Commit 39e7a283 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: hmac - use crypto_grab_shash() and simplify error paths 



Make the hmac template use the new function crypto_grab_shash() to
initialize its shash spawn.

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

This required making hmac_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: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 218c5035

crypto/hmac.c

+16 −17
Original line number Diff line number Diff line
@@ -165,6 +165,7 @@ static void hmac_exit_tfm(struct crypto_shash *parent) 
static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)

{

	struct shash_instance *inst;

	struct crypto_shash_spawn *spawn;

	struct crypto_alg *alg;

	struct shash_alg *salg;

	int err;
@@ -175,31 +176,32 @@ static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb) 
	if (err)

		return err;



	salg = shash_attr_alg(tb[1], 0, 0);

	if (IS_ERR(salg))

		return PTR_ERR(salg);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);

	if (!inst)

		return -ENOMEM;

	spawn = shash_instance_ctx(inst);



	err = crypto_grab_shash(spawn, shash_crypto_instance(inst),

				crypto_attr_alg_name(tb[1]), 0, 0);

	if (err)

		goto err_free_inst;

	salg = crypto_spawn_shash_alg(spawn);

	alg = &salg->base;



	/* The underlying hash algorithm must not require a key */

	err = -EINVAL;

	if (crypto_shash_alg_needs_key(salg))

		goto out_put_alg;

		goto err_free_inst;



	ds = salg->digestsize;

	ss = salg->statesize;

	if (ds > alg->cra_blocksize ||

	    ss < alg->cra_blocksize)

		goto out_put_alg;

		goto err_free_inst;



	inst = shash_alloc_instance("hmac", alg);

	err = PTR_ERR(inst);

	if (IS_ERR(inst))

		goto out_put_alg;



	err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,

				      shash_crypto_instance(inst));

	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 = alg->cra_blocksize;
@@ -224,12 +226,9 @@ static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb) 


	err = shash_register_instance(tmpl, inst);

	if (err) {

out_free_inst:

err_free_inst:

		shash_free_instance(shash_crypto_instance(inst));

	}



out_put_alg:

	crypto_mod_put(alg);

	return err;

}