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>
The essiv and hmac templates refuse to use any hash algorithm that has a
->setkey() function, which includes not just algorithms that always need
a key, but also algorithms that optionally take a key.
Previously the only optionally-keyed hash algorithms in the crypto API
were non-cryptographic algorithms like crc32, so this didn't really
matter. But that's changed with BLAKE2 support being added. BLAKE2
should work with essiv and hmac, just like any other cryptographic hash.
Fix this by allowing the use of both algorithms without a ->setkey()
function and algorithms that have the OPTIONAL_KEY flag set.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
kfree has taken null pointer check into account. so it is safe to
remove the unnecessary check.
Signed-off-by: Chen Wandun <chenwandun@huawei.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Now that all "blkcipher" algorithms have been converted to "skcipher",
remove the blkcipher algorithm type.
The skcipher (symmetric key cipher) algorithm type was introduced a few
years ago to replace both blkcipher and ablkcipher (synchronous and
asynchronous block cipher). The advantages of skcipher include:
- A much less confusing name, since none of these algorithm types have
ever actually been for raw block ciphers, but rather for all
length-preserving encryption modes including block cipher modes of
operation, stream ciphers, and other length-preserving modes.
- It unified blkcipher and ablkcipher into a single algorithm type
which supports both synchronous and asynchronous implementations.
Note, blkcipher already operated only on scatterlists, so the fact
that skcipher does too isn't a regression in functionality.
- Better type safety by using struct skcipher_alg, struct
crypto_skcipher, etc. instead of crypto_alg, crypto_tfm, etc.
- It sometimes simplifies the implementations of algorithms.
Also, the blkcipher API was no longer being tested.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Implement a template that wraps a (skcipher,shash) or (aead,shash) tuple
so that we can consolidate the ESSIV handling in fscrypt and dm-crypt and
move it into the crypto API. This will result in better test coverage, and
will allow future changes to make the bare cipher interface internal to the
crypto subsystem, in order to increase robustness of the API against misuse.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
