On 7/21/2017 2:05 PM, Gary R Hook wrote:
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@xxxxxxx>
---
drivers/crypto/ccp/ccp-crypto-aes-xts.c | 75 ++++++++++++++-----------------
1 file changed, 35 insertions(+), 40 deletions(-)
diff --git a/drivers/crypto/ccp/ccp-crypto-aes-xts.c b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
index 4a313f62dbea..3c37794ffe2d 100644
--- a/drivers/crypto/ccp/ccp-crypto-aes-xts.c
+++ b/drivers/crypto/ccp/ccp-crypto-aes-xts.c
@@ -1,8 +1,9 @@
/*
* AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support
*
- * Copyright (C) 2013 Advanced Micro Devices, Inc.
+ * Copyright (C) 2013,2017 Advanced Micro Devices, Inc.
*
+ * Author: Gary R Hook <gary.hook@xxxxxxx>
* Author: Tom Lendacky <thomas.lendacky@xxxxxxx>
*
* This program is free software; you can redistribute it and/or modify
@@ -38,46 +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,
},
};
@@ -124,7 +105,9 @@ static int ccp_aes_xts_crypt(struct ablkcipher_request *req,
{
struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm);
struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req);
+ unsigned int fallback = 0;
unsigned int unit;
+ u32 block_size;
I don't see this variable used anywhere. It should be deleted.
u32 unit_size;
int ret;
@@ -137,18 +120,30 @@ 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. Also validate the key length.
Remove the "Also validate the key length." since that happens below and
is covered by a different comment.
+ */
+ block_size = 0;
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;
+ block_size = xts_unit_sizes[unit].size;
+ break;
}
}
-
- if ((unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) ||
- (ctx->u.aes.key_len != AES_KEYSIZE_128)) {
+ /* The CCP has restrictions on block sizes. Also, a version 3 device
+ * only supports AES-128 operations; version 5 CCPs support both
+ * AES-128 and -256 operations.
The 256-bit XTS support isn't here yet, so shouldn't mention it now.
+ */
+ if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST)
+ fallback = 1;
+ if (ctx->u.aes.key_len != AES_KEYSIZE_128)
+ fallback = 1;
+ if (fallback) {
It appears these changes are not necessary... It does the same thing as
the previous check. Just make the changes when the XTS-256 support is
added in the next patch.
Thanks,
Tom
SKCIPHER_REQUEST_ON_STACK(subreq, ctx->u.aes.tfm_skcipher);
/* Use the fallback to process the request for any
