crypto: blake2s - generic C library implementation and selftest

The C implementation was originally based on Samuel Neves' public
domain reference implementation but has since been heavily modified
for the kernel. We're able to do compile-time optimizations by moving
some scaffolding around the final function into the header file.

Information: https://blake2.net/Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Samuel Neves <sneves@dei.uc.pt>
Co-developed-by: Samuel Neves <sneves@dei.uc.pt>
[ardb: - move from lib/zinc to lib/crypto
       - remove simd handling
       - rewrote selftest for better coverage
       - use fixed digest length for blake2s_hmac() and rename to
         blake2s256_hmac() ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

include/crypto/blake2s.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef BLAKE2S_H
+#define BLAKE2S_H
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+
+#include <asm/bug.h>
+
+enum blake2s_lengths {
+	BLAKE2S_BLOCK_SIZE = 64,
+	BLAKE2S_HASH_SIZE = 32,
+	BLAKE2S_KEY_SIZE = 32,
+
+	BLAKE2S_128_HASH_SIZE = 16,
+	BLAKE2S_160_HASH_SIZE = 20,
+	BLAKE2S_224_HASH_SIZE = 28,
+	BLAKE2S_256_HASH_SIZE = 32,
+};
+
+struct blake2s_state {
+	u32 h[8];
+	u32 t[2];
+	u32 f[2];
+	u8 buf[BLAKE2S_BLOCK_SIZE];
+	unsigned int buflen;
+	unsigned int outlen;
+};
+
+enum blake2s_iv {
+	BLAKE2S_IV0 = 0x6A09E667UL,
+	BLAKE2S_IV1 = 0xBB67AE85UL,
+	BLAKE2S_IV2 = 0x3C6EF372UL,
+	BLAKE2S_IV3 = 0xA54FF53AUL,
+	BLAKE2S_IV4 = 0x510E527FUL,
+	BLAKE2S_IV5 = 0x9B05688CUL,
+	BLAKE2S_IV6 = 0x1F83D9ABUL,
+	BLAKE2S_IV7 = 0x5BE0CD19UL,
+};
+
+void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen);
+void blake2s_final(struct blake2s_state *state, u8 *out);
+
+static inline void blake2s_init_param(struct blake2s_state *state,
+				      const u32 param)
+{
+	*state = (struct blake2s_state){{
+		BLAKE2S_IV0 ^ param,
+		BLAKE2S_IV1,
+		BLAKE2S_IV2,
+		BLAKE2S_IV3,
+		BLAKE2S_IV4,
+		BLAKE2S_IV5,
+		BLAKE2S_IV6,
+		BLAKE2S_IV7,
+	}};
+}
+
+static inline void blake2s_init(struct blake2s_state *state,
+				const size_t outlen)
+{
+	blake2s_init_param(state, 0x01010000 | outlen);
+	state->outlen = outlen;
+}
+
+static inline void blake2s_init_key(struct blake2s_state *state,
+				    const size_t outlen, const void *key,
+				    const size_t keylen)
+{
+	WARN_ON(IS_ENABLED(DEBUG) && (!outlen || outlen > BLAKE2S_HASH_SIZE ||
+		!key || !keylen || keylen > BLAKE2S_KEY_SIZE));
+
+	blake2s_init_param(state, 0x01010000 | keylen << 8 | outlen);
+	memcpy(state->buf, key, keylen);
+	state->buflen = BLAKE2S_BLOCK_SIZE;
+	state->outlen = outlen;
+}
+
+static inline void blake2s(u8 *out, const u8 *in, const u8 *key,
+			   const size_t outlen, const size_t inlen,
+			   const size_t keylen)
+{
+	struct blake2s_state state;
+
+	WARN_ON(IS_ENABLED(DEBUG) && ((!in && inlen > 0) || !out || !outlen ||
+		outlen > BLAKE2S_HASH_SIZE || keylen > BLAKE2S_KEY_SIZE ||
+		(!key && keylen)));
+
+	if (keylen)
+		blake2s_init_key(&state, outlen, key, keylen);
+	else
+		blake2s_init(&state, outlen);
+
+	blake2s_update(&state, in, inlen);
+	blake2s_final(&state, out);
+}
+
+void blake2s256_hmac(u8 *out, const u8 *in, const u8 *key, const size_t inlen,
+		     const size_t keylen);
+
+#endif /* BLAKE2S_H */

