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>
This commit is contained in:
Eric Biggers 2020-01-02 19:58:58 -08:00 committed by Herbert Xu
parent ab6ffd360d
commit 05b3bbb53a

View File

@ -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 skcipher_alg *ctr;
struct crypto_alg *mac_alg;
struct hash_alg_common *mac;
struct ccm_instance_ctx *ictx;
struct skcipher_alg *ctr;
struct hash_alg_common *mac;
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);
inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
if (!inst)
return -ENOMEM;
ictx = aead_instance_ctx(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);
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;
ictx = aead_instance_ctx(inst);
err = crypto_init_ahash_spawn(&ictx->mac, mac,
aead_crypto_instance(inst));
if (err)
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)