lib/crypto/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/internal/blake2s.h>
  12 #include <linux/types.h>
  13 #include <linux/string.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/bug.h>
  18 #include <asm/unaligned.h>
  19
  20 void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen)
  21 {
  22         const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
  23
  24         if (unlikely(!inlen))
  25                 return;
  26         if (inlen > fill) {
  27                 memcpy(state->buf + state->buflen, in, fill);
  28                 if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S))
  29                         blake2s_compress_arch(state, state->buf, 1,
  30                                               BLAKE2S_BLOCK_SIZE);
  31                 else
  32                         blake2s_compress_generic(state, state->buf, 1,
  33                                                  BLAKE2S_BLOCK_SIZE);
  34                 state->buflen = 0;
  35                 in += fill;
  36                 inlen -= fill;
  37         }
  38         if (inlen > BLAKE2S_BLOCK_SIZE) {
  39                 const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
  40                 /* Hash one less (full) block than strictly possible */
  41                 if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S))
  42                         blake2s_compress_arch(state, in, nblocks - 1,
  43                                               BLAKE2S_BLOCK_SIZE);
  44                 else
  45                         blake2s_compress_generic(state, in, nblocks - 1,
  46                                                  BLAKE2S_BLOCK_SIZE);
  47                 in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
  48                 inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
  49         }
  50         memcpy(state->buf + state->buflen, in, inlen);
  51         state->buflen += inlen;
  52 }
  53 EXPORT_SYMBOL(blake2s_update);
  54
  55 void blake2s_final(struct blake2s_state *state, u8 *out)
  56 {
  57         WARN_ON(IS_ENABLED(DEBUG) && !out);
  58         blake2s_set_lastblock(state);
  59         memset(state->buf + state->buflen, 0,
  60                BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
  61         if (IS_ENABLED(CONFIG_CRYPTO_ARCH_HAVE_LIB_BLAKE2S))
  62                 blake2s_compress_arch(state, state->buf, 1, state->buflen);
  63         else
  64                 blake2s_compress_generic(state, state->buf, 1, state->buflen);
  65         cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
  66         memcpy(out, state->h, state->outlen);
  67         memzero_explicit(state, sizeof(*state));
  68 }
  69 EXPORT_SYMBOL(blake2s_final);
  70
  71 void blake2s256_hmac(u8 *out, const u8 *in, const u8 *key, const size_t inlen,
  72                      const size_t keylen)
  73 {
  74         struct blake2s_state state;
  75         u8 x_key[BLAKE2S_BLOCK_SIZE] __aligned(__alignof__(u32)) = { 0 };
  76         u8 i_hash[BLAKE2S_HASH_SIZE] __aligned(__alignof__(u32));
  77         int i;
  78
  79         if (keylen > BLAKE2S_BLOCK_SIZE) {
  80                 blake2s_init(&state, BLAKE2S_HASH_SIZE);
  81                 blake2s_update(&state, key, keylen);
  82                 blake2s_final(&state, x_key);
  83         } else
  84                 memcpy(x_key, key, keylen);
  85
  86         for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
  87                 x_key[i] ^= 0x36;
  88
  89         blake2s_init(&state, BLAKE2S_HASH_SIZE);
  90         blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
  91         blake2s_update(&state, in, inlen);
  92         blake2s_final(&state, i_hash);
  93
  94         for (i = 0; i < BLAKE2S_BLOCK_SIZE; ++i)
  95                 x_key[i] ^= 0x5c ^ 0x36;
  96
  97         blake2s_init(&state, BLAKE2S_HASH_SIZE);
  98         blake2s_update(&state, x_key, BLAKE2S_BLOCK_SIZE);
  99         blake2s_update(&state, i_hash, BLAKE2S_HASH_SIZE);
 100         blake2s_final(&state, i_hash);
 101
 102         memcpy(out, i_hash, BLAKE2S_HASH_SIZE);
 103         memzero_explicit(x_key, BLAKE2S_BLOCK_SIZE);
 104         memzero_explicit(i_hash, BLAKE2S_HASH_SIZE);
 105 }
 106 EXPORT_SYMBOL(blake2s256_hmac);
 107
 108 static int __init mod_init(void)
 109 {
 110         if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) &&
 111             WARN_ON(!blake2s_selftest()))
 112                 return -ENODEV;
 113         return 0;
 114 }
 115
 116 static void __exit mod_exit(void)
 117 {
 118 }
 119
 120 module_init(mod_init);
 121 module_exit(mod_exit);
 122 MODULE_LICENSE("GPL v2");
 123 MODULE_DESCRIPTION("BLAKE2s hash function");
 124 MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");