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@xxxxxxxxxxxxxxxxxxx>
---
crypto/ahash.c | 51 ++++++++++++++++++++++++++++++++++++++++
crypto/hash.h | 4 +++
crypto/shash.c | 52 +++++++++++++++++++++++++++++++++++++++++
include/crypto/hash.h | 8 ++++++
include/crypto/internal/hash.h | 2 -
5 files changed, 115 insertions(+), 2 deletions(-)
diff --git a/crypto/ahash.c b/crypto/ahash.c
index 2d858d7fd1bb..b8a607928e72 100644
--- a/crypto/ahash.c
+++ b/crypto/ahash.c
@@ -543,6 +543,57 @@ int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
}
EXPORT_SYMBOL_GPL(crypto_has_ahash);
+struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *hash)
+{
+ struct hash_alg_common *halg = crypto_hash_alg_common(hash);
+ struct crypto_tfm *tfm = crypto_ahash_tfm(hash);
+ struct crypto_ahash *nhash;
+ struct ahash_alg *alg;
+ int err;
+
+ if (!crypto_hash_alg_has_setkey(halg)) {
+ tfm = crypto_tfm_get(tfm);
+ if (IS_ERR(tfm))
+ return ERR_CAST(tfm);
+
+ return hash;
+ }
+
+ nhash = crypto_clone_tfm(&crypto_ahash_type, tfm);
+
+ if (IS_ERR(nhash))
+ return nhash;
+
+ nhash->init = hash->init;
+ nhash->update = hash->update;
+ nhash->final = hash->final;
+ nhash->finup = hash->finup;
+ nhash->digest = hash->digest;
+ nhash->export = hash->export;
+ nhash->import = hash->import;
+ nhash->setkey = hash->setkey;
+ nhash->reqsize = hash->reqsize;
+
+ if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
+ return crypto_clone_shash_ops_async(nhash, hash);
+
+ err = -ENOSYS;
+ alg = crypto_ahash_alg(hash);
+ if (!alg->clone_tfm)
+ goto out_free_nhash;
+
+ err = alg->clone_tfm(nhash, hash);
+ if (err)
+ goto out_free_nhash;
+
+ return nhash;
+
+out_free_nhash:
+ crypto_free_ahash(nhash);
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(crypto_clone_ahash);
+
static int ahash_prepare_alg(struct ahash_alg *alg)
{
struct crypto_alg *base = &alg->halg.base;
diff --git a/crypto/hash.h b/crypto/hash.h
index 57b28a986d69..7e6c1a948692 100644
--- a/crypto/hash.h
+++ b/crypto/hash.h
@@ -31,6 +31,10 @@ static inline int crypto_hash_report_stat(struct sk_buff *skb,
return nla_put(skb, CRYPTOCFGA_STAT_HASH, sizeof(rhash), &rhash);
}
+int crypto_init_shash_ops_async(struct crypto_tfm *tfm);
+struct crypto_ahash *crypto_clone_shash_ops_async(struct crypto_ahash *nhash,
+ struct crypto_ahash *hash);
+
int hash_prepare_alg(struct hash_alg_common *alg);
#endif /* _LOCAL_CRYPTO_HASH_H */
diff --git a/crypto/shash.c b/crypto/shash.c
index 4cefa614dbbd..5845b7d59b2f 100644
--- a/crypto/shash.c
+++ b/crypto/shash.c
@@ -445,6 +445,24 @@ int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
return 0;
}
+struct crypto_ahash *crypto_clone_shash_ops_async(struct crypto_ahash *nhash,
+ struct crypto_ahash *hash)
+{
+ struct crypto_shash **nctx = crypto_ahash_ctx(nhash);
+ struct crypto_shash **ctx = crypto_ahash_ctx(hash);
+ struct crypto_shash *shash;
+
+ shash = crypto_clone_shash(*ctx);
+ if (IS_ERR(shash)) {
+ crypto_free_ahash(nhash);
+ return ERR_CAST(shash);
+ }
+
+ *nctx = shash;
+
+ return nhash;
+}
+
static void crypto_shash_exit_tfm(struct crypto_tfm *tfm)
{
struct crypto_shash *hash = __crypto_shash_cast(tfm);
@@ -564,6 +582,40 @@ int crypto_has_shash(const char *alg_name, u32 type, u32 mask)
}
EXPORT_SYMBOL_GPL(crypto_has_shash);
+struct crypto_shash *crypto_clone_shash(struct crypto_shash *hash)
+{
+ struct crypto_tfm *tfm = crypto_shash_tfm(hash);
+ struct shash_alg *alg = crypto_shash_alg(hash);
+ struct crypto_shash *nhash;
+ int err;
+
+ if (!crypto_shash_alg_has_setkey(alg)) {
+ tfm = crypto_tfm_get(tfm);
+ if (IS_ERR(tfm))
+ return ERR_CAST(tfm);
+
+ return hash;
+ }
+
+ if (!alg->clone_tfm)
+ return ERR_PTR(-ENOSYS);
+
+ nhash = crypto_clone_tfm(&crypto_shash_type, tfm);
+ if (IS_ERR(nhash))
+ return nhash;
+
+ nhash->descsize = hash->descsize;
+
+ err = alg->clone_tfm(nhash, hash);
+ if (err) {
+ crypto_free_shash(nhash);
+ return ERR_PTR(err);
+ }
+
+ return nhash;
+}
+EXPORT_SYMBOL_GPL(crypto_clone_shash);
+
int hash_prepare_alg(struct hash_alg_common *alg)
{
struct crypto_istat_hash *istat = hash_get_stat(alg);
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));
