From 23a16c9533ed92cc639c8f5bd9eb104809fe2919 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Fri, 17 Oct 2025 21:31:02 -0700 Subject: [PATCH] lib/crypto: blake2b: Add BLAKE2b library functions Add a library API for BLAKE2b, closely modeled after the BLAKE2s API. This will allow in-kernel users such as btrfs to use BLAKE2b without going through the generic crypto layer. In addition, as usual the BLAKE2b crypto_shash algorithms will be reimplemented on top of this. Note: to create lib/crypto/blake2b.c I made a copy of lib/crypto/blake2s.c and made the updates from BLAKE2s => BLAKE2b. This way, the BLAKE2s and BLAKE2b code is kept consistent. Therefore, it borrows the SPDX-License-Identifier and Copyright from lib/crypto/blake2s.c rather than crypto/blake2b_generic.c. The library API uses 'struct blake2b_ctx', consistent with other lib/crypto/ APIs. The existing 'struct blake2b_state' will be removed once the blake2b crypto_shash algorithms are updated to stop using it. Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20251018043106.375964-7-ebiggers@kernel.org Signed-off-by: Eric Biggers --- include/crypto/blake2b.h | 133 ++++++++++++++++++++--- include/crypto/internal/blake2b.h | 17 ++- lib/crypto/Kconfig | 10 ++ lib/crypto/Makefile | 9 ++ lib/crypto/blake2b.c | 174 ++++++++++++++++++++++++++++++ 5 files changed, 330 insertions(+), 13 deletions(-) create mode 100644 lib/crypto/blake2b.c diff --git a/include/crypto/blake2b.h b/include/crypto/blake2b.h index dd7694477e50f..4879e2ec26867 100644 --- a/include/crypto/blake2b.h +++ b/include/crypto/blake2b.h @@ -28,6 +28,25 @@ enum blake2b_lengths { BLAKE2B_512_HASH_SIZE = 64, }; +/** + * struct blake2b_ctx - Context for hashing a message with BLAKE2b + * @h: compression function state + * @t: block counter + * @f: finalization indicator + * @buf: partial block buffer; 'buflen' bytes are valid + * @buflen: number of bytes buffered in @buf + * @outlen: length of output hash value in bytes, at most BLAKE2B_HASH_SIZE + */ +struct blake2b_ctx { + /* 'h', 't', and 'f' are used in assembly code, so keep them as-is. */ + u64 h[8]; + u64 t[2]; + u64 f[2]; + u8 buf[BLAKE2B_BLOCK_SIZE]; + unsigned int buflen; + unsigned int outlen; +}; + enum blake2b_iv { BLAKE2B_IV0 = 0x6A09E667F3BCC908ULL, BLAKE2B_IV1 = 0xBB67AE8584CAA73BULL, @@ -39,19 +58,109 @@ enum blake2b_iv { BLAKE2B_IV7 = 0x5BE0CD19137E2179ULL, }; -static inline void __blake2b_init(struct blake2b_state *state, size_t outlen, - size_t keylen) +static inline void __blake2b_init(struct blake2b_ctx *ctx, size_t outlen, + const void *key, size_t keylen) +{ + ctx->h[0] = BLAKE2B_IV0 ^ (0x01010000 | keylen << 8 | outlen); + ctx->h[1] = BLAKE2B_IV1; + ctx->h[2] = BLAKE2B_IV2; + ctx->h[3] = BLAKE2B_IV3; + ctx->h[4] = BLAKE2B_IV4; + ctx->h[5] = BLAKE2B_IV5; + ctx->h[6] = BLAKE2B_IV6; + ctx->h[7] = BLAKE2B_IV7; + ctx->t[0] = 0; + ctx->t[1] = 0; + ctx->f[0] = 0; + ctx->f[1] = 0; + ctx->buflen = 0; + ctx->outlen = outlen; + if (keylen) { + memcpy(ctx->buf, key, keylen); + memset(&ctx->buf[keylen], 0, BLAKE2B_BLOCK_SIZE - keylen); + ctx->buflen = BLAKE2B_BLOCK_SIZE; + } +} + +/** + * blake2b_init() - Initialize a BLAKE2b context for a new message (unkeyed) + * @ctx: the context to initialize + * @outlen: length of output hash value in bytes, at most BLAKE2B_HASH_SIZE + * + * Context: Any context. + */ +static inline void blake2b_init(struct blake2b_ctx *ctx, size_t outlen) +{ + __blake2b_init(ctx, outlen, NULL, 0); +} + +/** + * blake2b_init_key() - Initialize a BLAKE2b context for a new message (keyed) + * @ctx: the context to initialize + * @outlen: length of output hash value in bytes, at most BLAKE2B_HASH_SIZE + * @key: the key + * @keylen: the key length in bytes, at most BLAKE2B_KEY_SIZE + * + * Context: Any context. + */ +static inline void blake2b_init_key(struct blake2b_ctx *ctx, size_t outlen, + const void *key, size_t keylen) +{ + WARN_ON(IS_ENABLED(DEBUG) && (!outlen || outlen > BLAKE2B_HASH_SIZE || + !key || !keylen || keylen > BLAKE2B_KEY_SIZE)); + + __blake2b_init(ctx, outlen, key, keylen); +} + +/** + * blake2b_update() - Update a BLAKE2b context with message data + * @ctx: the context to update; must have been initialized + * @in: the message data + * @inlen: the data length in bytes + * + * This can be called any number of times. + * + * Context: Any context. + */ +void blake2b_update(struct blake2b_ctx *ctx, const u8 *in, size_t inlen); + +/** + * blake2b_final() - Finish computing a BLAKE2b hash + * @ctx: the context to finalize; must have been initialized + * @out: (output) the resulting BLAKE2b hash. Its length will be equal to the + * @outlen that was passed to blake2b_init() or blake2b_init_key(). + * + * After finishing, this zeroizes @ctx. So the caller does not need to do it. + * + * Context: Any context. + */ +void blake2b_final(struct blake2b_ctx *ctx, u8 *out); + +/** + * blake2b() - Compute BLAKE2b hash in one shot + * @key: the key, or NULL for an unkeyed hash + * @keylen: the key length in bytes (at most BLAKE2B_KEY_SIZE), or 0 for an + * unkeyed hash + * @in: the message data + * @inlen: the data length in bytes + * @out: (output) the resulting BLAKE2b hash, with length @outlen + * @outlen: length of output hash value in bytes, at most BLAKE2B_HASH_SIZE + * + * Context: Any context. + */ +static inline void blake2b(const u8 *key, size_t keylen, + const u8 *in, size_t inlen, + u8 *out, size_t outlen) { - state->h[0] = BLAKE2B_IV0 ^ (0x01010000 | keylen << 8 | outlen); - state->h[1] = BLAKE2B_IV1; - state->h[2] = BLAKE2B_IV2; - state->h[3] = BLAKE2B_IV3; - state->h[4] = BLAKE2B_IV4; - state->h[5] = BLAKE2B_IV5; - state->h[6] = BLAKE2B_IV6; - state->h[7] = BLAKE2B_IV7; - state->t[0] = 0; - state->t[1] = 0; + struct blake2b_ctx ctx; + + WARN_ON(IS_ENABLED(DEBUG) && ((!in && inlen > 0) || !out || !outlen || + outlen > BLAKE2B_HASH_SIZE || keylen > BLAKE2B_KEY_SIZE || + (!key && keylen))); + + __blake2b_init(&ctx, outlen, key, keylen); + blake2b_update(&ctx, in, inlen); + blake2b_final(&ctx, out); } #endif /* _CRYPTO_BLAKE2B_H */ diff --git a/include/crypto/internal/blake2b.h b/include/crypto/internal/blake2b.h