crypto: add crypto_has_shash()

Add helper function to determine if a given synchronous hash is supported.
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

crypto/shash.c

@@ -521,6 +521,12 @@ struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 }
 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
 
+int crypto_has_shash(const char *alg_name, u32 type, u32 mask)
+{
+	return crypto_type_has_alg(alg_name, &crypto_shash_type, type, mask);
+}
+EXPORT_SYMBOL_GPL(crypto_has_shash);
+
 static int shash_prepare_alg(struct shash_alg *alg)
 {
 	struct crypto_alg *base = &alg->base;

include/crypto/hash.h

@@ -718,6 +718,8 @@ static inline void ahash_request_set_crypt(struct ahash_request *req,
 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
 					u32 mask);
 
+int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
+
 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
 {
 	return &tfm->base;