crypto: blake2s - move update and final logic to internal/blake2s.h

Move most of blake2s_update() and blake2s_final() into new inline
functions __blake2s_update() and __blake2s_final() in
include/crypto/internal/blake2s.h so that this logic can be shared by
the shash helper functions.  This will avoid duplicating this logic
between the library and shash implementations.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 41 insertions, 0 deletions

diff --git a/include/crypto/internal/blake2s.h b/include/crypto/internal/blake2s.h
index 6e376ae6b6b5..42deba4b8cee 100644
--- a/include/crypto/internal/blake2s.h
+++ b/include/crypto/internal/blake2s.h
@@ -4,6 +4,7 @@
 #define BLAKE2S_INTERNAL_H
 
 #include <crypto/blake2s.h>
+#include <linux/string.h>
 
 struct blake2s_tfm_ctx {
 	u8 key[BLAKE2S_KEY_SIZE];
@@ -23,4 +24,44 @@ static inline void blake2s_set_lastblock(struct blake2s_state *state)
 	state->f[0] = -1;
 }
 
+typedef void (*blake2s_compress_t)(struct blake2s_state *state,
+				   const u8 *block, size_t nblocks, u32 inc);
+
+static inline void __blake2s_update(struct blake2s_state *state,
+				    const u8 *in, size_t inlen,
+				    blake2s_compress_t compress)
+{
+	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
+
+	if (unlikely(!inlen))
+		return;
+	if (inlen > fill) {
+		memcpy(state->buf + state->buflen, in, fill);
+		(*compress)(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
+		state->buflen = 0;
+		in += fill;
+		inlen -= fill;
+	}
+	if (inlen > BLAKE2S_BLOCK_SIZE) {
+		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
+		/* Hash one less (full) block than strictly possible */
+		(*compress)(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
+		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
+		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
+	}
+	memcpy(state->buf + state->buflen, in, inlen);
+	state->buflen += inlen;
+}
+
+static inline void __blake2s_final(struct blake2s_state *state, u8 *out,
+				   blake2s_compress_t compress)
+{
+	blake2s_set_lastblock(state);
+	memset(state->buf + state->buflen, 0,
+	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
+	(*compress)(state, state->buf, 1, state->buflen);
+	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
+	memcpy(out, state->h, state->outlen);
+}
+
 #endif /* BLAKE2S_INTERNAL_H */