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