crypto: cbcmac - use crypto_grab_cipher() and simplify error paths

Make the cbcmac template use the new function crypto_grab_cipher() to
initialize its cipher spawn.

This is needed to make all spawns be initialized in a consistent way.

This required making cbcmac_create() allocate the instance directly
rather than use shash_alloc_instance().

Also simplify the error handling by taking advantage of crypto_drop_*()
now accepting (as a no-op) spawns that haven't been initialized yet, and
by taking advantage of crypto_grab_*() now handling ERR_PTR() names.

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

diff --git a/crypto/ccm.c b/crypto/ccm.c
index a9fb46f..411c397 100644 (file)
--- a/crypto/ccm.c
+++ b/crypto/ccm.c
@@ -887,6 +887,7 @@ static void cbcmac_exit_tfm(struct crypto_tfm *tfm)
 static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
 {
        struct shash_instance *inst;
+       struct crypto_cipher_spawn *spawn;
        struct crypto_alg *alg;
        int err;
 
@@ -894,21 +895,20 @@ static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
        if (err)
                return err;
 
-       alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
-                                 CRYPTO_ALG_TYPE_MASK);
-       if (IS_ERR(alg))
-               return PTR_ERR(alg);
+       inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+       if (!inst)
+               return -ENOMEM;
+       spawn = shash_instance_ctx(inst);
 
-       inst = shash_alloc_instance("cbcmac", alg);
-       err = PTR_ERR(inst);
-       if (IS_ERR(inst))
-               goto out_put_alg;
+       err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),
+                                crypto_attr_alg_name(tb[1]), 0, 0);
+       if (err)
+               goto err_free_inst;
+       alg = crypto_spawn_cipher_alg(spawn);
 
-       err = crypto_init_spawn(shash_instance_ctx(inst), alg,
-                               shash_crypto_instance(inst),
-                               CRYPTO_ALG_TYPE_MASK);
+       err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);
        if (err)
-               goto out_free_inst;
+               goto err_free_inst;
 
        inst->alg.base.cra_priority = alg->cra_priority;
        inst->alg.base.cra_blocksize = 1;
@@ -928,13 +928,10 @@ static int cbcmac_create(struct crypto_template *tmpl, struct rtattr **tb)
        inst->alg.setkey = crypto_cbcmac_digest_setkey;
 
        err = shash_register_instance(tmpl, inst);
-
-out_free_inst:
-       if (err)
+       if (err) {
+err_free_inst:
                shash_free_instance(shash_crypto_instance(inst));
-
-out_put_alg:
-       crypto_mod_put(alg);
+       }
        return err;
 }