crypto: hmac - Use init_tfm/exit_tfm interface

This patch switches hmac over to the new init_tfm/exit_tfm interface
as opposed to cra_init/cra_exit.  This way the shash API can make
sure that descsize does not exceed the maximum.

This patch also adds the API helper shash_alg_instance.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index f68dab38f160..cf8d7f99c93d 100644
--- a/include/crypto/internal/hash.h
+++ b/include/crypto/internal/hash.h
@@ -220,6 +220,12 @@ static inline struct shash_instance *shash_instance(
 			    struct shash_instance, alg);
 }
 
+static inline struct shash_instance *shash_alg_instance(
+	struct crypto_shash *shash)
+{
+	return shash_instance(crypto_tfm_alg_instance(&shash->base));
+}
+
 static inline void *shash_instance_ctx(struct shash_instance *inst)
 {
 	return crypto_instance_ctx(shash_crypto_instance(inst));