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>

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 */

lib/crypto/blake2s.c

@@ -15,55 +15,23 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/bug.h>
-#include <asm/unaligned.h>
+
+#if IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S)
+#  define blake2s_compress blake2s_compress_arch
+#else
+#  define blake2s_compress blake2s_compress_generic
+#endif
 
 void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen)
 {
-	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
-
-	if (unlikely(!inlen))
-		return;
-	if (inlen > fill) {
-		memcpy(state->buf + state->buflen, in, fill);
-		if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S))
-			blake2s_compress_arch(state, state->buf, 1,
-					      BLAKE2S_BLOCK_SIZE);
-		else
-			blake2s_compress_generic(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 */
-		if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S))
-			blake2s_compress_arch(state, in, nblocks - 1,
-					      BLAKE2S_BLOCK_SIZE);
-		else
-			blake2s_compress_generic(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;
+	__blake2s_update(state, in, inlen, blake2s_compress);
 }
 EXPORT_SYMBOL(blake2s_update);
 
 void blake2s_final(struct blake2s_state *state, u8 *out)
 {
 	WARN_ON(IS_ENABLED(DEBUG) && !out);
-	blake2s_set_lastblock(state);
-	memset(state->buf + state->buflen, 0,
-	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
-	if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S))
-		blake2s_compress_arch(state, state->buf, 1, state->buflen);
-	else
-		blake2s_compress_generic(state, state->buf, 1, state->buflen);
-	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
-	memcpy(out, state->h, state->outlen);
+	__blake2s_final(state, out, blake2s_compress);
 	memzero_explicit(state, sizeof(*state));
 }
 EXPORT_SYMBOL(blake2s_final);