xref: /openbmc/linux/lib/crypto/blake2s.c (revision fb574682)
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>");
127