From nobody Tue Feb 10 20:49:41 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1597225438; cv=none; d=zohomail.com; s=zohoarc; b=OQWjkuLI0KdxUtDKp1qcgkHoOF12zLcaYO8Zw0eO+iMKeWNrLsD/HiF28DCk2muvE6kUGXeAe8uxeAjAaoQey2dHbFrfDNqw1od9CCI0KGlTJHyJY65JB4kS4BfWaTCD9IeR7LOfpMCFO4s4vbv2pZ4S4GsvRKXPQpcq9wgEThk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1597225438; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=qJHnNidFMFADmsdaExyya8m1j73y6AGQzKJl69XEeVc=; b=bg4YpSenCOfDWVDsQaoWpdVW0238oi28weks++aE6hM0GGjn6vI5utg5jCR3OeIqiXoUya6mhU6OlxG3XC1MrjwUHvdbhf1kG3jtcKPNp4GHRrBcll1tmZq5fxM0JxuAIw1+LNtn6HDiVpZ5q/o0P70VCUoDBM/4G8vZiNwCDQg= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1597225438862646.9895371873722; Wed, 12 Aug 2020 02:43:58 -0700 (PDT) Received: from localhost ([::1]:58928 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1k5nIb-0003V1-Ix for importer@patchew.org; Wed, 12 Aug 2020 05:43:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:42258) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k5nHS-00022d-EK for qemu-devel@nongnu.org; Wed, 12 Aug 2020 05:42:46 -0400 Received: from gate-2.cri.epita.net ([163.5.55.20]:40864 helo=mail-2.srv.cri.epita.fr) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1k5nHQ-0006kH-BE for qemu-devel@nongnu.org; Wed, 12 Aug 2020 05:42:46 -0400 Received: from MattGorko-Laptop.localdomain (unknown [78.194.154.81]) (Authenticated sender: cesar.belley) by mail-2.srv.cri.epita.fr (Postfix) with ESMTPSA id 2C5DB4150B; Wed, 12 Aug 2020 11:42:43 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=lse.epita.fr; s=cri; t=1597225363; bh=mXjkHDuBA2Pelp7FvLqsvotpGAVI+Oj+eqQ5xB79ZVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xlvk/cTHYNzxQP3ZauXx6odIb4WJK1dEADQYWb2ITyIx/IFc5D4ykBSfsvlDiCVW9 oVwhyNA36YMPx2C6hP5DgyD+zt+vB34o89QnPUByTIbKC3D7etpB+CFRN14WQVb5td 7T3XiDtAgCBFcqD984xK7idOaQiEco/ZlRiXWWT8= From: =?UTF-8?q?C=C3=A9sar=20Belley?= To: qemu-devel@nongnu.org Subject: [PATCH 02/13] docs: Add USB U2F key device documentation Date: Wed, 12 Aug 2020 11:41:24 +0200 Message-Id: <20200812094135.20550-3-cesar.belley@lse.epita.fr> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200812094135.20550-1-cesar.belley@lse.epita.fr> References: <20200812094135.20550-1-cesar.belley@lse.epita.fr> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=163.5.55.20; envelope-from=srs0=nna4=bw=lse.epita.fr=cesar.belley@cri.epita.fr; helo=mail-2.srv.cri.epita.fr X-detected-operating-system: by eggs.gnu.org: First seen = 2020/08/12 05:42:10 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] X-Spam_score_int: -16 X-Spam_score: -1.7 X-Spam_bar: - X-Spam_report: (-1.7 / 5.0 requ) BAYES_00=-1.9, DKIM_INVALID=0.1, DKIM_SIGNED=0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=no 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?C=C3=A9sar=20Belley?= , kraxel@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Add USB U2F key device documentation: - USB U2F key device - Building - Using u2f-emulated - Using u2f-passthru - Libu2f-emu Signed-off-by: C=C3=A9sar Belley --- docs/u2f.txt | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 101 insertions(+) create mode 100644 docs/u2f.txt diff --git a/docs/u2f.txt b/docs/u2f.txt new file mode 100644 index 0000000000..f60052882e --- /dev/null +++ b/docs/u2f.txt @@ -0,0 +1,101 @@ +QEMU U2F Key Device Documentation. + +Contents +1. USB U2F key device +2. Building +3. Using u2f-emulated +4. Using u2f-passthru +5. Libu2f-emu + +1. USB U2F key device + +U2F is an open authentication standard that enables relying parties +exposed to the internet to offer a strong second factor option for end +user authentication. + +The standard brings many advantages to both parties, client and server, +allowing to reduce over-reliance on passwords, it increases authentication +security and simplifies passwords. + +The second factor is materialized by a device implementing the U2F +protocol. In case of a USB U2F security key, it is a USB HID device +that implements the U2F protocol. + +In Qemu, the USB U2F key device offers a dedicated support of U2F, allowing +guest USB FIDO/U2F security keys operating in two possible modes: +pass-through and emulated. + +The pass-through mode consists of passing all requests made from the guest +to the physical security key connected to the host machine and vice versa. +In addition, the dedicated pass-through allows to have a U2F security key +shared on several guests which is not possible with a simple host device +assignment pass-through. + +The emulated mode consists of completely emulating the behavior of an +U2F device through software part. Libu2f-emu is used for that. + + +2. Building + +To ensure the build of the u2f-emulated device variant which depends +on libu2f-emu: configuring and building: + + ./configure --enable-u2f && make + + +3. Using u2f-emulated + +To work, an emulated U2F device must have four elements: + * ec x509 certificate + * ec private key + * counter (four bytes value) + * 48 bytes of entropy (random bits) + +To use this type of device, this one has to be configured, and these +four elements must be passed one way or another. + +Assuming that you have a working libu2f-emu installed on the host. +There are three possible ways of configurations: + * ephemeral + * setup directory + * manual + +Ephemeral is the simplest way to configure, it lets the device generate +all the elements it needs for a single use of the lifetime of the device. + + qemu -usb -device u2f-emulated + +Setup directory allows to configure the device from a directory containing +four files: + * certificate.pem: ec x509 certificate + * private-key.pem: ec private key + * counter: counter value + * entropy: 48 bytes of entropy + + qemu -usb -device u2f-emulated,dir=3D$dir + +Manual allows to configure the device more finely by specifying each +of the elements necessary for the device: + * cert + * priv + * counter + * entropy + + qemu -usb -device u2f-emulated,cert=3D$DIR1/$FILE1,priv=3D$DIR2/$FILE2= ,counter=3D$DIR3/$FILE3,entropy=3D$DIR4/$FILE4 + + +4. Using u2f-passthru + +On the host specify the u2f-passthru device with a suitable hidraw: + + qemu -usb -device u2f-passthru,hidraw=3D/dev/hidraw0 + + +5. Libu2f-emu + +The u2f-emulated device uses libu2f-emu for the U2F key emulation. Libu2f-= emu +implements completely the U2F protocol device part for all specified +transport given by the FIDO Alliance. + +For more information about libu2f-emu see this page: +https://github.com/MattGorko/libu2f-emu. --=20 2.28.0