blake2s.c

  1// SPDX-License-Identifier: GPL-2.0 OR MIT
  2/*
  3 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  4 *
  5 * This is an implementation of the BLAKE2s hash and PRF functions.
  6 *
  7 * Information: https://blake2.net/
  8 *
  9 */
 10
 11#include <crypto/blake2s.h>
 12#include <linux/bug.h>
 13#include <linux/export.h>
 14#include <linux/kernel.h>
 15#include <linux/module.h>
 16#include <linux/string.h>
 17#include <linux/unroll.h>
 18#include <linux/types.h>
 19
 20static const u8 blake2s_sigma[10][16] = {
 21	{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 },
 22	{ 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 },
 23	{ 11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4 },
 24	{ 7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8 },
 25	{ 9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13 },
 26	{ 2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9 },
 27	{ 12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11 },
 28	{ 13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10 },
 29	{ 6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5 },
 30	{ 10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0 },
 31};
 32
 33static inline void blake2s_increment_counter(struct blake2s_ctx *ctx, u32 inc)
 34{
 35	ctx->t[0] += inc;
 36	ctx->t[1] += (ctx->t[0] < inc);
 37}
 38
 39static void __maybe_unused
 40blake2s_compress_generic(struct blake2s_ctx *ctx,
 41			 const u8 *data, size_t nblocks, u32 inc)
 42{
 43	u32 m[16];
 44	u32 v[16];
 45	int i;
 46
 47	WARN_ON(IS_ENABLED(DEBUG) &&
 48		(nblocks > 1 && inc != BLAKE2S_BLOCK_SIZE));
 49
 50	while (nblocks > 0) {
 51		blake2s_increment_counter(ctx, inc);
 52		memcpy(m, data, BLAKE2S_BLOCK_SIZE);
 53		le32_to_cpu_array(m, ARRAY_SIZE(m));
 54		memcpy(v, ctx->h, 32);
 55		v[ 8] = BLAKE2S_IV0;
 56		v[ 9] = BLAKE2S_IV1;
 57		v[10] = BLAKE2S_IV2;
 58		v[11] = BLAKE2S_IV3;
 59		v[12] = BLAKE2S_IV4 ^ ctx->t[0];
 60		v[13] = BLAKE2S_IV5 ^ ctx->t[1];
 61		v[14] = BLAKE2S_IV6 ^ ctx->f[0];
 62		v[15] = BLAKE2S_IV7 ^ ctx->f[1];
 63
 64#define G(r, i, a, b, c, d) do { \
 65	a += b + m[blake2s_sigma[r][2 * i + 0]]; \
 66	d = ror32(d ^ a, 16); \
 67	c += d; \
 68	b = ror32(b ^ c, 12); \
 69	a += b + m[blake2s_sigma[r][2 * i + 1]]; \
 70	d = ror32(d ^ a, 8); \
 71	c += d; \
 72	b = ror32(b ^ c, 7); \
 73} while (0)
 74
 75		/*
 76		 * Unroll the rounds loop to enable constant-folding of the
 77		 * blake2s_sigma values.
 78		 */
 79		unrolled_full
 80		for (int r = 0; r < 10; r++) {
 81			G(r, 0, v[0], v[4], v[8], v[12]);
 82			G(r, 1, v[1], v[5], v[9], v[13]);
 83			G(r, 2, v[2], v[6], v[10], v[14]);
 84			G(r, 3, v[3], v[7], v[11], v[15]);
 85			G(r, 4, v[0], v[5], v[10], v[15]);
 86			G(r, 5, v[1], v[6], v[11], v[12]);
 87			G(r, 6, v[2], v[7], v[8], v[13]);
 88			G(r, 7, v[3], v[4], v[9], v[14]);
 89		}
 90#undef G
 91
 92		for (i = 0; i < 8; ++i)
 93			ctx->h[i] ^= v[i] ^ v[i + 8];
 94
 95		data += BLAKE2S_BLOCK_SIZE;
 96		--nblocks;
 97	}
 98}
 99
100#ifdef CONFIG_CRYPTO_LIB_BLAKE2S_ARCH
101#include "blake2s.h" /* $(SRCARCH)/blake2s.h */
102#else
103#define blake2s_compress blake2s_compress_generic
104#endif
105
106static inline void blake2s_set_lastblock(struct blake2s_ctx *ctx)
107{
108	ctx->f[0] = -1;
109}
110
111void blake2s_update(struct blake2s_ctx *ctx, const u8 *in, size_t inlen)
112{
113	const size_t fill = BLAKE2S_BLOCK_SIZE - ctx->buflen;
114
115	if (unlikely(!inlen))
116		return;
117	if (inlen > fill) {
118		memcpy(ctx->buf + ctx->buflen, in, fill);
119		blake2s_compress(ctx, ctx->buf, 1, BLAKE2S_BLOCK_SIZE);
120		ctx->buflen = 0;
121		in += fill;
122		inlen -= fill;
123	}
124	if (inlen > BLAKE2S_BLOCK_SIZE) {
125		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
126
127		blake2s_compress(ctx, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
128		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
129		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
130	}
131	memcpy(ctx->buf + ctx->buflen, in, inlen);
132	ctx->buflen += inlen;
133}
134EXPORT_SYMBOL(blake2s_update);
135
136void blake2s_final(struct blake2s_ctx *ctx, u8 *out)
137{
138	WARN_ON(IS_ENABLED(DEBUG) && !out);
139	blake2s_set_lastblock(ctx);
140	memset(ctx->buf + ctx->buflen, 0,
141	       BLAKE2S_BLOCK_SIZE - ctx->buflen); /* Padding */
142	blake2s_compress(ctx, ctx->buf, 1, ctx->buflen);
143	cpu_to_le32_array(ctx->h, ARRAY_SIZE(ctx->h));
144	memcpy(out, ctx->h, ctx->outlen);
145	memzero_explicit(ctx, sizeof(*ctx));
146}
147EXPORT_SYMBOL(blake2s_final);
148
149#ifdef blake2s_mod_init_arch
150static int __init blake2s_mod_init(void)
151{
152	blake2s_mod_init_arch();
153	return 0;
154}
155subsys_initcall(blake2s_mod_init);
156#endif
157
158MODULE_DESCRIPTION("BLAKE2s hash function");
159MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");