From: Eric Biggers <ebiggers@kernel.org>
To: "Chang S. Bae" <chang.seok.bae@intel.com>
Cc: tglx@linutronix.de, bp@suse.de, dave.hansen@linux.intel.com,
mingo@kernel.org, luto@kernel.org, x86@kernel.org,
herbert@gondor.apana.org.au, linux-kernel@vger.kernel.org,
linux-crypto@vger.kernel.org, dan.j.williams@intel.com,
charishma1.gairuboyina@intel.com, kumar.n.dwarakanath@intel.com,
lalithambika.krishnakumar@intel.com, ravi.v.shankar@intel.com
Subject: Re: [PATCH v4 00/13] x86: Support Key Locker
Date: Wed, 15 Dec 2021 17:09:05 -0800 [thread overview]
Message-ID: <YbqRseO+TtuGQk5x@sol.localdomain> (raw)
In-Reply-To: <20211214005212.20588-1-chang.seok.bae@intel.com>
On Mon, Dec 13, 2021 at 04:51:59PM -0800, Chang S. Bae wrote:
> == Disk Encryption Use Case ==
>
> Disk encryption uses Key Locker to mitigate key exfiltration as follows:
>
> 1. Configuration for Key Locker: AES-KL shows up in /proc/crypto as a
> distinct cipher option. From there, tools like cryptsetup [5] can select
> AES-KL vs AES-NI. For example,
>
> $ cryptsetup luksFormat --cipher="capi:xts-aes-aeskl-plain" <device>
plain64 is supposed to be used these days, not plain.
> Note: AES-KL has a performance tradeoff. See details in 'Performance'
> below.
>
> 2. Disk encryption flow with key protection:
>
> * The cryptsetup utility is responsible for loading the volume key into the
> kernel's keyring and passing a reference of the key. Once dm-crypt [6]
> has set up the volume, user space is responsible for invalidating the key
> material so that only the key handle remains in memory. Cryptsetup does
> this, e.g. via crypt_free_volume_key() and crypt_safe_free().
>
> * The AES-KL code in the kernel's crypto library uses the key handle
> instead of the actual clear text key.
>
> == Non Use Cases ==
>
> Bare metal disk encryption is the only use case intended by these patches.
Since dm-crypt is the use case for these patches, you probably should CC this
patchset to dm-devel@redhat.com so that the dm-crypt developers are aware of it.
> +-----------+---------------+---------------+
> | Cipher | Encryption | Decryption |
> | (AES-KL) | (MiB/s) | (MiB/s) |
> +-----------+---------------+---------------+
> | AES-CBC | 505.3 | 2097.8 |
> | AES-XTS | 1130 | 696.4 |
> +-----------+-------------------------------+
Why is AES-XTS decryption so much slower than AES-XTS encryption? They should
be about the same.
Also, is the AES-CBC support really useful, given that for disk encryption,
AES-XTS is recommended over AES-CBC these days?
- Eric
next prev parent reply other threads:[~2021-12-16 1:09 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-14 0:51 [PATCH v4 00/13] x86: Support Key Locker Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 01/13] Documentation/x86: Document " Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 02/13] x86/cpufeature: Enumerate Key Locker feature Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 03/13] x86/insn: Add Key Locker instructions to the opcode map Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 04/13] x86/asm: Add a wrapper function for the LOADIWKEY instruction Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 05/13] x86/msr-index: Add MSRs for Key Locker internal wrapping key Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 06/13] x86/keylocker: Define Key Locker CPUID leaf Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 07/13] x86/cpu/keylocker: Load an internal wrapping key at boot-time Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 08/13] x86/power/keylocker: Restore internal wrapping key from the ACPI S3/4 sleep states Chang S. Bae
2021-12-17 15:42 ` Rafael J. Wysocki
2021-12-22 4:58 ` Bae, Chang Seok
2021-12-14 0:52 ` [PATCH v4 09/13] x86/cpu: Add a configuration and command line option for Key Locker Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 10/13] crypto: x86/aes - Prepare for a new AES implementation Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 11/13] crypto: x86/aes-kl - Support AES algorithm using Key Locker instructions Chang S. Bae
2021-12-24 17:42 ` Andy Lutomirski
2022-01-07 18:06 ` Bae, Chang Seok
2021-12-14 0:52 ` [PATCH v4 12/13] crypto: x86/aes-kl - Support CBC mode Chang S. Bae
2021-12-14 0:52 ` [PATCH v4 13/13] crypto: x86/aes-kl - Support XTS mode Chang S. Bae
2021-12-16 1:09 ` Eric Biggers [this message]
2022-01-05 21:55 ` [PATCH v4 00/13] x86: Support Key Locker Bae, Chang Seok
2022-01-06 5:07 ` Eric Biggers
2022-01-06 6:13 ` Bae, Chang Seok
2022-01-06 16:25 ` [dm-devel] " Milan Broz
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