xref: /openbmc/linux/lib/crypto/blake2s.c (revision 7e60e389)
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>");
125