crypto: blake2b - simplify key init

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@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/blake2b_generic.c b/crypto/blake2b_generic.c
index d3da611..fd0fbb0 100644 (file)
--- 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;
 }