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=-5.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 AB482C433FF for ; Sun, 28 Jul 2019 19:30:40 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 805E12075B for ; Sun, 28 Jul 2019 19:30:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="tFDyrpEs" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 805E12075B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mit.edu Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=UJ/tT4/0lqQBNk+gN9nU6quxI96YiTqEh0Gz8AsSBgw=; b=tFDyrpEs0eoSjb vWnMtPiAb3z5WksSx1yUHuTR93JFkYpAr6CKXAMARgG1axzlx/OyLyNDu5cCp5VCwla+4LbHEx5Mt scXfZDnX21L0qshKcCO6vMFit3fxUeOVHrf0n1OgS/dDr51InlsCkHzFYbz7wix5Rf7jLlFkz/RQV Ure7p64MJCXfS1CA3o5H2aTtOZEnrUdOkKV7uamTyLFDjRY/ob8oLRHbOHVFNGBJs9O6n3G69nsLr L2A64GzoeeFYQLm0kzIIWAMEbs/6JjMkUgtRhHLuer54F1c+VfMQ4tBENgqampNrG6NMvFCayqzTD 2jb/FSoUaaZjJGx82v7w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hrosD-0003Ou-8a; Sun, 28 Jul 2019 19:30:25 +0000 Received: from outgoing-auth-1.mit.edu ([18.9.28.11] helo=outgoing.mit.edu) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hros9-0003Oa-CK for linux-mtd@lists.infradead.org; Sun, 28 Jul 2019 19:30:23 +0000 Received: from callcc.thunk.org (96-72-102-169-static.hfc.comcastbusiness.net [96.72.102.169] (may be forged)) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id x6SJUDhE009303 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sun, 28 Jul 2019 15:30:14 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 7DDB54202F5; Sun, 28 Jul 2019 15:30:12 -0400 (EDT) Date: Sun, 28 Jul 2019 15:30:12 -0400 From: "Theodore Y. Ts'o" To: Eric Biggers Subject: Re: [PATCH v7 08/16] fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctl Message-ID: <20190728193012.GH6088@mit.edu> References: <20190726224141.14044-1-ebiggers@kernel.org> <20190726224141.14044-9-ebiggers@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190726224141.14044-9-ebiggers@kernel.org> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190728_123022_532019_A890A92C X-CRM114-Status: GOOD ( 13.90 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Satya Tangirala , linux-api@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, keyrings@vger.kernel.org, linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, Paul Crowley Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org Archived-At: List-Archive: On Fri, Jul 26, 2019 at 03:41:33PM -0700, Eric Biggers wrote: > From: Eric Biggers > > Add a new fscrypt ioctl, FS_IOC_GET_ENCRYPTION_KEY_STATUS. Given a key > specified by 'struct fscrypt_key_specifier' (the same way a key is > specified for the other fscrypt key management ioctls), it returns > status information in a 'struct fscrypt_get_key_status_arg'. > > The main motivation for this is that applications need to be able to > check whether an encrypted directory is "unlocked" or not, so that they > can add the key if it is not, and avoid adding the key (which may > involve prompting the user for a passphrase) if it already is. > > It's possible to use some workarounds such as checking whether opening a > regular file fails with ENOKEY, or checking whether the filenames "look > like gibberish" or not. However, no workaround is usable in all cases. > > Like the other key management ioctls, the keyrings syscalls may seem at > first to be a good fit for this. Unfortunately, they are not. Even if > we exposed the keyring ID of the ->s_master_keys keyring and gave > everyone Search permission on it (note: currently the keyrings > permission system would also allow everyone to "invalidate" the keyring > too), the fscrypt keys have an additional state that doesn't map cleanly > to the keyrings API: the secret can be removed, but we can be still > tracking the files that were using the key, and the removal can be > re-attempted or the secret added again. > > After later patches, some applications will also need a way to determine > whether a key was added by the current user vs. by some other user. > Reserved fields are included in fscrypt_get_key_status_arg for this and > other future extensions. > > Signed-off-by: Eric Biggers Looks good, feel free to add: Reviewed-by: Theodore Ts'o ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/