linux-toradex.git/drivers/crypto/virtio, branch v6.19

crypto: engine - remove request batching support

2025-07-18T10:52:00+00:00

Remove request batching support from crypto_engine, as there are no
drivers using this feature and it doesn't really work that well.

Instead of doing batching based on backlog, a more optimal approach
would be for the user to handle the batching (similar to how IPsec
can hook into GSO to get 64K of data each time or how block encryption
can use unit sizes much greater than 4K).

Suggested-by: Herbert Xu 
Signed-off-by: Ovidiu Panait 
Reviewed-by: Horia Geantă 
Signed-off-by: Herbert Xu

crypto: virtio - Remove unused virtcrypto functions

2025-06-23T09:00:27+00:00

virtcrypto_devmgr_get_first() and virtcrypto_dev_in_use() were added in
2016 by
commit dbaf0624ffa5 ("crypto: add virtio-crypto driver")

but have remained unused.

Remove them.

Signed-off-by: Dr. David Alan Gilbert 
Reviewed-by: Zenghui Yu 
Signed-off-by: Herbert Xu

crypto: virtio - Erase some sensitive memory when it is freed

2025-03-15T07:08:54+00:00

virtcrypto_clear_request() does the same as the code here, but uses
kfree_sensitive() for one of the free operation.

So, better safe than sorry, use virtcrypto_clear_request() directly to
save a few lines of code and cleanly free the memory.

Signed-off-by: Christophe JAILLET 
Tested-by: Lei Yang 
Acked-by: Jason Wang 
Signed-off-by: Herbert Xu

crypto: virtio - Drop superfluous [as]kcipher_req pointer

2025-02-22T07:56:02+00:00

The request context virtio_crypto_{akcipher,sym}_request contains a
pointer to the [as]kcipher_request itself.

The pointer is superfluous as it can be calculated with container_of().

Drop the superfluous pointer.

Signed-off-by: Lukas Wunner 
Signed-off-by: Herbert Xu

crypto: virtio - Drop superfluous [as]kcipher_ctx pointer

2025-02-22T07:56:02+00:00

The request context virtio_crypto_{akcipher,sym}_request contains a
pointer to the transform context virtio_crypto_[as]kcipher_ctx.

The pointer is superfluous as it can be calculated with the cheap
crypto_akcipher_reqtfm() + akcipher_tfm_ctx() and
crypto_skcipher_reqtfm() + crypto_skcipher_ctx() combos.

Drop the superfluous pointer.

Signed-off-by: Lukas Wunner 
Signed-off-by: Herbert Xu

crypto: virtio - Drop superfluous ctx->tfm backpointer

2025-02-22T07:56:02+00:00

struct virtio_crypto_[as]kcipher_ctx contains a backpointer to struct
crypto_[as]kcipher which is superfluous in two ways:

First, it's not used anywhere.  Second, the context is embedded into
struct crypto_tfm, so one could just use container_of() to get from the
context to crypto_tfm and from there to crypto_[as]kcipher.

Drop the superfluous backpointer.

Signed-off-by: Lukas Wunner 
Signed-off-by: Herbert Xu

crypto: virtio - Simplify RSA key size caching

2025-02-22T07:56:02+00:00

When setting a public or private RSA key, the integer n is cached in the
transform context virtio_crypto_akcipher_ctx -- with the sole purpose of
calculating the key size from it in virtio_crypto_rsa_max_size().
It looks like this was copy-pasted from crypto/rsa.c.

Cache the key size directly instead of the integer n, thus simplifying
the code and reducing the memory footprint.

Signed-off-by: Lukas Wunner 
Signed-off-by: Herbert Xu

crypto: virtio - Fix kernel-doc of virtcrypto_dev_stop()

2025-02-22T07:56:02+00:00

It seems the kernel-doc of virtcrypto_dev_start() was copied verbatim to
virtcrypto_dev_stop().  Fix it.

Signed-off-by: Lukas Wunner 
Signed-off-by: Herbert Xu

crypto: virtio - Drop sign/verify operations

2024-10-05T05:22:04+00:00

The virtio crypto driver exposes akcipher sign/verify operations in a
user space ABI.  This blocks removal of sign/verify from akcipher_alg.

Herbert opines:

   "I would say that this is something that we can break.  Breaking it
    is no different to running virtio on a host that does not support
    these algorithms.  After all, a software implementation must always
    be present.

    I deliberately left akcipher out of crypto_user because the API
    is still in flux.  We should not let virtio constrain ourselves."
    https://lore.kernel.org/all/ZtqoNAgcnXnrYhZZ@gondor.apana.org.au/

   "I would remove virtio akcipher support in its entirety.  This API
    was never meant to be exposed outside of the kernel."
    https://lore.kernel.org/all/Ztqql_gqgZiMW8zz@gondor.apana.org.au/

Drop sign/verify support from virtio crypto.  There's no strong reason
to also remove encrypt/decrypt support, so keep it.

A key selling point of virtio crypto is to allow guest access to crypto
accelerators on the host.  So far the only akcipher algorithm supported
by virtio crypto is RSA.  Dropping sign/verify merely means that the
PKCS#1 padding is now always generated or verified inside the guest,
but the actual signature generation/verification (which is an RSA
decrypt/encrypt operation) may still use an accelerator on the host.

Generating or verifying the PKCS#1 padding is cheap, so a hardware
accelerator won't be of much help there.  Which begs the question
whether virtio crypto support for sign/verify makes sense at all.

It would make sense for the sign operation if the host has a security
chip to store asymmetric private keys.  But the kernel doesn't even
have an asymmetric_key_subtype yet for hardware-based private keys.
There's at least one rudimentary driver for such chips (atmel-ecc.c for
ATECC508A), but it doesn't implement the sign operation.  The kernel
would first have to grow support for a hardware asymmetric_key_subtype
and at least one driver implementing the sign operation before exposure
to guests via virtio makes sense.

Signed-off-by: Lukas Wunner 
Signed-off-by: Herbert Xu

virtio: rename virtio_find_vqs_info() to virtio_find_vqs()

2024-07-17T09:20:58+00:00

Since the original virtio_find_vqs() is no longer present, rename
virtio_find_vqs_info() back to virtio_find_vqs().

Signed-off-by: Jiri Pirko 
Message-Id: <20240708074814.1739223-20-jiri@resnulli.us>
Signed-off-by: Michael S. Tsirkin