 100644 --- a/qemu.sasl +++ b/qemu.sasl @@ -19,15 +19,15 @@ mech_list: gssapi # If using TLS with VNC, or a UNIX socket only, it is possible to # enable plugins which don't provide session encryption. The -# 'scram-sha-1' plugin allows plain username/password authentication +# 'scram-sha-256' plugin allows plain username/password authentication # to be performed # -#mech_list: scram-sha-1 +#mech_list: scram-sha-256 # You can also list many mechanisms at once, and the VNC server will # negotiate which to use by considering the list enabled on the VNC # client. -#mech_list: scram-sha-1 gssapi +#mech_list: scram-sha-256 gssapi # Some older builds of MIT kerberos on Linux ignore this option & # instead need KRB5_KTNAME env var. @@ -38,7 +38,8 @@ mech_list: gssapi # mechanism this can be commented out. keytab: /etc/qemu/krb5.tab -# If using scram-sha-1 for username/passwds, then this is the file +# If using scram-sha-256 for username/passwds, then this is the file # containing the passwds. Use 'saslpasswd2 -a qemu [username]' -# to add entries, and 'sasldblistusers2 -f [sasldb_path]' to browse it +# to add entries, and 'sasldblistusers2 -f [sasldb_path]' to browse it. +# Note that this file stores passwords in clear text. #sasldb_path: /etc/qemu/passwd.db -- 2.31.1