linux-toradex.git/drivers/crypto/mediatek, branch v5.9-rc5

crypto: mediatek - use AES library for GCM key derivation

2020-07-16T11:49:04+00:00

The Mediatek accelerator driver calls into a dynamically allocated
skcipher of the ctr(aes) variety to perform GCM key derivation, which
involves AES encryption of a single block consisting of NUL bytes.

There is no point in using the skcipher API for this, so use the AES
library interface instead.

Signed-off-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu

crypto: mediatek - use crypto_shash_tfm_digest()

2020-05-08T05:32:13+00:00

Instead of manually allocating a 'struct shash_desc' on the stack and
calling crypto_shash_digest(), switch to using the new helper function
crypto_shash_tfm_digest() which does this for us.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: Replace zero-length array with flexible-array member

2020-03-06T01:28:21+00:00

The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva 
Reviewed-by: Horia Geantă 
Signed-off-by: Herbert Xu

crypto: remove propagation of CRYPTO_TFM_RES_* flags

2020-01-09T03:30:53+00:00

The CRYPTO_TFM_RES_* flags were apparently meant as a way to make the
->setkey() functions provide more information about errors.  But these
flags weren't actually being used or tested, and in many cases they
weren't being set correctly anyway.  So they've now been removed.

Also, if someone ever actually needs to start better distinguishing
->setkey() errors (which is somewhat unlikely, as this has been unneeded
for a long time), we'd be much better off just defining different return
values, like -EINVAL if the key is invalid for the algorithm vs.
-EKEYREJECTED if the key was rejected by a policy like "no weak keys".
That would be much simpler, less error-prone, and easier to test.

So just remove CRYPTO_TFM_RES_MASK and all the unneeded logic that
propagates these flags around.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: remove CRYPTO_TFM_RES_BAD_KEY_LEN

2020-01-09T03:30:53+00:00

The CRYPTO_TFM_RES_BAD_KEY_LEN flag was apparently meant as a way to
make the ->setkey() functions provide more information about errors.

However, no one actually checks for this flag, which makes it pointless.

Also, many algorithms fail to set this flag when given a bad length key.
Reviewing just the generic implementations, this is the case for
aes-fixed-time, cbcmac, echainiv, nhpoly1305, pcrypt, rfc3686, rfc4309,
rfc7539, rfc7539esp, salsa20, seqiv, and xcbc.  But there are probably
many more in arch/*/crypto/ and drivers/crypto/.

Some algorithms can even set this flag when the key is the correct
length.  For example, authenc and authencesn set it when the key payload
is malformed in any way (not just a bad length), the atmel-sha and ccree
drivers can set it if a memory allocation fails, and the chelsio driver
sets it for bad auth tag lengths, not just bad key lengths.

So even if someone actually wanted to start checking this flag (which
seems unlikely, since it's been unused for a long time), there would be
a lot of work needed to get it working correctly.  But it would probably
be much better to go back to the drawing board and just define different
return values, like -EINVAL if the key is invalid for the algorithm vs.
-EKEYREJECTED if the key was rejected by a policy like "no weak keys".
That would be much simpler, less error-prone, and easier to test.

So just remove this flag.

Signed-off-by: Eric Biggers 
Reviewed-by: Horia Geantă 
Signed-off-by: Herbert Xu

crypto: mediatek - switch to skcipher API

2019-11-17T01:02:47+00:00

Commit 7a7ffe65c8c5 ("crypto: skcipher - Add top-level skcipher interface")
dated 20 august 2015 introduced the new skcipher API which is supposed to
replace both blkcipher and ablkcipher. While all consumers of the API have
been converted long ago, some producers of the ablkcipher remain, forcing
us to keep the ablkcipher support routines alive, along with the matching
code to expose [a]blkciphers via the skcipher API.

So switch this driver to the skcipher API, allowing us to finally drop the
ablkcipher code in the near future.

Cc: Matthias Brugger 
Cc: linux-mediatek@lists.infradead.org
Signed-off-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu

crypto: mediatek - remove redundant bitwise-or

2019-11-01T05:38:31+00:00

Bitwise-or'ing 0xffffffff with the u32 variable ctr is the same result
as assigning the value to ctr.  Remove the redundant bitwise-or and
just use an assignment.

Addresses-Coverity: ("Suspicious &= or |= constant expression")
Signed-off-by: Colin Ian King 
Signed-off-by: Herbert Xu

crypto: mediatek - fix incorrect crypto key setting

2019-09-05T04:36:54+00:00

Record crypto key to context during setkey and set the key to
transform state buffer in encrypt/decrypt process.

Signed-off-by: Vic Wu 
Tested-by: John Crispin 
Signed-off-by: Herbert Xu

crypto: mediatek - add support to OFB/CFB mode

2019-09-05T04:36:54+00:00

This patch adds support to OFB/CFB mode.

Signed-off-by: Ryder Lee 
Signed-off-by: Vic Wu 
Signed-off-by: Herbert Xu

crypto: mediatek - only treat EBUSY as transient if backlog

2019-09-05T04:36:54+00:00

The driver was treating -EBUSY as indication of queueing to backlog
without checking that backlog is enabled for the request.

Fix it by checking request flags.

Signed-off-by: Ryder Lee 
Signed-off-by: Vic Wu 
Signed-off-by: Herbert Xu