index 3e09e24853060..3712df69def18 100644 --- a/include/crypto/internal/blake2b.h +++ b/include/crypto/internal/blake2b.h @@ -57,13 +57,28 @@ static inline int crypto_blake2b_setkey(struct crypto_shash *tfm, return 0; } +static inline void __crypto_blake2b_init(struct blake2b_state *state, + size_t outlen, size_t keylen) +{ + state->h[0] = BLAKE2B_IV0 ^ (0x01010000 | keylen << 8 | outlen); + state->h[1] = BLAKE2B_IV1; + state->h[2] = BLAKE2B_IV2; + state->h[3] = BLAKE2B_IV3; + state->h[4] = BLAKE2B_IV4; + state->h[5] = BLAKE2B_IV5; + state->h[6] = BLAKE2B_IV6; + state->h[7] = BLAKE2B_IV7; + state->t[0] = 0; + state->t[1] = 0; +} + static inline int crypto_blake2b_init(struct shash_desc *desc) { const struct blake2b_tfm_ctx *tctx = crypto_shash_ctx(desc->tfm); struct blake2b_state *state = shash_desc_ctx(desc); unsigned int outlen = crypto_shash_digestsize(desc->tfm); - __blake2b_init(state, outlen, tctx->keylen); + __crypto_blake2b_init(state, outlen, tctx->keylen); return tctx->keylen ? crypto_shash_update(desc, tctx->key, BLAKE2B_BLOCK_SIZE) : 0; } diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index 8886055e938f2..918378b7e8338 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -28,6 +28,16 @@ config CRYPTO_LIB_ARC4 config CRYPTO_LIB_GF128MUL tristate +config CRYPTO_LIB_BLAKE2B + tristate + help + The BLAKE2b library functions. Select this if your module uses any of + the functions from . + +config CRYPTO_LIB_BLAKE2B_ARCH + bool + depends on CRYPTO_LIB_BLAKE2B && !UML + # BLAKE2s support is always built-in, so there's no CRYPTO_LIB_BLAKE2S option. config CRYPTO_LIB_BLAKE2S_ARCH diff --git a/lib/crypto/Makefile b/lib/crypto/Makefile index bded351aeacef..f863417b16817 100644 --- a/lib/crypto/Makefile +++ b/lib/crypto/Makefile @@ -31,6 +31,15 @@ obj-$(CONFIG_CRYPTO_LIB_GF128MUL) += gf128mul.o ################################################################################ +obj-$(CONFIG_CRYPTO_LIB_BLAKE2B) += libblake2b.o +libblake2b-y := blake2b.o +CFLAGS_blake2b.o := -Wframe-larger-than=4096 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105930 +ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2B_ARCH),y) +CFLAGS_blake2b.o += -I$(src)/$(SRCARCH) +endif # CONFIG_CRYPTO_LIB_BLAKE2B_ARCH + +################################################################################ + # blake2s is used by the /dev/random driver which is always builtin obj-y += blake2s.o ifeq ($(CONFIG_CRYPTO_LIB_BLAKE2S_ARCH),y) diff --git a/lib/crypto/blake2b.c b/lib/crypto/blake2b.c new file mode 100644 index 0000000000000..09c6d65d8a6e6 --- /dev/null +++ b/lib/crypto/blake2b.