crypto: blake2b - sync with blake2s implementation

Sync the BLAKE2b code with the BLAKE2s code as much as possible:

- Move a lot of code into new headers <crypto/blake2b.h> and
  <crypto/internal/blake2b.h>, and adjust it to be like the
  corresponding BLAKE2s code, i.e. like <crypto/blake2s.h> and
  <crypto/internal/blake2s.h>.

- Rename constants, e.g. BLAKE2B_*_DIGEST_SIZE => BLAKE2B_*_HASH_SIZE.

- Use a macro BLAKE2B_ALG() to define the shash_alg structs.

- Export blake2b_compress_generic() for use as a fallback.

This makes it much easier to add optimized implementations of BLAKE2b,
as optimized implementations can use the helper functions
crypto_blake2b_{setkey,init,update,final}() and
blake2b_compress_generic().  The ARM implementation will use these.

But this change is also helpful because it eliminates unnecessary
differences between the BLAKE2b and BLAKE2s code, so that the same
improvements can easily be made to both.  (The two algorithms are
basically identical, except for the word size and constants.)  It also
makes it straightforward to add a library API for BLAKE2b in the future
if/when it's needed.

This change does make the BLAKE2b code slightly more complicated than it
needs to be, as it doesn't actually provide a library API yet.  For
example, __blake2b_update() doesn't really need to exist yet; it could
just be inlined into crypto_blake2b_update().  But I believe this is
outweighed by the benefits of keeping the code in sync.

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, 48 insertions, 178 deletions

diff --git a/crypto/blake2b_generic.c b/crypto/blake2b_generic.c
index a2ffe60e06d3..963f7fe0e4ea 100644
--- a/crypto/blake2b_generic.c
+++ b/crypto/blake2b_generic.c
@@ -20,36 +20,11 @@
 
 #include <asm/unaligned.h>
 #include <linux/module.h>
-#include <linux/string.h>
 #include <linux/kernel.h>
 #include <linux/bitops.h>
+#include <crypto/internal/blake2b.h>
 #include <crypto/internal/hash.h>
 
-#define BLAKE2B_160_DIGEST_SIZE		(160 / 8)
-#define BLAKE2B_256_DIGEST_SIZE		(256 / 8)
-#define BLAKE2B_384_DIGEST_SIZE		(384 / 8)
-#define BLAKE2B_512_DIGEST_SIZE		(512 / 8)
-
-enum blake2b_constant {
-	BLAKE2B_BLOCKBYTES    = 128,
-	BLAKE2B_KEYBYTES      = 64,
-};
-
-struct blake2b_state {
-	u64      h[8];
-	u64      t[2];
-	u64      f[2];
-	u8       buf[BLAKE2B_BLOCKBYTES];
-	size_t   buflen;
-};
-
-static const u64 blake2b_IV[8] = {
-	0x6a09e667f3bcc908ULL, 0xbb67ae8584caa73bULL,
-	0x3c6ef372fe94f82bULL, 0xa54ff53a5f1d36f1ULL,
-	0x510e527fade682d1ULL, 0x9b05688c2b3e6c1fULL,
-	0x1f83d9abfb41bd6bULL, 0x5be0cd19137e2179ULL
-};
-
 static const u8 blake2b_sigma[12][16] = {
 	{  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15 },
 	{ 14, 10,  4,  8,  9, 15, 13,  6,  1, 12,  0,  2, 11,  7,  5,  3 },
@@ -95,8 +70,8 @@ static void blake2b_increment_counter(struct blake2b_state *S, const u64 inc)
 		G(r,7,v[ 3],v[ 4],v[ 9],v[14]); \
 	} while (0)
 
-static void blake2b_compress(struct blake2b_state *S,
-			     const u8 block[BLAKE2B_BLOCKBYTES])
+static void blake2b_compress_one_generic(struct blake2b_state *S,
+					 const u8 block[BLAKE2B_BLOCK_SIZE])
 {
 	u64 m[16];
 	u64 v[16];
@@ -108,14 +83,14 @@ static void blake2b_compress(struct blake2b_state *S,
 	for (i = 0; i < 8; ++i)
 		v[i] = S->h[i];
 
