The CRYPTO_TFM_RES_WEAK_KEY 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.
There are also no tests that verify that all algorithms actually set (or
don't set) it correctly.
This is also the last remaining CRYPTO_TFM_RES_* flag, which means that
it's the only thing still needing all the boilerplate code which
propagates these flags around from child => parent tfms.
And if someone ever needs to distinguish this error in the future (which
is somewhat unlikely, as it's been unneeded for a long time), it would
be much better to just define a new return value like -EKEYREJECTED.
That would be much simpler, less error-prone, and easier to test.
So just remove this flag.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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 <ebiggers@google.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that all users of the deprecated ablkcipher interface have been
moved to the skcipher interface, ablkcipher is no longer used and
can be removed.
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Another one for the cipher museum: split off DES core processing into
a separate module so other drivers (mostly for crypto accelerators)
can reuse the code without pulling in the generic DES cipher itself.
This will also permit the cipher interface to be made private to the
crypto API itself once we move the only user in the kernel (CIFS) to
this library interface.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The recently added helper routine to perform key strength validation
of triple DES keys is slightly inadequate, since it comes in two versions,
neither of which are highly useful for anything other than skciphers (and
many drivers still use the older blkcipher interfaces).
So let's add a new helper and, considering that this is a helper function
that is only intended to be used by crypto code itself, put it in a new
des.h header under crypto/internal.
While at it, implement a similar helper for single DES, so that we can
start replacing the pattern of calling des_ekey() into a temp buffer
that occurs in many drivers in drivers/crypto.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Eric Biggers