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>

diff --git a/crypto/hmac.c b/crypto/hmac.c
index 377f07733e2fa86c3f5476a951909cd3ca40a40d..685e49953605656a4b8cffd7014da1dfc8b179c5 100644 (file)
--- a/crypto/hmac.c
+++ b/crypto/hmac.c
@@ -138,12 +138,11 @@ static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
               crypto_shash_finup(desc, out, ds, out);
 }
 
-static int hmac_init_tfm(struct crypto_tfm *tfm)
+static int hmac_init_tfm(struct crypto_shash *parent)
 {
-       struct crypto_shash *parent = __crypto_shash_cast(tfm);
        struct crypto_shash *hash;
-       struct crypto_instance *inst = (void *)tfm->__crt_alg;
-       struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
+       struct shash_instance *inst = shash_alg_instance(parent);
+       struct crypto_shash_spawn *spawn = shash_instance_ctx(inst);
        struct hmac_ctx *ctx = hmac_ctx(parent);
 
        hash = crypto_spawn_shash(spawn);
@@ -152,18 +151,14 @@ static int hmac_init_tfm(struct crypto_tfm *tfm)
 
        parent->descsize = sizeof(struct shash_desc) +
                           crypto_shash_descsize(hash);
-       if (WARN_ON(parent->descsize > HASH_MAX_DESCSIZE)) {
-               crypto_free_shash(hash);
-               return -EINVAL;
-       }
 
        ctx->hash = hash;
        return 0;
 }
 
-static void hmac_exit_tfm(struct crypto_tfm *tfm)
+static void hmac_exit_tfm(struct crypto_shash *parent)
 {
-       struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
+       struct hmac_ctx *ctx = hmac_ctx(parent);
        crypto_free_shash(ctx->hash);
 }
 
@@ -217,9 +212,6 @@ static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
        inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
                                     ALIGN(ss * 2, crypto_tfm_ctx_alignment());
 
-       inst->alg.base.cra_init = hmac_init_tfm;
-       inst->alg.base.cra_exit = hmac_exit_tfm;
-
        inst->alg.init = hmac_init;
        inst->alg.update = hmac_update;
        inst->alg.final = hmac_final;
@@ -227,6 +219,8 @@ static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
        inst->alg.export = hmac_export;
        inst->alg.import = hmac_import;
        inst->alg.setkey = hmac_setkey;
+       inst->alg.init_tfm = hmac_init_tfm;
+       inst->alg.exit_tfm = hmac_exit_tfm;
 
        err = shash_register_instance(tmpl, inst);
        if (err) {

diff --git a/include/crypto/internal/hash.h b/include/crypto/internal/hash.h
index f68dab38f160c17ef701db49ea1cbf541ed353f4..cf8d7f99c93d8a12360e3fdd74ea881269a6e00a 100644 (file)
--- 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));