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crypto: drbg - move to generic async completion

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DRBG is starting an async. crypto op and waiting for it complete.
Move it over to generic code doing the same.

The code now also passes CRYPTO_TFM_REQ_MAY_SLEEP flag indicating
crypto request memory allocation may use GFP_KERNEL which should
be perfectly fine as the code is obviously sleeping for the
completion of the request any way.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Gilad Ben-Yossef 2017-10-18 08:00:41 +01:00 committed by Herbert Xu
parent 0ca2a04ac3
commit 85a2dea4bd
2 changed files with 10 additions and 29 deletions
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36
crypto/drbg.c
View File

@ -1651,16 +1651,6 @@ static int drbg_fini_sym_kernel(struct drbg_state *drbg)
return 0;
}
static void drbg_skcipher_cb(struct crypto_async_request *req, int error)
{
struct drbg_state *drbg = req->data;
if (error == -EINPROGRESS)
return;
drbg->ctr_async_err = error;
complete(&drbg->ctr_completion);
}
static int drbg_init_sym_kernel(struct drbg_state *drbg)
{
struct crypto_cipher *tfm;
@ -1691,7 +1681,7 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg)
return PTR_ERR(sk_tfm);
}
drbg->ctr_handle = sk_tfm;
init_completion(&drbg->ctr_completion);
crypto_init_wait(&drbg->ctr_wait);
req = skcipher_request_alloc(sk_tfm, GFP_KERNEL);
if (!req) {
@ -1700,8 +1690,9 @@ static int drbg_init_sym_kernel(struct drbg_state *drbg)
return -ENOMEM;
}
drbg->ctr_req = req;
skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
drbg_skcipher_cb, drbg);
skcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
CRYPTO_TFM_REQ_MAY_SLEEP,
crypto_req_done, &drbg->ctr_wait);
alignmask = crypto_skcipher_alignmask(sk_tfm);
drbg->ctr_null_value_buf = kzalloc(DRBG_CTR_NULL_LEN + alignmask,
@ -1762,21 +1753,12 @@ static int drbg_kcapi_sym_ctr(struct drbg_state *drbg,
/* Output buffer may not be valid for SGL, use scratchpad */
skcipher_request_set_crypt(drbg->ctr_req, &sg_in, &sg_out,
cryptlen, drbg->V);
ret = crypto_skcipher_encrypt(drbg->ctr_req);
switch (ret) {
case 0:
break;
case -EINPROGRESS:
case -EBUSY:
wait_for_completion(&drbg->ctr_completion);
if (!drbg->ctr_async_err) {
reinit_completion(&drbg->ctr_completion);
break;
}
default:
ret = crypto_wait_req(crypto_skcipher_encrypt(drbg->ctr_req),
&drbg->ctr_wait);
if (ret)
goto out;
}
init_completion(&drbg->ctr_completion);
crypto_init_wait(&drbg->ctr_wait);
memcpy(outbuf, drbg->outscratchpad, cryptlen);

3
include/crypto/drbg.h
View File

@ -126,8 +126,7 @@ struct drbg_state {
__u8 *ctr_null_value; /* CTR mode aligned zero buf */
__u8 *outscratchpadbuf; /* CTR mode output scratchpad */
__u8 *outscratchpad; /* CTR mode aligned outbuf */
struct completion ctr_completion; /* CTR mode async handler */
int ctr_async_err; /* CTR mode async error */
struct crypto_wait ctr_wait; /* CTR mode async wait obj */
bool seeded; /* DRBG fully seeded? */
bool pr; /* Prediction resistance enabled? */