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>

1 files changed, 106 insertions, 0 deletions

diff --git a/include/crypto/blake2s.h b/include/crypto/blake2s.h
new file mode 100644
index 000000000000..b471deac28ff
--- /dev/null
+++ b/include/crypto/blake2s.h
@@ -0,0 +1,106 @@
+/* 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 */