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

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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: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers 2020-01-02 19:58:57 -08:00 committed by Herbert Xu
parent 370738824b
commit ab6ffd360d
1 changed files with 17 additions and 37 deletions
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54
crypto/gcm.c
View File

@ -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 skcipher_alg *ctr;
struct crypto_alg *ghash_alg;
struct hash_alg_common *ghash;
struct gcm_instance_ctx *ctx;
struct skcipher_alg *ctr;
struct hash_alg_common *ghash;
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)