crypto: ctr - simplify error handling in crypto_rfc3686_create()

Simplify the error handling in crypto_rfc3686_create() by taking
advantage of crypto_grab_skcipher() now handling an ERR_PTR() name and
by taking advantage of crypto_drop_skcipher() now accepting (as a no-op)
a spawn that hasn't been grabbed 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 2020-02-25 20:59:16 -08:00 committed by Herbert Xu
parent b8c0d74a70
commit a108dfcff8
1 changed files with 9 additions and 20 deletions

View File

@ -260,7 +260,6 @@ static int crypto_rfc3686_create(struct crypto_template *tmpl,
struct skcipher_instance *inst; struct skcipher_instance *inst;
struct skcipher_alg *alg; struct skcipher_alg *alg;
struct crypto_skcipher_spawn *spawn; struct crypto_skcipher_spawn *spawn;
const char *cipher_name;
u32 mask; u32 mask;
int err; int err;
@ -272,10 +271,6 @@ static int crypto_rfc3686_create(struct crypto_template *tmpl,
if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask) if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
return -EINVAL; return -EINVAL;
cipher_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(cipher_name))
return PTR_ERR(cipher_name);
inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
if (!inst) if (!inst)
return -ENOMEM; return -ENOMEM;
@ -287,7 +282,7 @@ static int crypto_rfc3686_create(struct crypto_template *tmpl,
spawn = skcipher_instance_ctx(inst); spawn = skcipher_instance_ctx(inst);
err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst), err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
cipher_name, 0, mask); crypto_attr_alg_name(tb[1]), 0, mask);
if (err) if (err)
goto err_free_inst; goto err_free_inst;
@ -296,20 +291,20 @@ static int crypto_rfc3686_create(struct crypto_template *tmpl,
/* We only support 16-byte blocks. */ /* We only support 16-byte blocks. */
err = -EINVAL; err = -EINVAL;
if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE) if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
goto err_drop_spawn; goto err_free_inst;
/* Not a stream cipher? */ /* Not a stream cipher? */
if (alg->base.cra_blocksize != 1) if (alg->base.cra_blocksize != 1)
goto err_drop_spawn; goto err_free_inst;
err = -ENAMETOOLONG; err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME) "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
goto err_drop_spawn; goto err_free_inst;
if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"rfc3686(%s)", alg->base.cra_driver_name) >= "rfc3686(%s)", alg->base.cra_driver_name) >=
CRYPTO_MAX_ALG_NAME) CRYPTO_MAX_ALG_NAME)
goto err_drop_spawn; goto err_free_inst;
inst->alg.base.cra_priority = alg->base.cra_priority; inst->alg.base.cra_priority = alg->base.cra_priority;
inst->alg.base.cra_blocksize = 1; inst->alg.base.cra_blocksize = 1;
@ -336,17 +331,11 @@ static int crypto_rfc3686_create(struct crypto_template *tmpl,
inst->free = crypto_rfc3686_free; inst->free = crypto_rfc3686_free;
err = skcipher_register_instance(tmpl, inst); err = skcipher_register_instance(tmpl, inst);
if (err) if (err) {
goto err_drop_spawn;
out:
return err;
err_drop_spawn:
crypto_drop_skcipher(spawn);
err_free_inst: err_free_inst:
kfree(inst); crypto_rfc3686_free(inst);
goto out; }
return err;
} }
static struct crypto_template crypto_ctr_tmpls[] = { static struct crypto_template crypto_ctr_tmpls[] = {