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From: Eric Biggers <ebiggers@kernel.org>
To: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Cc: linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	bpf <bpf@vger.kernel.org>
Subject: Re: [PATCH 29/33] bpf: crypto: Use AES-CBC and AES-ECB libraries
Date: Tue, 7 Jul 2026 11:20:49 -0700	[thread overview]
Message-ID: <20260707182049.GA2238@quark> (raw)
In-Reply-To: <10eafa42-1142-4ed2-a485-f46c496bddfb@linux.dev>

On Tue, Jul 07, 2026 at 04:01:13PM +0100, Vadim Fedorenko wrote:
> cc +bpf
> 
> On 07/07/2026 06:34, Eric Biggers wrote:
> > BPF crypto was implemented using the lskcipher API, which doesn't seem
> > to be going anywhere.  It supports only "arc4", "cbc(aes)", "ecb(aes)",
> > and only with unoptimized implementations.
> > 
> > Library APIs also have been found to be a much better approach, for a
> > variety of reasons, including reduced overhead, greater flexibility, and
> > having to be explicit about the crypto algorithms that are supported.
> > 
> > We can safely ignore the theoretical "arc4" support in BPF crypto as
> > unused, which leaves "cbc(aes)" and "ecb(aes)".  Why these algorithms
> > were chosen, it's unclear.  Regardless, I'll assume that "cbc(aes)" and
> > "ecb(aes)" need to continue to be supported for backwards compatibility.
> 
> That was done for single use case of decrypting small blocks in TC
> layer with "cbc(aes)", with assumption of extending it later.

What protocol is using AES-CBC?  And is the kernel encrypting or
decrypting the data elsewhere, or it is just routing an encrypted packet
and only the BPF program decrypts it?

Does this mean the AES-ECB support is unnecessary and can be dropped?

> This change looks great, but it would be great to CC bpf folks just to
> be aware of the refactoring.

Sure.  I'm only looking to apply patches 1-13 for now; the rest (bpf,
fscrypt, keyrings, libceph, mac80211, macsec, mac802154, smb, ksmbd,
tipc) are proof of concept, showing how the library APIs can be used in
a wide range of kernel subsystems.  I didn't want to spam the entire
series to 20 mailing lists.  I'll resend them individually later.

Thanks!

- Eric

  reply	other threads:[~2026-07-07 18:20 UTC|newest]

Thread overview: 45+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-07  5:34 [PATCH 00/33] Library APIs for AES encryption modes Eric Biggers
2026-07-07  5:34 ` [PATCH 01/33] crypto: xts - Split out __xts_verify_key() helper Eric Biggers
2026-07-07 13:20   ` Thomas Huth
2026-07-07  5:34 ` [PATCH 02/33] lib/crypto: aes: Add ECB support Eric Biggers
2026-07-07 13:59   ` Thomas Huth
2026-07-07 19:22     ` Eric Biggers
2026-07-08  5:29       ` Thomas Huth
2026-07-07  5:34 ` [PATCH 03/33] lib/crypto: aes: Add CBC and CBC-CTS support Eric Biggers
2026-07-07  5:34 ` [PATCH 04/33] lib/crypto: aes: Add CTR and XCTR support Eric Biggers
2026-07-07  5:34 ` [PATCH 05/33] lib/crypto: aes: Add XTS support Eric Biggers
2026-07-07  5:34 ` [PATCH 06/33] lib/crypto: aes: Add GCM support Eric Biggers
2026-07-07  5:34 ` [PATCH 07/33] lib/crypto: aes: Add CCM support Eric Biggers
2026-07-07  5:34 ` [PATCH 08/33] crypto: aes - Add ECB support using library Eric Biggers
2026-07-07  5:34 ` [PATCH 09/33] crypto: aes - Add CBC and CBC-CTS " Eric Biggers
2026-07-07  5:34 ` [PATCH 10/33] crypto: aes - Add CTR and XCTR " Eric Biggers
2026-07-07  5:34 ` [PATCH 11/33] crypto: aes - Add XTS " Eric Biggers
2026-07-07  5:34 ` [PATCH 12/33] crypto: aes - Add GCM " Eric Biggers
2026-07-07  5:34 ` [PATCH 13/33] crypto: aes - Add CCM " Eric Biggers
2026-07-07  5:34 ` [PATCH 14/33] x86/sev: Use new AES-GCM library Eric Biggers
2026-07-07  5:34 ` [PATCH 15/33] lib/crypto: aesgcm: Remove old " Eric Biggers
2026-07-07  5:34 ` [PATCH 16/33] crypto: aes - Remove AES-CBC-MAC support Eric Biggers
2026-07-07  5:34 ` [PATCH 17/33] lib/crypto: aes: Remove aes_cbcmac_* functions Eric Biggers
2026-07-07  5:34 ` [PATCH 18/33] fscrypt: Use aes_ecb_encrypt() for v1 key derivation Eric Biggers
2026-07-07  5:34 ` [PATCH 19/33] KEYS: encrypted: Use AES-CBC library instead of crypto_skcipher Eric Biggers
2026-07-07  5:34 ` [PATCH 20/33] KEYS: trusted: dcp: Use AES-GCM library instead of crypto_aead Eric Biggers
2026-07-07  5:34 ` [PATCH 21/33] libceph: Use AES-CBC library in ceph_aes_crypt() Eric Biggers
2026-07-07  5:34 ` [PATCH 22/33] libceph: Reimplement messenger v2 encryption using AES-GCM library Eric Biggers
2026-07-07  5:34 ` [PATCH 23/33] wifi: mac80211: Use AES-CTR library in fils_aead.c Eric Biggers
2026-07-07  5:34 ` [PATCH 24/33] wifi: mac80211: Use AES-GCM library for GMAC suite Eric Biggers
2026-07-07  5:34 ` [PATCH 25/33] wifi: mac80211: Use crypto libraries for GCMP and CCMP suites Eric Biggers
2026-07-07  5:34 ` [PATCH 26/33] macsec: Use AES-GCM library instead of crypto_aead Eric Biggers
2026-07-07  5:34 ` [PATCH 27/33] wifi: ipw2x00: Use AES-CCM library Eric Biggers
2026-07-07  5:34 ` [PATCH 28/33] mac802154: Use AES-CCM and AES-CTR libraries Eric Biggers
2026-07-07  5:34 ` [PATCH 29/33] bpf: crypto: Use AES-CBC and AES-ECB libraries Eric Biggers
2026-07-07 15:01   ` Vadim Fedorenko
2026-07-07 18:20     ` Eric Biggers [this message]
2026-07-07 22:50       ` Vadim Fedorenko
2026-07-07 23:16         ` Eric Biggers
2026-07-08 11:47           ` Vadim Fedorenko
2026-07-07  5:35 ` [PATCH 30/33] bpf: crypto: Add AES-GCM support Eric Biggers
2026-07-07 15:02   ` Vadim Fedorenko
2026-07-07  5:35 ` [PATCH 31/33] smb: client: Use AES-GCM and AES-CCM libraries Eric Biggers
2026-07-07  5:35 ` [PATCH 32/33] ksmbd: " Eric Biggers
2026-07-07 10:51   ` Namjae Jeon
2026-07-07  5:35 ` [PATCH 33/33] net: tipc: Use AES-GCM library instead of crypto_aead Eric Biggers

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