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT +/* + * Copyright (C) 2015-2019 Jason A. Donenfeld . All Rights Reserved. + * Copyright 2025 Google LLC + * + * This is an implementation of the BLAKE2b hash and PRF functions. + * + * Information: https://blake2.net/ + */ + +#include +#include +#include +#include +#include +#include +#include + +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 }, + { 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 }, + { 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 } +}; + +static inline void blake2b_increment_counter(struct blake2b_ctx *ctx, u32 inc) +{ + ctx->t[0] += inc; + ctx->t[1] += (ctx->t[0] < inc); +} + +static void __maybe_unused +blake2b_compress_generic(struct blake2b_ctx *ctx, + const u8 *data, size_t nblocks, u32 inc) +{ + u64 m[16]; + u64 v[16]; + int i; + + WARN_ON(IS_ENABLED(DEBUG) && + (nblocks > 1 && inc != BLAKE2B_BLOCK_SIZE)); + + while (nblocks > 0) { + blake2b_increment_counter(ctx, inc); + memcpy(m, data, BLAKE2B_BLOCK_SIZE); + le64_to_cpu_array(m, ARRAY_SIZE(m)); + memcpy(v, ctx->h, 64); + v[ 8] = BLAKE2B_IV0; + v[ 9] = BLAKE2B_IV1; + v[10] = BLAKE2B_IV2; + v[11] = BLAKE2B_IV3; + v[12] = BLAKE2B_IV4 ^ ctx->t[0]; + v[13] = BLAKE2B_IV5 ^ ctx->t[1]; + v[14] = BLAKE2B_IV6 ^ ctx->f[0]; + v[15] = BLAKE2B_IV7 ^ ctx->f[1]; + +#define G(r, i, a, b, c, d) do { \ + a += b + m[blake2b_sigma[r][2 * i + 0]]; \ + d = ror64(d ^ a, 32); \ + c += d; \ + b = ror64(b ^ c, 24); \ + a += b + m[blake2b_sigma[r][2 * i + 1]]; \ + d = ror64(d ^ a, 16); \ + c += d; \ + b = ror64(b ^ c, 63); \ +} 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); + ROUND(10); + ROUND(11); + +#undef G +#undef ROUND + + for (i = 0; i < 8; ++i) + ctx->h[i] ^= v[i] ^ v[i + 8]; + + data += BLAKE2B_BLOCK_SIZE; + --nblocks; + } +} + +#ifdef CONFIG_CRYPTO_LIB_BLAKE2B_ARCH +#include "blake2b.h" /* $(SRCARCH)/blake2b.h */ +#else +#define blake2b_compress blake2b_compress_generic +#endif + +static inline void blake2b_set_lastblock(struct blake2b_ctx *ctx) +{ + ctx->f[0] = -1; +} + +void blake2b_update(struct blake2b_ctx *ctx, const u8 *in, size_t inlen) +{ + const size_t fill = BLAKE2B_BLOCK_SIZE - ctx->buflen; + + if (unlikely(!inlen)) + return; + if (inlen > fill) { + memcpy(ctx->buf + ctx->buflen, in, fill); + blake2b_compress(ctx, ctx->buf, 1, BLAKE2B_BLOCK_SIZE); + ctx->buflen = 0; + in += fill; + inlen -= fill; + } + if (inlen > BLAKE2B_BLOCK_SIZE) { + const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2B_BLOCK_SIZE); + + blake2b_compress(ctx, in, nblocks - 1, BLAKE2B_BLOCK_SIZE); + in += BLAKE2B_BLOCK_SIZE * (nblocks - 1); + inlen -= BLAKE2B_BLOCK_SIZE * (nblocks - 1); + } + memcpy(ctx->buf + ctx->buflen, in, inlen); + ctx->buflen += inlen; +} +EXPORT_SYMBOL(blake2b_update); + +void blake2b_final(struct blake2b_ctx *ctx, u8 *out) +{ + WARN_ON(IS_ENABLED(DEBUG) && !out); + blake2b_set_lastblock(ctx); + memset(ctx->buf + ctx->buflen, 0, + BLAKE2B_BLOCK_SIZE - ctx->buflen); /* Padding */ + blake2b_compress(ctx, ctx->buf, 1, ctx->buflen); + cpu_to_le64_array(ctx->h, ARRAY_SIZE(ctx->h)); + memcpy(out, ctx->h, ctx->outlen); + memzero_explicit(ctx, sizeof(*ctx)); +} +EXPORT_SYMBOL(blake2b_final); + +#ifdef blake2b_mod_init_arch +static int __init blake2b_mod_init(void) +{ + blake2b_mod_init_arch(); + return 0; +} +subsys_initcall(blake2b_mod_init); + +static void __exit blake2b_mod_exit(void) +{ +} +module_exit(blake2b_mod_exit); +#endif + +MODULE_DESCRIPTION("BLAKE2b hash function"); +MODULE_LICENSE("GPL"); -- 2.47.3