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crypto: chacha20poly1305 - use crypto_grab_ahash() and simplify error paths 

Make the rfc7539 and rfc7539esp 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, and
by taking advantage of crypto_grab_*() now handling ERR_PTR() names.

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 19:58:59 -08:00 committed by Herbert Xu
parent 05b3bbb53a
commit c282586fc3
1 changed files with 27 additions and 57 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

84
crypto/chacha20poly1305.c
View File

@ -16,8 +16,6 @@
#include <linux/kernel.h>
#include <linux/module.h>
#include "internal.h"
struct chachapoly_instance_ctx {
struct crypto_skcipher_spawn chacha;
struct crypto_ahash_spawn poly;
@ -560,11 +558,9 @@ static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
struct crypto_attr_type *algt;
u32 mask;
struct aead_instance *inst;
struct skcipher_alg *chacha;
struct crypto_alg *poly;
struct hash_alg_common *poly_hash;
struct chachapoly_instance_ctx *ctx;
const char *chacha_name, *poly_name;
struct skcipher_alg *chacha;
struct hash_alg_common *poly;
int err;
if (ivsize > CHACHAPOLY_IV_SIZE)
@ -579,68 +575,51 @@ static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
mask = crypto_requires_sync(algt->type, algt->mask);
chacha_name = crypto_attr_alg_name(tb[1]);
if (IS_ERR(chacha_name))
return PTR_ERR(chacha_name);
poly_name = crypto_attr_alg_name(tb[2]);
if (IS_ERR(poly_name))
return PTR_ERR(poly_name);
poly = crypto_find_alg(poly_name, &crypto_ahash_type,
CRYPTO_ALG_TYPE_HASH,
CRYPTO_ALG_TYPE_AHASH_MASK | mask);
if (IS_ERR(poly))
return PTR_ERR(poly);
poly_hash = __crypto_hash_alg_common(poly);
err = -EINVAL;
if (poly_hash->digestsize != POLY1305_DIGEST_SIZE)
goto out_put_poly;
err = -ENOMEM;
inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
if (!inst)
goto out_put_poly;
return -ENOMEM;
ctx = aead_instance_ctx(inst);
ctx->saltlen = CHACHAPOLY_IV_SIZE - ivsize;
err = crypto_init_ahash_spawn(&ctx->poly, poly_hash,
aead_crypto_instance(inst));
if (err)
goto err_free_inst;
err = crypto_grab_skcipher(&ctx->chacha, aead_crypto_instance(inst),
chacha_name, 0, mask);
crypto_attr_alg_name(tb[1]), 0, mask);
if (err)
goto err_drop_poly;
goto err_free_inst;
chacha = crypto_spawn_skcipher_alg(&ctx->chacha);
err = crypto_grab_ahash(&ctx->poly, aead_crypto_instance(inst),
crypto_attr_alg_name(tb[2]), 0, mask);
if (err)
goto err_free_inst;
poly = crypto_spawn_ahash_alg(&ctx->poly);
err = -EINVAL;
if (poly->digestsize != POLY1305_DIGEST_SIZE)
goto err_free_inst;
/* Need 16-byte IV size, including Initial Block Counter value */
if (crypto_skcipher_alg_ivsize(chacha) != CHACHA_IV_SIZE)
goto out_drop_chacha;
goto err_free_inst;
/* Not a stream cipher? */
if (chacha->base.cra_blocksize != 1)
goto out_drop_chacha;
goto err_free_inst;
err = -ENAMETOOLONG;
if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
"%s(%s,%s)", name, chacha->base.cra_name,
poly->cra_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_chacha;
poly->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
"%s(%s,%s)", name, chacha->base.cra_driver_name,
poly->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto out_drop_chacha;
poly->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
goto err_free_inst;
inst->alg.base.cra_flags = (chacha->base.cra_flags | poly->cra_flags) &
CRYPTO_ALG_ASYNC;
inst->alg.base.cra_flags = (chacha->base.cra_flags |
poly->base.cra_flags) & CRYPTO_ALG_ASYNC;
inst->alg.base.cra_priority = (chacha->base.cra_priority +
poly->cra_priority) / 2;
poly->base.cra_priority) / 2;
inst->alg.base.cra_blocksize = 1;
inst->alg.base.cra_alignmask = chacha->base.cra_alignmask |
poly->cra_alignmask;
poly->base.cra_alignmask;
inst->alg.base.cra_ctxsize = sizeof(struct chachapoly_ctx) +
ctx->saltlen;
inst->alg.ivsize = ivsize;
@ -656,20 +635,11 @@ static int chachapoly_create(struct crypto_template *tmpl, struct rtattr **tb,
inst->free = chachapoly_free;
err = aead_register_instance(tmpl, inst);
if (err)
goto out_drop_chacha;
out_put_poly:
crypto_mod_put(poly);
return err;
out_drop_chacha:
crypto_drop_skcipher(&ctx->chacha);
err_drop_poly:
crypto_drop_ahash(&ctx->poly);
if (err) {
err_free_inst:
kfree(inst);
goto out_put_poly;
chachapoly_free(inst);
}
return err;
}
static int rfc7539_create(struct crypto_template *tmpl, struct rtattr **tb)