Commit ab6ffd36 authored by Eric Biggers's avatar Eric Biggers Committed by Herbert Xu
Browse files

crypto: gcm - use crypto_grab_ahash() and simplify error paths 



Make the gcm and gcm_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 37073882

crypto/gcm.c

+16 −36
Original line number Diff line number Diff line
@@ -13,7 +13,6 @@ 
#include <crypto/scatterwalk.h>

#include <crypto/gcm.h>

#include <crypto/hash.h>

#include "internal.h"

#include <linux/err.h>

#include <linux/init.h>

#include <linux/kernel.h>
@@ -582,10 +581,9 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl, 
	struct crypto_attr_type *algt;

	u32 mask;

	struct aead_instance *inst;

	struct gcm_instance_ctx *ctx;

	struct skcipher_alg *ctr;

	struct crypto_alg *ghash_alg;

	struct hash_alg_common *ghash;

	struct gcm_instance_ctx *ctx;

	int err;



	algt = crypto_get_attr_type(tb);
@@ -597,35 +595,26 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl, 


	mask = crypto_requires_sync(algt->type, algt->mask);



	ghash_alg = crypto_find_alg(ghash_name, &crypto_ahash_type,

				    CRYPTO_ALG_TYPE_HASH,

				    CRYPTO_ALG_TYPE_AHASH_MASK | mask);

	if (IS_ERR(ghash_alg))

		return PTR_ERR(ghash_alg);



	ghash = __crypto_hash_alg_common(ghash_alg);



	err = -ENOMEM;

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

	if (!inst)

		goto out_put_ghash;



		return -ENOMEM;

	ctx = aead_instance_ctx(inst);

	err = crypto_init_ahash_spawn(&ctx->ghash, ghash,

				      aead_crypto_instance(inst));



	err = crypto_grab_ahash(&ctx->ghash, aead_crypto_instance(inst),

				ghash_name, 0, mask);

	if (err)

		goto err_free_inst;

	ghash = crypto_spawn_ahash_alg(&ctx->ghash);



	err = -EINVAL;

	if (strcmp(ghash->base.cra_name, "ghash") != 0 ||

	    ghash->digestsize != 16)

		goto err_drop_ghash;

		goto err_free_inst;



	err = crypto_grab_skcipher(&ctx->ctr, aead_crypto_instance(inst),

				   ctr_name, 0, mask);

	if (err)

		goto err_drop_ghash;



		goto err_free_inst;

	ctr = crypto_spawn_skcipher_alg(&ctx->ctr);



	/* The skcipher algorithm must be CTR mode, using 16-byte blocks. */
@@ -633,18 +622,18 @@ static int crypto_gcm_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 out_put_ctr;

		goto err_free_inst;



	err = -ENAMETOOLONG;

	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,

		     "gcm(%s", ctr->base.cra_name + 4) >= CRYPTO_MAX_ALG_NAME)

		goto out_put_ctr;

		goto err_free_inst;



	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,

		     "gcm_base(%s,%s)", ctr->base.cra_driver_name,

		     ghash_alg->cra_driver_name) >=

		     ghash->base.cra_driver_name) >=

	    CRYPTO_MAX_ALG_NAME)

		goto out_put_ctr;

		goto err_free_inst;



	inst->alg.base.cra_flags = (ghash->base.cra_flags |

				    ctr->base.cra_flags) & CRYPTO_ALG_ASYNC;
@@ -667,20 +656,11 @@ static int crypto_gcm_create_common(struct crypto_template *tmpl, 
	inst->free = crypto_gcm_free;



	err = aead_register_instance(tmpl, inst);

	if (err)

		goto out_put_ctr;



out_put_ghash:

	crypto_mod_put(ghash_alg);

	return err;



out_put_ctr:

	crypto_drop_skcipher(&ctx->ctr);

err_drop_ghash:

	crypto_drop_ahash(&ctx->ghash);

	if (err) {

err_free_inst:

	kfree(inst);

	goto out_put_ghash;

		crypto_gcm_free(inst);

	}

	return err;

}



static int crypto_gcm_create(struct crypto_template *tmpl, struct rtattr **tb)