Re: [PATCH 3/8] crypto: ccp: Use precalculated hash from headers

From: Tom Lendacky
Date: Thu Oct 22 2015 - 14:18:43 EST


On 10/20/2015 02:33 AM, LABBE Corentin wrote:
Precalculated hash for empty message are now present in hash headers.
This patch just use them.

Signed-off-by: LABBE Corentin <clabbe.montjoie@xxxxxxxxx>

Tested-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Acked-by: Tom Lendacky <thomas.lendacky@xxxxxxx>

---
drivers/crypto/ccp/ccp-ops.c | 39 ++++++++-------------------------------
1 file changed, 8 insertions(+), 31 deletions(-)

diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
index d09c6c4..64fac2b 100644
--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -152,32 +152,6 @@ static const __be32 ccp_sha256_init[CCP_SHA_CTXSIZE / sizeof(__be32)] = {
cpu_to_be32(SHA256_H6), cpu_to_be32(SHA256_H7),
};

-/* The CCP cannot perform zero-length sha operations so the caller
- * is required to buffer data for the final operation. However, a
- * sha operation for a message with a total length of zero is valid
- * so known values are required to supply the result.
- */
-static const u8 ccp_sha1_zero[CCP_SHA_CTXSIZE] = {
- 0xda, 0x39, 0xa3, 0xee, 0x5e, 0x6b, 0x4b, 0x0d,
- 0x32, 0x55, 0xbf, 0xef, 0x95, 0x60, 0x18, 0x90,
- 0xaf, 0xd8, 0x07, 0x09, 0x00, 0x00, 0x00, 0x00,
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-};
-
-static const u8 ccp_sha224_zero[CCP_SHA_CTXSIZE] = {
- 0xd1, 0x4a, 0x02, 0x8c, 0x2a, 0x3a, 0x2b, 0xc9,
- 0x47, 0x61, 0x02, 0xbb, 0x28, 0x82, 0x34, 0xc4,
- 0x15, 0xa2, 0xb0, 0x1f, 0x82, 0x8e, 0xa6, 0x2a,
- 0xc5, 0xb3, 0xe4, 0x2f, 0x00, 0x00, 0x00, 0x00,
-};
-
-static const u8 ccp_sha256_zero[CCP_SHA_CTXSIZE] = {
- 0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14,
- 0x9a, 0xfb, 0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24,
- 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b, 0x93, 0x4c,
- 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55,
-};
-
static u32 ccp_addr_lo(struct ccp_dma_info *info)
{
return lower_32_bits(info->address + info->offset);
@@ -1388,18 +1362,21 @@ static int ccp_run_sha_cmd(struct ccp_cmd_queue *cmd_q, struct ccp_cmd *cmd)
if (sha->msg_bits)
return -EINVAL;

- /* A sha operation for a message with a total length of zero,
- * return known result.
+ /* The CCP cannot perform zero-length sha operations so the
+ * caller is required to buffer data for the final operation.
+ * However, a sha operation for a message with a total length
+ * of zero is valid so known values are required to supply
+ * the result.
*/
switch (sha->type) {
case CCP_SHA_TYPE_1:
- sha_zero = ccp_sha1_zero;
+ sha_zero = sha1_zero_message_hash;
break;
case CCP_SHA_TYPE_224:
- sha_zero = ccp_sha224_zero;
+ sha_zero = sha224_zero_message_hash;
break;
case CCP_SHA_TYPE_256:
- sha_zero = ccp_sha256_zero;
+ sha_zero = sha256_zero_message_hash;
break;
default:
return -EINVAL;

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