Eric Biggers 877b5691f2 crypto: shash - remove shash_desc::flags
The flags field in 'struct shash_desc' never actually does anything.
The only ostensibly supported flag is CRYPTO_TFM_REQ_MAY_SLEEP.
However, no shash algorithm ever sleeps, making this flag a no-op.

With this being the case, inevitably some users who can't sleep wrongly
pass MAY_SLEEP.  These would all need to be fixed if any shash algorithm
actually started sleeping.  For example, the shash_ahash_*() functions,
which wrap a shash algorithm with the ahash API, pass through MAY_SLEEP
from the ahash API to the shash API.  However, the shash functions are
called under kmap_atomic(), so actually they're assumed to never sleep.

Even if it turns out that some users do need preemption points while
hashing large buffers, we could easily provide a helper function
crypto_shash_update_large() which divides the data into smaller chunks
and calls crypto_shash_update() and cond_resched() for each chunk.  It's
not necessary to have a flag in 'struct shash_desc', nor is it necessary
to make individual shash algorithms aware of this at all.

Therefore, remove shash_desc::flags, and document that the
crypto_shash_*() functions can be called from any context.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-04-25 15:38:12 +08:00

90 lines
2.1 KiB
C

/* Orinoco MIC helpers
*
* See copyright notice in main.c
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/if_ether.h>
#include <linux/scatterlist.h>
#include <crypto/hash.h>
#include "orinoco.h"
#include "mic.h"
/********************************************************************/
/* Michael MIC crypto setup */
/********************************************************************/
int orinoco_mic_init(struct orinoco_private *priv)
{
priv->tx_tfm_mic = crypto_alloc_shash("michael_mic", 0, 0);
if (IS_ERR(priv->tx_tfm_mic)) {
printk(KERN_DEBUG "%s: could not allocate "
"crypto API michael_mic\n", __func__);
priv->tx_tfm_mic = NULL;
return -ENOMEM;
}
priv->rx_tfm_mic = crypto_alloc_shash("michael_mic", 0, 0);
if (IS_ERR(priv->rx_tfm_mic)) {
printk(KERN_DEBUG "%s: could not allocate "
"crypto API michael_mic\n", __func__);
priv->rx_tfm_mic = NULL;
return -ENOMEM;
}
return 0;
}
void orinoco_mic_free(struct orinoco_private *priv)
{
if (priv->tx_tfm_mic)
crypto_free_shash(priv->tx_tfm_mic);
if (priv->rx_tfm_mic)
crypto_free_shash(priv->rx_tfm_mic);
}
int orinoco_mic(struct crypto_shash *tfm_michael, u8 *key,
u8 *da, u8 *sa, u8 priority,
u8 *data, size_t data_len, u8 *mic)
{
SHASH_DESC_ON_STACK(desc, tfm_michael);
u8 hdr[ETH_HLEN + 2]; /* size of header + padding */
int err;
if (tfm_michael == NULL) {
printk(KERN_WARNING "%s: tfm_michael == NULL\n", __func__);
return -1;
}
/* Copy header into buffer. We need the padding on the end zeroed */
memcpy(&hdr[0], da, ETH_ALEN);
memcpy(&hdr[ETH_ALEN], sa, ETH_ALEN);
hdr[ETH_ALEN * 2] = priority;
hdr[ETH_ALEN * 2 + 1] = 0;
hdr[ETH_ALEN * 2 + 2] = 0;
hdr[ETH_ALEN * 2 + 3] = 0;
desc->tfm = tfm_michael;
err = crypto_shash_setkey(tfm_michael, key, MIC_KEYLEN);
if (err)
return err;
err = crypto_shash_init(desc);
if (err)
return err;
err = crypto_shash_update(desc, hdr, sizeof(hdr));
if (err)
return err;
err = crypto_shash_update(desc, data, data_len);
if (err)
return err;
err = crypto_shash_final(desc, mic);
shash_desc_zero(desc);
return err;
}