Commit 7f7216cf authored by Gary R Hook's avatar Gary R Hook Committed by Herbert Xu

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: default avatarGary R Hook <gary.hook@amd.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 47f27f16
......@@ -39,46 +39,26 @@ struct ccp_unit_size_map {
u32 value;
};
static struct ccp_unit_size_map unit_size_map[] = {
static struct ccp_unit_size_map xts_unit_sizes[] = {
{
.size = 4096,
.value = CCP_XTS_AES_UNIT_SIZE_4096,
},
{
.size = 2048,
.value = CCP_XTS_AES_UNIT_SIZE_2048,
},
{
.size = 1024,
.value = CCP_XTS_AES_UNIT_SIZE_1024,
.size = 16,
.value = CCP_XTS_AES_UNIT_SIZE_16,
},
{
.size = 512,
.value = CCP_XTS_AES_UNIT_SIZE_512,
},
{
.size = 256,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
},
{
.size = 128,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
},
{
.size = 64,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
},
{
.size = 32,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
.size = 1024,
.value = CCP_XTS_AES_UNIT_SIZE_1024,
},
{
.size = 16,
.value = CCP_XTS_AES_UNIT_SIZE_16,
.size = 2048,
.value = CCP_XTS_AES_UNIT_SIZE_2048,
},
{
.size = 1,
.value = CCP_XTS_AES_UNIT_SIZE__LAST,
.size = 4096,
.value = CCP_XTS_AES_UNIT_SIZE_4096,
},
};
......@@ -138,16 +118,19 @@ static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
if (!req->info)
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;
if (req->nbytes <= unit_size_map[0].size) {
for (unit = 0; unit < ARRAY_SIZE(unit_size_map); unit++) {
if (!(req->nbytes & (unit_size_map[unit].size - 1))) {
unit_size = unit_size_map[unit].value;
for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) {
if (req->nbytes == xts_unit_sizes[unit].size) {
unit_size = unit;
break;
}
}
}
if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) ||
(ctx->u.aes.key_len != AES_KEYSIZE_128)) {
SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher);
......
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