The keyed init writes the key bytes to the input buffer and does an
update. We can do that in two ways: fill the buffer and update
immediatelly. This is what current blake2b_init_key does. Any other
following _update or _final will continue from the updated state.
The other way is to write the key and set the number of bytes to process
at the next _update or _final, lazy evaluation. Which leads to the the
simplified code in this patch.
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
---
crypto/blake2b_generic.c | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)
diff --git a/crypto/blake2b_generic.c b/crypto/blake2b_generic.c
index d3da6113a96a..fd0fbb076058 100644
--- a/crypto/blake2b_generic.c
+++ b/crypto/blake2b_generic.c
@@ -85,8 +85,6 @@ static const u8 blake2b_sigma[12][16] = {
{ 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 }
};
-static void blake2b_update(struct blake2b_state *S, const void *pin, size_t inlen);
-
static void blake2b_set_lastnode(struct blake2b_state *S)
{
S->f[1] = (u64)-1;
@@ -235,12 +233,12 @@ static int blake2b_init(struct shash_desc *desc)
state->h[0] ^= 0x01010000 | mctx->keylen << 8 | digestsize;
if (mctx->keylen) {
- u8 block[BLAKE2B_BLOCKBYTES];
-
- memset(block, 0, BLAKE2B_BLOCKBYTES);
- memcpy(block, mctx->key, mctx->keylen);
- blake2b_update(state, block, BLAKE2B_BLOCKBYTES);
- memzero_explicit(block, BLAKE2B_BLOCKBYTES);
+ /*
+ * Prefill the buffer with the key, next call to _update or
+ * _final will process it
+ */
+ memcpy(state->buf, mctx->key, mctx->keylen);
+ state->buflen = BLAKE2B_BLOCKBYTES;
}
return 0;
}
--
2.23.0
