crypto: shash - require neither or both ->export() and ->import()
Prevent registering shash algorithms that implement ->export() but not
->import(), or ->import() but not ->export(). Such cases don't make
sense and could confuse the check that shash_prepare_alg() does for just
->export().
I don't believe this affects any existing algorithms; this is just
preventing future mistakes.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/shash.c b/crypto/shash.c
index 40311cc..2bffdec 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -472,6 +472,9 @@ static int shash_prepare_alg(struct shash_alg *alg)
alg->statesize > HASH_MAX_STATESIZE)
return -EINVAL;
+ if ((alg->export && !alg->import) || (alg->import && !alg->export))
+ return -EINVAL;
+
base->cra_type = &crypto_shash_type;
base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
