[PATCH 13/19] crypto: sun8i-ss: Add function for handling hash padding

Corentin Labbe
2022-03-17T20:56:52Z

Move all padding work to a dedicated function.

Signed-off-by: Corentin Labbe <clabbe@baylibre.com>
---
.../crypto/allwinner/sun8i-ss/sun8i-ss-hash.c | 87 ++++++++++++++-----
1 file changed, 65 insertions(+), 22 deletions(-)

diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
index cb510ec21ec4..6adb6a0428b7 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-hash.c
@@ -328,6 +328,64 @@ int sun8i_ss_hash_digest(struct ahash_request *areq)
return crypto_transfer_hash_request_to_engine(engine, areq);
}

+static u64 hash_pad(u32 *buf, unsigned int bufsize, u64 padi, u64 byte_count, bool le, int bs)
+{
+ u64 fill, min_fill, j, k;
+ __be64 *bebits;
+ __le64 *lebits;
+
+ j = padi;
+ buf[j++] = cpu_to_le32(0x80);
+
+ if (bs == 64) {
+ fill = 64 - (byte_count % 64);
+ min_fill = 2 * sizeof(u32) + sizeof(u32);
+ } else {
+ fill = 128 - (byte_count % 128);
+ min_fill = 4 * sizeof(u32) + sizeof(u32);
+ }
+
+ if (fill < min_fill)
+ fill += bs;
+
+ k = j;
+ j += (fill - min_fill) / sizeof(u32);
+ if (j * 4 > bufsize) {
+ pr_err("%s OVERFLOW %llu\n", __func__, j);
+ return 0;
+ }
+ for (; k < j; k++)
+ buf[k] = 0;
+
+ if (le) {
+ /* MD5 */
+ lebits = (__le64 *)&buf[j];
+ *lebits = cpu_to_le64(byte_count << 3);
+ j += 2;
+ } else {
+ if (bs == 64) {
+ /* sha1 sha224 sha256 */
+ bebits = (__be64 *)&buf[j];
+ *bebits = cpu_to_be64(byte_count << 3);
+ j += 2;
+ } else {
+ /* sha384 sha512*/
+ bebits = (__be64 *)&buf[j];
+ *bebits = cpu_to_be64(byte_count >> 61);
+ j += 2;
+ bebits = (__be64 *)&buf[j];
+ *bebits = cpu_to_be64(byte_count << 3);
+ j += 2;
+ }
+ }
+ if (j * 4 > bufsize) {
+ pr_err("%s OVERFLOW %llu\n", __func__, j);
+ return 0;
+ }
+
+ return j;
+}
+
/* sun8i_ss_hash_run - run an ahash request
* Send the data of the request to the SS along with an extra SG with padding
*/
@@ -342,11 +400,9 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
struct scatterlist *sg;
int nr_sgs, err, digestsize;
unsigned int len;
- u64 fill, min_fill, byte_count;
+ u64 byte_count;
void *pad, *result;
int j, i, k, todo;
- __be64 *bebits;
- __le64 *lebits;
dma_addr_t addr_res, addr_pad;
__le32 *bf;

@@ -421,33 +477,20 @@ int sun8i_ss_hash_run(struct crypto_engine *engine, void *breq)
i--;

byte_count = areq->nbytes;
- bf[j++] = cpu_to_le32(0x80);
-
- fill = 64 - (byte_count % 64);
- min_fill = 3 * sizeof(u32);
-
- if (fill < min_fill)
- fill += 64;
-
- k = j;
- j += (fill - min_fill) / sizeof(u32);
- for (; k < j; k++)
- bf[k] = 0;
-
switch (algt->ss_algo_id) {
case SS_ID_HASH_MD5:
- lebits = (__le64 *)&bf[j];
- *lebits = cpu_to_le64(byte_count << 3);
- j += 2;
+ j = hash_pad(bf, 4096, j, byte_count, true, bs);
break;
case SS_ID_HASH_SHA1:
case SS_ID_HASH_SHA224:
case SS_ID_HASH_SHA256:
- bebits = (__be64 *)&bf[j];
- *bebits = cpu_to_be64(byte_count << 3);
- j += 2;
+ j = hash_pad(bf, 4096, j, byte_count, false, bs);
break;
}
+ if (!j) {
+ err = -EINVAL;
+ goto theend;
+ }

addr_pad = dma_map_single(ss->dev, pad, j * 4, DMA_TO_DEVICE);
if (dma_mapping_error(ss->dev, addr_pad)) {
--
2.34.1