include/crypto/internal/blake2s.h

+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+
+#ifndef BLAKE2S_INTERNAL_H
+#define BLAKE2S_INTERNAL_H
+
+#include <crypto/blake2s.h>
+
+void blake2s_compress_generic(struct blake2s_state *state,const u8 *block,
+			      size_t nblocks, const u32 inc);
+
+void blake2s_compress_arch(struct blake2s_state *state,const u8 *block,
+			   size_t nblocks, const u32 inc);
+
+static inline void blake2s_set_lastblock(struct blake2s_state *state)
+{
+	state->f[0] = -1;
+}
+
+#endif /* BLAKE2S_INTERNAL_H */

lib/crypto/Kconfig

@@ -8,6 +8,31 @@ config CRYPTO_LIB_AES
 config CRYPTO_LIB_ARC4
 	tristate
 
+config CRYPTO_ARCH_HAVE_LIB_BLAKE2S
+	tristate
+	help
+	  Declares whether the architecture provides an arch-specific
+	  accelerated implementation of the Blake2s library interface,
+	  either builtin or as a module.
+
+config CRYPTO_LIB_BLAKE2S_GENERIC
+	tristate
+	help
+	  This symbol can be depended upon by arch implementations of the
+	  Blake2s library interface that require the generic code as a
+	  fallback, e.g., for SIMD implementations. If no arch specific
+	  implementation is enabled, this implementation serves the users
+	  of CRYPTO_LIB_BLAKE2S.
+
+config CRYPTO_LIB_BLAKE2S
+	tristate "BLAKE2s hash function library"
+	depends on CRYPTO_ARCH_HAVE_LIB_BLAKE2S || !CRYPTO_ARCH_HAVE_LIB_BLAKE2S
+	select CRYPTO_LIB_BLAKE2S_GENERIC if CRYPTO_ARCH_HAVE_LIB_BLAKE2S=n
+	help
+	  Enable the Blake2s library interface. This interface may be fulfilled
+	  by either the generic implementation or an arch-specific one, if one
+	  is available and enabled.
+
 config CRYPTO_ARCH_HAVE_LIB_CHACHA
 	tristate
 	help

lib/crypto/Makefile

@@ -10,6 +10,12 @@ libaes-y					:= aes.o
 obj-$(CONFIG_CRYPTO_LIB_ARC4)			+= libarc4.o
 libarc4-y					:= arc4.o
 
+obj-$(CONFIG_CRYPTO_LIB_BLAKE2S_GENERIC)	+= libblake2s-generic.o
+libblake2s-generic-y				+= blake2s-generic.o
+
+obj-$(CONFIG_CRYPTO_LIB_BLAKE2S)		+= libblake2s.o
+libblake2s-y					+= blake2s.o
+
 obj-$(CONFIG_CRYPTO_LIB_DES)			+= libdes.o
 libdes-y					:= des.o
 
@@ -18,3 +24,7 @@ libpoly1305-y					:= poly1305.o
 
 obj-$(CONFIG_CRYPTO_LIB_SHA256)			+= libsha256.o
 libsha256-y					:= sha256.o
+
+ifneq ($(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS),y)
+libblake2s-y					+= blake2s-selftest.o
+endif

