xref: /openbmc/linux/lib/crypto/blake2s.c (revision e40573a4)
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 
19 static inline void blake2s_set_lastblock(struct blake2s_state *state)
20 {
21 	state->f[0] = -1;
22 }
23 
24 void blake2s_update(struct blake2s_state *state, const u8 *in, size_t inlen)
25 {
26 	const size_t fill = BLAKE2S_BLOCK_SIZE - state->buflen;
27 
28 	if (unlikely(!inlen))
29 		return;
30 	if (inlen > fill) {
31 		memcpy(state->buf + state->buflen, in, fill);
32 		blake2s_compress(state, state->buf, 1, BLAKE2S_BLOCK_SIZE);
33 		state->buflen = 0;
34 		in += fill;
35 		inlen -= fill;
36 	}
37 	if (inlen > BLAKE2S_BLOCK_SIZE) {
38 		const size_t nblocks = DIV_ROUND_UP(inlen, BLAKE2S_BLOCK_SIZE);
39 		blake2s_compress(state, in, nblocks - 1, BLAKE2S_BLOCK_SIZE);
40 		in += BLAKE2S_BLOCK_SIZE * (nblocks - 1);
41 		inlen -= BLAKE2S_BLOCK_SIZE * (nblocks - 1);
42 	}
43 	memcpy(state->buf + state->buflen, in, inlen);
44 	state->buflen += inlen;
45 }
46 EXPORT_SYMBOL(blake2s_update);
47 
48 void blake2s_final(struct blake2s_state *state, u8 *out)
49 {
50 	WARN_ON(IS_ENABLED(DEBUG) && !out);
51 	blake2s_set_lastblock(state);
52 	memset(state->buf + state->buflen, 0,
53 	       BLAKE2S_BLOCK_SIZE - state->buflen); /* Padding */
54 	blake2s_compress(state, state->buf, 1, state->buflen);
55 	cpu_to_le32_array(state->h, ARRAY_SIZE(state->h));
56 	memcpy(out, state->h, state->outlen);
57 	memzero_explicit(state, sizeof(*state));
58 }
59 EXPORT_SYMBOL(blake2s_final);
60 
61 static int __init blake2s_mod_init(void)
62 {
63 	if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) &&
64 	    WARN_ON(!blake2s_selftest()))
65 		return -ENODEV;
66 	return 0;
67 }
68 
69 module_init(blake2s_mod_init);
70 MODULE_LICENSE("GPL v2");
71 MODULE_DESCRIPTION("BLAKE2s hash function");
72 MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
73