Commit 05b3bbb5 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

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: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent ab6ffd36

crypto/ccm.c

+20 −41
Original line number Diff line number Diff line
@@ -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)