lib/crypto/blake2s-generic.c

+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This is an implementation of the BLAKE2s hash and PRF functions.
+ *
+ * Information: https://blake2.net/
+ *
+ */
+
+#include <crypto/internal/blake2s.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bug.h>
+#include <asm/unaligned.h>
+
+static const u8 blake2s_sigma[10][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 },
+	{ 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
+	{ 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
+	{ 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
+	{ 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
+	{ 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
+	{ 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
+	{ 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
+	{ 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
+};
+
+static inline void blake2s_increment_counter(struct blake2s_state *state,
+					     const u32 inc)
+{
+	state->t[0] += inc;
+	state->t[1] += (state->t[0] < inc);
+}
+
+void blake2s_compress_generic(struct blake2s_state *state,const u8 *block,
+			      size_t nblocks, const u32 inc)
+{
+	u32 m[16];
+	u32 v[16];
+	int i;
+
+	WARN_ON(IS_ENABLED(DEBUG) &&
+		(nblocks > 1 && inc != BLAKE2S_BLOCK_SIZE));
+
+	while (nblocks > 0) {
+		blake2s_increment_counter(state, inc);
+		memcpy(m, block, BLAKE2S_BLOCK_SIZE);
+		le32_to_cpu_array(m, ARRAY_SIZE(m));
+		memcpy(v, state->h, 32);
+		v[ 8] = BLAKE2S_IV0;
+		v[ 9] = BLAKE2S_IV1;
+		v[10] = BLAKE2S_IV2;
+		v[11] = BLAKE2S_IV3;
+		v[12] = BLAKE2S_IV4 ^ state->t[0];
+		v[13] = BLAKE2S_IV5 ^ state->t[1];
+		v[14] = BLAKE2S_IV6 ^ state->f[0];
+		v[15] = BLAKE2S_IV7 ^ state->f[1];
+
+#define G(r, i, a, b, c, d) do { \
+	a += b + m[blake2s_sigma[r][2 * i + 0]]; \
+	d = ror32(d ^ a, 16); \
+	c += d; \
+	b = ror32(b ^ c, 12); \
+	a += b + m[blake2s_sigma[r][2 * i + 1]]; \
+	d = ror32(d ^ a, 8); \
+	c += d; \
+	b = ror32(b ^ c, 7); \
+} while (0)
+
+#define ROUND(r) do { \
+	G(r, 0, v[0], v[ 4], v[ 8], v[12]); \
+	G(r, 1, v[1], v[ 5], v[ 9], v[13]); \
+	G(r, 2, v[2], v[ 6], v[10], v[14]); \
+	G(r, 3, v[3], v[ 7], v[11], v[15]); \
+	G(r, 4, v[0], v[ 5], v[10], v[15]); \
+	G(r, 5, v[1], v[ 6], v[11], v[12]); \
+	G(r, 6, v[2], v[ 7], v[ 8], v[13]); \
+	G(r, 7, v[3], v[ 4], v[ 9], v[14]); \
+} while (0)
+		ROUND(0);
+		ROUND(1);
+		ROUND(2);
+		ROUND(3);
+		ROUND(4);
+		ROUND(5);
+		ROUND(6);
+		ROUND(7);
+		ROUND(8);
+		ROUND(9);
+
+#undef G
+#undef ROUND
+
+		for (i = 0; i < 8; ++i)
+			state->h[i] ^= v[i] ^ v[i + 8];
+
+		block += BLAKE2S_BLOCK_SIZE;
+		--nblocks;
+	}
+}
+
+EXPORT_SYMBOL(blake2s_compress_generic);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BLAKE2s hash function");
+MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");

lib/crypto/blake2s.c

+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ *
+ * This is an implementation of the BLAKE2s hash and PRF functions.
+ *
+ * Information: https://blake2.net/
+ *
+ */
+
+#include <crypto/internal/blake2s.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bug.h>
+#include <asm/unaligned.h>
+
+bool blake2s_selftest(void);
+
+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;
+}
+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);
+	memzero_explicit(state, sizeof(*state));
+}
+EXPORT_SYMBOL(blake2s_final);
+
+void blake2s256_hmac(u8 *out, const u8 *in, const u8 *key, const size_t inlen,
+		     const size_t keylen)
+{
+	struct blake2s_state state;
+	u8 x_key[BLAKE2S_BLOCK_SIZE] __aligned(__alignof__(u32)) = { 0 };
+	u8 i_hash[BLAKE2S_HASH_SIZE] __aligned(__alignof__(u32));
+	int i;
+
+	if (keylen > BLAKE2S_BLOCK_SIZE) {
+		blake2s_init(&state, BLAKE2S_HASH_SIZE);
+		blake2s_update(&state, key, keylen);
+		blake2s_final(&state, x_key);
+	} else
+		memcpy(x_key, key, keylen);
+
+	for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
+		x_key[i] ^= 0x36;
+
+	blake2s_init(&state, BLAKE2S_HASH_SIZE);
+	blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
+	blake2s_update(&state, in, inlen);
+	blake2s_final(&state, i_hash);
+
+	for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
+		x_key[i] ^= 0x5c ^ 0x36;
+
+	blake2s_init(&state, BLAKE2S_HASH_SIZE);
+	blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
+	blake2s_update(&state, i_hash, BLAKE2S_HASH_SIZE);
+	blake2s_final(&state, i_hash);
+
+	memcpy(out, i_hash, BLAKE2S_HASH_SIZE);
+	memzero_explicit(x_key, BLAKE2S_BLOCK_SIZE);
+	memzero_explicit(i_hash, BLAKE2S_HASH_SIZE);
+}
+EXPORT_SYMBOL(blake2s256_hmac);
+
+static int __init mod_init(void)
+{
+	if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) &&
+	    WARN_ON(!blake2s_selftest()))
+		return -ENODEV;
+	return 0;
+}
+
+static void __exit mod_exit(void)
+{
+}
+
+module_init(mod_init);
+module_exit(mod_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BLAKE2s hash function");
+MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");