Re: [PATCH] md: dm-crypt: Add Inline Encryption support for dmcrypt

From: Ladvine D Almeida <Ladvine.DAlmeida@synopsys.com>
To: Christoph Hellwig <hch@infradead.org>,
	Ladvine D Almeida <Ladvine.DAlmeida@synopsys.com>
Cc: Milan Broz <gmazyland@gmail.com>,
	Alasdair Kergon <agk@redhat.com>,
	Mike Snitzer <snitzer@redhat.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Manjunath M Bettegowda <Manjunath.MB@synopsys.com>,
	Prabu Thangamuthu <Prabu.T@synopsys.com>,
	Tejas Joglekar <Tejas.Joglekar@synopsys.com>,
	device-mapper development <dm-devel@redhat.com>,
	Joao Pinto <Joao.Pinto@synopsys.com>,
	"tytso@mit.edu" <tytso@mit.edu>,
	"jaegeuk@kernel.org" <jaegeuk@kernel.org>,
	"linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
	"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>
Subject: Re: [PATCH] md: dm-crypt: Add Inline Encryption support for dmcrypt
Date: Wed, 6 Jun 2018 10:04:14 +0000	[thread overview]
Message-ID: <BD7FB879CC136E419544C8E2AE7B9C3020C5D6@IN01WEMBXA.internal.synopsys.com> (raw)
In-Reply-To: 20180601081642.GA25973@infradead.org

On Friday 01 June 2018 09:16 AM, Christoph Hellwig wrote:
> On Wed, May 30, 2018 at 02:52:07PM +0000, Ladvine D Almeida wrote:
>> when the optional argument "perform_inline_encrypt" is set, we are not unconditionally sending the bio
>> to the block devices. The steps are explained below:
>> 1. user invokes the dm-setup command with the registered cipher "xts" and with the optional argument
>> "perform_inline_encrypt".
>> 2. dm-setup invokes the setkey function of the newly introduced algorithm, which finds the available key slots
>> to be programmed(UFS Host controller Inline Encryption engine has multiple keyslots), program the key slot,
>> and return the key slot index as return value of the set key function.
>> 3. When read/write operation happens, crypt_map() function in dm-crypt validates whether there is associated
>> key configuration index for the request. The Bio will be submitted directly in this case only with the associated
>> crypto context.
>> 4. Block device driver, eg. UFS host controller driver will create the Transfer requests as per this crypto context and
>> encryption happens inside the controller.
> Why isn't this all controlled by the ufs drivers, using helpers as
> required?

The idea is to make use of the existing utilities like dmsetup to configure the keys, mapping etc.

>
> Also why do we even need this API over just implementing TCG
> Opal/Opalite on the device?
>
TCG Opal/Opalite is FDE solution. right?

File Based Encryption is accomplished in the ext4/f2fs layer by invoking the registered algorithms from LKCF.

There is a scope for FBE, if the implementation is crypto API.

Regards,

Ladvine