-	v[ 8] = blake2b_IV[0];
-	v[ 9] = blake2b_IV[1];
-	v[10] = blake2b_IV[2];
-	v[11] = blake2b_IV[3];
-	v[12] = blake2b_IV[4] ^ S->t[0];
-	v[13] = blake2b_IV[5] ^ S->t[1];
-	v[14] = blake2b_IV[6] ^ S->f[0];
-	v[15] = blake2b_IV[7] ^ S->f[1];
+	v[ 8] = BLAKE2B_IV0;
+	v[ 9] = BLAKE2B_IV1;
+	v[10] = BLAKE2B_IV2;
+	v[11] = BLAKE2B_IV3;
+	v[12] = BLAKE2B_IV4 ^ S->t[0];
+	v[13] = BLAKE2B_IV5 ^ S->t[1];
+	v[14] = BLAKE2B_IV6 ^ S->f[0];
+	v[15] = BLAKE2B_IV7 ^ S->f[1];
 
 	ROUND(0);
 	ROUND(1);
@@ -139,159 +114,54 @@ static void blake2b_compress(struct blake2b_state *S,
 #undef G
 #undef ROUND
 
-struct blake2b_tfm_ctx {
-	u8 key[BLAKE2B_KEYBYTES];
-	unsigned int keylen;
-};
-
-static int blake2b_setkey(struct crypto_shash *tfm, const u8 *key,
-			  unsigned int keylen)
+void blake2b_compress_generic(struct blake2b_state *state,
+			      const u8 *block, size_t nblocks, u32 inc)
 {
-	struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(tfm);
-
-	if (keylen == 0 || keylen > BLAKE2B_KEYBYTES)
-		return -EINVAL;
-
-	memcpy(tctx->key, key, keylen);
-	tctx->keylen = keylen;
-
-	return 0;
+	do {
+		blake2b_increment_counter(state, inc);
+		blake2b_compress_one_generic(state, block);
+		block += BLAKE2B_BLOCK_SIZE;
+	} while (--nblocks);
 }
+EXPORT_SYMBOL(blake2b_compress_generic);
 
-static int blake2b_init(struct shash_desc *desc)
+static int crypto_blake2b_update_generic(struct shash_desc *desc,
+					 const u8 *in, unsigned int inlen)
 {
-	struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm);
-	struct blake2b_state *state = shash_desc_ctx(desc);
-	const int digestsize = crypto_shash_digestsize(desc->tfm);
-
-	memset(state, 0, sizeof(*state));
-	memcpy(state->h, blake2b_IV, sizeof(state->h));
-
-	/* Parameter block is all zeros except index 0, no xor for 1..7 */
-	state->h[0] ^= 0x01010000 | tctx->keylen << 8 | digestsize;
-
-	if (tctx->keylen) {
-		/*
-		 * Prefill the buffer with the key, next call to _update or
-		 * _final will process it
-		 */
-		memcpy(state->buf, tctx->key, tctx->keylen);
-		state->buflen = BLAKE2B_BLOCKBYTES;
-	}
-	return 0;
+	return crypto_blake2b_update(desc, in, inlen, blake2b_compress_generic);
 }
 
-static int blake2b_update(struct shash_desc *desc, const u8 *in,
-			  unsigned int inlen)
+static int crypto_blake2b_final_generic(struct shash_desc *desc, u8 *out)
 {
-	struct blake2b_state *state = shash_desc_ctx(desc);
-	const size_t left = state->buflen;
-	const size_t fill = BLAKE2B_BLOCKBYTES - left;
-
-	if (!inlen)
-		return 0;
-
-	if (inlen > fill) {
-		state->buflen = 0;
-		/* Fill buffer */
-		memcpy(state->buf + left, in, fill);
-		blake2b_increment_counter(state, BLAKE2B_BLOCKBYTES);
-		/* Compress */
-		blake2b_compress(state, state->buf);
-		in += fill;
-		inlen -= fill;
-		while (inlen > BLAKE2B_BLOCKBYTES) {
-			blake2b_increment_counter(state, BLAKE2B_BLOCKBYTES);
-			blake2b_compress(state, in);
-			in += BLAKE2B_BLOCKBYTES;
-			inlen -= BLAKE2B_BLOCKBYTES;
-		}
-	}
-	memcpy(state->buf + state->buflen, in, inlen);
-	state->buflen += inlen;
-
-	return 0;
+	return crypto_blake2b_final(desc, out, blake2b_compress_generic);
 }
 
