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 * Copyright 2025 Google LLC 5 * 6 * This is an implementation of the BLAKE2b hash and PRF functions. 7 * 8 * Information: https://blake2.net/ 9 */ 10 11 #include <crypto/blake2b.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 20 static const u8 blake2b_sigma[12][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 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 }, 32 { 14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3 } 33 }; 34 35 static inline void blake2b_increment_counter(struct blake2b_ctx *ctx, u32 inc) 36 { 37 ctx->t[0] += inc; 38 ctx->t[1] += (ctx->t[0] < inc); 39 } 40 41 static void __maybe_unused 42 blake2b_compress_generic(struct blake2b_ctx *ctx, 43 const u8 *data, size_t nblocks, u32 inc) 44 { 45 u64 m[16]; 46 u64 v[16]; 47 int i; 48 49 WARN_ON(IS_ENABLED(DEBUG) && 50 (nblocks > 1 && inc != BLAKE2B_BLOCK_SIZE)); 51 52 while (nblocks > 0) { 53 blake2b_increment_counter(ctx, inc); 54 memcpy(m, data, BLAKE2B_BLOCK_SIZE); 55 le64_to_cpu_array(m, ARRAY_SIZE(m)); 56 memcpy(v, ctx->h, 64); 57 v[ 8] = BLAKE2B_IV0; 58 v[ 9] = BLAKE2B_IV1; 59 v[10] = BLAKE2B_IV2; 60 v[11] = BLAKE2B_IV3; 61 v[12] = BLAKE2B_IV4 ^ ctx->t[0]; 62 v[13] = BLAKE2B_IV5 ^ ctx->t[1]; 63 v[14] = BLAKE2B_IV6 ^ ctx->f[0]; 64 v[15] = BLAKE2B_IV7 ^ ctx->f[1]; 65 66 #define G(r, i, a, b, c, d) do { \ 67 a += b + m[blake2b_sigma[r][2 * i + 0]]; \ 68 d = ror64(d ^ a, 32); \ 69 c += d; \ 70 b = ror64(b ^ c, 24); \ 71 a += b + m[blake2b_sigma[r][2 * i + 1]]; \ 72 d = ror64(d ^ a, 16); \ 73 c += d; \ 74 b = ror64(b ^ c, 63); \ 75 } while (0) 76 77 #ifdef CONFIG_64BIT 78 /* 79 * Unroll the rounds loop to enable constant-folding of the 80 * blake2b_sigma values. Seems worthwhile on 64-bit kernels. 81 * Not worthwhile on 32-bit kernels because the code size is 82 * already so large there due to BLAKE2b using 64-bit words. 83 */ 84 unrolled_full 85 #endif 86 for (int r = 0; r < 12; r++) { 87 G(r, 0, v[0], v[4], v[8], v[12]); 88 G(r, 1, v[1], v[5], v[9], v[13]); 89 G(r, 2, v[2], v[6], v[10], v[14]); 90 G(r, 3, v[3], v[7], v[11], v[15]); 91 G(r, 4, v[0], v[5], v[10], v[15]); 92 G(r, 5, v[1], v[6], v[11], v[12]); 93 G(r, 6, v[2], v[7], v[8], v[13]); 94 G(r, 7, v[3], v[4], v[9], v[14]); 95 } 96 #undef G 97 98 for (i = 0; i < 8; ++i) 99 ctx->h[i] ^= v[i] ^ v[i + 8]; 100 101 data += BLAKE2B_BLOCK_SIZE; 102 --nblocks; 103 } 104 } 105 106 #ifdef CONFIG_CRYPTO_LIB_BLAKE2B_ARCH 107 #include "blake2b.h" /* $(SRCARCH)/blake2b.h */ 108 #else 109 #define blake2b_compress blake2b_compress_generic 110 #endif 111 112 static inline void blake2b_set_lastblock(struct blake2b_ctx *ctx) 113 { 114 ctx->f[0] = -1; 115 } 116 117 void blake2b_update(struct blake2b_ctx *ctx, const u8 *in, size_t inlen) 118 { 119 const size_t fill = BLAKE2B_BLOCK_SIZE - ctx->buflen; 120 121 if (unlikely(!inlen)) 122 return; 123 if (inlen > fill) { 124 memcpy(ctx->buf + ctx->buflen, in, fill); 125 blake2b_compress(ctx, ctx->buf, 1, BLAKE2B_BLOCK_SIZE); 126 ctx->buflen = 0; 127 in += fill; 128 inlen -= fill; 129 } 130 if (inlen > BLAKE2B_BLOCK_SIZE) { 131 const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2B_BLOCK_SIZE); 132 133 blake2b_compress(ctx, in, nblocks - 1, BLAKE2B_BLOCK_SIZE); 134 in += BLAKE2B_BLOCK_SIZE * (nblocks - 1); 135 inlen -= BLAKE2B_BLOCK_SIZE * (nblocks - 1); 136 } 137 memcpy(ctx->buf + ctx->buflen, in, inlen); 138 ctx->buflen += inlen; 139 } 140 EXPORT_SYMBOL(blake2b_update); 141 142 void blake2b_final(struct blake2b_ctx *ctx, u8 *out) 143 { 144 WARN_ON(IS_ENABLED(DEBUG) && !out); 145 blake2b_set_lastblock(ctx); 146 memset(ctx->buf + ctx->buflen, 0, 147 BLAKE2B_BLOCK_SIZE - ctx->buflen); /* Padding */ 148 blake2b_compress(ctx, ctx->buf, 1, ctx->buflen); 149 cpu_to_le64_array(ctx->h, ARRAY_SIZE(ctx->h)); 150 memcpy(out, ctx->h, ctx->outlen); 151 memzero_explicit(ctx, sizeof(*ctx)); 152 } 153 EXPORT_SYMBOL(blake2b_final); 154 155 #ifdef blake2b_mod_init_arch 156 static int __init blake2b_mod_init(void) 157 { 158 blake2b_mod_init_arch(); 159 return 0; 160 } 161 subsys_initcall(blake2b_mod_init); 162 163 static void __exit blake2b_mod_exit(void) 164 { 165 } 166 module_exit(blake2b_mod_exit); 167 #endif 168 169 MODULE_DESCRIPTION("BLAKE2b hash function"); 170 MODULE_LICENSE("GPL"); 171