Merge tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull crypto library updates from Eric Biggers:
"Add library APIs for most AES encryption mode

Merge tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull crypto library updates from Eric Biggers:
"Add library APIs for most AES encryption modes that are used in the
kernel (ECB, CBC, CBC-CTS, CTR, XCTR, XTS, GCM, CCM).

These AES modes have many in-kernel users that are currently using the
crypto_skcipher or crypto_aead APIs. These existing APIs are difficult
to use and inefficient. Until now, the lack of proper library support
for these has been the main gap in the crypto library.

This set of changes is the next stage of addressing it:

- Implement the new APIs on top of the existing support for
single-block AES in the library.

- Fully document the new APIs.

- Migrate the only user of the old AES-GCM library API to the new,
more flexible API; then remove the old API and its implementation.

- Wire up the new APIs to the traditional crypto API by adding
crypto_skcipher and crypto_aead algorithms.

This makes the new APIs be covered by the traditional crypto API's
self-tests. It also makes them be already used for real on systems
that don't have architecture-optimized code for these modes.

But most importantly, this is a prerequisite for migrating the
architecture-optimized code for these AES modes (i.e.
arch/*/crypto/aes*) into the library, which as usual will eliminate
a lot of redundant "glue" code.

Note that unlike some of the other algorithms that have been migrated
to the library, e.g. SHA-512, for these AES modes there was too much
to get done in one cycle. Nor did it make sense to handle these modes
one at a time, because they tend to be coupled together or depend on
each other, especially in the architecture-optimized AES code.

Thus, most of the benefits (reductions in lines of code, performance
improvements, etc.) will follow in later cycles when
architecture-optimized code is migrated into the library and users of
crypto_skcipher and crypto_aead are updated to use the new APIs.

The design of the new APIs was informed by writing proof-of-concept
patches for many kernel subsystems currently accessing these same
algorithms via crypto_skcipher or crypto_aead (patches 18-33 of
https://lore.kernel.org/r/20260707053503.209874-1-ebiggers@kernel.org/).

While those patches will be resent for real later, the total diffstat
for them was negative 1905 lines. So clearly the new APIs are quite a
bit easier to use and align better with what users actually need.

Besides the new AES encryption APIs, there are also a few changes for
improved AES-CMAC key and context zeroization"

* tag 'libcrypto-updates-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
mac80211: fils_aead: Use __cleanup() instead of memzero_explicit()
Bluetooth: SMP: clear the aes_cmac_key when done
smb: clear the aes_cmac_key and aes_cmac_ctx when done
lib/crypto: aes-cmac: Add zeroization functions
lib/crypto: aesgcm: Remove old AES-GCM library
x86/sev: Remove obsolete virtual address check
x86/sev: Use new AES-GCM library
crypto: aes - Add CCM support using library
crypto: aes - Add GCM support using library
crypto: aes - Add XTS support using library
crypto: aes - Add CTR and XCTR support using library
crypto: aes - Add CBC and CBC-CTS support using library
crypto: aes - Add ECB support using library
lib/crypto: aes: Add CCM support
lib/crypto: aes: Add GCM support
lib/crypto: aes: Add XTS support
lib/crypto: aes: Add CTR and XCTR support
lib/crypto: aes: Add CBC and CBC-CTS support
lib/crypto: aes: Add ECB support
crypto: xts - Split out __xts_verify_key() helper

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lib/crypto: aes: Add CCM support

Add support for AES-CCM to the crypto library.

This will be used to provide a streamlined implementation of the
"ccm(aes)" crypto_aead algorithm. Most users of "cc

lib/crypto: aes: Add CCM support

Add support for AES-CCM to the crypto library.

This will be used to provide a streamlined implementation of the
"ccm(aes)" crypto_aead algorithm. Most users of "ccm(aes)" will also be
able to switch to the library, which as usual will be faster and
simpler, e.g.:

- fs/smb/client/
- fs/smb/server/
- net/mac80211/
- net/mac802154/

(I've already written proof-of-concept patches for all the above, and
they helped inform the API design.)