-static int blake2b_final(struct shash_desc *desc, u8 *out)
-{
-	struct blake2b_state *state = shash_desc_ctx(desc);
-	const int digestsize = crypto_shash_digestsize(desc->tfm);
-	size_t i;
-
-	blake2b_increment_counter(state, state->buflen);
-	/* Set last block */
-	state->f[0] = (u64)-1;
-	/* Padding */
-	memset(state->buf + state->buflen, 0, BLAKE2B_BLOCKBYTES - state->buflen);
-	blake2b_compress(state, state->buf);
-
-	/* Avoid temporary buffer and switch the internal output to LE order */
-	for (i = 0; i < ARRAY_SIZE(state->h); i++)
-		__cpu_to_le64s(&state->h[i]);
-
-	memcpy(out, state->h, digestsize);
-	return 0;
-}
+#define BLAKE2B_ALG(name, driver_name, digest_size)			\
+	{								\
+		.base.cra_name		= name,				\
+		.base.cra_driver_name	= driver_name,			\
+		.base.cra_priority	= 100,				\
+		.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,	\
+		.base.cra_blocksize	= BLAKE2B_BLOCK_SIZE,		\
+		.base.cra_ctxsize	= sizeof(struct blake2b_tfm_ctx), \
+		.base.cra_module	= THIS_MODULE,			\
+		.digestsize		= digest_size,			\
+		.setkey			= crypto_blake2b_setkey,	\
+		.init			= crypto_blake2b_init,		\
+		.update			= crypto_blake2b_update_generic, \
+		.final			= crypto_blake2b_final_generic,	\
+		.descsize		= sizeof(struct blake2b_state),	\
+	}
 
 static struct shash_alg blake2b_algs[] = {
-	{
-		.base.cra_name		= "blake2b-160",
-		.base.cra_driver_name	= "blake2b-160-generic",
-		.base.cra_priority	= 100,
-		.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
-		.base.cra_blocksize	= BLAKE2B_BLOCKBYTES,
-		.base.cra_ctxsize	= sizeof(struct blake2b_tfm_ctx),
-		.base.cra_module	= THIS_MODULE,
-		.digestsize		= BLAKE2B_160_DIGEST_SIZE,
-		.setkey			= blake2b_setkey,
-		.init			= blake2b_init,
-		.update			= blake2b_update,
-		.final			= blake2b_final,
-		.descsize		= sizeof(struct blake2b_state),
-	}, {
-		.base.cra_name		= "blake2b-256",
-		.base.cra_driver_name	= "blake2b-256-generic",
-		.base.cra_priority	= 100,
-		.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
-		.base.cra_blocksize	= BLAKE2B_BLOCKBYTES,
-		.base.cra_ctxsize	= sizeof(struct blake2b_tfm_ctx),
-		.base.cra_module	= THIS_MODULE,
-		.digestsize		= BLAKE2B_256_DIGEST_SIZE,
-		.setkey			= blake2b_setkey,
-		.init			= blake2b_init,
-		.update			= blake2b_update,
-		.final			= blake2b_final,
-		.descsize		= sizeof(struct blake2b_state),
-	}, {
-		.base.cra_name		= "blake2b-384",
-		.base.cra_driver_name	= "blake2b-384-generic",
-		.base.cra_priority	= 100,
-		.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
-		.base.cra_blocksize	= BLAKE2B_BLOCKBYTES,
-		.base.cra_ctxsize	= sizeof(struct blake2b_tfm_ctx),
-		.base.cra_module	= THIS_MODULE,
-		.digestsize		= BLAKE2B_384_DIGEST_SIZE,
-		.setkey			= blake2b_setkey,
-		.init			= blake2b_init,
-		.update			= blake2b_update,
-		.final			= blake2b_final,
-		.descsize		= sizeof(struct blake2b_state),
-	}, {
-		.base.cra_name		= "blake2b-512",
-		.base.cra_driver_name	= "blake2b-512-generic",
-		.base.cra_priority	= 100,
-		.base.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
-		.base.cra_blocksize	= BLAKE2B_BLOCKBYTES,
-		.base.cra_ctxsize	= sizeof(struct blake2b_tfm_ctx),
-		.base.cra_module	= THIS_MODULE,
-		.digestsize		= BLAKE2B_512_DIGEST_SIZE,
-		.setkey			= blake2b_setkey,
-		.init			= blake2b_init,
-		.update			= blake2b_update,
-		.final			= blake2b_final,
-		.descsize		= sizeof(struct blake2b_state),
-	}
+	BLAKE2B_ALG("blake2b-160", "blake2b-160-generic",
+		    BLAKE2B_160_HASH_SIZE),
+	BLAKE2B_ALG("blake2b-256", "blake2b-256-generic",
+		    BLAKE2B_256_HASH_SIZE),
+	BLAKE2B_ALG("blake2b-384", "blake2b-384-generic",
+		    BLAKE2B_384_HASH_SIZE),
+	BLAKE2B_ALG("blake2b-512", "blake2b-512-generic",
+		    BLAKE2B_512_HASH_SIZE),
 };
 
 static int __init blake2b_mod_init(void)