crypto: ccm - use crypto_grab_ahash() and simplify error paths

Make the ccm and ccm_base templates use the new function
crypto_grab_ahash() to initialize their ahash spawn.

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

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

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 48766e81b93355268fe8e59274ec357a667486c9..a9fb46f22eaaff10a1c95ea4b636daef2b089843 100644 (file)
--- a/crypto/ccm.c
+++ b/crypto/ccm.c
@@ -15,8 +15,6 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 
-#include "internal.h"
-
 struct ccm_instance_ctx {
        struct crypto_skcipher_spawn ctr;
        struct crypto_ahash_spawn mac;
@@ -452,10 +450,9 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl,
        struct crypto_attr_type *algt;
        u32 mask;
        struct aead_instance *inst;
+       struct ccm_instance_ctx *ictx;
        struct skcipher_alg *ctr;
-       struct crypto_alg *mac_alg;
        struct hash_alg_common *mac;
-       struct ccm_instance_ctx *ictx;
        int err;
 
        algt = crypto_get_attr_type(tb);
@@ -467,35 +464,26 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl,
 
        mask = crypto_requires_sync(algt->type, algt->mask);
 
-       mac_alg = crypto_find_alg(mac_name, &crypto_ahash_type,
-                                 CRYPTO_ALG_TYPE_HASH,
-                                 CRYPTO_ALG_TYPE_AHASH_MASK |
-                                 CRYPTO_ALG_ASYNC);
-       if (IS_ERR(mac_alg))
-               return PTR_ERR(mac_alg);
-
-       mac = __crypto_hash_alg_common(mac_alg);
-       err = -EINVAL;
-       if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
-           mac->digestsize != 16)
-               goto out_put_mac;
-
        inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
-       err = -ENOMEM;
        if (!inst)
-               goto out_put_mac;
-
+               return -ENOMEM;
        ictx = aead_instance_ctx(inst);
-       err = crypto_init_ahash_spawn(&ictx->mac, mac,
-                                     aead_crypto_instance(inst));
+
+       err = crypto_grab_ahash(&ictx->mac, aead_crypto_instance(inst),
+                               mac_name, 0, CRYPTO_ALG_ASYNC);
        if (err)
                goto err_free_inst;
+       mac = crypto_spawn_ahash_alg(&ictx->mac);
+
+       err = -EINVAL;
+       if (strncmp(mac->base.cra_name, "cbcmac(", 7) != 0 ||
+           mac->digestsize != 16)
+               goto err_free_inst;
 
        err = crypto_grab_skcipher(&ictx->ctr, aead_crypto_instance(inst),
                                   ctr_name, 0, mask);
        if (err)
-               goto err_drop_mac;
-
+               goto err_free_inst;
        ctr = crypto_spawn_skcipher_alg(&ictx->ctr);
 
        /* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
@@ -503,21 +491,21 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl,
        if (strncmp(ctr->base.cra_name, "ctr(", 4) != 0 ||
            crypto_skcipher_alg_ivsize(ctr) != 16 ||
            ctr->base.cra_blocksize != 1)
-               goto err_drop_ctr;
+               goto err_free_inst;
 
        /* ctr and cbcmac must use the same underlying block cipher. */
        if (strcmp(ctr->base.cra_name + 4, mac->base.cra_name + 7) != 0)
-               goto err_drop_ctr;
+               goto err_free_inst;
 
        err = -ENAMETOOLONG;
        if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
                     "ccm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)
-               goto err_drop_ctr;
+               goto err_free_inst;
 
        if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
                     "ccm_base(%s,%s)", ctr->base.cra_driver_name,
                     mac->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
-               goto err_drop_ctr;
+               goto err_free_inst;
 
        inst->alg.base.cra_flags = ctr->base.cra_flags & CRYPTO_ALG_ASYNC;
        inst->alg.base.cra_priority = (mac->base.cra_priority +
@@ -539,20 +527,11 @@ static int crypto_ccm_create_common(struct crypto_template *tmpl,
        inst->free = crypto_ccm_free;
 
        err = aead_register_instance(tmpl, inst);
-       if (err)
-               goto err_drop_ctr;
-
-out_put_mac:
-       crypto_mod_put(mac_alg);
-       return err;
-
-err_drop_ctr:
-       crypto_drop_skcipher(&ictx->ctr);
-err_drop_mac:
-       crypto_drop_ahash(&ictx->mac);
+       if (err) {
 err_free_inst:
-       kfree(inst);
-       goto out_put_mac;
+               crypto_ccm_free(inst);
+       }
+       return err;
 }
 
 static int crypto_ccm_create(struct crypto_template *tmpl, struct rtattr **tb)