As in the AES-GCM API, incremental operation is supported. It has to be
used carefully, especially when decrypting, but it makes the API general
enough to work well for all users.

The AES-CCM library code calls aes_cbcmac_blocks() directly, bypassing
the higher-level aes_cbcmac_init(), aes_cbcmac_update(), and
aes_cbcmac_final(). The latter set of functions is useful only for
AES-CCM, so they don't make sense to keep around and will be removed
once the "ccm(aes)" crypto_aead starts using the AES-CCM library.

Initial test coverage is provided by the crypto_aead support added in a
later commit. I'm planning a KUnit test suite as well.

Link: https://patch.msgid.link/20260715221153.246410-8-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

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lib/crypto: aes: Add GCM support

Add support for AES-GCM to the crypto library.

This will be used to provide streamlined implementations of the
"gcm(aes)" and "rfc4106(gcm(aes))" crypto_aead algori

lib/crypto: aes: Add GCM support

Add support for AES-GCM to the crypto library.

This will be used to provide streamlined implementations of the
"gcm(aes)" and "rfc4106(gcm(aes))" crypto_aead algorithms. Most users
of these will also be able to switch to the library, which as usual will
be faster and simpler, e.g.:

- drivers/net/macsec.c
- fs/smb/client/
- fs/smb/server/
- net/ceph/messenger_v2.c
- net/mac80211/ (for both GMAC and GCMP)
- net/tipc/crypto.c
- security/keys/trusted-keys/trusted_dcp.c

(I've already written proof-of-concept patches for all the above, and
they helped inform the API design.)

As usual, the architecture-optimized AES-GCM code will be migrated into
the library as well (using the hooks provided in this commit as well as
the GHASH ones), eliminating lots of repetitive boilerplate code.

Incremental en/decryption is supported. Incremental operation is a bit
controversial in AEAD APIs because users have to be careful not to
consume any decrypted data that hasn't been authenticated yet. But I do
think it's the right choice here. It's not fundamentally different from
the existing incremental MAC APIs, and it's the only approach that's
general enough to work well for all users in the kernel:

- An array of virtually-addressed buffers (like that used by
BoringSSL's EVP_AEAD_CTX_sealv() and EVP_AEAD_CTX_openv()) doesn't
work in the kernel in general, since in some cases the data for a
single AES-GCM message is contained in a large number of highmem
pages that each need to be mapped into memory individually. That
can be done efficiently only by using CPU-local mappings, but there
is a limited number of those.

Ceph messenger v2 is a great example, as it can send or receive up
to 32 MiB in a single AES-GCM message. And it needs the
en/decrypted data to go into a (potentially large) number of bvecs
provided by a custom iterator, as well as into four
virtually-addressed buffers, two of which can be large buffers in
the vmalloc region.

Even just allocating an array big enough to store all the pointers
can be problematic in the kernel. There are cases in which
decryption runs in GFP_NOIO context or even in softirq context,
where memory allocations are not as reliable as they normally are.

- Meanwhile, 'struct scatterlist' (the choice of crypto_aead) has
turned out to be really inconvenient for anyone who *does* just have
virtually-addressed buffers. This is especially true if they can be
in the vmalloc region, including the stack, as in that case the
conversion to a scatterlist has to be done page-by-page.

And even for users who have all of their data in bare 'struct page',
none of them actually use 'struct scatterlist' as their native data
structure anyway. They actually use skbs, bvecs, or other formats.

- iov_iter is attractive, but ultimately not general enough either
(considering the Ceph case for example), but also too general in
some ways (like having support for userspace addresses). Additional
iter types like ITER_SKB would help a bit, but bloating iov_iter
with more types would reduce performance elsewhere in the kernel.

Initial test coverage is provided by the crypto_aead support added in a
later commit. I'm planning a KUnit test suite as well.

Link: https://patch.msgid.link/20260715221153.246410-7-ebiggers@kernel.org
Link: https://patch.msgid.link/20260722021730.16897-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

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