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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 2D59DC433B4 for ; Fri, 14 May 2021 17:36:36 +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 DE2DE61352 for ; Fri, 14 May 2021 17:36:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE2DE61352 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]:33248 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lhbjn-0003Vs-1k for qemu-devel@archiver.kernel.org; Fri, 14 May 2021 13:36:35 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37518) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhbei-0002vG-B4 for qemu-devel@nongnu.org; Fri, 14 May 2021 13:31:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:53898) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lhbeg-0007ek-Jb for qemu-devel@nongnu.org; Fri, 14 May 2021 13:31:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621013478; 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=i0AqscuC0sCHNdnaq7GsvzkwtZ9TuDvo49dEJAQy1xE=; b=Jn8z4hFUxc9i8QnFuwRZrZNzKrNjhkOvd/ExWnL7tL4jf9JmtmqQQBivkZUlk1pksCugmg gCEkF82/veJcyk6jX2qLUw3oI4EZWuWB+XjzMYlfwzx8lQO29b7jrrgv+WaUhpuFyW8aYQ Gs3262/gof/EddYPxQlqdCf0elHS10k= 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-385-lrImU6OTM3mJXhWmfqg0dw-1; Fri, 14 May 2021 13:31:16 -0400 X-MC-Unique: lrImU6OTM3mJXhWmfqg0dw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6E17118BA280 for ; Fri, 14 May 2021 17:31:15 +0000 (UTC) Received: from localhost.redhat.com (ovpn-113-212.ams2.redhat.com [10.36.113.212]) by smtp.corp.redhat.com (Postfix) with ESMTP id ACAF45C1C4; Fri, 14 May 2021 17:31:14 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH 3/4] docs: recommend SCRAM-SHA-256 SASL mech instead of SHA-1 variant Date: Fri, 14 May 2021 18:31:09 +0100 Message-Id: <20210514173110.1397741-4-berrange@redhat.com> In-Reply-To: <20210514173110.1397741-1-berrange@redhat.com> References: <20210514173110.1397741-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 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: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.699, 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: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= 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. 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