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authorGary R Hook <gary.hook@amd.com>2017-07-25 21:21:34 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2017-08-04 03:27:43 +0200
commit7f7216cfaf3f07a41fe6e88b779bdc9690c2d515 (patch)
treee24603f4ffad3638f334c2fb2d73c4147a921afc
parentcrypto: ccp - Add a call to xts_check_key() (diff)
downloadlinux-7f7216cfaf3f07a41fe6e88b779bdc9690c2d515.tar.xz
linux-7f7216cfaf3f07a41fe6e88b779bdc9690c2d515.zip
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>
-rw-r--r--drivers/crypto/ccp/ccp-crypto-aes-xts.c57
1 files changed, 20 insertions, 37 deletions
diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
index 2b5d3a62fad9..5c2df880ab48 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-xts.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
@@ -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,
+ .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;
- break;
- }
+ 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);