From: Ryan Wanner <Ryan.Wanner@xxxxxxxxxxxxx>
Add softare padding to hmac-sha digest for zero length messages.
Using the atmel_sha_fill_padding() to fill the buffer with a padded
empty message with a length of the block size.
Create a temporary scatter list from the padded buffer to pass into the
data processing functions.
Signed-off-by: Ryan Wanner <Ryan.Wanner@xxxxxxxxxxxxx>
---
drivers/crypto/atmel-sha.c | 34 ++++++++++++++++++++++++++++++----
1 file changed, 30 insertions(+), 4 deletions(-)
diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c
index 00be792e605c..b42e3a0b8cb5 100644
--- a/drivers/crypto/atmel-sha.c
+++ b/drivers/crypto/atmel-sha.c
@@ -1948,14 +1948,32 @@ static int atmel_sha_hmac_digest2(struct atmel_sha_dev *dd)
struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);
struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
struct atmel_sha_hmac_ctx *hmac = crypto_ahash_ctx(tfm);
+ struct scatterlist *sgbuf;
size_t hs = ctx->hash_size;
size_t i, num_words = hs / sizeof(u32);
bool use_dma = false;
u32 mr;
/* Special case for empty message. */
- if (!req->nbytes)
- return atmel_sha_complete(dd, -EINVAL); // TODO:
+ if (!req->nbytes) {
+ req->nbytes = 0;
+ ctx->bufcnt = 0;
+ ctx->digcnt[0] = 0;
+ ctx->digcnt[1] = 0;
+ switch (ctx->flags & SHA_FLAGS_ALGO_MASK) {
+ case SHA_FLAGS_SHA1:
+ case SHA_FLAGS_SHA224:
+ case SHA_FLAGS_SHA256:
+ atmel_sha_fill_padding(ctx, 64);
+ break;
+
+ case SHA_FLAGS_SHA384:
+ case SHA_FLAGS_SHA512:
+ atmel_sha_fill_padding(ctx, 128);
+ break;
+ }
+ sg_init_one(&dd->tmp, ctx->buffer, ctx->bufcnt);
+ }
/* Check DMA threshold and alignment. */
if (req->nbytes > ATMEL_SHA_DMA_THRESHOLD &&
@@ -1985,12 +2003,20 @@ static int atmel_sha_hmac_digest2(struct atmel_sha_dev *dd)
atmel_sha_write(dd, SHA_CR, SHA_CR_FIRST);
+ /* Special case for empty message. */
+ if (!req->nbytes) {
+ sgbuf = &dd->tmp;
+ req->nbytes = ctx->bufcnt;
+ } else {
+ sgbuf = req->src;
+ }
+
/* Process data. */
if (use_dma)
- return atmel_sha_dma_start(dd, req->src, req->nbytes,
+ return atmel_sha_dma_start(dd, sgbuf, req->nbytes,
atmel_sha_hmac_final_done);
- return atmel_sha_cpu_start(dd, req->src, req->nbytes, false, true,
+ return atmel_sha_cpu_start(dd, sgbuf, req->nbytes, false, true,
atmel_sha_hmac_final_done);
}
--
2.37.2
