kernel.git/crypto/ahash.c, branch linux-4.14.y

crypto: hash - set CRYPTO_TFM_NEED_KEY if ->setkey() fails

2019-03-23T13:35:18Z

commit ba7d7433a0e998c902132bd47330e355a1eaa894 upstream. Some algorithms have a ->setkey() method that is not atomic, in the sense that setting a key can fail after changes were already made to the tfm context. In this case, if a key was already set the tfm can end up in a state that corresponds to neither the old key nor the new key. It's not feasible to make all ->setkey() methods atomic, especially ones that have to key multiple sub-tfms. Therefore, make the crypto API set CRYPTO_TFM_NEED_KEY if ->setkey() fails and the algorithm requires a key, to prevent the tfm from being used until a new key is set. Note: we can't set CRYPTO_TFM_NEED_KEY for OPTIONAL_KEY algorithms, so ->setkey() for those must nevertheless be atomic. That's fine for now since only the crc32 and crc32c algorithms set OPTIONAL_KEY, and it's not intended that OPTIONAL_KEY be used much. [Cc stable mainly because when introducing the NEED_KEY flag I changed AF_ALG to rely on it; and unlike in-kernel crypto API users, AF_ALG previously didn't have this problem. So these "incompletely keyed" states became theoretically accessible via AF_ALG -- though, the opportunities for causing real mischief seem pretty limited.] Fixes: 9fa68f620041 ("crypto: hash - prevent using keyed hashes without setting key") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ahash - fix another early termination in hash walk

2019-03-23T13:35:10Z

commit 77568e535af7c4f97eaef1e555bf0af83772456c upstream. Hash algorithms with an alignmask set, e.g. "xcbc(aes-aesni)" and "michael_mic", fail the improved hash tests because they sometimes produce the wrong digest. The bug is that in the case where a scatterlist element crosses pages, not all the data is actually hashed because the scatterlist walk terminates too early. This happens because the 'nbytes' variable in crypto_hash_walk_done() is assigned the number of bytes remaining in the page, then later interpreted as the number of bytes remaining in the scatterlist element. Fix it. Fixes: 900a081f6912 ("crypto: ahash - Fix early termination in hash walk") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: ahash - Fix early termination in hash walk

2018-04-08T12:26:31Z

commit 900a081f6912a8985dc15380ec912752cb66025a upstream. When we have an unaligned SG list entry where there is no leftover aligned data, the hash walk code will incorrectly return zero as if the entire SG list has been processed. This patch fixes it by moving onto the next page instead. Reported-by: Eli Cooper Cc: Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: hash - prevent using keyed hashes without setting key

2018-02-16T19:23:00Z

commit 9fa68f620041be04720d0cbfb1bd3ddfc6310b24 upstream. Currently, almost none of the keyed hash algorithms check whether a key has been set before proceeding. Some algorithms are okay with this and will effectively just use a key of all 0's or some other bogus default. However, others will severely break, as demonstrated using "hmac(sha3-512-generic)", the unkeyed use of which causes a kernel crash via a (potentially exploitable) stack buffer overflow. A while ago, this problem was solved for AF_ALG by pairing each hash transform with a 'has_key' bool. However, there are still other places in the kernel where userspace can specify an arbitrary hash algorithm by name, and the kernel uses it as unkeyed hash without checking whether it is really unkeyed. Examples of this include: - KEYCTL_DH_COMPUTE, via the KDF extension - dm-verity - dm-crypt, via the ESSIV support - dm-integrity, via the "internal hash" mode with no key given - drbd (Distributed Replicated Block Device) This bug is especially bad for KEYCTL_DH_COMPUTE as that requires no privileges to call. Fix the bug for all users by adding a flag CRYPTO_TFM_NEED_KEY to the ->crt_flags of each hash transform that indicates whether the transform still needs to be keyed or not. Then, make the hash init, import, and digest functions return -ENOKEY if the key is still needed. The new flag also replaces the 'has_key' bool which algif_hash was previously using, thereby simplifying the algif_hash implementation. Reported-by: syzbot Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: hash - introduce crypto_hash_alg_has_setkey()

2018-02-16T19:22:59Z

commit cd6ed77ad5d223dc6299fb58f62e0f5267f7e2ba upstream. Templates that use an shash spawn can use crypto_shash_alg_has_setkey() to determine whether the underlying algorithm requires a key or not. But there was no corresponding function for ahash spawns. Add it. Note that the new function actually has to support both shash and ahash algorithms, since the ahash API can be used with either. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman

crypto: hash - add crypto_(un)register_ahashes()

2017-08-22T06:54:52Z

There are already helpers to (un)register multiple normal and AEAD algos. Add one for ahashes too. Signed-off-by: Lars Persson Signed-off-by: Rabin Vincent Signed-off-by: Herbert Xu

crypto: ahash - Fix EINPROGRESS notification callback

2017-04-10T11:09:18Z

The ahash API modifies the request's callback function in order to clean up after itself in some corner cases (unaligned final and missing finup). When the request is complete ahash will restore the original callback and everything is fine. However, when the request gets an EBUSY on a full queue, an EINPROGRESS callback is made while the request is still ongoing. In this case the ahash API will incorrectly call its own callback. This patch fixes the problem by creating a temporary request object on the stack which is used to relay EINPROGRESS back to the original completion function. This patch also adds code to preserve the original flags value. Fixes: ab6bf4e5e5e4 ("crypto: hash - Fix the pointer voodoo in...") Cc: Reported-by: Sabrina Dubroca Tested-by: Sabrina Dubroca Signed-off-by: Herbert Xu

crypto: Replaced gcc specific attributes with macros from compiler.h

2017-01-12T16:24:39Z

Continuing from this commit: 52f5684c8e1e ("kernel: use macros from compiler.h instead of __attribute__((...))") I submitted 4 total patches. They are part of task I've taken up to increase compiler portability in the kernel. I've cleaned up the subsystems under /kernel /mm /block and /security, this patch targets /crypto. There is which provides macros for various gcc specific constructs. Eg: __weak for __attribute__((weak)). I've cleaned all instances of gcc specific attributes with the right macros for the crypto subsystem. I had to make one additional change into compiler-gcc.h for the case when one wants to use this: __attribute__((aligned) and not specify an alignment factor. From the gcc docs, this will result in the largest alignment for that data type on the target machine so I've named the macro __aligned_largest. Please advise if another name is more appropriate. Signed-off-by: Gideon Israel Dsouza Signed-off-by: Herbert Xu

crypto: ahash - Add padding in crypto_ahash_extsize

2016-07-01T15:45:03Z

The function crypto_ahash_extsize did not include padding when computing the tfm context size. This patch fixes this by using the generic crypto_alg_extsize helper. Signed-off-by: Herbert Xu

crypto: hash - Fix page length clamping in hash walk

2016-05-05T06:27:04Z

The crypto hash walk code is broken when supplied with an offset greater than or equal to PAGE_SIZE. This patch fixes it by adjusting walk->pg and walk->offset when this happens. Cc: Reported-by: Steffen Klassert Signed-off-by: Herbert Xu