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authorRyan Wanner <Ryan.Wanner@microchip.com>2023-03-28 12:56:26 -0700
committerHerbert Xu <herbert@gondor.apana.org.au>2023-04-06 16:41:28 +0800
commit232c1e8e19ff8e60237012fadead02557aafca5a (patch)
tree0362b66282a5a637c74c0e47a79a4ebdb19cb524 /drivers/crypto
parenta4b16dad46576ce08ecb660fc923d0857dcae107 (diff)
downloadlinux-stable-232c1e8e19ff8e60237012fadead02557aafca5a.tar.gz
crypto: atmel-sha - Add zero length message digest support for hmac
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@microchip.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/atmel-sha.c34
1 files changed, 30 insertions, 4 deletions
diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c
index e7c1db2739ec..6bef634d3c86 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);
}