crypto: rsa-pkcs1pad - simplify error handling in pkcs1pad_create()

Simplify the error handling in pkcs1pad_create() by taking advantage of
crypto_grab_akcipher() now handling an ERR_PTR() name and by taking
advantage of crypto_drop_akcipher() now accepting (as a no-op) a spawn
that hasn't been grabbed yet.

While we're at it, also simplify the way the hash_name optional argument
is handled.  We only need to check whether it's present in one place,
and we can just assign directly to ctx->digest_info.

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 20:59:23 -08:00 committed by Herbert Xu
parent 07b24c7c08
commit 0708bb4353

View file

@ -596,14 +596,11 @@ static void pkcs1pad_free(struct akcipher_instance *inst)
static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
{
const struct rsa_asn1_template *digest_info;
struct crypto_attr_type *algt;
u32 mask;
struct akcipher_instance *inst;
struct pkcs1pad_inst_ctx *ctx;
struct crypto_akcipher_spawn *spawn;
struct akcipher_alg *rsa_alg;
const char *rsa_alg_name;
const char *hash_name;
int err;
@ -616,60 +613,49 @@ static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
mask = crypto_requires_sync(algt->type, algt->mask);
rsa_alg_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(rsa_alg_name))
return PTR_ERR(rsa_alg_name);
hash_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(hash_name))
hash_name = NULL;
if (hash_name) {
digest_info = rsa_lookup_asn1(hash_name);
if (!digest_info)
return -EINVAL;
} else
digest_info = NULL;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
return -ENOMEM;
ctx = akcipher_instance_ctx(inst);
spawn = &ctx->spawn;
ctx->digest_info = digest_info;
err = crypto_grab_akcipher(spawn, akcipher_crypto_instance(inst),
rsa_alg_name, 0, mask);
err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
crypto_attr_alg_name(tb[1]), 0, mask);
if (err)
goto out_free_inst;
goto err_free_inst;
rsa_alg = crypto_spawn_akcipher_alg(spawn);
rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
err = -ENAMETOOLONG;
if (!hash_name) {
hash_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(hash_name)) {
if (snprintf(inst->alg.base.cra_name,
CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
goto err_free_inst;
if (snprintf(inst->alg.base.cra_driver_name,
CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
rsa_alg->base.cra_driver_name) >=
CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
goto err_free_inst;
} else {
ctx->digest_info = rsa_lookup_asn1(hash_name);
if (!ctx->digest_info) {
err = -EINVAL;
goto err_free_inst;
}
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
hash_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
goto err_free_inst;
if (snprintf(inst->alg.base.cra_driver_name,
CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
rsa_alg->base.cra_driver_name,
hash_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_alg;
goto err_free_inst;
}
inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
@ -691,15 +677,10 @@ static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
inst->free = pkcs1pad_free;
err = akcipher_register_instance(tmpl, inst);
if (err)
goto out_drop_alg;
return 0;
out_drop_alg:
crypto_drop_akcipher(spawn);
out_free_inst:
kfree(inst);
if (err) {
err_free_inst:
pkcs1pad_free(inst);
}
return err;
}