crypto: ccp - Rework the unit-size check for XTS-AES

The CCP supports a limited set of unit-size values. Change the check
for this parameter such that acceptable values match the enumeration.
Then clarify the conditions under which we must use the fallback
implementation.

Signed-off-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Gary R Hook 2017-07-25 14:21:34 -05:00 committed by Herbert Xu
parent 47f27f160b
commit 7f7216cfaf
1 changed files with 26 additions and 43 deletions

View File

@ -39,46 +39,26 @@ struct ccp_unit_size_map {
u32 value; u32 value;
}; };
static struct ccp_unit_size_map unit_size_map[] = { static struct ccp_unit_size_map xts_unit_sizes[] = {
{ {
.size = 4096, .size = 16,
.value = CCP_XTS_AES_UNIT_SIZE_4096, .value = CCP_XTS_AES_UNIT_SIZE_16,
},
{
.size = 2048,
.value = CCP_XTS_AES_UNIT_SIZE_2048,
},
{
.size = 1024,
.value = CCP_XTS_AES_UNIT_SIZE_1024,
}, },
{ {
.size = 512, .size = 512,
.value = CCP_XTS_AES_UNIT_SIZE_512, .value = CCP_XTS_AES_UNIT_SIZE_512,
}, },
{ {
.size = 256, .size = 1024,
.value = CCP_XTS_AES_UNIT_SIZE__LAST, .value = CCP_XTS_AES_UNIT_SIZE_1024,
}, },
{ {
.size = 128, .size = 2048,
.value = CCP_XTS_AES_UNIT_SIZE__LAST, .value = CCP_XTS_AES_UNIT_SIZE_2048,
}, },
{ {
.size = 64, .size = 4096,
.value = CCP_XTS_AES_UNIT_SIZE__LAST, .value = CCP_XTS_AES_UNIT_SIZE_4096,
},
{
.size = 32,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
},
{
.size = 16,
.value = CCP_XTS_AES_UNIT_SIZE_16,
},
{
.size = 1,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
}, },
}; };
@ -138,16 +118,19 @@ static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
if (!req->info) if (!req->info)
return -EINVAL; return -EINVAL;
/* Check conditions under which the CCP can fulfill a request. The
* device can handle input plaintext of a length that is a multiple
* of the unit_size, bug the crypto implementation only supports
* the unit_size being equal to the input length. This limits the
* number of scenarios we can handle.
*/
unit_size = CCP_XTS_AES_UNIT_SIZE__LAST; unit_size = CCP_XTS_AES_UNIT_SIZE__LAST;
if (req->nbytes <= unit_size_map[0].size) { for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++) { if (req->nbytes == xts_unit_sizes[unit].size) {
if (!(req->nbytes & (unit_size_map[unit].size - 1))) { unit_size = unit;
unit_size = unit_size_map[unit].value;
break; break;
} }
} }
}
if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) || if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) ||
(ctx->u.aes.key_len != AES_KEYSIZE_128)) { (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher); SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher);