crypto: hash - Add crypto_clone_ahash/shash

This patch adds the helpers crypto_clone_ahash and crypto_clone_shash.
They are the hash-specific counterparts of crypto_clone_tfm.

This allows code paths that cannot otherwise allocate a hash tfm
object to do so.  Once a new tfm has been obtained its key could
then be changed without impacting other users.

Note that only algorithms that implement clone_tfm can be cloned.
However, all keyless hashes can be cloned by simply reusing the
tfm object.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 8 insertions, 2 deletions

diff --git a/include/crypto/hash.h b/include/crypto/hash.h
index 3a04e601ad6a..e69542d86a2b 100644
--- a/include/crypto/hash.h
+++ b/include/crypto/hash.h
@@ -152,6 +152,7 @@ struct ahash_request {
  * @exit_tfm: Deinitialize the cryptographic transformation object.
  *	      This is a counterpart to @init_tfm, used to remove
  *	      various changes set in @init_tfm.
+ * @clone_tfm: Copy transform into new object, may allocate memory.
  * @halg: see struct hash_alg_common
  */
 struct ahash_alg {
@@ -166,6 +167,7 @@ struct ahash_alg {
 		      unsigned int keylen);
 	int (*init_tfm)(struct crypto_ahash *tfm);
 	void (*exit_tfm)(struct crypto_ahash *tfm);
+	int (*clone_tfm)(struct crypto_ahash *dst, struct crypto_ahash *src);
 
 	struct hash_alg_common halg;
 };
@@ -209,6 +211,7 @@ struct shash_desc {
  * @exit_tfm: Deinitialize the cryptographic transformation object.
  *	      This is a counterpart to @init_tfm, used to remove
  *	      various changes set in @init_tfm.
+ * @clone_tfm: Copy transform into new object, may allocate memory.
  * @digestsize: see struct ahash_alg
  * @statesize: see struct ahash_alg
  * @descsize: Size of the operational state for the message digest. This state
@@ -234,6 +237,7 @@ struct shash_alg {
 		      unsigned int keylen);
 	int (*init_tfm)(struct crypto_shash *tfm);
 	void (*exit_tfm)(struct crypto_shash *tfm);
+	int (*clone_tfm)(struct crypto_shash *dst, struct crypto_shash *src);
 
 	unsigned int descsize;
 
@@ -297,6 +301,8 @@ static inline struct crypto_ahash *__crypto_ahash_cast(struct crypto_tfm *tfm)
 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
 					u32 mask);
 
+struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *tfm);
+
 static inline struct crypto_tfm *crypto_ahash_tfm(struct crypto_ahash *tfm)
 {
 	return &tfm->base;
@@ -761,6 +767,8 @@ 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);
 
+struct crypto_shash *crypto_clone_shash(struct crypto_shash *tfm);
+
 int crypto_has_shash(const char *alg_name, u32 type, u32 mask);
 
 static inline struct crypto_tfm *crypto_shash_tfm(struct crypto_shash *tfm)
diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index 0b259dbb97af..37edf3f4e8af 100644
--- a/include/crypto/internal/hash.h
+++ b/include/crypto/internal/hash.h
@@ -133,8 +133,6 @@ int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc);
 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc);
 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc);
 
-int crypto_init_shash_ops_async(struct crypto_tfm *tfm);
-
 static inline void *crypto_ahash_ctx(struct crypto_ahash *tfm)
 {
 	return crypto_tfm_ctx(crypto_ahash_tfm(tfm));